Table of contents

PREFACE

On behalf of the 2nd Nommensen International Conference on Technology and Engineering, I would like to welcome you all speakers and participants to our campus in Medan. This city is fascinating with its culinary tourism offering tropical fruit like durian and various food and cakes that spoil our tongue. Beside its culinary tourism, the city of Medan is close to a dynamic business city with relevant past in agriculture and plantation. We hope you will have the opportunity to enjoy the food and your time while staying in this city.

This conference is the second time the NICTE series was conducted by our university. The current theme is "Sustainable Engineering, and Technology Innovation and Application." The theme is selected with the objective to bring more innovation in technology application to the current development in this city and the whole country of Indonesia. The great effort dedicated by our government to expedite the construction of massive infrastructures requires more technology innovation and application. Our contribution to this conference however small is also of valuable input to the current government effort in developing this country.

I would like to take this opprtunity to thank all the committe, speakers, authors, reviewers and participants who dedicated their effort for the successfull execution of this conference. Without your contribution, we simply could not have had this conference.

List of Keynote Speakers, Reviewer, Administrative and Supporting Staff are available in this pdf.

All papers published in this volume of IOP Conference Series: Materials Science and Engineering have been peer reviewed through processes administered by the proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

This paper was aimed to share our experience in using CFRP in the case of retrofit of the ramp structure in palm oil mill in South Sumatera with a total length of 104 m and a width of 20 m, which consists of the primary beams (30 cm × 70 cm) span 8 m, the secondary beams (25 cm × 40 cm), and the slabs (thickness 20 cm). This ramp was cracked in the beams and the slabs after the five-year operation. In the first-year operation, no crack was found. However, from the second year until the fifth year, the cracks increased. After investigating in the field, we found a flexure crack in the primary beams, the secondary beams, and the slabs. In the drawing, we found that the bar was a plane bar and the quality of the concrete average was fc' 20 MPa. The Imposed loads for the vehicular traffic were designed with 12 tons. In the next step, we made a static calculation to check all designs. The results from the static calculation were that the capacity of the bar was sufficient, and the deflection was still under the allowed limit. The cracks mostly occurred in the Ramp structure. In the parking area in another building, there was no crack found. Thus the solution for this ramp was repaired the concrete from the cracks then strengthen it using CFRP. Strengthening of the primary beams used two strips of a fiber-reinforced composite or plastic material type with a thickness of 1.2 mm and a width of 10 cm. The capacity of the positive moment and the negative moment would increase the capacity about 64%. For the strengthening of the secondary beams using two strips of CFRP with a thickness of 1.2 mm and a width of 10 cm, the capacity of the positive moment and the negative moment would increase the capacity about 145%. For the strengthening of the thickness of the slabs 20 cm using one strip with a thickness of 1.2 mm and a width of 10 cm, the capacity of the positive moment and the negative moment would increase the capacity about 186%. The use of CFRP as the strengthening of the beams and the slabs was significant in increasing the moment capacity for the beams and the slabs due to the increasing load acting on the structure, thus the structure was still safe to use.

At four step model analysis there are two model choice must be known, a vehicle choice mode (mode choice), and the selection of the route (Route Choice). So far, the model developed in the world of transportation (RUM) has been based on economic theory, which emphasizes rationality in an election. Regret theory (RRM) developed a theory of voter behavior (choice behavior), where there is a state of uncertainty in it. Regret theory is used in various disciplines such as marketing, micro economy, psychology, management, and transportation. This study aims to demonstrate differences in the results of calculation of the analysis (RUM and RRM), in the case of choosing the type of vehicle, with Medan to Balige route, North Sumatera, where there are two alternative modes of vehicles, with three utilities in each of these alternatives. The results showed a significant difference in the results of the developed model.

Work activities on construction projects can experience disruptions caused by various things, one of the causes is the occurrence of work accidents. Identification and early analysis of potential hazards in each work packet, work methods, work activities, resources and environments in the WBS (Work Breakdown Structure) can prevent work accidents. Thus the need for WBS standardization is very important in presenting the assessment of risk, impact and frequency arising from workplace accidents. The purpose of this study was to develop a risk-based WBS standard for safety planning on dam construction. The results of this study are WBS standards, implementation methods, activities, potential hazard risks, safety planning using risk-based WBS standards, WBS dictionaries and WBS checklists on dam construction work, as an effort in preventing, reducing or eliminating the accident in dam construction work.

Nowadays, precast concrete structure system is one of the alternatives of construction methods that is mainly used in the construction projects. In its implementation, this method provides time and energy efficiencies and supports environment preservation. This method is also currently chosen as the main preference for bridge construction projects. However, along with the advantages that it provides, the construction works of precast concrete bridge is a complex project and should be planned and managed effectively. Also, full consideration of each aspect in the scope of this project, such as its defined methods, activities and resources in the construction works, which depend on the site and working condition, is essential. A standardized work breakdown structure (WBS) including the detailed WBS dictionary for its construction works for precast concrete bridge can provide in breaking down the abovementioned aspects and guide the constructor to execute the project. The WBS and its dictionary should be developed in the planning phase of the construction project. This paper explains the development of the WBS dictionary for the construction work of precast concrete bridge. The methodologies used are archive analysis, Delphi method and validated by experts. The WBS dictionary of the precast concrete bridge construction works consists of six (6) levels of WBS (including two supplementary levels), which itemize the work packages, work methods, activities, and resources.

The deep foundation at the Ketek Sikara-kara wharf is the function of foundation that distribute the load from the upper structure of the building to the soil on the bottom of building to the hard soil layer, without effecting shear failure and settlement, has a bearing capacity allowed. The function of Pile Driving Analyzer (PDA) at Parlimbungan Ketek Sikara-kara wharf to determine the bearing capacity of pile and also control to calendering test result, then this researched were tested the pile driving analyzer at 8 sections of pile from 84 sections of calendering pile (10% of the number of sections setting up). Obtained calendering results of lowering is equal to 0.60, 071, 045, 060, 053, 041, 065, 060 fulfilled the specification allowed ≤ 1 inch (2.54 cm). The largest value of pile calendering bearing capacity is 128.52 Ton and the smallest bearing capacity is 73.29 Ton more larger than the allowable pile bearing capacity is 60.9 Ton. Pile driving analyzer results of the largest bearing capacity is equal to TP - B12 Ru 177 Ton more larger than the bearing capacity of pile is allowed on planning is 60.9 Ton and the smallest is equal to TP - B22 Ru 111 Ton more larger than the bearing capacity of pile is allowed on planning is 60.9 Ton.

Various binders such as pozzolanic binder already known for its ability on enhancing the physical characteristic on concrete or soil stabilization. Pozzolanic reaction requires several primary factors to provide maximum improvement on physical characteristic. This research is aimed to identify the effect of the origin characteristics (physical and mineralogical) of pozzolanic binder on increasing the strength on engineering properties in soil improvement work. Two type of fly ashes are utilized in this study with different types of physical and mineralogical characteristic. Laser Granulometric test, and mineralogical test are realized to identify the characteristics of each fly ash utilized. To determine the effect of the binder addition (with different characteristics), several tests are performed such as unconfined compressive test, tensile strength test are realized to identify the effect of fly ash addition. The results show that binder with higher SiO₂, Fe₂O₃ and Al₂O₃ content produces higher strength.

Soil investigation working is a sub division of railway reactivation project of km 28 + 980 to 50 + 450 located in Binjai-Besitang, North Sumatera, Indonesia. Soil investigation was undertaken is sondir (cone penetration test / CPT) with the amount of 15 (fifteen) sections. Sondir test results to obtain soil parameters so that can be determined the type of compatible foundation and deepness so is obtained economics construction

Pile driving by using piling device of drop hammer or diesel hammer models can induce damage of the capital of column. Excessive tension caused by pile driving can induce dynamic load on the capital of column continuously. Structural damage is influenced by the exhausting piling materials. The analysis on pile driving by using GRLWEAP 2010 software produces tension and hammer performance during pile driving. Maximum tension in the used piles was by choosing the type and the weight of the used hammers. This experiment used square piles of 20 x 20 cm with concrete quality of K-450, the weight of hammer was 1.6 tons with pile compressive capacity of 20.352 mPa. From the analysis with GRLWEAP 2010 software, it was found that the maximum tension was 26.883 mPa with ram stroke of 3 meters. In this test, the tension capacity during pile driving increased with the reinforcement on the structure which received tension during pile driving so that the pile capacity increased and reduced damages during pile driving. The reinforcement on the capital of column was temporary, only during the pile driving. The reinforcement on the capital of column was done by using Carbon Fiber Reinforced Polymers (CFRP), the type of sika®wrap 231C. The experiment of pile driving was done by conducting pile monitoring, using Pile Driving Analyzer (PDA) Test in order to find out the hammer performance and observing the capacity of piles without using any reinforcement and with using reinforcement. The structural behavior without using the reinforcement of capital of column indicated pile damage with ram stroke of 1.20 m; with the reinforcement of sika®wrap 1 layer the stroke was 1.90 m, and the reinforcement of sika®wrap 2 layers ram stroke was 2.80 m. The increase in the structural capacity toward tension during the pile driving with 1 layer of FRP was14.720% and with 2 layers of FRP was 51,776 %.

Construction of Dam region irrigation Bajayu Serdang Bedagai is one of public infrastructur in Tebing Tinggi city, as the most important agricultural sector. Dam is the main building infrastructure in irrigation that serves to raise the air to flow to the planned irrigation area. With this effort can be arranged or managed, so that agricultural productivity can be improved. Serdang Bedagai Regency (Sergai) is one of the rice granaries in North Sumatra Province (North Sumatra). To maintain and improve the productivity of agricultural land in the area requires adequate irrigation air. This research was conducted to find out the right time, to analyze the financial and economic feasibilty of the dam construction of Bajayu irrigation area with indicators of NPV, IRR, and BCR as well. Sensitivity analysis due to cost changes. This research is done by collecting basic data of research conducted in field then data from field processed into form of systematic calculation. Next analyze the primary and secondary data generated from. After that a formulation that will be used derived from literature study then performed data analysis. The results of the data analysis will be used as the basis for making conclusions so that suggestions will emerge. Optimal handling is estimated to be 10 years, so in that time period it gradually increase to the 13th year and will remain from year 13 to the next. From the financial calculation of Bajayu Irrigation Area obtained NPV = IDR 1.778.603.070.507,62, IRR = 27%, BCR = 4.6. And from the economic calculation of Bajayu irrigation Area obtained NPV = IDR 1.235.038.404.979,95, IRR = 32%, BCR = 6.92. From the calculation of the sensitivity analysis for the change of cost (cost) and the benefit of ±5% and ±10% for financial and economic analysis shows the project plan is still very feasible.

The performance of public transport in some developing cities such as Medanis getting worse resulting in heavy traffic burden, because the society prefers to use private vehicles. This is inversely proportional to the rapid development of public transport technology. For example, Monorail, Bus Rapid Transit (BRT), Commuter Line, Light Rail Transit and others. Mebidang area currently has a bus-based mass transit system called BRT Trans MEBIDANG. Based on the initial hypothesis, this system is not functioning optimally because of the lack of service network. Currently BRT Trans MEBIDANG system only serves on two corridors. Firstly, in this study, a new service network is required. The new service network is tested through questionnaires to respondents to know their preferences. The analysis using the binomial logit model showing the respondent preference for the use of BRT Trans MEBIDANG system. With 86.747% (2,175 respondents) if the difference in travel costs is IDR 3.000. Furthermore, 96,395% (2,410 respondents) if the difference of waiting time is 7 (seven) minutes and last is 62,547% (1,564 respondents) if the difference of travel time is 20 (twenty) minutes.

Various binders such as pozzolanic binder fly ash, Silica Fume already known for its ability on enhancing the physical characteristic on concrete or soil stabilization. Pozzolanic reaction requires several primary factors to provide maximum improvement on physical characteristic. CaO is one of the most important factors that capable to enhance the strength gained. This research is aimed to identify the quantity of the available amount of CaO content in the binders used, and the effect of the available amount on increasing the physical characteristic of the concrete. In this study two type of pozzolanic binders such as Fly Ash are used, to identify the amount of available CaO content, the researcher used Chapelle Test. The engineering test such as unconfined compressive strength is realized to determine the effect of amount of CaO. The results show that binder with higher amount CaO increase the strength development.

A traffic simulation model is an effective approach tool for analyzing traffic operations. It can produce relatively close to real-world output. This study aims to determine the effect of motorcycle proportion on the length of the queue which is then modeled using Vissim Software. Data obtained from the recording handycam are volume and type of vehicle. The data shows that the largest proportion of motorcycles is as follows: Pulau Pinang road = 67.6%, Ahmad Yani road = 73.9%, Setia Budi (north) road = 69.7%, Setia Budi (south) = 71.1%. Based on the survey and Vissim simulation the maximum queue length at Pulau Pinang road is 192 m and 267.14 m. Ahmad Yani roads are 290 m and 375.2 m, Setia Budi (north) road are 233 m and 489,5 m, Setia Budi (south) road are 230 m and 477.9 m. It is clear that there is a significant difference between the simulation and the real situation for the queue length results. The results also concluded that there is no significant correlation between motorcycle proportion and Queue length on the real situation

Indonesia has a strong commitment on reduction its Green House Gases (GHGs) emission. The energy sector (all the activities that burn fossil fuel) contributes significant amount of GHGs emission. In order to meet the target of emission reduction in the energy sector the use of renewable energy resource such as solar energy is being enhanced. One of the potential applications is solar water heater. Since the last several years, our research group is developing solar water heater that suit for Indonesian climate. The objective of this paper is to examine the present condition of our achievement in developing the solar water heater. Literature reviews are presented, experimental and numerical results and challenges are discussed, and future works are suggested.

This study was conducted to design a heat exchanger double pipe counter flow as a condenser to produce hot water that can be used for various purpose like a warm bath. Hot fluid flows in copper with cold fluid flowing in the annulus. The hot fluid used is R-22 while the cold fluid used is water. This pipe double heat exchanger is measuring 112.04 cm in length by 29 cm in width and 20.3 cm in height. Inside of pipe using copper with diameter ¼ inch. And total length of the copper pipe 18.915 m. While on the annular pipe using PVC pipe with ½ inch size. The total length of the annulus pipe is 16.128 m. In addition, heat exchanger is used to determined heat released by the condenser, coefficient of performance (COP) of vapor compression cycle, efficiency vapor compression cycle and temperature of the condenser-generated hot water.

This study aims to obtain the flexural strength of the material of automobile spoiler products obtained from the free market that are made of plastic materials. The values of the strengths obtained are used as comparative data for the development of automobile spoiler products based on composite materials of epoxy rattan fibers. Flexural strength testing refers to ASTM D 730-03. Based on the research results, the flexural strength of spoiler product from plastic material is 55.72 ± 3.53 MPa, while the flexural strength of spoiler product made of epoxy rattan fiber composite material is 45.37 ± 0.89 MPa. The difference between the two flexural strength results is 8.9%. The results of SEM testing on the spoiler material show that the material has a little void due to the manufacturing process that can reduce the power of the spoiler product. Voids also occur in composite material of epoxy rattan fibers due to manufacturing imperfections. Based on the data of the flexural strengths obtained, it can be concluded that the epoxy rattan fiber composite material can potentially replace the plastic material in the manufacturing of spoiler products. The results of this study can be used as a reference in the development of car spoiler products.

Directly discharged hot water will not be a bad effect on the air. In this research to make a tool of heat designer that utilize heat energy from waste of hot air of fertilizer factory which function to heat air and will be used as hot water in residential bathing place of fertilizer factory employee. By utilizing the heat energy from the hot water waste then the temperature of this hot water will also fall and then can enter the river without endangering the ecosystem in the river. In summary, there is a 1.64 m long heat exchanger, 0.48 m width and 2.1 m height. The total length of the pipe in the heat exchanger is 2.7 m in diameter 13 mm, and the shell is 1.35 m long and 70mm in diameter, volume on the tank this exchanger is 27 Liters.

In this study a heat exchanger was manufactured and utilised as paddy dryer. Diesel engine exhaust gas was used to heat the air and supplied to the heat exchanger. A shell and multi tube helical coil heat exchanger was employed with shell length and diameter of 1,050 mm and 152.4 mm, respectively. Furthermore, a tube with twenty coil and 3,250 mm length was attached inside the shell where coil diameter and helical coil number are 58.8 mm and 4, correspondingly. Besides, Heat source was generated from the diesel engine exhaust gas. The engine can generate 54 kW of power and maximum speed of 3600 rpm. The aim of this research is to analyse the paddy drying time using rotary type dryer equipped with heat exchanger. This study based on experimental work, the data retrieval procedure is the way in which to obtain the necessary data to be analyzed, where the procedure is initially the water is loaded into the tank and the valves are all open, then the pump switch is switched on so that water flows in the drains of the appliance heat exchanger and then diesel engine turned on so that hot gas flow in the gas line. This is done to dispose of the air contained in the heat exchanger, let it last for a while until the exhaust gas temperature goes into the heat exchanger in steady state. The result revealed that in order to obtain 14% of paddy moisture content, it took 8 hr and 33 minutes of drying time at 46.7 °C of air temperature with the rate of air mass flow of 0,057383 kg/s. Whereas, it was 8 hr and 37 minutes long to get the same moisture content when the air temperature and air mass flow were maintained at 70.4 °C and 0,082788 kg/s, accordingly. The energy needed to dry the paddy at 46.7 °C was 19374.89 kJ. In contrast, it was required 18932.03 kJ of energy at 70.4 °C. If it is seen from the explanation then the main conclusions of this research that by using this rotary type drying tool the drying process can be done and can save cost and time, besides that also this finding provide recommendation information related to the utilization of alternative energy for drying.

Low cost green car (LCGC) is one of the latest breakthroughs conducted by the automotive industry, especially in Indonesia. This eco-friendly concept car provides an alternative choice that better suits the needs of consumers in Indonesia. Expert System using Forward Chaining method is intended to predict LCGC car as needed. Data were collected through observations and interviews conducted through sales and auto mechanics or experts who knew more about market conditions and community needs. The results achieved is to design an expert system applications predict LCGC cars according to consumer desires based on the type of transmission, color and price. In addition in this expert system application also displays video trailer car category LCGC to facilitate consumers to make choices. Long-term objectives in the application can be complemented with information on the advantages and disadvantages of LCGC cars and the spread of workshops or official or unofficial dealerships so that the community finds it helpful. The conclusion of this research is Forward Chaining method can be used to perform a search to get predicted LCGC car prediction results.

Briquetting of ground hazelnut husks and sunflower stalks was examined to determine the energy requirement, deformation, thickness and hardness. Four compression forces from 100, 200, 300 to 400 kN and a single speed of 5 mm/min were applied using the universal compression-testing equipment and a vessel diameter of 60 mm with a plunger. The results show that compression force had a significant effect on numerical energy, thickness and hardness of the densified briquettes of ground hazelnut husks and sunflower stalks. Deformation values of the densified briquettes were not significant in relation to the force effect. The densified ground sunflower stalks required lower energy compared to densified ground hazelnut husks. However, in terms of hardness and/or strength and durability, ground hazelnut husks briquettes could be suitable for energy use.

In this present study, a combination of compression forces and speeds were examined for the undulation or serration behaviour of bulk rapeseeds and sunflower seeds using the universal compression device and a pressing vessel of diameter 60 mm with a plunger. For bulk rapeseeds, the forces were from 80, 100 and 120 kN while sunflower seeds, the forces were from 100, 150 and 200 kN. The speed ranged from 5 to50 mm min⁻¹. The study revealed that at force 80 kN in relation to the different speeds, the force and deformation curves of rapeseeds were without the serration effect. This was similar to sunflower seeds at forces 100 and 150 kN. The undulation effect for rapeseed was noticed at forces 100 and 120 kN at speeds between 25 and 50 mm min⁻¹. On the other hand, a smooth curve characteristic was seen for sunflower seeds at force 200 kN and speeds of 5 and 10 mm min⁻¹ respectively. At a speed of 15mm min⁻¹, the serration effect was mild. From speeds 20 to 50 mm min⁻¹, the undulation effect was pronounced. In conclusion, increasing the compression force sand speeds demonstrated the undulation behaviour of both sunflower and rape bulk oilseeds. Energy efficiency for maximum oil recovery is realised under the area of the smooth curve behaviour.

Automation design of material transfer on the shearing machine is the process of designing a series of tools or machines with a single system to facilitate the process of transfer of the initial material to come separately one by one into the table of the shearing machine. Tools are designed to run automatically for the purpose of work efficiency. In the design process required various calculations at each stage of the system group. This is done to avoid the failure of a design whether it is major or minor. The design starts from the forklift comes laying the material along with the pallet on the conveyor waiting, then the material along with the pallet walks into the first stage conveyor. At this stage there is a hydraulic component that is designed to have its tip roller and tilt angle, so when the hydraulic working material will be separated by the pallet and slid down into the second stage conveyor. In the second stage conveyor, the material stack will be stopped by the stopper, the stack of materials will be separated one by one to the third stage of the conveyor connected to the set of tables. Separation is done by claws that are moved by a ball screw. Components of the claws and stopper can go up and down following the thickness of the sheet material. After the sheet is released from the third stage conveyor, there will be an arm with a pneumatic-driven tip clamp and ball screw to push it to the machine table and pull on the remaining cutting process. At the end cutting the arm will push the final sheet through the engine blade. The design of material transfer automation on the shearing machine is still in the early stages of research in the field of material transfer. Result before designing are, the diameter of shaft of the buffer for safety factor is 20 mm, Hydraulic tilt is formed by angle α = 5,85°, Designing four hydraulics with 2-inch piston diameter, it is necessary to prepare a power pack to support the hydraulic system of at least 36 bar.

Solid lubricants have an essential role in brake lining composite. They can reduce wear that occurs either on the brake lining composite or the contact surface. In this study, the effect of solid lubricants (MoS₂ and graphite) on brake lining composite at various sliding speeds and contact pressure has been investigated. Three brake lining composites were made with the same formulation except for the addition of the solid lubricants, all of which have 15% graphite, 12% graphite + 3% MoS₂, and 9% graphite + 6% MoS₂. The coefficient of friction test with various contact pressure and sliding speed was conducted by using a pin on disc tribometer. The result showed that coefficient of friction and specific wear was strongly influenced by the solid lubricant. Compared with graphite, MoS₂ had a better lubrication performance. An increase in MoS₂ content decreased the coefficient of friction either on contact pressure or sliding speed variation. MoS₂ also reduced the specific wear as well as the temperature rise in the disc.

In this study, the effect of welding parameter such as rotational speed on the mechanical properties and microstructure of friction stir spot welded Al 5052 and SS400 sheet have been investigated. The rotation speed of 1250, 1600, 2000 rpm and the dwell time of 10, were applied to fabricate the friction stir spot welded joint. The microstructure of the joint was observed using scanning electron microscope (SEM). The tensile shear load was measured using by universal testing machine. Base on the microstructure observation showed that the thickness of IMC increases due to the increase of rotational speed. The Maximum thickness of IMCs reached 7.15 µm at 2000 rpm. The result of the tensile shear test showed that the rotational speed is affecting the mechanical properties. The increase of tool rotation speed from 1250 up to 1600 rpm caused the increase of tensile shear load, however further increase up to at 2000 rpm resulted in the decrease of the shear tensile load. The highest shear tensile load reaches 2810.07 N at 1600 rpm.

Performance of prototype portable bio-adsorber has been evaluated. This tool is designed to purify the waste of cooking oil by passing the cooking oil into the adsorber column on the prototype portable bio-adsorber, which has been filled with bagasse charcoal bio-adsorbent. Finally the waste cooking oil that has been through the purification process will be accommodated in tub products and analyzed levels of free fatty acids before and after the purification process takes place to know the efficiency of the prototype portable bio-adsorber. The result of this activity is a prototype portable bio-adsorber with 70 cm pipe height and 3 liters capacity of feed to operate in batch and can accommodate 800 gram of baggase charcoal as bio-adsorbent with the efficiency for reduce free fatty acid is 43% and also can reduce the color of cooking oil, so the color of waste cooking oil also becomes more clean but the results obtained are not maximized, therefore it needs a continuous process for the process of purifying the cooking oil in order to increase the efficiency of the prototype portable bio-adsorber.

The primary objective of this article was to obtain the performance of a solar adsorption refrigeration system using a mixtures adsorbent. The experiments were carried out under real solar irradiance conditions from 08.00 WIB until 08.00 WIB the next day local time in Medan city in November 2017 during seven cycles. Both coefficients of performance (COP) and specific cooling power (SCP) were calculated according to experimental data to analyze the operation of the refrigerator. Theoretical calculations show that the COP values to be in the range 0.0770-0.1003 and the SCP values 31.895-34.103 W/kg. The experimental result obtained that the cooling effect of the evaporator temperature of 4.16°C when the daily global irradiance lies between 11.245-17.156 MJ/m².

This research focuses on Earth-Air Heat Exchanger (EAHE ) that reduces the energy consumption of the air conditioner and analyzes the performance of the EAHE device by calculating the fluid dynamics modelling and validated against experimental observation. The used simulating are transient, incompressible, turbulent and 3-dimensional CFD. The simulation condition was limited to fluid flow only with a variation of 3 m/s, 2 m/s and 27m length of an air exchanger. The results of the simulation are pressure display, temperature, and velocitydeploymenton the passage of EAHE, and the comparison with the experimental results. The decrease in air velocity (V_air) can cause the out temperature (T_out), the coefficient of performance (COP) and the value of the effectiveness (ε) for EAHE will decrease and inversely proportional to the NTU will increase. The average air temperature out of the 3D simulation result using Ansys 14.5 Software was 26.6°C for air velocity inlet 3 m/s and 26.5°C for 2 m/s, while the experimental result was 27.5°C for 3 m/sand 27.4°C of 2 m/s. The highest deviation between the simulation and the experimental result were 3.452% for 3 m/s, and the lowest was 3.048% for 2 m/s.

Quality function deployment (QFD) begins when we want to identify the consumer needs expressed in qualitative characteristics. QFD is a matrix (house of quality matrix) that connects what the customer wants and how a product is copied, produced to meet customer needs. Facilities that are not ergonomic makes workers uncomfortable and result in pain complaints. Work facility improvements were made by applying the QFD methodology to minimize occupational pain complaints. The result of the research was found the design of new work facility with high dimension of the chair foot 45.14 cm, the length of the holder 45.59 cm, the width of the holder 32.51 cm, the height of the back of 58.26 cm, the width of the backrest 41.66 cm and the height of machine foot 68.41 cm.

Biomechanics is an important factor in ergonomics. Therefore, in this research will be applied biomechanical calculation. This research is conducted in the manufacturing industry engaged in the processing of oil palm. As for the processing process has several stages. The core of this research is to examine the work done by the operator. Where often occur complaints on the insertion of fresh fruit bunches. Common complaints are fatigue of joints and muscles caused by many activities that occur continuously in the sorting. In this study, biomechanical measurements were made, where the measurements consisted of permitted weight limits, lifting index, and the maximum load limit that may be removed. This is considered important because so far the operators and the industry is not aware of it. They do so unwittingly impose body condition. Causing musculoskeletal disorders and other risks that may occur. Based on the Recommended weight and lose weight measurements of the fresh fruit bunches workers who did not meet the fraction it can be concluded that lifting the fresh fruit bunches that did not meet the fraction contained the risk of musculoskeletal disorders and based on the measurement of maximum permissible limit obtained the AL <Fc <MPL, the sorting of fresh fruit bunches that do not meet the fraction should be careful.

This is where the research company which produces flour. The actual conditions on the production floor are found a lot of manual activity one is packing. Physical workload examined in order to determine the energy consumption and% CVL operator. Based on the calculation of the workload is known that the operator has a very heavy percentage category, namely 47.82%, for the Measurement of energy carriers showed that 80% of energy consumption in the category of heavy operator is 401.95 Kcals / hour based on% CVL operator, operators are in category required immediate action. Based on the calculations made through this research turns out the workload at a packing station is classified by weight category, causing significant fatigue for the operator where the number of carrier pulse exceeds normal limits. Energy needs necessary operator still not been met, where the category workload largely classified as severe. The result shown that timing of rest required by each operator is not enough.

Speed up in vacuum desalination system means many things that are in desperate need of development especially energy transfer. Therefore, in this experiment, a pump is used to transfer the energy from the solar collector into the evaporator including the forced convection heat transfer. The water fluid inside the solar collector is heated by sunlight and then pumped into the evaporator to evaporate seawater. It is done to support the performance of the condenser which turns steam into clean water. It is reported that pump performance for a total head loss value is 2.67 m and for pump head is 2.82 m. By generating pump axle power of 28.73 W, thus the resulted motor power was 33.03 W. With total existing energy for 13 MJ/m² the electric current generated by solar cell during experiment is 2.6 A in average from 08.00 A.M until 16.00 P.M with speed water average of 3.1 m/s. It is due to the effect of the sun intensity if the sun intensity is high speed of the pump is also high since it uses a photovoltaic 100 WP therefore it affects the electric current received by the pump.

Metal machining processes require primarily cutting tool materials with high hardness, high resistance to the abrasive wear and thermal stability. The development of cutting tool materials results in advanced tool materials such are primarily ceramics, cubic boron nitride and sintered carbides which are considered to have the ability to cut hard materials. As a finishing process, the machined surface of the final product needs to control the surface quality. The quality of machined surface can be determined by properties such as surface roughness, hardness variations, micro-structural changes, residual stresses, etc. These properties belong to the surface integrity of the work piece material. The surface integrity affects significantly the mechanical properties of the parts such as fatigue limit, stress-corrosion resistance, dimensional stability, etc. This paper presents an experimental study to analyze the evolution of residual stresses in relation to the different parameter of machining. For precision milling of hardened steel, parameters are cutting speed and feed rate with a constant depth of cut. Two different cutting tool materials were used in this study, ceramic and cubic boron nitride. The results show that residual stresses near the machined surface of hardened steel are suitable for compressive stress.

Study of vibration characteristics of an induction motor that is not controlled and is not closely monitored and regularly adversely affects the vibration and the impact on comfort and engine life. This study aims to investigate the characteristics of vibration on electric-driven generator steam turbine at PT. Perkebunan Nusantara III (PTPN III) Rambutan Tebing Tinggi. The object of research is protected steam turbine engine palm oil processing factory company PTPN III Rambutan Tebing Tinggi. The results of this study show from both the point of measurement at engine speed rpm compared 4800, 4900, and 5000 obtain that the vibration velocity is highest at 120 seconds, 5000 rpm rotation vertical direction at the point G1. ISO 10816-3 standard for velocity on the highest vibration response measurements at two measurement points on the position of the engine cradle generator of 0.650 x 10-6 m/s Zone A is green, the vibration of the engine is very good and below the allowable vibration.

Elimination of echoto improve sound quality is essential term of comfortable function room. This study aims to investigate the enhancing of acoustic quality of a meeting room using eco-absorber panel based sugar palm fiber in UNS Inn Hotel, Surakarta, Indonesia. The panel was made from albizzia wood with sugar palm fiber as acoustic fill covered by sponge and Regency fabric. The reverberation time calculated with theoritical method was to validate thatmeasured with in situ test. The testing was performed using an impulse method by recording handclap sound, and the data was processed using MATLAB software to determine the reverberation time value. The testing of sound pressure level and sound distribution were conducted with two loud speakers placed in front ofthe room for frequency of 250 Hz. The sound pressure was measured at each measurement point using sound level meter. The absorber panels were installed on the back wall of the room varied in 100%, 75%, 50% and 0% of the wall sectional area. The result shows that the increase of installed absorber panels decreases the reverberation time value and it has good correlation with theoritical calculation. According to the test results of sound pressure level and sound distribution, the lowest reverberation time is achieved for 100% of installed absorber panel. The reduction of sound pressure level and sound distribution are up to 18.3 dB and 40-60 dB, respectively.

Continuous process for biodiesel production using homogeneous catalysts finds many constraints. Heterogeneous catalysts are the solution for the production of continuous biodiesel. One of the heterogeneous catalysts is zeolite/KIO₃. Determination of operating conditions for heterogeneous catalysts, especiallyzeolite/KIO₃ is required to obtain appropriate process conditions in order to the continuous system. The Taguchi method is one of experimental design that focuses on the variable approach to product quality improvement by control operation condition. Taguchi method is designed using 4 independent variables with 2 levels (4x2), which are temperature, mole ratio, time reaction and heterogeneous catalyst ratio. The Taguchi method can provide an analysis of the influence of each process variable significantly. This study aims to determine optimal operating conditions for the production of biodiesel with the KIO₃ heterogeneous catalyst. Biodiesel is synthesized by esterification (pre-treatment) and transesterification following the Taguchi method. The source of triglyceride is crude palm oil while the alkyl source comes from methanol. Based on the result of analysis Taguchi method known that all process variables have an effect to transesterification reaction. But, variable temperature and reactant mole ratio give the most significant influence and show the interaction with p-value value 0.000 (temperature) and p-value 0.001(reactant mole ratio).Thus, for the production of biodiesel using the KIO₃ heterogeneous catalyst obtained optimal operation conditions at temperature 65°C, mole ratio 1:6, time reaction 120 minutes and heterogeneous catalyst ratio at 5% (w/w). ANOVA gave result decided to reject Ho, and decided the reaction model influence by the variable process.

In this study the fluid flow and velocity distribution in a solar drying box which is used to dry coffee beans are studied numerically. The solar box receives the hot air from flat-plate collector. The hot air is flowed by using an electric fan which is powered by a photovoltaic. The objective of this study is to explore the temperature and velocity distributions in the box. The dimension of the drying box is 100 cm × 90 cm × 50 cm. Several experimental are carried out. The experimental results are used as boundary value in the numerical simulation. The commercial code CFD is used to perform the analysis. The results show that the temperature of the hot air entering the solar drying box varies from 29.29°C (at 9.00 AM) to 59.98°C (at 14.00 PM). By using these data, the numerical simulations are carried out. The temperature and velocity distributions are plotted and discussed. It is recommended to use the results to design an optimum solar drying box.

Heat Exchanger is an important equipment in engineering application. In order to improve the efficiency of a heat exchanger many modifications can be promoted such as baffles. The objective of the present study is to explore the effect of baffle spacing to the effectiveness of a heat exchanger. A U-tube type of shell and tube heat exchanger has been analysed numerically using a commercial code of computational fluid dynamic. The baffle spacing is varied from 40 mm, 50 mm and 60 mm. The temperature distribution, path line and vector velocity are plotted and discussed. The temperature effectiveness and the heat transfer rate of the heat exchanger is then examined. The results show that the smaller baffle spacing results in higher thermal effectiveness.

To increase the performance of Air conditioning it is needed to propose any modifications. One of the potential modification is installing internal heat exchanger which is typically an annular pipe. The objective of this study is to explore fluid flow and heat transfer characteristics of Refrigerant R32 in an annular pipe heat exchanger. The fluids flow in the inner annulus is hot fluid and the cold-water flows in the outer annulus. In this study, CFD model is developed which is solved using ANSYS Fluent and validated with the previous available data, the dimension of annulus internal heat exchanger for heat fluid diameter of 6.35 mm. The working pressure and temperature are 290 psi and 32.5°C, respectively. While the cold fluid flows at annular with outer diameter of 9.525 mm and working pressure and temperature are 90 psi and -8°C, respectively. In addition, the external diameter is 19.05 mm, the direction of the fluidsisa counter flow between hot and cold fluids for the numerical simulation. The fluid flow characteristics are plotted and the heat transfer rates are examined.

Vapour-compression cycle is the most widely used refrigeration cycles for Air-Conditioning (AC) units. The system consumes a significant amount of the energy. Thus, any modification to improve the energy efficiency is extremely needed. One of the well-known modification is multistage VC cycles. The objective of this study is to search the optimum high pressure based on environmental temperature of air condition. The single-stage cycle is analysed using for three different refrigerants (R32, R22 and R134a.). Pressure was varied based on ambient temperature. The governing equations and the boundary conditions are solved using Aspen Plus software. COP, refrigeration effect (RE), and compressor power as optimum temperature are plotted. The results show that there exists an optimum temperature for optimum cycle.

Utilization of photovoltaic has been widely used in order to reduce dependency on unrenewable natural resources. In order to maximize solar radiation as down to earth surface, the use of photovoltaic needs to be varied. These varied Photovoltaics are to measure each of the efficiency of the work performance and charging rate stored into batteries. Typical Photovoltaic that is used in this measurement is 3 Photovoltaics with 50 Watt Peak in variation angle of 0⁰, 5⁰, Solar Tracker based Real-Time Clock. The efficiency of work performance of each varied angle 0⁰, 5⁰, Solar Tracker are 13.21 %, 14.1 %, dan 15,26 %, meanwhile the results of charging rate of each batteries within 6 hours conduct 17,42%, 21,71%, 25,14 %. Work performance can be improved further with varies Solar Tracker base LDR sensor to be more accurate.

In this study a flat plate type solar collector with fin is studied numerically. The fins are installed to the plate absorber to increase the thermal efficiency of the collector. The objective of this paper is to explore the temperature and velocity distribution in the solar collector. In addition, the rate of the heat transfer from the plate absorber to the tube is examined. The governing equations are developed based on mass conservation, momentum equation and energy conservation. The developed governing equations are solved numerically using commercial computational fluid dynamic code. Pressure distributions, temperature distributions, and velocity distributions are plotted and discussed. The heat transfer rate from the plat absorber to the tube is estimated. Effect of the fins to the heat transfer rate is examined. The results showed that there is no significant effect of installing fins to the performance of the solar collector. It is suggested to use the present result in designing an optimum solar collector.

Indonesia has a strong commitment on increasing renewable energy resource utilization to produce electricity. One of the potential renewable energy resources is hydropower. In Indonesia, the hydropower is divided into small scale hydropower (less than or equal to 10 MW) and hydropower (more than 10 MW). In order to enhance the utilization of small scale hydropower several financial and regulation supports have been released. In this study the growth of small scale independent power producer has been investigated. The study focused in Sumatera Utara province which is known as the province with big potency of small scale hydropower and the electricity infrastructure is quite developed. The results reveal that there are 115 locations of small scale hydropower projects had been developing in the province. The total capacity is 930.3 MW. However, only seven of the projects (6%) have been in operation stage and produce electricity to the grid. Almost all of the projects have experienced on over design budget and time. There are several technical and social barriers that affect the growth. Technical barriers include low quality of pre and full feasibility studies, low quality of detailed engineering design (DED), limited access to relevant expertise, tend to underestimate the technical complexity of developing a small-scale hydropower. Social barriers include the environmental issue, land acquisition, and electricity needs of local people.

The vibrations that arise in the axis of the wind turbine is a phenomenon that results from the unstable wind velocity coming from the angle of the wind attacked by the blade of the wind turbine itself. Vibration is widely used as a tool to analyze both machines with rotation and translational motion. Knowledge of vibration and the resulting data is very important for maintenance and repair analysis. This understanding can help the technician to reduce downtime and can increase profits both in terms of production and from longer wind turbine life. Vibrations arising from cyclic forces through existing machine elements, where they interact with each other and energy is amplified through the structure in the form of vibration. The effects of vibration are the occurrence of noise, the decrease in performance and performance of wind turbines and can damage components in wind turbines especially on shafts and bearings. In this study varied angle blade (blade / rotor) wind turbine to the shaft as well as variations in the coming wind speed. With the variation can be observed and known behavior of vibration that occurs by measuring by using vibration vibrometer VQ-400-A OMETRON connected with Labjack U3-LV forwarded to the PC in the form of a digital power voltage to an analog voltage. This model measures vibration in the horizontal or x-axis direction where the laser focus point on the rotating wind turbine shaft. To display the measurement results are used labjack connected to the laptop PC. This research resulted that for wind speeds between 3- 4.5 m/s which has the smallest deviation using 30º blade angle to minimize the vibration that is between 0.2353425 mm to 0.356839 mm. Based on the calculation of critical frequency occurs if the frequency of turbine rotation up to the frequency of 9.464226 Hz and the simulation using ANSYS software apply frequency of 4.1854 Hz.

Cost is the price used or sacrificed in order to earn revenue and will be used as income deduction. At the beginning of the initial cost accounting is only intended for the determination of the cost of products or services produced, but with the increasing importance of non-production costs, namely marketing costs and general administration, cost accounting is currently intended to provide cost information for both production cost management and non-production costs. Activity-Based Costing (ABC) is a system that is a cost calculation approach that focuses on activity as a fundamental cost object. The ABC system uses the cost of such activities as a basis for allocating costs to other cost objects such as products, services or customers. In the cost system of activity based costing, the product is defined as goods or services that the business is trying to sell, including health services, insurance, bank loans, consulting services, gasoline, cinema, bread, and others. All of the above products are generated through the company's activities and these activities consume resources.

There is a huge potential of turmeric to be processed into various kinds of medicines or food products as there are still many people consuming traditional medicines and beverages for their health. Thisleads to the need of a clean raw turmeric processing, in spite of the fact that turmeric commodity grown in the high lands. The process of direct turmeric drying can not be maximal because of the low solar intensity caused by cloudy weather. If the drying process continues to constantly produce 12% water level, the turmeric medium will be damaged due to fungus arise on the surface of turmeric influenced by high humidity factor. Therefore a closed turmeric dryer with LPG fuel at a low cost is made. Using ST 37 material for the construction frame, while the inner cover uses stainless steel, and for the outside cover uses hot rolled steel sheet material. In addition, the dryer used can be controlled by air velocity and temperature in the drying cabinet and equipped with transparent glass to see the physical state of the turmeric inside. Obtained temperature during experiment is 50-550C in average with drying duration of 60 minutes with 0,15 m / s air speed and the water level obtained is 12% with the efficiency degree equal to 59%.

Hardness is a material physical property that needs to be known to apply on steel HRPS. Each treatment given to the HRPS steel can change its physical properties, since the treatment given by the microstructure on steel HRPS will change. This study is carried out by means of a 55 mm and 60 mm bended HRPS steel, which then applied the quench and temper heat. The next step is by analyzing the hardness of a material at each point using Hardness Vickers tester. The hardness value at each point with distance per 1mm is started from the curve point due to bending. Hardness is identified from the nature of the changes indicated by the hardness test data. The results show that, there is an increasing hardness level resulted from the heating level. The quench-temper heat treatment process on the HRPS steel has a clear effect on structural changes and mechanical properties of the HRPS steel. In addition, bending treatment with different angles affects the hardness value on the steel HRPS.

Mobile devices are becoming an indispensable part of daily lives. This system has been developed interactive android application to assist and provide the support helps people such as blind and other physically limited people who face. They will be done for outgoing calling to his family and also the area around them. Speech recognition is technology that uses desired equipment and a service which can be controlled through voice of the android smart phone. An Artificial Neural Network (ANN) is an information processing paradigm that is inspired by the way biological nervous systems, such as the brain, process information. The device proposed here is an interactive android platform, which is capable of recognizing spoken words. We propose to developed interactive android application and also added some features which are currently available in android based smartphones such as attending for a line calling feature and out-going calling feature, over the voice commands which can run on the tablet or any android based phone. Speech recognition have a data set to translate between users' descriptions and the labels in the database, which has entries on the speech recognition (sounds and patterns) that make up the sound.

Machine learning of seismic waveform is core component to realize the characteristics of signal. The nuclear explosion is Wavelet signal processing is broadly used for analysis of real time seismic signal. The numerous wavelet filters are developed by spectral synthesis using machine learning python to realize the signal characteristics. Our paper aims to solve and evaluating the frequencies-energy characteristic of nuclear explosion. The wavelet method by Continuous Wavelet Transform (CWT) is clearly to identify of amplitudes and frequency-energy from component of nuclear test performed by the North Korea that occurred on September 03, 2017. Finally, by machine learning python with Morlet wavelet allows good time resolution for identified and performed of Broadband Seismic from Comprehensive Nuclear-Test Ban Treaty Organization (CTBTO) in Indonesia.

Wavelet signal processing is broadly used for analysis of real time seismic signal. The numerous wavelet filters are developed by spectral synthesis using machine learning python to realize the signal characteristics. Our paper aims to solve and evaluating the frequencies-energy characteristic of earthquake. The wavelet method by Continuous Wavelet Transform (CWT) is able to clearly and simultaneously of amplitudes and frequency-energy from component between the seismogram which seismic sensor broadband recorded in the January 16, 2017 in Medan, North Sumatra. Finally, from machine learning python with morlet wavelet allows good time resolution for high frequencies, and good frequency resolution for low frequencies.

Harmonics in distribution networks cause power quality problems that increase heat on transformer. This heat influence transformer performance. Distribution transformer condition monitoring avoids further consequences by continuously monitoring transformer performances. This paper proposes condition monitoring schema for distribution transformer within PLN network as the transformer capacity is small but its number is a lot. Harmonics, load and temperature are analysed to extract condition monitoring tendencyfor period of three months. Preliminary study shows that the proposed method suits the limited available data.

Wireless is not only for communication, but also for power transfer. This paper presented wireless power transfer prototype by using a Royer oscillator. From the experiment, it is obtained that At the transmitter, transmitted power increases exponentially to number of capacitors, so does the frequency. At the receiver, received power and frequency increase if number of capacitor in transmitted added. Maximum received power is 0.444 W and efficiency 96.5% at distance 7 cm.

Solar panel operation depends on sunlight intensity where solar panels are placed. This study aims to design a real-time monitoring device for measuring the performance of solar panels. From the assessment sample, the designed device is successfully measure the parameters of solar panel characteristics and environmental parameters. The designed monitoring system is also able to identify the effect of wind speed and humidity.

The scoreboard is designed and made for a universal use that can be used in matches in some sports such as basketball, futsal, ping pong, badminton, and others. The scoreboard is designed and made based on the needs of several sports in the Student Activity Unit at HKBP Nommensen University which can be easily moved. Scores displayed on the scoreboard is not only the result of the game but also displayed time in the countdown. This scoreboard can be operated by using a cable and can also without using a cable by using a mobile phone through communication using bluetooth. This scoreboard is based on a microcontroller and uses backup power through rechargeable batteries that can be automatically charged. In trials in several games, this tool works well with a few drawbacks in case of a match that takes more than 100 minutes because the time display can only display a maximum time of 99 minutes.

In this paper, design of a digital controller based on model-following system is proposed for single-input-single-output (SISO) system. The controller needs a design method which could easily be done so the plant responses will follow the model responses. The digital controller could be designed for use when the orders of the model and the plant are same. As a result, a sample of simulation was showed that the proposed method was stable to plant parameter variations.

This paper discusses rectangular patch microstrip antenna design by using left-handed metamaterial (LHM). Designed is on FR4 substrate with dielectric constant of 4.4 and 1.6 mm thickness. LHM structure is intended for bandwidth enhancement. By using the AWR simulator, LHM structure has been designed on 60x50 mm² ground plane for rectangular patch microstrip antenna working on 2.4 GHz. Based on simulation results, the use of LHM structure is able to extend bandwidth up to 175.7 MHz with bandwidth enhancement reaching 213.75% larger than without LHM. The minimum return loss is about -21.93 dB on 2.4 GHz. The miniaturization ration of the patch dimension achieves 14.6%.

The research has been done to investigate the effect of gouging welding currents that tensile strength, hardness and microstructure welding A283 GrC steel. Variations of gouging current 200 A, 300 A and 400 A were compared with welding without gouging. Seam type used is a double V joint with angle 60⁰ and in using SMAW welding process. The test results are the highest tensile strength of 45.98 kgf/mm² at 300A gouging current and the lowest yield 45.51 kgf/mm² in welding without gouging. It shows the process of gouging reduce the ductility of the material due to the higher heat input. The fracture mechanism is more apt to occur in the current 300A gouging with the strain of 32.96% when compared to the non-gouging welding with a strain of 36.21%. The highest test result is 51 HRC on gouging current 400 A weld metal and the lowest area is 33.33 HRC on without gouging welding base metal regions. The results of microstructure observation showed that the increasing flow of gouging or heat input then occurs coarsening of grain or grains formed larger influence the outcome of toughness and hardness.

The synthesis and testing of the physical properties and microstructure liquid fuels (C₅-C₁₈) of poly propylene plastic waste pyrolysis results with temperature variation has been done. One way of processing biodegradable plastic waste by pyrolysis. The process is carried out at various temperatures of 105 ° C, 205 ° C, 325 ° C, and within 48 minutes, and the resulting steam is condensed through the condenser crossflow. The results showed that the liquid fuel close to the characteristics of gasoline, premium gasoline fraction composition (C_5-C₁₈) 85.11%. Physical testing of liquid fuels with ICEL 2700 that density is 0.8204 g / cm³ and an octane rating with ASTM D 2699 is 61.3. The results of FTIR spectrum of pyrolysed polypropylene have shown C = C functional group at 1648 cm^-1. GCMS analysis confirmed the availability of chain length of hydrocarbon between C₇ - C₂₇ which is mixture of kerosene and diesel fractions.

The friction brake is one of the key components in vehicle braking system. Friction mechanism in the braking system demands the brake lining to maintain its fraction coefficient and mechanical properties in various conditions. Research on the manufacturing process and material selection in the production of composite friction brake has been extensively conducted to obtain the expected characteristics. The purpose of research was to investigate the effect of the Nitrile Butadiene Rubber (NBR) on the flexural strength of brake composites which composed of NBR, phenolic resin, cashew dust, fly ash, cantala fiber, graphite and CaCO₃. NBR is commonly used as the filler composite in the production of composite friction brake. NBR is the copolymers of synthetic rubber made of acrylonitrile and butadiene which is resistant to heat and pressure. The three-point bending method was conducted to obtain flexural strength of composite friction brake materials according to the ASTM D790 standard. The result showed that NBR had effect on the flexural strength of the specimens. The flexural strength of the composite friction brake increases with increasing NBR filler content. NBR increases the flexural strength of composites due to its effect on improvement of the interfacial strength between fiber and matrix. The additions of 12% fractions volume NBR have the highest flexural strength.

Thermal spray is one of the most common coating technologies used in oil and gas industries. This research applied two thermal spray methods, namely High Velocity Oxygen Fuel for Molybdenum coating and Electric Arc Spray for Aluminum coating to compare the coating formed by different methods on stainless steel 316L substrates. The thickness of the Mo coating ranges from 15-20μm, whereas Al coating has a thickness of 90-100μm. Coating characterization was assessed by using several testing methods, i.e. the Positive Material Identification (PMI) to identify the coating composition, the metallographic testing to observe the interface bonding of substrate and coating, hardness test and wear test to characterize the mechanical properties of the coating and salt spray test to identify the corrosion resistance. Base on the PMI testing, the Al coating show 98.15% wt of aluminum, while Mo coating contains only 9.832% wt molybdenum. The SEM/EDX applied in the metallographic test shows that the coating has a mechanical bond with the surface of the substrate, in which the Mo coating has a more effective bond than the Al coating on the substrate. The aluminum coating has a lower hardness value of 96 HB, while the Mo coating is approximately 106 HB. The wear test shows the Mo coating has a better wear resistance than the Al coating because the Mo coating has a smaller slit width of 0.375mm. The salt spray test shows the two types of coating did not affect the scratched area but there is significant discolouring that indicates the formation of uniform corrosion.

Iron is widely used as construction material in industries, but iron will be easily corrosion when used in a corrosive medium.To overcome this problem, corrosion inhibitors are used.This study aims to use Awak Banana (Musa paradisiacal var. Awak) peel as iron corrosion inhibitor in 3% NaCl medium. In this experiment, the unripe Awak Banana peel acts as a corrosion inhibitor. The use of Awak banana peel as iron corrosion inhibition is varied in powder of banana peel, crude extract of banana peel, and tannin of banana peel. The results obtained that tannin of Awak banana peel, extract of Awak banana peel and Awak banana peel powder could be used as iron corrosion inhibition in NaCl Medium. After 12 days the iron is immersed in NaCl medium, the lowest corrosion rate is obtained by applying a tannin of Awak banana peel inhibitor, where the corrosion rate is 0.964 mpy. The highest inhibition efficiency amount of 67.9 % is also obtained by using tannin of Awak banana peel as inhibitor.

This study aims to determine the failure mode of ramie fiber reinforced epoxy composite materials (RFRECM). The method used is testing the composite test sample that includes tensile test according to ASTM D 3039/D3039M, compression test according to ASTM D 695, simulation by using computer software, and morphology analysis by using Scanning Electron Microscope (SEM). The results show that RFRECM has SR ≥1 for failure criteria derived from stress theory, strain theory, and Tsai-Wu criteria, while having SR <1 only for the criteria of Tsai-Hill. Theoretically, the epoxy flax fiber composite has good strength in fiber or longitudinal direction (0⁰) and decreases with the addition of the angle of the fiber. The failure mode of RFRECM is caused by voids, initial cracks, delimination and debonding occurring between 5-10% of the total area observed in the test sample. This condition can occur in all test samples as a result of imperfections of the fabrication process.

This study aims to determine the effects of graphene oxide (GO) addition to the properties of sago starch-based bioplastic. Bioplastics were prepared via the solution intercalation method while the GO was synthesized using Hummers method. The mechanical properties (tensile strength, elongation and Young's modulus), morphology and functional groups involved were studied. The interaction mechanism between the GO and the matrix composites was also proposed. From the mechanical properties analysis, the more GO addition and the longer mixing time, the more tensile strength and Young's modulus and the less elongation would be. The best tensile strength (4.018 MPa) was exhibited by bioplastic synthesized using 15% graphene oxide and 50 minutes mixing time. The micrograph analysis probed using Scanning Electron Microscopy (SEM) revealed that the GO filler in bioplastic synthesized with 50 minutes mixing time has been distributed evenly. The Fourier Transform (FTIR) analysis showed that a good inter-components interaction has been established due to the secondary O-H bonds between the GO and the bioplastic matric components.

This study aims to investigate the effect of fly ash content on the density, thermal conductivity, compressive strength and water absorption of Lightweight Foamed Concrete (LFC). This LFC consists of cement, water, sand, fly ash (FA) and foam. The foam is needed to to create air voids in the mixture and reduce its weight. The foaming agent which was diluted in the water was given air pressure using foam generator to produce foam. The LFC are made with water-cement ratio of 1:1 and cement-agregat ratio of 1: 4. Aggregates consisted of sand and FA varied by 0%, 10%, 20% and 30% in weight. The content offoam was 30% and 40% of the mortar volume. The increasing of foam content decreases density, thermal conductivity, and compressive strength of LFC. However, that increases its water absorption. The increasing of FA contentalso decreases water absorption, but it density, thermal conductivity and compressive strength.

This research studies the influence of graphene oxide (GO) addition and NaOH molarity to the mechanical, morphological and physical-chemical properties of Palm Oil Fuel Ash (POFA) based geopolymer. Geopolymer was made by using alkali activator solution (NaOH + Na₂SiO₃) with NaOH molarity variations of 6 M, 10 M and 14 M, while graphene oxide variations 0%, 0.2% wt, 0.4% wt, and 0.6% wt. The mechanical tests showed that the addition of graphene oxide, even though in small portion, increased the compressive strength of geopolymer significantly, likewise with the increase of NaOH concentrations. The highest compressive strength was 13.2 MPa exhibited by the geopolymer GO composites synthesized using 14 M NaOH and 0.6% wt of GO addition. X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy revealed that the NaOH reduced the GO via insitu reduction became reduced graphene oxide (rGO) sheets which filled the void sand creating a denser geopolymer structure. GO is the promising filler for compressive strength improvement of POFA based geopolymer.

This study aim was investigated the initial growth response of shallot against the activity of some Trichoderma isolates that were formulated in the form of oyster mushroom waste. This greenhouse experiment was prepared in a complete randomized design with the following treatments: without oyster mushroom cultivation waste, oyster mushroom cultivation waste without Trichoderma, oyster mushroom cultivation waste with Trichoderma isolate Tc-JJr-02, oyster mushroom cultivation waste with Trichoderma isolate Tc-Pjn-01, and oyster mushroom cultivation wastes with Trichoderma isolates Tc-Clkt-02. All treatments were repeated four times to obtain 20 experimental units. The variables observed were plant height length and number of leaves. Data obtained were analyzed statistically by an analysis of variance (minitab Release 14 sofware) and HSD test were used to indicate the significant differences between the mean values (p<0.05).The results showed that Trichoderma was formulated in oyster mushroom cultivation wastes increased the height and the number of leaves on the initial growth of shallot crops.

The objective of this study was to compare the effect of sex on meat quality parameters of the meat of bulls and heifers of the Fleckvieh cattle reared and finished under identical nutritional and management conditions and slaughtered at an identical age of 19 months. Physical meat quality measurements, proximate chemical composition and sensory analyses were performed on musculus longissimus lumborum, musculus triceps brachii and musculus rectus abdominis from total 23 bulls and heifers. The evaluation of chemical composition shows that the meat from bulls contained less dry matter and intramuscular fat. Lower shear force values as well as lower total collagen contents and higher soluble collagen proportions were measured in heifer samples. When the three different muscles were compared, it appeared that musculus rectus abdominis exhibited the highest contents of dry matter and intramuscular fat whereas musculus triceps brachii had the highest amount of total collagen and also the highest proportion of soluble collagen. Musculus longissimus lumborum contained the highest proportion of protein, the lowest proportion of total collagen and exhibited the lowest shear force value. Musculus longissimus lumborum was assessed as the tenderest with the most favourable score for fibrosity and chewiness, musculus triceps brachii had the highest score for beef odour intensity and beef flavour intensity and musculus rectus abdominis was scored as the juiciest. With the exception of beef odour intensity, the meat from heifers was assessed by the sensory panel as more favourable for all the remaining sensory characteristics assessed.

Drought tolerant genotype has to be created due to changing of world climate. Performance of Arabica coffee offspring might be affected by parental environment. In North Sumatra province of Indonesia, Arabica coffee were growing at a wide range of elevation, precipitation and temperature. Hence, drought tolerant genotype might be available in this coffee plantation. The objectives of this research were to determine effect of water stress on performance Arabica coffee genotypes. Seven genotypes which were selected from seven different environments as well as four level of water treatments (100%, 75%, 50%, and 25% field capacity) were used. Paramaters were increment of plant height, stem diameter, and leaf number. Factorial experiment namely completely block design with two factors and three replications was conducted in the green house. The result revealed that interaction of genotype and level of water treatment was highly significant. Genotype Tobe2 seemed to be the most tolerant to water stress. Increment of leaf number of descendant had a negative significant correlation with minimum precipitation of parental environment. Increment of stem diameter of offspring positively significantly correlated with average temperature of parental environment. It could be concluded that it could be possible to carry out selection for drought tolerant genotype from the existing population of Arabica coffee. However, selection should be conducted in a controlled condition due to significant GxE interaction.

Indigenous technology in utilizations and handling of palmyra palm sap were studied in two regions of East Java, i.e at Gunungsari village, Beji, Pasuruan, and at two districts in Sumenep, Madura, which were known as one of palmyra palm plantation centre in East Java. Field observations and interviews were carried out to some farmers that taken by purposive sampling. Result of this research shows that there were differences in utilization and handling of sap between two regions. All of farmers in Gunungsari utilize sap in fresh sap called legen as their produce, and some fermented sap, wine called toak and further fermented as vinegar. On the other side, farmers in two districts in Sumenep, 96.7 % at Pragaan and 100 % at Dungkek process their palmyra palm sap into jaggery or palm sugar, this is due to high production of sap in this region as Sumenep still has high palm population. At Gunungsari, farmers preserve sap by boiling fresh sap after four hours tapping process if they do not need to ferment it to wine or vinegar. In Sumenep, according to sap utilization as palm sugar, they preserve the sap by adding sap a pinch of gum-lack tree (Schlechera oleosa) bark or cashew (Anacardium occidentale) leaves during tapping. Analyses of sap samples from two regions taken in wet season showed that total soluble solid contained were not significantly difference, it ranges from 9.47 until 11.67 brix. Reducing sugar contained in sap from Sumenep was the lowest, i.e 0.67 % compared with those at Gunungsari 2.10% for fresh and 2.04% for boiled sap. Sap preserved by adding gum-lack tree bark had higher total soluble solid and reducing sugar than the boiled one. The tapping, collecting, utilizations and handling of palmyra palm sap in two regions still carried out traditionally, technology innovations are urgently needed in these regions.

Kefir is a fermented milk drink produced by the actions of bacteria and yeast contained in kefir grains. It's have a unique taste and unique properties. The industrial manufacture of kefir using grains as the starter culture is very difficult due to complexity of their microbiological composition, which varies widely depending on the origin of the grains and conditions of storage and handling. Instant kefir (powders) which produce in the research may provide the solution to extend the industrial manufacture of kefir. The purpose of this study was observed the effect of banana flour and kefir on yeast and lactic acid bacteria production. This study used descriptive method. Fermentation at room temperature for 48 hour to produced kefir. Instant kefir samples were prepared used of 10, 15, 20, 25, 30, 35, and 40% (w/w) banana flour, dried and than milled and passed through at 80-mesh. This research shows that instant kefir with 10% banana flours produce the highest yeast and lactic acid bacteria. Amount of microbial in the kefir are 8.8 x 10⁴ cfu/ml yeast and 9.8 x 10⁵ cfu/ml lactic acid bacteria.

This study aims to determine the effect on various intensity of light on the response of vegetative growth of local soybean to vegetative three stadia. Greenhouse experiments with 15 experimental units were prepared in a completely randomized design with treatments consisting of: without shade, 50, 60, 70, and 80% shade. The observed variables are plant height, number of leaves, number of branches, and stem diameter, root length, wet weight, and dry weight of stove. All data were analyzed by variance followed by All data were analyzed by variance followed by LSD test at 5%. The results showed that shading percentage had an effect on plant response on all growth variables until the end of vegetative-3 stage. The higher the shade percentage, the more increase the growth of plant height and root length, but on the contrary decrease the growth of the number of leaves, in effect on the decrease of leaf number, branch number, stem diameter, and wet weight and dry weight of plant.

French fries is one of the most favourite foods, usually made of potato. Cocoyam has similar characteristics with potato, so it may substitute potato, as it price much cheaper than potato. This study aims to determine the effect of various edible coating (CMC, maltodextrin, and carrageenan) and calcium chloride (CaCl₂) concentration (0%, 1%, 2%) on characteristics of cocoyam french fries. Randomized block design that arranged as factorial was used in this experiment. The difference between the mean values were analyses using Tukey test (p<0.05). The results of this study showed that kinds of edible coating and concentration of calcium chloride significantly influenced texture and texture organoleptic characteristics of new cocoyam french fries. The best treatment was obtained from concentration of calcium chloride 0% and maltodextrin as edible coating. French fries from this treatment had moisture content 39.00%, hardness value 17.67 cm/g sec, and weight loss value 36.47 g. On the organoleptic characteristics had score of taste 4.90 (like slightly), aroma 5.60 (like), color 6.20 (like) and texture 4.95 (like slightly). Based on the results, french fries from cocoyam that coated with maltodextrin had preferred characteristics.

Plant-derived compounds (carvacrol, cinnamaldehyde, eugenol, 8-hydroxyquinline, thymol, and thymoquinone) were assessed for their in vitro growth-inhibitory effect against Pseudomonas aeruginosa. For this purpose, the broth microdilution volatilization method evaluating antibacterial activity simultaneously in liquid and vapour phase was used. This recently developed screening method is performed in 96-well microtiter plates, it combines principles of standard broth microdilution assay with disc volatilization test. The results showed 8-hydroxyquinoline and thymol as the most effective antibacterial agents with the lowest minimum inhibitory concentration 256 µg/mL for both compounds.

Maltodextrin is produced by hydrolysis process using enzyme catalyst. This enzyme catalyst is used because it is able to catalyze the process of starch hydrolysis to produce simpler molecules such as glucose, maltose, and dextrin. Maltodextrin is an imperfect starch composed of a simple, low-calorie mixture of sugars. The hydrolysis process takes place by varying the enzyme concentrations of 10%, 15% and 20% and varying the time 60 minutes, 90 minutes, 120 minutes. The optimum condition obtained in the process of hydrolysis of starch to maltodextrin in this research is at hydrolysis time of 120 minutes with enzyme concentration 20% yield equivalent of 13,4% dextrose, water content 4,3% and pH 5.

The aim of this work was to evaluate influence of milking settings optimization on milk yield (MY), milking time (MT), average milk flow (AMF) and somatic cell count (SCC). Pulsation ratio was changed from 60:40 to 63:37; pulsation rate from 60 to 62 pulses per minute; and critical milk flow for automatic cluster remover (CMF) was decreased from 0.85 to 0.65 kg.min^-1. Experiment was conducted on Holstein production herd (n=370) from March to May. SAS 9.3 was used for statistical evaluation. Changes significantly influenced all evaluated parameters (P <0.05). Slightly higher MY (+0.16 kg, P <0.05) was observed before changes. Naturally, the milking time was significantly prolonged (+0.26 min; P <0.01) by decreasing the CMF. This change also prolonged decline phase of milking, so the AMF was significantly reduced (-0.17 kg.min^-1, P <0.01). On the other hand, MT prolongation was not that critical due to increases in pulsation settings, which helped to reduce the negative influence of lower CMF on MT. Milking setting adjustments had positive effect on udder health, with significant drop in SCC (-64.78 thous./ml, P <0.01). In conclusion, milking settings adjustments are viable way of achieving various farm goals; like better udder health, less residual milk and many more.

Tomato tree (Solanum betaceum, Cav) has a high economic value. Consumed as fresh and processed fruit such as juice and syrup. Tomato tree has small seeds, a lot of seed and hard seed coat, so it requires a special handling on processing. Gibberalin hormone can increase fruit size and play a role in the formation of a little of seeds (seedless). This study aims to determine the effect of Gibberelin (GA₃) on producing of parthenocarpy fruit. Conducted in April - August 2017 at experimental garden of Vegetable Research Institute at Tongkoh Berastagi Sumatera Utara, Indonesia. Gibberellin applied with five concentration, they are: 0 ppm as a control (G₀), 10 ppm (G₁), 20 ppm (G₂), 30 ppm (G₃), and 40 ppm (G₄) aplication by sprayed directly on the flower bud for six times and lapse of 3 days. The parameters observed were the percentage of fruit formation, the thickness of the flesh, the weight of the fruit, the weight of the fruit flesh, the weight of the seed, the number of potential seeds, the pithy seed, and the degenerated seeds. The results showed that the application of Gibberelin had significant effect on the decrease of number of potential seeds, seeds and increased degenerated seeds, but no significant on the percentage of fruit formation, the thickness of the flesh, the weight of the fruit, the weight of the flesh and the weight of the seed. The average number of potential seeds, seeds, and degenerated seeds was significantly different at each dose. The lowest number of seeds was found at concentrations of 40 ppm (G₄).

The most important processes in food processing include drying. Generally it is the removal of water from the material for further processing or storage. This study was focused on the analysis of drying process of green coffee beans (Coffee arabica). The green beans, originally from Indonesia, were used in this experiment. Moisture content of beans M_c = 28.1 ± 1.7 % (w.b.) were determined. The beans were dried at different air temperatures T_d = 40, 60, 80, 100 and 120 ± 1 °C. Drying tests were carried out on drying scales (Radwag, MA 50.R, Poland). The test was repeated three times for each temperature. Measured data were analysed by computer software Mathcad 14. Experimental drying curves at different temperatures were determined. The measured values of the drying curves of green coffee beans were fitted and a mathematical model was created. Model coefficients were determined and the proposed model was statistically analysed.

Nowadays, soil degradation is a very discussed global problem. Since the population grows while the space for primary production remains limited, it is necessary to modify agricultural practice to fulfill all population needs. The concept of precision agriculture aims to utilize modern technologies to make the agriculture more effective. Maize is one of the crucial crops worldwide. However, its cultivation has a negative influence on the soil, because it depletes the nutrients and since the sewing distance is relatively high, the soil is also endangered by water or wind erosion. This study aimed to evaluate a 1.6 agricultural plot in North Sumatra, Indonesia, where there is maize cultivated in a very intensive mode. The influence of degraded soil on maize yield was the main issue. Soil sampling showed that there is only slightly lower amount of copper, otherwise the soil nutrients content are on optimal levels. Since there were no yield data evaluated, yield was estimated by calculating Normalized Difference Vegetation Index derived from free Sentinel-2 satellite imagery. Four growing season were evaluated. Mean values of NDVI did not show any trend (0.579; 0.667; 0.621; 0.572). Four vegetation seasons seem to be a very short period to observe any significant results. Thus, this paper may be understood as a study with preliminary results that may be repeated in future to see potential influence of intensive maize cultivation on soil properties.

The extraction process of anti-microbial compounds from F.lyrataWarb fruit and leaf had been identified. The study employed a maceration extraction method used water as solvent agents, to extract seconder metabolite, example phenolic, flavonoid, tannin as an anti-microbial agent. The compound which is known to have an inhibition effect to decline the growth of the microorganism of food quality decreasing triggers. Its effects were subjected to 3 tested bacterias, i.e.; Pseudomonasaeruginosa, Escherichia coli, and Bacillus subtilis. This study purpose to determine and compare the content of phytochemicals and antimicrobial activity in leaf and fruit extracts. Experimental laboratorium was conducted and the data analyzed by descriptive analysis in this research. The statistical test used is two sample tests, which aims to know the difference in mean value between leaf extractwith fruit, which is not mutual related. Results indicated the formation of the inhibited zone in the tested media which proved by the Kirby-Bauer testing method are different between fruit and leaf extract.

A total of 60 crossbred pigs were divided to 3 feeding groups - ad libitum (AL), restriction (R1) and strong restriction (R2) and the effect of feed restriction on muscle fibre characteristics of musculus longissimus lumborum (MLL) and meat quality traits were evaluated. Muscle fibres were stained and classified as fibre types I, IIA and IIB. For each muscle fibre type, the fibre density, fibre cross-section area (CSA) and fibre proportion were determined. Fibres IIB were divided to small-, medium- and large-sized fibres. From qualitative meat parameters, meat colour, tenderness, water-holding capacity, pH, and electrical conductivity were measured. AL group had significantly lower area percentage of IIB fibres and lower CSA of IIB fibres than restricted groups. R2 group had significantly higher content of large-sized IIB fibres and lower content of medium-sized IIB fibres than AL group. Ad libitum fed group had the highest back fat thickness and the lowest lean meat content and tended to have better meat quality traits compared to other groups. The results of this study showed that strong feed restriction had a negative effect on muscle fibre composition, especially amount of large-sized fibres IIB, which are associated with poor meat quality.

This research has been conducted for 3 (three) months in April to June 2018. The research includes the maintenance of test animals and the manufacture of extracts that will be in the Basic Laboratory of Universitas Samudra. The method used in this study consisted of making coffee extracts, making combination of solvents and test activity of preparation. Hair length data and hair weight obtained were then processed statistically to see if there was a significant difference between the test area and the treatments. Normal and homogeneous data distribution is processed for the analysis of variance (ANOVA). The results showed that treatment 3 (0.113 cm day^-1) on day 21 was faster than positive treatment (0.101 cm day^-1), negative treatment (0.060 cm day^-1), 4 treatment (0.099 cm day^-1) and 5 (0.090 cm day^-1) treatment. From the measurement of hair weight measured for 21 days showed treatment 3 resulted the largest hair weight of 0.207 g, followed by positive treatment 0.193 g, 4 treatment of 0.187 g, treatment 5 with 0.177 g and the lowest weight was in the treatment negative by 0.127 g.

Microorganisms play an important role in maintaining soil fertility and plant health. They can act as biofertilizers and increase the resistance to biotic and abiotic stress. This study focused on the isolation and selection of endophytic fungi associated with mangrove that have ability to promote the growth of Orizasativa L. Cempoireng. Assessing the growth of plant was study in vitro test by using PDA as a media. A total of 17 fungi were found in leaf, stem and root of mangrove and classified into 6 morphotypes according to colonies characteristics and form of mycelium. The best isolate (the endophytic fungi with characteristic of white fungus colonies mycelium septa and non-septa revealed the high ability to promote the germination seed and growth of CempoIreng. Overall, the study indicated that the endophytic fungicontributed the positive effect on the growth of Oryza sativa L. "Cempo Ireng".

Milkfish is one of fishery commodity that has big enough potency to be developed. But there are some obstacles in the development process, which one is feed. Feed becomes one of the limiting factors in milkfish cultivation, especially in hatchery business. Therefore, it is necessary to intensify the milkfish cultivation by using Artemia salina in capsule form with vitamin C cultivation as natural food of milkfish at the time of hatchery. The purpose of this study is to know how the effect of feeding Artemia salina in capsule form with the addition of vitamin C and to know how the effect of feeding Artemia salina in the form of capsules with the addition of vitamins to the growth rate of milkfish seeds. The design used was a complete randomized block design (RAKL) factorial pattern, with 2 treatment factors ie feeding time and Artemia salina dose. The data were analyzed using ANOVA at 5% significance and continued with the Smallest Differential Differential Test (DMRT).The result showed that the feeding of Artemia with the addition of vitamin C 400 mg/L at 08.00 am increased the average length and weight of milkfish juvenile after treatment compared to others time feeding. On the other hand, the best time feeding for the rate of lenght and weight of milkfish juvenile was observed at 16.00 pm.In general, it can be conclucded that the feeding of Artemia with the addition of vitamin C 400 mg/L at 16.00 WIB effectively increased the average length and weight of milkfish juvenile after treatments.

The objectives of this research were to investigate the growth and yield response of paddy rice on transplanting seedling ages and number of seedlings per planting hole. This research was conducted in October 2016 until January 2017 in Petuaran Hulu Village, Pegajahan Subdistrict, Serdang Bedagai Regency, North Sumatera Province. The experimental design used was a Randomized Block Design with two factors and three replications. The first factor was the age of transplanting seedlings with four levels (12, 16, 20, and 24 days). The second factor was the number of seedlings per planting hole with four levels (1, 2, 3, and 4 seedlings per planting hole). Analysis of Variance was conducted in order to see the effect of the treatments. The treatments that showed significant effect was tested with Duncan to compare among treatments effect. The results showed that transplanting seedling age and number of seedlings per planting hole had significant effect on plant height, number of tillers, but no significant effect on stem diameter, number of productive tillers, panicle length, and productivity. The effect of interaction of the two treatments had no significant effect on all observed parameters. Transplanting seedling age of 12 days and one seedling per planting hole was suggested to be applied for rice cultivation.

Euthynnusaffinis is one of tuna species that distributed throughout the world. Their visceral accounts for approximate less than 20% of body weight and its value are still underutilized. This study screened four the potential individual visceral organ to produce protease and lipase enzyme viz. spleen, stomach, pancreas, and liver. Among the individual visceral organ, liver exhibited the highest source for protease activity (57.786 U/ml), while pancreas revealed as the best source for lipase activity (69.425 U/ml). Therefore, the finding of alternative sources for protease and lipase in this study might converted visceral waste by product to generate protease and lipase enzyme that may be applied in biotechnological process.

This study aims to hide data or information on pixel image using EOF method and to improve the security of hidden data than combine with cryptography algorithm Modular Multiplication Block Cipher algorithm for the encryption process. The image file used as the test sample consists of 3 types of image types (JPG, BMP, PNG), this file type is the most widely used by users with different width and height as well as various file sizes. The results of this study prove that the data could embed in pixel image using EOF method and the file size of carrier will increase its capacity as byte of embedded text.

Errors in data transmission cannot be known directly when the data transmission process is fulfilled, but error is often prevalent in data transmission. Faulty or missing frames or bits are standard errors and to control or check errors requires a unique method, in this case, the Stop-and-wait method, Go-Back-N and Selective Reject are methods that can be used to do so, comparison of time of error checking process with Stop-and-wait method, Go-Back-N and Selective Reject is very important to get the right method to check the ignorance, from testing performed that the method of Go-Back-N is much faster than the other methods.

Recent studies of attribute independent assumptions on Naïve Bayes (NB) typically generate data sets, methods and frameworks that enable researchers to focus on development activities in terms of finding solutions to attribute independent issues, thereby enhancing the quality of NB classification and better utilizing resources. Many data sets deal with the NB attribute independence issues and different frameworks, so the overall picture of the independent assumption of the current NB attribute is not yet complete. This literature review aims to identify and analyze the research trends, data sets, methods and frameworks used in the attribute independence assumption research on NB for data classification between 2010 and 2018. The results of this research identified three frameworks that are highly cited and therefore influential in the software defect prediction field. They are Langley and Sage Framework, Friedman et al. Framework, and Wu et al. Framework

Coal is one of the most widely used energy sources in the world, and Indonesia is one of the coal exporting countries. Therefore, Indonesia's long-term availability of coal must be maintained, to support various industrial projects and the world economy. One way to maintain coal reserves is to predict the timing data of coal exports, to make it easier for the government to issue a coal export policy. In this study, the prediction method used is back propagation algorithm. The algorithm is able to solve many problems by building a well-trained model that shows good performance in some non-linear problems. The function used is bipolar, because this function is able to calculate data whose value is not stable. The data used in this study is the data of Coal Exports in Indonesia based on the main destination countries processed from customs documents of the Directorate General of Customs and Excise and Statistics Indonesia. This study uses 3 architectural models, namely: 4-5-1, 4-10-1 and 4-15-1. The best architectural model is 4-5-1, yielding 93% accuracy, Margin eror 7%, MSE 0,0117017098 with error rate 0.001 - 0.04. It is expected that these results can predict well.

The purpose of this study is to determine and predict coffee exports in Indonesia based on the main destination countries for years to come. The results of this study are expected to be widely used for both government and private sector as an evaluation material in coffee, economic and business development. The data used in this study is Coffee Exports In Indonesia based on the main destination countries in 2006-2015. Data processed from customs documents of the Directorate General of Customs and Excise cited from Indonesia Statistics Publication. This research uses artificial neural network Polak-Ribiere updates which will be combined with bipolar activation function and linear function. The architectural model used there are 4, among others: 8-10-15-1, 8-15-10-1, 8-15-30-1 and 8-30-15-1. The best architectural model of the 4 models used is 8-10-15-1 with error rate of 0.001-0.06, alpha = 0.001, beta = 0.1, delta = 0.01 and gama = 0.1. The resulting accuracy is 86%.

Indonesia is an agriculture-based country. Agriculture is a sector that becomes the backbone of Indonesia's economic development and improvement. Food security is one of the most important of farms. There are several types of food crops that become important commodities for the nation of Indonesia namely rice, corn, peanut, green beans, cassava and sweet potatoes. This research data is sourced from BPS-Statistic (https://www.bps.go.id/). This research raised the topic of rice crops clustering by province (1993-2015) using data mining with K-means method. The method used with the help of rapidminer software. The sample data used are 34 provinces in Indonesia with 3 parameters, namely: 1). Lack of Harvest Area (hectares), 2). Productivity (quintal / hectare) and 3). Production (ton). Cluster results using 3 clusters: (C1) high production cluster, (C2) normal production cluster and (C3) low production cluster. Based on the research results obtained (C1) high production cluster = 3 provinces, (C2) normal production cluster = 23 provinces and (C3) low production cluster = 8 provinces. This study also uses "% performance" to see the accuracy of the algorithm used with the research topic. From the result of accuracy using parameter average within centroid distance and Davies Bouldin obtained Davies-Bouldin index for rice plant is -0.392. Based on these performance results can be summed up as the best algorithm based on criteria. The lowest cluster clustering (C3): Aceh, North Sumatera, West Sumatera, South Sumatera, Lampung, West Nusa Tenggara, South Kalimantan, and South Sulawesi are input inputs to the government, to provide socialization to the province to increase rice production, is one of the commodities of Indonesian people, especially rice.

It is a common fact that every parents wants their children to get achievements, especially academic achievements. Demands by demands then addressed to their children to get higher and higher score in every subjects. However, parents and teachers are often forgot about one thing, besides of just demanding the children to get high scores, they also responsible in providing the best conditions to boost the children's potential and performance. To help solving this issue, the author used data mining model in binary classification approach. Data mining methods that author chose was decision tree due to its high accuracy comparing to the neural network and support vector machine that have lower accuracy than decision tree. Despite of previous result that is the main factor that affects student performance, in this research, we also found several factors of environments that may affects the student performance

Changing business and market environment render the implementation and support of IT division obsolete and not relevant. In this paper we assess and analyze the implementation and support process using ITIL v3 - COBIT 5 Mapping. With objective to create practical guidance for measuring maturity of the process, assess capability level of the process, and make recommendation that can be applied to company's business process. As the result of assessment, we conclude that mean capability level of implementation and support process is 0.71. This indicates that majority of the process do not achieve level 1 capability level and failed to achieve its objective or fail to deliver any process evidence. As for recommendation we propose two short term solution, fulfill uncompleted base practice and focusing in development of Information Management System.

This study aims to analyze the comparison of object clustering results in big data using K-Means method and K-Medoid method. Combination testing using three algorithms namely Ecludiance Distance, Canberra Distance, and Chebyshev Distance respectively for both methods. The sample of the research is the data set of students of three classes with six variables with a total of 147,679 data. The test results found that K-Means method is more optimal in data clustering than K-Medoid method, both in Ecluid Distance, Chanberra Distance and Chebyshev Distance algorithms which in overall comparison of clustering process with 1: 110.7 rationality. The results also suggested not to useChanberra Distance algorithms for both K-Means and K-Medoid methods because the cluster quality index in the Davies Bouldin test was undefined (∞). The best level of accuracy and quality of cloning is to use K-Means with Chebyshev Distance method, which is to produce five clusters with 0.1 second processing time

Deep Learning is a new breakthrough in the area of neural network. One of it methodology is Deep Neural Network. Usually, deep neural network is a method that can solve problems such as classification or prediction. Here in this study, we collect data for mangrove classification, and we see an opportunity to classify the type of mangrove based on its features using deep neural network. Research on mangrove plants related to classification is more widely used in mangrove dispersal spread through spectral and hyperspectral satellite images than using real value data such as morphological data, thus providing blank space for researchers to use mangrove morphological data. This initial study is to build a deep neural network architecture and analyze it in term of mangrove sprout plant classification. The result from our architectural methodology of this research is reaching the lowest training error of 0.1345 and the highest testing accuracy value of 98%.

The objective of this study is to develop learning media by using the Computer Based Instruction (CBI) model for GOST algorithm cryptographic material (Gosudarstvennyi Standard). Besides, the study serves to present learning using computer media, especially in the Informatics Engineering study program. The method used in this study uses the Research and Development (R & D) method. The results of this development research are learning media products in the form of tutorial CDs with the contents of the material: GOST Cryptographic Theory, Encryption Process and Decryption process using alphabet text data. Based on the results of the application and testing of the program, it can be concluded that this application is easy to use. Learning the Gost algorithm in the encoding method utilizing the Computer Based Instructions (CBI) method helps to understand the material and facilitate the learning process.

Face shape classification is useful for grooming personalities, such as the selection of haircut, the selection of facial makeup, the selection of glasses frames or even the selection of appropriate shirts. The face shape in men is divided into six forms, namely: oval, round, diamond, rectangle, triangle and square. Facial shape determination has been introduced by many beauty experts, but for society, in general, is still a little difficult to classify it because the form of each face is almost the same and manual measurement requires a long process. That's why it needs a method to classify face shape quickly and precisely. A proposed method in this research is Probability Neural Network and Invariant Moments. Men face images are used as input for image processing. The stages before classification are image pre-processing (Gray scaling, Scaling, and Gabor Filter). Then feature extraction using Invariant Moments. The final step is classification using Probability Neural Network. After testing is done to 90 data training and 30 data testing, it was concluded that the proposed method has the capability to classify men face shape with accuracy 80%.

The purpose of this study is to determine the factors that encourage the use of visual electronic banking system (VEBS) application in Bank Central Asia Corporation, and provide an idea to increase the use of VEBS. This study using UTAUT 2 model approach. The primary data obtained from interviews, direct observation and questionnaires that distributed and processed using SEM-PLS. The results of this study provide qualitative calculation results of UTAUT 2 variable. The conclusion obtained that interest of the use of application VEBS affected by variables facilitating condition, performance expectancy and behavioral intention. From these conclusions this study provided an idea to the future development of application's features for more effective and efficient use.

A fungus is a type of plants that have no chlorophyll, and its life depends on other living things. The fungus has various types. Some mushrooms are useful and utilized in the field of culinary, health, economy and agriculture, but there are poisonous ones that can cause infection and even death to humans. Research on fungus identification is insufficient, and the conventional method still becomes the main choice in identifying them. Therefore, an alternative is required to identify the poisonous mushrooms. The method proposed in this study is K-Nearest Neighbor. Mushroom image served as the input image of this image processing process. Before identification process, the image will go through image pre-processing step using gray-scaling, image segmentation using canny edge and thresholding, and feature extraction process using zoning method. 40 images of fungus plants were used to test the system. The accuracy rate of the system in poisonous mushroom identification is 90%.

K-Nearest Neighbor is the algorithm that included into the category of algorithms supervaised learning is bound process to distinguish the classes that already exists. Nearest neighbor is calculated based on the value of k that determines how the nearest neighbor in consider on the distance class data for k-nearest neighbor based on the determination of the value of the k. The determination of the class test data local mean based k-nearest neighbor using the measurement of the distance closest to each using eucllidean distance from each class data. Model based approach the weight of Gini Index is in need to give the weight of each attributes to determine the value of k. Research In this time I get the results of k best at the thyroid data which is a type of unbalanced data to obtain the value of the k highest k=44 until k=46 with accuracy of the closest neighbors of 71,19% and the value of the k lowest is k=50 of 69,30%. Then the results of the value of the k=44 until k=46 become k best on the processing of this time. It can be concluded for the data class is not the same will result in class data become random repeatedly until the limit of the determination of the value of k as well as exceeding the value of the k highest.

Simple Additive Weighting (SAW) is one of Multi Attribute Decision Making (MADM) method known as simple weighted linear combination and most used. However, based on several studies, it produces lower accuracy values than other MADM methods. Because there is no validation in the weighting system for each attribute so that it affects the decision-making process and for some newly incompatible attributes causing errors in decision making and determining the best alternative. In this study, researchers used gain ratio as the basis of attribute weighting on SAW. Datasets used from UCI machine learning repository, such as cryotherapy, immunotherapy, ILPD and user knowledge modelling. The accuracy result of this research will be compare with the result of SAW method accuracy value based on the weight of the dataset using relative standard deviation. The average value of accuracy obtained by weighting attributes based on the weight of the dataset of 28.1825% and weight gain ratio of 31.6975%. Then on attribute weighting based on the gain ratio has a better accuracy. However, the Cryotherapy dataset value accuracy based on the weight gain ratio more 0.5% lower than the weight of the dataset due to the value in the spread dataset.

A good application system can be seen from the user's satisfaction. Service-Now is an application used by the service desk division at PT Aero System Indonesia for the needs of customer reports. Many employees face obstacles in operational service-now, so the resulting report is not optimal. In this study will measure the level of user satisfaction on the service-now application. The study was conducted by taking a survey involving 32 staff in the service desk division as respondents. An approach the Importance Performance Analysis (IPA) is used to analyse the data. The results of analysis show ease of use, completeness of a function or feature, and timely enough to satisfy the user. Meanwhile, quality of information needs to be increased in service-now applications to improve user satisfaction.

Anemia is one of the most common types of diseases experienced by people in developing countries but gets less attention to deal. Currently, smartphones applications can be utilized to support the process of anemia detection using an image of the conjunctival pallor. The K-means algorithm can be applied to cluster the pixels of conjunctiva pallor images which are represented in digital characters with red (R), green (G), and blue (B) formats. The clustering results from the under eyes image will be represented by the hemoglobin concentration, which is used to determine whether a person suffers from anemia or not. The function of this application is facilitate the user to perform anemia detection anytime and anywhere. Test results from this application indicate that the detection process gives the accuracy of 90%. This means that the result of detection through the application has a similarity of 90% with the results of detection using the EasyTouch®GCHb hemoglobin test.

Customer loyalty is very much needed in the e-Commerce business. The use of social media is one of the new ways to maintain customer loyalty. Ngapakbanyumas.com is one of e-Commerce in Purwokerto, and the goal of this research is to find out the correlation between the influences of social media to maintain the loyalty of its members. This research had done the survey to 257 of its registered members on Facebook. Multiple linear regression method is used for data analysis. This method has the results: social media plays a huge role to increase the possibility of rebuying and loyalty behaviour, but this strategy has no impact on mouth-to-mouth sales.

The Existing times of fundamental technological change. The rapid advances in technology changing the way we live, work and relate to one another. The three previous industrial revolutions all created major societal change and opportunity, but today's transformation is unique in terms of the great speed with the new ideas and technologies. Consider the unlimited possibilities of having billions of people connected by mobile devices, giving rise to unprecendented processing power, storage capabilities and knowledge access. The technologies driving the fourth industrial revolution. The potential of Indonesia's natural wealth is remarkable, both biological and non biological natural resources. The wealth when viewed geographically, from Sabang to Merauke. With a large island and thousands of small islands that surround the nature of Indonesia. Therefore, Indonesia is an archipelagic country that has enormous natural wealth.

In celebrating Indonesia's 73 years of independence, at August 17, 2018, it is important to invites all people of Indonesia to conduct self-evaluation, why various problems such as: poverty; gap between the have and don't; deforestry; land distruction; and the storm of industrial fourth era revolution (Industry 4.0) will creating unemployment; potential for widening economic inequality, etc. Next, the question is how to make the sustainable development in the wake of the 4th industrial revolution in Indonesia

The Constitutional Court of The Republic of Indonesia is an institution which has authority to judge and examine constitutions. In this institution, each component has responsibility to manage their own finance and budgeting. Based on this case, they need a solution to summarize the amount and absorption of the budget in every component. This paper proposes a solution to design a data warehouse model to process and analyse the down payment administration data. The nine steps design methodology for developing data warehouse is implemented in this work. This paper aims to bring some benefit for The Constitutional Court, especially in form of information about down payment absorption for every component each year. The result is presented in form of pdf report and informative dashboard using data warehouse tools.

Employee's rotation is often performed in organization. In some periods, the rotation is performed to meet organization's requirement. However, it also indirectly leads to a decreased of organizational performance when there is a gap between job specification and the ability of employee. This problem can be handled by managing the knowledge of employees which is called knowledge management (KM). Specifically, in Indonesia, the employees who work as teachers in state high school have the high rate of employees' rotation. Therefore we need to perform KM in this condition, we must find out some factors that affecting readiness of KM implementation. The founded factors can be used to assess the readiness level of organization to implement the KM. This research proposes a method to find out factors which affecting the readiness of KM implementation in state high school of Indonesia and how importance are these factors using Analytical Hierarchy Process (AHP) method. The case study was take place on state senior high school in Palembang which is a capital city of South Sumatera. The result shows the affecting factors are collaboration, learning, top management support, IT Support, business strategy, ICT Use, performance expectancy of KM, effort expectancy of KM, and informal consecutively.

As a company which relates its customer service, a software company (this case is PT Boon Software) is induced to give the good service to its customer. The existing information technology (IT) system service is made by patchwork. It brings some problems in service catalog, problem managment, change management, and service level agreement (SLA). The purpose of this research is to implement helpdesk system to software company with Information Technology Infrastructure Library (ITIL) framework as a standard reference to solve various problem related information technology service on a company. This research starts by investigation all stakeholders of the company with some questionnares. Implementation ITIL is strated by finding the gap between the current condition and the standard base line in ITIL. After implementation IT service using ITIL, the stakeholders are asked the same questionnares. The result shows that there is significant different before and after implementing system service using ITIL.

The increasing number of servers used to support all the activities that assist the production of a company. Usually, it will be a waste, because a physical server cannot share resources such as CPU, RAM, and network. It will force the company to buy a new server each time to implement a new system. Therefore, we examined and analyzed the comparison of performance on a physical server with a virtual server that is built as an IP camera server to answer the needs of the company. After testing and getting the data, we conclude that in the testing of a turn on, restart and shut down servers, virtual servers have very much superior performance compared to physical servers. While in terms of performance of the CPU, RAM, and network, both physical servers and virtual servers do not have a significant difference. However, the important notes are in virtualization, it can perform resource sharing, and this technology is needed by companies in this era.

IT governance framework has emerged as important aspects for all organizations. Organization that has lack of IT governance also experiences lack of good corporate governance. As a result, the organization has difficulties to link its IT benefits to organization's objectives. In some cases, the lack of IT governance even causes severe impacts to school management. The article takes case of a higher institution, STMIK MBM, one of popular IT school in North Sulawesi, that has experienced with frequent IT interruption. The frequent IT interruption has caused severe consequences not only to current school operation, but also to the reputation of the school. In the beginning year of 2017, the ineffective academic data management has caused the severe interruption of school operation and led to the change of school management. To promote IT good governance, the new school director has initiative to apply COBIT 5, as an effective IT governance framework for the school. The article provides an analysis of COBIT 5 implementation with the objectives to provide a reference for major school stakeholders to understand and develop effective business and IT policy. The outcome is expected to provide insight of good IT governance for higher education institution.

Information technology leads the public to be involved in the planning, implementation and oversight process of public policy. Many regions in Indonesia have not yet applied the concept. E-government with the application of electronic monitoring and development model, addressing the issue of information disclosure. The method is DSRM. The public can see directly every department and agency under the district government. The information displayed in the form of graphs that sort according to the achievements of each institution.

Blended learning has become effective learning mode that adopted by well known universities around the world. Blended learning refers to combining traditional classroom learning with e-learning with the aims to enrich entire learning process. From the last decade, we have seen the strong growth of millenials students in Indonesian higher education institutions. They developed high familiarity with Internet technology, social media and smartphone uses. The needs of adopting social media into blended learning has become essential part in blended learning mode nowadays. For this reason, the article takes a popular method, Virtual Learning Environment (VLE) enables to enrich the entire e-learning environment. We apply the VLE dashboard with adopting the Web-based Synchronized Multimedia Lecture (WSML) framework that enables to provide authoring tool to record the temporal and spatial relationships among media involved and facilitate synchronize presentation across media access. This framework has advantages to promote the real-time collaboration amongst students and teacher(s), like in a classroom setting, but with online mode. VLE takes advantages of web 2.0 and social media technology that enables to conduct real time meeting with video conference and easy exchange multimedia files. The outcome of the article is expected to provide social media learning based system that can be apply in higher education institutions to avoid boredom in traditional blended learning.

Cryptography is a science that studies how to keep data or messages safe when sent, from sender to recipient without interference from third parties. This paper presents a comparison of cryptographic algorithms of simetris keys and asymmetric keys. Cryptographic research related journals are collected and analyzed to find the correct comparison of cryptographic algorithms to implement. The results of this study, namely: symmetric and asymmetric keys have differences in the process of encryption and decryption. There are many cryptographic algorithms that can be applied to symmetric and asymmetric keys, but the selection and use of certain algorithms cannot be said to be forever the best because they depend on the circumstances encountered in developing the applied system.

The purpose of this research is to assess the performance of lecturers in teaching by using artificial neural network backpropagation. The tests were performed using Mathlab software that was tested with some forms of network architecture. The best architecture of artificial neural network (ANN) used is with architectural model 8-3-3-3-2. In the hidden layer used logsig activation function, and in the output layer used pureline activation function. In the first and second hidden layers using Nguyen Widrow weight initialization, the value of learning rate is0.1, error tolerance value is 0.001, with the maximum epoch is 3094 during training. With this 8-3-3-3-2 model ANN can recognize training data and test data up to 100% according to the desired target.

The aim of this study was to determine selected project executor based on multicriteria decision making. Analytic Hierarchy Process (AHP) is applied for selecting chosen project. The global priorities were obtained based on relation criterias respect to alternatives in order to select the best one. Next, a new approach for solving optimization of chosen executor project is developed that is lexicographic goal programming by zero one method. By an illustrative example, that is found the method is efficient in reaching solution. Final result showed the Ltd. A is the best chosen project. For each criteria this model enabled the decision maker to choose the optimal solution.

Along with the development of information technology today, the development of information systems is also increasing. Organizations and personal competitions to make an information system. A reliable information system is produced by a team that has the ability to design, design and validate. With the increasing number of students at XYZ College and limited existing building facilities then one of the solutions that will be applied is the development of e-learning system to support teaching and learning activities. One important element in project management is determining the organizational model to be used. The purpose of this study is to determine whether the organization model is effective to manage the e-learning system project in the PT. The research method used is literature study and interviews with key stakeholders, especially leaders of universities. The results show that the effective organizational model for the blended learning information system project is to use functional organizational structure, since functional organization is more appropriate for small to medium scale projects, focusing on the division of tasks based on the function of each part, the difficulty level is low and the limitationof resources.

Image can be presented in graph or grid graph. Segmentation is widely used in computer vision. Image segmentation is done in various approaches. One approach to image segmentation is the use of a minimum spanning tree. Almost every method of determining disparity in stereo vision uses image segmentation. The method in this paper is in accordance with the method of Segment-Based Stereo Matching using belief propagation and self-adapting dissimilarity measure with improvements for segmentation, and apply local window-based matching steps. The disparity calculation method built with minimum spanning tree approach is one alternative that can be used to calculate disparity for image pair with simple stereo configuration.

This study aims to determine the value of soil layer resistivity and then relate to the feasibilityof the construction of high rise buildings in the coastal area of Kahona, Central Tapanuli Regency. Based on resistivity value analysis this research using Geoelectric Method of Schlumberger Configuration. Variations of the type resistivity values will be obtained if the distance of each electrode is changed, then obtained the value of resistivity types that are not real values but in the form of apparent resistivity. The data obtained using the resistivity meter ARES-G4 v4.7 SN: 0609135 of apparentresistivity, then converted to resistivity value. The data obtained is made into two dimensional cross section model image using Res2Dinv software. The results showed that the coastal area of Kahona has a low resistivity value of about 4.84 Ωm to 105 Ωm on the first track and 0.865 Ωm to 165 Ωm on the second track. Based on the resistivity value obtained, the area contains clay at depths of 1.25 - 28.7 meters. Based on the results of this study the coastal areas of Kahona can not be recommended for the construction of high-rise buildings because therehard layers in the structure of subsurface rocks. Measurement of the resistivity value of each path has an error percentage of 23.6 - 24.2%.

Generic requirements of ISO 9001 make it applicable to all types of organizations including SMEs. However not a few of SMEs are not able to obtain recognition or certification from ISO 9001. Problems faced by SMEs are lack of capital and access, limited human resources, low knowledge and skills to weak business networks and market penetration ability is alleged to be the cause. This certainly does not mean that SMEs are not able to apply ISO 9001. In the initial survey research, researchers found some SMEs took the initiative to successfully obtain certification. This study aims to examine the level of readiness of SMEs in the application of quality management system in terms of socio-technology. The research method used is survey with descriptive quantitative approach. The results showed that overall the level of SME quality culture is still relatively low with an average score of 2.15. This means that the level of readiness of SMEs in the implementation of quality management system is also said to be low. Some principles of quality management have been done but still far from ideal conditions where quality aspects have not been a priority of SMEs.

Internet users in Indonesia are growing every year. Along with the development of the internet, the development of online shopping activities also evolved over time shifted some direct transaction activities. Based on the results of calculation analysis using SPSS for windows version 20 can be explained that the results of direct impact test on this research model showed the results of positive and significant influence. All X variables have an influence on variable Y. Based on this, the researcher suggested to add and maximizing innovation in generating features related to transaction security, ease of use, and risk perception in order to maximize consumer buying interest.

Modifications to Vigenere cipher are possible to make in order to be effective and efficient of this algorithm. In this study, we tried to modify Vigenere by exploiting RC6 key expansion to generate new keys used for encryption process, RC6 is a well-known as a modern cryptographic algorithm. If the RC6 Key expansion process will generate the S key as much as 2r+4, in this research will produce S Key as long as the plaintext length. Then for the encryption process done twice. The results show that the method proposed producing completely different key sequences (not repetitions like Vigenere cipher) can also produce an average avalanche effect of 17 bitsof the total 64 bits or about 26,56 %, better than the standard Vigenere which only reached 7.81%, but unfortunately no better than Vigenere with the RC6 key expansion without twice encryption process that reaches31.25% and of RC6-8/5/b with 35.94%.

The purpose of this study is to determine and analyze the influence of supply chain management against consumer loyalty supermarket Maximart Thamrin Plaza Medan. The research method used is descriptive analysis method and simple linier regression analysis method which is statistically processed with SPSS version 16.0 for windows, that is with F-test model, t-test, and coefficient of determination (R2). Researcher take sample by purposive sampling method, that is sampling technique by using certain criterion or consideration. The result of determination coefficient of determination (R2) adjusted (adjusted R square) is obtained value equal to 0,105, it means that free variable of supply chain management able to explain 10,5% of influence to dependent variable to self-service loyalty Maximart Thamrin Plaza Medan, while the other 89.5% is explained by other variables.

Affinity Propagation (AP) is exemplar-based clustering algorithm, this algorithmdoes not require prior knowledge of the number of clusters. The quality of clustering results is highly dependent on the "preference" value. Standard AP algorithm take "preference" value based on median or minimum value of similarity matrix, then the value is shared to all "preference" value on similarity matrix. This method does not give the best solution, because the value not represent the overall data structure. The Modified AP (M-AP) is proposed to resolve this problem. M-AP algorithmtake "preference" value based on data distribution on each row from similarity matrix. Experimental result show that M-AP cat outperform AP in quality clustering result based on Silhouette Index score.

Computer and web security system is an attempt to avoid attacks from crackers because a form and method of crime on internet network can not be predicted. Therefore, we just keep trying to use various methods in securing the system that is running. It is the same in web testing that can be accessed online by people who are not responsible from along distance to change and remove the test results or even damage the web testing system. So, the purpose of this paper is to design and implement web security testing system by using semantic comparison method to avoid structured query language injection (SQLI) attack and to do security on web testing application using Message Digest 5 encryption (MD5). Research data were obtained by using direct observation and documentation and literature review. After the design and application of the system, it can be obtained that by using semantic comparison method in web testing can prevent the occurrence of SQL injection attacks and can secure account from web testing users by using MD5.

Become data security issues very important when the computer has been used as a means of communication in the global network (internet). One method that is popular enough to secure the data from the irresponsible are text-based steganography, where the data or confidential information hidden or embedded in other text media so as not to arouse suspicion from the other party. Model text insertion is done is based dictionary based, which consists of 7 classes of words that correspond to the pattern of sentences in Indonesian. In this study confidential information in text form successfully camouflaged into patterns of sentences in Indonesian. But in terms of the semantic content of the text has not been well understood.

Lie detection systems using voice can be detected using the Bidirectional Associative Memory (BAM) algorithm. However, the accuracy of the system by using BAM is still low, where the true detection results obtained show a small percentage and this is also influenced by the number of training voice samples. In this study, the authors propose solutions using the Viterbi algorithm in detecting lies through sound. This research carried out the process of introducing and training lie voice samples on the word go, walk and move and then tested by simulating it in the exercise data and test data to generate the percentage of recognition and classification of the voice of the lie. The results showed that the lam detection system using the BAM algorithm has a true detection range of 67% for the word go, 72% on the word walk and 69% on the word moved. While using the Viterbi algorithm has a true detection range of 92% on the word go, 90% on the word path and 88% on the word moved. The results of this study show that Viterbi algorithm is quite effective applied to voice recognition system, can be seen from the relatively good level of accuracy and the use of low memory resources.

A priori algorithm is one of the data mining algorithm in formation of rule mining association. A priori algorithm is the process of extraction of information from a database, followed by frequent item / itemset and candidate generation in formation of association rule mining in order to obtain minimum value of support and minimum confidence value. The value of confidence has a big effect on rule the resulting, where the rule generated by the k-item sets pattern needs to be calculated on the level of confidence or certainty of the k-item sets pattern that has complied with the rules. Therefore, this research discusses about a priori algorithm modification which focuses on giving confidence value for each rule generated. Modifications are made by substituting the Bayesian method on a standard A priori confidence formula. And for the next process there is difference of confidence value between a priori standard and modification, where the value of confidence generated a priori modification is bigger, and after calculated for some rules taken according to minimum support condition then there is average difference of confidence value equal to 10,50%.

In this research, hybridization of Learning Vector Quantization (LVQ) algorithm with Self Organizing Kohonen for face recognition using webcam. Hybrid technique performed is Kohonen algorithm used for initial weighting and the result of weighting inserted into LVQ algorithm to get result of training in the form of final weight used for face recognition. The data used in this study is the face of a digital image of the acquisition with a digital tool make use of camera that will be used for learning (learning data set) and a set of images for testing (testing data set).The first step of the process the face image (preprocessing) used for prepare the input face image to be input into network. The preprocessing step in this research is divided into four step like Image Readings, Grayscaling, Sobel operator edge detection and binaryization. The result of this test is percentage of face recognition success with LVQ algorithm is 57.03%, Kohonen is 52.59% and Hybrid is 68.88%.While the average time of the introduction process is for LVQ of 2.64 seconds, Kohonen of 2.61 seconds and Hybrid 2.59 seconds. From the above results can be concluded that in terms of accuracy Hybrid algorithm slightly superior to the Kohonen is 16.29% and in terms of time Hybrid algorithm faster than LVQ algorithm of 0.05 seconds and Kohonen an average of 0.02 seconds.

Load Balancing is very well applied to the distribution of internet access at any point of the Wi-Fi area so that the use of limited devices can be optimal and on target. The proper use of the Greedy Algorithms when applied to an access point device is very capable in resolving excessive loading in a single resource to take the best choice at every stage in an optimum process. Access point device is also a success factor in running the optimization of the distribution of Wi-Fi access on the Access Point is strongly influenced by the parameters set. In this research, user access factor in one very high Wi-Fi area also influences the possibility of incoming access failure. For the application of the results of this study can be utilized on all access point devices that have limits, but for speed internet access remains at the capacity provided bandwidth.

The 802.11 networks have been commonly used for public internet access. Most 802.11 hotspots have more than one access point in an area. When these access points belong to the same network, users may choose anyone it connects to. In order to enhance the access services, some methods have been proposed. The methods allocate users to certain access point to avoid crowded and collided access. The method is referred to as load balancing. The existing work in load balancing are usually based on traffic balancing as well as cell breathing. The first one is the most common method as the cell breathing applies power reduction while electromagnetic wave travels anywhere and access point are usually in distance of low power transmitter. This paper proposes load and resource balancing where the client allocation is not only based on its load but also the access point resource. The simulation evaluation shows that the proposed method outperforms the existing one by reducing delay by 0.9%, increasing throughput up to 715 kbps and the collision probability reduces by 0.068% in average.

Security is a big issue and securing important data is so important that it can't be tapped or misused for illegal purposes to the detriment of others. Cryptography is a way used to maintain security where messages are disguised into encrypted messages. One-time cryptography pad is one type of cryptographic technique that uses substitution method by giving special terms to the key used that is made of characters or random letters (random key or pad), and the randomness does not use a certain formula. The Vigenere code includes a poly alphabetic subtitution cipher which in subtitle technique each text have many possible original texts. Super Encryption is a method of combining between the two algorithms that aims to get a stronger cipher making it very difficult to solve. The result of this research is the process time stated that the average time of plaintext encryption process with 50 characters is 3 milisecond while the mean time of plaintext encryption process with 100 characters is 7.33 milisecond. Then for the average time of encryption ciphertext process with 50 characters is 75,333 milisecond while the mean time of ciphertext encryption process with 100 characters is 132,333 milisecond.

Cryptography is a science to keep information secure, including encryption process and description. There are four fundamental objectives of cryptography that are aspects of information security: confidentiality, data integrity, authentication and non-repudiation. The ElGamal algorithm is one of the most secure algorithms because it has a high security in algorithm complexity. The ElGamal algorithm gives different ciphertext each the plaintext is encrypted. The LUC algorithm is one of the variants of the asymmetry cryptography algorithm. The LUC algorithm uses two primes to generate public keys and secret keys. The LUC algorithm has much in similarity with the RSA algorithm but in the LUC algorithm the ranks function in RSA is replaced by the Lucas function. Super Encryption is a method of combining between the two algorithms that aims to get a stronger cipher making it very difficult to solve. The result of this study is the process time stated that the average time of plaintext encryption process with 10 characters is 7.33 milisecond while the mean time of plaintext encryption process with 100 characters is 134 milisecond. Then for the average time of encryption process ciphertext with 10 characters is 47,33 milisecond mean time ciphertext encryption process with 100 characters is 186,33 milisecond.

File security is very important in maintaining the confidentiality of the information contained in the file. For that we need a way for information to be kept secrecy, that is with the science of cryptography. Cryptography is one method that disguises data to form encrypted data. In the symmetric RC4+ (Ron Code or Rivest's Cipher) algorithm, it provides secure message security and is an efficient stream cipher. RC4 NGG stream cipher algorithm 3-5 times faster than RC4 algorithm and but still have weakness in KSA randomization. The RC4 GGHN stream cipher algorithm is based on the RC4 algorithm and is relatively more efficient but still has weaknesses. Based on literature review from several research sources, it was stated that RC4+, RC4 NGG, RC4 GGHN are algorithms that are faster and more efficient than RC4 algorithm. Therefore, it is necessary to compare the encryption process with the aim of comparing and knowing which algorithm is better from running time and algorithm complexity. In this research we will perform two tests on each algorithm, image encryption using different key length and same image size and image encryption using the same key length and different image size. The results obtained in this research is RC4 NGG algorithm is the fastest algorithm between the three algorithms that is 13.3% faster than RC4+ and 10.2% faster than RC4 GGHN where the key lengths used in encryption do not affect the processing time and image size used in encryption very affects the processing time.

The mobile device miniaturization requires the applied antenna microstrip size be much smaller to reduce the radio front-end load. This paper discusses the rectangular patch microstrip antenna miniaturization by using complementary split ring resonator (CSRR) structure for 3G mobile communication system on 2.1 GHz. The structure is implemented on the microstrip ground plane. Simulation evaluation by using the AWR simulator shows that the CSRR structure is able to reduce antenna dimension about 62.71% from 3192 mm² (56mm×57mm) to 1190 mm² (34mm×35mm). Beside miniaturization, VSWR and return loss also experience improvements about 1.05 and -33.83 dB subsequently. Bandwidth increment about 70.37% is also achieved.

K-Means is one method in data mining that can be used to perform grouping clustering of data. Accurate data processing can be done by processing the data source. Each collection or data warehouse can provide important knowledge into valuable information, constraints on this method, if the cluster point is chosen randomly so that the resulting data may vary, if the value is not good, then the resulting grouping is less than optimal. Furthermore, failure to outliers in the process of grouping data include determining whether a data item is an outliers of a cluster of course and whether small amounts of data form a separate cluster. where the gain ratio is used to calculate the attribute's influence on the target of a data gain ratio is the development of the information gain, where the gain ratio eliminates the bias value of each attribute. The result of the research is to calculate the weights in each attribute by using the gain ratio and make the modeling and classification into the method of K-means.

One of the concepts of E-Ticket Bus is the application of information technology to simplify process of public services so that it can help public service users and have an important for government and entreprenuers. Bus is an important public transport. Bus is an important transportation of metropolitan residents. The urbanization process becomes faster than usual. In this case the payment of bus tickets on buses station of located in Medan, especially for the city of destination Medan-Banda Aceh is still using the ticket paper. Traditional way like this has a weakness, because the passengers have to queue up 2 times, which is queuing at the ticket purchasing counter and queuing at the bus entrance. From this research will encourage bus companies, especially in Medan to include E-Ticket for Bus in the existing service to repair and improve transportation services. Mobile of E- Bus was developed to help passengers to order tickets by mobile. The business model built can provide benefits for the company, and passengers. Transportation services can be made available to users anywhere, anytime and any device in booking bus tickets.

In this paper, From the results of the study it can be concluded. A different target error will produce a different number of iterations. The smaller the target error, the greater the number of iterations. The smaller the target error, the better the accuracy value (the greater). The number of iterations in the training process with variations in momentum values is smaller than without variations in momentum values. The highest level of accuracy is achieved at the target error of 0.001 with a momentum value of 0.4 which is 96.62%.

This competency test application was developed using the Waterfall Model with the help of software such as XAMP server, PHP, MySQL, JavaScript, Hypertext Markup Language and Cascading Style Sheet for template design. The development of this application using a Waterfall model defines several phases and must be completed one by one to move to the next step. Waterfall model is recursive because each stage can be repeated without stopping to perfection. This advanced application is handy for students and lecturers. The students can directly see the final results and print them into PDF documents in the form of the report after completing the questions. These test results can be used to evaluate the learning process and predictions on the competitiveness of alumni.

Information is very important to the existence of something. The information space in this case becomes a continuously explored presentation and determines the existence of something. However, that existence must be related to the access tool, the search engine, serving as an intermediary. Not a few search engines have been present, each having different behaviour. This paper reveals the role of search engines based on singleton through logical reasoning and the set concept. While some measurement results have showed how the concept is played by search engines.

By using Web, information contributes to existence of relation. The information space take a position for exploring presentation and determines the existence of relation. However, this existence depend on the access tool, the search engine. They are as interface for it. A search engine has itself behaviour. This paper express the role of search engines based on doubleton through logical reasoning and the set concept. While a similarity showed the relation is exist.

Companies carry out the production process always facingthe market competition. The process is done on the production floor is required to produce a quality product and capable to win the competition. Machine condition greatly affects the production process. A good machine will produce quality products, otherwise the engine in not good condition will produce anunqualified product as well. Companies engaged in the field of pharmacy manufacture often sufferingmachinery damage where the damage to the engine is mostly caused by the machine components of failure the function and the machine cannot run the process of operation When there is damage to one of these machines on working hours of the machine, then the production process will be disrupted because it takes a time to replace the engine components. Therefore, it is necessary to analyze the machinery damage by identifying the critical components causes of machinerydamage and corrective action is done immediately. The study was conducted using the 80/20 pareto rule with minitab software. The results obtained with the pareto rule shows that the percentage of machines often damaged is a tablet machine with a percentage of 40% while the components that the main factors of damage to the tablet press machine is a component of punch and dies and pulleys.

A lawn mower is a machine used to mow grass or plants. This machine is commonly used to tidy up the garden and also to clear the fields from grass or other types of grass. The commonly used lawn mowers are made of thin, hard and very sharp iron plates, so they can easily mow the grass. In the process of making the design of this lawn mower product, we first use the technique brainstorming to determine the characteristics of the product to be made, then draw conclusions from the brainstorming that has been collected. The technique is then carried out sampling by distributing an open and closed questionnaire to determine the type of product. After the open and closed questionnaires were finished, the conducted survey was market using technique sampling, and determined the validity and reliability test of main product with competitor product I, competitor II and competitor III. The step problem to the sub problem is determined to classify the objectives to be made on the design of the lawn mower products. The step sub-problem to the sub solution is performed to determine the Quality Function Deployment (QFD) of the product. The step sub solution to the solution is determined to generate and evaluate alternatives with the sum of matrix pairs between attributes.

Portable medical devices are becoming more common. The article considers the possibility of using an artificial neural network for counting blood cells on a microfluidic device. The proposed system is based on recording the absorption and scattering of light, when cells pass through the channel. The neural network was trained on samples containing only one type of cells. The ANS study was conducted on whole blood and diluted samples. The results obtained show that the number of errors admitted in the classification of leukocytes is much greater than necessary for practical use. Additional sample preparation significantly reduces the number of errors in the count of white blood cells. The classification of erythrocytes and platelets with ANS was satisfactory.

This research was conducted to test the effectiveness of antibacterial inhibition of galangal (Alpinia galanga L.) on the growth of Escherichia coli and Bacillus subtilis bacteria with concentration 0%, 15%, 30%, 45%, 60%, 75%, 90%, 100 %. The method used in this study with the Kirby-bauer disc diffusion method with 0% concentration as negative control. The results showed that galangal (Alpinia galanga L.) at 100% concentration had the highest inhibition area in Bacillus subtilis (1,13 mm) and E. coli (0,8 mm). Galangal has more effective antibacterial activity in Bacillus subtilis bacteria than E. coli.

One of the efforts in improving the degree of health is more optimal with the fulfilment of the need for hygienic food. The objective was to analyse the correlation of the hygiene and sanitation of food handlers to E.coli contamination to find the factors which have the strongest correlation with E.coli in the foods in three canteens of a university. This study applied the descriptive observational which cross sectional design in canteen food stalls. Observations were carried out at all food stalls and interviews were conducted to 32 respondents consisting of food handlers. Statistical analysis used Chi Square test. The results show that positive E.coli contamination on canteen food (canteen campus 1, 2, and 4) was 25 (71.43%). The independent variables that have significant relationship with E.coli contamination on food cafeteria are food ingredients OR = 1.203, ingredients food storage OR = 0.000, food storage OR = 0.000, food carrier OR = 0.000, food serving OR = 0.000, building construction OR = 0.000, sanitation facility OR = 0.000, building construction OR = 0.000, sanitation facilities OR = 0.000, and food handler OR = 0.000. While the most influential independent variables on E.coli contamination on food in canteen campus is variable food ingredients OR = 1.203 and food processing OR = 3.800.

Preeclampsia is a major cause in both maternal and perinatal mortality and morbidity. The etiopathogenesis of preeclampsia is still not fully elucidated but it is believed to be a multifactor. It is assumed that preeclampsia is caused by oxidative stress in placenta which cause endothelial and vascular dysfunction. In vitro model research is considered the best and most effective way to understand the disease pathophysiology. Phaleria macrocarpa (Scheff.) Boerl also known as Mahkota Dewa is widely used as an antioxidant because of alkaloids, saponins, flavonoids and polyphenols properties. The phenol and flavonoid compounds have antioxidant and anti-inflammatory activity. This study aimed to determine Phaleria macrocarpa extract's LC₅₀ in fibroblast cell primary culture. The LC₅₀ was measured based on Brine Shrimp Lethality Test (BSLT) method. The LC₅₀ of Ethyl Acetate fraction of Phaleria macrocarpa extract was 38.16 ppm and the LC₅₀ of N-Hexane Fraction of Phaleria macrocarpa extract was 157.91 ppm, both measured at 550 nm wavelength. Phaleria macrocarpa extract's LC₅₀ obtained later can be used as reference in subsequent research using trophoblast cell and HUVEC cultures. Further studies regarding the optimal dose of Phaleria macrocarpa extract for clinical trial are encouraged.