Table of contents

It is with great pleasure that I introduce the proceedings of the 2^nd International Conference on Advance Engineering and Technology (ICATECH 2020) is an international seminar organized by Institut Teknologi Adhi Tama Surabaya (ITATS). ITATS is private university located in Surabaya, East Java, Indonesia. The conference is held on September 26^th 2020.

This seminar has the main purpose to bring researcher and scholar to share their knowledge and experience in Material, Metallurgy, Energy, Design, Engineering, Applied Science, Information System and Technology area. The conference serves as an excellent opportunity to meet each other and to exchange ideas with theme of "Empowering Research and Innovation for Sustainable Technology".

The conference is initially planned to be an offline meeting in the venue, but within the outbreak of COVID-19, it is changed into a virtual conference instead of being postponed. The conference is organized through online virtual mode using Internet Communication Technologies (ICT) via Zoom. Authors shared the screen and attendees could discuss their work via online platform. Overall, the conference was held successfully through the platform. Our conference committee and authors were dedicated to support the success of the seminar.

List of Editor, Keynote Speaker, Organizing Committee, Scientific Commiittee 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 Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing.

• Type of peer review: Single-blind with two level review system

i. The conference editor reviewed the submitted papers relevance to the conference topics, checked whether the papers meet the IOP format requirements, and doing similarity check to ensure the percentage of similarity is not greater than 25%.

ii. The independent reviewers evaluated the submitted papers according to the following criteria as the relevance to meet the substance of study, novelty of work, quality and scientific knowledge, and adequate references etc.

• Conference submission management system:

All the papers were submitted via EasyChair link and conference Email.

• Number of submissions received: 73 submissions received

• Number of submissions sent for review: 73 submissions were sent for review

• Number of submissions accepted: 66 papers accepted

• Acceptance Rate (Number of Submissions Accepted / Number of Submissions

• Received X 100): 90

• Average number of reviews per paper: 2

• Total number of reviewers involved: 16

• Any additional info on review process: -Nil-

• Contact person for queries:

Syamsuri, ST., MT., PhD.

Associate Professor

Phone: +62 819-3828-8275

Institut Teknologi Adhi Tama Surabaya

Gedung A Lantai 1, Kampus ITATS

Jl. Arief Rachman Hakim 100, Klampis Ngasem

Surabaya, Jawa Timur, Indonesia 60117

E-mail: syamsuri@itats.ac.id, icatech.support@itats.ac.id

Website: http://icatech.itats.ac.id

The propeller shaft is part of the ship which transmitting rotation from engine to propeller. The shaft is also used in small-medium size of fisherman boat. In order to reduce the cost of production, dissimilar metal bases are used by joining Steel ST41 and 316L Stainless Steel in process. This research was conducted to analyze effect of welding electrode towards tensile strength, macrostructure, and microstructure of Steel ST41 and 316L Stainless Steel welded metal. Two variations of electrode that used in this paper were E309-L and E6013 with Shielded Metal Arc Welding process (SMAW). The other parameter such as current was set at 80 A and voltage was set at 20 V with 20 mm/min welding travel speed. The results of tensile test show average tensile strength max (σ_max) of E309-L and E6013 electrode were 581,42 MPa and 599,24 MPa respectively. These results show that welding process is increasing the maximum tensile strength from base material strength level. The microstructure test interpretation shows E309-L electrode has lower possibility to create delta ferrite in HAZ (Heat Affected Zone) rather than E6013 electrode. This means welding process with E6013 tends to have lower corrosion resistance.

Many automotive companies are adding new devices and features to the latest generation of cars. Some changes such as the addition of an adds-on device and car design lead to changes in the aerodynamic characteristics of the vehicle. this study will be carried out on the changes in the aerodynamic properties of the 3 generations of Model cars: Model 1, Model 2 and Model 3 in 2 D Steady state simulation. The car simulated in various numbers of velocities in 40 km/h, 60 km/h, 80 km/h and 100 km/h. The characteristics of aerodynamic force around the car are discussed in this paper from the qualitative and quantitative data. The quantitative which used as measurable data are Coefficient of drag (C_D). Quantitative data has better visual explanation of the stream characteristic. The qualitative data which used in this paper are path line and velocity contours. The validation process is conducted with the previous research and the average error was 5%. The results showed that Model 2 has the most aerodynamic design than the other type due to the drag coefficient was lower than the other type.

The objective of this study is to obtain an enhanced understanding of the effect of diesel spray/flame impingement on transient heat flux to the wall. By using a constant volume vessel under engine-like condition, surface heat flux of the wall at spray/flame impingement was measured with three thin film thermocouple heat flux sensors. Fuel was injected using a single-hole injector with a 0.133 mm diameter nozzle. In order to investigate the relation between diesel flame and wall heat loss, two color-method was applied to observe flame temperature distribution. 21 % and 16 % as the various oxygen concentration were investigated at each injection pressure of pressure 80, 120, and 180 MPa. The results showed that the lower oxygen concentration was generated heat loss regardless of injection pressures. The lower flame temperature and flame contact area and period were influence factor on heat loss on the wall. Furthermore, the relation between Nusselt number (Nu) and Reynolds number (Re) were also investigated to understand the heat transfer phenomena in diesel engines.

Mostly geothermal power plant placed around volcano on land. Sangihe Archipelago, the northern of Sulawesi Island known as volcano arc that formed by the subduction of Philippines plate beneath Micro-Sunda plate. The geothermal source is located under sea level, this condition needs some approach of remotely applied sciences. The possibility study is conducted by bathymetry, gravity, magnetic, and regional geology. The objective is searching the high value gravity at the high topography as indication of the magmatic product on the seafloor and the low value of magnetic as indication of the active heat resources. A profile section from Philippines oceanic plate to the Celebes Sea by using each data shown a sequence of subduction product, such as trench, outer-arc ridge, and volcano arc. Geological data is used to know the evidence volcano arc and outer-arc ridge. The volcano arc shows that the age is around Quarter which means it is possible for geothermal resources, the outer-arc ridge shows that the rock contents were melange complex and ultramafic rocks. Sangihe area has possibility for further research as geothermal offshores.

As one of the most efficient biomass conversions, the gasification process is hard to understand because of its complexity. A simplified gasification process simulation using a zero-dimensional model was designed for an empty fruit bunch considering its potential in Indonesia. A stoichiometric equilibrium model was applied to simulate the whole gasification process. Global gasification reaction, mass, and energy balance with two independent chemical reactions are integrated to perform the model. Some sets of linear and nonlinear equations were solved with the Newton Raphson method in Matlab. The output of the model, like syngas composition and the heating value, was validated with available experimental data published. The zero-dimensional thermodynamic equilibrium model could be used to predict the maximum performance of the gasifier and make the gasification process more feasible.

Comfort and good handling are always a problem in conventional passive suspension systems. The ideal suspension criterion is to have a short time response, have a small amplitude and eliminate the frequency of causes of motion sickness. The system is only obtained with an active suspension system. The active suspension has an actuator that is able to produce a force to reduce the dynamic force of the vehicle. This actuator will be controlled by a PID active control. The test results showed that the active control was able to reduce the amplitude by 18 mm, passes the Sickness motion frequency and can return to the set point in 0.8 seconds.

Pile foundations are often required to resist lateral loads and moments in addition to their primary use as axially loaded members. The interaction between material strength of axial, moment and shear against load capacity and soil interaction is the most important factors in the pile analysis. This study aims to obtain the lateral bearing capacity of pile foundation using a spring modelling system which will be calculated manually for the K_v spring constant in the vertical direction and the k_h coefficient in the horizontal direction using the Nakazawa method and SAP 2000 v14.2.5 program. The result shows that the maximum shear load and the maximum axial tensile load received by the pile is still within the allowable shear load and allowable axial tensile load capacity resulting from the manual calculation. However, the maximum axial compression load and maximum moment is exceeded its each allowable capacity. Hence, it is necessary to re-modelling by adding the depth or number of piles.

The information technology used by companies today is ERP (Enterprise Resources Planning) technology. This study aims to examine the role of ERP compatibility in improving the performance of MM-2100 manufacturing companies. Data is collected at manufacturing companies that have made ERP system adjustments. Data collection was carried out through questionnaires distributed to manufacturing companies, and as many as 78 questionnaires were obtained, which could be further processed. Retrieval of data using questionnaires submitted to the relevant section that has access to company inventory data. Data analysis was performed using the SEM-PLS technique using smart PLS software version 2.0. The results of the study show that ERP compatibility can increase internal information integration and inventory system continuously. However, ERP compatibility has no direct effect on manufacturing performance. Internal integration affects inventory systems and manufacturing performance with coefficients of 0.346 and 0.378, respectively. Internal integration allows other functions to be able to access inventory in the company. The company's inventory system that is controlled can perform efficiency and effectiveness for the company so that it has an impact on manufacturing performance with a coefficient of 0.766.

information systems have become inseparable from current products and services. Improving information systems will add value to the quality of products and services. Some references can be used to produce a good information system. One reference that can be used is ISO 20000-1: 2018. Because of the new standards, there are not many studies that guide the implementation. This paper aims to contribute in providing references for application in aspects of information system planning based on clause 8 ISO 20000-1: 2018. The modelling process uses SysML modelling language. We find the guidance to implementation of this standard and the example of Model Based System Engineering using Block Definition Diagram.

Vehicle Routing Problems (VRP) are a type of linear programming problem. This paper tries to explain the completion of VRP using Python Programming with the Simulated Annealing algorithm. Python Programming is used as a tool by utilizing the wealth of packages in python. Python is a popular programming language. Python is easy to learn for beginners. However, there is still no example and guide for solving VRP using simulated annealing in python programming with a process paradigm. This design can be a reference and guide for beginners in dealing with similar problems or the development of existing problems.

Body Area Network is a measurement concept using sensors with a pair directly attached to the body to monitor the condition directly. The benefits in the world of health are enormous plus remote monitoring capabilities. Currently the use of medical devices as a means of detecting heart conditions, blood pressure, and so forth is still considered less efficient, because in every health tool required several sensors and different platforms. Thus, the idea for integrating these sensors is to improve service quality and tool efficiency and time, to meet the Body Area Network concept, this research proposes a new approach to direct health monitoring. The purpose of this research is to integrate some medical devices such as Temperature, Electrocardiogram (ECG), Electromyogram (EMG), Galvanic Skin Response (GSR) and SPO2 Pulseoxymeter into one platform portable health sensor equipped with two delivery media for data storage that is by using Bluetooth and network Wi-Fi so that in a health check only use one tool. In the application of the results of the use of GSR, ECG and EMG sensors in the form of graphs that can be seen fluctuations based on measurements in the body, and on the use of temperature sensors and SPO2 Pulseoxymeter results from visualization on the sensor in accordance with the measuring value range in normal body.

Data is a critical component in the management of systems that support business in an organization. The application of proper data quality management can help organizations in making policies and maintaining data by reducing inconsistent data. The initial stage in the data quality management process begins with the profiling process. The use of job trigger executors in DQM applications affects the application performance level. This paper aims to make changes to the executor used by using a carte server to improve the performance of the DQM application that has been made. Carte server is a web server that allows running files remotely. The results of this study will compare application performance from the use of different executors namely job trigger (pan.bat) and carte server to find out which is superior. With that knowledge can be obtained about the importance of performance in the application.

This study discuss 24-hours load scheduling to get the minimum generation cost. Fuel cost in load scheduling need to be considered, because fuel and power suppliers are bound by take or pay schedule. In addition load scheduling considering heat rate, start-up cost, minimum up time and minimum down time. Load scheduling calculate by priority list method that is completed using artificial intelligence, Binary Particle Swarm Optimization (BPSO). The data used in this study is IEEE 30 bus and Java-Bali 500 kV.

Currently, much research has been done to develop routing algorithms to improve the lifetime of sensors from Wireless Sensor Network (WSN). Routing protocols based on the network structure can be classified into two categories: flat protocols and hierarchical protocols. One of the most popular hierarchical protocols is the Low Energy Adaptive Clustering Hierarchy (LEACH) algorithm. However, LEACH routing has a high packet loss in a busy network. This research propose Two Layer LEACH based on area Partition (TL-LEACH-P) routing algorithm based on the LEACH routing algorithm where the cave layer is done to prioritize the node that can become Cluster Head to decrease energy consumption. LEACH and TL-LEACH-P algorithms are simulated using MATLAB. The results show that the TL-LEACH-P algorithm has a better performance of 60% reaching LEACH in terms of network lifetime. The TL-LEACH-P algorithm has a 50% increase in the round where 50% of the nodes are dead from LEACH. Best TL-LEACH-P algorithm performance is when the k cluster value = 5. And best performance for LEACH algorithm is when the k cluster value = 15.

The design of the exhaust system affects many parameters such as reducing the noise level, control velocity, temperature, back-pressure of exhaust gas and reduce pollution production. The exhaust system has many parts which consist of an exhaust manifold, resonator, catalytic converter, muffler, and connecting pipes. Muffler has the main function as a noise absorber. Furthermore, the temperature distribution on mufflers is also affected by fuel consumption by reducing back-pressure effect. This study has conducted an experiment to determine the effect of modified muffler shape in a motorcycle which consists of standard, scorpion, and 3v3 type. The effects of mufflers' performance on the motorcycle are described on torque and power graphics. Furthermore, this study explains the muffler geometry effect on noise reduction from the combustion process. The installation of 3v3 muffler decreases torque and power in a motorcycle. Moreover, the installation of 3v3 muffler type raises noise pollution level which generates by the engine combustion process.

This research was conducted by laboratory-scale trials to make activated carbon from empty oil palm bunches. Empty bunches were palm oil processing industrial waste. This research was an effort to optimize waste management. Empty palm oil bunches were studied to become carbon active. Activated carbon is needed to meet the needs of the food industry and non-food industries. This research aimed to determine the appropriate method, optimal operating condition, and get the specification of standard carbon active. Making activated carbon was carried out by multiple activations; chemical and physical. The feed carbonation process was conducted at 400° C for 4 hours with N₂ gas flow. After the charcoal is formed, chemical activation is carried out using an H3PO4 activator with a concentration of 9-15% wt. Physical activity was conducted by heating the activated carbon method in 700°C for an hour. The result of the study showed that multiple activations produced activated carbon, and the quality filled the standard. H₃PO₄ concentration of 13% was the most appropriate concentration to provide activated carbon with the best quality. The best quality activated carbon, which has produced of this research has complied with Indonesian National Standards 06-3730-1995 with parameters: 3% moisture content, 3.92% ash content, 0.7% volatile matter, 95.38% bonded carbon, iodine number 945.47 mg / g, and surface area of 272.9 m₂/g.

In the traffic environment, accidents often occur due to road conditions with holes. This can be fatal for motorcycle riders and car drivers. Therefore, this paper aims to provide a road contour damage information system by detecting potholes on the highway and reporting damage on Google's maps. So road users, especially vehicle drivers, can be careful when they want to pass that road. The method used in this paper, which uses Werner D. Streidt algorithm threshold values and edge detection in digital image processing to detect holes in the road, as well as mark the coordinates of hole locations and uploads them on Google's maps, using the Raspberry Pi two embedded devices as a management center data, with a 6M NEO U-box Global Positioning System (GPS) sensor, as geotagging location and CSI camera interface. A A raspberry pi 2 for taking pictures of road surface contours. System testing is carried out in several stages at different times. In daytime conditions, in sunny weather, the system's success rate in detecting potholes is 83.2%. Whereas with tree barriers, the success rate is 67%, with detection failure 33%. In conclusion, this system succeeded in showing all points of the hole location by giving a mark on the Google Map display application.

Austenitic stainless steel types of SS304 and SS304L are most widely used in the industrial manufacturing because it has excellent weldability and corrosion resistance. It is undeniable that welding is one of the common steps in the manufacturing process and repairing damaged equipment. In this study, three different welding methods including TIG (Tungsten Inert Gas), SMAW (Shielded Metal Arc Welding), and MIG (Metal Inert Gas) are described to compare mechanical properties and morphological analysis. The characterizations were conducted by tensile test, XRD, and Metallography. The results of this study indicate that MIG causes higher tensile strength compared to TIG and SMAW, the highest tensile stress value occurs in SS304 material with MIG welding of 679.64 MPa, while the lowest tensile stress value in SS304L material with SMAW welding of 604.89 MPa. Based on microstructure analysis, Both materials present austenite, ferrite, and Cr carbide phases.

Queues are waiting for lines from customers to get service. The queue is caused by the needs of consumers to be served beyond the ability of service facilities, so consumers who come cannot immediately get service. Queue problems at ports often occur every day. Ship loading and unloading services is a queuing phenomenon in daily life. This queue can be caused by damage to the equipment that supports loading and unloading, labor, availability of warehouses, and the limited capacity of berths at berths and others. In maintaining optimal port services, it is necessary to avoid long waiting times and low queuing system utilities. Queues at the mooring service system occur due to mismatch between planning and realization. Waiting time for vessels inside and outside the port area is calculated using the simulation method in queuing theory so that it becomes a queuing model. Until finally, it produces the optimum berthing service system. Based on the simulation results obtained value, and which is much shorter than the conditions on realization. The potential causes of these conditions are divided into three factors, namely, internal factors, external factors, and weather factors.

Amid the Covid19 Pandemic, the world is currently experiencing a difficult time. The impact of the chain due to soaring crude oil prices on world markets has been felt by all levels of society. Responding to this, austerity movements in various sectors are needed in order to create alternative solutions to the dependence of FO to get through difficult times. In the sea transportation sector, the use of fuel for motorized vessels is not only uneconomical but also environmentally unfriendly. The dependence on fossil fuels energy has led to the development of the concept of energy efficient vessels that use alternative energy sources in moving ships. This is anticipated by the re-use of sails in the form of Sailboats (SB) which are applied as fishing vessels. This paper presents a study of the efficient use of wind energy in SB as a boat mover that does not utilize fuel for the development of environmentally friendly fishing vessels. Technical analysis is done through testing the ship model in the Towing Tank then the results are explored by Naval Architect theories. In conclusion, there is a potential savings in fuel consumption by 100% when compared to ships that have only engine-driven.

Retinal blood vessels are a very important object to diagnosing illness. Fast, automatic, adaptive, and accurate systems to segment the retinal vessels are particularly useful. The retinal blood vessels can be detected by edge detection. This research will compare the edge detection techniques with adaptive ant colony optimization (Adaptive ACO). Generally, the early ants on the conventional ant colony optimization (ACO) are randomly distributed. This condition can cause the ant distribution imbalances. Based on this problem, the ant distribution modification on ACO is proposed to optimize the ant placement based on the gradient. The gradient values are used to determine the ants' placement. The ants are not randomly distributed but placed in the highest gradient. The so-called Adaptive ACO is expected to be used for better and faster path discovery optimization. The average PSNR of Prewitt edges, Sobel edges, conventional ACO, and the proposed method are 11.605, 11.913, 9.783, and 15.874 respectively. The PSNR of the proposed method has the greatest value than others. It shows that the placement of ants based on gradient can improve edge detection accuracy. The application of the Adaptive ACO method has successfully optimized the result of retinal vessel edge detection.

The steel industry is classified as a strategic industry that supports many industries, due to continuous national development. The steel industry must improve the quality of its production processes in order to increase its competiveness. One factor that supports the stability of the production process is the procurement process. Delays in the procurement process can disrupt the smooth production process. The purpose of this research is to minimize waste in the steel procurement process by using the value stream mapping method. This research begins by making current state mapping of the actual procurement process, then analyzed the activity categories including value added activity and non-value added activity. In the beginning, the total time value added activity is 7488 minutes and total time non value added activity is 12240 minutes. An improvement was made in terms of the negotiation process, document review, and waiting for an offer, the result of the total value added activity is 7488 minutes and non-value added activity is 2160 minutes, so the procurement process initially 41 days became 21 days.

Tungsten inert gas (TIG) welding is one of the most popular welding which has high quality welds. TIG welding can be used for all kinds of welding positions and high efficient. During the welding process, the welding specimen and the heat affected zone (HAZ) affected by a series of thermal cycles where the area warms up to a maximum temperature then followed by cooling process. The thermal cycle affects the microstructure of the welding specimen and HAZ. By controlling these parameters to reach the right heat cycle, the mechanical property of the weld metal can be improved and maintain the microstructure of the weld metal. This study is conducted an experiment to determine the effect of different wind velocity around the TIG welding material. Moreover, this study also discuss the effect of shielding gas flow rate on TIG type welding on JIS G 3131 SPHC steel material. The welding area and HAZ the higher the wind speed the hardness value tends to decrease. Because there is a difference in cooling speed and heat input on weld metal and HAZ.

In this era, many electronics have been marketed in Indonesia. One of which is amplifier that is used to amplify the sound of MP3 player, radio, VCD or television. An amplifier is an electronic appliance that obviously has a certain lifespan or lifetime and afterwards damage will occur. Most people go to an electronics handyman to repair the damaged electronic appliance but not all handymen can analyze the damage easily. To overcome this problem, a system was setup to identify the damage of an amplifier. A damage identification on this system applied Vikor method. Vikor is a ranking method using multiple criteria ranking index based on certain measurement closed to the ideal solution. This application cloud be used as supporting consideration in talking the required steps for repairing an amplifier. The test result and calculation analysis using Vikor method obtained the system accuracy of 81.25%.

Indonesia contains of island and ocean which perform some problems in logistics delivery such as create a gap between west side and east side of Indonesia. A sea highway program were made by president to send logistics to be more effective and efficient. This program has been implemented for four years recently but still has many adjusment such as creating the best route of sea highway. This research try to create a better route of sea highway by using tour constraction to create an initial route in two steps, clark and wright saving matriks and parallel insertion. The second method is tour improvement aims to generate a new route after initial route by using exhaustive search. Five route of sea highway are generated in tour constraction and two route has been adjusted in the tour improvement because of a better score came up. The improvement of fourth route from Depot-Malahayati-Batam-Telukbayur-Depot becomes Depot-Malahayati-Telukbayur-Batam-Depot and second route still being the same but there also another option of route which has 18 score different from the best route score, those are Depot-Sampit-Samarinda-Balikpapan-Pontianak-Depot.

Bamboo is building material that is well known in Southeast Asia, which is renewable, environment-friendly, widely available and fast-growing, as other materials resource such as timber is diminishing and restricted due to deforestation. While timber demand is rapidly increasing, unfortunately, the supply is depleting. Therefore, bamboo can be suitably replacing timber and other materials in construction and other works—moreover, bamboo grown abundantly in Indonesia and easily found in each district as local material. Using local materials is essential in this fast-growing world. Local materials can reduce carbon footprint and support sustainable development efforts. Also, bamboo construction also technically eco-friendly and cost-effective with durable and have high sustainability impact. Besides, the land available for residential housing is currently running low. This problem requires innovation in terms of space effectiveness in design. As a two- or three-story compact bamboo house concerning sustainable local material. This research analyses the user configuration to proceed bamboo as local material to construct a compact house model that is green and durable. These works initiate nature sustainability buildings to fit into natural surroundings.

The calculation of ship operating costs is a major element in determining tariffs. The determination of high or low tariff is very important in the shipping business. In other words, determining the proper ship operating costs is the key to the success of the shipping business. There are several components in determining the operational costs of a ship, one of which is the calculation of fuel needed to cover a certain distance. Usually for new routes, the calculation uses the formula specified by the Minister of Transportation No. KM. 58 of 2003. However, this manual calculation requires a lot of time and human error factors will result in inaccurate calculation results. So, we need a more effective and efficient way to calculate the amount of fuel needed to cover a certain distance. In this study, a simulator was developed that uses the concept of a spherical triangle to determine the distance and direction of a ship and then integrates it with the formula of the Minister of Transportation to get the results of the fuel calculation. From the results of 2 trials using the Bung Tomo Training Ship, the calculation results were faster and more accurate. Even more, the simulator users can simply click two points as the beginning and end of the ship's journey. Thus, the simulator can simplify the process of calculating ship operating costs, especially the determination of new routes in the shipping business.

Automatic Guided Vehicle (AGV) is a material transfer tool that is now widely used in the industry. One of the advantages is that it can transfer material automatically without the need for an operator who has to drive it. AGV using a magnetic guided sensor is one of the most widely used types. So that the tool can run according to the planned trajectory, it is necessary to design a controller that matches its characteristics. The design of the controller is needed identification of the model of the plant to know the characteristics of the plant. Identification with the Extended Least Square method is a form of parameter estimation recursively through a quadratic error gradient formulation with a criterion function involving all errors. The structural approach model used linearly uses Auto-Regressive eXogenous (ARX) and Auto-Regressive Moving Average eXogenous (ARMAX). The validation process of the model uses the Means Square Error (MSE) criteria and the FIT percentage. Based on the results obtained by the best plant with ARMAX model structure with MSE values 82.14 and percentage of FIT value 89.98%.

Small-scale construction service providers dominate the construction industry in Indonesia. However, along with Indonesia's economic growth, small-scale construction service providers owner has a chance to expanse their business. Based on their experience, small-scale construction service providers have limitations. They cannot take a priority, whereas the risky of the contract construction. This study aims to make a list order of the construction risk based on medium-scale construction service providers. With this study, we want to help share the medium-scale experience to small-scale construction service providers in terms of risk contracts in Indonesia to learn and anticipate it. We conduct risk identification by literature and make list order analyzing using Analytical Hierarchy Process (AHP). AHP method can provide a single and easy-to-understand of unstructured problems. This research indicates that mismatch between the volume of work in the Bill of Quantity and field conditions is the most risk in terms of contract construction. However, the lump sum contract also identified the risky contract based on medium-scale construction service providers.

At this time, social networking is becoming a very popular communication tool among Indonesians ranging from children to adults. One of them is Twitter, which has quite a lot of users. This social network is used by users to write their opinions on a matter. One of the topics discussed in the Twitter social network is the Trans-Jakarta bus. In this study, the opinions of Trans-Jakarta bus users listed on Twitter are only limited to positive and negative opinions. An application designed to predict positive or negative opinions using the Naïve Bayes algorithm. The Naïve Bayes algorithm was chosen because it only requires a small amount of training data to estimate averages and variable variations. The developed application can make it easier for decision-makers towards Trans-Jakarta to find out public opinion on Trans-Jakarta bus services. The resulting system accuracy is 73% because the amount of training data used is only 62.5% of the total data of 50 data. While the test data that has been used are only 30 data. The proportions of the training and testing data affect the level of accuracy, so if you want a higher level of accuracy you can reproduce the training data used.

The essential oil from Cymbopogon nardus is widely used in industry, especially medicine and perfume. The microwave assisted method has been successfully applied to a laboratory extraction scale, namely Microwave Hydrodistillation. Therefore, it is necessary to increase the distiller capacity to increase the amount of essential oil obtained. The purpose of this study was to increase the scale of the extraction space through hydrodistillation made from microwaves to produce citronella oil with high yield. It was extracted compared to three distillers 1, 2 and 3 L. The feed to solvent ratio marked as F/S was 0.05 - 0.15 g / and microwave power was 400 – 800 W and extraction time 20 – 60 min. The yield obtained slightly decreased with increasing distiller volume for power parameters and F/S ratio. The highest extraction results using the MHD method occurred at 0.5 cm of material size, 800 W of power and 0.05 g / ml of F/S ratio was 1.81%. GC-MS analysis of citronella oil obtained from the dry leaf extract of Cymbopogon nardus showed that the main bioactive composition of citronella oil was citronell, geraniol, and citronellol at 73.76%. Therefore, it makes sense to extract citronella oil from the dried leaves of Cymbopogon nardus by using a larger distiller size.

Roselle flower contains various active compounds including organic acid, hydroxycitric acid, hibiscus acid, anthocyanin, flavonoids and polysaccharides The anthocyanin compounds in rosella flowers are the most important pigment of vascular plants, harmless and that make it interesting is a soluble pigment in water media Anthocyanin extract is one of the most successful natural sensitizers for solar cells, because this organic dye produces a high yield of photons to current conversion and is easy to obtain and cheap. Anthocyanins can be potential as sensitizers, because they range in the light spectrum from red to blue. The purpose of this study was to obtain anthocyanin pigments at the optimum extraction conditions from roselle flowers. The optimization of the method was carried out by analyzing the effect of ultrasonic wave frequency, process temperature, extraction time, and mass ratio of roselle flowers to the volume of distilled water on the anthocyanin concentration. The qualitative and quantitative compositions of the anthocyanin extract of rosella flowers were analyzed by UV-Vis spectrophotometer. The results showed that the optimal operating conditions for the extraction process were known at a temperature of 40 °C, a frequency of 24 kHz, a time of 5 minutes, and a ratio of 1: 25.

Wind energy is one of the several types of renewable energy that exist today. however, wind energy has a high degree of uncertainty due to weather effects. Wind speed prediction is needed to determine the energy that wind turbines can produce at each unit. For optimizing wind speed schedulling, the accuracy of wind speed prediction is considered. Extreme learning machine (ELM) and neural network (NN) is implemented to predict hourly wind speed for 24 hour and power generation from wind turbines can produce. Wind speed probability data is taken from sidrap wind farms in indonesia. To determine the performance of wind predictions based on the error value between actual and predicted, mean absolute percentage error (MAPE) is applied.

Synthesis of a catalyst by a sol-gel method is commonly conducted using a template to form pores to increase the number of active sites. In this work, mesoporous silica-carbon composites were prepared by sol-gel method using polyethylene glycol (PEG) 6000 as the template. Sodium silicate, commercially known as water glass, a cheap material, was used as the silica source. Here, PEG 6000 served as both the carbon source and the template. The silica-PEG composite was then carbonized at 550°C for 1 h to obtain silica-carbon composite. The sulfonate group was grafted into the composite by sulfonation with sulfuric acid at 100°C for 5 h. The sulfonated silica-carbon catalyst had a surface area of approximately 1490.8 m²/g. The very high surface area was able to hold a large amount of sulfonate group resulting an ion capacity of approximately 2.09. The composite was successfully be used as heterogeneous catalyst for esterification of acetic acid with ethanol with a conversion of 90.27%, higher than that of commercially Flotrol F-007.

Fly ash (FA) is burning coal product which is used as supplementary cementitious materials (SCM) as the conjunction with cement. The use of FA is considered by its pozzolanic properties i.e. SiO₂, Al₂O₃ and CaO to hardened concrete. The potential of FA as SCM has been well-known over the globe but that significant utilization has to be studied based on its compound's characteristics and pozzolanic activity. For this case, the amount of FA is added 30% by mass of total cementitious material, concrete with fly ash (NFA) and another blended without FA as normal concrete (NC) made of ordinary Portland cement. This amount is indicated as dosage in moderate to high volume of FA classification. This replacement pairs with water to cement ratio (W/C) with the value of 0.47 and 0.30 e.g., NC1, NC2 and NFA1, NFA2, respectively. These W/C uses considering effect FA on water demand of concrete proportioned for equal slump. The results showed that NC2 and NFA2 in the age of 28-day inform higher compressive strength, 30% and 28%, respectively. Another indication from the comparison of NC2 and NFA2 were also in good agreement that the use of FA decrease the compressive strength around 3% to 6%.

In construction work uses various types of heavy equipment to make road construction and maintenance, one of which is Cold Milling Machine. The use of cold milling machine is influenced by the operator efficiency factor in its operation and will have an impact on the productivity of the machine. The purpose of this study was to determine the productivity ratio between old and new operators and the number of efficiency factors for cold milling machine operators. The variable reviewed is the result of excavation from the cold milling machine operated by the operator. The research method used is direct observation in the field then the data is processed using t-test analysis. The results of this study are there are differences in skills between operator A and operator B based on the results of the t value (2.846> 1.812) greater than t table. The result of the calculation of the efficiency factor of cold milling machine operators is that by using a comparison of theoretical and actual productivity, it gets a very good category with a value of 0.84 for old operators and for new operators obtains a value of 0.48 which is categorized as less.

Based on the technology acceptance model, factors that form the intention to use of technology product of performed by individual users are perceived ease of use and perceived usefulness. The purpose of this study is to examine the effect of these two variables along with the attitude toward using as a part of the theory of planned behavior as the intervening variable. This research is conducted under quantitative with partial least square (PLS) method. The results show that perceived ease of use has no effect on other variables while perceived usefulness has a significant effect 0.191 on attitude toward using and effect 0.490 intention to use. In addition, there is a significant effect influence perceived usefulness as 0.581to attitude toward using and effect as 0.338 intention to use.

This paper presents a method for risk management applicable in shipbuilding projects. We focused this study specifically to assess delay in project completion by analysing the production processes. The production processes were grouped into three major parts, namely the work of design, material procurement, and production processes. Risk data were collected from risk documentation of fast patrol boat constructions in PT. PAL Indonesia (the company). Bayesian network was used to assess the probability of project completion delay. Noisy-OR canonical model was used to define parameters needed for the Bayesian network model. Based on the current condition, the Bayesian network model predicted that there is a probability of delay of 0.67761739 that the project completion will be delayed. The Bayesian network model was also used to assess mitigation actions to reduce the probability of delay. Three mitigation action sets were provided based on the complexity of mitigation action: (1) less complex mitigation action, (2) more complex mitigation action, and (3) most complex mitigation action. The Bayesian network model predicting that the most complex mitigation action would provide the best result in mitigating the project completion delay.

This paper presents numerical investigations in studying large web openings. Based on the previous guidelines, the web openings in reinforced concrete beams are being investigated. The simple verification design procedure is followed by ACI-318. In general, web openings have to consider a certain position so that each chord sides imply a sufficient area to expand the ultimate compression in flexure and give the appropriate reinforcement. In this case, two openings are placed nearly to one-half from support on each side. The analysis follows the recommended procedure for elastic bending moments and shear forces while the deflections are evaluated both in the short and long-term periods. It is found that the beam with a large web opening meets the required standard in all aspects, but it is indicative of having a large moment.

In this study, electrospinning technology, iodine treatment, thermal stabilizing, and carbonization processing were applied to produce lignosulfonate-based carbon nanofibers. The porous structure of the produced lignosulfonate-based carbon nanofibers primarily contained mesopores and a relatively small amount of micropores. Moreover, the increasing amount of sodium lignosulfonate (SLS) as lignin source was also studied. The diameter of fibre was impacted by the additional of SLS that may cause by the alkali content of SLS itself. In electrospun nanofiber phase, the presence of SLS reduce the specific surface area, but contrary increase the specific surface area after the nanofibers were carbonized into carbon nanofiber. Lignosulfonate-based activated carbon fibres can be used as a highly efficient adsorption and filtration material, and further development of its applications would be valuable.

Inexperience geotechnical engineer has difficulty in specifying the best type of weight of the hammer. Here, this study aims to help inexperience geotechnical engineers to decide the optimum weight of the hammer on the pile driving machine. The Bayes method is applied to decide between drop hammer and diesel hammer pile driving machines. Furthermore, we interviewed the expert by several questions about the criteria of the best pile driving machine using a Likert scale. The result suggests that the best type of pile driving is Drop Hammer. The weight of the hammer required to carry out the piling process is 0.9 ton. Recommendations for allowable bearing use the Meyerhof 1976 method. This condition meets the workload that more 141.14 tons at a depth of 26 m when using a square pile dimension of 35 x 35 and 40 x 40 cm. The dimensions are 45 x 45 cm, the recommended depth of piles is 26 m. the allowable bearing carrying when compared with the dynamic capacity using the Hilley, ENR, and WIKA methods meet the requirement. This is given the result of the allowable load-carrying capacity of 170 tons that less than 280 tons until 390 tons at dynamic capacity.

The vortex gravity system consists of a tube basin, a canal (worksection) and a water tank. Water is pumped into the upper tanker and flowed into the canal by opening the valve which then hits the tube basin and creates a whirlpool. The water that hits the tube and enters the outlet hole goes down to the lower tank and is circulated back to the upper tank. The outlet hole in the tube has 4 sizes and the tube size has 3 sizes. This study is based on experimental tests to determine the flow performance of the outlet diameter of the tube against the formation of vortices in the vortex tube. From several existing studies, the type of outlet hole in this tube has not been thoroughly studied. From the analysis results, it can be seen the difference in the results of each outlet size in the tube basin. With this question, this study aims to determine the strength of the vortex of the parameters that must be looked for, namely Water Flow Discharge (m3 / s), velocity (m / s), and Total Head Water (m). The vortex gravity system on a laboratory scale, based on previous studies or studies varying the diameter of the vortex tube and tube outlet hole, this study examined the effect of differences on the diameter of the vortex tube and the outlet hole of the tube basin. From the calculation of the vortex strength at the outlet hole of 25 cm, the results of the vortex strength are 7.53 m2 / s; 22.60 m2 / s; 45.21 m2 / s; 52.75 m2 / s. After that, proceed with the calculation of the outlet hole of 30 cm, the results of the vortex strength are 12.24 m2 / s; 28.26 m2 / s; 45.21 m2 / s; 56.52 m2 / s. Furthermore, the calculation at the 35 cm outlet hole obtained the vortex strength of 14.13 m2 / s; 30.14 m2 / s; 42.39 m2 / s; 60.28 m2 / s. the occurrence of fluctuation in the vortex strength results due to the energy available in the extracted water flow after hitting the outlet hole in the vortex tube. The graph produced in this calculation shows that the highest vortex strength occurs in a tube with a diameter of 35 cm.

Bangkalan Regency, located at the west of Madura Island covering the area 1,260.14 Km², has developed tremendously in some recent years, particularly in the post-development of Suramadu Bridge. To anticipate detrimental effects on the environment due to Bangkalan Regency improvement, the researchers developed software for calculating total CO₂ emissions of vehicles that could be absorbed by Green Open Space (GOS) in this city. The software was developed through Hypertext Preprocessor (PHP) based on the results of empirical study upon emission load and total trees calculation required for absorbing emission residue of vehicles. The software yielded from this research was successfully developed as indicated by the appropriateness of results between manual calculation and software one.

Quality control is an essential factor in producing products that are following what consumers want. The high quality of the product significantly affects the efficiency of costs incurred during the production process. This study aims to determine the types of defects and their causing factors as well as actions taken to reduce the number of defects to increase the efficiency of production costs. The measurement results obtained the number of productions of 12499 pcs with the number of defects of 2712 pcs of 21.6% with a sigma level of 3.1100 DPMO. Identification of defects in welding is porosity defects of 724 pcs, undercut defect of 613 pcs, slag defect of 435 pcs, crack defect of 491 pcs, and spatter defect of 449 pcs. The actions taken are periodic maintenance and repair of welding machines and connectors, supervising the condition and cleanliness of the material, providing periodic directions to welding operators by explaining reasonable welding procedures and arranging a welding field development program for welding operators through a job training program. Improvements have been implemented and found a reduction of defects up to 15% and a reduction of 6.6%.

The development of installed capacity in power plants in 2018 was 41.696 MW or increased from the previous year in 2017 amounted to 39.652 MW (PLN Statistics, 2018). This has an impact on the reduced availability of fuel due to overexploitation. The highest energy sold per customer group in 2018 was the household customer group that was 41.7% higher than the industrial sector customer group by 32.8% (PLN Statistics, 2018). At present the use of electronic equipment for household needs is increasingly diverse. Many equipment that is often used in daily life is electronic equipment that is inductive load. Inductive load causes the value of the power factor to fall so that the power usage (Watt) becomes less than optimal. To overcome the problem caused by the large number of inductive loads a reactive power compensator is needed which is to use a capacitor. In this final project, a system designed to be able to measure and correct power factors automatically uses the Neural Network method and can monitor power online based on IoT. The results of testing the power factor improvement system were 97.8% successful in the trained electric load and 94.8% in the untrained electrical load.