Articles
220 Documents
<![CDATA[Techno-economic Assessment of Coal to SNG Power Plant in Kalimantan ]]>
<![CDATA[Riezqa Andika]]>;
<![CDATA[Valentina Valentina]]>
<![CDATA[ Indonesian Journal of Science and Technology Vol 1, No 2 (2016): IJoST: VOLUME 1, ISSUE 2, September 2016 ]]>
Publisher : <![CDATA[Universitas Pendidikan Indonesia ]]>
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DOI: 10.17509/ijost.v1i2.3792
<![CDATA[As the most abundant and widely distributed fossil fuel, coal has become a key component of energy sources in worldwide. However, air pollutants from coal power plants contribute carbon dioxide emissions. Therefore, understanding how to taking care coal in industrial point of view is important. This paper focused on the feasibility study, including process design and simulation, of a coal to SNG power plant in Kalimantan in order to fulfill its electricity demand. In 2019, it is estimated that Kalimantan will need 2446 MW of electricity and it reaches 2518 MW in 2024. This study allows a thorough evaluation both in technology and commercial point of view. The data for the model is gathered through literature survey from government institution reports and academic papers. Aspen HYSYS is used for modelling the power plant consists of two blocks which are SNG production block and power block. The economic evaluation is vary depends on the pay-back period, capital and operational cost which are coal price, and electricity cost. The results of this study can be used as support tool for energy development plan as well as policy-making in Indonesia.]]>
<![CDATA[Prediction and Classification of Low Birth Weight Data Using Machine Learning Techniques ]]>
<![CDATA[Alfensi Faruk]]>;
<![CDATA[Endro Setyo Cahyono]]>
<![CDATA[ Indonesian Journal of Science and Technology Vol 3, No 1 (2018): IJoST: VOLUME 3, ISSUE 1, April 2018 ]]>
Publisher : <![CDATA[Universitas Pendidikan Indonesia ]]>
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DOI: 10.17509/ijost.v3i1.10799
<![CDATA[Machine learning (ML) is a subject that focuses on the data analysis using various statistical tools and learning processes in order to gain more knowledge from the data. The objective of this research was to apply one of the ML techniques on the low birth weight (LBW) data in Indonesia. This research conducts two ML tasks; including prediction and classification. The binary logistic regression model was firstly employed on the train and the test data. Then; the random approach was also applied to the data set. The results showed that the binary logistic regression had a good performance for prediction; but it was a poor approach for classification. On the other hand; random forest approach has a very good performance for both prediction and classification of the LBW data set]]>
<![CDATA[Influences of Size and Amount of Colloidal Template and Droplet Diameter on the Formation of Porous-structured Hyaluronic Acid Particles ]]>
<![CDATA[Asep Bayu Dani Nandiyanto]]>;
<![CDATA[Kikuo Okuyama]]>
<![CDATA[ Indonesian Journal of Science and Technology Vol 2, No 2 (2017): IJoST: VOLUME 2, ISSUE 2, September 2017 ]]>
Publisher : <![CDATA[Universitas Pendidikan Indonesia ]]>
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DOI: 10.17509/ijost.v2i2.8016
<![CDATA[Combination of spray drying and templating method has been reported as one of the best method to produce porous pharmaceutical particles. However, current development reports have shown successful formation of porous particles with improper information on what mechanism occurs during the synthesis process and what process parameters involve the creation of particles with controllable pore structures and morphologies. In this report, influences of spray-drying parameters (i.e., size and amount of colloidal template, and droplet diameter) on porous particle fabrication were investigated. Hyaluronic acid (as a model of pharmaceutical drug host component) and polystyrene spheres (as a model of template) were used. The experimental results showed that the spray-drying parameters strongly influenced the external morphology (i.e., spherical and doughnut-shaped), particle outer diameter (from 300 to 2000 nm), and porous configuration (i.e., number of hole cavities and pore sizes (from 100 to 300 nm)) of particles. To qualitatively explain our synthesis strategies to get porous structure, the proposal of the particle formation mechanism was added.]]>
<![CDATA[Determination of Economic Order Quantity in a fuzzy EOQ Model using of GMIR Deffuzification ]]>
<![CDATA[Hamidreza Salmani Mojaveri]]>;
<![CDATA[Vahid Moghimi]]>
<![CDATA[ Indonesian Journal of Science and Technology Vol 2, No 1 (2017): IJoST: VOLUME 2, ISSUE 1, April 2017 ]]>
Publisher : <![CDATA[Universitas Pendidikan Indonesia ]]>
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DOI: 10.17509/ijost.v2i1.5990
<![CDATA[Inappropriate inventory control policies and its incorrect implementation can cause improper operation and uncompetitive advantage of organization logistic operation in the market. Therefore, analysis inventory control policies are important to be understood, including carrying cost, ordering cost, warehouse renting cost, and buying cost. In this research, Economic Order Quantity (EOQ) problem in fuzzy condition is reviewed in two different situations. The first model concerned to costs (carrying cost, ordering cost, warehouse renting cost and buying cost), which is considered as triangular fuzzy numbers. The second model was in addition to inventory the cost system, in which annual demand is also reviewed as fuzzy numbers. In each model, graded mean integration representation (GMIR) deffuzification was used for parameters deffuzification. Then, the final objective from this analysis was to obtain economic quantity formula through derivation.]]>
<![CDATA[High Temperature Oxidation Behavior of T91 Steel in Dry and Humid Condition ]]>
<![CDATA[Yonghao Leong]]>;
<![CDATA[Farah Alia]]>;
<![CDATA[Tedi Kurniawan]]>
<![CDATA[ Indonesian Journal of Science and Technology Vol 1, No 2 (2016): IJoST: VOLUME 1, ISSUE 2, September 2016 ]]>
Publisher : <![CDATA[Universitas Pendidikan Indonesia ]]>
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DOI: 10.17509/ijost.v1i2.3806
<![CDATA[High temperature oxidation behavior of T91 ferritic/martensitic steel was examined over the temperature range of 500 to 700°C in dry and humid environments. The weight gain result revealed that oxidation occurs at all range of temperatures and its rate is accelerated by increasing the temperature. The weight gain of the oxidized steel at 700°C in steam condition was six times bigger than the dry oxidation.. SEM/EDX of the cross-sectional image showed that under dry condition, a protective and steady growth of the chromium oxide (Cr2O3) layer was formed on the steel with the thickness of 2.39±0.34 µm. Meanwhile for the humid environment, it is found that the iron oxide layer, which consists of the hematite (Fe2O3) and magnetite (Fe3O4) was formed as the outer scale, and spinnel as inner scale. This result indicated that the oxidation behavior of T91 steel was affected by its oxidation environment. The existence of water vapor in steam condition may prevent the formation of chromium oxide as protective layer.]]>
<![CDATA[Influence of Clay on Time Domain Induced Polarization ]]>
<![CDATA[Yatini Yatini]]>
<![CDATA[ Indonesian Journal of Science and Technology Vol 3, No 1 (2018): IJoST: VOLUME 3, ISSUE 1, April 2018 ]]>
Publisher : <![CDATA[Universitas Pendidikan Indonesia ]]>
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DOI: 10.17509/ijost.v3i1.10794
<![CDATA[The main problem in mineral exploration is how to determine the existence of deposits at subsurface based on resistivity and chargeability parameters. Clay almost exists in rocks. Here, this study was to understand the influence of clay on time domain induced polarization. To clarify the clay parameters, field physical modeling was conducted. The results showed physical modeling data of 20-cm diameter spherical target with a total content of 28.3% of iron did not show any significant response. The high content of clays on the medium used in field physical modeling seems to be the main reason for the change in sample. In the case of the subsurface spherical model that is near to the soil medium, the presence of clay leads to the medium resistivity value to be identical to the target value. As a consequence, the resistivity response can not be identified clearly. The chargeability between the medium and the target remains small but the chargeability response remains constant.]]>
<![CDATA[Failure Investigation of Plastic Shredding Machine’s Flange Coupling Based on Mechanical Analysis ]]>
<![CDATA[Ignatius Pulung Nurprasetio]]>;
<![CDATA[Bentang Arief Budiman]]>;
<![CDATA[Farid Triawan]]>
<![CDATA[ Indonesian Journal of Science and Technology Vol 2, No 2 (2017): IJoST: VOLUME 2, ISSUE 2, September 2017 ]]>
Publisher : <![CDATA[Universitas Pendidikan Indonesia ]]>
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DOI: 10.17509/ijost.v2i2.7988
<![CDATA[This paper presented the investigation of failure mechanism of plastic shredding machine’s flange coupling which is made of cast steel. The machine unexpectedly stalled a few minutes after High-Density Polyethylene (HDPE) plastic bottles were fed into the machine. It was discovered afterward that the flange broke with the large crack surface. Finite element analysis (FEA) was performed to find the position and value of the critical stresses in the flange during operating condition. Subsequently, hardness test was conducted on the flange body to determine the Brinell hardness which was then converted into the approximate ultimate tensile strength (σu). As a result, a maximum Von Mises stress of 287 MPa was confirmed from the FEA to be concentrated in the flange’s keyway. Although this was found to be lower than the approximate σu obtained from hardness testing i.e. 449 MPa, the critical stress indicated an unstable condition which may induce a crack initiation any time when vibration or dynamic load occurs. Based on these analyses, it was concluded that the failure had been initiated by dynamic rather than static loading generated during machine stall condition. The dynamic load caused crack initiation at a stress concentration point of the keyway. The crack then propagated rapidly, breaking the flange body.]]>
<![CDATA[Monitoring System with Two Central Facilities Protocol ]]>
<![CDATA[Caesar Firdaus]]>;
<![CDATA[Wahyudin Wahyudin]]>;
<![CDATA[Eddy Prasetyo Nugroho]]>
<![CDATA[ Indonesian Journal of Science and Technology Vol 2, No 1 (2017): IJoST: VOLUME 2, ISSUE 1, April 2017 ]]>
Publisher : <![CDATA[Universitas Pendidikan Indonesia ]]>
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DOI: 10.17509/ijost.v2i1.5986
<![CDATA[The security of data and information on government’s information system required proper way of defending against threat. Security aspect can be achieved by using cryptography algorithm, applying information hiding concept, and implementing security protocol. In this research, two central facilities protocol was implemented on Research and Development Center of Mineral and Coal Technology’s Cooperation Contract Monitoring System by utilizing AES and whitespace manipulation algorithm. Adjustment on the protocol by creating several rule of validation ID’s generation and checking processes could fulfill two of four cryptography objectives, consist of authentication and non-repudiation. The solid collaboration between central legitimization agency (CLA), central tabulating facility (CTF), and client is the main idea in two central facilities protocol. The utilization of AES algorithm could defend the data on transmission from man in the middle attack scenario. On the other hand, whitespace manipulation algorithm provided data integrity aspect of the document that is uploaded to the system itself. Both of the algorithm fulfill confidentiality, data integrity, and authentication.]]>
<![CDATA[Optimization of Design and Planing VHS Building Using Chronolux ]]>
<![CDATA[Beta Paramita]]>;
<![CDATA[Ismahnida Kamilia]]>;
<![CDATA[Muhammad Iqbal Nurhidayat]]>;
<![CDATA[Resty Ocktaviyane]]>
<![CDATA[ Indonesian Journal of Science and Technology Vol 1, No 2 (2016): IJoST: VOLUME 1, ISSUE 2, September 2016 ]]>
Publisher : <![CDATA[Universitas Pendidikan Indonesia ]]>
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DOI: 10.17509/ijost.v1i2.3793
<![CDATA[Gedebage integrated vocational high school (SMK) is a school which accommodates the concept of technopolis. The school has four programs: building engineering, family welfare education (PKK/food service), mechanical engineering, and tourism - which produce skilled and ready-to-work graduates. This article aims to recommend the sun exposure toward the building of the school, which is related to site planning and design strategies based on the duration of solar radiation on vegetation, and building facades as well as the distance between buildings through the use of Chronolux plug-in on Sketch-up Software. From the measurement, it is found that vegetation can reduce sky view factors (SVF) from 76.4 to 38.87%. For the building façade, it is able to reduce sun exposure from 4 hours 51 minutes to 3 hours 19 minutes with SVF from 47.26 to 38.11%. Meanwhile, the building distance of 9 m receives sun exposure from 9:00 am to 3.42 pm.]]>
<![CDATA[Conformity of Vertical Public Housing's Performance With Resilience Agenda in Bandung Metropolitan Area ]]>
<![CDATA[Allis Nurdini]]>;
<![CDATA[Nur Fitra Hadianto]]>
<![CDATA[ Indonesian Journal of Science and Technology Vol 3, No 1 (2018): IJoST: VOLUME 3, ISSUE 1, April 2018 ]]>
Publisher : <![CDATA[Universitas Pendidikan Indonesia ]]>
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DOI: 10.17509/ijost.v3i1.10806
<![CDATA[The ideas of resilient housing have been rapidly developed for better future quality improvement. On the other side, resilience is a critical framework, which is not only for housing in the future but also for those that have been built and already inhabited. Therefore, it is necessary to conduct a study that can identify the compatibility of existing housing performance with the framework of resilience. Five vertical housing in Bandung were selected as case studies. These five housing are vertical public-housing prototype from national government that have been used in many cities for low income people. Post occupancy evaluation was used to assess the performance. Benchmarking and occupant survey instruments were combined in this study. The performance measurement results were then compared with critical resilient framework for housing to support community livelihood, reduce the vulnerability of resident to environmental risk and stresses, enhance personal security, and empower communities. It is concluded that the resilience of existing vertical public housing is differentiated according to the corridor design type and the occupant behavior to adapt the design. These two factors are closely linked to the achievement of resilient housing framework and are key inputs for short-term improvements in the vertical public housing that have been built.]]>
