IPTEK Journal of Proceedings Series
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Implementation of Fuzzy AHP Method to Determine the Best Alternative of Electric Energy Source for RKEF PT Vale Indonesia
Full text linkPT. Vale Indonesia is planning to build a RKEF to produce an additional 10 kT of nickel in a year. The 70 MW RKEF power requirement will be met from excess power from 3 hydro power plant and an additional 20 MW from other power plants. The selection of additional power plants is complicated because the selection process involves multiple conflicting criteria that can be either qualitative or quantitative, therefore a MCDM approach is carried out to obtain the best alternative by ranking according to criteria with regards to their relative importance and calculating weight of each criterion. Furthermore, the selection of the best alternative power plants will use the analogy between AHP and the geometric mean Fuzzy AHP method to choose a power plant. This selection is managed using six criteria, namely the price of electricity or LCOE, funding sources for investment costs, the effect of greenhouse gases, availability of resources, effects to the operations to the processing plant and utilities, and the duration of the project. There are 4 alternatives compared, namely PLTD, PLTS, ORC and PLTA, and the results of the selection show that PLTA has the highest value and was chosen as the best alternative
Isolation and antidiabetic Activity of Prenylated Xanthones from Pericarp of Mangosteen (Garacinia Mangostana Linn.)
Full text linkThe material used in this research was dry powder of pericarp mangosteen (Garcinia mangostana Linn.). which is a family plant of Clusiaceae. This taxa is known as the main source of prenylated xanthones derived from phenolic compounds. The compounds separation process was carried out by maceration method, 8 kg of sample macerated using n-hexane solvent, 90 g of n-hexane extract were produced. The n-hexane extract was fractionated by vacuum liquid chromatography (VLC) using silica gel, eluted by increasing the polarity of the solvent, which is a mixture of n-hexane solvent: dichloromethane (10%, 20%, 30% and 50%), resulting in three combined fractions, namely the first fraction 13,92 g, the second fraction 18,27 g, and the third fraction 23,24 g. The refraction process was then carried out in the third fraction, producing two yellow crystals with melting points respectively, 155-156 °C and 172-173 °C. The structural elucidation method was carried out using UV-Vis, IR, HR-ESI-MS, and NMR spectroscopy techniques. Based on the analysis of spectrum data from two known compounds, 8-deoxygartanin (1) and β-mangostin (2) antidiabetic bioactivity test was carried out by the method of inhibiting the enzyme α-glucosidase in vitro. The test results obtained by compound (1) with an IC50 value of 38,5 μM and compound (2) with an IC50 value of 157,9 μM indicate that the two compounds are included in the inactive category. This is indicated by the IC50 value which is much higher when compared to the acarbose as a positive control with an IC50 value of 4.5 μM
Implementation of Risk Management for Coal Switching in Coal Fired Steam Power Plant
Full text linkSteam Power Plant is the backbone of electricity sector in Indonesia. Steam Power Plants supply 27.5 GW to the grid, in which 90% of them is coal fired. Today, several Coal Fired Steam Power Plants face a supply problem; consequently, they must procure lower quality of coal. One of them is XYZ Coal Fired Steam Power Plant. Even if there are four candidates of provider to supply coal for a minimum 10 years, it is necessary to make assessment about the effects of coal switching on equipment. The risk assessment focuses on effects of each coal sample on equipment in plant site, especially the equipment closely related to firing process, i.e., boiler, electrostatic precipitator (ESP), and Seawater Flue Gas Desulfurization (SWFGD). Risk Breakdown Structure (RBS) is employed to map problem and problem root in equipment. Risk analysis and evaluation use House of Risk (HOR), meanwhile Net Present Value (NPV) is used to evaluate financial traits. HOR analysis shows one environmental factor, i.e., emission, becomes the highest risk as each coal has high ash content; hence it is necessary to improve emission control. Three of four candidates show high NPV values suitable for the company to maximize profitability
Designing a Master Program to Cope with the New and Next Normal (VUCA World, Industry 4.0, and Covid 19): a case study
Full text linkIt is not surprisingly that the combination of VUCA World and fast development of Industry 4.0 will become the era of new normal for any organization including but not limited to industries. This new normal will become either Threats and or Opportunities for any organization. Whatever it is, organizations should prepare themselves to face this era of new normal, especially to cope with (the unpredictable) uncertainties, such as the pandemic of Covid 19 and maybe other to come, that impact to the existing operation and future opportunities. At the end the uncertainties directly or indirectly will impact to the sustainability of the business. Therefore, this paper presents a strategic initiative, in term collaboration, between academic and professional to design a master program that cope with this new normal. This paper elaborates the concept of developing skills, upskilling and or reskilling, required to be able to handle uncertainties and complexities in the era of new normal. The concept is simply combining strengths of professional and academic and internalized in a tailored master education program. The concept then operationalized in a multi discipline master program as a case study in a top-notch private industry in Indonesia
Visitors Needs Analysis in Mall XYZ with Text Mining Analysis
Full text linkMall is a shopping center consisting of the main tenants (anchors), retail, shops, services, and public facilities that are built, managed, and arranged by the manager with the aim of conducting interaction between visitors and sellers. In 2018 Surabaya City had 33 malls or 50.77% of the total number of malls in East Java, this shows that the mall population in Surabaya City is very high. Mall XYZ is one of the malls that stood in the city of Surabaya and has been operating for one year. This mall still has not shown a development that is not optimal because of the many complaints from tenants to building management related to the sale of products that do not reach the target, as a result tenants often violate the rules (house rules) that have been set by managers to break the cooperation contract between building management and tenants unilaterally . To find out the cause of these conditions, text mining methods are used to filter reviews from visitors filtered from the Mall XYZ Google page. of the existing reviews classification will be based on reviews that contain positive and negative sentiment. review with positive sentiment becomes an appreciation that must be maintained and improved while a review containing negative sentiment becomes a complaint that must be addressed by the building management as the mall manager
Optimization Telecommunications Infrastructure Projects for University Area
Full text linkIn 2018-2019, utilization of data-based telecommunication was increased 82%. Signal measurement in Universitas Airlangga Surabaya is still low coverage because the distance between telecommunication towers and buildings. Surabaya City Government regulates the control of telecommunication towers including tower height, land, aesthetic, and tower sharing. One approach to solve this problem involves the use of concept Outdoor Distributed Antenna System (ODAS) or known as Base Transceiver Station Hotel (BTSH) which is support Microcell Pole (MCP), fiber-optic cable transmission, with configuration A Multiple-Carrier Multiple-Technology (MCMT). The tower provider company needs Optimal Hotel BTS design with measurement methods like Signal Strength, Signal Quality, and Point of Interest (POI). Planning a project schedule and project cost is using Critical Path Method (CPM) and Analytical Hierarchy Process (AHP) for further consideration regarding some criteria like revenue, cost, and technical. This analysis found that the most optimal calculation based on criteria weight is alternative project-1, by build a BTS Hotel in campus C, an 8 MCP tower, MCP fiber-optic cable with length ± 2418 m, and connecting campus A, B, C with length ± 8818 m, then project duration in 137 days with cost estimation IDR 7.8 billion
The Distribution of Damage to District Roads in Karang Penag Sub-District in Sampang District Uses Pavement Condition Index (PCI) and Spatial Poisson Point Process (SPPP)
Full text linkKarang Penang sub-district is a new sub-district after the division of territory in the Sampang Regency. This sub-district consists of seven villages. Sampang Regency is an area that is categorized as underdeveloped regions in East Java Province. This is indicated by the economic conditions and the low quality of human resources, and inadequate infrastructure. The last indication needs to be carried out regularly to ensure its continued functioning in supporting economic movements in this area. Delay in the identification of damage that often occurs in this area has caused delays in the maintenance of the facility. To overcome the delay in preparing the repair schedule, it is necessary to make a faster and more accurate assessment of road conditions. This study aims to assess the condition of the road pavement by combining the two approaches, namely the Pavement Condition Index (PCI) method and the Spatial Poisson Point Process (SPPP). The results of the modeling are expected to be able to identify the distribution pattern of the locations of damage points of the highway, to identify what parameters have a significant role in the distribution of the points of damage to the highway, and to be able to identify the level or condition of district highway conditions in Karang Penang District. The results of this study are able to provide predictions of the pattern of road damage conditions with varying intensity and influential factors between highway locations. These results, in turn, can provide information on the pattern of corrective actions that are more appropriate according to the damage criteria at these locations
Determination Program Priority by Applying Variance Analysis Method in Controlling Electricity Main Supply Cost
Full text linkPT. ABC is a State-Owned company managing the electricity sector to meet the needs of the community in providing electricity in Indonesia. Electricity is a commodity that effects the lives of many people, so the basic electricity tariff (TDL) to the community is determined by the government. On the other hand, PT ABC's electricity main supply cost (BPP), are the responsibility of PT ABC itself. The achievement of PT ABC's profits is largely determined by how the BPP is managed and controlled. As of March, the BPP target of the PT ABC power plant managed by PT XYZ was not achieved with an increase in deviation of 27.47 Rp/kWh. The causes of and solutions to the increase in BPP could not be known immediately because PT XYZ did not yet have an analytical method that could explain the causes and their proportions to the increasing deviation comprehensively. Therefore, this study is conducted using the Variance Analysis method in the selection process. The result of this study is the development of BPP controlling method by identifying the BPP component deviations from the predetermined standard costs and suggesting better decision making in prioritizing the work program
A Model of Supplier Selection Under Vendor Managed Inventory Contract
Full text linkVMI is the main concept for gaining accurate information and information sharing from customers to suppliers to achieve low safety stock levels, efficient inventory cost, and a reduction of ordering cost. There are many suppliers who supply spare part products under the VMI contract. Therefore, the company needs to make a decision for selecting a qualified supplier in order to improve customer service level and customer satisfaction. In addition, the uncertainty and vagueness of the expert's opinion is the prominent characteristic of the problem. Therefore an extensively used multi-criteria decision-making tool AHP can be utilized as an approach for supplier selection problems. This paper reveals the application of AHP model determining the best supplier with respect to selected criteria for selecting the best supplier under the VMI contract among the alternatives. There are criteria in this study namely quality, price, delivery, service, supplier’s background, and Information technology which include thirty subcriteria covers in the VMI contract. This research might be identified the critical criteria for supplier selection under the VMI contract
Analysis about the Effects of Ease of Use Site, Information Quality, Purchasing Trust, and Price Impression Towards Using of Online Shopping Blibli on Community in Semarang
Full text linkThis research aims to analyze the influence of ease of use site, quality information, purchasing trust, and the impression of price against visitor’s shopping intention on Blibi. The sampling method used on this research is probability sampling with random sampling technique. Samples were collected from 258 respondents who are community in Semarang who have visited the site Blibi. Analysis method used here is multiple regression analysis which includes validity test, reliability test, classic assumption test, multiple linear regression test, t-test, f-test, determination test. The result showed that the ease of use of the site, quality informartion, purchasing trust, and the impression of price has positive influence towards the shopping intention