Center for Scientific Publication
Not a member yet
4029 research outputs found
Sort by
ASSESSMENT OF NOMINAL SHEAR STRENGTH OF REINFORCED CONCRETE COLUMN
Get PDF: SNI 2847-2019 and ACI 318-19 have regulated the use of materials in the design for shear strength. This study presents an evaluation of nominal shear strength in Reinforced Concrete (RC) column from SNI 2847-2019 and ACI 318-19 by variants of the RC columns experimental database. RC column variants consist of normal strength and high strength RC column with a total of 162 specimens. Furthermore, the database also provides a variety of shear span to depth ratio and axial-load ratio. In this study, the calculation was carried out the mean and the coefficient of variation of measured to calculated strength ratio which is according to SNI, ACI, and other experimental models. Both SNI 2847-2019 and ACI 318-19 have 2 different (concrete nominal shear strength) equations. The calculation results show that the equation is more conservative in both SNI and ACI compared to other nominal shear strength equations. Overall, the combination of both normal strength and high strength RC columns, the calculation using ACI 318-19 with the first nominal shear strength equation can be said to be more conservative than any other calculations models. This study also shows that by using the ACI 318-19 model in the second equation which is used the size effect modification factor , the results do not have a significant effect because the value is close to 1
COVER
No full textCover of International Journal of Offshore and Coastal Engineering Vol 5, No 1 (2021
Studi Penentuan Nilai Ekivalensi Mobil Penumpang (EMP) Pada Sepeda Motor Untuk Ruas Jalan 4/2D di Sidoarjo
Get PDFDalam menentukan kapasitas terdapat beberapa parameter yang dijadikan acuan, yaitu seperti Ekivalen Mobil Penumpang (EMP), hambatan samping, geometrik jalan, dan ukuran kota. Berdasarkan hasil Analisa kinerja ruas jalan yang dihitung menggunakan MKJI 1997 dirasa belum mewakili karakteristik lalu lintas yang ada saat ini. Perbandingan kinerja ruas jalan pada saat menggunakan EMP MKJI dan EMP time headway memiliki hasil yang signifikan, yaitu EMP time headway cenderung lebih besar dari EMP MKJI. Hal ini disebabkan karena adanya perbedaan volume kendaraan, karakteristik lalu lintas, geometrik jalan pada ruas jalan saat ini. Perbandingan kinerja jalan terbesar berada pada jam puncak sore pada ruas Jl. Majapahit arah Sidoarjo – Porong yaitu mencapai selisih derajat kejenuhan sebesar 0,646. Pada Jl. Jenggolo perbandingan terbesar berada pada jam puncak sore arah Sidoarjo – Surabaya yaitu mencapai selisih 0,939. Pada Jl. Pahlawan perbandingan terbesar berada pada jam puncak sore arah Sidoarjo – Krian yaitu mencapai selisih 0,144
Design of Bacterial Foraging Interval Fuzzy Logic Controller on Hybrid Solar Tracker-Ocean Wave Energy Converter
Get PDFThe location of Indonesia which, is crossed by the equator, makes it rich in sunlight. Photovoltaic (PV) can convert solar energy into electrical energy. The Solar Tracker system can maximize the absorption of solar energy that enters the PV. The condition of the Indonesian archipelago also has the potential for ocean wave energy. The Hydrostatic transmission-based Wave Energy Converter system can convert ocean wave energy into electrical energy. This research combines two energies, namely solar energy and ocean waves. The importance of combining these two renewable energies is due to the non-continuous nature of solar energy, therefore combined with the ocean wave energy to maximize the energy produced. A type-2 fuzzy logic control system based on Bacterial Foraging Optimization (BFO) is applied to each converter, summing each converter that has been optimizing. Optimize error and delta error on the solar tracker system and fuzzy logic waveform-based sea-wave type-2 system. The fuzzy boundaries are then optimized using the BFO optimization method. Fuzzy type-2 based on BFO in solar tracking system can increase energy by 67.9% with the best performance at FOU ±0.1. BFO-based type-2 fuzzy control can stabilize the output of the ocean wave conversion system and produce average energy of 34.48 Wh. This research can increase the energy in the system after being optimized using BFO by 19.3%
Estimation of the Catastrophic Risk using Mixture Models
Get PDFIndonesia is one of the countries in the world that is susceptible to various types of natural disasters such as earthquakes, floods, etc. These events do not occur very often, however, they cause massive financial loss. This risk of loss is termed as a catastrophic risk where it not only affects the individual but also the government and at the same time posing a threat to insurance companies if they do not have sufficient resources to make a payment of claims. However, due to the complexity and uncertainty of natural hazards, measuring this risk is quite challenging. This paper proposes an estimation method of the catastrophic risk based on Value-at-Risk (VaR) of total loss from natural disasters in Indonesia. A key issue for estimating VaR is to fit an appropriate distribution. Extreme value distribution, such as Generalized Pareto Distribution (GPD) has been used to assess the tail behavior of extreme loss. However, this distribution does not give any information about the central behavior that may affect the estimation of the model parameter in GPD. Therefore, this paper utilized mixture models that combine the parametric form of loss distributions such as gamma, Weibull, and lognormal distribution with GPD. The result shows that VaR estimations are quite different under different mixture models and confidence levels. In addition, the lognormal-GPD model is selected as the best model that fits data best with the highest value of Log-likelihoo
Optimization of Gas Turbine Component Maintenance to Improve Reliability of Power Plant Industries
Get PDFhe thermal power plant unit in Java is PLTGU Z with 3 blocks consisting of 9 gas turbines, and 3 steam turbines with a total installed capacity of 1578.78 MW. One of the problems faced is a high component failure rate, decreased system reliability, and an impact on rising maintenance costs. The method to be implemented in order to maintain the achievement of power plant performance and reliability of generating units is to optimize equipment reliability. Periodic component replacement is one way to maintain the reliability of the unit, where current conditions do not yet exist as a standard that is specifically used as a basis for the component replacement activities. For this reason, optimization of component replacement is required by considering the value of reliability, equipment downtime, frequency of replacement time, and costs required. It is intended that the reliability of the equipment is achieved at the optimum cost. The first stage is to identify the reliability value based on the failure data using Weibull ++ 6 software, then adjusted to the system reliability target in accordance with company standards. The second stage performs calculations to determine the minimum time of downtime and minimum preventive maintenance costs in a period of time. The third stage is determining the optimization of equipment reliability and the consequence of the required cost increase according to the system reliability target. After optimizing the reliability of the system with a target value of R(G) = 0.7 the optimization results obtained with the longest preventive maintenance intervals on gas nozzle equipment every 8000 hours, and the shortest maintenance time intervals are found on the fuel gas system equipment that is 40 hours
Formulation Stategies for Vocational High School in Surabaya ( Case Study: SMKS “X”)
Get PDFThis research focuses on strategic planning conducted at one of the private vocational high schools in Surabaya. Vocational school is one of the services in the education sector that aims to prepare students to work in specific fields. At this time, the number of students enrolling has decreased, so the need for proper strategic planning for schools in increasing the number of students. The method used in this study is the formulation of internal and external factors using the IFE and EFE matrices as the input stage and followed by determining the weights for each factor using pair comparison. In the next stage, this study uses the SWOT matrix as a strategy matching stage. The results showed the value of the IFE matrix. Schools had a total rating of 2.5, while the scores on the EFE matrix, schools had a total rating of 2.878. Based on an analysis of internal and external factors using the SWOT matrix, several alternative strategies can be obtained including Development of New Departments; Establish relationships with junior high schools in the same institution; Development of Learning Processes; Increased School Promotion; Maximizing BOS Funds; Collaboration with DU / DI; School Resource Development; School Culture Development and School Program Improvement; Improved School Performance and Quality. For the design of the strategy map obtained from four perspectives, including: (a) Financial Perspectives: Regular Provision of Budgets, Income Levels, Utilization of BOS Funds and School Imagery; (b) Customer Perspective: Number of Students, Customer Satisfaction, and School Quality; (c) Internal Business Perspectives: Marketing Development, Innovation, Process, After Sales Service, and Relationship Enhancement with DU / DI; (d) Learning and Growth Perspectives: Teacher / Staff Satisfaction, School Financial Management Development, Information System Capability, Teacher / Staff Development, and School Culture Development
Monitoring of Antioxidant and Antidiabetic Activity of Fractions from Ethyl Acetate Extract in Garcinia latissima Miq. Stem Bark
Get PDFThe genus Garcinia (Fam. Cluciaciae) is known as a source of phenolic compounds which are reported to have biological activities: antioxidants, antidiabetic, and anticancer etc. In this study, the monitoring was carried out for the antioxidant and antidiabetic activity of a number of fractions from the ethyl acetate extract of stem bark G. latissima Miq. (endemic plants, the Maluku Islands, Indonesia). The extraction process uses the maceration method with ethyl acetate solvent produced 240 g extract from 2 kg from dry bark of G. latissima Miq. Furthermore, the ethyl acetate extract was carried out by fractionation by Vacuum Liquid Chromatography (VLC) over the silica gel column and eluted using a mixture of n-hexane and ethyl acetate, with increasing polarity, and were obtained nine fractions (A-I). The Ethyl acetate extract and the all fractions were tested for antioxidant activities using radical DPPH (2,2-diphenyl-1-picrylhydrazyl) and antidiabetic activity using baker’s yeast and rat intestinal acetone powder. The inhibititon value (IC50) of fraction H was 0.03 µg/mL and fraction I was 0.06 µg/mL. Antidiabetic inhibititon value (IC50) using yeast of fraction H was 102.33 µg/mL and fraction I was 29.51 µg/mL, on the other hand antidiabetic inhibititon value (IC50) using rat intestinal of fraction H was 43.65 µg/mL and fraction I was 75.86 µg/mL. Based on monitoring data, it shown that the polar fraction H and I has the best inhibition activity than the other positive fractions, so that the active compound in fraction H and I need to be produced
General Bank's Profitability Analysis on The Impact of Going Public Process
Get PDFVarious reasons underlying the company's owner to Go Public processes such as increasing the company's capital, diversifying shares, overcoming lending constraints. Whatever the underlying reasons, Go Public decisions always have an impact on the company's finances and operations. There is a possibility for companies to not be able to manage funds from the Go Public process, causing a surplus of equity and an impact on decreasing company performance. This research was conducted to determine the impact of Going Public on company performance in terms of profitability. This study uses a purposive sampling technique to produce 3 sample banks that conduct an IPO in the period 2009- 2012 with the BOOK Bank category 2. Post-Go Public company performance is analyzed in terms of profitability using the financial ratios of Net Profit Margin ( NPM) and Gross Profit Margin (GPM). Hypothesis testing in the form of a paired t test was conducted on Net Profit Margin (NPM) and Gross Profit Margin (GPM) for the period of 4 years before and after going Public. The results of this study are expected to find out whether the process of Going Public has an impact on company profitability. In addition, the company's ability to perform cost efficiency can be measured through the use of the ratio of Net Profit Margin (NPM) and Gross Profit Margin (GPM)
Prioritization of Urea Fertilizer 4Ps Marketing Mix: A Case Study
Get PDFMarketing strategy has its own important roles in increasing sales. By formulating the right marketing strategy, a company can increase its sales significantly. 4Ps marketing mix is a tool, consist of Product, Price, Promotion, and Place, that widely used to formulate marketing strategy. It will be beneficial for a company if they know which P is the most important, so they can formulate specific marketing strategies and allocate their resources effectively. This study aims to find the important weight of each P in the 4Ps marketing mix used in the retail sales of urea fertilizer by PT. X using the Analytic Hierarchy Process. AHP is a method used by many decision-makers to solve Multi-Criteria Decision Making (MCDM) problems. Because of its simplicity and flexibility, AHP is frequently used to solve other problems. The General Manager and Manager of Marketing of the company are asked to give their judgment on the pairwise comparisons between each P of the 4Ps marketing mix, considering their impacts on sales. The result shows that Place has the highest important weight. Price is more important than Product, and Promotion is the least important. The study suggested the company to broaden its network, by adding more kiosks