IJITEE (International Journal of Information Technology and Electrical Engineering)
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The Breakdown Voltage Characteristics of Bamboo Insulation under Composite Layer Based
Get PDFToday, insulation system involves more than one insulation material, whether serial, parallel, or both. In insulation system, the simplest form is composite which consists of two layers of the same material. The benefit of using layered insulation is that the dielectric strength is higher than one layer with the same thickness. There are two methods to test bamboo isolator, i.e., tests of the breakdown voltage of bamboo wall and bamboo fiber. The tests used two methods of composite layers (acrylic and resin) and without composite layer (normal condition). The tests were intended to observe the breakdown voltage on each incidence in each test sample and discover the dielectric strength. The test result showed that the breakdown voltage of bamboo wall was bigger than bamboo fiber with or without composite layer. The highest dielectric strengths of acrylic layer in petung bamboo wall were 2.07 kV/mm and acrylic layer in bamboo fiber was 0.95 kV/mm in layered method. Meanwhile, in ampel bamboo wall it was 1.35 kV/mm and petung bamboo fiber it was 0.43 kV/mm in normal condition (without layer)
Role Analysis of Distributed Generation Towards Transmission Expansion Planning Using MILP
Get PDFElectricity demand increase as function of population and economic activity growth. To meet the demand growth, one kind of approaches to expand electrical system is to calculate the need of generating unit and the result will be used to determine the needs of transmission line. In this research, a model was developed with focused on transmission line expansion based on Mix Integer Linear Programming method. The objective function was to minimize overall investment cost for transmission and operating cost of all generating units. The developed model was implemented in 6-bus Garver’s test system. Distributed generation implementation impact is also studied in this study in term of network configuration and overall expansion cost. The results show that distributed generation implementation will differ the network configuration and reduce the overall system cost, with overall system cost with and without distributed generation implementation was 103.18 million respectively
Study of Undersampling Method: Instance Hardness Threshold with Various Estimators for Hate Speech Classification
Get PDFA text classification system is needed to address the problem of hate speech in social media. However, texts of hate speech are very hard to find in social media. This will make the distribution of training data to be unbalanced (imbalanced data). Classification with imbalanced data will make a poor performance. There are several methods to solve the problem of classification with imbalanced data. One of them is undersampling with Instance Hardness Threshold (IHT) method. IHT method balances the dataset by eliminating data that are frequently misclassified. To find those data, IHT requires an estimator, which is a classifier. This research aims to compare estimators of IHT method to solve imbalanced data problem in hate speech classification using TF-IDF weighting method. This research uses the class ratio of dataset after undersampling, time of the undersampling process, and Index of Balanced Accuracy (IBA) evaluation to determine the best IHT method. The results of this research show that IHT method using the Logistic Regression (IHT(LR)) has the fastest undersampling process (1.91 s), perfectly balance dataset with the class ratio is 1:1, and has the best of IBA evaluation in all estimation process. This result makes IHT(LR) be the best method to solve the imbalanced data problem in hate speech classification
Feature Extraction Comparison in Handwriting Recognition of Batak Toba Alphabet
Get PDFOffline handwriting recognition is one of the most prominent research topics due to its tremendous application and high variability as well. This paper covers the offline Batak Toba handwritten text recognition, from the noise removal, the process of feature extraction until the recognition by using several classifiers. Experiments show that elliptic fourier descriptor (EFD) is the most discriminative feature and Mahalanobis distance (MD) outperforms the two others classifier
Prediction of Peat Forest Fires Using Wavelet and Backpropagation
Get PDFOne of the causes of smog as well as climate damage, particularly in Palangka Raya, Center Kalimantan, are peat forest fires. There are a lot of losses inflicted by the smog including the increasing number of people who suffer respiratory infection (ARI) due to polluted air and any other related aspects. Peat fires are problematic to overcome because the locations of fires are difficult to be accessed. This paper focuses on building the system to predict the distribution of peat forest fire hotspots by utilizing satellite imagery. In designing the system for predicting the fire hotspots distribution, wavelet orthogonal was used as the initial processing of mapping the distribution of peat forest fire hotspots. Meanwhile, backpropagation method was used to identify the fire hotspot distribution patterns of peat forest fire in this system. From the result of the data tested which had been done for predicting the peat forest fire hotspots, the decomposition image obtained using Haar wavelet had the highest percentage of accuracy to recognize the fire hotspots, which is 90%. The recency of this system was its ability to predict the peat forest fire hotspots distribution which can be used as peat forest fires prevention, especially in Palangka Raya, Central Kalimantan
The Radio Frequency Source Position Finder Based on The Triangle-Centroid-Algorithm
Get PDFoai:jurnal.ugm.ac.id:article/25140Radio Direction Finder (RDF) had been used as a part of the system in order to determine the direction of the Radio Frequency (RF) source. This research had used three different RDF stations without any mobile human operator. The direction data were collected from the each RDF station, it would be calculated using the triangle-centroid-algorithm. Therefore, the RF source position had been automatically determined. This experiment result of the RF source imaginary was compared with the real RF source at about 3.2 meters for latitude, and 3.3 meters for longitude. The results of this method and experiment are very useful for scientist and engineers in application of RF engineering
Development of Dutatani Website Using Rapid Application Development
Get PDFRapid Application Development (RAD) is a methodology used to develop software. This method is able to reduce time to develop software. This becomes consideration in order to choose the Rapid Application Development as a methodology to develop Dutatani Website. Dutatani is a portal and a part of Integrated Agriculture Information System (IAIS). IAIS is an agriculture information system that has some subsystems that are connected and linked to each other. It also has an integrated database. In particular, Dutatani is able to manage user, manage content, and manage link in the IAIS. This website will be a link to other applications in the IAIS. This article especially discusses the development of the Dutatani Website using Rapid Application Development that is implemented by combining iterative development and system prototyping. There are some phases in the development using the RAD: planning, analysis, main design specific design, implementation and testing, and integrating prototype. This system was developed by a team which consists five members. The implementation of this prototyping technique was done by dividing five people into two groups in which each group had different responsibilities to different module/functions. This website had been developed within 150 days. Thus, in implementing the RAD, it is important for the team leader to monitor continuously. Monitoring is a useful technique to ensure the productivity and performance of each members in order to gain optimal development process
Design of a Low Cost High Efficiency Multiple Output Self Oscillating Flyback Converter
Get PDFThe use of some integrated circuits in an SMPS circuit are the main factor that increasing the cost. Self-oscillating feedback converter topology is a well-known circuit topology for low-cost application without using any single integrated circuit chip. In this paper, a Low Cost with high efficiency converter without any single integrated circuit component was analysed and designed. It has also multiple outputs of 3.3 V/1 A, 5 V/0.5 A, and 12 V/0.1 A so that it can be used as power supply for DVD player. Experiment results showed that it can deliver continuously output voltage as designed and a total output power of 7.3 W, with an efficiency for about 70%
The Solution for Optimal Power Flow (OPF) Method Using Differential Evolution Algorithm
Get PDFOptimal Power Flow (OPF) is one of techniques used to optimize the cost of power plant production while maintaining the limit of system reliability. In this paper, the application of differential evolution (DE) method is used to solve the OPF problem with variable control such as the power plant output, bus voltage tension, transformer tap, and injection capacitor. The effectiveness of the method was tested using IEEE 30 buses. The result shows that this method is better than generic algorithm (GA), particle swarm optimized (PSO), fuzzy GA, fuzzy PSO, and bat-algorithm. The simulation of the power plant systems of 500 kV Java-Bali with the proposed method can reduce the total cost of generation by 13.04% compared to the operating data PT. PLN (Persero)
Performance of the PV Subsystems in Smart Micro Grid Sumba
Get PDFSmart Micro Grid (SMG) Sumba is inaugurated in 2012. The SMG consists of sub-system PV of a-Si/μc-Si with capasity 500 kWp, smart generator of 2x135 kVA, VRB of 2x240 kWh, and sub-system control and data communication. The output of the SMG is connected to the grid at 20 kV. Sub-system PV is connected to the 5 unit’s inverter of PV-grid type with each power capacity of 100 kW.At the beginning of operation, sub-system PV is operated at maximum level (100%). Electrical power is about 400 kW-500 kW supplied to the grid in clear daytime continuously from 10:00-15:00. When it is cloudy, the electrical energy supplied to the grid varies according to fluctuations in the intensity of light on the surface of PV arrays. Base load during the daytime in Southwest Sumba Regency at the time is about 1.5 MW, meaning that the contribution of electric energy of PV array is almost 30%. The change of cloud abruptly causes the output of PV to drop significantly, which could lead to black out at the local grid because the generators of PLN are not able to cover the power loss immediately. These restrictions result in Sumba SMG can not be operated optimally. Local power company can not tolerate frequent black outs due to the fluctuating of power injection from PV array.Over time some of the components of VRB are damaged so that the VRB is not enabled. Then, the SMG is applied to the extent of PV-grid connections, with the restriction of the power output of PV array at a rate of 30%, or power supplies 150 kW continuously during the daytime. As the SMG has been operated for about four years, the performance of the PV array has degraded about 20%-30%. The changes evidenced in the form of an electric current-voltage curves of PV module are measured by Sun-Simulator.In this paper, it is also discussed general information about the SMG system built in Southwest Sumba Regency, and specifically reviewing the performance of the sub-systems PV since it was built until now