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28,719 Article Results

Power Loss Minimization in Radial Distribution Networks Using Reconfiguration and DGs

10.11591/ijeecs.v7.i3.pp583-592
Sarfaraz Nawaz , Ajay Kumar Bansal , Mahaveer Prasad Sharma
A novel approach is proposed in this paper to achieve the objective of real power loss minimization and voltage profile enhancement. Network reconfiguration and allocation of various DG units are used to meet the objective. Selective particle swarm Optimization (SPSO) and novel analytical techniques are used to solve the problem of network reconfiguration and allocation of DG units simultaneously.  A new constant, Power Voltage Sensitivity Constant (PVSC), has been proposed to solve the allocation problem. The formulated mathematical expression (PVSC) determines site and size of DG units.  The level of DG penetration is considered in a range of 0–50% of total system load. A novel index is also proposed which incorporates level of DG penetration and % reduction in real power losses. Standard 69 bus system is used to validate the results obtained by proposed hybrid approaches. To show the efficacy and strength of the proposed hybrid approach, it has been compared with various techniques
Volume: 7
Issue: 3
Page: 583-592
Publish at: 2017-09-01

Neural Network-Based Stabilizer for the Improvement of Power System Dynamic Performance

10.12928/telkomnika.v15i3.3875
Rudy; Tanjungpura University Gianto , Kho; Tanjungpura University Hie Khwee
This paper develops an adaptive control coordination scheme for power system stabilizers (PSSs) to improve the oscillation damping and dynamic performance of interconnected multimachine power system. The scheme was based on the use of a neural network which identifies online the optimal controller parameters. The inputs to the neural network include the active- and reactive- power of the synchronous generators which represent the power loading on the system, and elements of the reduced nodal impedance matrix for representing the power system configuration. The outputs of the neural network were the parameters of the PSSs which lead to optimal oscillation damping for the prevailing system configuration and operating condition. For a representative power system, the neural network has been trained and tested for a wide range of credible operating conditions and contingencies. Both eigenvalue calculations and time-domain simulations were used in the testing and verification of the performance of the neural network-based stabilizer.
Volume: 15
Issue: 3
Page: 984-994
Publish at: 2017-09-01

A Crop Pests Image Classification Algorithm Based on Deep Convolutional Neural Network

10.12928/telkomnika.v15i3.5382
RuJing; Chinese Academy of Sciences Wang , Jie; Chinese Academy of Sciences Zhang , Wei; Anhui Academy of Agricultural Sciences Dong , Jian; Chinese Academy of Sciences Yu , ChengJun; Chinese Academy of Sciences Xie , Rui; Chinese Academy of Sciences Li , TianJiao; Chinese Academy of Sciences Chen , HongBo; Chinese Academy of Sciences Chen
Conventional pests image classification methods may not be accurate due to the complex farmland background, sunlight and pest gestures. To raise the accuracy, the deep convolutional neural network (DCNN), a concept from Deep Learning, was used in this study to classify crop pests image. On the ground of our experiments, in which LeNet-5 and AlexNet were used to classify pests image, we have analyzed the effects of both convolution kernel and the number of layers on the network, and redesigned the structure of convolutional neural network for crop pests. Further more, 82 common pest types have been classified, with the accuracy reaching 91%. The comparison to conventional classification methods proves that our method is not only feasible but preeminent.
Volume: 15
Issue: 3
Page: 1239-1246
Publish at: 2017-09-01

Effect of Pump Dithering at Each Stage of Cascaded Fiber Optical Parametric Amplifier

10.12928/telkomnika.v15i3.7212
Fatin; Universiti Tun Hussein Onn Malaysia Nabilah Mohamad Salleh , Nor; Universiti Tun Hussein Onn Malaysia Shahida Mohd Shah , Nurulanati; Universiti Tun Hussein Onn Malaysia Othman , Rahmat; Universiti Tun Hussein Onn Malaysia Talib , Munirah; Universiti Tun Hussein Onn Malaysia Ab. Rahman
Cascaded fiber optical parametric amplifier (FOPA) can enhance gain and bandwidth. The gain and bandwidth can be further enhanced by dithering the FOPA pump. However, to our knowledge, the effects of a pump dithering at every stage of cascaded FOPA have not been discussed. The study of performance at every stage of cascaded FOPA is quite interesting and beneficial in designing the system. Here, we analyzed, using OptiSystem software, each stage of a cascaded FOPA, when there was a pump dithering and not. The results showed that the pump dithering enhanced the gain and broaden the bandwidth at every stage. The gain and bandwidth obtained with the pump dithering were 27 dB and 20 nm, respectively. On the other hand, when there was no pump dithering, the gain and bandwidth were 9 dB and 12 nm, respectively.
Volume: 15
Issue: 3
Page: 1440–1445
Publish at: 2017-09-01

Noise Analysis in VLC Optical Link based Discrette OP-AMP Trans-impedance Amplifier (TIA)

10.12928/telkomnika.v15i3.5737
Syifaul; Microelectronic Center Institut Teknologi Bandung (ITB) Fuada , Trio; Microelectronic Center, Institut Teknologi Bandung (ITB) Adiono , Angga Pratama; Microelectronic Center, Institut Teknologi Bandung (ITB) Putra , Yulian; Microelectronic Center, Institut Teknologi Bandung (ITB) Aska
To design Visible Light Communication (VLC) system, there are several requirements that needs to be met. One of the requirements is an active component selection (e.g. Op Amp). As an ideal communication system, VLC system has to be able to provides wide bandwidth access with minimum noise. The Transimpedance amplifiers (TIAs) is one of main components in optical system which is placed in the first stage of receiver system. It is used to convert the current output from photodiode to voltage. We have designed a 1 MHz fGBW TIA with low noise (in μVrms range). This paper aims to explain the design and implementation of TIA circuit with photovoltaic topology which cover empirical calculations and simulation of TIA’s bandwidth and its noise sources, i.e. resistor feedback noise, current noise, voltage noise and total noise based on RSS. The OP-AMP is chosen from Texas Instruments product, OPA 380, and photodiode is chosen from OSRAM, SFH213, then simulated by TINA-TI SPICE® software. The noise in TIA circuit is analyzed clearly. The developed kit is ready to be implemented in VLC system.
Volume: 15
Issue: 3
Page: 1012-1021
Publish at: 2017-09-01

Twitter’s Sentiment Analysis on Gsm Services using Multinomial Naïve Bayes

10.12928/telkomnika.v15i3.4284
Aisah Rini; Bogor Agricultural University Susanti , Taufik; Bogor Agricultural University Djatna , Wisnu Ananta; Bogor Agricultural University Kusuma
Telecommunication users are rapidly growing each year. As people keep demanding a better service level of Short Message Service (SMS), telephone or data use, service providers compete to attract their customer, while customer feedbacks in some platforms, for example Twitter, are their souce of information. Multinomial Naïve Bayes Tree, adapted from the method of Multinomial Naïve Bayes and Decision Tree, is one technique in data mining used to classify the raw data or feedback from customers.Multinomial Naïve Bayes method used specifically addressing frequency in the text of the sentence or document. Documents used in this study are comments of Twitter users on the GSM telecommunications provider in Indonesia.This research employed Multinomial Naïve Bayes Tree classification technique to categorize customers sentiment opinion towards telecommunication providers in Indonesia. Sentiment analysis only included the class of positive, negative and neutral. This research generated a Decision Tree roots in the feature "aktif" in which the probability of the feature "aktif" was from positive class in Multinomial Naive Bayes method. The evaluation showed that the highest accuracy of classification using Multinomial Naïve Bayes Tree (MNBTree) method was 16.26% using 145 features. Moreover, the Multinomial Naïve Bayes (MNB) yielded the highest accuracy of 73,15% by using all dataset of 1665 features. The expected benefits in this research are that the Indonesian telecommunications provider can evaluate the performance and services to reach customer satisfaction of various needs.
Volume: 15
Issue: 3
Page: 1354-1361
Publish at: 2017-09-01

Estimation of Optimum Number of Poles for Random Signal by Yule-Walker Method

10.12928/telkomnika.v15i3.6103
Ahmed Al; Uttara University Amin , Md. Shoriful; Uttara University Islam , K.M. Abdul; Uttara University Al Woadud , Md. Jahirul; Uttara University Islam , Md. Imrul; Uttara University Kayes
The Yule-Walker method is an effective method to estimate the system response or spectrum for random signal. Hence most of the noise and spurious signals are random in nature, so it is very convenient to estimate their spectrum by Yule-Walker method successfully. The Yule-Walker method is an autoregressive process to estimate the poles and errors also based on the number of poles for Wide Sense Stationary (WSS) process as well. Moreover the value of zero will be correspondingly calculated based on the poles in case of all poles model. The main concern of this paper is to analyze the Yule-Walker method and estimate the poles and zero along with the error based on the number of poles for a random signal. Moreover analyze the results to find out the optimum number of poles for least possible error.
Volume: 15
Issue: 3
Page: 1192-1198
Publish at: 2017-09-01

Binarization of Ancient Document Images based on Multipeak Histogram Assumption

10.12928/telkomnika.v15i3.5105
Fitri; Syiah Kuala University Arnia , Khairul; Syiah Kuala University Munadi
In document binarization, text is segmented from the background. This is an important step, since the binarization outcome determines the success rate of the optical character recognition (OCR). In ancient documents, that are commonly noisy, binarization becomes more difficult. The noise can reduce binarization performance, and thus the OCR rate. This paper proposes a new binarization approach based on an assumption that the histograms of noisy documents consist of multipeaks. The proposed method comprises three steps: histogram calculation, histogram smoothing, and the use of the histogram to track the first valley and determine the binarization threshold. In our simulations we used a set of Jawi ancient document images with natural noises. This set is composed of 24 document tiles containing two noise types: show-through and uneven background. To measure performance, we designed and implemented a point compilation scheme. On average, the proposed method performed better than the Otsu method, with the total point score obtained by the former being 7.5 and that of the latter 4.5. Our results show that as long as the histogram fulfills the multipeak assumption, the proposed method can perform satisfactorily. 
Volume: 15
Issue: 3
Page: 1317-1327
Publish at: 2017-09-01

Miniaturized Minkowski-Island Fractal Microstrip Antenna Fed by Proximity Coupling for Wireless Fidelity Application

10.12928/telkomnika.v15i3.6826
I Putu Elba; Universitas Trisakti Duta Nugraha , Indra; Universitas Trisakti Surjati , Syah; Universitas 17 Agustus 1945 Jakarta Alam
This paper proposed a new design of Minkowski Island microstrip antenna fed by proximity coupling with partial ground plane. The design was consisted of two layers of substrate, on the top substrate was the antenna patch and on the bottom substrate was the proximity feed line and the partial ground. At the first stage, the normal square patch antenna was mainly designed. Then, the Minkowski patch antenna was designed using 1st iteration technique and 2nd iteration technique. The Minkowski fractal shape slot was embedded in the center of the patch to form a Minkowski Island patch antenna. Using the Minkowski Island fractal technique, the dimension of the patch can be reduced up to 58.7%. The proximity feed line in this design was used to increase the impedance bandwidth, and from the measurement the impedance bandwidth of the proposed antenna was 240 MHz with return loss of -24.54 dB and VSWR of 1.126.
Volume: 15
Issue: 3
Page: 1119-1126
Publish at: 2017-09-01

Classification Of Category Selection Title Undergraduate Thesis Using K-Nearest Neighbor Method

10.11591/ijeecs.v7.i3.pp846-854
Ratih Kumalasari Niswatin , Ardi Sanjaya
This research makes the classification system of  category selection title undergraduate thesis titleuse k-nearest neighbor method. This research will be conducted on the students of Informatics Engineering Department Faculty of Engineering, Universitas Nusantara PGRI Kediri. The purpose of making this system is to employee department and students to more easily make a classification of category selection undergraduate thesis title based on the field of interest and field of expertise of each student. The method used to classify the selection of undergaduate thesis title categories is k-nearest neighbormethod using several criteria based on students' interests and expertise in a particular field or course. The result of this sitem is an information category of undergraduate thesis title of students who have been processed based on the field of interest and field of expertise of each student.
Volume: 7
Issue: 3
Page: 846-854
Publish at: 2017-09-01

Design LTE Microstrip Antenna Rectangular Patch with Beetle-Shaped Slot

10.12928/telkomnika.v15i3.5493
Yusnita; Universitas Riau Rahayu , Haziq; Universitas Riau Hazman , Razali; Universiti Teknologi Malaysia Ngah
In this paper, the microstrip antenna rectangular patch with beetle shaped slot is presented. The characterization results of the proposed antenna obtained by changing the dimensions of the ground plane. CST software is used to design and analyze this proposed antenna. The simulated results of proposed antenna show that the antenna works at the frequency of 2.1 GHz while the return loss of -32.18 dB with the bandwidth reaches 155.19 MHz and the gain of 3.895 dBi.
Volume: 15
Issue: 3
Page: 1083-1087
Publish at: 2017-09-01

Skipped Zonal based Binary DCT (SZBinDCT) for Image communication over Resource Constrained Visual Sensor Network

10.11591/ijeecs.v7.i3.pp893-898
G. Suseela , Asnath Victy Phamila Y
The contemporary advancements in CMOS technology and Multimedia systems enabled image communication over resource constrained Visual Sensor Network (VSN). However, the size of image data is huge. It is wise to send the compressed image over the bandwidth limited network. Compression algorithms also should be of energy efficient with low complexity and should offer acceptable image quality. In this work an image coder offering low bit rate less than 0.5bpp is aimed. In this paper, a low memory and energy efficient skipped zonal based Binary DCT is proposed that codes the transformed samples using Golomb Rice code. Simulation results offered low bitrate 0.39 bpp with PSNR of 27.34 dB for the standard gray scale test image of Lena size 512 x512 pixels.
Volume: 7
Issue: 3
Page: 893-898
Publish at: 2017-09-01

Microstrip to Parallel-Strip Nonlinear Transition Balun with Stubs and DGS for UWB Dipole Antenna

10.12928/telkomnika.v15i3.7216
S.; Universiti Tun Hussein Onn Malaysia A. Hamzah , S.; Universiti Tun Hussein Onn Malaysia Mohd Shah , H.; Universiti Tun Hussein Onn Malaysia Majid , K.; Universiti Tun Hussein Onn Malaysia N. Ramli , M.; Universiti Tun Hussein Onn Malaysia S. Zainal , L.; Universiti Tun Hussein Onn Malaysia Audah , S.; Universiti Tun Hussein Onn Malaysia Z. Sapuan , A.; Universiti Tun Hussein Onn Malaysia Ubin , M.; Universiti Teknologi Malaysia Johore Baharu Esa , N.; Universiti Teknologi Malaysia Johore Baharu N. Nik Abd Malik
Three tapered baluns with nonlinear transition are developed for harmonic suppression in dipole antenna. The first balun consists of an exponential profile with the size of a quarter–wavelength for both the height and width with a wideband characteristic. However, for some applications such as narrowband harmonic suppression antennas and wideband-to-narrowband reconfigurable antennas, the suppression of higher operating band is desired. By employing stubs-filter and a defected ground structure (DGS), two narrowband tapered baluns are produced. They are named as an exponential balun-stub and an exponential balun-DGS, respectively, that operate from 1 to 2 GHz. A simulated and measured results that based on the reflection coefficient is found to be better than -10 dB from 1 to 2 GHz. The employment of the stubs and DGS have enabled these baluns to have the capability to reject the unwanted higher frequency band from 2.0 to 10 GHz. Finally, the proposed baluns are employed as a feeding circuit for an ultra wideband (UWB) circular dipole antenna that produces a reasonable outcome.
Volume: 15
Issue: 3
Page: 1470-1476
Publish at: 2017-09-01

An Efficient Patient Inflow Prediction Model For hospital Resource Management

10.11591/ijeecs.v7.i3.pp809-817
Kottalanka Srikanth , D. Arivazhagan
There has been increasing demand in improving service provisioning in hospital resources management. Hospital industries work with strict budget constraint at the same time assures quality care. To achieve quality care with budget constraint an efficient prediction model is required. Recently there has been various time series based prediction model has been proposed to manage hospital resources such ambulance monitoring, emergency care and so on.  These models are not efficient as they do not consider the nature of scenario such climate condition etc. To address this artificial intelligence is adopted. The issues with existing prediction are that the training suffers from local optima error.  This induces overhead and affects the accuracy in prediction. To overcome the local minima error, this work presents a patient inflow prediction model by adopting resilient backpropagation neural network. Experiment are conducted to evaluate the performance of proposed model inter of RMSE and MAPE. The outcome shows the proposed model reduces RMSE and MAPE over existing back propagation based artificial neural network. The overall outcomes show the proposed prediction model improves the accuracy of prediction which aid in improving the quality of health care management.
Volume: 7
Issue: 3
Page: 809-817
Publish at: 2017-09-01

Risky Sexual Behavior and Associated Factors Among High School Students in Gondar City, Northwest Ethiopia

10.11591/ijphs.v6i3.9293
Abebaw Wasie Kasahun , Mezgebu Yitayal , Tadele Girum , Bekri Mohammed
According to World Health Organization (WHO), youth are young people within 15-24 years old. Studies reported that more than half of all new HIV infections occur among people between the ages of 15 and 24 years. Institution based quantitative cross-sectional study was conducted among high school students in Gondar city. Multistage sampling technique was employed to recruit study participants. Data were collected using pretested structured self-administered questionnaire. Data were entered in Epi Info version 7 and analyzed using SPSS version 21. Descriptive statistics were computed to describe important variables in relation to the outcome variable, Binary and multivariable logistic regressions were used to identify independent predictors of the outcome variable. The overall prevalence of risky sexual behavior was 12.8%. Two out of five sexually active respondents ever had unprotected sexual intercourse.  Ever used alcohol ((AOR, 3.53 95% CI (1.73-7.19)), had no parental monitor (AOR, 12.21 95% CI (6.55-22.78), ever watched pornographic film (AOR, 2.24 95% CI (1.15-4.35), had no parental discussion on sexual and reproductive health issues (AOR, 2.57 95% CI (1.36-4.85) and peer pressure (AOR,2.50, 95%CI (1.20-5.21), were factors which significantly increases the odds of risky sexual behavior among youth. Risky sexual behavior among high school students in Gondar city administration was very high and worrisome; so that collaborated effort is needed from parents, schools, health facilities and health policy makers to bring healthy sexual behavior among school youth.
Volume: 6
Issue: 3
Page: 257-265
Publish at: 2017-09-01
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