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28,188 Article Results

A Fast Localization of Multiple Harmonic Sources for Rectifier Loads by Utilizing Periodogram

10.12928/telkomnika.v15i1.3120
M. Hatta; Universiti Teknikal Malaysia Melaka Jopri , A. Rahim; Universiti Teknikal Malaysia Melaka Abdullah , Mustafa; Universiti Teknikal Malaysia Melaka Manap , M. Rahimi; Universiti Teknikal Malaysia Melaka Yusoff , Tole; Universitas Ahmad Dahlan Sutikno
This paper introduces a fast method to localize the multiple harmonic sources (MHS) for rectifier based loads in power distribution system by utilizing periodogram technique with a single-point measurement approach at the point of common coupling (PCC). The periodogram is a fast and accurate technique for analyzing and distinguishing MHS location in power system. Matlab simulation is carried out several unique cases on IEEE test feeder cases due to validate the proposed method. The identification of MHS location is based on the significant relationship of spectral impedance which are fundamental impedance (Z1) and harmonic impedance (Zh) that's extracted from an impedance power spectrum. It is verified that the proposed method is fast, accurate, and cost efficient in localizing MHS. In addition, this method also contributes 100% correct identification of MHS location.
Volume: 15
Issue: 1
Page: 71-78
Publish at: 2017-03-01

Investigation Study of Three-Level Cascaded H-bridge Multilevel Inverter

10.12928/telkomnika.v15i1.4749
Mohd Ruddin; Universiti Teknikal Malaysia Melaka Ab Ghani , Nabil; Universiti Teknikal Malaysia Melaka Farah , Jurifa; Universiti Teknikal Malaysia Melaka Lazi , M.R.; Universiti Teknikal Malaysia Melaka Tamjis , Md Nazri; Universiti Teknikal Malaysia Melaka Othman , Nur Huda; Universiti Teknikal Malaysia Melaka Mohd Amin , Syariffah; Universiti Teknikal Malaysia Melaka Othman , Zanariah; Universiti Teknikal Malaysia Melaka Jano , Tole; Universitas Ahmad Dahlan Sutikno
This paper analyzed three-level Cascaded H-bridge Multilevel Inverter (CHMLI) utilizing two modulation techniques namely Sinusoidal Pulse Width Modulation (SPWM) and Space Vector Pulse Width Modulation (SVPWM). The performance and the output of CHMLI in terms of Total Harmonic Distotion (THD) % and circuits complexity were compared. The simulations models were constructed using MATLAB/SIMULINK. The results showed the CHMLI produced the lowest THD contents and utilized fewer components. Moreover, the SVPWM produced less THD than SPWM.
Volume: 15
Issue: 1
Page: 125-137
Publish at: 2017-03-01

Review on Psychological Crowd Model Based on LeBon’s Theory

10.12928/telkomnika.v15i2.6114
Vahid; Universiti Teknologi Malaysia Behtaji Siahkal Mahalleh , Hazlina; Universiti Teknologi Malaysia Selamat , Fargham; Universiti Teknologi Malaysia Sandhu
Irrational crowds tend to adapt herd mentality, having group behaviour and high suggestion through interaction. It is important to see how an irrational crowd can be controlled to prevent undesirable crowd attitude. This paper reviews existing models and the controllers to provide a comprehensive study for crowd control. It focuses on a comprehensive analysis of the control of psychological crowd, modelled using LeBon’s theory; which defines the crowd behaviour in terms of crowd attitude. The crowd attitude is defined in terms of suggestibility and prestige and the crowd interaction is defined in terms of the interaction of prestige and suggestibility, which is naturally unstable. A controller is required to achieve stability. In this paper several control approaches are described and the best control approach is highlighted. The results conclude, the best control approach is using multiple control agents, since the control effort is reduced and the stabilizing time is improved.
Volume: 15
Issue: 2
Page: 763-770
Publish at: 2017-03-01

Multiple Regression to Analyse Social Graph of Brand Awareness

10.12928/telkomnika.v15i1.3460
Yahya; Universitas Telkom Peranginangin , Andry; Universitas Telkom Alamsyah
Social Network Analysis (SNA) has become a common tool to conduct social and business research. In marketing SNA is used to measure word of mouth of a marketing campaign. For an example, a good marketing campaign should create intensive conversation between users in social media. In this paper we use SNA metrics to find out if we can predict brand awareness. We crawl conversation data from Twitter to form seven graph of seven brand in Indonesia. We use multiple regression method, an extension of linear regression, to analyse network properties to get insight on how network structure affect brand awareness of a product. Even though this research is still in early stage, but we manage to discover that a good network structure in knowledge dissemination case (such as word of mouth) eventually differ with the one in brand awareness.
Volume: 15
Issue: 1
Page: 336-340
Publish at: 2017-03-01

Recognition Technology for Four Arithmetic Operations

10.12928/telkomnika.v15i1.4063
Wang; School of Mechanical and Electronic Engineering, Wuhan University of Technology Meng , Bian; Air Force Logistics college Guangrong , Zheng; Wuhan University of Technology, Kai , He; Power Science Research Institute of State Grid Ningxia Power Co, Ninghui , Zhang; Air Force Service College Yanlei
Numeral recognition is an important research direction in field of pattern recognition, and it has broad application prospects. Aiming at four arithmetic operations of general printed formats, this article adopts a multiple hybrid recognition method and is applied to automatically calculating. This method mainly uses BP neural network and template matching method to distinguish the numerals and operators, in order to increase the operation speed and recognition accuracy. Sample images of four arithmetic operations are extracted from printed books, and they are used for testing the performance of proposed recognition method. The experiments show that the method provides correct recognition rate of 96% and correct calculation rate of 89%.
Volume: 15
Issue: 1
Page: 306-313
Publish at: 2017-03-01

Lighting Retrofit Scheme Economic Evaluation

10.11591/ijeecs.v5.i3.pp496-501
Mohd Firdaus Mohd Ab Halim , Umar Al-Amani Azlan , M. Haniff Harun , Khalil Azha M. Annuar , S. Halma Johari , A. Rahim Abdulla , M. Faisal Hushim
In this paper, two lighting retrofit scheme is simulated to evaluate the amount of saving that the commercial building owner would benefits. Simple payback period and net present value are the method used to qualify the retrofit scheme to be profitable or otherwise. The analysis include the effect of electricity price, energy saving percentage, technology price and efficacy future values towards the economic return. The retrofit scheme presented only covers for the building that already has existing lighting equipment and comply towards the standard set by the international technical society. All variables and assumption are based on latest report by the world governing bodies and regulation.
Volume: 5
Issue: 3
Page: 496-501
Publish at: 2017-03-01

A New Approach for Solving Inverse Scattering Problems with Overset Grid Generation Method

10.12928/telkomnika.v15i2.6127
Azarina; Politeknik Kuching Sarawak Azman , Shafrida; Universiti Malaysia Sarawak Sahrani , Kismet; Universiti Malaysia Sarawak Hong Ping , Dayang; Universiti Malaysia Sarawak Azra Awang Mat
This paper presents a new approach of Forward-Backward Time-Stepping (FBTS) utilizing Finite-Difference Time-Domain (FDTD) method with Overset Grid Generation (OGG) method to solve the inverse scattering problems for electromagnetic (EM) waves. The proposed FDTD method is combined with OGG method to reduce the geometrically complex problem to a simple set of grids. The grids can be modified easily without the need to regenerate the grid system, thus, it provide an efficient approach to integrate with the FBTS technique. Here, the characteristics of the EM waves are analyzed. For the research mentioned in this paper, the ‘measured’ signals are syntactic data generated by FDTD simulations. While the ‘simulated’ signals are the calculated data. The accuracy of the proposed approach is validated. Good agreements are obtained between simulation data and measured data. The proposed approach has the potential to provide useful quantitative information of the unknown object particularly for shape reconstruction, object detection and others.
Volume: 15
Issue: 2
Page: 820-828
Publish at: 2017-03-01

Comparison of Feature Extraction Mel Frequency Cepstral Coefficients and Linear Predictive Coding in Automatic Speech Recognition for Indonesian

10.12928/telkomnika.v15i1.3605
Sukmawati Nur; Diponegoro University Endah , Satriyo; Universitas Diponegoro Adhy , Sutikno; Universitas Diponegoro Sutikno
Speech recognition can be defined as the process of converting voice signals into the ranks of the word, by applying a specific algorithm that is implemented in a computer program. The research of speech recognition in Indonesia is relatively limited. This paper has studied methods of feature extraction which is the best among the Linear Predictive Coding (LPC) and Mel Frequency Cepstral Coefficients (MFCC) for speech recognition in Indonesian language. This is important because the method can produce a high accuracy for a particular language does not necessarily produce the same accuracy for other languages, considering every language has different characteristics. Thus this research hopefully can help further accelerate the use of automatic speech recognition for Indonesian language. There are two main processes in speech recognition, feature extraction and recognition. The method used for comparison feature extraction in this study is the LPC and MFCC, while the method of recognition using Hidden Markov Model (HMM). The test results showed that the LPC method is better than MFCC in Indonesian language speech recognition.
Volume: 15
Issue: 1
Page: 292-298
Publish at: 2017-03-01

Energy-efficient Compressive Data Gathering Utilizing Virtual Multi-input Multi-output

10.12928/telkomnika.v15i1.4507
Fang; Anhui University Jiang , Yanjun; Anhui University Hu
Data gathering is an attractive operation for obtaining information in wireless sensor networks (WSNs). But one of important challenges is to minimize energy consumption of networks. In this paper, an integration of distributed compressive sensing (CS) and virtual multi-input multi-output (vMIMO) in WSNs is proposed to significantly decrease the data gathering cost. The scheme first constructs a distributed data compression model based on low density parity check-like (LDPC-like) codes. Then a cluster-based dynamic virtual MIMO transmission protocol is proposed. The number of clusters, number of cooperative nodes and the constellation size are determined by a new established optimization model under the restrictions of compression model. Finally, simulation results show that the scheme can reduce the data gathering cost and prolong the sensor network’s lifetime in a reliable guarantee of sensory data recovery quality.
Volume: 15
Issue: 1
Page: 179-189
Publish at: 2017-03-01

Compact Power Divider Integrated with Coupler and Microstrip Cavity Filter for X-band Surveillance Radar System

10.12928/telkomnika.v15i1.5003
Yudi Yuliyus; Research Center for Electronics and Telecommunication - Indonesia Institute of Science Maulana , Yussi Perdana; Research Center for Electronics and Telecommunication - Indonesia Institute of Science Saputera , Arief Budi; Research Center for Electronics and Telecommunication - Indonesia Institute of Science Santiko , Arie; Research Center for Electronics and Telecommunication - Indonesia Institute of Science Setiawan
This paper present the compact power divider integrated with coupler and microstrip cavity filter for x-band surveillance radar system. These modules consist of several devices (splitter, filter and coupler) it is integrated in a single module aims to reduce the loss in the joint connectors. The bandpass filter is use microstrip cavity filter for operating on X-Band Frequency and deployed on RT/duroid 5880. The power divider and coupler is designed using quarter wavelength transformer. A theoretical analytical circuit model will be presented, from the theoretical model, a compact integrated module will be designed and simulated. The proposed compact integrated module is small in dimension and performs a compact size. The compact integrated devices design on X-Band frequency is simulated and the result is presented.
Volume: 15
Issue: 1
Page: 227-237
Publish at: 2017-03-01

Thermal Performance Analysis for Optimal Passive Cooling Heat Sink Design

10.12928/telkomnika.v15i2.6140
Nur Warissyahidah; Universiti Teknologi Malaysia Badrul Hisham , Fatimah; Universiti Teknologi Malaysia Sham Ismail , Muhammad; Universiti Teknologi Malaysia Azmi Ahmed Nawawi
Recent advances in semiconductor technology show the improvement of fabrication on electronics appliances in terms of performance, power density and even the size. This great achievement however led to some major problems on thermal and heat distribution of the electronic devices. This thermal problem could reduce the efficiency and reliability of the electronic devices. In order to minimize this thermal problem, an optimal cooling techniques need to be applied during the operation. There are various cooling techniques have been used and one of them is passive pin fin heat sink approach. This paper focuses on inline pin fin heat sink, which use copper material with different shapes of pin fin and a constant 5.5W heat sources. The simulation model has been formulated using COMSOL Multiphysics software to stimulate the pin fin design, study the thermal distribution and the maximum heat profile.
Volume: 15
Issue: 2
Page: 883-887
Publish at: 2017-03-01

Device Discovery Schemes for Energy-efficient Cluster Head Rotation in D2D

10.12928/telkomnika.v15i1.4676
Bhaskara; Telkom University Narottama , Arfianto; Telkom University Fahmi , Budi; Telkom University Syihabuddin , Desti; Telkom University Madya Saputri , Patricius Evander; Telkom University Christy , Obed; Telkom University Rhesa Ludwiniananda
 In this paper, novel device discovery approaches for the Cluster Head Rotation, which is a state-of-the-art method for the Device-to-Device communication, are proposed. The device discovery is the process to detect and to include new devices in the Device-to-Device communication. The proposed device discovery is aimed to attain energy efficiency for the communication devices. We propose two schemes for the device discovery: eNB-assisted and independent device discovery. Compared to previous work, the proposed device discovery is utilizing the cluster head rotation method, to achieve better energy efficiency. In this work, several simulations were performed and discussed for both schemes. In the first simulation, the device energy consumption is examined. After that, the number of devices that get rejected is studied. The device discovery processes in multi cluster head scenario, which is Cluster Head Rotation, are examined in this paper. The result of the simulation shows that eNB-assisted device discovery can provide better energy efficiency. Also, the number of rejected devices of the eNB-assisted device discovery is slightly lower than independent device discovery.
Volume: 15
Issue: 1
Page: 203-211
Publish at: 2017-03-01

Measurement Straight Leg Raise for Low Back Pain Based Grayscale Depth

10.12928/telkomnika.v15i1.4291
Tavipia; Gunadarma University Rumambi , Hustinawaty; Gunadarma University Hustinawaty , Sarifuddin; Gunadarma University Madenda , Eri Prasetyo; Gunadarma University Wibowo
Spinal disorders are the most frequent cause of pain and lower part of the spine, which is often called Low Back Pain.Straight Leg Raise Test  can provide important information to detect the cause of LBP. Straight Leg Raise test conducted by physican with a goniometer required accurately reading angle when your feet up. But this can be overcome with Kinect can detect motion and displays images and depth data. Methodological includes image acquisition method using RGB and Grayscale depth, skeleton tracking, feature extraction detection Straight Leg Raise . The proposed algorithm describes a method for estimating the data triangulation angle Straight Leg Raise by Kinect. Results measurement if   the positive Low Back Pain below 60 degrees there is a tendency to suffer from one of the causes of Low Back Pain. The results can be stored in the database as medical history and used to monitor the progress of therapy
Volume: 15
Issue: 1
Page: 471-477
Publish at: 2017-03-01

Parametric Analysis of Wearable Vialess EBG Structures and Its Application for Low Profile Antennas

10.12928/telkomnika.v15i2.6108
Adel; Universiti Tun Hussein Onn Malaysia (UTHM) Y.I. Ashyap , Zuhairiah; Universiti Tun Hussein Onn Malaysia (UTHM) Zainal Abidin , Samsul; Universiti Tun Hussein Onn Malaysia (UTHM) Haimi Dahlan , Huda; Universiti Tun Hussein Onn Malaysia (UTHM) A. Majid , Zuraidah; Universiti Tun Hussein Onn Malaysia (UTHM) Muhammad , Muhammad; Universiti Teknologi Malaysia (UTM) Ramlee Kamarudin
This paper is under in-depth investigation due to suspicion of possible plagiarism on a high similarity indexElectromagnetic Bandgap (EBG) structures are one class of metamaterial with attractive properties that unavailable in nature and widely used for improving the electromagnetic performance. Its In-phase reflection frequency band is indicated as operation frequency band, whose characteristic is closely related to the parameters of EBG structure, such as patch width (w), gap width (g), substrate height (h) and substrate permittivity (ε). The presence of via within EBG structure is associated with design and fabrication complexities, which led the researchers to study uniplanar EBG. These structures require no via and can easily be fabricated and integrated with RF and microwaves application.  Therefore, an investigation study on the effect of the parameters of the vialess EBG surface and some design guidelines have been obtained. An example of an antenna integrated with EBG is also studied. The result indicates that the EBG ground plane significantly improves the work efficiency of the antenna in a particular frequency band.
Volume: 15
Issue: 2
Page: 718-725
Publish at: 2017-03-01

Design and Development ofa Mirror Effect Control Prosthetic Hand with Force Sensing

10.12928/telkomnika.v15i2.6150
Maryam; UiTM Cawangan Pulau Pinang Hanan Yahya , Norhazimi; UiTM Cawangan Pulau Pinang Hamzah , Azizul; UiTM Cawangan Pulau Pinang Othman , Anis; UiTM Cawangan Pulau Pinang Diyana Rosli , Rohaiza; UiTM Cawangan Pulau Pinang Baharudin , Adi; UiTM Cawangan Pulau Pinang Izhar Che Ani
Some of the already available prosthetic hands in the market are operated in open loop, without any feedback and expensive. This system counters those by having the prosthetic hand printed using 3D printer and consist of a feedback sensor to make it a closed loop system. The system generally consists of two sections, mainly Finger Input and Prosthetic Output. The two sections communicate wirelessly for data transferring. The main purpose of the system is to control the prosthetic hand wirelessly using the Mirror Glove by performing a mirror effect that will translate movement from the glove onto the prosthetic hand. The Mirror Glove monitors the movements/bending of each fingers using force sensitive sensor. The prosthetic hand also has a sensor known as force sensitive resistor. The sensors will feedback the pressure on the prosthetic hand during object grasping, allowing the prosthetic hand to grasp delicate object without damaging it. Overall, the system will imitate the flex and relaxing of fingers inside the Mirror Glove and wirelessly control distant prosthetic hand to imitate the human hand.
Volume: 15
Issue: 2
Page: 949-956
Publish at: 2017-03-01
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