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28,451 Article Results

An Improved AP-Wishart Classifier for Polarimetric SAR Images by Incorporating a Textural Features

10.12928/telkomnika.v13i1.1318
Chen; China University of Mining and Technology Jun , Du; China University of Mining and Technology Pei-jun , Tan; China University of Mining and Technology Kun
An improved classifier is presented by imposing a textural feature to solve the problems of vague initial clustering results, low classification accuracy and unchangeable class number in the iterative classifier, based on H/Alpha decomposition and the complex Wishart distribution for polarimetric SAR (Synthetic Aperture Radar) images. First, wavelet decomposition is used to extract texture from polarimetric SAR images. Second, an AP (Affinity Propagation) algorithm is applied to create the initial clustering result. This result is then applied to the iterative classifier based on the complex Wishart distribution to obtain the final result. Two PALSAR (Phased Array type L-band Synthetic Aperture Radar) images from ALOS (Advanced Land Observing Satellite) are used for the experiments carried out on experimental plots in Binhai Prefecture, Yancheng City, Jiangsu Province. The results show that the improved classifier has some merits, including clear initial clustering results, flexible class number and high classification accuracy. The improved classifier has better overall performance than the original, and can be effectively applied to the classification of polarimetric SAR images.
Volume: 13
Issue: 1
Page: 146-154
Publish at: 2015-03-01

Unbalanced Active Distribution Analysis with Renewable Distributed Energy Resources

10.12928/telkomnika.v13i1.960
Syafii; Andalas University Syafii , K. M.; Universiti Teknologi Malaysia Nor
This paper presents unbalanced active distribution system analysis with renewable distributed Energy Resources (DER). The renewable DER models have been considered are photovoltaic (PV) and Wind Turbine generation (WTG). The three-phase distribution load flow on the basis of the symmetrical components have been used in the analysis. The unbalanced active distribution system has been analized using IEEE 13 node feeder and IEEE 8500 node feeder with renewable DER units. The variation of wind speed (m/s) for WTG, solar radiation (W/m²) and temperature (°C) for PV have been simulated. The simulation results show that the proposed DER model can be used to analysis renewable DER impacts in unbalanced distribution system. The integration of renewable DER units into an existing distribution network can improve the voltage profile and reduce total system losses. The simulation results show that DERs size and location are important factors to improve voltage profile and line loss reduction.
Volume: 13
Issue: 1
Page: 21-31
Publish at: 2015-03-01

Color Image Enhancement Based on Ant Colony Optimization Algorithm

10.12928/telkomnika.v13i1.1274
Haibo; Hunan International Economics University Gao , Wenjuan; Hunan International Economics University Zeng
In the collection, transmission, decoding process, the images are likely to produce noise. Noise makes the image color distorted and the articulation dropped, and also affects the image quality. Due to different causes, there are different types of noise, and the impulse noise is most common among them which exert great influence on the image quality. This paper, according to the characteristics of the color image, combines the ant colony algorithm and weighted vector median filter method to put forward an algorithm for the impulse noise removal and the color image enhancement. This method finds the optimal filter bank parameter by ant colony optimization (ACO) and processes image points polluted by the noise to achieve the purpose of image enhancement and protect the image details and edge information. Simulation experiment proves the correctness and validity of this method.
Volume: 13
Issue: 1
Page: 155-163
Publish at: 2015-03-01

Received Signal Strength Indicator Node Localization Algorithm Based on Constraint Particle Swarm Optimization

10.12928/telkomnika.v13i1.1263
Songhao; Nanyang Normal University Jia , Cai; Nanyang Normal University Yang
Because the RSSI value greatly changes, the direct use of RSSI value has more errors in the positioning process as the basis to calculate the position of anchor nodes. This paper proposes a RSSI node localization algorithm based on constraint particle swarm optimization (PSO-RSSI). In the algorithm, particle swarm optimization is used to select anchor nodes set which are near the unknown node. The algorithm takes an element in the set, and measure distance between it and the other elements in the set. Then, the maximum likelihood method is used to calculate the coordinates. According to the difference between the calculated coordinates and the actual coordinates of the anchor node, the obtain coordinate of unknown node is corrected. When all the elements in the set perform such operation, the statistical methods are used to determine the coordinates of the unknown node. The algorithm embodies all the reference points influence on positioning, corrects the error problem on a single reference node positioning in the past. The simulation results show that the effect of the PSO-RSSI algorithm is more excellent.
Volume: 13
Issue: 1
Page: 221-229
Publish at: 2015-03-01

Toward a Framework for Indonesian Medical Question Generator

10.12928/telkomnika.v13i1.648
Wiwin; Institute Teknologi Bandung Suwarningsih , Iping; Institute Teknologi Bandung Supriana , Ayu; Institute Teknologi Bandung Purwarianti
Question generating is the task of automatically generating questions from various inputs such as raw text, database, or semantic representation. In this paper, we attempt to describe a general framework that could help develop and characterize efforts to medical Indonesian generates questions medical text. We propose a new style of question generation that actively uses sentences within a document as a source of answer. We use manually written rules to perform a sequence of general purpose a syntactic transformation (e.g. identification of keywords or key phrase to NER based on PICO frame) to turn a declarative sentence into questions. The final result of this research is a pattern of question and answer pairs, where the test results show the pattern matching algorithm precision value of 0.101 and a recall of 0.712.
Volume: 13
Issue: 1
Page: 357-363
Publish at: 2015-03-01

Lightning Air Terminal Collection Volume Assessment: A New Technique and Device

10.12928/telkomnika.v13i1.1354
Zainuddin; Universitas Sriwijaya Nawawi , Hussein; Universiti Teknologi Malaysia Ahmad , Muhammad; Universiti Teknologi Malaysia Abu Bakar Sidik , Lim Pai; Universiti Teknologi Malaysia Hung , Aulia; Universiti Teknologi Malaysia Aulia , Hamizah; Universiti Teknologi Malaysia Shahroom , Muhammad Irfan; Universitas Sriwijaya Jambak
For buildings, structures and facilities a Lightning Protection System (LPS) is very important. There are some components that affect the effectiveness of LPS. One of the components is the lightning air terminal. With reference to the facilities requiring lightning protection the position, the apparent height, and the angle of protection of lightning air terminals determines the collection volume (CV) of the protected area. The CV of direct strike lightning air terminals can change because of the facility is affected by natural disasters such as seismic tremor and flood. If such natural disasters do happen, there are possibilities that the facilities will not be fully protected from direct lightning strikes. The building and structure could be misalignment after the seismic tremor and flood related to earth movement. So for the safety of equipment and personnel, lightning protection system efficacy assurance is necessary. Therefore, there should be a technique and device to monitor the variation of collection volume afforded by every lightning air terminal on buildings and structures after the occurrence of a natural disaster. This paper presents a new technique as well as a new device to monitor the collection volume variation. A part of the device was obtained from a recycled moveable television antenna. This approach is not only practical, portable and cost effective but also incorporating the idea of environmental protection and recycling of used plastic materials.
Volume: 13
Issue: 1
Page: 13-20
Publish at: 2015-03-01

Variable Step Size Perturb and Observe MPPT for PV Solar Applications

10.12928/telkomnika.v13i1.1180
Awang; Universiti Teknologi Malaysia Bin Jusoh , Omer Jamal Eldin; Universiti Teknologi Malaysia Ibrahim Mohammed , Tole; Universitas Ahmad Dahlan Sutikno
In order to deliver maximum output of photovoltaic (PV) cells, the usage of maximum power point tracking (MPPT) is essential. The speed and stability of the tracking technique are highly desired. Perturb and Observe (P&O) is one of the most common tracking techniques, but it suffers from the slow tracking speed at small duty cycle step and fluctuates when subjected with large duty step, which results in higher losses under dynamic weather to which the photovoltaic (PV) cells exposed. In this paper, variable step size Perturb and Observe is introduced throughout Matlab/Simulink simulation to overcome this problem to achieve higher efficiency, reliable tracking accuracy and higher speed under fast changing weather. In comparison with other variable P&O techniques, the proposed method features a dynamic step size for more tracking efficiency and accuracy. Double diode modelling is used in this technique for better photovoltaic (PV) cell’s characteristic prediction. In this study, the adapted technique had been tested to wide range of sun irradiance and operation temperatures.
Volume: 13
Issue: 1
Page: 1-12
Publish at: 2015-03-01

A Self-Adaptive Chaos Particle Swarm Optimization Algorithm

10.12928/telkomnika.v13i1.1267
Yalin; Jiangxi University of Science and Technology, Ganzhou Wu , Shuiping; Jiangxi University of Science and Technology, Ganzhou Zhang
As a new evolutionary algorithm, particle swarm optimization (PSO) achieves integrated evolution through the information between the individuals. All the particles have the ability to adjust their own speed and remember the optimal positions they have experienced. This algorithm has solved many practical engineering problems and achieved better optimization effect. However, PSO can easily get trapped in local extremum, making it fail to get the global optimal solution and reducing its convergence speed. To settle these deficiencies, this paper has proposed an adaptive chaos particle swarm optimization (ACPSO) based on the idea of chaos optimization after analyzing the basic principles of PSO. This algorithm can improve the population diversity and the ergodicity of particle search through the property of chaos; adjust the inertia weight according to the premature convergence of the population and the individual fitness; consider the global optimization and local optimization; effectively avoid premature convergence and improve algorithm efficiency. The experimental simulation has verified its effectiveness and superiority.
Volume: 13
Issue: 1
Page: 331-340
Publish at: 2015-03-01

Characteristics Analysis of Non-linear Torsional Vibration in Engine and Generator Shafting system

10.12928/telkomnika.v13i1.129
Wei; University of Science & Technology Beijing Zhang , Wenming; University of Science & Technology Beijing Zhang , Xuan; University of Science & Technology Beijing Zhao , Miaomiao; Beiqi Foton Motor Co. , Ltd Guo
To solve the non-linear torsional vibration problem of engine and generator shafting causing body structural vibration and noise in motorized wheel vehicle, where the engine and the generator connected directly. First of all, analysis the characteristics of the shafting system, besides the external shock excitation of engine and generator. Then, through lumped parameter model method, mathematical model of the non-linear torsional vibration was established, which could reflect the dynamic characteristics of the system. Analysis the effect of mechanical parameters and electromagnetic parameters on the shafting. And get the non-linear differential equations of the system torsional vibration, which expresses the relation between structural parameters, electromagnetic parameters and the system dynamic characteristics. And multiple scales method was used to solve the equations. Non-contact measurement method was used in the torsional vibration test. Finally, consistency of the results, indicate that the research method used is reliability and accuracy, and get the critical speed of the shafting torsional vibration.
Volume: 13
Issue: 1
Page: 41-54
Publish at: 2015-03-01

Lip Motion Pattern Recognition for Indonesian Syllable Pronunciation Utilizing Hidden Markov Model Method

10.12928/telkomnika.v13i1.1302
Balza; Department of Engineering Physics, Faculty of Engineering, Universitas Gadjah Mada Achmad , Faridah; Department of Engineering Physics, Faculty of Engineering, Universitas Gadjah Mada Faridah , Laras; Department of Engiineering Physics, Faculty of Engineering, Universitas Gadjah Mada Fadillah
A speech therapeutic tool had been developed to help Indonesian deaf kids learn how to pronounce words correctly. The applied technique utilized lip movement frames captured by a camera and inputted them in to a pattern recognition module which can differentiate between different vowel phonemes pronunciation in Indonesian language. In this paper, we used one dimensional Hidden Markov Model (HMM) method for pattern recognition module. The feature used for the training and test data were composed of six key-points of 20 sequential frames representing certain phonemes. Seventeen Indonesian phonemes were chosen from the words usually used by deaf kid special school teachers for speech therapy. The results showed that the recognition rates varied on different phonemes articulation, ie. 78% for bilabial/palatal phonemes and 63% for palatal only phonemes. The condition of the lips also had effect on the result, where female with red lips has 0.77 correlation coefficient, compare to 0.68 for pale lips and 0.38 for male with mustaches.
Volume: 13
Issue: 1
Page: 173-180
Publish at: 2015-03-01

Knowledge Work Process: Software Developer’s in Small Medium Enterprise

https://ijeecs.iaescore.com/index.php/IJEECS/article/view/4237
Mohd Zairol Yusoff , Massudi Mahmuddin , Mazida Ahmad
Managing knowledge work in the workplace is inherently important and accessible to the organizations for the long terms growth and performance. Software developer is a key successor for the organization success and knowledge work is viewed as the highest complexity of work characteristics. The intentions of software developers to improve the knowledge work process are remain unconsciousness.The paper will address the issue of knowledge work process and try to proposed a method how to improve knowledge work process based on distinct methods and approaches. A literature review was used in order to distinguish the methods and will used data collected 300 respondents from Small Medium Enterprise (SMEs) in Malaysia and also validate the methods by using structural equation modelling. Our results provide evidence on the importance of certain method to improve knowledge work on the software developers and business success, and have implications for both research and practice in the field of SMEs. DOI: http://dx.doi.org/10.11591/telkomnika.v13i3.7134 
Volume: 13
Issue: 3
Page: 555-560
Publish at: 2015-03-01

Raptor Code for Energy-Efficient Wireless Body Area Network Data Transmission

10.12928/telkomnika.v13i1.924
Lydia; Atma Jaya Catholic University Sari , Antonius; Atma Jaya Catholic University Aditya
Wireless Body Area Network (WBAN) is a device developed mainly for the purpose of monitoring the medical condition of a human. WBAN is worn on the surface or in the human body, and it contains a wireless communication device.  A WBAN device is required to be small-sized, with limited power and high data reliability. The data reliability can be obtained by using a carefully designed channel coding scheme so that the energy consumed can be maintained at a low level.  In this paper, data transmission in Rayleigh, Rician, and Nakagami-m fading channels using Raptor and BCH codes is simulated.  Simulation results show that Raptor-coded data transmission consumes lower energy compared to BCH-coded transmission for various fading channels if the transmission distance exceeds 10 meters.  Therefore, Raptor code is a good candidate for the channel coding scheme for WBAN.
Volume: 13
Issue: 1
Page: 277-283
Publish at: 2015-03-01

Topology Architecture and Routing Algorithms of Octagon-Connected Torus Interconnection Network

10.12928/telkomnika.v13i1.1262
Youyao; Xi’an University of Posts & Telecommunications Liu , Lidong; Xi’an University of Posts & Telecommunications Xing , Xin; Xi’an University of Posts & Telecommunications Zhou
Two important issues in the design of interconnection networks for massively parallel computers are scalability and small diameter. A new interconnection network topology, called octagon-connected torus (OCT), is proposed. The OCT network combines the small diameter of octagon topology and the scalability of torus topology. The OCT network has better properties, such as small diameter, regular, symmetry and the scalability. The nodes of the OCT network adopt the Johnson coding scheme which can make routing algorithms simple and efficient. Both unicasting and broadcasting routing algorithms are designed for the OCT network, and it is based on the Johnson coding scheme. A detailed analysis shows that the OCT network is a better interconnection network in the properties of topology and the performance of communication.
Volume: 13
Issue: 1
Page: 305-313
Publish at: 2015-03-01

Unscented Particle Filtering Algorithm for Optical-fiber Sensing Intrusion Localization Based on Particle Swarm Optimization

10.12928/telkomnika.v13i1.1272
Hua; South-Central University for Nationalities Zhang , Xiaoping; South-Central University for Nationalities Jiang , Chenghua; South-Central University for Nationalities Li
To improve the convergence and precision of intrusion localization in optical-fiber sensing perimeter protection applications, we present an algorithm based on an unscented particle filter (UPF). The algorithm employs particle swarm optimization (PSO) to mitigate the sample degeneracy and impoverishment problem of the particle filter. By comparing the present fitness value of particles with the optimum fitness value of the objective function, PSO moves particles with insignificant UPF weights towards the higher likelihood region and determines the optimal positions for particles with larger weights. The particles with larger weights results in a new sample set with a more balanced distribution between the priors and the likelihood. Simulations demonstrate that the algorithm speeds up convergence and improves the precision of intrusion localization.
Volume: 13
Issue: 1
Page: 349-356
Publish at: 2015-03-01

Analysis and Identification the Complexity of Data Heterogeneity on Learning Environment Using Ontology

10.12928/telkomnika.v13i1.1321
Arda; Universiti Teknologi Malaysia Yunianta , Mohd Shahizan; Universiti Teknologi Malaysia Othman , Norazah; Universiti Teknologi Malaysia Yusof , Lizawati; Universiti Teknologi Malaysia Mi Yusuf , Juwairiah; Universiti Teknologi Malaysia Juwairiah , Nurul Syazana; Universiti Teknologi Malaysia Selamat
Distributed and various systems on learning environment are the current issues to produce big data and heterogeneity data problem. Heterogeneity on learning environment is about numerous learning applications and various learning information to support a learning process in educational institutions. There are a lot of relationships are formed between elements on learning environment. The elements on learning environment consist of learning data, learning applications, data sources, learning concept, and data heterogeneity aspect on learning environment. These elements are interrelated and produce complex relationship between each other. A complex relationship problem between elements on learning environment makes a process of analysis and identification difficult to be done. Existing method to drawing this heterogeneity problem make confuse and misunderstanding readers. To solved this problem, researcher using ontology knowledge to describe and draw a semantic relationship that represent the complexity of data relationship on learning environment. The result of this analysis is to develop ontology knowledge to solve heterogeneity data problem specific in complexity relationship on learning environment. This result can give better understanding to the readers about complex relationship between elements on learning environment.
Volume: 13
Issue: 1
Page: 341-348
Publish at: 2015-03-01
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