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27,404 Article Results

FPGA Implementation of Low-Area Square Root Calculator

10.12928/telkomnika.v13i4.1894
Aiman Zakwan; Universiti Teknikal Malaysia Melaka Jidin , Tole; Universitas Ahmad Dahlan Sutikno
Square root is one of the mathematical operations which are widely used in digital signal processing. Its implementation on hardware such as FPGA will provide several advantages compare to the performance offered in software. There are several algorithms which can be utilized for this calculation, but they are difficult to be implemented in FPGA. This paper presents a model of FPGA based square root calculator, which requires very low resources usage, thus occupying very low area of FPGA. The model is designed to suit the needs of medium-speed and low-speed applications which don’t need very high processing speed, while optimizing the number of resources utilized.The modified non-restoring algorithm is used in this design to compute the square root. The design is coded in RTL VHDL, and implemented in Altera DE2-board for hardware validation. The implementation produced very precise square root calculation, with low latency computation and low area consumption, for various input data width tested.
Volume: 13
Issue: 4
Page: 1145-1152
Publish at: 2015-12-01

Fundamental Review to Ozone Gas Sensing Using Optical Fibre Sensors

10.12928/telkomnika.v13i4.2047
Michael; Universiti Teknologi Malaysia David , Mohd Haniff; Universiti Teknologi Malaysia Ibrahim , Sevia; Universiti Teknologi Malaysia Mahdaliza Idrus , Tay Ching; Universiti Teknologi Malaysia En Marcus
The manuscript is a review of basic essentials to ozone gas sensing with optical methods. Optical methods are employed to monitor optical absorption, emission, reflectance and scattering of gas samples at specific wavelengths of light spectrum. In the light of their importance in numerous disciplines in analytical sciences, necessary integral information that serves both as a basis and reference material for intending researchers and others in the field is inevitable. This review provides insight into necessary essentials to gas sensing with optical fibre sensors. Ozone gas is chosen as a reference gas. Simulation results for ozone gas absorption cross section in the ultraviolet (UV) region of the spectrum using spectralcalc.com simulation have also been included.
Volume: 13
Issue: 4
Page: 1133-1144
Publish at: 2015-12-01

A Novel Approach to Optimize Cognitive Radio Network Utilization using Cascading Technique

10.12928/telkomnika.v13i4.2341
H Venkatesh; Nagarjuna College of Engineering & Technology Kumar , M.N.; Andhra Pradesh Giriprsad
The cognitive network suffers from scarcity of channels. The Unlicensed users (UU) borrow channels from the licensed users (LU). But when the LUs want them, the UUs have to stop their transmission and handle the channel back to the LUs. This results in delay in transmission of data by UUs. We propsed  an algorithm mostly focusing to meet the delay,by using a data cascading technique where the data of the UUs are stored in the intermediate nodes so that even if the transmission is interrupted, the data is not lost. The experimental results show that proposed system is better than other existing systems.
Volume: 13
Issue: 4
Page: 1233-1241
Publish at: 2015-12-01

Adaptive Fuzzy Sliding Mode Control for a Class of Nonlinear System

10.12928/telkomnika.v13i4.1898
Xue; China University of Geosciences Xiao , Zheng; Nanyang Normal University Zheng , Dong; China University of Geosciences Haobin
For a class of nonlinear system with parameter perturbation and external disturbance, adaptive fuzzy control can be used to approach the system unknown functions to reduce the control input and the steady-state error. And an adaptive switch control gain whose adaptive law is decreasing function is designed to weaken the system chattering, the switch gain of estimate will increase on the basis of the original without decreasing with the elimination of interference. If system is interferenced many times. Against the shortcomings, this paper proposes an improved adaptive law that can weaken the system chattering effectively while maintaining the strong robustness. The simulation results by tests show that this method is correct and effective.
Volume: 13
Issue: 4
Page: 1263-1269
Publish at: 2015-12-01

MOCA - Malaysia Online Coding Academy

10.11591/ijict.v4i3.pp131-136
Muaz Abdullah
Programmer is one of the hottest jobs nowadays. The need of competent programmer is increasing. But the gap between expected skillful software engineer and IT graduate skills is too big. This paper is discussing how an online integrated portal can help producing good software engineers with high programming skill and matching their competencies with job opportunity.
Volume: 4
Issue: 3
Page: 131-136
Publish at: 2015-12-01

Design and Implementation of Network Public Opinion Analysis System

10.12928/telkomnika.v13i4.2811
Ma; Xi’an International University Junhong , Liao; Xi’an International University Na
Network public opinion analysis is an important way of information analysis processing. This paper based on the research of the related technologies, designs and realizes a new network public opinion analysis system. System mainly includes network data fetching part, fetching the data processing part, analyzes the processed data part and display part of the public opinion analysis results. In the document extraction part, used the web crawler technology, Larbin web crawler to realize the collection of web content; In public opinion information analysis part, the implementation of the new topic adopts an improved Single - Pass clustering algorithm. This algorithm is using of multi-center, using the title and body of the vector to compared two-way ,that is better reflect the dynamics of public opinion topics. Finally, in the network environment of a university, we have the tests repeatedly. The results show that the new public opinion analysis system running is stable and has good efficiency. The thesis has certain value for the development of other information analysis systems in the Internet.
Volume: 13
Issue: 4
Page: 1368-1375
Publish at: 2015-12-01

A New Algorithm for Protection of Small Scale Synchronous Generators Against Transient Instability

10.11591/ijeecs.v16.i3.pp454-462
Zinat Khosravi , Alireza Saffarian
Today, installation of small generators has been increased because of their considerable benefits in distribution systems in distributed generation. One of the most important problems for transient stability is the effects of the faults of system. Small scale generators have low constant inertia and protection relays have slow performance in distribution systems. Therefore transient instability is a probable phenomenon for the systems with these generators. In this paper, dynamic response of generator has been studied in different fault conditions and then by introducing the concept of " critical fault clearing time ", the sensitivity of this time to the fault type and also fault location parameters have been studied. Then a new protection scheme has been proposed to prevent of transient instability for small scale generator. This protection scheme uses a new evolutionary algorithm based on the active power of generator and critical fault clearing time. The proposed relay can prevent of wrong and unwanted performance. Furthermore it can disconnect the generator from the system in three phase fault near of the bus-bar before its instability. Simulation results show reliable performance of the proposed relay against system transients.
Volume: 16
Issue: 3
Page: 454-462
Publish at: 2015-12-01

Text Mining Research Based on Intelligent Computing in Information Retrieval System

10.12928/telkomnika.v13i4.1788
Yong; ChongQing Technology and Business Institute Li
With the popularity and rapid development of the Internet, web text information has rapidly grown as well. To address the key problem of text mining, text clustering is investigated in this study. The shuffled frog leaping algorithm as a new type of swarm intelligence optimization algorithm can be used to improve the performance of the K-means algorithm, but the shuffled frog leaping algorithm is influenced by its moving step length. On the basis of this information, the shuffled frog leaping algorithm is improved, and the K-means clustering algorithm based on the improved shuffled frog leaping algorithm is introduced. Experiment results show that the proposed scheme can enhance the ability of searching for the optimal initial clustering center and can effectively avoid instability in the clustering results of the K-means clustering algorithm. The proposed scheme also reduces the chances of the algorithm falling into the local optimum. The performance of the proposed clustering scheme is found to be better than that of the clustering algorithm based on the shuffled frog leaping algorithm.
Volume: 13
Issue: 4
Page: 1384-1389
Publish at: 2015-12-01

Conventional DC Voltage Operating System for High Speeed Traction Power Supplies Using LLC-HPQC Control

10.11591/ijai.v4.i4.pp118-128
Ch. Lenin Babu , P. Harinath Reddy , T. Reddi Sekhar
In this paper a hybrid power quality compensator (HPQC) is proposed for compensation in cophase traction power supply and minimum dc operation voltage is achievable for high-speed traction power supply. The parameter design procedure for minimum dc operation voltage in HPQC as well as minimum voltage rating with load PF is discussed. The detailed discussions of proposed circuit configurations of HPQC are provided in section II, together with comparison with conventional RPC. In comparison with conventional railway power compensator proposed HPQC can achieve reduced dc link voltage level. It is also verified through simulations results that the LLC-HPQC would operate at the minimum voltage with the proposed parameter design. HPQC is able to provide system unbalances, reactive power, and harmonic compensation in cophase traction power with reduced operation voltage. The cophase traction power supply with proposed HPQC is suitable for high-speed traction applications.
Volume: 4
Issue: 4
Page: 118-128
Publish at: 2015-12-01

A Novel Image Segmentation Algorithm Based on Graph Cut Optimization Problem

10.12928/telkomnika.v13i4.1178
Zhang; Chongqing University Guang-hua , Xiong; Chongqing University Zhong-yang , Li; Chongqing University Kuan , Xing; Chongqing University Chang-yuan , Xia; Chongqing University Shu-yin
Image segmentation, a fundamental task in computer vision, has been widely used in recent years in many fields. Dealing with the graph cut optimization problem obtains the image segmentation results. In this study, a novel algorithm with weighted graphs was constructed to solve the image segmentation problem through minimization of an energy function. A binary vector of the segmentation label was defined to describe both the foreground and the background of an image. To demonstrate the effectiveness of our proposed method, four various types of images were used to construct a series of experiments. Experimental results indicate that compared with other methods, the proposed algorithm can effectively promote the quality of image segmentation under three performance evaluation metrics, namely, misclassification error rate, rate of the number of background pixels, and the ratio of the number of wrongly classified foreground pixels.
Volume: 13
Issue: 4
Page: 1337-1342
Publish at: 2015-12-01

Alternative Technique reducing complexity of Maximum Attribute Relation

10.12928/telkomnika.v13i4.2179
Iwan; Universitas Ahmad Dahlan Tri Riyadi Yanto , Imam; Universitas Ahmad Dahlan Azhari
Clustering refers to the method grouping the large data into the smaller groups based on the similarity measure. Clustering techniques have been applied on numerical, categorical and mix data. One of the categorical data clustering technique based on the soft set theory is Maximum Attribute Relation (MAR). The MAR technique allows calculating all of pair multi soft set made. However, the computational complexity is still an issue of the technique. To overcome the drawback, the paper proposes the alternative algorithm to decrease the complexity so get the faster response time. In this paper, to get the similar results as MAR without calculating all pair of soft set is proved. The alternative algorithm is implemented in MATLAB Software, and then experimental is run on the 10 benchmark datasets. The results show that the alternative algorithm improves the computational complexity in term of response time up to 36.46%
Volume: 13
Issue: 4
Page: 1361-1367
Publish at: 2015-12-01

Energy-efficient Routing Model Based on Vector Field Theory for Large-scale Wireless Sensor Networks

10.12928/telkomnika.v13i4.1847
Ming; Nanjing University of Science and Technolog Li , Huanyan; Nanjing University of Science and Technolog Qian , Min; California State University Northridge Xu
Routing design is a key issue for large-scale wireless sensor networks (WSNs). Energy consumption associated with allocated resources should be considered. This paper proposes the integration of an energy-efficient model, which is based on vector field theory, in large-scale WSNs. Source nodes in WSNs have the characteristics of source points in a vector field, whereas sink nodes could be characterized as gathering points. Our scheme demonstrates that we can solve a set of partial differential equations in electrostatic theory to determine the routes that result in energy efficiency. Thus, the routing problem in WSN for energy efficiency becomes a typical PDE solution. Our simulation results show significant improvement in energy consumption. Compared with the traditional shortest path approach, the proposed model shows considerable improvement in the lifetime of the network.
Volume: 13
Issue: 4
Page: 1251-1262
Publish at: 2015-12-01

Recognition of Emotions in Video Clips: The Self-Assessment Manikin Validation

10.12928/telkomnika.v13i4.2735
Dini; Kulliyyah of Information and Communication Technology Handayani , Abdul; Kulliyyah of Information and Communication Technology Wahab , Hamwira; Kulliyyah of Information and Communication Technology Yaacob
Many research domains use video contents as stimuli for study on human emotions. A video content within a particular genre or a specific theme evokes dynamic emotions that are highly useful in many research fields. The present study proposed a set of video-clip stimuli that embody four emotions under specific genres of movies, namely happiness, calmness, sadness and fear. Two experiments (a preliminary and a validation) were conducted in order to validate the video clips. Self-Assessment Manikin was utilized to rate the videos. All the video clips were rated with respect to valence and arousal judgment. In the preliminary experiment, the video clips were rated in terms of how clearly the expected emotions were evoked. The validation experiment was conducted to confirm the results from preliminary experiment, and only video clips with high recognition rates were included into data set.
Volume: 13
Issue: 4
Page: 1343-1351
Publish at: 2015-12-01

A New Strategy of Direct Access for Speaker Identification System Based on Classification

10.12928/telkomnika.v13i4.2017
Hery; Data and Software Engineering Research Group School of Electrical Engineering and Informatics, Institut Teknologi Bandung Heryanto , Saiful; Data and Software Engineering Research Group School of Electrical Engineering and Informatics, Institut Teknologi Bandung Akbar , Benhard; Data and Software Engineering Research Group School of Electrical Engineering and Informatics, Institut Teknologi Bandung Sitohang
In this paper, we present a new direct access strategy for speaker identification system. DAMClass is a method for direct access strategy that speeds up the identification process without decreasing the identification rate drastically. This proposed method uses speaker classification strategy based on human voice’s original characteristics, such as pitch, flatness, brightness, and roll off. DAMClass decomposes available dataset into smaller sub-datasets in the form of classes or buckets based on the similarity of speaker’s original characteristics. DAMClass builds speaker dataset index based on range-based indexing of direct access facility and uses Nearest Neighbor Search, Range-Based Searching, and Multiclass-SVM Mapping as its access method. Experiments show that the direct access strategy with Multiclass-SVM algorithm outperforms the indexing accuracy of Range-Based Indexing and Nearest Neighbor for one to nine percent. DAMClass is shown to speed up the identification process 16 times faster than sequential access method with 91.05% indexing accuracy.
Volume: 13
Issue: 4
Page: 1390-1398
Publish at: 2015-12-01

Power Characteristics of Wireless Charging for Sensor Networks in Tunnels

10.12928/telkomnika.v13i4.3105
Xiaoming; China University of Mining and Technology Liu , Enjie; China University of Mining and Technology Ding , Duan; China University of Mining and Technology Zhao , Youfang; China University of Mining and Technology Yang
In order to generate wireless microwave power charging technology in coal mine tunnels, it is necessary to know the power characteristics of wireless electromagnetic wave along the tunnel walls. In this paper, the experimental results of narrowband wireless electromagnetic wave propagation measurements are presented, and a statistical model of the power characteristics at 2.4 GHz in real rectangular mine tunnels is proposed. Two standard half-wave dipole antennas were used to perform the field experiments in tunnels with different wall materials. A 10-meter wireless charging distance belongs to the free-space propagation zone. The path loss exponents rely heavily on the location of the receiver and antenna polarizations. To obtain more power, the locations of the receiver should match the corresponding polarizations.
Volume: 13
Issue: 4
Page: 1180-1186
Publish at: 2015-12-01
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