Articles

Access the latest knowledge in applied science, electrical engineering, computer science and information technology, education, and health.

Advanced Search
Filter Icon

Filters article

Years

FAQ Arrow
Single Year
Range Year
0
0

Source Title

FAQ Arrow

Authors

FAQ Arrow

28,188 Article Results

Enhanced Antenna Design for Rectenna Application in the 2.45 GHz ISM Band

10.12928/telkomnika.v14i4.4137
Sharif; Universiti Teknikal Malaysia Melaka (UTeM) Ahmed , Zahriladha; Universiti Teknikal Malaysia Melaka (UTeM) Zakaria , Mohd Nor; Universiti Teknikal Malaysia Melaka (UTeM) Husain , Azahari; Universiti Teknikal Malaysia Melaka (UTeM) Salleh , Ammar; Universiti Teknikal Malaysia Melaka (UTeM) Alhegazi
In this paper a two layers microstrip antenna design at 2.45 GHz ISM band with Harmonic rejection filter embedded on the ground plane is presented. The two roger substrates with relative permittivity of 2.2 are separated by an air gap which enhances the antenna gain. The design is simulated using Computer Simulation Technology (CST) Studio Suite 2015. Different aperture couplings slots such as rectangular and triangular aperture coupling slots are studied and compared. It is found that the antenna with triangular aperture coupling slot enhances the antenna performance by suppressing 2nd and 3rd harmonics at 5 GHz and 8 GHz, respectively, increasing the antenna gain and providing a better circular polarization behavior. The simulated antenna design achieves a gain of 9 dB, return loss of -23.6dB, axial ratio of 1.27dB and axial-ratio bandwidth of 40.8% (2 ~ 3 GHz). The proposed antenna shows an enhancement in the antenna performance which makes it a suitable candidate for rectifying antenna or rectenna application as it can increase the total conversion efficiency resulting in a high output DC voltage used to power low power electronic and electrical devices such as wireless sensor.
Volume: 14
Issue: 4
Page: 1338-1344
Publish at: 2016-12-01

Combined Beamforming with Orthogonal Space Time Block Code for MIMO-OFDM with Simple Feedback

10.11591/ijeecs.v4.i3.pp580-585
Hala M. Abd Elkader , Gamal M. Abdel-Hamid , Adly Tag El-Dien , Asmaa A. Nassif
In this paper, we introduce a proposed scheme to enhance the performance of orthogonal space time block code (OSTBC) with four time slots and two antennas by combing OSTBC with random beamforming to can use it in the downlink transmission for a mobile system.  Multiple-input multiple-output orthogonal frequency-division multiplexing (MIMO-OFDM) system has been recognized as one of the most promising techniques to achieve a good service and increase data rate in the next generation (4&5G) broadband wireless communications. So, we apply Space time block code (STBC) for MIMO-OFDM system with linear decoding.  Also, we perform STBC with beamforming for MIMO-OFDM system to improve the performance of a system. Simulation results show that the beamforming improves bit error rate (BER) performance of OSTBC and STBC-OFDM for different types of modulation and diversity.
Volume: 4
Issue: 3
Page: 580-585
Publish at: 2016-12-01

A Modelling and Simulation of a Sensorless Control of Five-phase PMSM Drives using Multi-dimension Space Vector Modulation

10.12928/telkomnika.v14i4.3996
Kamel; An-Najah National Univeristy Saleh , Mark; Nottingham University Sumner
This paper is under in-depth investigation due to suspicion of possible plagiarism on a high similarity indexThis paper introduces a new method to track the saturation saliency for position measurement of a five-phase PMSM motor fed by a five-phase inverter through measuring the dynamic current response of the motor line currents due to the IGBT switching actions. The new method uses only the fundamental PWM waveform obtained using the multi-phase space vector pulse width modulation (i.e there is no modification to the operation of the five-phase inverter) similar to the fundamental PWM method proposed for a three-leg inverter. Simulation results are provided to verify the effectiveness of the proposed strategy for saliency tracking of a five-phase PMSM motor driven by five-phase inverter over a wide speed ranges under different load conditions.
Volume: 14
Issue: 4
Page: 1269-1283
Publish at: 2016-12-01

Region Based Image Retrieval Using Ratio of Proportional Overlapping Object

10.12928/telkomnika.v14i4.4289
Agus Zainal; Institut Teknologi Sepuluh Nopember Arifin , Rizka Wakhidatus; Institut Teknologi Sepuluh Nopember Sholikah , Dimas Fanny; Institut Teknologi Sepuluh Nopember H. P. , Dini Adni; Institut Teknologi Sepuluh Nopember Navastara
In Region Based Image Retrieval (RBIR), determination of the relevant block in query region is based on the percentage of image objects that overlap with each sub-blocks. But in some images, the size of relevant objects are small. It may cause the object to be ignored in determining the relevant sub-blocks. Therefore, in this study we proposed a system of RBIR based on the percentage of proportional objects that overlap with sub-blocks. Each sub-blocks is selected as a query region. The color and texture features of the query region will be extracted by using HSV histogram and Local Binary Pattern (LBP), respectively. We also used shape as global feature by applying invariant moment as descriptor. Experimental results show that the proposed method has average precision with 74%.
Volume: 14
Issue: 4
Page: 1608-1616
Publish at: 2016-12-01

A Practical Coordinated Trajectory Tracking for A Group of Mixed Wheeled Mobile Robots with Communication Delays

10.12928/telkomnika.v14i4.3056
Sisdarmanto; Universitas Islam Indonesia Adinandra , Dwi Ana; Universitas Islam Indonesia Ratnawari
Coordination between a specific mobile robot type has been widely investigated, e.g coordination between unicycles. To extend the applicability of the system, a coordinated trajectory tracking of mixed type of mobile robots is considered. We prove that if a certain type of wheeled mobile robot is able to individually track its own reference, then coordination in tracking with other type of robots can be achieved simply by sharing individual tracking errors. Using two types of wheeled mobile robots, namely unicycle type (a nonholonomic mobile robot) and omni wheels type (a holonomic mobile robot), a coordinated control algorithm can achieve a global asymptotically stable condition of the error dynamics of the systems. Under bidirectional communication between robots as a constraint, the group is able to maintain individual tracking while coordinating the movements with other robots regardless occurring perturbations in the system and delays in communication channels. Simulation results suggest that information sharing between the robots increase the robustness in coordinating individual trajectories. Results also show that delays cause drop in performance similar to the case of no information sharing.
Volume: 14
Issue: 4
Page: 1397-1407
Publish at: 2016-12-01

SVM Parameter Optimization using Grid Search and Genetic Algorithm to Improve Classification Performance

10.12928/telkomnika.v14i4.3956
Iwan; Politeknik Elektronika Negeri Surabaya Syarif , Adam; University of Southampton Prugel-Bennett , Gary; University of Southampton Wills
Machine Learning algorithms have been widely used to solve various kinds of data classification problems. Classification problem especially for high dimensional datasets have attracted many researchers in order to find efficient approaches to address them. However, the classification problem has become very complicated and computationally expensive, especially when the number of possible different combinations of variables is so high. Support Vector Machine (SVM) has been proven to perform much better when dealing with high dimensional datasets and numerical features. Although SVM works well with default value, the performance of SVM can be improved significantly using parameter optimization. We applied two methods which are Grid Search and Genetic Algorithm (GA) to optimize the SVM parameters. Our experiment showed that SVM parameter optimization using grid search always finds near optimal parameter combination within the given ranges. However, grid search was very slow; therefore it was very reliable only in low dimensional datasets with few parameters. SVM parameter optimization using GA can be used to solve the problem of grid search. GA has proven to be more stable than grid search. Based on average running time on 9 datasets, GA was almost 16 times faster than grid search. Futhermore, the GA’s results were slighlty better than the grid search in 8 of 9 datasets.
Volume: 14
Issue: 4
Page: 1502-1509
Publish at: 2016-12-01

Designing of Medical processor unit for Intelligent network-based Medical usage

10.11591/ijeecs.v4.i3.pp532-537
P. ILA Chandana Kumari , P. Gayathri , N. Rajesh , Syed Umar , G. Chandra Sekhar , Azeem Mohammed Abdul
This medical design conventions of books and deductive method (MPU). the development of research and the success of many already, we have found the cause of architecture MPU. On the unique features of the processor in question it is coded in different areas of medicine (MOPC). working from a very close bilateral processor MPU. Each issue has a special feature code for the hardware supply chain on the steps and produce a special version of the code and the victim (s). Illness, Doctor MOPC mph dismounted and made a series of sub-processes, and to launch the second law of medical devices. If the computer system of a victim and has a specific digital for logic, and victims of medical devices that operate in the blood, tissues, operating theaters, medical staff, medical costs and variables, etc. We follow the process that the patient design of medical networks and overlapping and development computer.
Volume: 4
Issue: 3
Page: 532-537
Publish at: 2016-12-01

Assessing State of the Art on Artificial Neural Network Paradigms for Level of Eutrophication Estimation of Water Bodies

10.11591/ijai.v5.i4.pp135-142
Tushar Anthwal , M K Pandey
With growing power of computer and blend of intelligent soft wares, the interpretation and analytical capabilities of the system had shown an excellent growth, providing intelligence solutions to almost every computing problem. In this direction here we are trying to identify how different geocomputation techniques had been implemented for estimation of parameters on water bodies so as to identify the level of contamination leading to the different level of eutrophication. The main mission of this paper is to identify state-of-art in artificial neural network paradigms that are prevailing and effective in modeling and combining spatial data for anticipation. Among this, our interest is to identify different analysis techniques and their parameters that are mainly used for quality inspection of lakes and estimation of nutrient pollutant content in it, and different neural network models that offered the forecasting of level of eutrophication in the water bodies. Different techniques are analyzed over the main steps;-assimilation of spatial data, statistical interpretation technique, observed parameters used for eutrophication estimation and accuracy of resultant data.
Volume: 5
Issue: 4
Page: 135-142
Publish at: 2016-12-01

The Optimal High Performance Computing Infrastructure for Solving High Complexity Problem

10.12928/telkomnika.v14i4.3586
Yuliant; Telkom University Sibaroni , Fitriyani; Telkom University Fitriyani , Fhira; Telkom University Nhita
The high complexity of the problems today requires increasingly powerful hardware performance. Corresponding economic laws, the more reliable the performance of the hardware, it will be comparable to the higher price. Associated with the high-performance computing (HPC) infrastructures, there are three hardware architecture that can be used, i.e. Computer Cluster, Graphical Processing Unit (GPU), and Super Computer. The goal of this research is to determine the most optimal of HPC infrastructure to solve high complexity problem. For this reason, we chose Travelling Salesman Problem (TSP) as a case study and Genetic Algorithm as a method to solve TSP. Travelling Salesman Problem is belong often the case in real life and has a high computational complexity. While the Genetic Algorithm (GA) is belong a reliable algorithm to solve complex cases, but has the disadvantage that the time complexity level is very high. In some research related to HPC infrastructure comparison, the performance of multi-core CPU single node for data computation has not been done. Whereas the current development trend leads to the development of PCs with higher specifications like this. Based on the experiments results, we conclude that the use of GA is very effective to solve TSP. the use of multi-core single-node in parallel for solving high complexity problems as far as this is still better than the two other infrastructure but slightly below compare to multi-core single-node serially, while GPU deliver the worst performance compared to others infrastructure. The utilization of a super computer PC for data computation is still quite promising considering the ease of implementation, while the GPU utilization for the purposes of data computing is profitable if we only utilize GPU to support CPU for data computing.
Volume: 14
Issue: 4
Page: 1545-1551
Publish at: 2016-12-01

Email Classification Using Adaptive Ontologies Learning

10.12928/telkomnika.v14i4.4026
Suma; JJT University, Rajasthan T , Kumara; Nagarjuna College of Engg. & Technology, Visvesvaraya Technological University (VTU) Swamy Y S
Email is a way of communication for the today’s internet world, private and government sector or public sector all are used email for communication with their clients. They can freely send number of mail to their client without disturbing them. Now a day email communication is also a way of advertising, some mail is also spam, lots of social mails are there. Categorization and handling lots of email is an important task for the researches, as they all are working in this field by using the Natural language processing and ontology extraction process. User get frustrated for handling lots of mails and reading those for finding there is any important mail, sometime user delete lots of mail without reading and in that case may be some important mail which contain the important information may be about meeting, seminar etc. is also deleted. For avoiding these scenarios here auto updation of schedule calendar procedure is proposed by the author. Concept extraction and clustering of concept is done based on fuzzy logic, similar mail pattern is grouped in a same cluster if similarity is less than threshold value a new cluster is defined for that. From the extracted concept author establish the relationship between them and generate the result. Computation overhead is also calculated for different set of mails and finds that it takes very less time in computing large email data set.
Volume: 14
Issue: 4
Page: 1472-1479
Publish at: 2016-12-01

Novel Design of LLC Resonant Converter with Peak Gain Adjustment

10.12928/telkomnika.v14i4.3306
P.; Chaitanya Bharathi Institute of Technology Kowstubha , K.; Chaitanya Bharathi Institute of Technology Krishnaveni , K. Ramesh; G.Narayanamma Institute of Technology and Science Reddy
The main advantages of a half-bridge LLC resonant DC/DC converter having two inductors (LL) and a single capacitor (C) compared to the other load resonant converters are its less amount of circulating currents and large bandwidth for Zero Voltage Switching (ZVS). It also has the advantage of limited tuning of operating frequency to get the regulated output when variable frequency control method is implemented on the converter. This DC/DC converter is widely used in server and telecom applications due its higher efficiency and reliability. In this paper, a novel design using peak gain adjustment is proposed for a LLC resonant DC/DC converter with a design example of 400V/12V-5A used in server based applications. For the specifications of the converter mentioned, an experimental set up is built and evaluated with the Texas instruments power switch FSFR 2100 IC in closed loop configuration. The experimental results proved an improved efficiency of 94% for the converter with the novel design proposed.
Volume: 14
Issue: 4
Page: 1242-1252
Publish at: 2016-12-01

Laser-Induced Color Marking of Titanium Alloy

10.12928/telkomnika.v14i4.4177
Li; Shandong University Chunling , Lu; Shandong University Changhou
A Nd:YAG nanosecond laser was utilized in the laser color marking of  titanium alloy substrates. It was focused on how several laser parameters, such as pumping current, delay between the effective vector step, laser line spacing, Q-switch frequency and focal plane offset, affected the resulting colors, and the influence of the resulting colors on the substrate. Firstly, single-factor experiments were carried out. Then the dark blue square pattern and two samples were analyzed using an environmental scanning electron microscope (ESEM) and X-ray diffractometer (XRD) respectively. Results clearly showed that the Nd:YAG nanosecond laser can induce multiple colors on titanium alloy substrates and all the five parameters had an effect on the resulting colors significantly. The dark blue square pattern didn’t induce internal stresses within the substrate material, so  the influence of the resulting colors on the substrate is negligible.
Volume: 14
Issue: 4
Page: 1313-1320
Publish at: 2016-12-01

Analysis of Transmission Lightning Arrester Locations Using Tflash

10.12928/telkomnika.v14i4.3792
M. I.; Universitas Sriwijaya Jambak , Z.; Universitas Sriwijaya Nawawi , R.F.; Universitas Sriwijaya Kurnia , Z.; Universiti Teknologi Malaysia Buntat , M. A. B.; Universitas Sriwijaya Sidik , Y. Z.; Universiti Teknologi Malaysia Arief , A. A.; Tenaga Nasional Berhad Wahab , Z.; Tenaga Nasional Berhad Ramli , M. E.; Tenaga Nasional Berhad Ramly
Tropical countries with extensive lightning activity, such as Malaysia, encounter numerous problems on their electrical transmission and distribution systems. Many overhead lines trip because of back flashover of lightning and shielding failures of the grounding system. To overcome the problem and improve transmission line performance, a detailed lightning study is required to analyse the corresponding lines and determine the best location for transmission line arrester (TLA) installation. We used TFlash to analyse a TLA installation on a 132-kV SSWW-BBST overhead transmission line system located in Selangor, Malaysia. Based on the results, the installation of the TLA at the optimum quantity and at appropriate towers have reduced the number of lines that trip.
Volume: 14
Issue: 4
Page: 1228-1234
Publish at: 2016-12-01

Heterogeneous Information Knowledge Construction Based on Ontology

10.12928/telkomnika.v14i4.4787
Jianhou; Kunming University of Science and Technology Gan , Gang; Kunming University of Science and Technology Xie , Yongzheng; North China University of Technology Yan , Wanquan; Curtin University of Technology Liu
Describing and representing multi-source and heterogeneous knowledge is a popular research topic in recent years. After investigating knowledge forming process based on multi-source heterogeneous information resources, we present a new approach in which different information resources are put into a mutual RDF(S) data model, and semantic reasoning of RDF(S) is conducted. Moreover, a knowledge base construction framework for multi-source heterogeneous information source with combination of Ontology knowledge model is put forward, and an algorithm of knowledge base construction is also proposed, in which the core issues are knowledge inclusion and updating. Then the time complexity of our algorithm is analyzed. Finally, in order to solve the heterogeneous, and uneven horizontal of geographical distribution of ethnic minority information resources in Yunnan Province, we use the proposed method to construct a domain knowledge base for ethnic minority information resources, and use this model to evaluate the efficiency for the knowledge inclusion algorithm in responding time and indexing responding time for different data resources in our experiments.
Volume: 14
Issue: 4
Page: 1617-1628
Publish at: 2016-12-01

Virtual Stability Estimator Model for Three Phase Power System Network

10.11591/ijeecs.v4.i3.pp520-525
K. Nithiyananthan , Simson Samson Raja , R Sundar , A Amudha
The main objective of this research work is to develop a simple power systems steady state stability estimator in LabView for three phase power system network. LabVIEW based power systems stability estimator has been chosen as the main platform because it is a user friendly and easy to apply in power systems. This research work is intended to simultaneously acclimate the power system engineers with the utilization of LabVIEW with electrical power systems. This proposed work will discuss about the configuration and the improvement of the intelligent instructional VI (virtual instrument) modules in power systems for power systems stability solutions. In the proposed model power systems stability has been carried out and model has been developed such that it can accommodate the latest versions of power systems stability algorithms.
Volume: 4
Issue: 3
Page: 520-525
Publish at: 2016-12-01
1 2 3
...
1879 1880
Show 1494 of 1880

Discover Our Library

Embark on a journey through our expansive collection of articles and let curiosity lead your path to innovation.

Explore Now
Library 3D Ilustration