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28,593 Article Results

Fault Identification of In-Service Power Transformer using Depolarization Current Analysis

10.11591/.v7i2.pp559-567
M.A. Talib , N.A. Muhamad , Z.A. Malek , B.T. Phung
Preventive diagnostic testing of in-service power transformers require system outage and expert’s knowledge and experiences in interpreting the measurement results. The chemical oil analysis may cause significant variance to measurement results due to the different practices in oil sampling, storage, handling and transportation. Thus, a cost effective measuring technique by means of a simpler method that is able provide an accurate measurement results is highly required. The extended application of Polarization and Depolarization Current (PDC) measurement for characterization of different faults conditions on in-service power transformer has been presented in this paper. The oil sample from in-service power transformers with normal and 3 different faults type conditions were sampled and tested for Dissolved Gases Analysis (DGA) and PDC measurement. The DGA results was used to confirm type of faults inside the transformer while the PDC pattern of oil with normal, partial discharge, overheating and arcing were correlated to the oil sample conditions. The analysis result shows that depolarization current provides significant information to defferenciate fault types in power transformer. Thus this finding provides a new alternative in identifying incipient faults and such knowledge can be used to avoid catastrophic failures of power transformers.
Volume: 7
Issue: 2
Page: 559-567
Publish at: 2017-04-01

An Accurate Performance Analysis of Hybrid Efficient and Reliable MAC Protocol in VANET under Non-saturated Conditions

10.11591/.v7i2.pp999-1011
Akram A. Almohammedi , Nor K. Noordin , A. Sali , Fazirulhisyam Hashim , Abdulmalek Al-Hemyari
Vehicular Ad Hoc Networks (VANETs) is a technology supporting two types of applications, safety and service applications with higher and lower priorities respectively. Thereby, Medium Access Control (MAC) protocol is designed to provide reliable and efficient data broadcasting based on prioritization. Different from the IEEE 1609.4 (legacy), HER-MAC protocol is a new multi-channel MAC proposed for VANETs, offering remarkable performance with regards to safety applications transmission. This paper focuses on the analysis of packet delivery ratio of the HER-MAC protocol under non-saturated conditions. 1-D and 2-D Markov chains have been developed for safety and non-safety applications respectively, to evaluate mathematically the performance of HER-MAC protocol. The presented work has taken into account the freezing of the backoff timer for both applications and the backoff stages along with short retry limit for non-safety applications in order to meet the IEEE 802.11p specifications. It highlights that taking these elements into consideration are important in modeling the system, to provide an accurate estimation of the channel access, and guarantees that no packet is served indefinitely. More precise results of the system packet delivery ratio have been yield. The probability of successful transmission and collisions were derived and used to compute the packet delivery ratio. The simulation results validate the analytical results of our models and indicate that the performance of our models outperformed the existing models in terms of the packet delivery ratio under different number of vehicles and contention window.
Volume: 7
Issue: 2
Page: 999-1011
Publish at: 2017-04-01

Hybrid Low Complex near Optimal Detector for Spatial Modulation

10.11591/.v7i2.pp818-822
P. Rajani Kumari , K. Chenna Kesava Reddy , K.S. Ramesh
In our previous work maximum throughput in multi stream MIMO is analyzed by overcoming the inter antenna interference. To mitigate the Inter antenna interference spatial modulation can be used. Spatial Modulation(SM) aided MIMO systems are the emerging MIMO systems which are low complex and energy efficient. These systems additionally use spatial dimensions for transmitting information. In this paper a low complex detector based on matched filter is proposed for spatial modulation to achieve near maximum likelihood performance while avoiding exhaustive ML search since MF based detector exhibits a considerable reduced complexity since activated transmitting antenna and modulated amplitude phase modulation constellation are estimated separately. Simulation results show the performance of the proposed method with optimal ML detector, MRC and conventional matched filter methods.
Volume: 7
Issue: 2
Page: 818-822
Publish at: 2017-04-01

Self-Healing Properties of Silicone Rubber Against Relative Humidity and Nanofiller

10.11591/ijeecs.v6.i1.pp166-171
Izzah Hazirah Zakaria , Muhammad Taufik Kamaruddin , Yanuar Z. Arief , Mohd Hafizi Ahmad , Noor Azlinda Ahmad , Nor Asiah Muhamad , Zuraimy Adzis
A well-prepared abstract enables the reader to identify the basic content of a document quickly and accurately, to determine its relevance to their interests, and thus to decide whether to read the document in its entirety. The Abstract should be informative and completely self-explanatory, provide a clear statement of the problem, the proposed approach or solution, and point out major findings and conclusions. The Abstract should be 100 to 150 words in length. The abstract should be written in the past tense. Standard nomenclature should be used and abbreviations should be avoided. No literature should be cited. The keyword list provides the opportunity to add keywords, used by the indexing and abstracting services, in addition to those already present in the title. Judicious use of keywords may increase the ease with which interested parties can locate our article.
Volume: 6
Issue: 1
Page: 166-171
Publish at: 2017-04-01

A Tunable Ferrofluid-based Polydimethylsiloxane (PDMS) Microchannel Inductor for Ultra High Frequency Applications

10.11591/.v7i2.pp926-932
Ahmad Hafiz Mohamad Razy , Mohd Tafir Mustaffa , Asrulnizam Abd Manaf , Norlaili Mohd Noh
In this work, a tunable ferrofluid-based polydimethylsiloxane (PDMS) microchannel inductor with high quality factor and high tuning range is proposed. For this project, PDMS is used to create a microchannel with a width and height of 0.53 mm and 0.2 mm respectively. The microchannel is then used to cover the whole design of a solenoid inductor. A solenoid inductor is designed using wire bonding technique where lines of copper and bond wires are used to form a solenoid winding on top of silicon substrate. A light hydrocarbon based ferrofluid EMG 901 660 mT with high permeability of 5.4 is used. The ferrofluid-based liquid is injected into the channel to enhance the performance of a quality factor. A 3D full-wave electromagnetic fields tool, ANSYS HFSS is used in this work to simulate the solenoid inductor. The results obtained in this work gives a quality factor of more than 10 at a frequency range of 300 MHz to 3.3 GHz (Ultra High Frequency range). The highest quality factor is 37 which occurs at a frequency of 1.5 GHz, provides a high tuning range of 112%.
Volume: 7
Issue: 2
Page: 926-932
Publish at: 2017-04-01

Maximum Power Point Tracking using Particle Swarm Optimization Algorithm for Hybrid Wind-Tidal Harvesting System on the South Coast of Java

10.11591/.v7i2.pp659-666
Fransisco Danang Wijaya , Kukuh Daud Pribadi , Sarjiya Sarjiya
This paper proposes a hybrid wind-tidal harvesting system (HWTHS). To extract maximum power from the wind and tidal, HWTHS implements particle swarm optimization (PSO) algorithm in maximum power point tracking (MPPT) method. The proposed HWTHS had been tested on the range of possible input appropriate to the characteristics of the southern coast of Java. The presented result shows that by using PSO-based MPPT algorithm, maximum power point can be achieved. Thus the efficiency of HWTHS is 92 %, 94 % in wind section and 91 % in tidal section. By using PSO-based MPPT, HWTHS can respond well to changes in wind and tidal speed, whether it's a change from low speed to a higher speed or change from high speed to lower speed wherein time to reach new steady state is ± 0.1 s. At varied wind and tidal speed, PSO algorithm can maintain Cp of the system in the range of 0.47 - 0.48 so that power can be extracted to the maximum.
Volume: 7
Issue: 2
Page: 659-666
Publish at: 2017-04-01

Radiation Pattern Performance of Unequally Linear Arrays with Parasitic Element

10.11591/ijeecs.v6.i1.pp110-115
Noor Ainniesafina Zainal , Muhammad Ramlee Kamarudin , Yoshihide Yamada , Norhudah Seman
For next generation of 5G mobile base station antennas, multibeam, multifrequency and low sidelobe characteristics requested. Simplify the feeding network will contribute a low feeder loss and frequency dependent. From the previous research by the author, low sidelobe level reported by density tapered array configuration from -13 dB to -16 dB and the result maintained for wideband operation frequency at 28 GHz, 42 GHz, and 56 GHz. However, the grating lobe has occurred due to element spacing larger than a wavelength of higher frequency (56 GHz). In this paper, an investigation was made of the performance of radiation pattern for unequally microstrip linear array antenna in frequency 42 GHz and 56 GHz by loading parasitic elements. The effect of parasitic element to the impedance, gain, and sidelobe level of unequally microstrip linear spaced tapered array also examined. The design has been simulated using Ansoft High Frequency Structural Simulator (HFSS) ver 16.0.
Volume: 6
Issue: 1
Page: 110-115
Publish at: 2017-04-01

Hungarian-Puzzled Text with Dynamic Quadratic Embedding Steganography

10.11591/.v7i2.pp799-809
Ebrahim Alrashed , Suood Suood Alroomi
Least-Significant-Bit (LSB) is one of the popular and frequently used steganography techniques to hide a secret message in a digital medium. Its popularity is due to its simplicity in implementation and ease of use. However, such simplicity comes with vulnerabilities. An embedded secret message using the traditional LSB insertion is easily decodable when the stego image is suspected to be hiding a secret message.  In this paper, we propose a novel secure and high quality LSB embedding technique. The security of the embedded payload is employed through introducing a novel quadratic embedding sequence. The embedding technique is also text dependent and has non-bounded inputs, making the possibilities of decoding infinite. Due to the exponential growth of and quadratic embedding, a novel cyclic technique is also introduced for the sequence that goes beyond the limits of the cover medium. The proposed method also aims to reduce the noise arising from embedding the secret message by reducing bits changed. This is done by partitioning the cover medium and the secret message into N partitions and artificially creating an assignment problem based on bit change criteria. The assignment problem will be solved using the Hungarian algorithm that will puzzle the secret message partition for an overall least bit change.
Volume: 7
Issue: 2
Page: 799-809
Publish at: 2017-04-01

p-Laplace Variational Image Inpainting Model Using Riesz Fractional Differential Filter

10.11591/.v7i2.pp850-857
Sridevi Gamini , S Srinivas Kumar
In this paper, p-Laplace variational image inpainting model with symmetric Riesz fractional differential filter is proposed. Variational inpainting models are very useful to restore many smaller damaged regions of an image. Integer order variational image inpainting models (especially second and fourth order) work well to complete the unknown regions. However, in the process of inpainting with these models, any of the unindented visual effects such as staircasing, speckle noise, edge blurring, or loss in contrast are introduced. Recently, fractional derivative operators were applied by researchers to restore the damaged regions of the image. Experimentation with these operators for variational image inpainting led to the conclusion that second order symmetric Riesz fractional differential operator not only completes the damaged regions effectively, but also reducing unintended effects. In this article, The filling process of damaged regions is based on the fractional central curvature term. The proposed model is compared with integer order variational models and also GrunwaldLetnikov fractional derivative based variational inpainting in terms of peak signal to noise ratio, structural similarity and mutual information.
Volume: 7
Issue: 2
Page: 850-857
Publish at: 2017-04-01

Mining Relation Extraction Based on Pattern Learning Approach

10.11591/ijeecs.v6.i1.pp50-57
Mujiono Sadikin
Semantically, objects in unstructured document are related each other to perform a certain entity relation. This certain entity relation such: drug-drug interaction through their compounds, buyer-seller relationship through the goods or services, etc. Motivated by those kind of interaction, this study proposes a method to extract those objects and their interactions. It is presented a general framework of object-interaction mining of large corpora. The framework is started with the initial step in extracting a single object in the unstructured document. In this study, the initial step is a pattern learning method that is applied to drug-label documents to extract drug-names. We utilize an existing external knowledge to identify a certain regular expressions surrounding the targeted object and the probabilities of those regular expression, to perform the pattern learning process. The performance of this pattern learning approach is promising to apply in this relation extraction area. As presented in the results of this study, the best f-score performance of this method is 0.78 f-score. With adjusting of some parameters and or improving the method, the performance can be potentially improved.
Volume: 6
Issue: 1
Page: 50-57
Publish at: 2017-04-01

Power Quality Enhancement in Grid Connected PV Systems using High Step Up DC-DC Converter

10.11591/.v7i2.pp720-728
V S Prasadarao K , K V Krishna Rao , P Bala Koteswara Rao , T. Abishai
Renewable energy sources (RES) are gaining more importance in the present scenario due to the depletion of fossil fuels and increasing power demand. Solar energy is the one of the most promising as it is clean and easily available source. The voltage obtained from the PV system is low. This voltage is increased by high step up dc-dc converter which uses only one switch leads to low switching losses and hence the efficiency of this converter is high. To get the good response this converter is operated in closed loop manner. Integration of PV system with existing grid has so many issues like distorted voltage, current and reactive power control etc. This paper presents a four leg inverter which works on hysteresis current control technique to address the power quality issues like reactive power compensation, balanced load currents and compensation of neutral current. The switching to the inverter is designed in such a way that it supplies the extra current to stabilise the current of the grid that is being supplied to the loads. Finally, the proposed technique is validated by using mat lab/Simulink software and corresponding results are presented in this paper.
Volume: 7
Issue: 2
Page: 720-728
Publish at: 2017-04-01

The Effect of Plasma-Treated Boron Nitride on Partial Discharge Characteristics of LDPE

10.11591/.v7i2.pp568-575
N.A Awang , M.H Ahmad , Y.Z. Arief , I.H. Zakaria , N.A. Ahmad
Power supply reliability is a key factor in a country economic stability. It is contributed by the reliable power distributor via transmission lines, overhead or underground cables. However, the power cables and accessories are always exposed to pre-breakdown phenomena known as partial discharges (PD) which commonly occur in microvoids, defects or protrusions inside the insulation. To improve the performance of the cable insulation against PD, nanofillers are added into the insulating materials. However, to achieve superior performance of PD resistance, the nanofillers must be homogeneously dispersed into the polymer matrices with tightly bonded interfacial zones. Therefore, this could be achieved by employing method of surface functionalization by using cold atmospheric plasma to strengthen the filler/polymer interfaces. In view of foregoing, this study investigated the effects of surface treated boron nitride (BN) nanoparticles in Low Density Polyethylene (LDPE) on the PD characteristics by following CIGRE Method II at 7 kVrms applied voltage. The phase resolved PD characteristics were performed. The results revealed that by treating the nanofillers with cold plasma, the PD resistance of LDPE were highly achieved compared with the untreated BN nanofillers.
Volume: 7
Issue: 2
Page: 568-575
Publish at: 2017-04-01

Design of Pervasive Discovery, Service and Control for Smart Home Appliances: An Integration of Raspberry Pi, UPnP Protocols and Xbee

10.11591/.v7i2.pp1012-1022
Sabriansyah Rizqika Akbar , Maystya Tri Handono , Achmad Basuki
Pervasive technology is an important feature in smart home appliances control. With pervasive technology, the user is able to discover and control every device and each service without initialization configuration and setup. Since single-board computer often used in smart home appliances, combining pervasive technology and microcomputer/single-board computer will be important to be applied and make a possibility to create a smart home system based on the requirement of it users that will be beneficial for the smart home users and the developers. This paper proposed a design of pervasive discovery, service, and control system for smart home appliances by integrating Raspberry Pi, UPnP protocols, and Xbee that able to control an RGB LED services such as switching, dimming, change color and read a temperature sensor as an example in smart home appliances. This paper enriched the raspberry Pi GPIO function to be able to control via TCP/IP network with UPnP protocol and receive information from a temperature sensor node via Xbee communication. Service control time is measured with UPnP round trip time by subtracting HTTP response arrival with HTTP request time. GPIO processing time measured at the application level by counting a timer that starts before GPIO process and ended after GPIO successfully executed.
Volume: 7
Issue: 2
Page: 1012-1022
Publish at: 2017-04-01

A Comprehensive Review of Fault Location Methods for Distribution Power System

10.11591/ijeecs.v6.i1.pp185-192
N Gana , NF Ab Aziz , Z Ali , H Hashim , Bahisham Yunus
Fault on distribution system does not only affect the reliability of power supply, but also contribute to increasing operational and maintenance cost borne by the utilities. Throughout the years, various methods have been studied and practiced to solve problems related to the fault location in the distribution system. In this paper, the fault location methods are reviewed and summarised according to their categories. The fault location methods discussed in this paper are based on literature studies of outage mapping and field measurement for the distribution system. Furthermore, the component which influences the fault location methods such as unbalanced system, capacitance effects, distributed generation, and distribution topology are related to the explanation of the method. Finally, the field measurements are presented as in comparison which will clarify the effectiveness and the establishment of each method.
Volume: 6
Issue: 1
Page: 185-192
Publish at: 2017-04-01

FPGA Implementation of Real Time String Colour Detection

10.11591/ijeecs.v6.i1.pp139-147
Teo Sje Yin , P. Ehkan , Soon Voon Siew , Lam Chee Yuen , M. N.M.Warip
A Machine vision for string detection is useful technologies which benefit to the industries such as food production. It reduces the risk that can harmful to our health and it can do work more accurate and efficient. The algorithm used is a colour detection which determines the colour of string and background subtraction for filter process by using the threshold range values. The target of detection focuses on plastic string with two different colours; pink and yellow strings. The threshold values used in hardware detection are ranged from 158 to 175 and 3 to 35 for pink and yellow string colours, respectively. The result shows that an object tied with strings is able to be detected and captured by using this system. Overall, this project is successfully developed and achieved the goal for real time detecting a string which is implemented on FPGA.
Volume: 6
Issue: 1
Page: 139-147
Publish at: 2017-04-01
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