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29,061 Article Results

Design of Handphone Wireless Charger System Using Omnidirectional Antenna

10.12928/telkomnika.v15i4.5819
Anton; Ahmad Dahlan Univerity, Indonesia Yudhana , Fahrizal; Universitas Ahmad Dahlan, Indonesia Djohar
Using cable as power transmission medium cause problem in flexibility and aesthetics. Wireless power transmission for charging handphone releasednowadays still using antenna with radiation pattern focus in one direction, that is just toward the top, and if the antenna was shifted then power transmitted will be lose. The purpose of this research is to produce wireless power charger system used for charging handphone power using resonator based on omnidirectional antenna and test the performance. The device in this research was designed in two main part, that is transmitter and receiver. In transmission section, there is power supply used for supplying power to oscillator to generate oscillating signal in the form of electrical power to be transmitted to receiver via antenna in the form magnetic field. In receiver section, receiver antenna received the power transmitted that is still in the reach of magnetic field generated by transmitter. The power that is still in the form of oscillating signal, then stabilized for the purpose of handphone power using rectifier and voltage regulator. Design has been made successfully to the form of handphone battery power wireless chargerusing omdirectional antenna which consist of two main part, that is transmitter and receiver. The transmitted power is 3.058 watt with frequency 714 KHz, and receiver received the power and then stabilized the signal to produce output power 58.706 miliwatt. This device can transmit power in all directions horizontally (angle 360°). This device also tested with some kind of obstacle, with the result almost all obstacle still could transmit the power except metal.
Volume: 15
Issue: 4
Page: 1757-1765
Publish at: 2017-12-01

Compact Stepped Impedance Resonator Bandpass Filter with Tunable Transmission Zeros

10.12928/telkomnika.v15i4.6695
Rezki El; Universitas Brawijaya, Indonesia Arif , Muhammad Aziz; Universitas Brawijaya, Indonesia Muslim , Sholeh Hadi; Universitas Brawijaya, Indonesia Pramono
This paper proposes a compact microstrip bandpass filter (BPF) with tunable transmission zeros, narrow bandwidth and low insertion loss. A λ/4 stepped impedance resonator (SIR) with two additional via holes has been adopted to obtain a compact size and a pair of transmission zero (TZ). Furthermore, three techniques have been developed to create a pair of controllable transmission zeros on both side of each passband.  The TZ can be controlled by adjusting either magnetic or electric coupling. The measured return losses and insertion loss is larger than 18 dB and 2.2 dB respectively. The overall size of the proposed design filter is 5.3mm x 5.5mm without considering the feeding lines.
Volume: 15
Issue: 4
Page: 1689-1692
Publish at: 2017-12-01

Theoretical Analysis of a Two-stage Sagnac loop filter using Jones Matrices

10.11591/ijece.v7i6.pp2950-2957
N. A. B. Ahmad , S. H. Dahlan , N. A. Cholan
In this work, a theoretical analysis of a Sagnac loop filter (SLF) with two-stage polarization maintaining fibers (PMFs) and polarization controllers (PCs) is presented. The transmission function of this two-stage SLF is calculated in detail by using Jones matrix. The calculation is performed in order to investigate the filtering characteristics. The theoretical results show that the wavelength interval is depending on the dynamic settings of the length of the PMFs and the polarization angle of the PCs. By changing the polarization angle of the PCs, a multiple of single, dual or triple wavelength in each channel can be achieved. Based on this study, a flat multiwavelength spectrum can be obtained by adjusting the PMFs and the PCs in the two-stage SLF. This finding significantly contributes to the generation of multiwavelength fiber laser (MWFL) that can be used for many optical applications.
Volume: 7
Issue: 6
Page: 2950-2957
Publish at: 2017-12-01

GIS Based Satellite Image Denoising Using Curvelet Transform

10.11591/ijeecs.v8.i3.pp654-656
S. Sinthuja , Santhosh Saravanan
Generally, satellite images contain very significant information about geographical features such as rivers, roads, building and bridges etc of the earth. Geographic Information System (GIS) requires these features for automatic detection and it has been corrupted by various types of noise. Curvelet Transform (CT) is used in the proposed system for denoising the images. Advantages of multi resolution image such as line, compatibility of human visual system and edge detection are provided. Then K-Means clustering is used in this system for segmentation purpose after the pre processing done.First, K-Means algorithm is used for segmenting background and water then extraction of bridges is done based on pixel intensity difference.   
Volume: 8
Issue: 3
Page: 654-656
Publish at: 2017-12-01

Performance of Modified S-Transform for Power Quality Disturbance Detection and Classification

10.12928/telkomnika.v15i4.7230
Faridah; Universiti Tun Hussien Onn Malaysia Hanim M. Noh , Munirah; Universiti Tun Hussien Onn Malaysia Ab. Rahman , M.; Universiti Teknikal Malaysia Melaka Faizal Yaakub
Detection and classification of power quality (PQ) disturbances are an important consideration to electrical utility companies and many industrial customers so that diagnosis and mitigation of such disturbance can be implemented quickly. Power quality signal consists of stationary and non-stationary events which need a robust signal processing technique to analyse the signals. In this paper, Modified STransform (MST) was used to analyse single and multiple power quality signals. MST is a modified version of S-transform with improved time-frequency resolution. The power quality signals that are considered in this study are voltage swell, sag, interruption, harmonic, interharmonic, transient, sag plus harmonic and swell plus harmonics. The performance of the proposed method has been studied under noisy and unnoisy condition. Hard thresholding technique has been applied with MST while analysing noisy PQ signals. The result shows that MST is able to give higher classification rate with better time and frequency distribution (TFD) spectrum of the PQ disturbances. 
Volume: 15
Issue: 4
Page: 1520-1529
Publish at: 2017-12-01

Handheld Secured Electronic Doorstep Banking System that allows Cash Withdrawal and Deposit Facility for Remote and Rural Areas

10.11591/ijeecs.v8.i3.pp705-708
G. Kannan
The bank's similar massive customer base isn't inside the urban level notwithstanding, inside the repeatedly pretermitted rustic territories. Light errands like getting without end to the ATM and withdrawing trade cause people out towns lose their working hours and, thus, miss a major live of their monetary profit moreover. In this paper a secured handheld doorstep managing an account industry alluded to as Micro-bank machine is proposed to concede administration to the buyers in provincial ranges and remote places, for example, towns. The arranging may likewise be worked inside and on the most distant side of the consistent managing an account hours. The primary point of the handheld machine is to control managing an account administration like cash withdrawals and cash store while not the individual always pointing to a bank even in remote territories wherever even a GSM cell affiliation isn't conceivable.
Volume: 8
Issue: 3
Page: 705-708
Publish at: 2017-12-01

An Image Enhancement Approach to Achieve High Speed Using Adaptive Modified Bilateral Filter for Satellite Images Using FPGA

10.12928/telkomnika.v15i4.3457
Sendamarai; Nagarjuna college of engineering and technology, India Panchacharam , Giriprasad; Jawaharlal Nehru technological university, India M.N
For real time application scenarios of image processing, satellite imaginary has grown more interest by researches due to the informative nature of image. Satellite images are captured using high quality cameras. These images are captured from space using on-board cameras. Wrong ISO setting, camera vibrations or wrong sensory setting causes noise. The degraded image can cause less efficient results during visual perception which is a challenging issue for researchers. Another reason is that noise corrupts the image during acquisition, transmission, interference or dust particles on the scanner screen of image from satellite to the earth stations. If quality degraded images are used for further processing then it may result in wrong information extraction. In order to cater this issue, image filtering or denoising approach is required. Since remote sensing images are captured from space using on-board camera which requires high speed operating device which can provide better reconstruction quality by utilizing lesser power consumption. Recently various approaches have been proposed for image filtering. Key challenges with these approaches are reconstruction quality, operating speed, image quality by preserving information at edges on image. Proposed approach is named as modified bilateral filter. In this approach bilateral filter and kernel schemes are combined. In order to overcome the drawbacks, modified bilateral filtering by using FPGA to perform the parallelism process for denoising is implemented.
Volume: 15
Issue: 4
Page: 1766-1775
Publish at: 2017-12-01

Modelling and Stability Analysis of Brushless Doubly Fed Generators

10.12928/telkomnika.v15i4.6266
Abderahmane; Université of Skikda, Algeria Ganouche , Hacene; Université of Skikda, Algeria Bouzekri , Antar; Université of Skikda, Algeria Beddar
The brushless doubly-fed machine (BDFM) continues to attract increasing interest for applications in wind generation where, robustness and low servicing costs are its principles advantages. The construction aspect of the BDFM has been widely studied and currently this machine can be build with good performances. However, the control aspect remains difficult to achieve and some studies show that the BDFM is less stable than the doubly-fed induction machine. To explore the BDFM stability in all operating mode, this paper proposes a stability analysis of a grid-connected variable speed wind turbine-based BDFM. For this purpose, a linearized small signals mathematical model is proposed which takes into account both grid and control disturbances. Then, the effect of electrical parameters variation and operating speed change on the stability of the BDFM has been studied. The stability has been investigated through simulation implementation. The obtained results demonstrate the validity and the superiority of the proposed model.
Volume: 15
Issue: 4
Page: 1741-1749
Publish at: 2017-12-01

Ultra-Wideband Monostatic Antenna for behind the Wall Detection

10.11591/ijece.v7i6.pp2936-2941
Jawad Ali , Roshayati Yahya , Noorsaliza Abdullah , Syarfa Zahirah Sapuan
This article introduces an ultra-wideband (UWB) shifted arc antenna, designed using Rogers RT-5880 Duroid substrate for the human detection behind the wall. The frequency for this proposed antenna ranges from 2.8 - 15.6 GHz with the gain of around 6.05 dB. A high gain for antenna has been achieved by the implementation of defected ground structure (DGS) method to make it a suitable configuration for through wall detection applications. For the verification of through wall detection configuration, a simulation-based experiment using ground penetrating radar (GPR) technology has been conducted. The results showed that proposed single antenna can act as a monostatic transceiver in order to detect human skin behind the concrete wall. Later, the reflections received from the target have been analyzed to detect and identify the antenna, wall and target for distance calculation.
Volume: 7
Issue: 6
Page: 2936-2941
Publish at: 2017-12-01

How to Calculate the Public Psychological Pressure in the Social Networks

10.12928/telkomnika.v15i4.6832
Rui; Harbin Institute of Technology, China Jin , Hong-Li; Harbin Institute of Technology, China Zhang , Xing; Harbin Institute of Technology, China Wang , Xiao-Meng; Harbin Institute of Technology, China Wang
With the worldwide application of social networks, new mathematical approaches have been developed that quantitatively address this online trend, including the concept of social computing. The analysis of data generated by social networks has become a new field of research; social conflicts on social networks occur frequently on the internet, and data regarding social behavior on social networks must be analyzed objectively. This type of social computing method can solve a series of complex social computing problems including the calculation of public psychological pressure. The quantitative calculation of public psychological pressure is so important to the public opinion analysis that it can be widely applied in a lot of public information analysis fields.
Volume: 15
Issue: 4
Page: 1808-1816
Publish at: 2017-12-01

Improved Face Recognition Across Poses using Fusion of Probabilistic Latent Variable Models

10.12928/telkomnika.v15i4.5731
Moh Edi; Universitas Gadjah Mada, Indonesia Wibowo , Dian; Queensland University of Technology, Australia Tjondronegoro , Vinod; Queensland University of Technology, Australia Chandran , Reza; Universitas Gadjah Mada, Indonesia Pulungan , Jazi Eko; Universitas Gadjah Mada, Indonesia Istiyanto
Uncontrolled environments have often required face recognition systems to identify faces appearing in poses that are different from those of the enrolled samples. To address this problem, probabilistic latent variable models have been used to perform face recognition across poses. Although these models have demonstrated outstanding performance, it is not clear whether richer parameters always lead to performance improvement. This work investigates this issue by comparing performance of three probabilistic latent variable models, namely PLDA, TFA, and TPLDA, as well as the fusion of these classifiers on collections of video data. Experiments on the VidTIMIT+UMIST and the FERET datasets have shown that fusion of multiple classifiers improves face recognition across poses, given that the individual classifiers have similar performance. This proves that different probabilistic latent variable models learn statistical properties of the data that are complementary (not redundant). Furthermore, fusion across multiple images has also been shown to produce better perfomance than recogition using single still image.
Volume: 15
Issue: 4
Page: 1971-1981
Publish at: 2017-12-01

Contradictory of the Laplacian Smoothing Transform and Linear Discriminant Analysis Modeling to Extract the Face Image Features

10.12928/telkomnika.v15i4.6576
Arif; University of Trunojoyo, Indonesia Muntasa , Indah Agustien; University of Trunojoyo, Indonesia Siradjuddin
Laplacian smoothing transform uses the negative diagonal element to generate the new space. The negative diagonal elements will deliver the negative new spaces. The negative new spaces will cause decreasing of the dominant characteristics. Laplacian smoothing transform usually singular matrix, such that the matrix cannot be solved to obtain the ordered-eigenvalues and corresponding eigenvectors. In this research, we propose a modeling to generate the positive diagonal elements to obtain the positive new spaces. The secondly, we propose approach to overcome singularity matrix to found eigenvalues and eigenvectors. Firstly, the method is started to calculate contradictory of the laplacian smoothing matrix. Secondly, we calculate the new space modeling on the contradictory of the laplacian smoothing. Moreover, we calculate eigenvectors of the discriminant analysis. Fourth, we calculate the new space modeling on the discriminant analysis, select and merge features. The proposed method has been tested by using four databases, i.e. ORL, YALE, UoB, and local database (CAI-UTM). Overall, the results indicate that the proposed method can overcome two problems and deliver higher accuracy than similar methods. 
Volume: 15
Issue: 4
Page: 1794-1807
Publish at: 2017-12-01

Robust Video Watermarking Scheme Based on Intra-Coding Process in MPEG-2 Style

10.11591/ijece.v7i6.pp3332-3343
Rakesh Ahuja , S. S. Bedi
The proposed scheme implemented a semi blind digital watermarking method for video exploiting MPEG-2 standard. The watermark is inserted into selected high frequency coefficients of plain types of discrete cosine transform blocks instead of edge and texture blocks during intra coding process. The selection is essential because the error in such type of blocks is less sensitive to human eyes as compared to other categories of blocks. Therefore, the perceptibility of watermarked video does not degraded sharply. Visual quality is also maintained as motion vectors used for generating the motion compensated images are untouched during the entire watermarking process. Experimental results revealed that the scheme is not only robust to re-compression attack, spatial synchronization attacks like cropping, rotation but also strong to temporal synchronization attacks like frame inserting, deleting, swapping and averaging. The superiority of the anticipated method is obtaining the best sturdiness results contrast to the recently delivered schemes.
Volume: 7
Issue: 6
Page: 3332-3343
Publish at: 2017-12-01

Assessing Effectiveness of Research for Load Shedding in Power System

10.11591/ijece.v7i6.pp3235-3245
Raghu C.N. , A. Manjunatha
The research on loadshedding issues dates back to 1972 and till date many studies were introduced by the research community to address the issues. A closer review of existing techniques shows that still the effectiveness of loadshedding schemes are not yet benchmarked and majority of the existing system just considers the techniques to be quite symptomatic to either frequency or voltage. With an evolution of smart grids, majority of the controlling features of power system and networks are governed by a computational model. However, till date not enough evidences of potential computational model has been seen that claims to have better balance between the load shedding schemes and quality of power system performance. Hence, we review some significant literatures and highlights the research gap with the existing technqiues of load balancing that is meant for assisting the researcher to conclude after the selection process of existing system as a reference for future direction of study.
Volume: 7
Issue: 6
Page: 3235-3245
Publish at: 2017-12-01

Quality of Experience (QOE) Aware Video Attributes Determination for Mobile Streaming Using Hybrid Profiling

10.11591/ijeecs.v8.i3.pp597-609
Muhamad Hanif Jofri , Mohd Farhan Md Fudzee , Mohd Norasri Ismail , SHAHREEN KASIM , Jemal Abawajy
Today, consumers use a smartphone device to display the media contents for work and entertainment purposes, as well as watching online video. Online video streaming is the main cause that consume smartphone’s energy quickly. To overcome this problem, smartphone’s energy management is crucial. Thus, a hybrid energy-aware profiler is proposed. Basically, a profiler will monitor and manage the energy consumption in the smartphone devices. The hybrid energy-aware profiler will set up a protocol preference of both the user and the device. Then, it will estimates the energy consumption in smartphone. However, saving energy alone can contribute to the Quality of Experience (QoE) neglection, thus the proposed solution takes into account the client QoE. Even though there are several existing energy-aware profilers that have been developed to manage energy use in smartphones however, most energy-aware profilers does not consider QoE at the same time. The proposed solution consider both, the performance of the hybrid energy-aware profiler is compared with the baseline energy models against a variation of content adaptation according to the pre-defined variables. Three types of variables were determined; resolution, frame rate and energy consumption in smartphone devices. In this area, QoE subjective methods based on MOS (Mean Opinion Score) are the most commonly used approaches for defining and quantifying real video quality. Nevertheless, although these approaches have been established to consistently quantify users’ amounts of approval, they do not adequately realize which are the criteria of video attribute that important. In this paper, we conducted an experiment with a certain devices to measures user’s QoE and energy usage of video attribute in smartphone devices. Our results demonstrate that the list of possible solution is a relevant and useful video attribute that satify the users.
Volume: 8
Issue: 3
Page: 597-609
Publish at: 2017-12-01
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