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

28,812 Article Results

A Novel Space-time Discontinuous Galerkin Method for Solving of One-dimensional Electromagnetic Wave Propagations

10.12928/telkomnika.v15i3.5080
Pranowo; Teknik Informatika Universitas Atma Jaya Yogyakarta Pranowo
In this paper we propose a high-order space-time discontinuous Galerkin (STDG) method for solving of one-dimensional electromagnetic wave propagations in homogeneous medium. The STDG method uses finite element Discontinuous Galerkin discretizations in spatial and temporal domain simultaneously with high order piecewise Jacobi polynomial as the basis functions. The algebraic equations are solved using Block Gauss-Seidel iteratively in each time step. The STDG method is unconditionally stable, so the CFL number can be chosen arbitrarily. Numerical examples show that the proposed STDG method is of exponentially accuracy in time.
Volume: 15
Issue: 3
Page: 1310-1316
Publish at: 2017-09-01

Planar Microwave Sensors for Accurate Measurement of Material Characterization: A Review

10.12928/telkomnika.v15i3.6684
Norhanani; Universiti Teknikal Malaysia Melaka Abd Rahman , Zahriladha; Universiti Teknikal Malaysia Melaka Zakaria , Rosemizi; University Malaysia Perlis Abd Rahim , Yosza; Universiti Teknikal Malaysia Melaka Dasril , Amyrul Azuan; Universiti Teknikal Malaysia Melaka Mohd Bahar
Microwave sensor is used in various industrial applications and requires highly accurate measurements for material properties. Conventionally, cavity waveguide perturbation, free-space transmission, open-ended coaxial probe, and planar transmission line technique have been used for characterizing materials. However, these planar transmission lines are often large and expensive to build, further restricting their use in many important applications. Thus, this technique is cost effective, easy to manufacture and due to its compact size, it has the potential to produce sensitivity and a high Q-factor for various materials. This paper reviews the common characteristics of planar transmission line and discusses numerous studies about several designs of the microstrip resonator to improve the sensor performance in terms of the sensitivity and accuracy. This technique enables its use for several industrial applications such as agriculture and quality control. It is believed that previous studies would lead to a promising solution of characterizing materials with high sensitivity, particularly in determining a high Q-factor resonator sensor.
Volume: 15
Issue: 3
Page: 1108-1118
Publish at: 2017-09-01

Design of Circular Patch with Double C-Shaped Slot Microstrip Antenna for LTE 1800 MHz

10.12928/telkomnika.v15i3.5492
Yusnita; Universitas Riau Rahayu , Jherino Permana; Universitas Riau Putra
The design of a circular patch microstrip antenna with double C-shaped for LTE 1800 MHz is presented. The antenna is designed using FR-4 with dielectric constant of ε = 4.3, with thickness of substrate that is 1.6 mm and the thickness of patch and ground are 0.025 mm, Respectively the simulation results presented that the antenna works at frequency of 1714-1889.6 MHz, and work very well at frequency of 1800 MHz with a Return loss -20.484 dB, bandwidth 175.6 MHz. Technique used for broaden the bandwidth by using double C-shaped slot. In this paper presents S-Parameters, and Gain of microstrip antenna circular patch with double C-shaped slot.
Volume: 15
Issue: 3
Page: 1079-1082
Publish at: 2017-09-01

Numerical Simulation of Highly-Nonlinear Dispersion-Shifted Fiber Optical Parametric Gain Spectrum with Fiber Loss and Higher-Order Dispersion Coefficients

10.12928/telkomnika.v15i3.7215
K.; Universiti Tun Hussein Onn Malaysia G. Tay , N.; Universiti Tun Hussein Onn Malaysia Othman , N.; Universiti Tun Hussein Onn Malaysia S. M. Shah , N.; Universiti Tun Hussein Onn Malaysia A. Cholan
The previous study investigated the fiber parameters on the analytical one-pump fiber optical parametric amplifier (FOPA) gain spectrum of a loss-free highly-nonlinear dispersion-shifted fiber (HNL-DSF) and got the optimum results for each parameter. However, the FOPA gain of the combination of all the optimum values of the considered parameters was not reported. Hence, this paper intends to investigate the analytical FOPA gain of the combination of all the optimum values of the considered parameters from the previousstudy. Later, the analytical gain was compared with the numerical gain from the fourth-order Runge-Kutta (RK4) method and Matlab built-in function, ode45. Next, the effect of fiber loss and higher order dispersioncoefficients such as fourth and sixth-order dispersion coefficients were studied. It is found that RK4 gives a smaller error and the gain reduces while the bandwidth remains same in presence of fiber loss. Thefourth-order dispersion coefficient broadens the bandwidth a bit while maintaining the gain and there are two narrow-band gains generated to the left and right-side of the broad-band gain. The sixth-order dispersioncoefficient just shifts the two narrow-band gains toward or away from the broadband gain depending on the positive or negative signs of the sixth-order dispersion coefficient.
Volume: 15
Issue: 3
Page: 1461-1469
Publish at: 2017-09-01

Analysis of Memory Effects in Digital Filters with Overflow Arithmetic

10.11591/ijeecs.v7.i3.pp755-760
Mani Kant Kumar , Haranath Kar
This paper deals with the problem of undesired memory effects in nonlinear digitalfilters owing to the influence of past excitations on future outputs. The nonlinearities under consideration cover the usual types of overflow arithmetic employed in practice. Based on the Hankel norm performance, a new criterion is proposed to ensure the reduction of undesired memory effects in digital filters with overflow arithmetic. In absence of external input, the nonexistence of overflow oscillations is also confirmed by the proposed criterion. A numerical example together with simulation result showing the effectiveness of the criterion is given.
Volume: 7
Issue: 3
Page: 755-760
Publish at: 2017-09-01

Decision Support System for Bat Identification using Random Forest and C5.0

10.12928/telkomnika.v15i3.3638
Deden Sumirat; Bogor Agricultural University ; Research Center for Biology-LIPI Hidayat , Imas Sukaesih; Bogor Agricultural University Sitanggang , Gono; Research Center for Biology-LIPI Semiadi
Morphometric and morphological bat identification are a conventional method of identification and requires precision, significant experience, and encyclopedic knowledge. Morphological features of a species may sometimes similar to that of another species and this causes several problems for the beginners working with bat taxonomy. The purpose of the study was to implement and conduct the random forest and C5.0 algorithm analysis in order to decide characteristics and carry out identification of bat species. It also aims at developing supporting decision-making system based on the model to find out the characteristics and identification of the bat species. The study showed that C5.0 algorithm prevailed and was selected with the mean score of accuracy of 98.98%, while the mean score of accuracy for the random forest was 97.26%. As many 50 rules were implemented in the DSS to identify common and rare bat species with morphometric and morphological attributes.
Volume: 15
Issue: 3
Page: 1215-1222
Publish at: 2017-09-01

Weighted Least Squared Approach to Fault Detection and Isolation for GPS Integrity Monitoring

10.12928/telkomnika.v15i3.5800
Ershen; Shenyang Aerospace University Wang , Fuxia; Shenyang Aerospace University Yang , Pingping; Shenyang Aerospace University Qu , Tao; Shenyang Aerospace University Pang , Xiaoyu; Shenyang Aerospace University Lan
Reliability of a global navigation satellite system is one of great importance for global navigation purposes. Therefore, an integrity monitoring system is an inseparable part of aviation navigation system. Failures or faults due to malfunctions in the systems should be detected to keep the integrity of the system intact. In order to solve the problem that least squares method detects and isolates a satellite fault for GPS integrity monitoring, in this paper, a weighted least squares algorithm is proposed for satellite fault detection and isolation. The algorithm adopts the diagonal elements of the covariance matrix of GPS measurement equation as the weighted factor. Firstly, the weighted least squares approach for satellite fault detection establishes the test statistic by the sum of the squares of the pseudo-range residuals of each satellite for GPS. Then, the detection threshold is obtained by the false alarm rate of the fault detection, probability density function and visiable satellite number.The effectiveness of the proposed approach is illustrated in a problem of GPS (Global Positioning System) autonomous integrity monitoring system. Through the real raw measured GPS data，based on least squares RAIM method and the weighted least squares RAIM approach, the performance of the two algorithms is compared. The results show that the proposed RAIM approach is superior to the least squares RAIM algorithm in the sensitivity of fault detection and fault isolation performance for GPS integrity monitoring.
Volume: 15
Issue: 3
Page: 1022-1030
Publish at: 2017-09-01

Agent Based Modeling on Dynamic Spreading Dengue Fever Epidemic

10.12928/telkomnika.v15i3.4511
Heti; Bogor Agricultural University Mulyani , Taufik; Bogor Agricultural University Djatna , Imas Sukaesih; Bogor Agricultural University Sitanggang
Agent based model (ABM) is a computational model for simulation, behavioral representation and interaction of autonomous agents. The main problem definition related to how to make a dynamic model of dengue fever with consideration of their behavioral and interaction agent. This paper aims to develop interactive behavioral agents and related simulation models for such dynamic spreading dengue fever epidemic. This model construction consists of two agents, namely a human agent as a host and mosquito as a vector, where temperature and humidity are the environmental parameters. These environmental parameters deployed data and information from National Meteorology Climatology and Geophysics agency and supported by recent community health data of Bogor region. The verification stage evaluated model performance of two periods between January to June and between July to December 2015 showed the fitness of the model. During simulation stage where 100 humans agent and 10 mosquitoes agent were observed, indicating the decreasing of mosquito by 26.3% and the number of infected human decrease to 16% from the period of January until June to July until December 2015 respectively. These evaluation results showed that the agent based model results succeeded to follow a similar trend of decreasing pattern as actual data.
Volume: 15
Issue: 3
Page: 1380-1388
Publish at: 2017-09-01

A Soft Set-based Co-occurrence for Clustering Web User Transactions

10.12928/telkomnika.v15i3.6382
Edi; Telkom University Sutoyo , Iwan Tri Riyadi; Universitas Ahmad Dahlan Yanto , Rd Rohmat; Telkom University Saedudin , Tutut; University of Malaya Herawan
Grouping web transactions into some clusters are essential to gain a better understanding the behavior of the users, which e-commerce companies widely use this grouping process. Therefore, clustering web transaction is important even though it is challenging data mining issue. The problems arise because there is uncertainty when forming clusters. Clustering web user transaction has used the rough set theory for managing uncertainty in the clustering process. However, it suffers from high computational complexity and low cluster purity. In this study, we propose a soft set-based co-occurrence for clustering web user transactions. Unlike rough set approach that uses similarity approach, the novelty of this approach uses a co-occurrence approach of soft set theory. We compare the proposed approach and rough set approaches regarding computational complexity and cluster purity. The result demonstrates better performance and is more effective so that lower computational complexity is achieved with the improvement more than 100% and cluster purity is higher as compared to two previous rough set-based approaches.
Volume: 15
Issue: 3
Page: 1344-1353
Publish at: 2017-09-01

94 GHz Millimeter Wave Conducted Speech Enhancement

10.12928/telkomnika.v15i3.5166
Sheng; Xijing University Li , Fuming; Fourth Military Medical University M. Chen , Jinyan; Xijing University Hu , Hongbo; Xijing University Li , Lijun; Xijing University Qiu , Ying; Xijing University Tian , Jianqi; Fourth Military Medical University Wang
This paper is under in-depth investigation due to suspicion of possible plagiarism on a high similarity indexThe traditional microphone speech acquisition method has several limitations, such as short acquisition distance, non-directivity, weak ability to compensate for anti-acoustic noise, and poor sensitivity. As an alternative, our lab developed a new type of speech detection system using bio-radar. This novel speech detection method may effectively compensate for the shortcomings of the traditional microphone because of the special features of bio-radar. However, the detected radar speech is also corrupted by specific electromagnetic and ambient noises. Therefore, this study proposes a minimum mean-square error (MMSE) short-time spectral amplitude estimate algorithm to enhance radar captured speech. Because the proposed approach employs an optimal spectral amplitude estimator as well as a method to minimize the mean-square error of the log-spectra in enhancing noisy speech, this algorithm significantly reduces the colored residual noise. The enhanced radar speech was evaluated by both subjective and objective quality evaluation methods. The results demonstrate that the bio-radar can successfully detect speech signal and the proposed speech enhancement algorithm can improve radar captured speech quality.
Volume: 15
Issue: 3
Page: 1072-1078
Publish at: 2017-09-01

Design and Improvement of a Compact Bandpass Filter using DGS Technique for WLAN and WiMAX Applications

10.12928/telkomnika.v15i3.6917
Ahmed; German research Foundation (DFG) Boutejdar , Mohamed; Université Sidi Mohamed ben Abdellah Amzi , Saad Dosse; Université Sidi Mohamed ben Abdellah Bennani
This paper is under in-depth investigation due to suspicion of possible plagiarism on a high similarity indexIn this article, A compact size band pass filter based on octagonal resonators is presented to give sharp response at desired frequency bands along with very low insertion loss. The proposed filter structure is composed of octagonal microstrip resonators, backed by Quasi-Yagi slots ‘Quasi-Yagi Defected Ground Structure’ (Quasi-Yagi-DGS). By controlling the electrical coupling between the octagonal–strip and the Quasi-Yagi-DGS, the bandpass filter’s stopband is optimized for better rejection. The proposed BPF has low insertion loss and compact size because of the slow-wave effect. Meanwhile, sharp rejection bands induced by the presence of two transmission zeros. The simulated center frequency and passband insertion loss are 2.4 GHz and 0.6 dB, respectively.
Volume: 15
Issue: 3
Page: 1137-1144
Publish at: 2017-09-01

A Proposed Design of Unit Cell of Metamaterial for 5G Mobile Communication

10.12928/telkomnika.v15i3.6079
Jamal Mohammed; University of Technology, Baghdad Rasool
This paper is under in-depth investigation due to suspicion of possible plagiarism on a high similarity indexIn this manuscript a design of metamaterial unit cells which are new artificial materials made of periodic arrangement much smaller than the guided wavelength, are proposed which are suitable to work for 5G mobile communication working with millimeter frequency band at 28 GHz due the high demand for the frequency spectrum for mobile networks .The structures of unit cells were simulated using High Frequency Structure Simulator HFSS software. The design starts with the metamaterial structure which is composed of double rectangular (DRR) and circular split ring resonator (DSRR). The results of simulation showed very good results such as wide operating frequency band which is 1.34 GHz with very law radiation losses the unit cell designed to overrun the radiation losses which are appear with the work of metamaterials.
Volume: 15
Issue: 3
Page: 1145-1148
Publish at: 2017-09-01

Social Media Success Model for Knowledge Sharing (Scale Development and Validation)

10.12928/telkomnika.v15i3.5569
Setiawan; STIKOM Dinamika Bangsa Assegaff , Hendri; STIKOM Dinamika Bangsa Hendri , Akwan; STIKOM Dinamika Bangsa Sunoto , Herti; STIKOM Dinamika Bangsa Yani , Desy; STIKOM Dinamika Bangsa Kisbiyanti
This study aimed to evaluate the success of social media as a means of sharing knowledge among scholars in Indonesia. By using Information System Success Model (DeLone and McLean), this study develops a research model that will be used to investigate what factors are contributing to the success of social media as tool for sharing knowledge among academics. This article would focus on the discussion of instrument development and validation process. The method for development and validation the research instrument was refers to the framework proposed by McKanzie et al. This study resulted in a validated instrument, the instrument could use by researchers who are interested in study social media success for knowledge sharing.
Volume: 15
Issue: 3
Page: 1335-1343
Publish at: 2017-09-01

Application Profiling and Mapping on NoC-based MPSoC Emulation Platform on Reconfigurable Logic

10.12928/telkomnika.v15i3.6513
Jia Wei; Universiti Teknologi Malaysia Tang , Yuan; Universiti Teknologi Malaysia Wen Hau , Nasir; Universiti Teknologi Malaysia Shaikh-Husin , Muhammad Nadzir; Universiti Teknologi Malaysia Marsono
In network-on-chip (NoC) based multi-processor system-on-chip (MPSoC) development, application profiling is one of the most crucial step during design time to search and explore optimal mapping. Conventional mapping exploration methodologies analyse application-specific graphs by estimating its runtime behaviour using analytical or simulation models. However, the former does not replicate the actual application run-time performance while the latter requires significant amount of time for exploration. To mapapplications on a specific MPSoC platform, the application behaviour on cycle-accurate emulated platform should be considered for obtaining better mapping quality. This paper proposes an application mapping methodology that utilizes a MPSoC prototyped in Field-Programmable Gate Array (FPGA). Applications are implemented on homogeneous MPSoC cores and their costs are analysed and profiled on the platform in term of execution time, intra-core communication and inter-core communication delays. These metricsare utilized in analytical evaluation of the application mapping. The proposed analytical-based mapping is demonstrated against the exhaustive brute force method. Results show that the proposed method is able to produce quality mappings compared to the ground truth solutions but in shorter evaluation time.
Volume: 15
Issue: 3
Page: 1040-1047
Publish at: 2017-09-01

Synchronization Control of Complex Dynamical Networks Based on Uncertain Coupling

10.12928/telkomnika.v15i3.4224
Qianqian; Tianjin University of Technology Jia
This paper is under in-depth investigation due to suspicion of possible plagiarism on a high similarity indexIn recent years, the study of complex networks has been a focus subject of technology fields. In this paper, we consider the adaptive control and synchronization of uncertain complex networks. By using the adaptive control techniques with the linear feedback updated law and the well-known LaSalle invariant principle on dynamical system theory, some simple yet generic criteria are derived. Furthermore, the result is applied to typical chaotic cellular neural networks (CNN). Finally, numerical simulations are presented to demonstrate the feasibility and effectiveness of the proposed techniques.
Volume: 15
Issue: 3
Page: 1164-1172
Publish at: 2017-09-01
1 2 3
...
1920 1921
Show 1458 of 1921

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