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30,411 Article Results

The Design of Capacitive Slit on Improving the Antenna Gain of Binomial Double Strip Hexacula Omnidirectional Broadband Antenna

10.12928/telkomnika.v16i5.8669
Syahrial; Syiah Kuala University Syahrial , Safwan; Politeknik Aceh Banda Aceh Safwan , Rizal; Syiah Kuala University Munadi , Roslidar; Syiah Kuala University Roslidar
The capacitive slit is a method of making the impedance value to be resistive. To achieve this goal is a challenge in addition to the slit antenna and gives impact to gain as one of the important parameters in antenna design. The antenna gain in a particular direction is defined as 4π times the ratio of radiation intensity in that direction to the power received by the transmitter antenna. In this research, the proposed capacitive slit method was tested on the hexacula omnidirectional broadband antenna operating on frequency 0.85-3 GHz and gain 4.8 dBi. The testing was conducted to obtain the gain improvement of the hexacula omnidirectional broadband antenna. The placement of the capacitive slit was implemented on double strip antenna with 4 times experiments. The best experiment result was obtained when three capacitive slits were placed on different strips. The capacitive slit was designed by analyzing the average value of input impedance before calculating the dimension of the capacitive slit that applied to the antenna. The experiment result shows that the best value of antenna gain is 7.19 dBi. The gain increment is linear to the number of capacitive slits applied to the antenna.
Volume: 16
Issue: 5
Page: 2032-2039
Publish at: 2018-10-01

Adaptive Multi-state Millimeter Wave Cell Selection Scheme for 5G communication

10.11591/ijece.v8i5.pp2967-2978
Mothana L Attiah , Azmi Awang Md Isa , Zahriladha Zakaria , Nor Fadzilah Abdullah , Mahamod Ismail , Rosdiadee Nordin
Millimeter wave bands have been introduced as one of the most promising solutions to alleviate the spectrum secrecy in the upcoming future cellular technology (5G) due the enormous amount of raw bandwidth available in these bands. However, the inherent propagation characteristics of mmWave frequencies could impose new challenges i.e. higher path loss, atmospheric absorption, and rain attenuation which in turn increase the outage probability and hence, degrading the overall system performance. Therefore, in this paper, a novel flexible scheme is proposed namely Adaptive Multi-State MmWave Cell Selection (AMSMC-S) through adopting three classes of mmWave base stations, able to operate at various mmWave carrier frequencies (73, 38 and 28 GHz). Two mmWave cellular Grid-Based cell deployment scenarios have been implemented with two inter-site-distances 200 m and 300 m, corresponding to target area of (2.1 km2) and (2.2 km2). The maximum SINR value at the user equipment (UE) is taken in to consideration to enrich the mobile user experience. Numerical results show an improvement of overall system performance, where the outage probability reduced significantly to zero while maintaining an acceptable performance of the 5G systems with approximately more than 50% of the mobile stations with more than 1Gbps data rate. 
Volume: 8
Issue: 5
Page: 2967-2978
Publish at: 2018-10-01

An Experimental Study of Weibull and Rayleigh Distribution Functions of Wind Speeds in Kosovo

10.12928/telkomnika.v16i5.10260
Bukurie; University of Pristina Hoxha , Rexhep; University of Pristina Selimaj , Sabrije; University of Pristina Osmanaj
This paper compares two commonly used functions, the Weibull and Rayleigh distribution functions, for fitting a measured wind speed probability distribution at a given location over a certain period. The monthly and annual measured wind speed data at 84 m height for the years have been statistically analyzed for the country with a large capacity - Kitka. The analysis is made in the case of the implementation of all the predicted capacity of wind turbines and by virtue of the probability of power distribution. The Weibull and Rayleigh probability distribution functions have been determined and their parameters have been identified. The average wind speed and the wind power density have been estimated using both distribution functions and compared those estimated from the measured probability distribution function. The Weibull distribution function fits the wind speed variation better than Rayleigh distribution function. The average wind speed was found to be 4.5 m/s and the average wind power density was 114.54 W/m According to results, we can conclude that such a distribution of winds in this region yields an appropriate average value of wind power.
Volume: 16
Issue: 5
Page: 2451-2457
Publish at: 2018-10-01

Hadoop Security Challenges and Its Solution Using KNOX

10.11591/ijeecs.v12.i1.pp107-116
Sirisha N , Kiran K V D , R Karthik
Big Data is a new technology and architecture. It can work on a very large volume of a variety of data with high-velocity, discovery, and/or analysis. Big Data is about the fast-growing sources of data such as web logics, Sensor networks, Social media, Internet text and documents, Internet pages, Search Index data, scientific research. Big data also formally introduces a complex range of analysis. Big data can evaluate mixed data (structured and unstructured) from multiple sources. As there are some security issues in big data which are no longer solved using the hashing techniques on large amount of data, this paper shows an idea of new approach of designing a Knox’ified Hadoop cluster.
Volume: 12
Issue: 1
Page: 107-116
Publish at: 2018-10-01

Data Communication in Internet of Things: Vision, Challenges and Future Direction

10.12928/telkomnika.v16i5.9402
Jammel; University of Kufa Iraq Mona
Ubiquitous technologies based heterogeneous networks has opened a new paradigm of technologies, which are enabled with various different objects called Internet of things (IoT). This field opens new door for innovative and advance patterns with considerable potential advantages in the shape of plethora of monitoring and infotainment applications around us. Data communication is one of the significant area of research in IoT due to its diverse network topologies, where diverse gadgets and devices have integrated and connected with each other. In order to communicate among devices and users, routing should be relible, secure and efficient. Due to diverse and hetrogenous netwok environment, the most of the existing routing solutions do not provide all quality of services requirement in the network. In this paper, we discuss the existing routing trend in IoT, vision and current challenges. This paper also elaborates the technologies and domains to drive this field for future perspectives. The paper concludes with discussion and main points for new researchers in terms of routing to understand about current situation in IoT.
Volume: 16
Issue: 5
Page: 2057-2062
Publish at: 2018-10-01

Compact Photonic Transmitter Based on Annular Ring Antenna for THz Applications

10.12928/telkomnika.v16i5.10647
Ibtissame; University of Sciences Hassan 1St University of Settat Moumane , Jamal; University of Sciences Hassan 1St University of Settat Zbitou , Ahmed; University of Sciences Hassan 1St University of Settat Errkik , Larbi El; University of Sciences Hassan 1St University of Settat Abdellaoui , Abdelali; University of Sciences Hassan 1St University of Settat Tajmouati , Mohamed; Microwave groupe ESEO Latrach
This paper presents the design of Continuous Wave Terahetz photonic transmitters based on photodector which convert the light signal to electrical signal, THz antenna, low-pass filter (LPF) and DC Probe. In the design of the CW THz photonic transmitter System, we begin with the matching input impedance and validation of THz antenna using an EM solver Momentum integrated in ADS “Advanced Design System”. Then we pass to the optimization of a low-pass filter which had the role of inductance, blocking the RF signal providing from the antenna to reach the DC probe. Finally, we associate the previous structures with a DC probe and simulate the whole circuit until validating the CW THz photonic transmitter circuit. The three structures are based on multi-layers GaAs substrate, which is the most widely used for THz circuit design. The dimensions of the whole circuit are 819.071 × 164.10 𝜇𝑚2.
Volume: 16
Issue: 5
Page: 2474-2480
Publish at: 2018-10-01

Voltage & Current Magnitude Pattern Recognization by Using Fuzzy Logic Toolbox for Fault Types Classification

10.11591/ijeecs.v12.i1.pp326-332
Lilik J. Awalin , Fatini Fatini , M. N. Abdullah , L.T. Tay , M. Fairuz Ab. Hamid , Bazilah Ismail
This research introduces the appropriate input pattern of Fuzzy Logic design for fault type classification of Single Line to Ground Fault at distribution network. The proposed design is solely using Fuzzy Logic as the research technique with input data from PSCAD simulation. PSCAD software simulate the circuit configuration for fault disturbance at the distribution network. The research technique was applied with multiples input values of voltage and current that extracted from the PSCAD simulation. This research testifies the output result by using different fault resistance values; 0.01Ω, 10Ω, 30Ω, 50Ω and 70Ω. Voltage sag and current swell of phase a, b and c that were obtained from the PSCAD simulation have been used as the input variables for Fuzzy Logic design. The acquired results that represented in average accuracy shown that voltage sag and current swell can draw a satisfying accuracy in classifying the fault type.
Volume: 12
Issue: 1
Page: 326-332
Publish at: 2018-10-01

Reliability Level List Based Iterative SISO Decoding Algorithm for Block Turbo Codes

10.12928/telkomnika.v16i5.7463
V; Amrita University Sudharsan , V; Amrita University Vijay Karthik , B; Amrita University Yamuna
An iterative Reliability Level List (RLL) based soft-input soft-output (SISO) decoding algorithm has been proposed for Block Turbo Codes (BTCs). The algorithm ingeniously adapts the RLL based decoding algorithm for the constituent block codes, which is a soft-input hard-output algorithm. The extrinsic information is calculated using the reliability of these hard-output decisions and is passed as soft-input to the iterative turbo decoding process. RLL based decoding of constituent codes estimate the optimal transmitted codeword through a directed minimal search. The proposed RLL based decoder for the constituent code replaces the Chase-2 based constituent decoder in the conventional SISO scheme. Simulation results show that the proposed algorithm has a clear advantage of performance improvement over conventional Chase-2 based SISO decoding scheme with reduced decoding latency at lower noise levels.
Volume: 16
Issue: 5
Page: 2040-2047
Publish at: 2018-10-01

A Review on ESCO’s Challenges and Project Management as a Solving Tool

10.11591/ijeecs.v12.i1.pp269-274
Waqar Tariq , Mohammad Lutfi Othman , Noor Izzri Abdul Wahab , Mansoor Ebrahim
The Energy Service Industry is now declared as a new source of growth for Malaysian Economy, many key players like MAESCO, Suruhanjaya Tenaga Energy Commission, KeTTHA and relevant ministries are working very hard on energy saving respective researches. There is a room for much more improvement in order to apply energy saving projects according to Malaysian environment .So far the application of project management principles are very rare in energy saving projects or in Malaysia termed as ESCO (Energy Service Company). This gives a way to synchronise project management techniques with respective implementations of energy saving projects focusing Malaysian infrastructure. In this article a review is conducted on new ways, techniques and procedures of project management and its synchronization with engineering needs especially electrical power conservation and saving projects. Moreover, the proposed research will also indicate the advancement or replacement of present system along with some advantages over our old system. A complete review is done on the background of ESCO its importance in energy saving also the relevancy of project manajement along with its basic princlples is discussed as to provide a solution for ESCO to comeover the chellenges in South East Asia generaly and in Malaysia specifically
Volume: 12
Issue: 1
Page: 269-274
Publish at: 2018-10-01

Optimizing Effort Parameter of COCOMO II Using Particle Swarm Optimization Method

10.12928/telkomnika.v16i5.9703
Kholed; Fatoni University Langsari , Riyanarto; Institut Teknologi Sepuluh Nopember (ITS) Sarno , Sholiq; Institut Teknologi Sepuluh Nopember Sholiq
Estimating the effort and cost of software is an important activity for software project managers. A poor estimate (overestimates or underestimates) will result in poor software project management. To handle this problem, many researchers have proposed various models for estimating software cost. Constructive Cost Model II (COCOMO II) is one of the best known and widely used models for estimating software costs. To estimate the cost of a software project, the COCOMO II model uses software size, cost drivers, scale factors as inputs. However, this model is still lacking in terms of accuracy. To improve the accuracy of COCOMO II model, this study examines the effect of the cost factor and scale factor in improving the accuracy of effort estimation. In this study, we initialized using Particle Swarm Optimization (PSO) to optimize the parameters in a model of COCOMO II. The method proposed is implemented using the Turkish Software Industry dataset which has 12 data items. The method can handle improper and uncertain inputs efficiently, as well as improves the reliability of software effort. The experiment results by MMRE were 34.1939%, indicating better high accuracy and significantly minimizing error 698.9461% and 104.876%.
Volume: 16
Issue: 5
Page: 2208-2216
Publish at: 2018-10-01

A Compact Wideband Monopole Antenna using Single Open Loop Resonator for Wireless Communication Applications

10.12928/telkomnika.v16i5.10454
Ahmed; German Research Foundation (DFG) Boutejdar , Mohammad A.; Electrical, Telecommunications and, Electronics Engineer Salamin , Mouloud; University M’Hamed Bougara of Boumerdes Challal , Sudipta; Department of Electronics and Communication Engineering Das , Soumia El; Mohammed V University in Rabat Hani , Saad S.; University Sidi Mohamed Ben Abdellah Fès Bennani , P. P; Univrsity of Kalyani Sarkar
A novel single layer, microstrip line fed compact wideband monopole antenna using open loop resonator has been designed and analyzed. The proposed antenna occupies a compact size of only 30 36.5 1.6 mm3. A partial ground plane is employed to enhance the operating bandwidth and reflection coefficient of the proposed antenna. The variations in operating bandwidth of the proposed antenna can be easily controlled by properly adjusting the position of the gap in the open loop resonator.The antenna prototype is fabricated on FR4 substrate with a dielectric constant 4.2. In this design, the antenna exhibits 10dB wide impedance bandwidth of 61% from 2.0174 to 3.7903 GHz.The antenna can be easily fed using a 50 Ω microstrip feed line and it covers the bandwidth requirements of a number of modern wireless communication systems such as IEEE 502.11b WLAN band (2.4 2.5 GHz), extended UMTS (2.5 2.69 GHz), IMT (2.7 2.9 GHz), and IEEE 802.16 Wi MAX band (3.3 3.6 GHz) applications. The desired antenna is designed and simulated using Computer Simulation Technology (CST). An extensive analysis of the antenna parameters (reflection coefficient, radiation pattern, directivity, and VSWR) including surface current distributions is presented and discussed in this paper. Good agreement between simulated and measured result is obtained.
Volume: 16
Issue: 5
Page: 2023-2031
Publish at: 2018-10-01

Feature Extraction Analysis for Hidden Markov Models in Sundanese Speech Recognition

10.12928/telkomnika.v16i5.7927
Intan Nurma; Padjadjaran University Yulita , Akik; Padjadjaran University Hidayat , Atje Setiawan; Padjadjaran University Abdullah , Rolly Maulana; Politeknik Pos Indonesia Awangga
Sundanese language is one of the popular languages in Indonesia. Thus, research in Sundanese language becomes essential to be made. It is the reason this study was being made. The vital parts to get the high accuracy of recognition are feature extraction and classifier. The important goal of this study was to analyze the first one. Three types of feature extraction tested were Linear Predictive Coding (LPC), Mel Frequency Cepstral Coefficients (MFCC), and Human Factor Cepstral Coefficients (HFCC). The results of the three feature extraction became the input of the classifier. The study applied Hidden Markov Models as its classifier. However, before the classification was done, we need to do the quantization. In this study, it was based on clustering. Each result was compared against the number of clusters and hidden states used. The dataset came from four people who spoke digits from zero to nine as much as 60 times to do this experiments. Finally, it showed that all feature extraction produced the same performance for the corpus used.
Volume: 16
Issue: 5
Page: 2191-2198
Publish at: 2018-10-01

Increasing the Detail and Realism in Web3D Distributed World

10.12928/telkomnika.v16i5.10113
Mursid Wahyu; Universitas Ahmad Dahlan Hananto , Ahmad; Universitas Gadjah Mada Ashari , Khabib; Universitas Gadjah Mada Mustofa , Agus; Universitas Gadjah Mada Harjoko
A complex and detailed Web3D world which represented the physical form of an institution is very difficult to be built. To simplify the work, raster images taken from the real structure were heavily utilized. However, this method has resulted in Web3D sites which were low on detail and having minimum level of realism. To overcome this deficiency, it is proposed to maximize the use of polygons. Experiment was done by re-developing the sample world with minimum use of raster images and applying polygons to 92% parts of the site. Site elements were also distributed to three servers to cope with bottleneck problem often occured when using only one server. The result was evaluated in a series of tests to see its viewing capabilities when displayed inside the web browser against various conditions, and it also evaluated in an acceptance test carried out by site users. The majority of testers felt immensely familiar with the details shown by the model as they were able to grab a more close-to-realistic experience like a real-world walk around inside the actual building complex. Problems that often occur whe using only one server ca also be reduced by using distributed world method.
Volume: 16
Issue: 5
Page: 2165-2178
Publish at: 2018-10-01

Hybrid Time-Power Switching Protocol of Energy Harvesting Bidirectional Relaying Network: Throughput and Ergodic Capacity Analysis

10.12928/telkomnika.v16i5.9118
Tran Hoang Quang; Ton Duc Thang University Minh
In this paper, we investigate system performance in term of throughput and ergodic capacity of the hybrid time-power switching protocol of energy harvesting bidirectional relaying network. In the first stage, the analytical expression of the system throughput and ergodic capacity of the model system is proposed and derived. In this analysis, both delay-limited and delay-tolerant transmission modes are presented and considered. After that, the effect of various system parameters on the proposed system is investigated and demonstrated by Monte-Carlo simulation. Finally, the results show that the analytical mathematical and simulated results match for all possible parameter values for both schemes.
Volume: 16
Issue: 5
Page: 1947-1956
Publish at: 2018-10-01

Exact Outage Performance Analysis of Amplify-and-forward-aware Cooperative NOMA

10.12928/telkomnika.v16i5.9823
Dinh-Thuan; Ton Duc Thang University Do , Tu-Trinh T.; Industrial University of Ho Chi Minh City Nguyen
In this paper, new radio access scheme that combines Amplify-and-Forward (AF) relaying protocol and non-orthogonal multiple access (NOMA) system is introduced. In particular, different scenarios for fixed power allocation scheme is investigated. In addition, the outage probability of both weak and strong user is derived and provided in closed-form expressions. Such outage is investigated in high SNR scenario and comparison performance between these NOMA scenarios is introduced. Numerical simulations are offered to clarify the outage performance of the considered scheme if varying several parameters in the existing schemes to verify the derived formulas.
Volume: 16
Issue: 5
Page: 1966-1973
Publish at: 2018-10-01
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