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30,547 Article Results

Comparison between Trigonometric, and traditional DDS, in 90 nm technology

10.12928/telkomnika.v16i5.9832
Cardarilli Gian; University of Rome Tor Vergata Carlo , Di Nunzio; University of Rome Tor Vergata Luca , Fazzolari; University of Rome Tor Vergata Rocco , Giardino; University of Rome Tor Vergata Daniele , Matta; University of Rome Tor Vergata Marco , Nannarelli; Technical University Alberto , Re; University of Rome Tor Vergata Marco , Silvestri; University of Rome Tor Vergata Francesca , Spanò; University of Rome Tor Vergata Sergio
The Direct Digital frequency Synthesizer (DDS) is an architecture largely used for the generation of numeric sine and/or cosine waveforms in different applications. In this work, authors compare two different DDS architectures: the traditional architecture, based on the exploitation of quarter wave symmetry, and the Symon’s DDS (trigonometric DDS) presented in 2002. The two layout configurations have been implemented in 90 nm technology and compared in terms of area, speed and power consumption. Comparisons have been performed in terms of circuital complexity on architectures having the same Spurious Free Dynamic Range (SFDR) and phase resolution. Experiments show that the trigonometric architecture is very efficient in terms of area.
Volume: 16
Issue: 5
Page: 2245-2253
Publish at: 2018-10-01

Improved p-q Harmonic Detection Method for Hybrid Active Power Filter

10.11591/ijece.v8i5.pp2910-2919
Chau Minh Thuyen
The accuratedetermination of the load harmonic current is one of the important factors, it decides to effect of harmonic filtering and reactive power compensation for Hybrid Active Power Filter. The p-q harmonic detection method has been widely used in determining the harmonic currents of Hybrid Active Power Filter. However, when using this method, the dynamic response of Hybrid Active Power Filter in the transient period will have a large transient time and overshoot whenever the load changes abruptly. Therefore, in this paper an improved p-q harmonic current detection method based on fuzzy logic is proposed, which aims to reduce the overshoot and transient time in transient duration of Hybrid Active Power Filter. In order to compare the dynamic response of conventional and improved p-q harmonic detection methods, simulation results have demonstrated that: the proposed method has a shorter response time, the magnitude of the supply current in the transient time is smaller and the overshoot of the fundamental active and reactive power components is very small. This has a practical significance that contributes to the stability of the Hybrid Active Power Filter system
Volume: 8
Issue: 5
Page: 2910-2919
Publish at: 2018-10-01

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

An Architecture for Simplified and Automated Machine Learning

10.11591/ijece.v8i5.pp2994-3002
Jittapoo Poolwan , Sucha Smanchat
learning has been adopted by businesses to analyze their vast data in order to make strategic decision. However, knowledge in machine learning and technical skill are usually required to prepare data and perform machine learning tasks. This obstacle prevents smaller businesses with no technical knowledge to utilize machine learning. In this paper, we propose an architecture for simplified and automated machine learning process currently supporting the data classification task. The architecture includes a method for characterizing datasets, which allows for simplifying and automating machine learning model and hyperparameter selection based on historical execution configurations. Users can simply upload their datasets via a web browser, and the system will determine the possible models and their hyperparameter configurations for the users to choose from. The prototype shows the feasibility of the proposed architecture. Although the accuracy is still limited by the small execution history and the cleanliness of the input datasets, the architecture can minimize user involvement in the machine learning process so that non-technical users can perform data classification through a web browser without installing any software.
Volume: 8
Issue: 5
Page: 2994-3002
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

Simplified Space Vector Pulse Width Modulation based on Switching Schemes with Reduced Switching Frequency and Harmonics for Five Level Cascaded H-Bridge Inverter

10.11591/ijece.v8i5.pp3417-3426
B. Sirisha , P. Satishkumar
This paper presents a simplified control strategy of spacevector pulse width modulation technique with a three segment switching sequence and seven segment switching sequence for high power applications of multilevel inverters. In the proposed method, the inverter switching sequences are optimized for minimization of device switching frequency and improvement of harmonic spectrum by using the three most desired switching states and one suitable redundant state for each space vector. The proposed three-segment sequence is compared with conventional seven-segment sequence for five level Cascaded H-Bridge inverter with various values of switching frequencies including very low frequency. The output spectrum of the proposed sequence design shows the reduction of device switching frequency, current and line voltage THD, thereby minimizing the filter size requirement of the inverter, employed in industrial applications, where sinusoidal output voltage is required.
Volume: 8
Issue: 5
Page: 3417-3426
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
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