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

30,033 Article Results

Effects of the Computer Mediated Communication Interaction on Vocabulary Improvement

10.12928/telkomnika.v16i5.10195
Siamak; Flinders University Mirzaei , Ashkan Farrokh; Unisa University Hayati
This study examined the effect of CMC interaction on Iranian EFL learners’ vocabulary improvement. The study was carried out on the basis of a comparative design and tried to compare CMC with face to-face interactions in the Iranian EFL learners in order to see whether the learners’ lexical knowledge improved by the CMC interaction. Participants of the study were advanced learners studying in a language institute. The Oxford placement test was used to determine the Iranian EFL learners’ proficiency level and ensure a homogeneous sample. Then, the participants were randomly assigned to one control group (face-to-face interaction) and one experimental group (CMC interaction) in order to compare the effect of CMC on the learners’ vocabulary improvement. The learners took a pre-test to select 12 target lexical items, treatment activity to perform information-gap task, and two immediate and delayed post-tests for assessing the acquisition of new lexical items. Yahoo Messenger was used to provide the chat communication. The research provided evidence that there was a significant relationship between the use of CMC interaction and face-to-face interaction with regard to improvement in the learners’ vocabulary learning. The result indicated that the learners’ vocabulary learning improved more in CMC interaction in comparison to face-to-face interaction. In addition, there was a significant difference in negotiating the meaning of new lexical items through CMC interaction in comparison to face-to-face interaction. Moreover, the results indicated that in terms of signal, the CMC interaction outperformed face-to-face group.
Volume: 16
Issue: 5
Page: 2217-2225
Publish at: 2018-10-01

Modelling of Time Efficiency in Heterogeneous and Adhoc Networks

10.11591/ijeecs.v12.i1.pp147-154
Yatendra Singh Bhandari , Yashwant Singh Chauhan , Priti Dimri
Heterogeneous Networks are bunch of homogeneous networks base stations grouped together. The term introduced in this research paper Time Efficiency (Te) gives out the information on the heterogeneous networks where most of the data flows in and out. In this paper, a model for evaluating Time Efficiency in heterogeneous network is developed. The common goals of different base stations in a heterogeneous network are towards coverage of area and capability improvement. Base stations in a homogeneous network differs in transmitted power, achievable rate of data, area covered, density of a base station, energy efficiency and time efficiency. To find out the area of most data flow in certain period, Time efficiency can be used as a major factor. 
Volume: 12
Issue: 1
Page: 147-154
Publish at: 2018-10-01

Harmonic Suppression Dual-band Dipole Antenna with Parasitic Elements and a Stub

10.12928/telkomnika.v16i5.9188
A. B.; Universiti Tun Hussein Onn Malaysia Albishti , S A; Universiti Tun Hussein Onn Malaysia Hamzah , S M; Universiti Tun Hussein Onn Malaysia Shah , K N; Universiti Tun Hussein Onn Malaysia Ramli , N; Universiti Tun Hussein Onn Malaysia Abdullah , M S; Universiti Tun Hussein Onn Malaysia Zainal , L; Universiti Tun Hussein Onn Malaysia Audah , A; Universiti Tun Hussein Onn Malaysia Ubin , F C; Universiti Tun Hussein Onn Malaysia Seman , A K; Universiti Tun Hussein Onn Malaysia Anuar , S Z; Universiti Tun Hussein Onn Malaysia Sapuan , R; Universiti Tun Hussein Onn Malaysia Atan , M; Universiti Teknologi Malaysia Esa , N N N Abd; Universiti Teknologi Malaysia Malik
A dual-band harmonic suppression dipole antenna suitable for energy harvesting system is presented in this paper. A linear dipole with two parasitic elements is designed and fabricated with a capability to eliminate the harmonic of higher order modes. At first, the antenna resonates at 900 MHz and 2.7 GHz. Therefore, a parasitic element is added into each of the dipole’s arm to tune the second frequency band to 2.4 GHz to fit into wireless application. However, the presence of two parasitic elements has generated an unwanted harmonic at 4.0 GHz. Thus, a stub has been integrated into the antenna’s terminal (feed line) to suppress the 4.0 GHz frequency. This technique is suitable for developing a multiband antenna with harmonic suppression. The antenna is fabricated on a FR-4 board with the size of 72×152 mm2 which operates efficiently at 0.8 GHz and 2.4 GHz which is suitable for wireless communication applications. The prototype can suppress the undesired harmful harmonics present within the frequency range of 3 to 5 GHz. The antenna has a good potential to be used in a rectenna system with a dual-band frequency operation but with better performance. Simulation and measurement results obtained are in a good agreement, which have confirmed the proposed design concept.
Volume: 16
Issue: 5
Page: 1918-1922
Publish at: 2018-10-01

An Event-based Middleware for Syntactical Interoperability in Internet of Things

10.11591/ijece.v8i5.pp3784-3792
Eko Sakti Pramukantoro , Husnul Anwari
Internet of Things (IoT) connecting sensors or devices that record physical observations of the environment and a variety of applications or other Internet services. Along with the increasing number and diversity of devices connected, there arises a problem called interoperability. One type of interoperability is syntactical interoperability, where the IoT should be able to connect all devices through various data protocols. Based on this problem, we proposed a middleware that capable of supporting interoperability by providing a multi-protocol gateway between COAP, MQTT, and WebSocket. This middleware is developed using event-based architecture by implementing publish-subscribe pattern. We also developed a system to test the performance of middleware in terms of success rate and delay delivery of data. The system consists of temperature and humidity sensors using COAP and MQTT as a publisher and web application using WebSocket as a subscriber. The results for data transmission, either from sensors or MQTT COAP has a success rate above 90%, the average delay delivery of data from sensors COAP and MQTT below 1 second, for packet loss rate varied between 0% - 25%. The interoperability testing has been done using Interoperability assessment methodology and found out that ours is qualified.
Volume: 8
Issue: 5
Page: 3784-3792
Publish at: 2018-10-01

Optimum Image Filters for Various Types of Noise

10.12928/telkomnika.v16i5.10508
Zayed M.; Al-Ahliyya Amman University Ramadan
In this paper, the quality performance of several filters in restoration of images corrupted with various types of noise has been examined extensively. In particular, Wiener filter, Gaussian filter, median filter and averaging (mean) filter have been used to reduce Gaussian noise, speckle noise, salt and pepper noise and Poisson noise. Many images have been tested, two of which are shown in this paper. Several percentages of noise corrupting the images have been examined in the simulations. The size of the sliding window is the same in the four filters used, namely 5x5 for all the indicated noise percentages. For image quality measurement, two performance measuring indices are used: peak signal-to-noise ratio (PSNR) and structural similarity (SSIM). The simulation results show that the performance of some specific filters in reducing some types of noise are much better than others. It has been illustrated that median filter is more appropriate for eliminating salt and pepper noise. Averaging filter still works well for such type of noise, but of less performance quality than the median filter. Gaussian and Wiener filters outperform other filters in restoring mages corrupted with Poisson and speckle noise.
Volume: 16
Issue: 5
Page: 2458-2464
Publish at: 2018-10-01

An Electromagnetism-like Mechanism Algorithm Approach for Photovoltaic System Optimization

10.11591/ijeecs.v12.i1.pp333-340
Jian Ding Tan , Siaw Paw Koh , Sieh Kiong Tiong , Kharudin Ali , Ying Ying Koay
Solar energy has become one of the most studied topic in the field of renewable energy. In this paper, an artificial intelligent approach is proposed for the optimization of a photovoltaic solar energy harvesting system. An Electromagnetism-Like Mechanism Algorithm (EM) has been developed to search for the hourly optimum tilt angles for photovoltaic panels. In order to investigate the effect of the search step size on the efficiency and overall accuracy of the algorithm, the EM has also been modified into several variants with different search step size settings. Experimental findings show that EM with bigger search lengths has the advantage of reaching a near optimum tilt angle in earlier iterations but less accurate. EM with smaller step lengths, on the other hand, can hit a relatively more optimum tilt angle in the process. During the peak of the power generation at noon, EM with smaller search stes found an optimum tilt angle which yielded additional 3.17W of power compared to a fixed panel. We thus conclude that the proposed EM performs well in optimizing the tilt angle of a photovoltaic solar energy harvesting system.
Volume: 12
Issue: 1
Page: 333-340
Publish at: 2018-10-01

Techno-economic Analysis of Solar-powered Lighting of Bali above Seawater Toll-Road

10.12928/telkomnika.v16i5.7056
NM; Udayana University Karmiathi , INS; Udayana University Bali Kumara , WG; Udayana University Ariastina , IW; PT. Indosat, Tbk Gunarta
The objective of this studywas to obtain atechnical and economic analysis of solar-powered lighting (SPL) implementation at Bali above Seawater Toll-Road. The SPL was designed to operate 12Hours/day with average illumination ≥15-lux. Those requirements can be met byan SPL unit that consists of 2-pieces 87-W LED lights mounted on 10-m double arms pole with 2.37-m arm length and 15º tilt angle. Each LED light was powered by a 260-Wp solar panel, 24V-180AH battery and 10-A solar charge controller. Every SPL unit should be installed on the toll-road median with 22.5-m pole-spacing and required 361-units to illuminate throughout 8,122.5-m toll-road length. Benefits of SPL implementation wereelectricity saving 256.15MWh/yr and carbon emission reduction 217.98TonesCO2/yr. However, the SPL electrical-based costwas 3.9 times more expensive than conventionalstreet lighting. And based onthe investment feasibility analysis using NPI and PI techniques showed that the SPL implementation was not feasible.
Volume: 16
Issue: 5
Page: 2342-2354
Publish at: 2018-10-01

Randomize IPv6 Stateless Address Autoconfiguration in None-stable Storage Arduino Devices

10.11591/ijeecs.v12.i1.pp254-260
Zolidah Kasiran , Rizaki Napi
The pervasiveness of IoT device requires each device to have a unique address number in order to communicate. Internet Standard specified in RFC4941-Privacy Extension for SLAAC had question raised on the randomness of the IPv6 address generated due to the shortcoming of device random generator algorithm. Improvements to the RFC’s have been proposed and Arduino Uno had been selected as IoT platform since it currently supports IPv6 implementation. An enhancement algorithm was developed. The generated IPv6 address is then tested against ENT Random Test tool for observation and conclusion.
Volume: 12
Issue: 1
Page: 254-260
Publish at: 2018-10-01

Novel Design of a Magnetically Switchable MOSFET using Magnetoresistive Elements

10.12928/telkomnika.v16i5.9539
Chinmay Vilas; SRM Institute of Science & Technology Samak , Tanmay Vilas; SRM Institute of Science & Technology Samak
Various research activities have been carried out, individually, in the fields of MOSFET design andanalysis, and magnetoresistance; however, ourresearch focused on the design and analysis of a magnetically switchable MOSFET with the application of magnetoresistive elements. Theoretical study, calculations and simulations were used in order to design and analyze the magnetically switchable MOSFET. It was observed that the magnetoresistance values of 42%, 81% and 95%, respectively, for giant magnetoresistive element, tunneling magnetoresistive element and colossal magnetoresistive element resulted in reduced resistance values of 139.2Ω, 45.6Ω and 12Ω across the MOSFET in presence of magnetic field; as compared to a higher value of 240Ω in its absence. As a consequence, the gate-source voltage increased beyond the threshold value (1.5V), and the MOSFET switched ON. Accordingly, a magnetically switchable MOSFET was designed and its behavioural characteristics were analyzed.
Volume: 16
Issue: 5
Page: 2233-2238
Publish at: 2018-10-01

Neighbor Weighted K-Nearest Neighbor for Sambat Online Classification

10.11591/ijeecs.v12.i1.pp155-160
Annisya Aprilia Prasanti , M. Ali Fauzi , Muhammad Tanzil Furqon
Sambat Online is one of the implementation of E-Government for complaints management provided by Malang City Government.  All of the complaints will be classified into its intended department. In this study, automatic complaint classification system using Neighbor Weighted K-Nearest Neighbor (NW-KNN) is poposed because Sambat Online has imbalanced data. The system developed consists of three main stages including preprocessing, N-Gram feature extraction, and classification using NW-KNN. Based on the experiment results, it can be concluded that the NW-KNN algorithm is able to classify the imbalanced data well with the most optimal k-neighbor value is 3 and unigram as the best features by 77.85% precision, 74.18% recall, and 75.25% f-measure value. Compared to the conventional KNN, NW-KNN algorithm also proved to be better for imbalanced data problems with very slightly differences.
Volume: 12
Issue: 1
Page: 155-160
Publish at: 2018-10-01

Balancing Compression and Encryption of Satellite Imagery

10.11591/ijece.v8i5.pp3568-3586
Ali J. Abboud , Ali N. Albu-Rghaif , Abbood Kirebut Jassim
With the rapid developments in the remote sensing technologies and services, there is a necessity for combined compression and encryption of satellite imagery. The onboard satellite compression is used to minimize storage and communication bandwidth requirements of high data rate satellite applications. While encryption is employed to secure these resources and prevent illegal use of image sensitive information. In this paper, we propose an approach to address these challenges which raised in the highly dynamic satellite based networked environment. This approach combined compression algorithms (Huffman and SPIHT) and encryptions algorithms (RC4, blowfish and AES) into three complementary modes: (1) secure lossless compression, (2) secure lossy compression and (3) secure hybrid compression. The extensive experiments on the 126 satellite images dataset showed that our approach outperforms traditional and state of art approaches by saving approximately (53%) of computational resources. In addition, the interesting feature of this approach is these three options that mimic reality by imposing every time a different approach to deal with the problem of limited computing and communication resources.
Volume: 8
Issue: 5
Page: 3568-3586
Publish at: 2018-10-01

A Simulation of Energy Recycling Concept in Automotive Application Using Hybrid Approach

10.11591/ijeecs.v12.i1.pp412-419
Noor Azah Samsudin , Muhammad Syariff Aripin , Shamsul Kamal Ahmad Khalid , Nor Amirul Amri Nordin
This paper presents development of a simulation to demonstrate a relatively new hybrid approach in improving energy resources that is applicable in automotive industry. The existing hybrid approach in automotive industry is considerably efficient in terms of energy saving by switching between fuel and electricity for energy resources. However, both energy resources confront various challenges. While the electricity resources require recharging, the fuel resources are scarce and expensive. Therefore, in this paper we aim to propose a relatively new hybrid approach, referred to as energy recycling concept equipped with coordination algorithm. To simulate the proposed energy recycling concept, a prototype of Electrical Control Unit (ECU) car is built. Then, an algorithm that coordinates battery charging is developed and integrated with the ECU. Finally, the simulation of the proposed energy recycling concept equipped with the coordination algorithm is evaluated on the prototype of the ECU car. The results show that the proposed energy recycling concept that allows switching between two sources of energy is applicable to operate the ECU car prototype. 
Volume: 12
Issue: 1
Page: 412-419
Publish at: 2018-10-01

Detection Hand Motion on Virtual Reality Mathematics Game with Accelerometer and Flex Sensors

10.12928/telkomnika.v16i5.7594
Erdhi Widyarto; Soegijapranata Catholic University Nugroho , T. Brenda; Soegijapranata Catholic University Chandrawati
Montessori method is a learning method using props. One of the developments props is to use the game as a medium of learning. The examples Game media as learning is the use of Virtual Reality or VR Technology. By using the VR, players will be brought into the virtual world as if the player is in the real world. The weakness of the VR game is the limited interaction with the outside world. Interaction uses only buttons and joysticks. In this paper we use Flex sensor and accelerometer sensor to detect hand movements for VR mathematic game. The result is VR games are more interactive and interesting with hand motion.
Volume: 16
Issue: 5
Page: 2287-2292
Publish at: 2018-10-01

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

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
1 2 3
...
2002 2003
Show 1404 of 2003

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