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27,544 Article Results

File Encryption and Hiding Application Based on AES and Append Insertion Steganography

10.12928/telkomnika.v16i1.6409
G. C.; Gunadarma University Prasetyadi , R.; Gunadarma University Refianti , A. B.; Gunadarma University Mutiara
Steganography is a method of hiding secret message in other innocuous looking object so that its presence is not revealed. In this paper, a message, which is a computer file of any type and size, is hidden in a selected cover or carrier, which is a computer file of certain types. The steganography method used in this paper is called append insertion steganography method. This method is chosen as an attempt to remove the limitation of message format, which appears in many popular steganography methods. To scramble the meaning of the hidden message, AES-256 (Rijndael algorithm) is used to encrypt the message with a secret passphrase. A special block of bytes is used to identify and verify the original message so it can be recovered while retaining its integrity. The C# programming language and .NET Framework are chosen to implement the algorithm into a Windows application. In this paper, one cover file contains exactly one message file. In the testing, five random files are used as secret message. Their integrity is calculated using SHA-256 before hiding and after recovery. In the testing, they all retain their integrity, proven by exact hash values. Thus, the application as the implementation of proposed algorithm is proven feasible but only for personal use as some improvements still have to be implemented.
Volume: 16
Issue: 1
Page: 361-367
Publish at: 2018-02-01

Long-term Robust Tracking whith on Failure Recovery

10.12928/telkomnika.v16i1.7271
Khaled; University of Monastir Hammemi , Mohamed; University of Monastir Atri
This article aims at a new algorithm for tracking moving objects in the long term. We have tried to overcome some potential difficulties, first by a comparative study of the measuring methods of the difference and the similarity between the template and the source image. In the second part, an improvement of the best method allows us to follow the target in a robust way. This method also allows us to effectively overcome the problems of geometric deformation, partial occlusion and recovery after the target leaves the field of vision. The originality of our algorithm is based on a new model, which does not depend on a probabilistic process and does not require a data based detection in advance. Experimental results on several difficult video sequences have proven performance advantages over many recent trackers. The developed algorithm can be employed in several applications such as video surveillance, active vision or industrial visual servoing.
Volume: 16
Issue: 1
Page: 302-313
Publish at: 2018-02-01

Design of Cloud-based and IPTV Digital Signage System

10.12928/telkomnika.v16i1.6655
Algifanri; Universitas Putera Batam Maulana , Asfiyan; Universitas Bina Nusantara Asfiyan
The purpose of this research is to control, monitoring, and broadcast video, audio, text with digital signage system based on cloud and IPTV. It also provides multi content on one screen display included YouTube channel and RSS feed. Network connection transfer using internet protocol, the component of cloud-based and IPTV included with a content management system and a broadcast management system. Companies provide digital signage services are still using one of the ads in large size, this can alleviate the cost of advertising using digital signage. Therefore, the result is a designed from a display of how the content can be variatif when displayed on a digital signage as well through cloud-based and IPTV.
Volume: 16
Issue: 1
Page: 385-389
Publish at: 2018-02-01

A New Compact CPW-Fed Dual-Band Uniplanar Antenna for RFID Applications

10.12928/telkomnika.v16i1.7560
Ahmed El; Hassan 1st University Hamraoui , El Hassane; Hassan 1st University Abdelmounim , Jamal; Hassan 1st University Zbitou , Laarbi; Hassan 1st University Elabdellaoui , Hamid; Moulay Ismail University Bennis , Mohamed; Microwave Group Latrach
In this paper a new dual-band uniplanar monopole antenna fed by Coplanar Waveguide (CPW) line is proposed for Radio Frequency Identification (RFID) applications. The antenna structure includes a CPW fed line and the dual-band operation is achieved from the G-shaped folded antenna. The antenna parameters have been investigated and optimized by using CST Microwave Studio. To validate the CST Microwave Studio results before the antenna achievement, we have conducted another study by using ADS. The final circuit was achieved, measured and validated. Experimental results show that the proposed antenna with compact size of 30*45 mm2 is simple in design and compact in size. It exhibits broadband impedance matching, consistent omnidirectional radiation patterns and appropriate gain characteristics suitable for the microwave RFID applicartions.
Volume: 16
Issue: 1
Page: 102-109
Publish at: 2018-02-01

A Solution to Partial Observability in Extended Kalman Filter Mobile Robot Navigation

10.12928/telkomnika.v16i1.9025
Hamzah; Universiti Malaysia Pahang Ahmad , Nur Aqilah; Universiti Malaysia Pahang Othman , Mohd Syakirin; Universiti Malaysia Pahang Ramli
Partial observability in EKF based mobile robot navigation is investigated in this paper to find a solution that can prevent erroneous estimation. By only considering certain landmarks in an environment, the computational cost in mobile robot can be reduced but with an increase of uncertainties to the system. This is known as suboptimal condition of the system. Fuzzy Logic technique is proposed to ensure that the estimation achieved desired performance even though some of the landmarks were excluded for references. The Fuzzy Logic is applied to the measurement innovation of Kalman Filter to correct the positions of both mobile robot and any observed landmarks during observations. The simulation results shown that the proposed method is capable to secure reliable estimation results even a number of landmarks being excluded from Kalman Filter update process in both Gaussian and non-Gaussian noise conditions.
Volume: 16
Issue: 1
Page: 134-141
Publish at: 2018-02-01

A Real Time Condition Monitoring System for Gears Operating under Variable Load Conditions

10.11591/ijeecs.v9.i2.pp493-501
Abdullah Alwadie
Gears are important component of the rotational power transmission system and are largely used in variable load and speed applications. The faults on the gear generate excessive vibration which leads to breakdown of the machine. Sensor based methods could diagnose gear faults but proved to be expensive and have limited applications due to heavy cost and need of access of gear box for sensor installation.  The motor stator current analysis has been reported to overcome the drawbacks of the sensor based fault detection methods. However, motor stator current analysis has a limited capability for reliable detection of small gear fault signatures typically for low load conditions. This paper presents an alternative non-invasive approach based on instantaneous power analysis of the motor to reliably diagnose gear faults for variable load applications. The theoretical and experimental results indicates that the instantaneous power analysis offers three fault related harmonics and amplitude variations on these harmonics could give the indication of health status of the gear.  The superiority of the proposed instantaneous power analysis technique has been confirmed through experiments performed on three operating points of the motor. The comparison of the amplitude sensitivity of the motor stator current and instantaneous power at three operating points has been performed to validate the superiority of the proposed technique.
Volume: 9
Issue: 2
Page: 493-501
Publish at: 2018-02-01

Designing an Agent for Information Extraction from Persian E-shops

10.12928/telkomnika.v16i1.5943
Nasrin; Islamic Azad University Rasouli , Leila; Islamic Azad University Abedi , Sara; Islamic Azad University Ghaei
E-shops are among the most conventional applications of Electronic Commerce. In these shops, the buyers search for their goods through key words or classifications and read the product description provided by the sellers. Though, when the number of items is high, this gets to be difficult for the users. On the one hand, there are too many e-shops, and browsing in these shops to find the best and most appropriate goods is a difficult and time-consuming process. On the other hand, product descriptions are not the same in different websites, and there are different product forms. This study investigates about products and sellers in various websites based on the conditions and user requirements through software agents which present the extracted information in the form of a table to the users which enables them to compare prices and each seller’s conditions without spending too much time for browsing. Using this method increases precision and recall indices comparing to a conventional user browsing.
Volume: 16
Issue: 1
Page: 455-462
Publish at: 2018-02-01

Efficiency of 128-bit Encryption and Decryption Process in Elgamal Method Using Elliptic Curve Cryptography (ECC)

10.12928/telkomnika.v16i1.6953
Dicky; STMIK Triguna Dharma Nofriansyah , Afzalur; STMIK Triguna Dharma Syaref , Widiarti; STMIK Triguna Dharma R Maya , Ganefri; Universitas Negeri Padang Ganefri , Ridwan; Universitas Negeri Padang Ridwan
Cryptography is a growing science of data security. The integrity of a data is an important thing to keep the secrets contained in the data. In this research will be visualized the efficient quantities that use elliptic curves and do not use them. The Elgamal method is an asymmetric cryptographic algorithm whose complexity of processes. It is especially for digital signatures. This research will discuss about the use of ECC to optimize and streamline the Encryption and Decryption process in particular 128-bit Elgamal method. The hope is that by using elliptic curves the timing of the encryption and decryption process can run faster in the computation of Elgamal Method.
Volume: 16
Issue: 1
Page: 352-360
Publish at: 2018-02-01

Development and Performance Enhancement of MEMS Helix Antenna for THz Applications using 3D HFSS-based Efficient Electromagnetic Optimization

10.12928/telkomnika.v16i1.8000
Abdelhakim; University of Tlemcen Boudkhil , Mohammed; University of Tlemcen Chetloul , Nadia; University of Tlemcen Benabdellah , Nasreddine; University of Tlemcen Benahmed
Interest of Micro-Electromechanical System (MEMS) antennas in Terahertz (THz) applications has rapidly expanded in recent years due to the advent of accurate Computer Aided Design (CAD) tools. The very special needs of newly proposed MEMS antennas, especially with a wide bandwidth range, require advanced optimization procedures of enhancing already established designs. This paper provides a compact design of a wideband MEMS helix antenna optimized using tree-dimensional High Frequency Structure Simulator (3D-HFSS) based on Quasi-Newton (Q-N) and Sequential Non Linear Programming (SNLP) techniques to modify the antenna structure with a high accuracy for the selective band of frequencies by training the samples and minimizing the error from Finite Element Method- (FEM) based simulation tool. The helix antenna is presented using MEMS technology and shows high performance demonstrated by very low return losses of less than -20 to -65 dB for a wide range of frequencies from 2.5 to 5 THz. High antenna geometry precision and efficient performance are finally achieved by rectifying and synthesizing various tunable parameters embedded in silicon substrate including both helix form and feeding line parameters.
Volume: 16
Issue: 1
Page: 210-216
Publish at: 2018-02-01

OFET Preparation by Lithography and Thin Film Depositions Process

10.12928/telkomnika.v16i1.6544
Sujarwata; Universitas Negeri Semarang Sujarwata , Fianti; Universitas Negeri Semarang Fianti , Langlang; Universitas Negeri Semarang Handayani , Aji; Universitas Negeri Semarang Kampus Sekaran Gunungpati Semarang Purwinarko , Susilo; Universitas Negeri Semarang Susilo
The length of the channel OFET based thin film is determined during preparation takes place using the technique of lithography and mask during the metal deposition process. The lithography technique is the basic process steps in the manufacture of semiconductor devices. Lithography is the process of moving geometric shapes mask pattern to a thin film of material that is sensitive to light. The pattern of geometric shapes on a mask has specifications, as follows: long-distance source and drain channels varied, i.e. 100 μm, the width of the source and drain are made permanent. Bottom contact OFET structure has been created using a combination of lithography and thin film deposition processes.
Volume: 16
Issue: 1
Page: 77-83
Publish at: 2018-02-01

Low Complexity Multi-User MIMO Detection for Uplink SCMA System Using Expectation Propagation Algorithm

10.12928/telkomnika.v16i1.7365
Alva; University of Brawijaya Kosasih , Onny; University of Brawijaya Setyawati , Rahmadwati; University of Brawijaya Rahmadwati
Sparse code multiple access (SCMA), which combines the advantages of low density signature (LDS) and code-division multiple access (CDMA), is regarded as one of the promising modulation technique candidate for the next generation of wireless systems. Conventionally, the message passing algorithm (MPA) is used for data detector at the receiver side. However, the MPA-SCMA cannot be implemented in the next generation wireless systems, because of its unacceptable complexity cost. Specifically, the complexity of MPA-SCMA grows exponentially with the number of antennas. Considering the use of high dimensional systems in the next generation of wireless systems, such as massive multi-user MIMO systems, the conventional MPA-SCMA is prohibitive. In this paper, we propose a low complexity detector algorithm named the expectation propagation algorithm (EPA) for SCMA. Mainly, the EPA-SCMA solves the complexity problem of MPA-SCMA and enables the implementation of SCMA in massive MU-MIMO systems. For instance, the EPA-SCMA also enables the implemantation of SCMA in the next generation wireless systems. We further show that the EPA can achieve the optimal detection performance as the numbers of transmit and receive antennas grow. We also demonstrate that a rotation design in SCMA codebook is unnecessary, which is quite rather different from the general assumption
Volume: 16
Issue: 1
Page: 182-188
Publish at: 2018-02-01

Improving the Performance of Viterbi Decoder using Window System

10.11591/ijece.v8i1.pp611-621
Rekkal Kahina , Abdesselam Bassou
An efficient Viterbi decoder is introduced in this paper; it is called Viterbi decoder with window system. The simulation results, over Gaussian channels, are performed from rate 1/2, 1/3 and 2/3 joined to TCM encoder with memory in order of 2, 3. These results show that the proposed scheme outperforms the classical Viterbi by a gain of 1 dB. On the other hand, we propose a function called RSCPOLY2TRELLIS, for recursive systematic convolutional (RSC) encoder which creates the trellis structure of a recursive systematic convolutional encoder from the matrix “H”. Moreover, we present a comparison between the decoding algorithms of the TCM encoder like Viterbi soft and hard, and the variants of the MAP decoder known as BCJR or forward-backward algorithm which is very performant in decoding TCM, but depends on the size of the code, the memory, and the CPU requirements of the application.
Volume: 8
Issue: 1
Page: 611-621
Publish at: 2018-02-01

Optimal Expenditure and Benefit Cost Based Location, Size and Type of DGs in Microgrids Systems Using Adaptive Real Coded Genetic Algorithm

10.12928/telkomnika.v16i1.6761
Umar; Institut Teknologi Sepuluh Nopember Umar , Firdaus; Institut Teknologi Sepuluh Nopember Firdaus , Adi; Institut Teknologi Sepuluh Nopember Soeprijanto , Ontoseno; Institut Teknologi Sepuluh Nopember Penangsang
The economic issue is an essential element to determine whether DG should be installed or not. This work presents the economical approach for multi-type DGs placement in microgrid systems with more comprehensive overview from DG’s owner perspective. Adaptive Real Coded GA (ARC-GA) with replacement process is developed to determine the location, type, and rating of DGs so as the maximum profit is achieved. The objectives of this paper are maximizing benefit cost and minimizing expenditure cost. All objectives are optimized while maintaining the bus voltage at the acceptable range and the DGs penetration levels are below of the DGs capacities.The proposed method is applied on the 33 bus microgrids systems using conventional and renewable DG technology, namely Photovoltaic (PV), Wind Turbine (WT), Micro Turbine (MT) and Gas Turbine (GT). The simulation results show the effectiveness of the proposed approach.
Volume: 16
Issue: 1
Page: 10-17
Publish at: 2018-02-01

A Multiband Printed Antenna Suitable for Wireless Applications

10.12928/telkomnika.v16i1.7059
S.; University of Hassan 1st Settat El Kilani , L. El; University of Hassan 1st Settat Abdellaouib , J.; University of Hassan 1st Settat Zbitou , J.; CRMEF Terhzaz , A.; University of Hassan 1st Settat Errkik , M.; Microwave Group ESEO Angers Latrach
This study deals with a new research work on a low cost multiband printed antenna which can be used for three operating frequency bands GSM900/PCS/WIFI/Bluetooth. The achieved antenna is mounted on an FR-4 substrate. In this study, the solts technique is used to obtain the multiband behavior. The different solts are inserted in the radiator face and the back face that is the ground. The whole circuit is optimized taking into account the good matching of the input impedance in the operating frequency bands with a stable radiation pattern. In order to optimize the proposed antenna structure we have used CST-MW and to compare the obtained simulation results we have conducted another electromagnetic simulation by using HFSS solver. The final circuit validated into simulation has been fabricated and tested which permits to validate the proposed multiband antenna.
Volume: 16
Issue: 1
Page: 159-165
Publish at: 2018-02-01

Household Purposes in A Single Touch Via Bluetooth Using Smartphones

10.11591/ijeecs.v9.i2.pp351-353
Bhavani Rohit , Rengamani J
Technology emerges in our environment day by day. But, still, we lag in keep on using multiple remotes for every device in our homes. Once Bluetooth came up it changes. People started using mobile phones connected to their devices to hear songs wireless and change channels using a mobile phone. A further implementation is kept on moving with multiple remotes for their usage. So, we had an idea that all our household devices may be controlled on our mobile phones via Bluetooth which is cheaper even for urban peoples. Now, all home devices with remote are IR based which doesn't work on sunlight, fluorescent bulbs due to interference. Switch over Bluetooth control reduces remotes in a sense called plastics. Mobile applications are evolved user-friendly to all the people on the day to day lives. Merge those applications to the household devices to control all household devices operated via remote such as TV, DVD, Home theatres, AC, even Table fan etc., Instead of removing IR's just interface Bluetooth chip on those household devices to control every remote device by using your smartphone. Why I am moving to Bluetooth instead of Wi-Fi. Bluetooth is cheaper, advanced to control devices in the range of 50 meters. But IR is useful to 10 meters, and once you block the signal, it will not work.
Volume: 9
Issue: 2
Page: 351-353
Publish at: 2018-02-01
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