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31,291 Article Results

Analysis Predicted Location of Harmonic Distortion in RF Upconverter Structure

10.12928/telkomnika.v16i6.7628
Sirmayanti; The State Polytechnic of Ujung Pandang Sirmayanti , Mike; Victoria University Faulkner
A new mathematical analysis to predict the magnitude size of the distortion products from the signal up-conversion process output is presented. The signal up-conversion process converts the digital baseband from the analog baseband into a radio frequency signal. When the signal baseband involves frequency offsetting then occurring a number of distortion products which can reduce the dynamic range so it is difficult to meet the spectrum mask requirements within the operating band. This paper will focus on methods of new mathematical analysis using a continuous frequency range and only applies to a single side band tone, with constant amplitude into any value of frequency offsets. The novel contribution to the analysis starts at generating the gate signal and convolution of the gate signal into the reference carrier signal. The results show very close between the simulation results and the calculation of the predicted location of the distortions.
Volume: 16
Issue: 6
Page: 2608-2615
Publish at: 2018-12-01

Electromagnetic Characteristics Measurement of Organic Material Absorber

10.12928/telkomnika.v16i6.9687
Reza; Centre of Electronics Technology Septiawan , Sardjono; Centre of Electronics Technology Trihatmo , Juliati; Centre of Electronics Technology Junde , Dody A.; Center of Polymer Technology Winarto , Arief; Centre of Electronics Technology Rufiyanto , Erik Madyo; Centre of Electronics Technology Putro , Budi; Centre of Electronics Technology Sulistya , Arky; Centre of Electronics Technology Astasari
Electro Magnetic Compatibility (EMC) Chamber requires high performance absorber material to assure the quality of EMC chamber related to Radio Frequency (RF) shielding effectiveness of the corresponding chamber. RF shielding effectiveness is measured following EN 50147-1 testing method. EMC laboratory of BPPT (Indonesian Agency for the Assessment and Application of Technology uses polyurethane absorber material which absorbs the carbon-neoprene mixture to maintain consistent RF performance over a broad frequency band, especially in the frequency range of CISPR 22 radiated emission test between 30 MHz to 6 GHz, limits in CISPR 22 (Information technology equipment-radio disturbance characteristics-limits and methods of measurement). This paper proposes alternative absorber materials based on organic materials: rice husk, coconut husk, cotton and sawn wood crumbs. In the early phase of this research, the frequency under consideration are 900 MHz and 1800 MHz. These frequencies are mostly used by mobile phone devices, therefore at this phase the resulted organic material absorber may be used for alternative mobile phone casing before to be used as absorber material for EMC laboratory in a broader frequency band. The organic materials are produced by mixing them with cement, carbon, and resin. Free space testing method is used in the measurements. Results has shown a mixture of 50% coconut husk with resin absorb the most radiated emission in 900 MHz, while 30% of coconut husk will absorb the most radiated emission in 1800 MHz.
Volume: 16
Issue: 6
Page: 2507-2513
Publish at: 2018-12-01

An Adaptive Internal Model for Load Frequency Control Using Extreme Learning Machine

10.12928/telkomnika.v16i6.11553
Adelhard Beni; Hiroshima University Rehiara , He; Hiroshima University Chongkai , Yutaka; Hiroshima University Sasaki , Naoto; Hiroshima University Yorino , Yoshifumi; Hiroshima University Zoka
As an important part of a power system, a load frequency control has to be prepared with a better controller to ensure internal frequency stability. In this paper, an Internal Model Control (IMC) scheme for a Load Frequency Control (LFC) with an adaptive internal model is proposed. The effectiveness of the IMC control has been tested in a three area power system. Results of the simulation show that the proposed IMC with Extreme Learning Machine (ELM) based adaptive model can accurately cover the power system dynamics. Furthermore, the proposed controller can effectively reduce the frequency and mechanical power deviation under disturbances of the power system.
Volume: 16
Issue: 6
Page: 2879-2887
Publish at: 2018-12-01

Development of a Modular Unit of a Higher Level Framework or Tool for Basic Programming Course Teaching Through E-Learning Mode

10.12928/telkomnika.v16i6.10033
Radhika; VNR Vignana Jyothi Pathi , G.V.; DRS International School Rao , P. Rama; VNR Vignana Jyothi Krishna , P. Bharath; VNR Vignana Jyothi Kumar
This paper reports about the development of a modular unit of a higher level framework or tool whose intended objective is the creation of animated lessons for basic programming (CS1) course in computer science discipline with visual aids. The goal of such lessons is to address the difficulties faced by the novice programmers in CS1 course.This module here after referred to as ‘type writer’allows instructors to render programmes or code snippets in a live typing manner as opposed to their sudden or en-block placement on the presentation area like a Power Point Slide; a commonly used approach in the present day eLearning.This project is planned to be executed in two stages and ‘type writer’ is the outcome of the first stage. This would be combined with another two modules that are planned to be developed in the second stage, to make the complete tool. The entire tool would be developed in Action Script 3.0 language that works on Adobe Flash Platform.
Volume: 16
Issue: 6
Page: 2828-2834
Publish at: 2018-12-01

Detection and Separation of Eeg Artifacts Using Wavelet Transform

10.11591/ijict.v7i3.pp149-156
R. Suresh Kumar , P. Manimegalai
Bio-medical signal processing is one of the most important techniques of multichannel sensor network and it has a substantial concentration in medical application. However, the real-time and recorded signals in multisensory instruments contains different and huge amount of noise, and great work has been completed in developing most favorable structures for estimating the signal source from the noisy signal in multichannel observations. Methods have been developed to obtain the optimal linear estimation of the output signal through the Wide-Sense-Stationary (WSS) process with the help of time-invariant filters. In this process, the input signal and the noise signal are assumed to achieve the linear output signal. During the process, the non-stationary signals arise in the bio-medical signal processing in addition to it there is no effective structure to deal with them. Wavelets transform has been proved to be the efficient tool for handling the non-stationary signals, but wavelet provide any possible way to approach multichannel signal processing. Based on the basic structure of linear estimation of non-stationary multichannel data and statistical models of spatial signal coherence acquire through the wavelet transform in multichannel estimation. The above methods can be used for Electroencephalography (EEG) signal denoising through the original signal and then implement the noise reduction technique to evaluate their performance such as SNR, MSE and computation time.
Volume: 7
Issue: 3
Page: 149-156
Publish at: 2018-12-01

Design and Analysis of Broadband Elliptical Microstrip Patch Antenna for Wireless Communication

10.12928/telkomnika.v16i6.9246
Ali Khalid; Al Mustansiriyh University Jassim , Raad H.; Al Mustansiriyh University Thaher
In this paper presents the design and manufacture of a new broadband elliptical patch antenna with a microstrip feed line and optimum antenna  parameters. The antenna dimension of (30×21×1.6) mm3 and fabricated on an FR-4 epoxy substrate having relative dielectric constant ε_r=4.3, loss tangent tan (δ) =0.002 and the feed line used has characteristic impedance of 50Ω.The designed antenna has the capability of operating in the bandwidth (6.95 - 30.94) GHz and the gain (6.8) dBi. The antenna performance was modified by inserting a slots in the ground plane to achieve impedance bandwidth (when S11≤ -10dB) and slots to patch to improve the gain. The modified antenna was designed to be used for fifth generation (5G) mobile communication. The simulation results are obtained using CST software.
Volume: 16
Issue: 6
Page: 2492-2499
Publish at: 2018-12-01

Different Multilayer Substrate Approaches to Improve Array Antenna Characteristics for Radar Applications

10.12928/telkomnika.v16i6.10193
N.; National School of Applied Sciences Chater , T.; National School of Applied Sciences Mazri , M.; National School of Applied Sciences Benbrahim
The aim of this paper is to investigate deeply in multi-layer substrate technique as a way of improving the characteristics of patch array antenna for electronic scanning radar application. The basic array antenna consists of 8 patches mounted on a FR-4 substrate and operating at 3GHz frequency. The feeding technique is microstrip technology. This structure has some disadvantages as a poor gain and a narrow bandwidth. In fact, the obtained gain value does not exceed 7 dB which could be explained by the lossy nature of the FR4 substrate. On the other side, the narrow bandwidth is caused by the microstrip limitations. For this reason, the technique of multi-layer substrate is proposed in this paper. Many approaches are investigated and the distance between the layers is studied. The design and simulations of each approach are performed under the tool Advanced Design System of Keysight Company. A comparison between simulation results of all approaches including simulation results of the basic array antenna will be analyzed.
Volume: 16
Issue: 6
Page: 2588-2596
Publish at: 2018-12-01

Voltage Regulation of Boost Converter using Observer based Sliding Mode Controller

10.12928/telkomnika.v16i6.11558
Ramadhani Kurniawan; Brawijaya University Subroto , Sapriesty Nainy; Brawijaya University Sari , Zainul; Brawijaya University Abidin , Kuo Lung; National Taiwan University Lian
This study dealt with output voltage regulation of boost converter using observer based sliding mode controller comprises of adaptive PI sliding surface. Observer was designed to estimate the inductor current value, such that no sensor was required as a feedback. Adaptive PI sliding surface was constructed from the difference between estimated inductor current and its reference value. The stability of proposed method was ensured by using Lyapunov direct method. To test the system performance, numerical simulation was conducted. The result indicated that the integral absolute error value of proposed method was 0.19, which was 7 times less than sliding mode with PI sliding surface. Consequently, the proposed method was able to estimate accurately the inductor value, track the reference voltage perfectly, and show its robustness against parameter variations.
Volume: 16
Issue: 6
Page: 2896-2904
Publish at: 2018-12-01

Performance Enhancement of Wideband Reflectarray Antennas Embedded on Paper Substrate Materials

10.12928/telkomnika.v16i6.9595
M. Y.; Universiti Tun Hussein Onn Malaysia (UTHM) Ismail , H. I.; Universiti Tun Hussein Onn Malaysia (UTHM) Malik
This research presents an innovative solution to address the bandwidth limitation of microstrip reflectarray antennas. Organic substrate materials with controlled compositions have been characterized to be employed as substrate materials for microstrip reflectarrays. The three proposed materials show low dielectric permittivity values of 1.81, 1.64 and 1.84 along with loss tangents of 0.053, 0.047 and 0.057 respectively. The proposed substrate materials have been verified by modelling reflectarray unit elements in CST MWS and measured using a waveguide simulator technique. The comparison between measured and simulated results show a good agreement with promising broadband performance of 312, 340 and 207 MHz for S1, S2 and S3 substrate materials respectively.
Volume: 16
Issue: 6
Page: 2616-2621
Publish at: 2018-12-01

A State of Art on Energy Efficient Multipath Routing In Wireless Sensor Networks

10.11591/ijict.v7i3.pp111-116
Swedika Sharma
Wireless sensor network is the combination of sensor nodes where sensor nodes are distributed all over the network. There are some challenges that come into the wireless sensor network n context to energy efficiency, network lifetime, storage and battery backup. The most important feature of a routing protocol, in order to be efficient for WSNs, is the energy consumption and the extension of the network’s lifetime. In this paper, we have analyzed various routing techniques for WSN that increases the network lifetime and energy consumption.
Volume: 7
Issue: 3
Page: 111-116
Publish at: 2018-12-01

Secure Code Generation for Multi-Level Mutual Authentication

10.12928/telkomnika.v16i6.10437
Gregor Alexander; Al-Mustansiriyah University Aramice , Jaafar Qassim; Al-Mustansiriyah University Kadhim
Any secured system requires one or more logging policies to make that system safe. Static passwords alone cannot be furthermore enough for securing systems, even with strong passwords illegal intrusions occur or it suffers the risk of forgotten. Authentication using many levels (factors) might complicate the steps when intruders try to reach system resources. Any person to be authorized for logging-in a secured system must provide some predefined data or present some entities that identify his/her authority. Predefined information between the client and the system help to get more secure level of logging-in. In this paper, the user that aims to log-in to a secured system must provide a recognized RFID card with a mobile number, which is available in the secured systems database, then the secured system with a simple algorithm generates a One-Time Password that is sent via GSM Arduino compatible shield to the user announcing him/her as an authorized person.
Volume: 16
Issue: 6
Page: 2643-2650
Publish at: 2018-12-01

Secure and Efficient Bi-Directional Proxy Re-Encyrption Technique

10.11591/ijeecs.v12.i3.pp1143-1150
Chandrakala B M , S C Linga Reddy
The low cost availability of smart devices and broadband connection has led to rapid growth of communication over Internet. As of today the internet based communication service is widely used in various application services such as in E-Mail transaction of sensitive data (medical data), online money transaction etc. all these services requires a strong security. There has been continuous ongoing research by various cryptanalyst to enhance security of cryptography especially in semi-untrusted server. However, performance, computation time and ease of use play a significant role in using the algorithm for implementation. Proxy re-encryption plays a significant role in protecting data that are stored in semi-untrusted server. Many existing Proxy re-encryption technique induces high computation overhead due to adoption of public key cryptography such RSA (Rivet Shamir Adleman), ECC (Elliptical Curve Cryptography) etc. and it suffer from quantum attack. To address this lattice based cryptography is adopted by various approaches which is based on Learning With Error which shows resilience against quantum attacks such Chosen Cipher data attack and Chosen Plain Text attack. The drawback with existing lattice cryptography based approach is that they are unidirectional and adopts bilinear pairing which compromise security and induces high computation cost. To address this work present a Bidirectional Proxy Re-encryption scheme by adopting lattice based cryptography technique. Experiment is conducted for computation overhead by varying key and data size which attained significant performance improvement over existing Proxy Re-encryption scheme.
Volume: 12
Issue: 3
Page: 1143-1150
Publish at: 2018-12-01

The Readiness of Palm Oil Industry in Enterprise Resource Planning

10.12928/telkomnika.v16i6.9883
Darius; Bina Darma University Antoni , Deni; Bina Darma University Fikari , Muhamad; Bina Darma University Akbar , Ferry; Edith Cowan University Jie
The palm oil industry is one of the sources of non-oil and gas foreign exchange of Indonesia. It contributes to National Gross Domestic Product at 13.96% in 2017. This study aims to examine the readiness of palm oil industry in the implementation of Enterprise Resources Planning (ERP). The readiness of palm oil industry in implementing ERP, is not only about a large cost, but also the ERP has required great resources including human respurces, technology, management, and process and data. Thus, it should fit the needs of the industry. Using the Critical Success Factors (CSF) method, this study employs five dimensions of the ERP readiness, that is management, process, technology, data, and personnel. A survey research method is employed to acquire the data and there are 19 items for those five dimensions. A gap analysis is employed to analyse the data and this method is used to determinethe disparity between existing conditions and future expectations. The findings reveal that the palm oil industry is well prepared to implement the ERP from four dimensions of management, technology, process and personnel.The management factor is the one of an factor of readiness in the ready category together with other factors including process, and human resources. Technology is the best factor which has led to increasing demands for building a strong information technology infrastructure to integrate business processes. The company needs to complete the master data onto the database and change the database system integrated into a single database that causes data is lack of ready data in ERP implementation.
Volume: 16
Issue: 6
Page: 2692-2702
Publish at: 2018-12-01

Optimization Learning Vector Quantization Using Genetic Algorithm for Detection of Diabetics

10.11591/ijeecs.v12.i3.pp1111-1116
Inggih Permana , Nesdi Evrilyan Rozanda , Fadhilah Syafria , Febi Nur Salisah
This study proposed the method to improve the result of Learning Vector Quantization (LVQ) by optimizing the weight vectors using a genetic algorithm (GA) to detect the diabetics. Initial value of individuals for GA is taken from weight vectors which come from the last m iterations of LVQ training result. The result of experiment showed that there is a significant increase in sensitivity level, however there is a significant decrease in specificity level. It means the proposed method success in improving the LVQ ability to recognized the diabetics, but it lowers the ability of LVQ to recognize the people unaffected by diabetes.This study proposed the method to improve the result of Learning Vector Quantization (LVQ) by optimizing the weight vectors using a genetic algorithm (GA) to detect the diabetics. Initial value of individuals for GA is taken from weight vectors which come from the last m iterations of LVQ training result. The result of experiment showed that there is a significant increase in sensitivity level, however there is a significant decrease in specificity level. It means the proposed method success in improving the LVQ ability to recognized the diabetics, but it lowers the ability of LVQ to recognize the people unaffected by diabetes.
Volume: 12
Issue: 3
Page: 1111-1116
Publish at: 2018-12-01

The Application of General MOS Gas Sensors for Discriminating Formalin Content

10.12928/telkomnika.v16i6.10363
Arief; Jenderal Soedirman University Sudarmaji , Budi; Muria Kudus University Gunawan , Shoufika; Muria Kudus University Hilyana , Henry; Jenderal Soedirman University Fernando , Agus; Jenderal Soedirman University Margiwiyatno
This paper describes the application of Metal Oxide Semiconductor (MOS) gas sensors which are intrinsically designed to sense volatile compounds for measuring the vapor of formalin. We utilized 7 commercial MOS gas sensors (namely TGS-2600, TGS-2602, TGS-2620, TGS-813, MQ-137, MQ-135, and MQ-5) to sense formalin in certain concentrations and their presence in meat. We built a static headspace system to measure the vapor of formalin. The sensor chamber is 540-cm3, made from 5 mm acrylic. The output of MOS (Sensitivity ratio) is acquired into computer using an Arduino-based interface. We tested 3 concentrations of formalin (10%, 20% and 30%) and their presence in meat. We found that individually each sensor provides proportional response to formalin concentrations, and for their presence in meat as well. The Principle Component Analysis (PCA) method is used to show performance of the array MOS sensor in discriminating the formalin contents. The PCA result shows that by using two PCs (holding most 96% data), it can clearly distinguish the three formalin contents. However the array sensors just can discriminate clearly between meat containing formalin and those not. The success rate of discrimination the formalin contents in meat is 91.7%.
Volume: 16
Issue: 6
Page: 2905-2912
Publish at: 2018-12-01
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