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Standalone hybrid power system using homer software optimal case sizing of ferraguig (North West of Algeria)

10.11591/ijape.v8.i3.pp287-298
B. Afif , B. Merabet , A. Benhamou , A. Chaker
Rural areas suffer from high costs of grid extensions obliging institutions to provide for other remedies for consumers, like using generators (GE) diesel often considered as economic and reliable solutions, but at the detriment of some order environment pollution and users convenience. Furthermore, the continuous decline in GEs prices based on a renewable energy (RE) and the increasing reliability of these systems have lead to a greater use of renewable energy sources for power generation in remote areas. A property which limits the use of renewable energy is related to the variability of resources. Fluctuations in load according to annual or daily periods are not necessarily correlated to the resources. In remote areas, the preferred option is the coupling between multiple sources, such as wind turbines and solar panels, this coupling is called hybrid power system. Algeria’s geographic location presents several advantages for the development and use of renewable energy, namely, solar energy and wind energy. In addition, Algeria has huge deposits of natural gas, 98% electricity comes from gas. Therefore, currently, the production of electricity from renewable energies primarily depends on their competitiveness with economic gas. Studied technological feasibility and economic viability of the hybrid system (PV/fuel) electrification project in a school located in Ferraguig succeed to reduce high costs, energy dependence, fuel supply problem, complicated/expensive maintenance, low lifetime, impossibility of 24 hours electricity production and waste oil management issues, by using renewable energy. HOMER model is used here to size a proposed system and determine an optimum configuration.
Volume: 8
Issue: 3
Page: 287-298
Publish at: 2019-12-01

Real power loss reduction by dolphin swarm algorithm

10.11591/ijaas.v8.i4.pp285-289
Kanagasabai Lenin
In this work Spinner Dolphin Swarm Algorithm (SDSA) has been applied to solve the optimal reactive power problem. Dolphins have numerous remarkable natural distinctiveness and living behavior such as echolocation, information interactions, collaboration, and partition of labor. Merging these natural distinctiveness and living behavior with swarm intelligence has been modeled to solve the reactive power problem. Proposed Spinner Dolphin Swarm Algorithm (SDSA) has been tested in standard IEEE 14,300 bus test system and simulation results show the projected algorithm reduced the real power loss extensively.
Volume: 8
Issue: 4
Page: 285-289
Publish at: 2019-12-01

A simplified hysteresis current control for cascaded converter fed switched reluctance motor

10.11591/ijece.v9i6.pp5095-5106
Anuradha Devi Tellapati , Malligunta Kiran Kumar
Simple constructional features with no windings on rotor circuit and robustness make switched reluctance motor (SRM) a most used motors in industrial applications. Peak motor voltage rating depends on the rated voltage of the power switches. In conventional asymmetrical converter driving SRM, voltage rating of the motor depends on rating of power electronic switches in converter. Demand to rise the motor rating insists to put pressure on converter switching components which results in increased switching losses. A cascaded converter topology for SRM reduces the rating of switching components as compared to conventional converters for SRM. This paper presents a cascaded converter fed SRM drive with reduced switching losses. The paper presents a simplified hysteresis current control (HCC) for cascaded converter fed SRM. Simplified HCC control method reduces switching losses as HCC is applied to only one bridge of cascaded converter. Though the performance of the SRM remains same with cascaded converter fed SRM with HCC applied to only one bridge or to two bridges and with conventional asymmetrical converter, the switching losses are reduced to a great extent when HCC applied to one bridge of cascaded converter fed SRM. Performance of SRM is illustrated with conventional asymmetrical converter fed SRM and is compared to cascaded converter while HCC applied to only one bridge and applied to two bridges of cascaded converter. Proposed work is simulated using MATLAB/SIMULINK and results are presented.
Volume: 9
Issue: 6
Page: 5095-5106
Publish at: 2019-12-01

Integrated smart door system in apartment room based on internet

10.12928/telkomnika.v17i6.12322
Muchammad; Institut Teknologi Sepuluh Nopember Husni , Henning Titi; Institut Teknologi Sepuluh Nopember Ciptaningtyas , Ridho Rahman; Institut Teknologi Sepuluh Nopember Hariadi , Irzal Ahmad; Institut Teknologi Sepuluh Nopember Sabilla , Siska; Institut Teknologi Sepuluh Nopember Arifiani
Internet of Things (IoT) is technology which provides communication between machines without human intervention. There are many applications that implement IoT technology e.g. smart power, smart home, transportation management, and smart city. This paper proposes the usage of IoT to develop electronic key that can help to improve the security in apartment. Electronic key uses Android smart phone to access and control the door. Electronic key uses Raspberry pii, motor DC, webcam, microswitch, and Arduino GSM. Raspberry is used to get command from server and instruct the Arduino GSM to open or close the door and webcam is used to take picture from the environment for documentation. This research uses three steps to verify the user who want to open or close the door i.e. using username and password, bluetooth, and QR code scanner.
Volume: 17
Issue: 6
Page: 2747-2754
Publish at: 2019-12-01

Modified RSA-based algorithm: a double secure approach

10.12928/telkomnika.v17i6.13201
Israa; Baghdad College of Economic Sciences University Al_Barazanchi , Shihab A.; Directorate of Education Shawkat , Moayed H.; University of Imam Jaafar Alsadiq Hameed , Khalid Saeed; University of Samarra Lateef Al-badri
Security algorithms like RSA are becoming increasingly important for communications to provide companies, organizations, and users around the world, secure applications who rely heavily on them in their daily work. Security algorithms use different acquaintances among companies which might belong to various countries or even cities. Such data should essentially be encrypted to make sure that there is security in transportation. Thus, the current research paper leads to the novel system of security for the safe transfer of data. This paper examines the general principles of encryption and focuses on the development of RSA and the complexity of the encryption key so that it becomes more secure in the applications used. In this project, we will work on the RSA algorithm by adding some complexity to the 3keys (3k). This addition will increase the security and complexity of the algorithm's speed while maintaining encryption and decryption time. The paper also presents an approach by means of public key encryption to enhance cryptographic security. Moreover, double security is provided by the algorithm of RSA. This novel RSA algorithm was investigated in MATLAB. Numerical results for the various parameters such as Mean Square Error (MSE), correlation and Bit Error Ratio (BER) were implemented for the encryption of the message. The experimental results demonstrated that the proposed algorithm for 3 keys has small error rate in the retrieval of the encoded text.
Volume: 17
Issue: 6
Page: 2818-2825
Publish at: 2019-12-01

A web/mobile decision support system to improve medical diagnosis using a combination of K-Mean and fuzzy logic

10.12928/telkomnika.v17i6.12715
Zainab T.; University of Baghdad Al-Ars , Abbass; University of Information Technology and Communications Baghdad Al-Bakry
This research provides a system that integrates the work of data mining and expert system for different tasks in the process of medical diagnosis, and provides detailed steps to the process of reaching a diagnosis based on the described symptoms and mapping them with existing diagnosis available on the web or on a cloud of medical knowledge based, aggregate these data in a fuzzy manner and produce a satisfactory diagnosis of the persisting problem. The mobile phone interface would make the system user-friendly and provides mobility and accessibility to the user, while posting updates and reading in details the steps that led to the decision or diagnosis that is reached by the K-mean and the fuzzy logic inference engine. The achieved results indicate a promising diagnosis performance of the system as it achieved 90% accuracy and 92.9% F-Score.
Volume: 17
Issue: 6
Page: 3145-3154
Publish at: 2019-12-01

Application of triple-layer remote phosphor configuration results in the color quality and luminous efficiency enhancement of WLEDs

10.12928/telkomnika.v17i6.13335
Thuc Minh; Nha Trang University Bui , Phan Xuan; National Key Laboratory of Digital Control and System Engineering Le , Dinh Hoang; Ton Duc Thang University Bach , Nguyen Doan; Ton Duc Thang University Quoc Anh
This study proposed the triple-layer remote phosphor (TRP) structure to enhance the color quality and the emitted luminous flux of white LEDs (WLEDs). The TRP structure consists of three different phosphor layers that are arranged as follows: the yellow YAG:Ce3+ phosphor at the bottom, the red phosphor layer CaMgSi2O6:Eu2+,Mn2+ at the top and the green Ba2Li2Si2O7:Sn2+,Mn2+ phosphor between these two ones. The aim to use the red CaMgSi2O6:Eu2+,Mn2+ phosphor is to control the red light component so that the color rendering index (CRI) could be increased. While the green Ba2Li2Si2O7:Sn2+,Mn2+ phosphor is applied to manage the green light component, leading to the rise in luminous efficacy (LE) of WLEDs. Moreover, when the concentrations of these two phosphors are raised, that of the yellow phosphor YAG:Ce3+ has to be decreased to remain the average correlated color temperatures (ACTTs) in a range from 6000 K to 8500 K. Furthermore, not only the CRI and LE but the color quality scale (CQS) is also analyzed by controlling the two green and red phosphor concentrations. The researched results show that the higher the concentration of CaMgSi2O6:Eu2+,Mn2+, the more enhancements in the CRI will be made. In contrast, when the Ba2Li2Si2O7:Sn2+,Mn2+ concentration increases, the CRI significantly decreases. Meanwhile, CQS is likely to considerably rise in a concentration range from 10% to 14% of CaMgSi2O6:Eu2+,Mn2+, regardless of the presence of Ba2Li2Si2O7:Sn2+,Mn2+ concentration. Especially, in parallel with the improvement of CRI and CQS, the LE could be also increased by more than 40% due to the decline in back-scattering lights and the green lights supplement. From these details, the results of this study are valuable references for manufacturers to achieve the goals of enhancing color quality and luminous efficiency of WLEDs.
Volume: 17
Issue: 6
Page: 2885-2894
Publish at: 2019-12-01

Modifying playfair cipher algorithm using KAJ spiral method to fit any language regardless of the number of characters

10.11591/ijece.v9i6.pp5400-5411
Ibrahim A. Sholi , Mohamad A. Mohamed
In this paper we proposed KAJ Spiral method for supporting PlayFair cipher algorithm to use languages other than English and utilize block with more than two characters at once. Original method does not support block of characters and other languages. The method uses a spiral shape with two axes (X, Y) and the letters are spread on the axis within circles depending on the language. We use Friedman method analysis (index of coincidence) as a tool to test and prove the efficiency of KAJ Spiral method, and we found that it is at least equally secure to the original PlayFair cipher. The aims of this is making cryptography just like mathematics a universal language such that people with different languages can use this algorithm for secure communication, and at the same time make the algorithm stronger and easy to use, with the ability to fit any language.
Volume: 9
Issue: 6
Page: 5400-5411
Publish at: 2019-12-01

The Rasch-rating scale model to identify learning difficulties of physics students based on self-regulation skills

10.11591/ijere.v8i4.20292
Habibi Habibi , Jumadi Jumadi , Mundilarto Mundilarto
This study applies the unidimensional Rasch Model assumptions in identifying physics learning difficulties based on students' self-regulation abilities. A total of 126 physics teacher candidates have been observed for one semester. Self-project as a learning strategy has been used. Data were collected using 20 items in rating scales and then analyzed quantitatively to get feasibility in measuring self-regulation skills. The results have shown that the profile items analyzed by the Rasch Model are feasible to measure self-regulation skills through a self-sustaining project strategy. Most physics teacher candidates have a medium ability of 51% in the process of self-regulation, high = 33%, and low = 16%. The implications of applying self-projects to the processes of self-regulation are discussed in this article.
Volume: 8
Issue: 4
Page: 659-665
Publish at: 2019-12-01

Enhancement algorithm for reverse loop technique on planar reverse loop antenna

10.12928/telkomnika.v17i6.12087
Mohamad Harris; Universiti Teknologi Malaysia Misran , Sharul Kamal; Universiti Teknologi Malaysia Abdul Rahim , Maizatul Alice Meor; Universiti Teknikal Malaysia Melaka Said , Mohd Azlishah; Universiti Teknikal Malaysia Melaka Othman
Finding a trade-off balance between wireless transfer efficiency (WTE) and distance is a key issue in wireless energy transfer (WET). This paper presents a method of reducing the radical alteration in WTE versus distance, by using a reverse loop technique on planar reverse loop antenna (PRLA). The design focuses on 13.56 MHz Near Field Communication (NFC). The first stage uses mathematical modelling, based on an analytical approach, to determine the size of the reverse loop using Matlab. The proposed model predicts the size of the reverse loop to stabilize the WTE at a closer distance. Next, full-wave electromagnetic simulations are applied, using the computer simulation technology (CST) MICROWAVE STUDIO®, to determine the WTE effect with distance changes with mismatch condition. Planar loop antennas (PLAs) are fabricated on glass-reinforced epoxy laminated sheets (FR4). A validation of the simulation result in a real test scenario, using these PLAs and PRLA, confirms a stability enhancement in WTE at closer distance using the reverse loop technique, compared to conventional designs.
Volume: 17
Issue: 6
Page: 2713-2721
Publish at: 2019-12-01

Hybrid decode-amplify and forward protocol of FD EH relaying network: outage probability analysis

10.12928/telkomnika.v17i6.12973
Van-Duc; Nguyen Tat Thanh University Phan , Duy-Hung; Ton Duc Thang University Ha , Minh; Ton Duc Thang University Tran , Tran Thanh; Ho Chi Minh City Trang , Thanh-Long; Ho Chi Minh City University Nguyen
Nowadays, many research papers focus on the WPCN problem and how to improve its efficiency. In this research, we propose and investigate Hybrid Decode-Amplify and Forward Protocol (HDAF) of the Full-Duplex (FD) Energy Harvesting (EH) Relaying Network with the Time Switching (TS) protocol. In the beginning stage, we present the HDAF mode, which can be work like a Decode-and-Amplify (DF) or Amplify-and-Forward (AF) modes based on the best of its performance in the FD EH relaying network. Furthermore, the closed-form expression of the outage probability (OT) is analyzed and derived in connection with the primary system parameters. Besides, the comparison of the system performance in the AF, DF, and HDAF is proposed and investigated. Finally, all the results are convinced by the Monte Carlo simulation for all cases.
Volume: 17
Issue: 6
Page: 2764-2771
Publish at: 2019-12-01

KawalPilpres2019: a highly secured real count voting escort architecture

10.12928/telkomnika.v17i6.13241
Onno W.; IBI Darmajaya Purbo , Gildas; XecureIT.id Deograt , Rolof; XecureIT.id Satriyanto , Abraham; XecureIT.id Ferdinand , Pamadi; XecureIT.id Gesang , Rendra; XecureIT.id Kesuma , Kalpin Erlangga; XecureIT.id Silaen
This paper reports on the highly secured information security architecture used by the KawalPilpres 2019 to escort Voting Commission (KPU) data entry. For the first time, a voting escort implements ISO 27001 compliance information security. As of 15 May 2019, 9550 volunteers reported 482,602 voting data of 336,445 voting booths, both in the country and overseas, through the micro-apps KawalPilpres2019. PeSanKita is used as a secure communication channel and to run micro-apps KawalPilpres2019. Double Ratchet Algorithm secures the channel. Different from other voting escort initiatives, KawalPilpres2019 uses (1) primarily C1 Plano photo, (2) no upload limit per voting booth, (3) no web upload, rather via PeSanKita Secured Platform. Behind the scenes, the verification process is done twice before displaying data to the publicly accessible monitoring web. The result is a robust voting escort system, difficult to hack and guarantee data integrity. Guaranteed security, availability, and data integrity are the main requirements for future eVoting systems.
Volume: 17
Issue: 6
Page: 2834-2841
Publish at: 2019-12-01

Supervised data mining approach for predicting student performance

10.11591/ijeecs.v16.i3.pp1584-1592
Wan Fairos Wan Yaacob , Syerina Azlin Md Nasir , Wan Faizah Wan Yaacob , Norafefah Mohd Sobri
Data mining approach has been successfully implemented in higher education and emerge as an interesting area in educational data mining research. The approach is intended for identification and extraction of new and potentially valuable knowledge from the data. Predictive model developed using supervised data mining approach can derive conclusion on students' academic success. The ability to predict student’s performance can be beneficial for innovation in modern educational systems. The main objective of this paper is to develop predictive models using classification algorithm to predict student’s performance at selected university in Malaysia. The prediction model developed can be used to identify the most important attributes in the data. Several predictive modelling techniques of K-Nearest Neighbor, Naïve Bayes, Decision Tree and Logistic Regression Model models were used to predict student’s performance whether excellent or non-excellent.  Based on accuracy measure, precision, recall and ROC curve, results show that the Naïve Bayes outperform other classification algorithm.  The Naïve Bayes reveals that the most significant factors contributing to prediction of excellent students is when the student scores A+ and A in Multivariate Analysis; A+, A and A- in SAS Programming and A, A- and B+ in ITS 472.
Volume: 16
Issue: 3
Page: 1584-1592
Publish at: 2019-12-01

Investigating understanding the nature of science

10.11591/ijere.v8i4.20282
Veena Prachagool , Prasart Nuangchalerm
The survey method was employed for investigating understanding nature of science (NOS) between general science education and science pre-service teachers. Independent t-test and two-way ANOVA were used for testing hypothesis. Results found that both of two programs rated understanding NOS ranges disagree and highly agree levels in different items. The item ‘scientists work in their laboratory, even though social needs are not influence to scientists’, disagree for general science education but agree for science program. The post-hoc test indicated that there were not differences by mean scale of two programs. There was no interaction between group and components of NOS. The post-hoc test also indicated that not found the differences in each component among scientific worldview, scientific inquiry, and scientific enterprises. However, three components of NOS must incorporate to teacher preparation program for making community of science and literate person as well as philosophy of science education.
Volume: 8
Issue: 4
Page: 719-725
Publish at: 2019-12-01

Cognitive radio for TVWS usage

10.12928/telkomnika.v17i6.13111
Diego; Universidad Distrital Francisco José de Caldas Pineda , Cesar; Universidad Distrital Francisco José de Caldas Hernandez
Spectrum scarcity is an emerging issue in wireless communication systems due to the increasing demand of broadband services like mobile communications, wireless internet access, IoT applications, among others. The migration of analog TV to digital systems (a.k.a. digital TV switchover) has led to the release of a significant spectrum share that can be used to support said additional services. Likewise, TV white spaces emerge as spectral opportunities that can also be explored. Hence, cognitive radio (CR) presents itself as a feasible approach to efficiently use resources and exploit gaps within the spectrum. The goal of this paper is to unveil the state of the art revolving around the usage of TV white spaces, including some of the most important methods developed to exploit such spaces, upcoming opportunities, challenges for future research projects, and suggestions to improve current models.
Volume: 17
Issue: 6
Page: 2735-2746
Publish at: 2019-12-01
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