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30,547 Article Results

Towards Adaptive Sensor-cloud for Internet of Things

10.12928/telkomnika.v16i6.11557
I Made; Universitas Pelita Harapan Murwantara , Hendra; Universitas Pelita Harapan Tjahyadi , Pujianto; Universitas Pelita Harapan Yugopuspito , Arnold; Universitas Pelita Harapan Aribowo , Irene A.; Universitas Pelita Harapan Lazarusli
The emerge of the Internet of Things (IoT) data as a commodity to optimize public services such as Fishing Locator has made sensor-cloud an important object. When sensors that are members of multiple IoT gateways can inter-operate at the same time for more than one application, it will reduce cost to deploy IoT infrastructure. However, reliability has also developed as the most important aspect for real-time data collection that should be streamed constantly. Due to uncertainty factors sensors failure is potentially occurred, then an adaptive approach should be addressed into this as to guarantee the flow of streaming data. This paper proposed an adaptive sensor-cloud mechanism to manage the reliability by using a runtime model approach where a transition model and dynamic software product line engineering will take place to weaving the system. Our technique is comparable to other approaches and can be implemented in many types of Cloud-based services.
Volume: 16
Issue: 6
Page: 2771-2781
Publish at: 2018-12-01

Thermodynamic Performance and Wave Propagation Sensor System of Fiber Bragg Grating in Liquid Media

10.12928/telkomnika.v16i6.9563
Romi F.; Universitas Riau Syahputra , Ridho; Baristand Industri Banda Aceh Kurniawan , Yunita I.; Universitas Riau Lubis , Mesra; Universitas Riau Sania , Okfalisa; UIN Suska Okfalisa , Saktioto; Universitas Riau Saktioto
Although the measurement of liquids temperature is commonly used by Fiber Bragg Grating (FBG) sensor but its thermodynamic performance has interesting phenomena. This paper proposes the measurement and simulation of liquids temperature using FBG. Laser diode was launched into human blood, water, and vegetable oil, then transmitted power is measured by optical powermeter to determine its corresponding temperature. The results showed that the increasing temperature changes led to the widening of the wave shift. The largest change of wavelength is water temperature and the smallest One is vegetable oil temperature. Increase in liquid temperature causes the output power is greater. FBG simulation of sine and square function are also designed for temperature range of 30°C to 41°C with matrix transfer method based on coupled mode theory. Peak value of transmission spectrum of each function is shown by the change of temperature which indicates the sensor is sensitive to sine and square function variations. The peak at temperature of 30°C for each sine and square are -78.32 dB and -102.66 dB and increased to 41°C at 46.72 dB and -79.89 dB, respectively.
Volume: 16
Issue: 6
Page: 2661-2667
Publish at: 2018-12-01

Bank of Extended Kalman Filters for Faults Diagnosis in Wind Turbine Doubly Fed Induction Generator

10.12928/telkomnika.v16i6.10426
Imane; Normandy University/UNIRouen Idrissi , Houcine; Normandy University/UNIRouen Chafouk , Rachid El; USMBA University Bachtiri , Maha; USMBA University Khanfara
In order to increase the efficiency, to ensure availability and to prevent unexpected failures of the doubly fed induction generator (DFIG), widely used in speed variable wind turbine (SVWT), a model based approach is proposed for diagnosing stator and rotor winding and current sensors faults in the generator. In this study, the Extended Kalman Filter (EKF) is used as state and parameter estimation method for this model based diagnosis approach. The generator windings faults and current instruments defects are modelled, detected and isolated with the use of the faults indicators called residuals, which are obtained based on the EKF observer. The mathematical model of DFIG for both healthy and faulty operating conditions is implemented in Matlab/Simulink software. The obtained simulation results demonstrate the effectiveness of the proposed technique for diagnosis and quantification of the faults under study.
Volume: 16
Issue: 6
Page: 2954-2966
Publish at: 2018-12-01

Decision Making in the Tea Leaves Diseases Detection Using Mamdani Fuzzy Inference Method

10.11591/ijeecs.v12.i3.pp1273-1281
Arif Ridho Lubis , Santi Prayudani , Muharman Lubis , Al Khowarizmi
The tea plants (Camellia Sinensis) are small tree species that use leaves and leaf buds to produce tea harvested through a monoculture system. It is an agriculture practice to cultivate one types of crop or livestock, variety or breed on a farm annually. Moreover, the emergence of pests, pathogens and diseases cause serious damages to tea plants significantly to its productivity and quality to optimum worst. All parts of the tea plant such as leaves, stems, roots, flowers and fruits are exposed to these harm lead to loss of yield 7 until 10% per year. The intensity of these attacks vary greatly on particular climate, the degree slope and the plant material used. Therefore, this study analyzes tea leaves as a common part used in recipes to create unique taste and flavor in tea production, especially in agro-industry. The decision making method used is Fuzzy Mamdani Inference as one of model with functional hierarchy with initial input based on established criteria. Fuzzy logic will provide tolerance to the set of value, so that small changes will not result in significant category differences, only affect the membership level on the variable value. Previous method using probabilities have shown 78% tea leaves have been attacked by category C (Gray Blight) while using Mamdani indicated 86% of tea leaves have been infected. In this case, this result pointed out that Fuzzy Mamdani Inferences have more optimal result compare to the previous method.
Volume: 12
Issue: 3
Page: 1273-1281
Publish at: 2018-12-01

Improvement of Auto-Tracking Mobile Robot based on HSI Color Model

10.11591/ijeecs.v12.i3.pp1349-1357
Suresh Sundarajoo , Ahmad Shahrizan Abdul Ghani
Auto tracking mobile robot is a device that able to detect and track a target. For an auto tracking device, the most crucial part of the system is the object identification and tracking of the moving targets. In order to improve the accuracy of identification of object in different illumination and background conditions, the implementation of HSI color model is used in image processing algorithm. In this project HSI-based color filtering algorithm were used for object identification. This is because HSI parameter are more stable in different light and background conditions, so it is selected as the main parameters of this system. Pixy CMUcam5 is used as the vision sensor while Arduino Uno as the main microcontroller that controls all the input and output of the device. Besides that, L293D is used as the motor driver to control the movement of two DC motors that attached to the wheel of the robot. Moreover, two servo motors were used to control the pan-tilt movement of the vision sensor. Experimental results demonstrate that when HSI color-based filtering algorithm is applied to visual tracking it improves the accuracy and stability of tracking under the condition of varying brightness, or even in the low-light-level environment. Besides that, this algorithm also prevents tracking loss due to object color appears in the background.
Volume: 12
Issue: 3
Page: 1349-1357
Publish at: 2018-12-01

Orientation to Happiness as a Predictor of University Students’ Engagement

10.11591/ijere.v7i4.15446
Maria Fernanda Durón-Ramos , Fernanda García Vázquez
There is empirical evidence for a close link between positive personal components and students' engagement in academic activities. Personal well-being is a construct that can be studied from a variety of angles. Recent studies point to the relevance of orientation to happiness examining three types of well-being. The main objective of this study is to test the relationship that orientation to happiness has with university students' engagement at a public institution in northern Mexico. A stratified probabilistic sample of 266 students was used. The internal consistency of the scales was analyzed using the SPSS package and a model of structural equations in the EQS program. Results indicate is a direct and significant relationship between the orientation to happiness and the students' engagement. This supports the importance of promoting positive factors in students to improve their academic and personal development.
Volume: 7
Issue: 4
Page: 294-298
Publish at: 2018-12-01

Numerical Method for Evaluating E-Cash Security

10.12928/telkomnika.v16i6.9811
Dany Eka; Bandung Institute of Technology Saputra , Sarwono; Bandung Institute of Technology Sutikno , Suhono Harso; Bandung Institute of Technology Supangkat
Security evaluations of electronic cash (e-cash) schemes usually produce an abstract result in the form of a logical proof. This paper proposes a new method of security evaluation that produces a quantitative result. The evaluation is done by analyzing the protocol in the scheme using the Markov chain technique. This method calculates the probability of an attack that could be executed perfectly in the scheme’s protocol. As proof of the effectiveness of our evaluation method, we evaluated the security of Chaum’s untraceable electronic cash scheme. The result of our evaluation was compared to the evaluation result from the pi-calculus method. Both methods produced comparable results; and thus, both could be used as alternative methods for evaluating e-cash security.
Volume: 16
Issue: 6
Page: 2668-2675
Publish at: 2018-12-01

Proposed Model for Interference Estimation in Code Division Multiple Access

10.12928/telkomnika.v16i6.10330
Dalal Kanaan; Al-Mustansiryah University Taher , Adheed Hassan; Al-Mustansiryah University Sallomi
Cellular CDMA systems are usually affected by interference experienced by users in adjacent cells that decrease the Quality of Services in wireless communication network. Hence, interference is the limiting factor of capacity in CDMA cellular and it is one of the problems fighting against the high efficiency of any mobile network. In this paper, a mathematical model to estimate the average number of users contributing in inter-cell interference at the busy hours of CDMA network is proposed. As the power exponent value has significant affect on interferer signal attenuation and hence other-cells interference, measurements were carried through a drive test to determine the received power level at various distance from CDMA base stations at Baghdad. The results obtained show that the power exponent was 2.71. This value was applied in dual-slop path loss model to determine the expected interference factor, and the number of users that can be hold at each cell. Simulations showed that users at a boundary cell generate more interference than those close to the base station. Furthermore, it was denoted that greater number of users caused to increase the interference factor, and greater power exponent value result in interference factor reduction.
Volume: 16
Issue: 6
Page: 2549-2556
Publish at: 2018-12-01

Response of Polycrystalline Solar Cell Outputs to Visible Spectrum and other Light Sources-a Case Study

10.11591/ijece.v8i6.pp4096-4103
Ayman Y. Al-Rawashdeh , Omar Albarbarawi , Ghazi Qaryouti
In this case study, two polycrystalline solar modules were installed outdoors (irradiated by sunlight) and indoors (irradiated by artificial lights). The solar cells in both cases were installed using different color filters that allowed the passage of certain light frequencies. The amount of energy produced by each module were measured and compared to a reference module with no filter. The results indicated the variable response of polycrystalline solar cells to natural and artificial light sources, being more responsive in both cases to red band color as could be deduced from their % current outputs (72.5% sunlight radiation; 84.38% artificial light sources). Other colors, including yellow, green, orange and violet afforded acceptable outputs. The results indicated that electrical outputs of indoor solar cells decreased when colored filters were used, but red filter in general afforded the maximum outputs, for both the artificially radiated indoor and naturally radiated outdoor solar cells. The case study suggests the possible complementary advantage of using indoor mounted solar cells for the production of electricity during artificial illumination period of the day.
Volume: 8
Issue: 6
Page: 4096-4103
Publish at: 2018-12-01

A Novel Structure of a Wideband Zero-Bias Power Limiter for ISM Band

10.12928/telkomnika.v16i6.8730
Khalifa; Hassan 1st University Echchakhaoui , Elhassane; Hassan 1st University Abdelmounim , Jamal; Hassan 1st University Zbitou , Hamid; Moulay Ismail University Bennis , Ahmed; Hassan 1st University Errkik , Angel Mediavilla; University of Cantabria Santander Sanchez
In this paper, a new broadband microwave microstrip power limiter is designed and realized. The Power Limiter is based on microstrip technology integrating a Zero Bias commercial Schottky diodes HSMS2820.The power limiter is optimized and validated in two steps. The enhanced and achieved circuit is obtained by concatenating two basic structures. The final circuit was validated into simulation by using ADS solver. Finally this circuit was realized and tested. Simulation and measurement results are in a good agreement. The final circuit achieves a limiting rate of 14 dB with a threshold input power level of 0 dBm until a maximum input power level of 30 dBm.
Volume: 16
Issue: 6
Page: 2481-2491
Publish at: 2018-12-01

Modified DCT-based Audio Watermarking Optimization using Genetics Algorithm

10.12928/telkomnika.v16i6.10111
Ledya; Telkom University Novamizanti , Gelar; Telkom University Budiman , Irma; Telkom University Safitri
Ease process digital data information exchange impact on the increase in cases of copyright infringement. Audio watermarking is one solution in providing protection for the owner of the work. This research aims to optimize the insertion parameters on Modified Discrete Cosine Transform (M-DCT) based audio watermarking using a genetic algorithm, to produce better audio resistance. MDCT is applied after reading host audio, then embedding in MDCT domain is applied by Quantization Index Modulation (QIM) technique. Insertion within the MDCT domain is capable of generating a high imperceptible watermarked audio due to its overlapping frame system. The system is optimized using genetic algorithms to improve the value of imperceptibility and robustness in audio watermarking. In this research, the average SNR reaches 20 dB, and ODG reaches -0.062. The subjective quality testing on the system obtains an average MOS of 4.22 out of five songs tested. In addition, the system is able to withstand several attacks. The use of M-DCT in audio watermaking is capable of producing excellent imperceptibility and better watermark robustness.
Volume: 16
Issue: 6
Page: 2651-2660
Publish at: 2018-12-01

Integrated Analytical Hierarchy Process and Objective Matrix in Balanced Scorecard Dashboard Model for Performance Measurement

10.12928/telkomnika.v16i6.9648
Okfalisa; Sultan Syarif Kasim State Islamic University of Riau Okfalisa , Septia; Sultan Syarif Kasim State Islamic University of Riau Anugrah , Wresni; Sultan Syarif Kasim State Islamic University of Riau Anggraini , Muhammad; Sultan Azlan Shah University Malaysia Absor , S.S.M.; Universiti Teknologi MARA Fauzi , Saktioto; Universitas Riau Saktioto
Measuring organizational performance is pivotal for a comprehensive understanding of strengths, weaknesses and to improve the quality of any organization’s performance. Balanced Scorecard (BSC) is the strategic evolution tool that is widely used to measure the organizational performances, and achievements from various aspects, both financial and non-financial. In this research, BSC was not only a straight jacket concept but also a high potential tool for measuring and managing tangible and accurate data through the application of several methods. This research weighted the variables of BSC based on significance values of Analytical Hierarchy Process (AHP) and Optimization of Measurement with Objective Matrix (OMAX). Moreover, a recommendation analysis was given based on the cause and effect analysis of variables and the achievement of Key Performance Indicators (KPIs). The flow of information, data, and performance measurement processes were designed into Business Intelligence (BI) software development i.e. BI-MonevDash. The framework and software BI-MonevDash proposed can be used as a new chosen tool for measuring and monitoring organizational performance. Recommendations could facilitate the leaders in decision making to improve the organizational performance and reduce risks.
Volume: 16
Issue: 6
Page: 2703-2711
Publish at: 2018-12-01

Anomaly Detection based on Control-flow Pattern of Parallel Business Processes

10.12928/telkomnika.v16i6.10568
Hendra; Institut Teknologi Sepuluh Nopember Darmawan , Riyanarto; Institut Teknologi Sepuluh Nopember Sarno , Adhatus Solichah; Institut Teknologi Sepuluh Nopember Ahmadiyah , Kelly Rossa; Institut Teknologi Sepuluh Nopember Sungkono , Cahyaningtyas Sekar; Institut Teknologi Sepuluh Nopember Wahyuni
The purpose of this paper was to discover an anomalous-free business process model from event logs. The process discovery was conducted using a graph database, specifically using Neo4J tool involving trace clustering and data filtering processes. We also developed a control-flow pattern to address, AND relation between activities named parallel business process. The result showed that the proposed method improved the precision value of the generated business process model from 0.64 to 0.81 compared to the existing algorithm. The better outcome is constructed by applying trace clustering and data filtering to remove the anomaly on the event log as well as discovering parallel (AND) relation between activities.
Volume: 16
Issue: 6
Page: 2809-2816
Publish at: 2018-12-01

Revealing AES Encryption Device Key on 328P Microcontrollers with Differential Power Analysis

10.11591/ijece.v8i6.pp5144-5152
Septafiansyah Dwi Putra , Adang Suwandi Ahmad , Sarwono Sutikno , Yusuf Kurniawan , Arwin Datumaya Wahyudi Sumari
This research demonstrates the revealing of an advanced encryption standard (AES) encryption device key. The encryption device is applied to an ATMEGA328P microcontroller. The said microcontroller is a device commonly used in internet of things (IoT). We measured power consumption when the encryption process is taking place. The message sent to the encryption device is randomly generated, but the key used has a fixed value. The novelty of this research is the creation of a systematic and optimal circuit in carrying the differential power analysis or difference of means (DPA/DoM) technique, so the technique can be applied in key revealing on a microcontroller device by using 500 traces in 120 seconds.
Volume: 8
Issue: 6
Page: 5144-5152
Publish at: 2018-12-01

Multiuser Detection with Decision-Feedback Detectors and PIC in MC-CDMA System

10.12928/telkomnika.v16i6.9448
Leila; Badji Mokhtar University Sahraoui , Djemil; Badji Mokhtar University Messadeg , Saliha e; Badji Mokhtar University Hariz , Noureddine; Badji Mokhtar University Doghmane
In this paper we propose an iterative parallel decision feedback (P-DF) receivers associated with parallel interference cancellation (PIC) for multicarrier code division multiple access (MC-CDMA) systems in a Rayleigh fading channel (cost 207). First the most widely detection techniques, minimum mean-squared error MMSE, Maximum Likelihood ML and PIC were investigated in order to compare their performances in terms of Bit Error Rate (BER) with parallel feedback detection P-DFD. A MMSE DF detector that employs parallel decision-feedback (MMSE-P-DFD) is considered and shows almost the same BER performance with MMSE and ML, which present a better result than the other techniques. In a second time, an iterative proposed method based on the multi-stage techniques P-DFD (parallel DFD with two stages) and PIC was exploited to improve the performance of the system.
Volume: 16
Issue: 6
Page: 2578-2587
Publish at: 2018-12-01
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