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29,922 Article Results

Enhancing DSSC conversion efficiency by ozone-treated TiO2 photoanode and optimum CNT/PDDA counter electrode

10.11591/ijece.v10i3.pp2926-2933
Yoshiki Kurokawa , Dang Trang Nguyen , Ryota Fujimoto , Kozo Taguchi
The conversion efficiency of dye-sensitized solar cells (DSSCs) depends on the performance of the photoanode and the counter electrode. In this paper, UV-ozone treatment has been applied to the photoanode to clean and increase the hydrophilicity of the photoanode. As a result, the dye adsorption capacity was improved. Also, low-cost multiwalled carbon nanotube (CNT) combined with poly (diallyl dimethylammonium chloride) (PDDA) was used to fabricate the counter electrode. The CNT/PDDA counter electrode was optimized to maximize its performance. By using the ozone-treated photoanode and optimum CNT/PDDA counter electrode, the conversion efficiency has increased by about 64%.
Volume: 10
Issue: 3
Page: 2926-2933
Publish at: 2020-06-01

Architecture of the global navigation satellite system for maritime applications

10.12928/telkomnika.v18i3.15640
Dimov Stojce; Durban University of Technogy Ilcev
This paper introduces architecture of the global navigation satellite system (GNSS) networks in the function of the maritime space communications, navigation and surveillance (CNS) for enhanced navigation and positioning of vessels deploying passive, active and hybrid global determination satellite systems (GDSS) networks. These GNSS networks have to enhance safety and control oceangoing ships in navigation across the ocean and inland waters, to improve logistics and freight of goods, security of crew and passengers onboard ships. The maritime GNSS networks integrated with geostationary earth orbit (GEO) satellite constellations are providing important global satellite augmentation systems (GSAS) architecture, which is established by two first generations known GNSS as GNSS-1 infrastructures. The GNSS-1 network is the composition of two subnets such as the US global position system (GPS) and Russian global satellite navigation system (GLONASS). Both GNSS-1 networks play a significant contribution in very precise timing, tracking, guidance, determination and navigation of the oceangoing ships. At this point, both GNSS-1 networks, GPS and GLONASS, are used in maritime and many other mobile and fixed applications to provide enhanced accuracy and high integrity monitoring usable for positioning of the oceangoing ships. To provide improvements of GNSS-1 network it will be necessary to carry out their augmentation within several regional satellite augmentation systems (RSAS) as integration parts of GSAS infrastructures.
Volume: 18
Issue: 3
Page: 1600-1609
Publish at: 2020-06-01

Design and control technique for single phase bipolar H-bridge inverter connected to the grid

10.11591/ijece.v10i3.pp3057-3065
Linda Hassaine , Mohamed Rida Bengourina
The power quality injected into the grid and the performance of the converter system depend on the quality of the inverter current control. This paper proposes a design and control technique for a photovoltaic inverter connected to the grid based on the digital pulse-width modulation (DSPWM) which can synchronise a sinusoidal output current with a grid voltage and control a power factor. The current injected must be sinusoidal with reduced harmonic distortion. The connected PV system is based on H-Bridge inverter controlled by bipolar PWM Switching. The current control technique and functional structure of this system are presented and simulated. Detailed analysis, Simulations results of output voltage and current waveform demonstrate the contribution of this approach to determinate the suitable control of the system. A digital design of a generator PWM using VHDL is proposed and implemented on an Xilinx FPGA and it has been validated with experimental results. As a result, the proposed inverter implementation is simple, and it becomes an attractive solution for low power grid connected applications.
Volume: 10
Issue: 3
Page: 3057-3065
Publish at: 2020-06-01

Automated monitoring and controlling pH levels for hydroponics cultivation technique

10.11591/ijeecs.v18.i3.pp1236-1243
Mohammad Farid Saaid , Ahmad Ihsan Mohd Yassin , Nooritawati Md Tahir
A hydroponics plant can grow healthily with sufficient nutrient, temperature, light, humidity as well as pH level that is indeed vital in ensuring the plants will absorb maximum nutrient elements required. This paper presents automated monitoring and controlling pH levels for the hydroponic cultivation technique. In this study, automated monitoring and controlling of pH levels are developed specifically for the hydroponic cultivation technique. There are three main methods that involved in the development of the system namely hardware, programming and functionality test. Firstly, users need to set the maximum and minimum pH levels as required by the plant. Then, the pH sensor will monitor the real-time pH level of the water. A syringe pump that contains a pH up solution (alkaline) and a pH down solution (acid) will drip the solutions to neutralize the water content if the water pH level is not within the stated ranges as set by the user. Results showed that the automated monitoring and controlling pH levels were successfully developed and functionality was tested and confirmed as desired. The syringe pumps responded perfectly upon changes of the water pH value based on the validation done that showed 100% accuracy of the syringe pump responds. 
Volume: 18
Issue: 3
Page: 1236-1243
Publish at: 2020-06-01

Faulty sensor detection using multi-variate sensors in internet of things (IoTs)

10.11591/ijeecs.v18.i3.pp1391-1399
Khaldoon Ammar Omar , Ahmed Dhahir Malik , Ansar Jamil , Hasan Muwafeq Gheni
IoT devices are lightweight and have limited computational capabilities often exposed to harsh environments, which can cause failure on the IoT devices [1, 2].  The failure on the IoT devices is also caused due to limited battery life, hardware failure or human mistakes. Sensor faults can be categorized under one type of hardware failure, such as sensor burn, reduced sensor sensitivity and malfunctioned sensors.  Any faulty on the IoT devices can cause a problem on the overall operation of the IoT system. Traditional ways in the management of IoT devices is a maintenance officer require to check each device every day  [1, 3]. Any faulty devices found needs to be fixed or replaced. This traditional method is not practical and very challenging especially in the management of a large scale deployment of IoT consist of hundreds or thousands devices. Because of this, we proposed a faulty sensor detection and identification mechanism using multivariate sensors. Two methods of decision making are introduced in detecting faulty sensors, which are logical and correlation method that implemented in smart parking system and smart agriculture system accordingly. The logical method compares state of all sensors (ultrasound, IR and hall-effect) in the smart parking system either a parking lot is occupied or available, and then determine the condition of the sensors. The drawback of this method is not able to detect faulty sensor properly for a constant fault, which the sensor reading remains the same value. The correlation method calculates the correlation between all sensors (soil moisture, soil temperature and soil water) in the smart agriculture system. This method uses a moving window technique to calculate the correlation for all sensor over time. Any incomparable and uncorrelated sensor readings means a presence of faulty sensors. Based on the experiment results, the findings shows that the proposed faulty sensor detection mechanism is working properly in detecting faulty sensor in a timely manner.
Volume: 18
Issue: 3
Page: 1391-1399
Publish at: 2020-06-01

Correlating spiritual and emotional intelligence with academic performance among Pakistani students

10.11591/ijere.v9i2.20476
Jamshid Ali Turi , Anita Abdul Rani , Abidin Imaduddin , Fatimah Binti Mahmud , Alaeldeen Al Adresi
Continuous learning works like a blood for organization and individuals to proceed and succeed. Underdeveloped countries need to address their academic issues. Academic prosperity is linked to economy and technology disruptions so it’s an important element to bring underdeveloped countries up to the mark to thrive and survive in this technical era. Academic prosperity depends upon student's enthusiastic attitude and their emotional and spiritual intelligences. This study was conducted in learning organizations to see the impact of emotional and spiritual intelligences on academic performance. Population of the study is the academic institutes of Pakistan. Data were collected using cross-sectional questionnaire-based survey from 113 students in Pakistan. The findings provide positive and significant correlations among the types of intelligences and academic performance. Data was analyzed using SPSS and the results were verified using statistical methods like correlation, regression, ANNOVA, Cronbach alpha and means. This study highlights the role of emotional intelligence and spiritual intelligence on academic performance and found out that it has the most demanding and significant effect on the academic performance, therefore it needs better integration in academic practices, routine and culture.
Volume: 9
Issue: 2
Page: 278-284
Publish at: 2020-06-01

Contour evolution method for precise boundary delineation of medical images

10.12928/telkomnika.v18i3.14746
Friska; Universitas Multimedia Nusantara Natalia , Hira; Universitas Multimedia Nusantara Meidia , Nunik; Universitas Multimedia Nusantara Afriliana , Julio Christian; Universitas Multimedia Nusantara Young , Sud; Universitas Multimedia Nusantara Sudirman
Image segmentation is an important precursor to boundary delineation of medical images. One of the major challenges in applying automatic image segmentation in medical images is the imperfection in the imaging process which can result in inconsistent contrast and brightness levels, and low image sharpness and vanishing boundaries. Although recent advances in deep learning produce vast improvements in the quality of image segmentation, the accuracy of segmentation around object boundaries still requires improvement. We developed a new approach to contour evolution that is more intuitive but shares some common principles with the active contour model method. The method uses two concepts, namely the boundary grid and sparse boundary representation, as an implicit and explicit representation of the boundary points. We tested our method using lumbar spine MRI images of 515 patients. The experiment results show that our method performs up to 10.2 times faster and more flexible than the geodesic active contours method. Using BF-score contour-based metric, we show that our method improves the boundary accuracy from 74% to 84% as opposed to 63% by the latter method.
Volume: 18
Issue: 3
Page: 1621-1632
Publish at: 2020-06-01

OFDM synchronization system using wavelet transform for symbol rate detection

10.12928/telkomnika.v18i3.14834
Masaru; Waseda University Sawada , Quang Ngoc; Waseda University Nguyen , Mohammed Mustafa; Waseda University Alhasani , Cutifa; President University Safitri , Takuro; Waseda University Sato
In radio communications, using wavelet signal analysis to recover the symbol rate timing clock of orthogonal frequency-division multiplexing (OFDM) is a new approach that can tolerate signal distortion from intersymbol interference (ISI) and intercarrier interference of encoding digital data on multiple carrier frequencies. Typically, the reception synchronization with wavelet signal analysis in OFDM can improve the performance over the fourier transform-based OFDM. However, a synchronization procedure that is stable against distortion and noise is essential to diminish the symbol synchronization establishment and operation sampling period. In this paper, we propose an OFDM synchronization system and analyze the impact of the wavelet denoise procedure on the OFDM system, which extracts the symbol rate of the OFDM frame. The evaluation results show that the proposed system can optimize the frequency window size to enable an efficient timing and frequency offset estimation with high and stable performance in terms of bit error rate (BER) and Frame Error Rate (FER) especially when the value of EbN0 (a normalized signal-to-noise ratio SNR measure) is greater than 8 dB, thanks to the wavelet transform.
Volume: 18
Issue: 3
Page: 1658-1670
Publish at: 2020-06-01

Velocity control of ROV using modified integral SMC with optimization tuning based on Lyapunov analysis

10.12928/telkomnika.v18i3.14781
Syadza Atika; Politeknik Elektronika Negeri Surabaya Rahmah , Eko Henfri; Politeknik Elektronika Negeri Surabaya Binugroho , Raden Sanggar; Politeknik Elektronika Negeri Surabaya Dewanto , Dadet; Politeknik Elektronika Negeri Surabaya Pramadihanto
Remotely Operated Vehicle also known as ROV is a vehicle with high nonlinearity and uncertainty parameters that requires a robust control system to maintain stability. The nonlinearity and uncertainty of ROV are caused by underwater environmental conditions and by the movement of the vehicle. SMC is one of the control systems that can overcome nonlinearity and uncertainty with the given robust system. This work aims to control velocity of the vehicle with proposes the use of modified integral SMC compensate error in ROV and the use of particle swarm optimization (PSO) to optimize the adjustment of SMC parameters. The ROV used in this paper has a configuration of six thrusters with five DoF movements that can be controlled. Modified integral sliding mode is used to control all force direction to increase the convergence of speed error. Adjustment optimization techniques with PSO are used to determine four values of sliding control parameters for five DoF. Using Lyapunov stability approach control law of sliding mode is derived and its global stability proved mathematically. Simulation results are conducted to evaluate the effectiveness of Modified Integral SMC and compared with nonlinear control.
Volume: 18
Issue: 3
Page: 1505-1513
Publish at: 2020-06-01

Disease prediction in big data healthcare using extended convolutional neural network techniques

10.11591/ijaas.v9.i2.pp85-92
Asadi Srinivasulu , Asadi Pushpa
Diabetes Mellitus is one of the growing fatal diseases all over the world. It leads to complications that include heart disease, stroke, and nerve disease, kidney damage. So, Medical Professionals want a reliable prediction system to diagnose Diabetes. To predict the diabetes at earlier stage, different machine learning techniques are useful for examining the data from different sources and valuable knowledge is synopsized. So, mining the diabetes data in an efficient way is a crucial concern. In this project, a medical dataset has been accomplished to predict the diabetes. The R-Studio and Pypark software was employed as a statistical computing tool for diagnosing diabetes.  The PIMA Indian database was acquired from UCI repository will be used for analysis. The dataset was studied and analyzed to build an effective model that predicts and diagnoses the diabetes disease earlier.
Volume: 9
Issue: 2
Page: 85-92
Publish at: 2020-06-01

Smart parking management system using SSGA MQTT and real-time database

10.12928/telkomnika.v18i3.14869
Putri Sandika; Telkom University Juwita , Radya; Telkom University Fadhil , Tri Nopiani; Telkom University Damayanti , Dadan Nur; Telkom University Ramadan
Smart parking system as a part of smart city development has been widely proposed with several research. In this research, proposed a system of parking management application that functions to monitor and control the location of parking slot that can be used by the parking management and parking users. The web application connected to ultrasonic sensor and GPS using MQTT protocol and real-time database. The research used modify algorithm of the SSGA, to optimize the allocation of empty parking slot and MQTT protocol to obtain the faster response time of the system when many users are accessing the website application. The results obtain a variation of sending delays from the client publish to firebase at 4 seconds. Meanwhile, for the sending delay from the broker to firebase the variation was at 2 seconds for each time of data sending.
Volume: 18
Issue: 3
Page: 1243-1251
Publish at: 2020-06-01

Green-emitting Gd2O2S:Tb3+ and red-emitting Y3Al5O12:Cr3+ phosphors: a suitable selection for enhancing color quality of remote phosphor structure

10.12928/telkomnika.v18i3.13626
Nguyen Thi Phuong; Posts and Telecommunications Institute of Technology Loan , Thinh Cong; Ton Duc Thang University Tran
This article demonstrates green-emitting phosphor Gd2O2S:Tb3+ and red-emitting phosphor Y3Al5O12:Cr3+ application in the triple-layer phosphor WLED to enhance optical performance. The arrangement of phosphor layers in the WLED is red phosphor Y3Al5O12:Cr3+ on top, green phosphor Gd2O2S:Tb3+ in the middle, and yellow phosphor YAG:Ce3+ at the bottom. The principal to utilize these phosphor materials is the exploitation of additional red light component and green light component from the green and red phosphor to enrich the color rendering index (CRI) and luminous efficacy. The influences of green phosphor and red phosphor are also estimated with a new quality indicator, the color quality index (CQS). The results show red phosphor Y3Al5O12:Cr3+ enable CRI when its concentration increases while green phosphor exhibits a contrast reaction. Regarding the CQS, the optimal red phosphor concentration for CQS is from 10% to 14%, disregard the concentration in green phosphor. The improvement that applying these two phosphor materials brought comes from limiting the light loss from back-scattering and strengthen chromatic performance through addition red and green light components. These findings can support manufacturers in adapting to modern lighting requirements by improving CRI, CQS and particularly luminous efficiency to more than 40%.
Volume: 18
Issue: 3
Page: 1561-1566
Publish at: 2020-06-01

A general framework of genetic multi-agent routing protocol for improving the performance of MANET environment

10.11591/ijai.v9.i2.pp310-316
Mustafa Hamid Hassan , Mohammed Ahmed Jubair , Salama A. Mostafa , Hazalila Kamaludin , Aida Mustapha , Mohd Farhan Md. Fudzee , Hairulnizam Mahdin
These days, the fields of Mobile Ad hoc Network (MANET) have provided increasing prevalence and consequently, MANET is now a subject of considerable significance for the researchers to instigate research activities. MANET is the collaborative commitment of an assemblage of portable (or mobile) hubs (or nodes) without the necessary mediation of any unified (or centralized) gateway (or access point) or existent framework. There exists a growing inclination or course to embrace MANET for business utilization. MANET is a rising domain of research to give different services in communication to end-clients or consumers. However, these communication services of MANET utilize a large amount of transfer speed (or bandwidth) and a huge measure of web speed. Bandwidth optimization is essential in different information interchanges for fruitful acknowledgement and the application of such a technological innovation. This paper integrates the Genetic Algorithm (GA) and the Multi-Agent System (MAS) to improve the QoS requirements. The proposed framework called Genetic Multi-Agent Routing Protocol (GMARP). The aims of the proposed framework are to utilize the benefits of both approaches in order to fulfil QoS such as (delay, bandwidth, and the number of hops) in the different types of routing conventions (or protocols) such as being (proactive and reactive). In this paper is a simulation scenario to demonstrate the ability of the proposed framework to be satisfied with QoS requirements.
Volume: 9
Issue: 2
Page: 310-316
Publish at: 2020-06-01

Comparison of machine learning performance for earthquake prediction in Indonesia using 30 years historical data

10.12928/telkomnika.v18i3.14756
I Made; Universitas Pelita Harapan Murwantara , Pujianto; Universitas Pelita Harapan Yugopuspito , Rickhen; Universitas Pelita Harapan Hermawan
Indonesia resides on most earthquake region with more than 100 active volcanoes,and high number of seismic activities per year. In order to reduce the casualty, some method to predict earthquake have been developed to estimate the seismic movement. However, most prediction use only short term of historical data to predict the incoming earthquake, which has limitation on model performance. This work uses medium to long term earthquake historical data that were collected from 2 local government bodies and 8 legitimate international sources. We make an estimation of a mediumto-long term prediction via Machine Learning algorithms, which are Multinomial Logistic Regression, Support Vector Machine and Na¨ıve Bayes, and compares their performance. This work shows that the Support Vector Machine outperforms other method. We compare the Root Mean Square Error computation results that lead us into how concentrated data is around the line of best fit, where the Multinomial Logistic Regression is 0.777, Na¨ıve Bayes is 0.922 and Support Vector Machine is 0.751. In predicting future earthquake, Support Vector Machine outperforms other two methods that produce significant distance and magnitude to current earthquake report.
Volume: 18
Issue: 3
Page: 1331-1342
Publish at: 2020-06-01

Maximising system throughput in wireless powered sub-6 GHz and millimetre-wave 5G heterogeneous networks

10.12928/telkomnika.v18i3.15049
Qazwan; Universiti Tun Hussein Onn Malaysia (UTHM) Abdullah , Noorsaliza; Universiti Tun Hussein Onn Malaysia Abdullah , Mohammed; University of Jeddah Balfaqih , Nor Shahida; Universiti Tun Hussein Onn Malaysia Mohd Shah , Shipun; Universiti Tun Hussein Onn Anuar , Akram A.; Universiti Putra Malaysia Almohammedi , Adeeb; Universiti Tun Hussein Onn Malaysia Salh , Nabil; Universiti Teknikal Malaysia Melaka Farah , Vladimir; South Ural State University Shepelev
Millimetre wave (mm-Wave) bands and sub-6 GHz are key technologies in solving the spectrum critical situation in the fifth generation (5G) wireless networks in achieving high throughput with low transmission power. This paper studies the performance of dense small cells that involve a millimetre wave (mm-Wave) band and sub-6 GHz that operate in high frequency to support massive multiple-input-multiple-output systems (MIMO). In this paper, we analyse the propagation path loss and wireless powered transfer for a 5G wireless cellular system from both macro cells and femtocells in the sub-6 GHz (µWave) and mm-Wave tiers. This paper also analyses the tier heterogeneous in downlink for both mm-Wave and sub-6 GHz. It further proposes a novel distributed power to mitigate the inter-beam interference directors and achieve high throughput under game theory-based power constraints across the sub-6 GHz and mm-Wave interfaces. From the simulation results, the proposed distributed powers in femtocell suppresses inter-beam interference by minimising path loss to active users (UEs) and provides substantial power saving by controlling the distributed power algorithm to achieve high throughput.
Volume: 18
Issue: 3
Page: 1185-1194
Publish at: 2020-06-01
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