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29,922 Article Results

Uric acid detection in visible spectrum

10.12928/telkomnika.v18i4.14993
Afiqah; Universiti Tun Hussein Onn Malaysia Yaacob , Nor Hafizah; Universiti Tun Hussein Onn Malaysia Ngajikin , Nurfatihah Che Abd; Universiti Tun Hussein Onn Malaysia Rashid , Siti Hajar Aminah; Universiti Tun Hussein Onn Malaysia Ali , Maslina; Universiti Tun Hussein Onn Malaysia Yaacob , Suhaila; Universiti Teknologi Malaysia Isaak , Noran Azizan; Universiti Tun Hussein Onn Malaysia Cholan
The measurement of uric acid based on the optical absorption at visible light spectrum is investigated and tested. Sensing in the visible region was conducted for determination of suitable wavelength that produces high sensitivity and accuracy performance based on the Beer-Lambert law calculation. In this work, the uric acid is detected by detecting sodium urate as a product of chemical reaction between uric acid with sodium hydroxide buffer. The setup has been tested for uric acid concentration ranging from 15 mg/dL to 85 mg/dL. Three wavelengths have been analyzed which are 460 nm, 525 nm and 630 nm. Measured data at 460nm wavelength exhibits the highest sensitivity, which is 0.0012 (mg/dL)-with 86.51% accuracy. Detection of uric acid at visible light spectrum offers a low-cost sensor based on visible LEDs and photodiode is possible to be realized.
Volume: 18
Issue: 4
Page: 2035-2041
Publish at: 2020-08-01

A steepest descent algorithm for the optimal control of a cascaded hydropower system

10.11591/ijece.v10i4.pp4136-4144
Olalekan Ogunbiyi , Cornelius T. Thomas , Oludare Y. Ogundepo , Isaac O. A. Omeiza , Jimoh Akanni , B. J. Olufeagba
Optimal power generation along the cascaded Kainji-Jebba hydroelectric power system had been very difficult to achieve. The reservoirs operating heads are being affected by possible variation in impoundments upstream, stochastic factors that are weather-related, availability of the turbo-alternators and power generated at any time. Proposed in this paper, is an algorithm for solving the optimal release of water on the cascaded hydropower system based on steepest descent method. The uniqueness of this work is the conversion of the infinite dimensional control problem to a finite one, the introduction of clever techniques for choosing the steepest descent step size in each iteration and the nonlinear penalty embedded in the procedure. The control algorithm was implemented in an Excel VBA® environment to solve the ormulated Lagrange problem within an accuracy of 0.03%. It is recommended for use in system studies and control design for the optimal power generation in the cascaded hydropower system.
Volume: 10
Issue: 4
Page: 4136-4144
Publish at: 2020-08-01

A hybrid constructive algorithm incorporating teaching-learning based optimization for neural network training

10.11591/ijece.v10i4.pp3725-3733
Mahdieh Khorashadizade , Morteza Jouyban , Mohammadreza Asghari Oskoei
In neural networks, simultaneous determination of the optimum structure and weights is a challenge. This paper proposes a combination of teaching-learning based optimization (TLBO) algorithm and a constructive algorithm (CA) to cope with the challenge. In literature, TLBO is used to choose proper weights, while CA is adopted to construct different structures in order to select the proper one. In this study, the basic TLBO algorithm along with an improved version of this algorithm for network weights selection are utilized. Meanwhile, as a constructive algorithm, a novel modification to multiple operations, using statistical tests (MOST), is applied and tested to choose the proper structure. The proposed combinatorial algorithms are applied to ten classification problems and two-time-series prediction problems, as the benchmark. The results are evaluated based on training and testing error, network complexity and mean-square error. The experimental results illustrate that the proposed hybrid method of the modified MOST constructive algorithm and the improved TLBO (MCO-ITLBO) algorithm outperform the others; moreover, they have been proven by Wilcoxon statistical tests as well. The proposed method demonstrates less average error with less complexity in the network structure.
Volume: 10
Issue: 4
Page: 3725-3733
Publish at: 2020-08-01

Identity-based threshold group signature scheme based on multiple hard number theoretic problems

10.11591/ijece.v10i4.pp3695-3701
Nedal Tahat , Ashraf A. Tahat
We introduce in this paper a new identity-based threshold signature (IBTHS) technique, which is based on a pair of intractable problems, residuosity and discrete logarithm. This technique relies on two difficult problems and offers an improved level of security relative to an individual hard problem. The majority of the denoted IBTHS techniques are established on an individual difficult problem. Despite the fact that these methods are secure, however, a prospective solution of this sole problem by an adversary will enable him/her to recover the entire private data together with secret keys and configuration values of the associated scheme. Our technique is immune to the four most familiar attack types in relation to the signature schemes. Enhanced performance of our proposed technique is verified in terms of minimum cost of computations required by both of the signing algorithm and the verifying algorithm in addition to immunity to attacks.
Volume: 10
Issue: 4
Page: 3695-3701
Publish at: 2020-08-01

Plant acoustic frequency technology control system to increase vegetative growth in red-lettuce

10.12928/telkomnika.v18i4.14158
Yusuf; Universitas Brawijaya Hendrawan , Adamsyah Harika; Universitas Brawijaya Putra , Sumardi Hadi; Universitas Brawijaya Sumarlan , Gunomo; Universitas Brawijaya Djoyowasito
The application of plant acoustic frequency technology (PAFT) can spur plant growth, increase productivity, immune system, quality, and extend the shelf life of agricultural products after harvest. The application of sound waves in plants can stimulate the opening of the stomata to optimally absorb nutrients and water. This study aims to determine the effect of frequency and time of PAFT exposure by utilizing Javanese gamelan traditional music on the vegetative growth of red-lettuce (Lactuca sativa var.). Javanese gamelan music used was titled Puspawarna with variations in the frequency of 3-5, 7-9, and 11-13 kHz. The variation of exposure time of sound waves was 1, 2, and 3 hours. PAFT exposure was given routinely in the morning and evening. The results of this study indicated that the best treatment was at 3-5 kHz with an exposure time of 2 hours. This treatment gave a significantly better effect when compared to plants without PAFT. The best combination of frequency and time of PAFT exposure produced 10 leaves, plant height of 9.4 cm, wet weight of 4 g, dry weight of 0.22 g, leaf area of 27.19 cm2, leaf red mean of 63, and stomata opening width of 145.44~206.59 µm.
Volume: 18
Issue: 4
Page: 2042-2052
Publish at: 2020-08-01

Perspectives on the challenges of leadership in schools to improve student learning systems

10.11591/ijere.v9i3.20485
Ali Taufik , Zen Istiarsono
This study is an analysis of the challenges of leaders in schools to improve learning systems, trying to do an analysis of the six aspects of analysis during the study. The main contribution of this research is related to how to deal with challenges in improving learning systems in schools that have so far faced challenges and obstacles, and these need to be analyzed and solutions. This study uses a qualitative method with a case study model, because this researcher is a case that must be disclosed and found a solution, looking at the gap between quality, performance and leadership in several schools that are the object of research and this research lasted for several years. four months (18 weeks), the time is indeed quite short, but researchers try to use this time effectively to produce something useful. In this case involving eight school leaders, as participants, the results of the application of the six aspects of indicators were able to improve teacher performance and from changes in the learning system as well. can be significantly improved as evidenced by the results of evaluating student learning, this research does indeed need to be deepened comprehensively. The author measures the success rate of these indicators by using a cluster system (individually intervening) individually either for the principal or when assessing students, so the writer can see the improvement.
Volume: 9
Issue: 3
Page: 600-606
Publish at: 2020-08-01

Strategy to determine the foot plantar center of pressure of a person through deep learning neural networks

10.12928/telkomnika.v18i4.15200
Henry Hernández; Universidad Distrital Francisco José de Caldas Martínez , Holman Montiel; Universidad Distrital Francisco José de Caldas Ariza , Luz Andrea Gaviria; Universidad Internacional de la Rioja Roa
Some case studies treated by physiotherapists or orthopedists to measure the alignment of the lower extremities during a gait cycle are based on empirical methods of visual observation. This methodology does not guarantee total success, since it depends on the experience of the specialist, what can cause irreversible damage to patients, such as: hip displacement, wear and overload of the joints of a single lower limb. Although, this problem has been addressed in the investigation by means of devices implementation with sensors or methods of processing sequences of images and videos, this topic is still under investigation because the current methods depend on many external elements and data given by an expert in the area. Therefore, this paper proposes a partial solution to this problem by systematizing the experience of a specialist through a computational learning method.
Volume: 18
Issue: 4
Page: 1954-1961
Publish at: 2020-08-01

Indonesian news classification using convolutional neural network

10.11591/ijeecs.v19.i2.pp1000-1009
Muhammad Ali Ramdhani , Dian Sa’adillah Maylawati , Teddy Mantoro
Every language has unique characteristics, structures, and grammar. Thus, different styles will have different processes and result in processed in natural language processing (NLP) research area. In the current NLP research area, data mining (DM) or machine learning (ML) technique is popular, especially for deep learning (DL) method. This research aims to classify text data in the Indonesian language using convolutional neural network (CNN) as one of the DL algorithms. The CNN algorithm used modified following the Indonesian language characteristics. Thereby, in the text pre-processing phase, stopword removal and stemming are particularly suitable for the Indonesian language. The experiment conducted using 472 Indonesian news text data from various sources with four categories: ‘hiburan’ (entertainment), ‘olahraga’ (sport), ‘tajuk utama’ (headline news), and ‘teknologi’ (technology). Based on the experiment and evaluation using 377 training data and 95 testing data, producing five models with ten epoch for each model, CNN has the best percentage of accuracy around 90,74% and loss value around 29,05% for 300 hidden layers in classifying the Indonesian News data.
Volume: 19
Issue: 2
Page: 1000-1009
Publish at: 2020-08-01

Software engineering model based smart indoor localization system using deep-learning

10.12928/telkomnika.v18i4.14318
Zainab Mohammed; University of Technology-Iraq Resan , Muayad Sadik; University of Technology-Iraq Croock
During the last few years, the allocation of objects or persons inside a specific building is highly required. It is well known that the global positioning system (GPS) cannot be adopted in indoor environment due to the lack of signals. Therefore, it is important to discover a new way that works inside. The proposed system uses the deep learning techniques to classify places based on capturing images. The proposed system contains two parts: software part and hardware part. The software part is built based on software engineering model to increase the reliability, flexibility, and scalability. In addition, this part, the dataset is collected using the Raspberry Pi III camera as training and validating data set. This dataset is used as an input to the proposed deep learning model. In the hardware part, Raspberry Pi III is used for loading the proposed model and producing prediction results and a camera that is used to collect the images dataset. Two wheels’ car is adopted as an object for introducing indoor localization project. The obtained training accuracy is 99.6% for training dataset and 100% for validating dataset.
Volume: 18
Issue: 4
Page: 1904-1916
Publish at: 2020-08-01

A simplified spatial Modulation MISO-OFDM scheme

10.12928/telkomnika.v18i4.13873
Vian S.; Al-Rafidain University College Al-Doori , Emad H.; Al-Nahrain University Al-Hemiary
Index modulation is one of the promising techniques for future communications systems due to many improvement over the classical Orthogonal frequency division multiplexing systems such as single RF chain, increased throughput for the same modulation order, achieved tradeoff between the efficiencies of the power and the spectral, and elimination of inter-channel interference. Many forms of index modulation researches exist where symbols are conveyed in antennas, subcarriers, time slots, and the space-time matrix.  Spatial modulation is one member of index modulation family where symbols are conveyed in activating transmit/receive antennas. In this paper, a modification to a standard multiple input single output scheme by integrating spatial modulation using simplified mathematical procedure is achieved. In the transmitter side, data and activation symbols are distributed simultaneously using mathematical module and floor functions. At the receiver, a simplified maximum likelihood detector is used to obtain transmitted pair of symbols. To verify this, MATLAB SIMULINK is used to simulate a downlink system where spatial modulation is applied to a base station. Results for different transmit antenna number and modulation order are obtained in the form of bit error rate versus signal to noise ratio.
Volume: 18
Issue: 4
Page: 1738-1745
Publish at: 2020-08-01

Source current harmonic mitigation of distorted voltage source by using shunt active power filter

10.11591/ijece.v10i4.pp3967-3977
Muhammad Ossama Mahmoud , Wael Mamdouh , Hamdy Khalil
In this paper, three-phase, four-wire shunt active power filter (SAPF) is utilized to mitigate system harmonics of distorted voltage source for unbalanced and nonlinear loads. Basically, the source voltage should be pure sinusoidal waveform to get a good mitigation of source current harmonics. In this under study system, the source voltage is assumed to be harmonic distortion non-sinusoidal voltage source. The phase locked loop (PLL) control circuit is wielded for extracting the fundamental component of the distorted source voltage to use it as an input signal to the SAPF control. Another input signal to the SAPF is the distorted load current. The SAPF control system uses (p-q) theory to calculate the optimum instantaneous current to be injected by the SAPF to mitigate the source current harmonics even the source voltage is harmonic distorted. MATLAB/SIMULINK software package is utilized to simulate the system under study. The effect of SAPF is tested when it’s used with and without the PLL control circuit. The simulation results show that, the THD of source current when using the PLL control circuit is improved to comply with the harmonic limits given in the IEEE 519-1992 and IEC 61000-4-7 standards.
Volume: 10
Issue: 4
Page: 3967-3977
Publish at: 2020-08-01

Training of trainers: An action-based research for improving the pedagogical skills of academicians

10.11591/ijere.v9i3.20327
Bayram Özer , Volkan Duran , Mustafa Tekke
Based on the philosophy of lifelong education, private/public institutions and organizations invest in continuous training of human resources. Universities also organize in-service trainings regarding the general principles of teaching and learning in the context lifelong learning activities for the development of the pedagogical skills of the academicians who have difficulty in using teaching skills and principles in the courses in their universities. Therefore, a Project entitled as Training of Trainers based on action research based on qualitative research design was carried out for aiming at providing pedagogical education for the academicians who work in different departments of Ondokuz Mayis University who are experts in different disciplines but who do not have pedagogical background in order to gain experience in basic skills and principles in education area so as to improve the quality of education in this way. During the project, which lasted for a total of 2 years, 246 academicians were trained in 24 different subjects, the opinions of the participants were taken and the distribution of these views was reflected in the tables in text. Finally, the asymptotic Significance (2-sided) for Pearson Chi-Square indicates of the yes/no answer indicates that there is a dramatic change regarding the effectiveness of the program. It is seen that it meets the needs of academicians. Therefore, the program based on action research design shows that such in-service pedagogical programs could be useful for higher education in this respect.
Volume: 9
Issue: 3
Page: 704-715
Publish at: 2020-08-01

SVC device optimal location for voltage stability enhancement based on a combined particle swarm optimization-continuation power flow technique

10.12928/telkomnika.v18i4.13073
Oum El Fadhel Loubeba; Dr. Moulay Tahar University Bekri , Abdellah; University of Quebec in Chicoutimi UQAC Chehri , Tounsia; Mouloud Mammeri University Djamah , Mohamed Karim; DjillaliLiabès University Fellah
The increased power system loading combined with the worldwide power industry deregulation requires more reliable and efficient control of the power flow and network stability. Flexible AC transmission systems (FACTS) devices give new opportunities for controlling power and enhancing the usable capacity of the existing transmission lines. This paper presents a combined application of the particle swarm optimization (PSO) and the continuation power flow (CPF) technique to determine the optimal placement of static var compensator (SVC) in order to achieve the static voltage stability margin. The PSO objective function to be maximized is the loading factor to modify the load powers. In this scope, two SVC constraints are considered: the reference voltage in the first case and the total reactance and SVC reactive power in the second case. To test the performance of the proposed method, several simulations were performed on IEEE 30-Bus test systems. The results obtained show the effectiveness of the proposed method to find the optimal placement of the static var compensator and the improvement of the voltage stability.
Volume: 18
Issue: 4
Page: 2101-2111
Publish at: 2020-08-01

Active power ouptut optimization for wind farms and thermal units by minimizing the operating cost and emissions

10.11591/ijece.v10i4.pp3412-3422
Nazha Cherkaoui , Abdelaziz Belfqih , Faissal El Mariami , Jamal Boukherouaa , Abdelmajid Berdai
In recent years, many works have been done in order to discuss economic dispatch in which wind farms are installed in electrical grids in addition to conventional power plants. Nevertheless, the emissions caused by fossil fuels have not been considered in most of the studies done before. In fact, thermal power plants produce important quantities of emissions for instance, carbon dioxide (CO2) and sulphur dioxide (SO2) that are harmful to the environment. This paper presents an optimization algorithm with the objective to minimize the emission levels and the production cost. A comparison of the results obtained with different optimization methods leads us to opt for the grey wolf optimizer technique (GWO) to use for solving the proposed objective function. First, the method used to estimate the wind power of a plant is presented. Second, the economic dispatch models for wind and thermal generators are presented followed by the emission dispatch model for the thermal units.Then, the proposed objective function is formulated. Finally, the simulation results obtained by applying the GWO and other known optimization techniques are analysed and compared.
Volume: 10
Issue: 4
Page: 3412-3422
Publish at: 2020-08-01

Fuzzy logic applications for data acquisition systems of practical measurement

10.11591/ijece.v10i4.pp3441-3450
Muhammad Haddin , Arief Marwanto , Agus Suprajitno , Munaf Ismail
In laboratory works, the error in measurement, reading the measurring devices, similarity of experimental data and lack of understanding of practicum materials are often found. These will lead to the inacurracy and invalid in data obtanined. As an alternative solution, application of fuzzy logic to the data acquisition system using a web server can used. This research focuses on the design of data acquisition systems with the target of reducing the error rate in measuring experimental data on the laboratory. Data measurement on laboratory practice module is done by taking the analog data resulted from the measurement. Furthermore, the data are converted into digital data via arduino and stored on the server. To get valid data, the server will process the data by using fuzzy logic method. The valid data are integrated into a web server so that it can be accessed as needed. The results showed that the data acquisition system based on fuzzy logic is able to provide recommendation of measurement result on the lab works based on the degree value of membership and truth value. Fuzzy logic will select the measured data with a maximum error percentage of 5% and select the measurement result which has minimum error rate.
Volume: 10
Issue: 4
Page: 3441-3450
Publish at: 2020-08-01
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