Browsing by Author "Taskin S."
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Item Fault diagnosis of pneumatic systems with artificial neural network algorithms(2009) Demetgul M.; Tansel I.N.; Taskin S.Pneumatic systems repeat the identical programmed sequence during their operation. The data was collected when the pneumatic system worked perfectly and had some faults including empty magazine, zero vacuum, inappropriate material, no pressure, closed manual pressure valve, missing drilling stroke, poorly located material, not vacuuming the material and low air pressure. The signals of eight sensors were collected during the entire sequence and the 24 most descriptive features of the data were encoded to present to the ANNs. A synthetic data generation process was proposed to train and test the ANNs better when signals are extremely repetitive from one sequence to other. Two artificial neural networks (ANN) were used for interpretation of the encoded signals. The tested ANNs were Adaptive Resonance Theory 2 (ART2), and Back propagation (Bp). ART2 correctly distinguished the perfect and faulty operations at all the tested vigilance values. It classified 11 faulty and 1 normal modes in seven or eight categories at the best vigilance values. Bp also distinguished perfect and faulty operations without even the slightest uncertainty. In less than 10 cases, it had difficulty identifying the 11 types of possible faults. The average estimation error of the Bp was better than 2.1% of the output range on the test data which was created by deviating the encoded values. The ART2 and Bp performance was found excellent with the proposed encoding and synthetic data generation procedures for extremely repetitive sequential data. © 2009 Elsevier Ltd. All rights reserved.Item Spectral analysis for current and temperature measurements in power cables(2009) Taskin S.; Seker S.; Karahan M.; Akinci T.C.This research aims to detect spectral properties under thermal and current variations for power cables. Therefore, spectral diversities are exposed under current unbalances and different load conditions through the spectral analysis techniques. Also, huge load variations are easily detected from the current signals in the time-frequency plane using the short-time frequency analysis. Hence, this study presents the determination of the frequency characteristics and spectral similarities between the phase currents and thermal variations.Item Reverse power data analysis and feature extraction based upon continuous wavelet transform for electric power plants(Praise Worthy Prize S.r.l, 2010) Taskin S.; Seker S.; Irgen B.; Akinci T.C.This study is focused on the investigating of a power plant generator in reverse power condition. For this purpose, reverse power data were collected from a Combined Heat and Power Plant generator protection relay. The reverse power conditions were evaluated by means of the time-frequency and time-scale methods. As a result of this evaluation, it can be said that the time- frequency and time-scale properties of the signals like current, voltage, frequency, active and reactive powers were extracted with all details. © 2010 Praise Worthy Prize S.r.l. - All rights reserved.Item Determination of the spectral properties and harmonic levels for driving an induction motor by an inverter driver under the different load conditions(2011) Taskin S.; Gokozan H.This paper analyses the electrical power quality for the induction motor of 75 kW using the spectral analysis methods. Measurements are carried out by collecting the current and voltage variations in a ceramic factory. Spectral analyzing techniques are applied to the collected data to get the spectral properties. Hence, induction motor operation regions are categorized under three zones. These are no-load condition; transient case from no-load to load and full-load, respectively. Consequently, the variations of the harmonics are compared with each other under these different operation conditions and then the most important characteristics of the harmonics are determined. In this manner, dominant harmonics are obtained as 5th, 7th, 11 th, 13th and 17th harmonics as well as fundamental frequency at 50 Hz.Item Statistical investigation of hydraulic driven circular interpolation motions(2012) Pinar A.M.; Gullu A.; Taskin S.In this study, a twin-axis gantry has been structured to examine hydraulic driven positioning skills of the curvilinear motions based on ISO 230-4 standard entitled 'Circular tests for numerically controlled machine tools'. The system is controlled by a path and position control module of a PLC device. As a result of the experiments conducted based on the full factorial design, the effects of piston diameter, feed rate, radius and their two-way interactions on the circularity error are determined through analysis of variance. Accordingly, minimum circularity error is obtained with the piston diameter of 63 mm, inertia load of 12. 5 kg, radius of 5 mm and feed rate of 50 mm/min as 0. 345 mm. Circularity error increases with the increase of inertia load, radius and feed rate, and declines with the increase of piston diameter. Lastly, piston diameter has the greatest effect on the circularity error change and followed by radius, feed rate, piston diameter-radius, radius-feed rate, piston diameter-feed-rate, inertia load, piston diameter-inertia load, and inertia load-radius factors and interactions. © 2012 Indian Academy of Sciences.Item Spectral and statistical analysis for ferroresonance phenomenon in electric power systems(2012) Seker S.; Akinci T.C.; Taskin S.This study presents our findings on the ferroresonance phenomenon for the Seyitomer-Isiklar part of the Electric Power System of 380 kV in Turkey. In this context, the power spectral density approach and Short-Time Fourier Transforms are applied to the voltage variations for phase R of the sample power network. The findings show that the ferroresonance event can be represented by the interharmonics between 50 and 250 Hz, as well as statistical properties. In addition, a histogram of the ferroresonance region shows a different characteristic from the overall data and the nonferroresonance region. This different characteristic can be defined by an asymmetrical distribution characteristic, and its numerical measure is given by the "Noise to Signal Ratio" of 0.624. © Springer-Verlag 2011.Item A Turkish Gynecologic Oncology Group study of fertility-sparing treatment for early-stage endometrial cancer(John Wiley and Sons Ltd, 2012) Dursun P.; Erkanli S.; Güzel A.B.; Gultekin M.; Tarhan N.C.; Altundag O.; Demirkiran F.; Beşe T.; Yildirim Y.; Bozdag G.; Yarali H.; Simsek T.; Ozcelik B.; Ortaç F.; Taskin S.; Guvenal T.; Ozgul N.; Haberal A.; Vardar M.A.; Dede M.; Yenen M.; Altintas A.; Arvas M.; Ayhan A.Objective: To analyze the results of fertility-sparing treatment of early-stage endometrial cancer (EC) in patients treated at Turkish gynecologic oncology centers, and to present a review of the literature. Methods: Thirteen healthcare centers in Turkey were contacted to determine if they were eligible to participate in the study. Centers that were eligible and agreed to participate were sent a database form to record the demographic characteristics, clinicopathologic findings, and follow-up results for their EC patients. Results: Eleven Turkish healthcare centers provided data on 43 EC patients. Mean duration of treatment was 5 months and mean follow-up was 49 months. In total, 35 (81.4%) patients were tumor free following primary progesterone therapy. Mean time from the end of progesterone therapy to pregnancy was 10.6 ± 4.3 months (range, 3-18 months). Two patients had tumor recurrence during follow-up. The pregnancy rate among the 31 women who actively sought pregnancy was 41.9% (n = 13). Conclusion: Conservative management of early-stage EC in women of reproductive age using oral progestins was effective and did not compromise oncological outcome. Pregnancy in the study patients was achieved spontaneously and artificially. © 2012 International Federation of Gynecology and Obstetrics.Item A proposed artificial neural network model for PEM fuel cells(IEEE Computer Society, 2013) Sari A.; Balikci A.; Taskin S.; Aydin S.Fuel cells convert the chemical energy directly to the electrical energy and hence they are a very favorable alternative energy source. In the literature, there are many studies related to the modeling of fuel cells. Artificial neural networks (ANNs) is one of the promising techniques for modelling nonlinear systems such as fuel cells. The proposed model in this study doesn't require many parameters like other studies. Firstly, training and testing data was obtained the dynamic model of a PEM fuel-cell. Then, proposed ANN model outputs are compared with dynamic model ouputs Simulation results shows that the proposed ANN model can be used very efficiently for PEM fuel-cells without using many parameters. © 2013 The Chamber of Turkish Electrical Engineers-Bursa.Item Fault diagnosis on material handling system using feature selection and data mining techniques(Elsevier B.V., 2014) Demetgul M.; Yildiz K.; Taskin S.; Tansel I.N.; Yazicioglu O.The material handling systems are one of the key components of the most modern manufacturing systems. The sensory signals of material handling systems are nonlinear and have unique characteristics. It is very difficult to encode and classify these signals by using multipurpose methods. In this study, performances of multiple generic methods were studied for the diagnostic of the pneumatic systems of the material handling systems. Diffusion Map (DM), Local Linear Embedding (LLE) and AutoEncoder (AE) algorithms were used for future extraction. Encoded signals were classified by using the Gustafson-Kessel (GK) and k-medoids algorithms. The accuracy of the estimations was better than 90% when the LLE was used with GK algorithm. © 2014 Elsevier Ltd. All rights reserved.Item Inspection of the integrity of a multi-bolt robotic arm using a scanning laser vibrometer and implementing the surface response to excitation method (SuRE)(Prognostics and Health Management Society, 2014) Fekrmandi H.; Rojas J.; Campbell J.; Tansel I.N.; Kaya B.; Taskin S.The integrity of a robotic arm was examined remotely via a scanning laser vibrometer (SLV) in order to detect loose bolts. A piezoelectric element (PZT) was bonded on the robot arm for excitation of surface guided waves. A spectrum analyzer generated surface waves within the 20-100 kHz range. The propagation of the waves was monitored with the SLV at the programmed grid points on the robot arm. The surface response to excitation (SuRE) method was used to calculate the spectrums of the signals, and compare the reference scan with the altered scan. Comparisons of before and after the scan showed that after loosening the bolt on the robot arm, spectrums of all the grid points changed to some extent, however, the largest changes occurred in the vicinity of the loosened bolts. The study shows that the SuRE method was capable of detecting the presence and location of loosening bolts using only one PZT element on a complex structure. There are two most important advantages of the SuRE method over the widely used impedance-based technique. The first advantage is the elimination of an expensive impedance analyzer; the second advantage is remotely monitoring capability as long as the surface is excited properly.Item A neural network based approach to estimate of power system harmonics for an induction furnace under the different load conditions(Springer Verlag, 2015) Gokozan H.; Taskin S.; Seker S.; Ekiz H.This study presents an artificial neural network based intelligent monitoring algorithm to detect of a power system harmonics. The proposed approach was tested on the current and voltage data of an induction furnace power system, which was collected by using a LabVIEW based measurement system under different load conditions. The collected data was analyzed with MATLAB program using the short-time Fourier transform and power spectral density estimation methods to find the dominant harmonics of the power system. After determination of the operational region in terms of the harmonic levels under the full-load condition, the power spectral density algorithm was used for determining the stationary intervals of the power system data. Identified harmonic frequencies were used to train the artificial neural network algorithm, which was then tested for harmonic estimation at different load conditions. Hence, the neural network topology was used as a artificial follower. Results demonstrate that harmonic state estimation of a power system can be achieved by an error variation at the output of the auto-associative neural network. © 2014, Springer-Verlag Berlin Heidelberg.Item Automated image processing system design for engineering education: The case of automatic inspection for printed circuit boards(American Society for Engineering Education, 2015) Tuncalp B.K.; Taskin S.; Turgut Y.An experimental test-bed in engineering education enhances the quality of studies and provides industrial experiences to engineer candidates. The purpose of this paper is to develop a multi-purpose test-bed for detecting defects (faults) on printed circuit boards (PCBs). Specifically, the test-bed utilizes the techniques from image processing. To achieve this aim, first a visual pattern inspection system was designed for PCBs, and second an algorithm was developed for detecting the defects related to PCB traces. The system addresses four main aspects: (i) the automatic inspection; (ii) independent angle of rotation; (iii) displaying the PCB defect area; and (iv) creating a database for defect history. Based on the results derived from several defect tests, our findings show that the system can be adapted with ease for basic industrial applications as well as a training test-bed for engineering courses such as digital image processing. © 2015 American Society for Engineering Education. All rights reserved.Item Comparison of electrical energy consumption for different material processing procedures(Carl Hanser Verlag, 2016) Gokozan H.; Tastan M.; Taskin S.; Cavdar P.S.; Cavdar U.The aim of this study is to investigate the electrical energy consumption for different material processing methods. In these experiments, ferrous powder metals, bulk iron and bulk graphite materials are used. These different materials are heated, sintered and welded by using processes of ultra-high frequency induction heating (UHFIH), ultra-high frequency induction heating sintering (UHFIHS) and ultra-high frequency induction heating welding (UHFIHW), respectively. For all experiments, 2.8 kW, 900 kHz ultra-high frequency induction heating system is used. The experiments are conducted by LabVIEWTM based measurement and control system. Finally, all data are analyzed to show the energy efficiency of each process. © Carl Hanser Verlag GmbH &Co. KG.Item Designing a real-time remote control system for undergraduate engineering and engineering technology students(American Society for Engineering Education, 2016) Yabanova I.; Taskin S.; Ekiz H.; Oǧuz Y.; Akaslan D.; Yumurtaci M.This paper explains the design of a control system intended to enhance the quality of education in engineering and engineering technology departments and considers the use of various concepts: remote-access, real-time, reconfigurable properties, and multi-user controls. Controlling the system's hardware is possible by using fuzzy logic and PID control methods to teach several engineering concepts in the field of automatic control (i.e., DC motor and temperature control). PID parameters and fuzzy logic membership rules can be modified by authorizing remote users. A Web interface was also designed as part of the system to create an opportunity for the end-users to observe real-time changes in DC motor and temperature control. Modifications to the control system's parameters also enable users to record output to their own personal computers via the Internet; this allows users from other engineering institutions to access and modify the PID and fuzzy logic membership rules for more experiences. In this way, various theoretical and practical concepts associated with the field of automatic control can be implemented without any limitations. The overall findings from this study indicate that engineering and engineering technology curricula in any institution can effectively be delivered using the Internet to overcome the limitations of distance, as remote-access experiments are becoming highly applicable anywhere and anytime.Item Placement of Dg, Cb, and Tcsc in radial distribution system for power loss minimization using back-tracking search algorithm(Springer Verlag, 2017) Fadel W.; Kilic U.; Taskin S.The back-tracking search algorithm (BSA) is a new heuristic algorithm. BSA has two especially important properties: it is not sensitive to the initial value and has a single control parameter. This study presents the BSA-based optimal sizing and placement of distributed generations (DGs), capacitor banks (CBs), and thyristor-controlled series compensator (TCSC) in a radial distribution system (RDS). These elements are integrated separately and simultaneously in RDS. The objective function is power loss. The BSA is executed on IEEE 33 bus RDS. The obtained results are compared to a genetic algorithm (GA) and other algorithms in the literature. The results demonstrate that the BSA is more efficient and has the potential to find optimal solutions with less power loss. In this paper, optimal placement and sizing of DGs, TCSC, and CBs in a RDS is solved simultaneously using BSA for the first time. © 2016, Springer-Verlag Berlin Heidelberg.Item A smart approach on collecting working condition data from home appliances under the field test(Institute of Electrical and Electronics Engineers Inc., 2017) Yildirim I.; Taskin S.This study presents management of the data that are taken from the home appliances which are in the field test process. Field test process means collecting the data from the device by sensors, the measurement from environment, then evaluation of this information. This information depends on climate, altitude, user profile etc. Major application area of this study is home appliances sets and their domestic field test process. Also, this smart approach can be applied to any system including any electrical equipment in smart grid. Only 2 different requirements should be covered. (i) Device Under Test (DUT) should work with the specialized test box to send working condition data and environmental measurements. (ii) GSM network should be alive in field test location. This study shows a new smart approach which relies on sending the field test data and environmental conditions over the GSM. The selection reason of GSM communication protocol in this study is the coverage percentage of this protocol is wider than others. © 2017 IEEE.Item The extensible analogy for supporting the aspects of smart cities: Demander and supplier(Institute of Electrical and Electronics Engineers Inc., 2017) Akaslan D.; Taskin S.; Oguz Y.The smart city is still an emerging concept due to the certain and complex requirements of individuals and community. However, there is an agreement among people that ICT will have a critical role in the sense, analysis, and integration of services in smart cities. Several models, simulations and theories have been proposed to facilitate the life of people and community in smart cities. This paper simulates a smart city to deal with the complex and certain requirements of people in smart cities in the foreseeable future. © 2017 IEEE.Item Development of measurement and analyses system to estimate test results for lead-acid starter batteries(Elsevier Ltd, 2021) Demirci O.; Taskin S.The purpose of this paper is to provide a valid and applicable measurement and analysis system for performing test durations for Lead-Acid Started Batteries. To achieve this goal, two main objectives are followed. Firstly, a measurement system is designed to conduct all of the electrical tests, then an estimation algorithm is developed for automatic analyses and reporting proceedings. All measurement parameters are monitored in the developed user interface and saved in a database. For these operations, NI LabVIEW™ based user interface is developed. Based on the analyses of test results with different battery capacities, an automated evaluation report is obtained within the frame of EN-50342-1:2015 standard for each test. In this way, the reporting proceedings of test results are conducted through the given data acquisition devices and test analysis system. Test results are estimated with precision between 90% and 98% according to the test type indicated in the standard. Accordingly, the time is saved between 57% and 84% in test durations given in the standard. © 2020Item Modeling, simulation, and experimental verification of a smart grid system(Taylor and Francis Ltd., 2022) Tozak M.; Taskin S.; Sengor I.Due to the concern over the depletion of conventional fuels and increasing environmental awareness, creating a smarter grid has gained more significance and has been alluring a wide range of industrial and academic stakeholders. One of the main features of a smart grid (SG) system is being a fully observable and controllable infrastructure from generation to the consumption of electricity among other features. A SG didactic system developed by the De Lorenzo company is utilized for this study. The didactic system is used as it serves measurements at all buses and includes diverse power grid units and devices to be used for the analysis of the system. A MATLAB/Simulink model is obtained pertaining to a SG system with generation units, transformers, transmission lines, loads, measurement devices, compensation units, and so on. Along with the modeling of each subsystem of the SG, the developed model is validated by the experiments on the real system, and also the system performance is analyzed. The SG model is validated step by step on the real test system with errors ranging from 0 to 10.03%. Hence, it has been proven that the model is able to be applied to an enlarged system and to be used for test and experimental studies of new types of equipment and educational purposes without depending on the physical system. © 2022 Taylor & Francis Group, LLC.Item Performance Analysis of Grid Forming Converters for a Didactic Smart Grid System(Institute of Electrical and Electronics Engineers Inc., 2022) Tozak M.; Taskin S.; Sengor I.Grid forming control for inverter-dominated power systems of the future is crucial as it enables more renewable penetration and provides enhanced stability. In this paper, a power system that consists of both Synchronous Machines (SM) and Grid Forming Controlled PV system is modeled and simulated in MATLAB®/Simulink®. Moreover, the real parameters of laboratory pieces of equipment in Manisa Celal Bayar University Smart Grid Laboratory (MCBU-SGLab) are used throughout the study. In addition, various Grid Forming Converter control methods such as droop control, matching control, and dispatchable virtual oscillator control are compared in terms of frequency stability under different conditions. © 2022 IEEE.