Expectations of the students of mechatronics in the conversion of technical training faculties into technology faculties of technology

AbstractIn this study, it was aimed to determine the expectations of the students of Marmara University, Technical Training Faculty, The Department of Mechatronic Education in the conversion Technical Training Faculties into Faculties of Technology. The target population of the study was formed by the students of Marmara University, Technical Training Faculty, The Department of Mechatronic Education, and the sample was formed by one hundred students selected randomly from 1st, 2nd, 3rd and 4th grades. In the research, the relational scanning model was used. To prepare the survey questions, ten open-ended questions regarding the conversion into the Faculty of Technology were asked to the students; and then a 20-question Likert-type survey with 5 articles was prepared by analyzing these questions. The data was analyzed by the program of SPSS 15.0, and pie charts on results were provided.According to the data obtained at the end of the study, the conclusions reached were that the title problem of the students of Mechatronic Education must be solved, that Technical Training Faculties cannot benefit from Erasmus and Socrates programs as they have no equivalence in European Union, that appropriate conditions for developing common projects with industry as Mechatronic Education is mostly practical due to the nature of the department, that differences of titles and diplomas the graduates of Technical Training - Department of Mechatronic Education and the students who will graduate from Faculties of Technology during conversion must be corrected with arrangements to be made, and that the diplomas gotten must be accepted outside the country

Güç sistemlerinde ferrorezonans olayının spektral ve dalgacık analizi yöntemleriyle belirlenmesi

GÜÇ SİSTEMLERİNDE FERROREZONANS OLAYININ SPEKTRAL VE DALGACIK ANALİZİ YÖNTEMLERİYLE BELİRLENMESİ Ferrorezonans, güç sistemlerinde doyumlu transformatör, seri kapasitörler ve transformatörlerin manyetik empedansı ile ilişkili olarak ortaya çıkan bir olaydır. Ferrorezonans ile iletim ve dağıtım sistemlerinde yıkıcı etkiler gözlemlenir, hatların izolasyonu bozulabilir ve arklar oluşabilir. Ferrorezonans yüksek ve orta gerilim şebekelerinde devrenin açılıp kapanması sonucu, yüklerin aniden devre dışı kalması sonucu ve gerilim transformatörlerinin yüklerindeki simetrisizlik sebebi ile meydana gelir. Bu çalışmada; Türkiye Batı Anadolu enerji iletim hattından 380kV’luk Seydişehir-Oymapınar iletim hattı modellenerek, model üzerinde muhtemel ferrorezonans senaryoları oluşturulmuş olup, güç sisteminde ferrorezonans olayı ile otaya çıkan aşırı gerilim ve akım sinyallerinin analizleri yapılmıştır. Bu gerçek model üzerinde benzetim çalışmasından elde edilen veriler, “Zaman-Frekans” ve “Zaman-Ölçek” tanım bölgelerinde Kısa Zaman Fourier Dönüşümü (KZFD) ve Sürekli Dalgacık Dönüşümü (SDD) teknikleri vasıtasıyla analiz edilmiştir. Ayrıca Çapraz Güç Spektrumu Yoğunlukları (ÇGSY) da göz önünde bulundurularak, bunların normalizasyonu sonucunda tanımlanan “Koherens” ilişkileri kullanılmış ve güç sistemimdeki anahtarlamanın etkileri de tespit edilmiştir. Elde edilen bulgular ferrorezonans olayının tanımı ile uyumlu olup, özellikle SDD’nin analiz yöntemi olarak literatürde en çok bilinen Çok Çözünürlüklü Dalgacık Analizi (ÇÇDA) yaklaşımından daha etkin bir yaklaşım olarak kullanılabileceğini de göstermektedir. Bu anlamda da SDD’nin kullanımı yeni bir uygulamadır. İlgili literatürde frekans tanım bölgesindeki analizler, tek bir sinyal üzerine yoğunlaşmışken, bu tez çalışmasında ÇGSY’da göz önünde bulundurularak, bunların normalizasyonu sonucunda tanımlanan Koherens ilişkileri, bu alanda ilk kez kullanılarak, güç sistemimdeki anahtarlamanın etkileri de bu yolla gösterilebilmiştir. ABSTRACT DETERMINATION OF FERRORESONANCE PHENOMENON WITH SPECTRAL AND WAVELET ANALYSIS METHODS IN POWER SYSTEMS The ferroresonance is a phenomenon occurs due to magnetic impedance of saturable transformer, serial capasitors and transformers. By means of ferroresonance, distructive impacts are observed within the transmission and distribution system; line insulation may be damaged; and arcs may appear. The ferroresonance occurs as a result of swithcing on and off the circuit; of immediate deactivating the loads; and of the asymetricity within the transformer loads, within high and medium voltage systems. In this study, the Seydisehir-Oymapınar transmission line of 380kV from West-Anatolia power transmission line in Turkey has been modelled; the probable ferroresonance scenarios have been established; and over-voltage and over-current resulting from ferroresonance within the power system was analyzed. The data obtained from simulation on this real model has been analyzed by means of Short Time Fourier Transform (STFT) and Continuous Wavelet Transform (CWT) techniques within the ‘Time-Frequency’ and ‘Time-Scale’ domains. In addition, considering the Cross Power Spectral Density (CPSD), their “Coherence” relations defined as a result of their normalization were utilized and the impacts of the switching were identified. The findings are in concordance with the definition of ferroresonance phenomenon and have shown that the CWT, as an analysis method, may be used as a much more effective approach than Multi Resolution Wavelet Analysis, the most known analyzing method in the literature. In this sense, applying the CWT is a new application. In regarding literature, the analysis of frequency domain focuses on only one signal, while in this thesis study, considering the CPSD, their “Coherence” connections defined as a result of their normalization were utilized for the first time in this field and the impacts of the switching were identified in this way

Dalgacık (Wavelet) tabanlı dağıtım sistemleri koruma algoritması

The aim of foundations generating, transmission and distributing electric energy is to serve an economic and quality service to their consumers. If we are talking about quality in electric energy systems, it has been understood to serve stable and sinusoidal edge voltage in stable network frequency. Today some equipment connected to power systems and breakdown these equipments cause has become a important research topic. It is also really important not only to determine breakdowns but also to solve breakdowns in power systems. Short circuits in generator, transformer, line switch, separator, power station or isolation result in breakdown in energy transfer lines. It is very important to determine this breakdown and starting and stopping moment of breakdown for solving breakdown. In this study, it has been mentioned main types of breakdown accruing in energy transfer lines and protection methods. Techniques of Fourier and Wavelet analysis used generally signal processing have been examined. Because of the some disadvantages of Fourier Transform, subject of applying the technique of Wavelet Transform to power systems has been studied. Elektrik enerjisini üreten, ileten ve dağıtan kuruluşların görevi; kesintisiz, ekonomik ve kaliteli bir hizmeti tüketicilerine sunmaktır. Elektrik enerjisi sistemlerinde kalite söz konusu olunca, sabit şebeke frekansında; sabit ve sinüsoidal biçimli uç geriliminin sağlanması anlaşılmaktadır. Güç sistemlerine bağlanan bazı elemanlar ve bunların yol açtığı arızalar, bu arızaların tespiti ve arızaların giderilmesi önemli bir araştırma konusu haline gelmiştir. Enerji iletim hatlarında arızalar, generatör, transformatör, hat kesici, ayırıcı şalt cihazlarında kısa devrelerle ya da yalıtım sonucunda meydana gelirler. Bu arızaların tespiti, arızanın başlangıç ve bitiş anı arızanın giderilmesi için önem taşımaktadır. Bu çalışmada enerji dağıtım hatlarında meydana gelen başlıca arıza tiplerinden ve bunlara ilişkin koruma yöntemlerinden bahsedilmiştir. Geleneksel olarak işaret işlemede kullanılan Fourier ve Dalgacık teknikleri incelenmiş ve Fourier Dönüşümünün bazı dezavantajları yüzünden dalgacık dönüşümü tekniğinin güç sistemlerine uygulanması ve yorumlanması konusunda çalışılmıştır. Modelleme ve Bilgisayar Benzeşimi (Simülasyon) için ATP/EMTP programı kullanılmış buradan elde edilen sonuçlar MATLAB paket programı ve MATLAB Wavelet Toolbox kullanılarak analiz edilmiş, elde edilen sonuçlar yorumlanmıştır

Short Term Wind Speed Forecasting with ANN in Batman, Turkey

T. C. Akinci. Short Term Wind Speed Forecasting with ANN in Batman, Turkey // Electronics and Electrical Engineering. Kaunas: - Technologija, 2011. - No. 1(107). - P. 41-45. In this paper, Artificial Neural Network (ANN) technique has been used for the short term estimation of wind speed in the region of Batman, Turkey. The data were collected by the Turkish State Meteorological Service (TSMS) during ten years through a network of measurement stations located in the place of interest. Different ANN models has been developed for the short term wind speed forecasting in Batman, Turkey, using data measurements of 10 year obtained from the Turkish State Meteorological Service. First a model with ten neurons in hidden layer was chosen, the results were not sufficiently satisfactory. Other three models were developed, consisting of twenty neurons, thirty neurons and forty neurons in the hidden layers. The model of forty neurons was the best for the short term wind speed forecasting, with mean squared error and regression values of 0.311136 and 0.978094 for training respectively. The developed model for short term wind speed forecasting showed a very good accuracy to be used by the General Directorate of Electrical Power Resources Survey and Development Administration (EIE) in Batman, Turkey for the energy supply. III. 7, bibl. 14, tabl. 1 (in English; abstracts in English and Lithuanian).WOS:0002866945000102-s2.0-7996115096

Güç sistemlerinde ferrorezonans olayının spektral ve dalgacık analizi yöntemleriyle belirlenmesi

ÖZETGÜÇ SİSTEMLERİNDE FERROREZONANS OLAYININ SPEKTRAL VE DALGACIK ANALİZİ YÖNTEMLERİYLE BELİRLENMESİFerrorezonans, güç sistemlerinde doyumlu transformatör, seri kapasitörler ve transformatörlerin manyetik empedansı ile ilişkili olarak ortaya çıkan bir olaydır. Ferrorezonans ile iletim ve dağıtım sistemlerinde yıkıcı etkiler gözlemlenir, hatların izolasyonu bozulabilir ve arklar oluşabilir. Ferrorezonans yüksek ve orta gerilim şebekelerinde devrenin açılıp kapanması sonucu, yüklerin aniden devre dışı kalması sonucu ve gerilim transformatörlerinin yüklerindeki simetrisizlik sebebi ile meydana gelir. Bu çalışmada; Türkiye Batı Anadolu enerji iletim hattından 380kV’luk Seydişehir-Oymapınar iletim hattı modellenerek, model üzerinde muhtemel ferrorezonans senaryoları oluşturulmuş olup, güç sisteminde ferrorezonans olayı ile otaya çıkan aşırı gerilim ve akım sinyallerinin analizleri yapılmıştır. Bu gerçek model üzerinde benzetim çalışmasından elde edilen veriler, “Zaman-Frekans” ve “Zaman-Ölçek” tanım bölgelerinde Kısa Zaman Fourier Dönüşümü (KZFD) ve Sürekli Dalgacık Dönüşümü (SDD) teknikleri vasıtasıyla analiz edilmiştir. Ayrıca Çapraz Güç Spektrumu Yoğunlukları (ÇGSY) da göz önünde bulundurularak, bunların normalizasyonu sonucunda tanımlanan “Koherens” ilişkileri kullanılmış ve güç sistemimdeki anahtarlamanın etkileri de tespit edilmiştir. Elde edilen bulgular ferrorezonans olayının tanımı ile uyumlu olup, özellikle SDD’nin analiz yöntemi olarak literatürde en çok bilinen Çok Çözünürlüklü Dalgacık Analizi (ÇÇDA) yaklaşımından daha etkin bir yaklaşım olarak kullanılabileceğini de göstermektedir. Bu anlamda da SDD’nin kullanımı yeni bir uygulamadır.İlgili literatürde frekans tanım bölgesindeki analizler, tek bir sinyal üzerine yoğunlaşmışken, bu tez çalışmasında ÇGSY’da göz önünde bulundurularak, bunların normalizasyonu sonucunda tanımlanan Koherens ilişkileri, bu alanda ilk kez kullanılarak, güç sistemimdeki anahtarlamanın etkileri de bu yolla gösterilebilmiştir.ABSTRACTDETERMINATION OF FERRORESONANCE PHENOMENON WITH SPECTRAL AND WAVELET ANALYSIS METHODS IN POWER SYSTEMSThe ferroresonance is a phenomenon occurs due to magnetic impedance of saturable transformer, serial capasitors and transformers. By means of ferroresonance, distructive impacts are observed within the transmission and distribution system; line insulation may be damaged; and arcs may appear. The ferroresonance occurs as a result of swithcing on and off the circuit; of immediate deactivating the loads; and of the asymetricity within the transformer loads, within high and medium voltage systems. In this study, the Seydisehir-Oymapınar transmission line of 380kV from West-Anatolia power transmission line in Turkey has been modelled; the probable ferroresonance scenarios have been established; and over-voltage and over-current resulting from ferroresonance within the power system was analyzed. The data obtained from simulation on this real model has been analyzed by means of Short Time Fourier Transform (STFT) and Continuous Wavelet Transform (CWT) techniques within the ‘Time-Frequency’ and ‘Time-Scale’ domains. In addition, considering the Cross Power Spectral Density (CPSD), their “Coherence” relations defined as a result of their normalization were utilized and the impacts of the switching were identified. The findings are in concordance with the definition of ferroresonance phenomenon and have shown that the CWT, as an analysis method, may be used as a much more effective approach than Multi Resolution Wavelet Analysis, the most known analyzing method in the literature. In this sense, applying the CWT is a new application. In regarding literature, the analysis of frequency domain focuses on only one signal, while in this thesis study, considering the CPSD, their “Coherence” connections defined as a result of their normalization were utilized for the first time in this field and the impacts of the switching were identified in this way

The Defect Detection in Ceramic Materials Based on Time-Frequency Analysis by Using the Method of Impulse Noise

In this study, it was achieved by using the method of impulse noise to detect internal or surface cracks that can occur in the production of ceramic plates. Ceramic materials are often used in the industry, especially as kitchenware and in areas such as the construction sector. Many different methods are used in the quality assurance processes of ceramic materials. In this study, the impact noise method was examined. This method is a test technique that was not used in applications. The method is presented as an examination technique based on whether there is a deformation on the material according to the sound coming from it as a result of a plastic bit hammer impact on the ceramic material. The application of the study was performed on plates made of ceramic materials. Here, it was made with the same type of model plates manufactured from the same material. The noise that would occur as a result of the impact applied on a point determined on the materials to be tested has been examined by the method of time-frequency analysis. The method applied gives pretty good results for distinguishing ceramic plates in good condition from those which are cracked.WOS:0002889734000072-s2.0-7995378025

Time-frequency analysis of the current measurement by hall effect sensors for electric arc welding machine

In this study, electrical current drawn by an electric arc welding machine (EAWM) is analyzed in frequency domain as a spectral approach. A hall effect sensor is used to get the current drawn by the welter in terms of measurement component. During this study, the stages of the welding process, defined between the material and electrode, are examined. These stages are initial case; transient case and operation case respectively. In this manner, some frequency components are determined for these cases to define the welter behavior. According to the results, side band, which appeared between the 45 - 55 Hz with difference of 5 Hz at around the fundamental frequency 50 Hz, is dominant characteristic. Also, another current related property is the second harmonic of the fundamental frequency. Other band effects are also observed at the outside of the first band between 45 - 55 Hz however these effects are minor. All frequency characteristics are presented on the time-frequency plane and hence, the time-frequency relationship components are easily determined in this way.WOS:0002890800000112-s2.0-7824925492