Sezai Taskin

Spectral Analysis for Current and Temperature Measurements in Power Cables

Abstract 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.

Analysis of issues for implementing e-learning: The student perspective

Integration of e-learning into campus-based institutions is a challenging issue. A number of key issues and questions clearly need to be solved and answered before any attempt for implementing e-learning is taken. The purpose of this paper is hence to investigate how to implement e-learning in the higher education institutions (HEI) associated with the subject of electricity in Turkey, considering the student perspective. For this reason, a web-based survey has been conducted to measure the extent to which the representative students in the Turkish HEI are ready for e-learning and to investigate their perspectives on issues for implementing e-learning. Two techniques were used: an online questionnaire with close- and open-ended items and semi-structured online interviews. 704 responses were analysed. At the end of the questionnaire, respondents were invited to participate in a semi-structured interview. 63 accepted the invitation, but only 33 of them actually attended the interview. Based on the findings derived from the interviews, we develop a model to illustrate what principles are needed for implementing e-learning in the respective institutions. Overall, our findings show that e-learning is perceived as a solution for resolving some issues and it brings some innovation in the respective institutions in Turkey; and that it should be integrated into campus-based education and training via the blended learning approach.

An analogy between womb and home for supporting the aspects of smart cities

A number of utilities should be delivered to householders to fulfil certain requirements via disparate infrastructures associated with production, distribution and consumption. Since the major of these utilities require enormous expenditure and bring complexity, undesired interactions and difficulty in installation, maintenance and management are always encountered. To deal with these issues, a number of models for the single-utility product have been proposed such as the blood of city and the umbilical cording vision. In this study, we propose a model by drawing an analogy between a womb and home so as to supply all services through one utility product. To form the mental picture of the analogy, the life cycle from the birth to the death are taken into consideration in four aspects: foetus as the householder, placenta as the security, umbilical cording as the networking, and amniotic fluid as the stabilizer of the indoor temperature.

A smart approach on collecting working condition data from home appliances under the field test

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.

The extensible analogy for supporting the aspects of smart cities: Demander and supplier

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.

Comparison of electrical energy consumption for different material processing procedures

Abstract 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.

Imaging multiple objects with time-reversed FDTD method at microwave range

A simulation technique is presented for imaging multiple objects in microwave region. The proposed technique is based on the time-reversed finite-difference time-domain method (FDTD-TR) in three dimensions. Using this technique, not only the locations of objects but also their detailed images can be obtained. The method is capable of imaging hidden objects with transmission as well as reflection imaging modalities in the nearfield and far-field. The proposed technique is computationally efficient due to using a much smaller data set compared to conventional FDTD-TR imaging techniques where the entire time span of the captured data is reversed. The method was validated using experimental results as well as simulations.

Analysis of vibration signals related to fuel tank in a passenger coach

In this study, the data which was taken from accelerometer located in vertical direction to fuel tank chassis of a traveler bus has been analyzed. Firstly vibration signal related to the endurance of the connection has been observed as a raw data on the time-frequency plane and then it has been passed from a critical frequency 20 Hz low pass filter and power spectrum changes have been observed. After this, critical frequency value whose peak value is about 11 Hz has been forced mechanically to the construction which consists of fuel tank has been determined. In addition, it was determined that 11 Hz emerged at about 244th second on the time scale and it has been observed that big amplitude has also been created by this frequency on the time serial.