Elektrik Teknolojisi Programı / Electronic Technologies Programme

Permanent URI for this collectionhttps://hdl.handle.net/11413/6797

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Now showing 1 - 14 of 14

Novel OFDM System Using Orthogonal Pilot Symbols with Subcarrier Index Modulation
(Bajece (İstanbul Teknik Üniversitesi), 2019) ACAR, YUSUF; Çolak, S. Aldırmaz
In this work, two new transmission schemes are proposed to increase the spectral efficiency of orthogonal frequency division multiplexing (OFDM). In practical OFDM systems, channel estimation is usually performed by employing pilot symbols which is based on inserting known symbols in the time-frequency domain. However, pilot symbol designing is one of the bottlenecks of OFDM systems limiting the increase of spectral efficiency. We apply new pilot design structures, which are use orthogonal Walsh-Hadamard codes. To increase the spectral efficiency of OFDM systems, we assign the extra bits to the index of the each orthogonal Walsh-Hadamard codes. Simulation and theoretical results show that proposed methods have better performance than conventional OFDM with higher spectral efficiency. Moreover, no more energy is spent for additional information carried in the indices compared to classical OFDM systems. As a result, proposed methods provide both spectral efficiency and energy efficiency.
Electromagnetic Waves and Material Properties
(2009) Yıldırım, Osman; Balta, Torehan
The standard impedance condition is the simplest way of simulating the material properties of a planar surface. This method is only accurate if the coating is very thin or lossy. To improve the accuracy, generalized impedance conditions can be used to simulate the material properties of a planar surface. The accurate solution of a scattering problem via planar slab depends on its thickness, the wavelength of incident wave, and material properties of the slab. Since boundary condition is local in character, accuracy decreases when the slab is illuminated at near grazing angle. Accuracy also decreases if the slab has a curved shape. To increase accuracy or provide a better simulation of the material, we have to search for alternative conditions. In this study, the Taylor series method is applied to a planar slab. This method gives reasonable solution even if slab has a curved shape. Power reflection and transmission coefficients are depicted versus different impedance and observation angles.
The Speed Control of Ac Motor With Pid By Using Siemens S7-300 Plc
(Int Scientific Conference SGEM, 14, Kilment Ohridsky BLVD, Sofia, 1797, Bulgaria, 2011) Kılıç, Ali; Tere, Mehmet Fatih; Yıldırım, Osman
S7 300 is the most widely used series in PLC Industry. Using this PLC, the control of 1024 input/output may be clone. In addition to this, using PLC system design is also possible. By peak output programming, complex factory projects and management can be fulfilled. Using PID control system which is one of the PLC controlling systems will be used to control AC motor speed. At the same time, the motor reactions will be tested by panel programming by changing PID values on computer screen. The purposes of the automatic control system, to keep the variable values in desired values for provide the system's stability.
Ultrasonic and combustion characterization of glycerol-heavy fuel oil emulsions
(Modtech Publishing House, Blvd Carol I, No 28A, Iasi, 00000, Romania, 2011) Toncu, Dana Cristina; Yıldırım, Osman
The present study aims to draw a complete characterization of glycerol-heavy fuel oil emulsions by a novel non-invasive and fast investigation technique, which helps to determine emulsion stability and physico-chemical properties through acoustic measurements application. The reflection of ultrasonic wave on emulsion droplets, particles size and volume allows analysis of phase acoustic characters, which proved good correlation with Turbiscan, especially regarding stability and structural integrity. Further combustion tests revealed a decrease in pollutants emissions proportional to glycerol fraction addition. Moreover, NO wasn't detected in combustion gas. In order to overcome toxic acrolein atmospheric release, the combustion chamber was heated to 700 degrees C with diesel oil.
The students' perceptions about their field at school of vocational sciences
(Int Scientific Conference SGEM, 14, Kilment Ohridsky Blvd, Sofia, 1797, Bulgaria, 2010) Kahvecioğlu, Habibe; Yıldırım, Osman; 48626
As it is well-known, students' vocational choice and students' personally types are very important regarding of the effectiveness of academic programs. This research aims at clarifying the relation between students' personality types and their choices by using students' perceptions. The research has been conducted on 352 students attending at School of Vocational Studies. According to the research findings, there are strong relationships between students' personality types and their choices. Based on The Five Factor Model, Inventory is an evaluation tool which is improved according to the Turkish culture. Validity and reliability analysis (dimensional self consistency cofactors vary between 0,71 and 0,88; test repeat cofactors vary between 0,83 and 0,91) show that inventory consists strong psychometric features. The results obtained from inventory were evaluated by using raw points and not norm points. In the short version of the Inventory only the five dimensions (openness for experience, responsibility consciousness, being extrovert, compatibleness, emotional balance) of the character are evaluated using total 25 attributes. The answers for the attitudes are classified in Likert scale 5. If the answers are totally suitable the grade given is 5, if totally not suitable the grade given is 1.
Internet usage among the students of vocational studies
(Int Scientific Conference SGEM, 14, Kilment Ohridsky Blvd, Sofia, 1797, Bulgaria, 2010) Duzcu, Tuba; Yıldırım, Osman
As a growing trend in the world, internet-based research occupies our daily life of people. The usage of the internet of students has increased dramatically in recent years. Internet usage has become an important part of student life. As it is well-known, internet usage includes emailing, receiving information, searching a specific topic, gaming, watching pornographic pictures, shopping, downloading, communicating, and having new friends and so on. The aim of this research is to examine the relationship between personality and internet usage of the students of Vocational school in a few of private Universities in Istanbul, Turkey. There is a significant correlation between the student' personality and the student' internet usage. Adjective Check List (ACL) items consist of adjectives which are words and/or phrases used for daily descriptions in Turkish Language. The scale composed of 25 items is examined for psychometric properties. In this research, Internet Addiction Inventory and ACL were conducted at the same time to a sample of 240 students of School of Vocational Studies.
Electromagnetic Crane Design Considerations in Mining
(Stef92 Technology Ltd, 1 Andrey Lyapchev Blvd, Sofia, 1797, Bulgaria, 2012-06) Yıldırım, Osman; Bahadır, Ali; 13907; 29284
This research aimed at designing electromagnetic crane used for carrying ferromagnetic material from one place to another place without creating damage and by saving employement. Electromagnetic Crane circuit design, according to the weight of ferromagnetic material and the appropriate magnetic field calculation will ensure electromagnetic shooting. The geometric shape of the material (rectangular prisms, rods, cylinders, etc.) so that it is appropriate and the shooting power of the magnetic coil was calculated. Capture the power of electronic power train is designed to provide.
Electromagnetic Beam Scattering From Planar Surfaces
(Int Scientific Conference Sgem, 14, Kilment Ohridsky Blvd, Sofia, 1797, Bulgaria, 2011) Yıldırım, Osman; Tere, Mehmet Fatih; Kılıç, Ali; TR13907
Nondestructive techniques by using electromagnetic waves in many disciplines such as agriculture, engineering geology, material sciences and so on are very important regarding predictions. As it is well-known, material properties can be determined by using electromagnetic waves. The scattering of electromagnetic waves due to physical and geometrical discontinuity is creating surface waves which are still dominant in prediction of material properties. A dielectric sheet on the ground plane will act as a guiding structure for surface waves. Matching the magnetic and electric field components across the air-dielectric boundary gives surface wave modes. In this research, beam wave scattering from planar surfaces is analyzed by including a comparison to the electromagnetic waves.
Electromagnetic Properties Of Materials And Some Prediction Remarks
(Incdtp-Icpi, Ion Minulescu 93, 3Rd Sector, Bucharest, 031215, Romania, 2010) Yıldırım, Osman; TR13907
Nondestructive techniques by using electromagnetic waves in many disciplines such as agriculture, engineering geology, material sciences and so on, are very important regarding predictions. As it is well-known, material properties can be determined by using electromagnetic waves. The scattering of electromagnetic waves due to physical and geometrical discontinuity is creating surface waves which are still dominant in prediction of material properties. A dielectric sheet on the ground plane will act as a guiding structure for surface waves. Matching the magnetic and electric field components across the air-dielectric boundary gives surface wave modes. Surface waves and related currents may be analyzed by using Wiener-Hopf technique. One of the components of the scattered field is the surface wave, propagating along the air-ground interface. Wiener-Hopf showed that a certain singular integral equation could be solved exactly using the theory of Complex Fourier transforms and functions of a complex variable. This method of solution is known as the Wiener-Hopf technique. In order to explain electromagnetic wave scattering, we have to find the solution of Maxwel equations by using boundary or mixed boundary conditions. Wiener-Hopf technique is very important tool in the solution of scattering problems having special geometrical structures. Wiener-Hopf geometries (half plane, cylinder, strip geometry, step discontinuity, double step discontinuity or strip with thickness) and related solution methods under Wiener-Hopf analysis have been studied.
The Impact Of Social Intelligence On Academic Achievement Of Students Studying Media
(Int Scientific Conference Sgem, 14, Kilment Ohridsky Blvd, Sofia, 1797, Bulgaria, 2010) Tanakıncı, Orhan; Yıldırım, Osman; TR227408; TR13907
The importance of understanding Social Intelligence (SI) skills has gravitated form the business management to training activities. Social intelligence skills that students have affect the academic performance of the students. This study aimed at exploring the relationship between one of those well-known concepts, job satisfaction, and emotional intelligence. To this end, a research has been conducted on the students who are attending at school of vocational studies (n=150) of a private university in Istanbul. In the research, RSA-scale (Hjemdal, Friborg, Martinussen, and Rosenvinge) was used to assess students' social intelligence. According to the results, a weak relationship (r<0,40) was revealed between social intelligence and academic achievement. On the other hand, one of the five dimensions of social intelligence was found to be strongly related (r>0,40) to the academic achievement.
Social Skills Via Emotional intelligence: Language Learning
(Int Scientific Conference Sgem, 14, Kilment Ohridsky Blvd, Sofia, 1797, Bulgaria, 2010) Yıldırım, Osman; TR13907
The aim of this essay to draw an outline of the effect of various types of intelligence, paying particular attention to the concept of so called "Emotional Intelligence" with a language teacher's perspective. Throughout the essay it is aimed to create an awareness of different intelligence capacity of each individual learner in an ideal language teaching environment. While doing this literature on the area has been scanned and case studies have been performed on learners of various cultural and geographical backgrounds. In literature, many quantitative findings indicate that there is a significant relationship between academic achievement and emotional intelligence skills. The importance of understanding Emotional intelligence (El) skills and social intelligence (SI) has gravitated form the business management to training activities. This study aimed at exploring the impact of social intelligence and emotional intelligence on the language learning. To this end, a research has been conducted on the students of vocational school (n=280) of two private vocational schools in Istanbul. In the research, participants emotional intelligence was assessed by the Emotional Competence Inventory (ECI, 2nd Version) developed by Boyatzis and Goleman and the Resilience Scale for Adults (RSA-scale) proposed by Hjemdal, Friborg, Martinussen, and Rosenvinge. According to the results, a strong relationship was revealed among emotional intelligence, social intelligence and language learning.
Scattering Of Electromagnetic Waves And Prediction Remarks Regarding Mining
(Int Scientific Conference Sgem, 14, Kilment Ohridsky Blvd, Sofia, 1797, Bulgaria, 2010) Yıldırım, Osman; TR13907
A number of scattering and diffraction problems concerning semi infinite wave guides have been solved by many authors and for many years. Theoretical analysis of electromagnetic wave scattering and diffraction problems has been investigated extensively with regard to a number of scatterers which have physical and geometrical discontinuities. As is well-known, Sommerfeld introduced the exact solutions to the diffraction by a wedge by defining the idea of multiple-valued functions. His method is known as the Sommerfeld theory of diffraction which is commonly defined for diffraction by Wedge-Shaped obstacles. Wiener-Hopf showed that a certain singular integral equation could be solved exactly using the theory of Complex Fourier transforms and functions of a complex variable. This method of solution is known as the Wiener-Hopf technique. Multiple diffraction of electromagnetic waves due to physical and geometrical discontinuity is creating surface waves which are still dominant in communication phenomena. Surface waves and related currents are analyzed by using Wiener-Hopf technique in detail.
Learning model in school of vocational studies
(INT SCIENTIFIC CONFERENCE SGEM, 14, KILMENT OHRIDSKY BLVD, SOFIA, 1797, BULGARIA, 2008) Bal, Pervin; Yıldırım, Osman; TR174792; TR13907
In this research, it is aimed to determine which individual and environmental characteristics affecting training. Instead of both types of evaluation models, to be proactive, the evaluation of training mentioned in this research is focused on how training affects individuals. To this end, in this thesis the factors affecting to the training effectiveness were examined in regard of trainee perspectives. According to the research results, it is revealed that mostly related to the training effectiveness are respectively: trainer's consideration of employees' learning styles, employees motivation to attend the training, employee's organizational affective commitment and employee's belief that the training will add value to his/her career.
Academic Achievement and Psychologial Stress:Evidence From Turkey
(INT SCIENTIFIC CONFERENCE SGEM, 14, KILMENT OHRIDSKY BLVD, SOFIA, 1797, BULGARIA, 2008) Dede, Nazan; Özer, Aslıhan; Yıldırım, Osman; TR13907
The topics of stress and academic achievement are becoming increasingly interesting to educational institutions and their members. The aim of this research is to examine the relationship between personality and academic achievement of the Students of Vocational school in a private University in Istanbul, Turkey. There is a significant correlation between the students' personalities which are depicted via adjective checklist and the students' stress level assessed by Abidin's Stress Scale. Adjective Check List (ACL) items consist of adjectives which are words and/or phrases used for description in daily life in Turkish Language. The original ACL was built by 230 items. By using factor analysis, 230 items were reduced to 100 items. The scale composed of 100 items is examined for psychometric properties and internal consistency. Abidin's Stress Scale and ACL are conducted in the same time to a sample of 425 Students of School of Vocational Studies. Stress level and personality correlates of ACL are of interest on two Counts. First, in using the ACL it is important to know what variables may be confounded with mood. Second, there exist correlations between personality and mood.

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