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Wireless body sensor networks have drawn significant attention for providing out-of-hospital diagnosis and remote abnormality monitoring, which are vitally important for millions of people suffering from chronic diseases. Batteries powering these sensor networks hurt their mobility and longevity due to their bulkiness and down-time during charging or replacement. Therefore, this study focuses on thermoelectric energy harvesting from body heat, and targets eventual replacement of batteries by generating power levels above 1 mW using a fully integrated interface circuit component. The 180nm standard CMOS circuit, designed using Cadence IC design suite, contains the first optimized implementation of a previously developed quadrupling oscillator concept, a charge-pump based DC-DC converter, and a maximum power point tracking circuitry. Simulations using the electrical model of a commercial TEG module show that the DC-DC converter is capable of up to 1.5 mW output power, and 2 V output voltage, with 37% interface circuit efficiency when the TEG voltage is 500 mV. Minimum input voltage for the converter startup is found as 92 mV in the post-layout simulations. The interface circuit simulations with MPPT achieve 1.24 mW output power and 1.5 V output voltage for the TEG voltage of 500 mV. In the corresponding circumstance, the interface circuit efficiency is recorded as %20. The optimized interface circuit can be utilized to power up WBSN and enables batteryless sensor network operations.-M.S. - Master of Scienc

Space-time fractional heat equation’s solutions with fractional inner product

The main goal in this study is to determine the analytic solution of onedimensional initial boundary value problem including sequential space-time fractional differential equation with boundary conditions in Neumann sense. The solution of the space-time fractional diffusion problem is accomplished in series form by employing the separation of variables method. To obtain coefficients in the Fourier series is utilized a fractional inner product. The obtained results are supported by an illustrative example. Moreover, it is observed that the implementation of the method is straightforward and smooth.Publisher's Versio

NUMERICAL SOLUTIONS OF NONLINEAR FRACTIONAL DIFFERENTIAL EQUATIONS VIA LAPLACE TRANSFORM

In this study, solutions of time-space fractional partial differential equations(FPDEs) are obtained by utilizing the Shehu transform iterative method. The utilityof the technique is shown by getting numerical solutions to a large number of FPDEs

Numerical solutions of nonlinear system of fractional differential equations via a new integral transform

In this study, solutions of system of time-space fractional partial differential equations (FPDEs) are obtained by utilizing the Shehu transform iterative method. The utility of the technique is shown by getting numerical solutions to a large number of system of FPDEs.Publisher's Versio

Social media and hidden curriculum: What do teacher-student interactions teach students?

The aim of this study is to examine the views of the students about the learning outcomes of teacher-student interactions on social media within the context of hidden curriculum. To this end, a quantitative associational research design was used in this study. Within the scope of the research, 2046 students attending to the middle schools in Kahramanmaraş province were selected into the sample. The data of the study were collected using “Hidden curriculum on social media scale” which has a four-factor structure consisting of 16 items developed by the researchers. The results of the analysis from the hidden curriculum perspective revealed that as a result of interactions between the teacher and the student on social media, students learn some rules and values, know better about their teachers, restrain themselves from sharing and communicating about certain topics, and gain confidence in communication. Furthermore, a statistically significant difference was found in favor of male students in terms of learning to restraint and gaining confidence in communication, whereas no significant difference was observed in terms of learning rules and values, and knowing better about teachers. With regard to grade level, the learning outcomes of especially the 5th graders through hidden curriculum on social media were found to be significantly more than those of other students in upper classes of middle schools. However, all the statistically significant differences were found to have small effect sizes. It was also found that the daily time students spend on social media and the number of teachers added as friends to their accounts were significant predictors of students' their learning outcomes within the scope of hidden curriculum.The aim of this study is to examine the views of the students about the learning outcomes of teacher-student interactions on social media within the context of hidden curriculum. To this end, a quantitative associational research design was used in this study. Within the scope of the research, 2046 students attending to the middle schools in Kahramanmaraş province were selected into the sample. The data of the study were collected using “Hidden curriculum on social media scale” which has a four-factor structure consisting of 16 items developed by the researchers. The results of the analysis from the hidden curriculum perspective revealed that as a result of interactions between the teacher and the student on social media, students learn some rules and values, know better about their teachers, restrain themselves from sharing and communicating about certain topics, and gain confidence in communication. Furthermore, a statistically significant difference was found in favor of male students in terms of learning to restraint and gaining confidence in communication, whereas no significant difference was observed in terms of learning rules and values, and knowing better about teachers. With regard to grade level, the learning outcomes of especially the 5th graders through hidden curriculum on social media were found to be significantly more than those of other students in upper classes of middle schools. However, all the statistically significant differences were found to have small effect sizes. It was also found that the daily time students spend on social media and the number of teachers added as friends to their accounts were significant predictors of students' their learning outcomes within the scope of hidden curriculum

THE ANALYTIC SOLUTION OF INITIAL BOUNDARY VALUE PROBLEM INCLUDING TIME FRACTIONAL DIFFUSION EQUATION

The motivation of this study is to determine the analytic solution of initial boundary value problem including time fractional differential equation with Neumann boundary conditions in one dimension. By making use of seperation of variables, the solution is constructed in the form of a Fourier series with respect to the eigenfunctions of a corresponding Sturm-Liouville eigenvalue problem

Effects of the ARA transform method for time fractional problems

The aim of this study is to establish the solutions of time fractional mathematical problems with the aid of new integral transforms called the ARA transform. The fractional derivative is taken in the sense of Liouville-Caputo derivative. The fractional partial differential equations are reduced into ordinary differential equations. Later solving this fractional equation and applying inverse the ARA transform, the solution is acquired. The implementation of this transform for fractional differential equations is very similar to the implementation of the Laplace transform. However, the ARA transform allows us to take the integral transform of some functions for which we can not take the Laplace transform. The illustrated examples justify that the implementation and efficiency of this method are better than any other integral transforms to tackle time fractional differential equations (TFDEs)

Study of test equating on the common item non-equivalent group designOrtak maddeli denk olmayan gruplar desenine ilişkin test eşitleme çalışması

This research aims at testing the statistical equivalence of different forms of a test which are administered at the same time. For our purposes, an equating design with shared items was used for non-equivalent groups. Non-equivalent groups design with common items is used for problems that might arise in relation to the reliability and implementation of tests in which different forms are applied. The data set of the research was obtained from   responses   given by students participating in the PISA 2009 application within Turkey’s sample. The data collected from the 761 students of 15 age group who had answered the 3rd and 10th booklets of the science studies literacy test were analyzed through Tucker Linear equating, Levine linear equating, frequency prediction and Braun-Holland linear equating methods. The weighted mean error squares averages indices that were obtained through equating procedures were 0.046 for the Tucker- linear equating, 0.072 for the Levine- linear equating, 0.049 for frequency prediction, and 0.034 for the Braun-Holland linear equating. It was observed based on the WMSE coefficient that the Braun-Holland linear equating method was the most appropriate for the equating of booklets 3 and 10 in the PISA 2009 Science Studies sub-test ÖzetBu araştırmanın amacı aynı anda uygulanan bir teste ait farklı formların istatistiksel eşitliğini sınamaktır. Bu amaç için denk olmayan gruplar için ortak maddeli eşitleme deseni kullanılmıştır.  Ortak maddeli denk olmayan gruplarda ortak test deseni; farklı formların uygulandığı testlerin güvenliği ve uygulamasıyla ilgili meydana gelebilecek problemlerden dolayı kullanılmaktadır. Araştırmanın veri setini, PISA 2009 uygulamasına Türkiye örnekleminde katılmış olan öğrencilerin vermiş oldukları cevaplar oluşturmaktadırlar. Fen Bilimleri okuryazarlık testinin 3. ve 10. kitapçıklarını cevaplayan 15-yaş grubu 761 öğrenciden elde edilen veriler Tucker doğrusal eşitleme, Levine doğrusal eşitleme, frekans tahmin ve Braun-Holland doğrusal eşitleme yöntemlerine göre analiz edilmiştir. Eşitleme işlemleri sonucunda elde edilen ağırlıklandırılmış hata kareleri ortalaması indeksleri ise Tucker-Doğrusal Eşitleme için 0,046; Levine-Doğrusal Eşitleme için 0,072; Frekans Tahmin Eşit Yüzdelikli eşitleme için 0,049 ve Braun-Holland Doğrusal Eşitleme için ise 0,034 olarak bulunmuştur. Ağırlıklandırılmış hata kareleri ortalaması katsayılarına göre Braun-Holland Doğrusal Eşitleme yönteminin PISA 2009 Fen Bilimleri alttestindeki 3 ve 10 numaralı kitapçıkların eşitlenmesi için en uygun yöntem olduğu görülmektedir

SOLUTIONS FOR THE FRACTIONAL MATHEMATICAL MODELS OF DIFFUSION PROCESS

In this research we present two new approaches with Laplace transformation to form the truncated solution of space-time fractional differential equations (STFDE) with mixed boundary conditions. Since order of the fractional derivative of time derivative is taken between zero and one we have a sub-diffusive differential equation. First, we reduce STFDE into either a time or a space fractional differential equation which are easier to deal with. At the second step the Laplace transformation is applied to the reduced problem to obtain truncated solution. At the final step using the inverse transformations, we get the truncated solution of the problem we consider it. Presented examples illustrate the applicability and power of the approaches, used in this study

An analysis of the differential item function through Mantel-Haenszel, SIBTEST and Logistic Regression MethodsMantel-Haenszel, SIBTEST ve Lojistik Regresyon Yöntemleri ile değişen madde fonksiyonunu analizi

This study performs a Differential Item Function (DIF) analysis in terms of gender and culture on the items available in the PISA 2009 mathematics literacy sub-test. The DIF analyses were done through the Mantel Haenszel, Logistic Regression and the SIBTEST methods. The data for the gender variable were collected from the responses given by 332 students to the items in the mathematics literacy sub-test during the administration of the 5th booklet in the PISA 2009 application whereas the data for the culture variable were collected through the application of the 5th booklet in Turkey, Germany, Finland and the United States in the PISA 2009 application. As a result of DIF analysis according to gender, 4 items carried out in favor of men, only one item can be said to be advantageous in favor of girls. As a result of DIF analysis according to culture, 16 items for Turkish and German students, 14 items for Turkish and Finn students, 18 items for Turkish and United States students were determined.  ÖzetBu çalışmada, PISA 2009 uygulaması Matematik okuryazarlığı alttestinde, cinsiyete ve kültüre göre değişen madde fonksiyonu (DMF) içeren madde bulunup bulunmadığı incelenmiştir. DMF analizleri Mantel Haenszel, Lojistik Regresyon ve SIBTEST yöntemleriyle gerçekleştirilmiştir. Çalışmanın veri setini, cinsiyet değişkeni için PISA 2009 uygulamasında Türkiye’de 5. kitapçığındaki matematik okuryazarlığı alt testindeki maddelere 332 öğrencinin verdikleri cevaplar, kültür değişkeni için ise PISA 2009 uygulamasında Türkiye, Almanya, Finlandiya ve ABD’deki öğrencilerin 5. kitaptaki matematik testine verdikleri cevaplar oluşturmaktadır. Cinsiyet değişkenine göre 5 maddenin 4’ü erkekler lehine, bir maddenin kızlar lehine avantajlı olduğu söylenebilir. DMF analizi sonucunda Türkiye ile Almanya’dan katılan öğrencilerden elde edilen veri setlerinde 16, Türkiye ile Finlandiya’dan katılan öğrencilerden elde edilen veri setlerinde 14, Türkiye ile ABD’den katılan öğrencilerden elde edilen veri setlerinde 18 maddede DMF bulunduğu görülmüştür.