The generalize and extend Sobolev's result relative to the wave equation with the function velocity

Bu tezde fonksiyon katsayılı hiperbolik denklemler için başlangıç değer problemi çalışılmıştır. Bu problemlerin çözümleri tekil çekirdeğe sahip, Volterra integral denklemini sağladığı ispatlanmıştır. Bu indirgemede gezgin zaman fonksiyonu ve Sobolev fonksiyonu önemli rol oynar. Asimtotik koşulu ile gezgin zaman fonksiyonu Eikonel denklemin bir çözümüdür. Sobolev fonksiyonu taşıyıcı (transport) denklemin çözümüdür. Bu indirgemede taşıyıcı denklem yeniden yapılandırılmıştır. İntegral denklemler yaklaşık ardışıklar yöntemiyle ispatlanmıştır. Bu tezde Sobolev’in fonksiyon hızlı dalga denklemiyle ilgili sonuçların bir genellemesi yapılmıştır.Initial value problems for hyperbolic equations with function coefficients are considered in this thesis. It was proved that the solutions of these problems satisfy Volterra integral equations with singular kernels. The travel time function and so-called Sobolev’s function play very important role in the procedure of this reduction. The travel time function is a solution of the eikonal equation with asymptotic condition and Sobolev function is solution of the special transport equation with the asymtotic condition of the form This transport equation is constructed in the process of the equation. These Volterra integral equations were solved by the successive approximations. The result of the thesis generalize Sobolev’s result relative to the wave equation with the function velocity

The Investigation on Physical Education Teacher Candidate’s Resilience, Tenacity and Motivation Levels

The main purpose of this study is to examine possible relationships between resilience, tenacity and motivation of physical education teacher candidates. In addition, resilience, tenacity and motivation levels were examined according to class and gender levels. Participants of the study are 154 PE students in Ağrı province. There are 50 female participants and 104 male students. The Resilience Scale adapted to Turkish by Sarıçam et al. (2012). The Tenacity Scale-Short Form adapted to Turkish by Sarıçam et al. (2016) Stability Scale and Personal Information Form were used. To analyze the data, t test, ANOVA, Pearson moment product correlation analysis and multiple regression analysis were used. 99% p <.01 was taken as confidence interval in the study. According to research findings, there are statistically significant relationships in positive direction among the resilience, tenacity and motivation in the candidates of physical education teachers. When the resilience increases, tenacity and motivation levels also increase. According to gender and class level, resilience, tenacity and motivational stability do not differ statistically. The study can be expanded by adding different sections and classes

Predicting NOx emissions in diesel engines via sigmoid NARX models using a new experiment design for combustion identification

Diesel engines are still widely used in heavy-duty engine industry because of their high energy conversion efficiency. In recent decades, governmental institutions limit the maximum acceptable hazardous emissions of diesel engines by stringent international regulations, which enforces engine manufacturers to find a solution for reducing the emissions while keeping the power requirements. A reliable model of the diesel engine combustion process can be quite useful to search for the best engine operating conditions. In this study, nonlinear modeling of a heavy-duty diesel engine NOx emission formation is presented. As a new experiment design, air-path and fuel-path input channels were excited by chirp signals where the frequency profile of each channel is different in terms of the number and the direction of the sweeps. This method is proposed as an alternative to the steady-state experiment design based modeling approach to substantially reduce testing time and improve modeling accuracy in transient operating conditions. Sigmoid based nonlinear autoregressive with exogenous input (NARX) model is employed to predict NOx emissions with given input set under both steady-state and transient cycles. Models for different values of parameters are generated to analyze the sensitivity to parameter changes and a parameter selection method using an easy-to-interpret map is proposed to find the best modeling parameters. Experimental results show that the steady-state and the transient validation accuracies for the majority of the obtained models are higher than 80% and 70%, respectively

Driver evaluation in heavy duty vehicles based on acceleration and braking behaviors

In this paper, we present a real-time driver evalua-tion system for heavy-duty vehicles by focusing on the classifica-tion of risky acceleration and braking behaviors. We utilize animproved version of our previous Long Short Memory (LSTM)based acceleration behavior model [10] to evaluate varyingacceleration behaviors of a truck driver in small time periods.This model continuously classifies a driver as one of six driverclasses with specified longitudinal-lateral aggression levels, usingdriving signals as time-series inputs. The driver gets accelerationscore updates based on assigned classes and the geometry ofdriven road sections. To evaluate the braking behaviors of atruck driver, we propose a braking behavior model, which usesa novel approach to analyze deceleration patterns formed duringbrake operations. The braking score of a driver is updated foreach brake event based on the pattern, magnitude, and frequencyevaluations. The proposed driver evaluation system has achievedsignificant results in both the classification and evaluation ofacceleration and braking behaviors

Estimating soot emission in diesel engines using gated recurrent unit networks

In this paper, a new data-driven modeling of a diesel engine soot emission formation using gated recurrent unit (GRU) networks is proposed. Different from the traditional time series prediction methods such as nonlinear autoregressive with exogenous input (NARX) approach, GRU structure does not require the determination of the pure time delay between the inputs and the output, and the number of regressors does not have to be chosen beforehand. Gates in a GRU network enable to capture such dependencies on the past input values without any prior knowledge. As a design of experiment, 30 different points in engine speed - injected fuel quantity plane are determined and the rest of the input channels, i.e., rail pressure, main start of injection, equivalence ratio, and intake oxygen concentration are excited with chirp signals in the intended regions of operation. Experimental results show that the prediction performances of GRU based soot models are quite satisfactory with 77% training and 57% validation fit accuracies and normalized root mean square error (NRMSE) values are less than 0.038 and 0.069, respectively. GRU soot models surpass the traditional NARX based soot models in both steady-state and transient cycles

PLACING A THREADED PLUG IN THE HOLE OF A LOCKING PLATE AT THE FRACTURE LEVEL CAN INCREASE THE RESISTANCE OF THE PLATE:A BIOMECHANICAL STUDY

Objectives: This study aimed to evaluate whether placing a threaded plug in the hole of a locking plate at the fracture level is beneficial for increasing the resistance of the plate. Methods: This experimental study analyzed load and compression forces in sheep tibia bone models. The following groups were assessed: Group 1 (n = 4), control bone samples; Group 2 (n = 4), samples of screw plate fixation without threaded plug in the hole at the fracture level; and Group 3 (n = 4), samples of screw plate fixation with a threaded plug in the hole at the fracture level. Elastic force, bending moment, elastic compression, and rigidity were evaluated using a three-point bending test. Results: Group 1 showed the greatest elastic force and the least amount of compression. The rigidity and elastic force were better in Group 3 than in Group 2. The mean elastic force in Group 3 was 22.4% of that in Group 1, whereas the mean elastic force in Group 2 was 19% of that in Group 1. Rigidity in Group 3 was 24.7% of that in Group 1, whereas rigidity in Group 2 was 18.3% of that in Group 1. Improved results were obtained in Group 3 when compared with Group 2. Conclusions: Our results suggest that placing a threaded plug in the hole of the plate at the fracture level provides additional rigidity and stability by improving resistance to loading forces, but the differences were not statistically significant

The effects of physical activity cards on teacher behaviours in elementary physical education classes Fiziksel etkinlik kartları uygulamasının ilköğretim beden eğitimi derslerindeki öğretmen davranışları üzerine etkisi

The aims of this study were to investigate the effects of usage of ‘’the physical activity cards’ on teacher behaviors to maintain students as physically active in Physical Education classes. Total 384 students (first, second and third grades elementary school students) and 24 teachers from 7 elementary schools from Mugla center were observed by SOFIT (System for Observing Fitness Instruction Time) is a direct systematic observation method. Pretest and posttest results of variables were analyzed by using Paired T test.It was found that physical activity cards have an effect on teachers’ behavior. Teachers motivated students to exercise in their class and they gave much lesser free time and they engaged much lesser other things during lesson time.As a result, the physical activity cards are useful materials for development of skill in physical education lessons. There will be positive improvements in physical activity levels, lesson context and teacher behavior if some factors like appropriate group size, enough materials and efficient class management of teachers would be make better. Özet Bu çalışmanın amacı Fiziksel Aktivite Kartları uygulamasının ilköğretim öğrencilerinin derslerde daha aktif olmaları açısından öğretmen davranışlarına etkisini araştırmaktır. Bu amaçla Muğla İli merkez ilçeden seçilen 7 okul, 24 öğretmen ve birinci, ikinci ve üçüncü sınıflarda okuyan 384 öğrenci direkt sistematik gözlem aracı olan SOFIT ile gözlenmiştir. Deney ve kontrol grubundaki ön ve son gözlemler arasındaki fark eşleştirilmiş (Paired) t testi ile analiz edilmiştir. Elde edilen bulgulara göre öğretmenler fiziksel aktivite kartlarıyla işledikleri derslerde öğrencileri daha çok “egzersize teşvik” etmişlerdir. Bu olumlu gelişmeye paralel olarak öğrencileri daha az “serbest” bırakmışlar, daha az ders dışı işlerle (diğer Sonuç olarak, fiziksel aktivite kartları beden eğitimi derslerinde “beceri” gelişimi için oldukça kullanılır bir materyaldir. Derslerde uygun grup sayıları, yeterli sayıda malzeme ve öğretmenin sınıfı iyi yönetmesi gibi etkenler iyileştirilirse öğretmen davranışlarında olumlu gelişmeler söz konusu olacaktır

Diesel engine NOx emission modeling using a new experiment design and reduced set of regressors

n this paper, NOx emissions from a diesel engine are modeled with nonlinear autoregressive with exogenous input (NARX) model. Airpath and fuelpath channels are excited by chirp signals where the frequency profile of each channel is generated by increasing the number of sweeps. Past values of the output are employed only in linear prediction with all input regressors, and the most significant input regressors are selected for the nonlinear prediction by orthogonal least square (OLS) algorithm and error reduction ratio. Experimental results show that NOx emissions can be modeled with high validation performance and models obtained using a reduced set of regressors perform better in terms of stability and robustness