Clinical Relevance of Choroidal Thickness in Obese and Healthy Children: A Machine Learning Study

Objectives:To analyze the effect of macular choroidal thickness (MCT) and peripapillary choroidal thickness (PPCT) on the classification of obese and healthy children by comparing the performance of the random forest (RF), support vector machine (SVM), and multilayer perceptrons (MLP) algorithms.Materials and Methods:Fifty-nine obese children and 35 healthy children aged 6 to 15 years were studied in this prospective comparative study using optical coherence tomography. MCT and PPCT were measured at distances of 500 μm, 1,000 μm, and 1,500 μm from the fovea and optic disc. Three different feature selection algorithms were used to determine the most prominent features of all extracted features. The classification efficiency of the extracted features was analyzed using the RF, SVM, and MLP algorithms, demonstrating their efficacy for distinguishing obese from healthy children. The precision and reliability of measurements were assessed using kappa analysis.Results:The correlation feature selection algorithm produced the most successful classification results among the different feature selection methods. The most prominent features for distinguishing the obese and healthy groups from each other were PPCT temporal 500 μm, PPCT temporal 1,500 μm, PPCT nasal 1,500 μm, PPCT inferior 1,500 μm, and subfoveal MCT. The classification rates for the RF, SVM, and MLP algorithms were 98.6%, 96.8%, and 89%, respectively.Conclusion:Obesity has an effect on the choroidal thicknesses of children, particularly in the subfoveal region and the outer semi-circle at 1,500 μm from the optic disc head. Both the RF and SVM algorithms are effective and accurate at classifying obese and healthy children

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

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

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

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

The examination of the functionality of educational clubs in secondary school according to the opinions of principals, teachers and the students.

TEZ9552Tez (Yüksek Lisans) -- Çukurova Üniversitesi, Adana, 2014.Kaynakça (s. 217-223) var.xxi, 251 s. : tablo ; 29 cm.Bu araştırmanın temel amacı; ortaöğretimdeki eğitsel kulüp çalışmalarının işlevselliğini yönetici, kulüp danışmanı ve öğrenci görüşleri doğrultusunda incelemektir. Bu genel amaç doğrultusunda katılımcıların eğitsel kulüplerin gerekliliğine olan inancına, öğrencilere sağladığı faydalara, kulüplerin uygulama sürecinde yaşanan problemlere ve daha etkin hale getirilmesi için yapılması gerekenlere ilişkin görüşlerine başvurulmuştur. Araştırmanın yöntemi, nicel ve nitel yöntemlerin birlikte kullanıldığı karma yöntem araştırmasıdır. Araştırmanın nicel boyutunu; Adana ili merkez ilçelerinde 2012 – 2013 yılında okul türü farklı ortaöğretim kurumlarında (Fen Lisesi, Anadolu Lisesi, İmam-Hatip Lisesi, Endüstri Meslek Lisesi ve Genel Lisesi) öğrenim gören 469 öğrenci oluşturmuştur. Ankete verilen cevapların ve demografik değişkenlerin yüzde ve frekansları çıkarılmıştır. Ayrıca demografik değişkenlerle anket maddelerine verilen cevapların çaprazlaması yapılmıştır. Elde edilen veriler bilgisayarda SPSS for Windows versiyon 15.0 yardımıyla istatistiksel teknikler kullanılarak çözümlenmiş ve yorumlanmıştır. Katılımcıların görüşlerini derinlemesine ve çok boyutlu olarak incelemek amacıyla veri toplama sürecinde görüşme yöntemi kullanılmıştır. Görüşme; Adana ili merkez ilçelerindeki ortaöğretim kurumlarında görev yapan 14 öğretmen ve bu kurumlarda görev yapan 6 yönetici ile yapılmıştır. Verilerin toplanmasında araştırmacı tarafından hazırlanan yarı–yapılandırılmış görüşme formu kullanılmış, verilerin analizinde ise içerik analizi tekniğinden yararlanılmıştır. Öğrencilerin %31’nin üyesi oldukları eğitsel kulüplerin herhangi bir faaliyetinde yer almadığı belirlenmiştir. Öğrencilerin çoğunluğu kulüplerin gerekli ve kendilerine birçok yararı olduğuna katılmaktadır. Buna karşın olumsuz görüş bildiren öğrencilerin sayısının da azımsanmayacak düzeyde olduğu görülmüştür. Araştırma sonuçları okul türü değişkenine göre değerlendirildiğinde anket maddelerine verilen cevapların farklılaştığı görülmüştür. Anadolu Lisesi öğrencilerinin eğitsel kulüp çalışmalarının gerekliliğine ve sağladığı faydalara olan inancı diğer liselere (Genel Lise, Meslek ve İmam – Hatip Lisesi) göre daha yüksek düzeydedir. Buna karşın Fen Lisesi öğrencilerinin eğitsel kulüplerin gerekliliği ve kendilerine sağladığı faydalara olan inancı en düşük düzeydedir. Eğitsel kulüplerin daha işlevsel hale getirilmesine yönelik çalışmaların yapılması ve kulüp uygulamalarının önündeki engellerin kaldırılması gerektiğine öğrencilerin büyük çoğunluğu katılmaktadır. Ayrıca araştırma sonuçları cinsiyet değişkenine göre değerlendirildiğinde anket maddelerine verilen cevapların birbirine yakın değerlerde olduğu görülmektedir.The main purpose of this study is to examine the functionality of educational clubs in secondary schools from the point of principal, teacher and the students. In line with the general objectives to the belief in the necessity of educational clubs, the benefits for the students have been consulted about what needs to be done in the implementation process to make the clubs more effective. The method of the study is the mixed method, used in conjunction with quantitative and qualitative methods. The quantitative aspect of research is composed of 469 students, who has been studying in different types of secondary schools in Adana in 2012-2013 educational year. The percentages of the responses to the survey and demographic variables and frequencies are set. Also cross breading was made with the responses and the demographic variables. The data obtained was decaded and interpreted with the help of SPSS for windows version 15.0 in the computer by using statistical techniques. In order to investigate, views of the participants in-dept and multi-dimensional interview method was used in the data collection process. Interview was applied on 14 club teachers, working in secondary schools in the central district of Adana and six managers in these institutions. Data was prepared with semi-structured interview form, designed by the researcher. In the analysis of data from the content, analysis technique was used. It is determined that %31 of the students have not been participated in any activity of educational clubs, they have been involved in. Most of the students agree on the idea that the educational clubs are necessary and beneficial for themselves.Bu çalışma Ç.Ü. Bilimsel Araştırma Projeleri Birimi tarafından desteklenmiştir. Proje No: EF2013YL15

Principal functions of boundary-value problem with quadratic spectral parameter in boundary conditions

WOS:000396686500031In this paper, we determine the principal functions corresponding to the eigenvalues and the spectral singularities of the boundary value problem (BVP) -y '' + q(x)y = lambda(2)y, x is an element of R+ = [0, infinity] (alpha(0) + alpha(1) lambda + alpha(2)lambda(2))y'(0) - (beta(0) + beta(1)lambda + beta(2)lambda(2)) y (0) =0, where q is a complex-valued function, alpha(i), beta(i) is an element of C, i = 0,1,2 and lambda is a eigenparameter, and introduce the convergence properties of principal functions