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Density Functional Theory (DFT) is one of the most important application of Carbon Nanotubes (CNTs). Because of the chemical and physical characteristics of carbon, CNTs play an important role in the field of nanotechnology. The most difficult part of CNT simulations is DFT calculations that take hours or even days. In this study, a Support Vector Regression (SVR) model that reduces the atomic coordinate calculation of CNT simulation duration has been proposed. u, v, and w coordinates which obtained from CNT simulations are predicted with high accuracy using the SVR method within minutes. A dataset containing 10721 samples was created using CASTEP software for the prediction model. The dataset consists of the atomic coordinates and chiral vectors. To evaluate the accuracy of the proposed model, Mean Square Error (MSE), Mean Absolute Error (MAE), Standard Error of the Estimate (SEE) and Correlation Coefficient (R) metrics were used. The dataset is studied separately with and without using 10-fold cross-validation. The results obtained from this study can be used in two ways: 1) The atomic coordinates can be predicted with a low-error without using a simulation program, 2) The estimated results can be used as an initial value of simulation software for reducing duration of the atomic coordinate simulation seriously. [ABSTRACT FROM AUTHOR]

Background: The predictive value of 6-12th and 24th hour bilirubin levels in determining significant hyperbilirubinemia among healthy term neonates was evaluated in this study. Methods: Term, healthy neonates with hyperbilirubinemia were included. Serum total bilirubin levels were determined at the postnatal 6-12th and at the 24th, 48th, 72nd and 96th hours. The predictive value of the 6-12th and 24th hour bilirubin levels in determining significant hyperbilirubinemia was evaluated by ROC analysis. Results: Of the 276 neonates, 134 (48.5%) were males and 142 (51.5%) were females. Clinical jaundice was observed in 240 (86%) of them. Thirty seven (13.4%) developed significant hyperbilirubinemia. A bilirubin level at the 6-12th hours higher than 3.9 mg/dl was found to be significant with a sensitivity and specificity of 67.6% and 64.9%, respectively (p<0.002). The positive predictive value was 22.9% and the negative predictive value was 92.8%. A bilirubin level at the 24th hour higher than 7.7 mg/dl was found to be significant with a sensitivity and specificity of 78.4% and 77.8%, respectively (p<0.001). The positive predictive value was 35.4% and the negative predictive value was 95.9%. Total bilirubin levels at the 24th hour were found to be more predictive than bilirubin levels at the 6-12th hours in determining significant hyperbilirubinemia. Conclusion: Total bilirubin levels at the 24th hour is a valuable criteria in determining significant hyperbilirubinemia among term neonates discharged early. [ABSTRACT FROM AUTHOR]

The purpose of this study is to determine consumer behavior towards organic products in Samsun city center and to determine the factors affacting their preferences of organic products. The study was interviewed with 478 consumers living the city center of Samsun. According of the findings, ease of accesibility of organic products, spouse's educational level, paying extra for the organic produce, aware of food health benefits, considering the harmful effects of conventional produce, having complete knowledge of organic farming and one unit increase household number income to result increase consumption of organic produce. Consumers were not aware of the certification and control process. As a result, easy of accesibility of organic produces in the supermarkets need to be improved. [ABSTRACT FROM AUTHOR]

Bilimsel süreç becerileri, her bireyin, bilim okuryazarı olabilmek, bilimin doḡasını kavrayarak yaşam kalitesini ve standardını artırabilmek için günlük yaşamın her aşamasında kullanabileceḡi yetenekleri içerir. Bu çalışmanın amacı; ortaöḡretim öḡrencilerine uygun temel ve üst düzeyde bilimsel süreç becerilerini (BSB) ölçen geçerli, güvenilir ve güncel bir ölçme aracı geliştirmektir. Test geliştirilirken, yenilenen 9., 10. ve 11. sınıf kimya ders programı içerik kazanımları, kimya-teknoloji-toplum-çevre kazanımları ve iletişim, tutum ve deḡer kazanımlarından yararlanılarak günlük yaşamda karşılaşılan problem durumları verilmiş, öḡrenciden bilimsel süreç becerilerini kullanarak bu durumları çözmesi beklenmiştir. Çalışmaya İzmir ilinde Meslek Lisesi ve Anadolu lisesinden toplam 222 öḡrenci katılmıştır. Toplam 30 çoktan seçmeli sorudan oluşan testin KR20 güvenirlik katsayısı 0.83 olarak hesaplanmıştır. Geliştirilen test; gözlem, sınıflama, ölçme, ilişki kurma, çıkarım yapma, tahminde bulunma, hipotez kurma, deḡişken belirleme ve kontrol etme, araştırma tasarlama, veri toplama ve kaydetme ve verilerin analizi alt faktörlerinden oluşmaktadır. Test, alanyazında yer alan gözlem, ölçme, verilerin toplanması, problemin belirlenmesi, deney tasarlama, elde edilen verilerin işlenmesi ve görsel olarak ifadesi, yorum ve deḡerlendirme faktörlerinden oluşan modele de uygundur. Testin ilk modele göre yapısının doḡrulayıcı faktör analizi sonucu RMSEA deḡeri 0.024, ikinci modele göre 0.034 olarak bulunmuştur. Sonuçlar testin güvenilir ve geçerli bir araç olduḡunu göstermiştir. [ABSTRACT FROM AUTHOR]

Bu araştırmada ergenlerin anne baba stillerinin ve yaşam doyumlarının kuraldışı davranışları düşük ya da yüksek düzeyde göstermeyi ne derece yordadıḡını belirlemek amaçlanmıştır. Araştırmada 471 'i kız, 410'u erkek olmak üzere toplam 881 ortaöḡretim öḡrencisine ulaşılmış, bu öḡrenciler arasından düşük düzeyde kuraldışı davranış gösteren 262 (%52.2), yüksek düzeyde kuraldışı davranış gösteren 240 (%47.8) olmak üzere toplam 502 öḡrenci (242'si kız, 26O'ı erkek) üzerinde çalışılmıştır. Araştırmada "Kuraldışı Davranış Ölçeḡi", "Anne Baba Tutum Ölçeḡi"ve "Çokboyutlu Öḡrenci Yaşam Doyumu Ölçeḡi" kullanılmıştır. Verilerin analizinde Lojistik Regresyon Analizi'nden yararlanılmıştır. Lojistik regresyon analizi sonucunda aileden algılanan "kontrol/denetim" ile okul", "aile" ve "benlik" ten algılanan yaşam doyumu deḡişkenlerinin kuraldışı davranışlarda yüksek düzeyde bulunmayı açıklamada anlamlı katkılar yapan deḡişkenler olduḡu saptanmıştır. Sonuçlar daha önce yapılmış araştırmalar çerçevesinde tartışılmış, araştırmanın sınırlılıkları ve daha sonra yapılacak araştırmalara yönelik öneriler sunulmuştur. [ABSTRACT FROM AUTHOR]

In this study, logistic regression model selection methods were compared for the prediction of coronary artery disease (CAD). Methods: Coronary artery disease data were taken from 237 consecutive people who had been applied to İnönü University Faculty of Medicine, Department of Cardiology. Logistic regression model selection methods were applied to CAD data containing continuous and discrete independent variables. Goodness of fit test was performed by Hosmer-Lemeshow statistic. Likelihood-ratio statistic was used to compare the estimated models. Results: Each of the logistic regression model selection methods had sensitivity, specificity and accuracy rates greater than 91.9%. Hosmer-Lemeshow statistic showed that the model selection methods were successful in the description of CAD data. Related factors with CAD were identified and the results were evaluated. Conclusion: Logistic regression model selection methods were very successful in the prediction of CAD. Stepwise model selection methods were better than Enter method based on Likelihood-ratio statistic for the prediction of CAD. Age, diabetes mellitus, hypertension, family history, smoking, low-density lipoprotein, triglyceride, stress and obesity variables may be used for the prediction of CAD. [ABSTRACT FROM AUTHOR]

In this paper, the factors determining the autogas demand in Erzurum has been analyzed by using a logit model. First of all, it has been determined the independent variables correlated with the autogas demand in Erzurum using chi-square tests. The first model estimated by Maximum Likelihood is statistically significant. But some of the independent variables in the model aren't significant. Subtracting the most insignificant variables, the second model has been established. The significant independent variables in the model are the automobile owner's monthly household income, the automobile owner 's revenue expectation, the secondhand automobile value, the age of automobile, the engine type of automobile, and how many years has gasoline or autogas been used. [ABSTRACT FROM AUTHOR]