The unit generalized half normal distribution: A new bounded distribution with inference and application

In this paper, a new distribution defined on (0,1) bounded interval has been introduced. We define the distribution by transformation of a positive random variable (rv) with respect to exponential function. Basic distributional properties of newly defined distribution are studied. We pointed out the different estimation methods for its parameters’ estimations. We assess the performance of the estimators of these estimation methods by the simulation study. Application of the proposed distribution to a real data set shows better fit than many known distributions on the (0,1) interval

Cerebral hemodynamics in patients with cirrhosis

Background/Aims: Cirrhosis causes a decrease in cerebral blood flow because of a hyperdynamic circulatory state. We aimed to study the cerebral hemodynamic parameters in patients with decompensated cirrhosis and their relationship to the Child-Pugh and Model for End-Stage Liver Disease (MELD) scores. Materials and Methods: We used transcranial Doppler to investigate the cerebral hemodynamic parameters, namely the mean flow velocity of the middle cerebral artery, pulsatility index (PI), and resistive index (RI), in 50 patients who had decompensated cirrhosis and in a control group of 50 healthy people. We also investigated their relationship to the Child-Pugh and MELD scores. Results: Patients with cirrhosis had a lower mean flow velocity than those in the control group. Further, patients with cirrhosis had higher PI and RI values. There was a positive correlation between PI and the Child-Pugh score. In addition, there was a positive correlation among PI, RI, and the MELD score. The RI values of patients with ascites were higher than those of patients without ascites. Conclusion: Cerebral autoregulation might be impaired in patients with cirrhosis. Cerebral resistance proportionally increases to disease severity. There was a positive correlation among PI, RI, and MELD scores, which means that transcranial Doppler might be useful not only in the follow-up of the severity of the disease but also in determining the survival of these patients. © Copyright 2016 by The Turkish Society of Gastroenterology

On the unit Burr-XII distribution with the quantile regression modeling and applications

In this paper, we modify the Burr-XII distribution through the inverse exponential scheme to obtain a new two-parameter distribution on the unit interval called the unit Burr-XII distribution. The basic statistical properties of the newly defined distribution are studied. Parameters estimation is dealt and different estimation methods are assessed through two simulation studies. A new quantile regression model based on the proposed distribution is introduced. Applications of the proposed distribution and its regression model to real data sets show that the proposed models have better modeling capabilities than competing models

Topp-Leone Nadarajah Haghighi dağılımı

In this paper, a three parameter model which can be used in modeling survival data, reliability problems and fatigue life studies has been studied. We derived explicit expressions for some of its statistical and mathematical identifying properties such as ordinary moments, generating function, incomplete moments and order statistics. The maximum likelihood estimations of model parameters were also obtained -being based on complete sample. We assessed the performance of the maximum likelihood estimators in terms of standard deviations, bias and mean squared errors by means of a simulation study. The usefulness of the model was illustrated by using a real data set. The proposed distribution provides better fits than some wellknown generalized distributions under the same criteria of comparison.Bu çalışmada yaşam verileri, güvenirlik problemleri ve yorulma ömrü çalışmalarında kullanılabilecek üç parametreli bir model üzerinde çalışılmıştır. Bu modele ait momentler, üreten fonksiyonlar, tamamlanmamış momentler ve sıra istatistikleri gibi istatistiksel ve matematiksel özellikler türetilmiştir. Tam örneklem durumuna dayalı olarak, model parametrelerinin sıradan en çok olabilirlik tahminleri elde edilmiştir. Bir simülasyon çalışması ile model parametrelerinin en çok olabilirlik tahmin edicilerinin performansları, standart sapma, yan ve hata kareler ortalamaları ile değerlendirilmiştir. Modelin kullanışlılığı, bir gerçek veri setine dayalı olarak gösterilmiştir. Önerilen dağılım bazı karşılaştırma kriterleri altında, literatürde iyi iyi bilinen birtakım dağılımlardan daha iyi uyum sağlamıştır

The Cyprus question in the making and the attitude of the Soviet Union towards the Cyprus question (1960-1974)

Ankara : The Department of International Relations, Bilkent University, 2008.Thesis (Master's) -- Bilkent University, 2008.Includes bibliographical references leaves 83-88.In this study, the Soviet attitude towards the Cyprus Question between the years 1960-1974 will be analyzed within the framework of Cold War. In this context, the reasons of the emergence and development of the Cyprus Question was explicated. The differences between Stalin’s foreign policy during the post-Second World War and that of post-Stalin period regarding the Third World countries in the Middle-East will be emphasized. In this connection, increasing influence of the Soviet Union in these countries will be explained with reference to certain related treaties. In addition, the developing relations between Cyprus and the Soviet Union which commenced with the independence of Cyprus in 1960 and further flourished as a result of intersecting interests of Makarios and Soviet Union will be explained. iv Together with these developed relations, the impact of the Soviet Union on the Cyprus Question until 1974 will be examined.Aslan, Mustafa ÇağatayM.S

On the arcsecant hyperbolic normal distribution. Properties, quantile regression modeling and applications

This work proposes a new distribution defined on the unit interval. It is obtained by a novel transformation of a normal random variable involving the hyperbolic secant function and its inverse. The use of such a function in distribution theory has not received much attention in the literature, and may be of interest for theoretical and practical purposes. Basic statistical properties of the newly defined distribution are derived, including moments, skewness, kurtosis and order statistics. For the related model, the parametric estimation is examined through different methods. We assess the performance of the obtained estimates by two complementary simulation studies. Also, the quantile regression model based on the proposed distribution is introduced. Applications to three real datasets show that the proposed models are quite competitive in comparison to well-established models

Oransal lindley fréchet dağılımının bazı teorik ve hesaplamalı yönleri

In this article, we study an extension of the Fréchet model by using the the odd Lindley-G family of distributions, which was introduced by [17]. Its some statistical properties such as quantile function, density shapes, moments, generating functions and order statistics are obtained. We estimate its parameters by maximum likelihood method. The Monte Carlo simulation is used for assessing the performance of the maximum likelihood method. The usefulness of the odd Lindley Fréchet model is illustrated by means of three real data sets.Bu çalışmada, Fréchet modelinin genişletilmiş bir versiyonu [17] tarafından önerilen oransal Lindley dağılım ailesi kullanılarak çalışılmıştır. Bu modele ait kuantil fonksiyonu, yoğunluk biçimi, momentler, üreten fonksiyon ve sıra istatistikleri gibi istatistiksel özellikleri elde edilmiştir. Model parametrelerinin en çok olabilirlik tahminleri elde edildi. En çok olabilirlik parametre tahminleri için bir simülasyon çalışılması verilmiştir. Önerilen modelin gerçek veri seti üzerindeki uygunluğu için üç veri analizi yapılmıştır

The log exponential-power distribution: Properties, estimations and quantile regression model

Recently, bounded distributions have attracted attention. These distributions are frequently used in modeling rate and proportion data sets. In this study, a new alternative model is proposed for modeling bounded data sets. Parameter estimations of the proposed distribution are obtained via maximum likelihood method. In addition, a new regression model is defined under the proposed distribution and its residual analysis is examined. As a result of the empirical studies on real data sets, it is observed that the proposed regression model gives better results than the unit-Weibull and Kumaraswamy regression models

Effects of Hot Isostatic Pressing and Heat Treatments on Structural and Corrosion Properties of Direct Metal Laser Sintered Parts

Purpose – This paper aims to investigate the effects of various heat treatments on microstructure, hardness, porosity and corrosion properties of the parts. Design/methodology/approach – Hot isostatic pressing (HIP) process, various heat treatments and their combinations were applied to the AlSi10Mg parts produced by direct laser metal sintering (DMLS). Findings – It has been found that the HIP process, which is a post-processing process, reduces the amount of porosity in DMLS-AlSi10Mg material, thus improves corrosion resistance significantly. Originality/value – In this study, the HIP process and subsequent T6 heat treatments were applied to AlSi10Mg parts produced by the DMLS technique. The study aims to increase the corrosion resistance of AlSi10Mg parts by reducing porosity with the HIP process and by altering the microstructure with the T6 process