Box–Cox–type Transformations for Linear and Logistic Models with Random Effects.

Random effect models have become a mainstream statistical technique over the last decades; and the same can be said for response transformation models such as the Box-Cox transformation. The latter ensures that the assumptions of normality and of homoscedasticity of the response distribution are fulfilled, which are essential conditions for the use of a linear model or a linear mixed model. However, methodology for response transformation and simultaneous inclusion of random effects has been developed and implemented only scarcely, and is so far restricted to Gaussian random effects. The first aim of this thesis is to develop such methodology, thereby not requiring parametric assumptions on the distribution of the random effects. This is achieved by extending the “Nonparametric Maximum Likelihood” towards a “Nonparametric Profile Maximum Likelihood” (NPPML) technique. The implemented techniques allow to deal with overdispersion as well as two-level data scenarios in general linear models. The second part of this thesis considers the transformation of mixed-effects logistic models, with the aim of improving model fit. In binary data, link functions other than the logit can be used to connect predictors with the response. The Box-Cox transformation is used in mixed–effects binary regression models as an alternative link function for linearization purposes. The NPPML approach is used similarly as before, with some adjustments. The proposed approach is implemented in the R package boxcoxmix. Simulation studies and applications on real data are carried out to study the performance of this approach

Generalized Partial Least Squares Approach for Nominal Multinomial Logit Regression Models with a Functional Covariate

Functional Data Analysis (FDA) has attracted substantial attention for the last two decades. Within FDA, classifying curves into two or more categories is consistently of interest to scientists, but multi-class prediction within FDA is challenged in that most classification tools have been limited to binary response applications. The functional logistic regression (FLR) model was developed to forecast a binary response variable in the functional case. In this study, a functional nominal multinomial logit regression (F-NM-LR) model was developed that shifts the FLR model into a multiple logit model. However, the model generates inaccurate parameter function estimates due to multicollinearity in the design matrix. A generalized partial least squares (GPLS) approach with cubic B-spline basis expansions was developed to address the multicollinearity and high dimensionality problems that preclude accurate estimates and curve discrimination with the F-NM-LR model. The GPLS method extends partial least squares (PLS) and improves upon current methodology by introducing a component selection criterion that reconstructs the parameter function with fewer predictors. The GPLS regression estimates are derived via Iteratively ReWeighted Partial Least Squares (IRWPLS), defining a set of uncorrelated latent variables to use as predictors for the F-GPLS-NM-LR model. This methodology was compared to the classic alternative estimation method of principal component regression (PCR) in a simulation study. The performance of the proposed methodology was tested via simulations and applications on a spectrometric dataset. The results indicate that the GPLS method performs well in multi-class prediction with respect to the F-NM-LR model. The main difference between the two approaches was that PCR usually requires more components than GPLS to achieve similar accuracy of parameter function estimates of the F-GPLS-NM-LR model. The results of this research imply that the GPLS method is preferable to the F-NM-LR model, and it is a useful contribution to FDA techniques. This method may be particularly appropriate for practical situations where accurate prediction of a response variable with fewer components is a priority

The Effect of High Pressures and High Temperatures on the Properties of Water Based Drilling Fluids

Tremendous amounts of hydrocarbons are located in deeper formations where higher pressures and temperatures are experienced. Designing a proper drilling fluid that can tolerate such high-pressure, high-temperature (HP/HT) conditions is a challenging task. The work presented in this paper is focused on investigating the rheological behavior of water-based drilling fluids with different properties at extremely high pressure and temperature conditions using a state-of-the-art viscometer capable of measuring drilling fluids properties up to 600 °F and 40,000 psig. The results of this study show that the viscosity, yield point and gel strength decrease exponentially with increasing temperature until the mud samples fail. This behavior is the result of the thermal degradation of the solid, polymers, and other components of the mud samples. Increase in intermolecular distances due to high temperature will lower the resistance of the fluid to flow and, hence, its viscosity, yield point, and gel strength will reduce. Moreover, conducting this study led to the conclusion that viscosity, yield point, and gel strength increase linearly as the pressure increase. Pressure’s effect on these parameters, however, is more apparent at lower temperatures. Ultimately, the study concluded that the mud samples that were used, which are standard industrial types, failed at a temperature of 250 oF and that the combined effect of temperature and pressure on mud’s rheology is complex.Key words: Drilling fluids; HPHT; Rheology; Water based mu

Comparative Study of Using Oil-Based Mud Versus Water-Based Mud in HPHT Fields

Growing demand for oil and gas is driving the exploration and production industry to look for new resources in un-explored areas, and in deeper formations. According to the Bureau of Ocean Energy Management, Regulation and Enforcement, former Minerals Management Service (MMS), over 50% of proven oil and gas reserves in the United States lie below 14,000 ft. subsea. In the Gulf of Mexico some wells were drilled at 27,000 ft below seabed with reservoir temperatures above 400 °F and reservoir pressures of 24,500 psi. As we drill into deeper formations we will experience higher pressures and temperatures.Drilling into deeper formation requires drilling fluids that withstand higher temperatures and pressures. The combined pressure-temperature effect on drilling fluid’s rheology is complex. This provides a wide range of difficult challenges and mechanical issues. This can have negative impact on rheological properties when exposed to high pressure high temperature (HPHT) condition and contaminated with other minerals, which are common in deep drilling. High Pressure and High Temperature (HPHT) wells have bottom hole temperatures of 300 °F (150 °C) and bottom hole pressures of 10,000 psi (69 MPa) or higher.Water-Based mud (WBM) and Oil-Based mud (OBM) are the most common drilling fluids currently used and both have several characteristics that qualify them for HPHT purposes. This paper compares the different characteristics of WBM and OBM to help decide the most suitable mud type for HPHT drilling by considering mud properties through several laboratory tests to generate some engineering guidelines. The tests were formulated at temperatures from 100 °F up to 600 °F and pressures from 5,000 psi to 25,000 psi. The comparison will mainly consider the rheological properties of the two mud types of mud and will also take into account the environmental feasibility of using them. Key words: Oil-based mud; Water-based mud; HPHT field

Constitutional Controls for Necessary Legislation in the United Arab Emirates (UAE): Comparative Study- 1st Part

Jurisprudence and the judiciary admitted the extraordinary jurisdiction of executive authority in the area of legislation. Through this paper, we have addressed many questions about the nature of the exceptional circumstances and how determined by the jurisprudence and the judiciary in both France and Egypt. Considering that Article 16 of the Constitution of the Fifth Republic in France, issued in 1958, the basis of the theory of historical necessity in Arab constitutions. Analytical comparative method was used to know the facts about the necessity legislations and its historical development and grounds in both France and Egypt. Then, we dealt with the constitutional standards on which the basis of the legislations authorities is determined in necessity case in the Constitution of the United Arab Emirates and the Constitution of the State of Bahrain , the Constitution of the State of Kuwait , the Constitution of the State of Qatar and the Constitution of the Kingdom of Jordan. We studied the legal basis for the distinction between legislative and administrative work and the nature of the decrees necessary before the approval of the Legislative Council and after approval of the Legislative Council. Search has been divided into three main chapters, the first chapter deals with the definition and development of necessary legislations. While the second chapter concerns with the necessary legislations in some GCC countries. Dr. Amani Omar Mohammed Assistant Professor of Public law- College of Law at Al Ain University of Sciences and Technology - UAE

Legemiddelgjennomganger hos psykisk utviklingshemmede i Oslo kommune. Legemiddelrelaterte problemer og tiltak

Bakgrunn: Systematiske legemiddelgjennomganger i tverrfaglig team kan være til hjelp for å identifisere potensielle og aktuelle legemiddelrelaterte problemer (LRP). Oslo kommune valgte i 2015 å prioritere legemiddelgjennomganger for psykisk utviklingshemmede, en gruppe mennesker som bruker mange legemidler. Dette er den første studien på legemiddelgjennomganger og identifisering av LRP blant psykisk utviklingshemmede i Norge. Formål: Det er manglende kunnskap om legemiddelrelaterte problemer hos pasienter med psykisk utviklingshemming. Formålet med dette prosjektet var derfor å undersøke antall og type LRP som ble identifisert gjennom legemiddelgjennomganger hos psykisk utviklingshemmede. I tillegg undersøkte vi hvilke legemiddelgrupper som var hyppigst assosiert med LRP. Metode: Pasientdataene ble hentet fra LRP – skjemaer som var samlet inn av utviklingssenteret for hjemmetjenesten i Oslo kommune. Legemiddelgjennomgangene fant sted hos fastlegen, hvor også hjemmesykepleier/vernepleier og kommunefarmasøyt deltok. Under legemiddelgjennomgangene foreslo kommunefarmasøyten vurderingstiltak for å løse legemiddelrelaterte problemer etter egen vurdering, og registrerte hvorvidt legen tok disse til følge. Deskriptive analyser av datasettet ble foretatt ved hjelp av SPSS. Resultat: Totalt mottok vi skjema for 40 pasienter med psykisk utviklingshemming, i alderen 34 – 77 år. I de tverrfaglige legemiddelgjennomgangene ble det identifisert 191 LRP, i gjennomsnitt 4,9 LRP per pasient. Minst ett LRP ble identifisert hos 97 % av pasientene. Innspill fra kommunefarmasøyten ble tatt i følge i 79 % av alle registrerte LRP. De hyppigste LRP var tilknyttet «unødvendig legemiddelvalg (24 %), bivirkninger (11 %) og for lav dose (11 %). De mest brukte legemiddelgruppene var antiepileptika, anxiolytika og midler mot forstoppelse. Legemiddelgruppene hyppigst assosiert med LRP var antipsykotika, antidepressiva og anxiolytika. Konklusjon: Denne studien har bidratt til ny kunnskap om legemiddelrelaterte problemer og legemiddelbruk hos en sårbar pasientgruppe. Denne studien viser at psykisk utviklingshemmede bruker mange legemidler og har mange, men andre typer legemiddelrelaterte problemer sammenliknet med andre pasientgrupper. Identifiserte legemiddelrelaterte problemer ble i svært stor grad løst av det tverrfaglige teamet. Denne studien viser at tverrfaglige systematiske legemiddelgjennomganger egner seg som metode for å kvalitetssikre legemiddelbehandlingen, samt bidrar til å øke pasientsikkerheten for denne pasientgruppen

Constitutional Controls for Necessary Legislation in the UAE: A comparative Study- 2nd Part

The third chapter deals with the practical application of the necessary legislations in the United Arab Emirates. This chapter is divided into two sections, the first one addresses the especial nature of the ruling system and the legislation authority according to the U.A.E. constitution, While the second section is devoted to the study of constitutional standards for the legislation necessary according to the constitution of the United Arab Emirates. I concluded that the necessary legislations are applicable in all countries that protect constitutional legitimacy. These legislations are not used except in cases of extreme necessity, and they have common features in all constitutions where they are adopted although they may have different names from one constitution to the other

Muslim, Young and Urban: A Comparative Ethnography of Representation and Mobility among Young Adults Who Identify as Muslim in Copenhagen, Denmark and Montreal, Canada

This thesis explores the lives of young adults (18-25-year-old) who identify as Muslim in Copenhagen and Montreal. As a comparative ethnography, it sets out to examine the transatlantic similarities and differences among young people who grew up in an era where Muslims were often represented as a foreign object in need of integration, and at times as threatening. The thesis investigates processes of representation depicting young Muslims’ life histories, social positions and social identifications. Furthermore, it follows these young individuals’ movements through their cities and the spatial narratives they construct through these movements. I have sought to unravel the complexity of my interlocutors’ self-ascribed identifications of Muslim and Copenhagener/Montrealer – as well as the many other identifications they adopted - by furnishing their narratives with spatial representations; in many ways, these young people were shaped by and shaped the social spaces they inhabit. In so doing, the thesis seeks to counter the populist positioning of ‘the Muslim other’ by informing the broader themes entailed in the intersection between young adulthood, social mobility, spatial mobility, urban life and self-identification as a Muslim in a Western society. The ethnographic methods I employed in this study were threefold; I used participant observation to study my interlocutors’ social contexts, the cities they live in, and the public debates that permeate their city spaces. Semi-structured interviews were another important avenue for understanding how my interlocutors represented their lives, experiences and social positions. Finally, I used interlocutor-directed city tours to explore their movements in their localities. This last method was an essential instrument with which to situate and contextualize my interlocutors’ lives, experiences and navigations within their cities

Effects of sowing method and herbicide application on growth, yield and water productivity of two wheat cultivars

Water management and weed control are crucial components in maximizing wheat yield and water productivity. Little research work has been done on the relationship between sowing methods, chemical weed control and wheat varieties. Field experiments were conducted during 2013/14-2014/15 seasons to evaluate the effect of four sowing methods and herbicide application on the performance of two wheat cultivars at the Gezira and New Halfa Research Stations. The experiment was arranged in a split-split plot design with four replicates, the main plots were assigned to herbicide application (sprayed and unsprayed), sub-plots were allocated to sowing methods (broadcasting + ridging, bed-planting, seed drill and wide level disc), and sub-sub-plots were assigned to wheat cultivars (Bohaine and Imam). Results showed that herbicides did not affect the yield and yield components of wheat for both seasons in the Gezira. Irrespective of herbicide application, seed drill resulted in the highest wheat yield for the two seasons. New Halfa results revealed that the crop growth and yield components were significantly affected. However, the two wheat cultivars resulted in higher yield with bed-planting method under sprayed condition. The interaction of herbicide application and bed-plating methods resulted in higher water productivity, which could be attributed to the lower amount of water applied compared to the other treatments. These results indicated that in the Gezira, unsprayed seed drill and wide level disc sowing methods can be used without yield reduction of wheat. Moreover, herbicides application with bed-planting sowing method in both sites can be used to improve water use efficiency. إدارة مياه الري ومكافحة الحشائش هي أحدى العوامل الأساسية لتعظيم انتاجية القمح وزيادة كفاءة مياه الري. أجريت تجارب حقلية خلال موسمي 2013/14 و 2014/15 لتقييم أثر أربعة طرق للزراعة ومبيد الحشائش على انتاجية صنفين من القمح بمحطتي بحوث الجزيرة وحلفا الجديدة. تم استخدام تصميم القطع المنشقة مرتين بأربع مكررات. وضعت معاملات مبيد الحشائش في الأحواض الرئيسية ووضعت طرق الزراعة في الأحواض الفرعية بينما وضعت الأصناف في الأحواض الفرعية . أوضحت النتائج أن مبيد الحشائش لم يؤثر على الإنتاجية ومكوناتها خلال الموسمين بمحطة بحوث الجزيرة. بغض النظر عن مبيد الحشائش، الزراعة في سطور أعطت أعلى انتاجية خلال الموسمين. كذلك أوضحت النتائج بمحطة بحوث حلفا الجديدة أن النمو ومكونات الانتاجية تأثرتا بصورة معنوية، حيث وجد أن صنفي القمح سجلتا أعلى انتاجية باستخدام الزراعة في مساطب والمكافحة الكيميائية للحشائش. إن أثر تفاعل الزراعة في مساطب والمكافحة الكيميائية للحشائش انتجت أعلى كفاءة مياه ري وذلك يمكن مرده لقلة كمية مياه الري المضافة مقارنةً بالمعاملات الأخرى. النتائج أعلاه تشير إلى أن الزراعة في سطور والزراعة باستخدام الدسك العريض يمكن استخدامهما بالجزيرة لإنتاج القمح دون نقص يذكر في الإنتاجية. اضافةً الي ذلك، فان اضافة مبيد الحشائش لطريقة الزراعة في مساطب يمكن أن تحسن من كفاءة استخدام مياه الري في كلا الموقعين

Load Reduction in Wind Energy Converters Using Individual Pitch Control

With the increase in population, the needs of living a better life are demanding more energy supply. Moreover, environment and safety are important factors in development of any energy producing system. That's why renewable energy systems are most reliable if they are developed with qualitative and quantitative research. The wind energy converters are heavy machines used to convert wind energy to electrical power. The European Wind Energy Association (EWEA) has set different targets till 2020-30 to get more energy from renewable sources as well as wind energy converters. This thesis work is to develop the basic concept of individual pitch control of wind energy converter to get maximum possible value of power coefficient. For this purpose, reliable and efficient sensor, sensing bending moment, stresses and strains caused by wind, gravitational and centrifugal forces at the root of the blade, are very important. A simple model of the blade with analysis of the moments generated by the wind and the gravity of each blade, when the blade is rotating is provided and is checked by the real values measured by fiber Bragg grating sensors of Fos4x German Company