The model-free analysis of NMR relaxation data, which is widely used for the study of protein dynamics, consists of the separation of the Brownian rotational diffusion from internal motions relative to the diffusion frame and the description of these internal motions by amplitude and timescale. Through parametric restriction and the addition of the Rex parameter a number of model-free models can be constructed. The model-free problem is often solved by initially estimating the diffusion tensor. The model-free models are then optimised and the best model is selected. Finally, the global model of all diffusion and model-free parameters is optimised. These steps are repeated until convergence. This thesis will investigate all aspects of the model-free data analysis chain. (For complete abstract open document)

The present research investigated the challenges and problems facing the public sector institutions regarding the processes, procedures, practices, steps and methods used for human resource recruitment and selection. The South African government outlawed unfair discrimination to promote equality and equity in the labour force. This state of affairs has direct implications for employment practices such as recruitment and selection in the public service. Without a comprehensive recruitment and selection model, public service departments could contravene legislative requirements. As a result, these public service departments then may not succeed in attracting and appointing the best candidates for vacant positions. The intension of this study was to determine the extent to which functions of human resource management (HRM) reflect the spirit and stipulations of the statutory and regulatory framework. These functions include job analysis, job evaluation, job design, job profiles, and human resource planning, as well as induction and orientation. The aim is further to verify to what extent these functions influence recruitment and selection practices. A qualitative research design was used to construct a comprehensive human resource recruitment and selection model. This model is the result of a thorough analysis of comparative recruitment and selection theories, approaches, international best practice, and of existing models. A case study was undertaken within the Department of Justice and Constitutional Development (DOJ&CD). Data was collected by using a questionnaire from a representative sample. The target population comprised senior and middle managers from the National Office in Pretoria and North West Province responsible for human resource functions. They are divided into five sub-clusters. Based on the core findings of this research it was established that the DOJ&CD experiences inefficiencies as far as the following aspects of human resource management are concerned: alignment, development and implementation of appropriate human resource strategies, systems, processes, procedures and methods. This also includes the approaches for recruitment and selection. The DOJ&CD mainly utilises traditional processes of recruitment and selection that do not adequately reflect international best practice and, furthermore, do not adhere to all the stipulations of the myriad forms of legislation that are governing human resources in the public service. A comprehensive model for recruitment and selection was thus of the utmost importance to guide the Department in its recruitment and selection endeavours. The model that is designed as the main contribution of this research is aimed at addressing these challenges. The comprehensive model is intended to guide the DOJ&CD‟s human resource practitioners on recruitment and selection. This is done by means of a processmap and a flow-chart approach. Based on the literature review and empirical study, best practice is proposed that can be associated with each phase or step in the recruitment and selection process. The criteria for the development of the model was based on the theoretical relationship among elements and variables such as strategy, structure, job analysis, job description, job specification and job evaluations, and how these elements are linked to recruitment and selection processes. Such a comprehensive human resource recruitment and selection model can assist practitioners to align all human resource activities and functions within public service departments. This will help to realise their organisational objectives and to operationalise their strategic imperatives successfully. / PhD (Public Management and Governance), North-West University, Potchefstroom Campus, 2014

The present research investigated the challenges and problems facing the public sector institutions regarding the processes, procedures, practices, steps and methods used for human resource recruitment and selection. The South African government outlawed unfair discrimination to promote equality and equity in the labour force. This state of affairs has direct implications for employment practices such as recruitment and selection in the public service. Without a comprehensive recruitment and selection model, public service departments could contravene legislative requirements. As a result, these public service departments then may not succeed in attracting and appointing the best candidates for vacant positions. The intension of this study was to determine the extent to which functions of human resource management (HRM) reflect the spirit and stipulations of the statutory and regulatory framework. These functions include job analysis, job evaluation, job design, job profiles, and human resource planning, as well as induction and orientation. The aim is further to verify to what extent these functions influence recruitment and selection practices. A qualitative research design was used to construct a comprehensive human resource recruitment and selection model. This model is the result of a thorough analysis of comparative recruitment and selection theories, approaches, international best practice, and of existing models. A case study was undertaken within the Department of Justice and Constitutional Development (DOJ&CD). Data was collected by using a questionnaire from a representative sample. The target population comprised senior and middle managers from the National Office in Pretoria and North West Province responsible for human resource functions. They are divided into five sub-clusters. Based on the core findings of this research it was established that the DOJ&CD experiences inefficiencies as far as the following aspects of human resource management are concerned: alignment, development and implementation of appropriate human resource strategies, systems, processes, procedures and methods. This also includes the approaches for recruitment and selection. The DOJ&CD mainly utilises traditional processes of recruitment and selection that do not adequately reflect international best practice and, furthermore, do not adhere to all the stipulations of the myriad forms of legislation that are governing human resources in the public service. A comprehensive model for recruitment and selection was thus of the utmost importance to guide the Department in its recruitment and selection endeavours. The model that is designed as the main contribution of this research is aimed at addressing these challenges. The comprehensive model is intended to guide the DOJ&CD‟s human resource practitioners on recruitment and selection. This is done by means of a processmap and a flow-chart approach. Based on the literature review and empirical study, best practice is proposed that can be associated with each phase or step in the recruitment and selection process. The criteria for the development of the model was based on the theoretical relationship among elements and variables such as strategy, structure, job analysis, job description, job specification and job evaluations, and how these elements are linked to recruitment and selection processes. Such a comprehensive human resource recruitment and selection model can assist practitioners to align all human resource activities and functions within public service departments. This will help to realise their organisational objectives and to operationalise their strategic imperatives successfully. / PhD (Public Management and Governance), North-West University, Potchefstroom Campus, 2014

The selection of science fiction was researched to determine how science fiction should be evaluated and selected in the context of the public library. The first sub-problem to be researched concerned the cultural, societal and literary origins of this genre, after which its distinct phases of development were studied as well as the characteristic essence of science fiction which would affect its selection per se, specifically whether conventional literary criteria are suitable for the evaluation of items of science fiction during selection. The next sub-problem focused on, was whether theory can explain the process of fiction selection, The succeeding sub-problem was to empirically Study current practice in science fiction selection. Survey research was conducted amongst selected major urban/regional public library services in the USA. Final research results indicated that science fiction is a sophisticated, multi-textured genre which differs significantly from fellow popular genres, Science fiction is viewed by some critics as being on the cusp of post-modernism, a significant body of work in contemporary literature, and a supreme expression of late capitalism. Research further showed that no satisfactory evaluative criteria exist. It was also established that theory of fiction selection is not always capable of explaining or guiding the process of fiction selection. There is no model for the selection of science fiction. Finn guiding principles for science fiction selection could be formulated by the aid of this study. The study concluded with a specially-designed model for the selection of science fiction (including a scorecard with specially-compiled criteria for evaluating items), as well as a suggested core collection. A structured approach should be followed by the science fiction selector. The guiding principles and core collection which were formulated in this study, the set of special criteria as well as the model, together demonstrate that the selection of science fiction can be structured, controlled and guided within established parameters. / Information Science / D. Lit. et Phil. (Information Science)

最近幾年來，網際網路的出現及應用面的廣泛，改變了企業的資訊架構。從Client/Server擴展到以Web為應用程式的平台，企業面臨了資訊架構的重整，企業網路、電子商務都是現今最新的應用。由於全球資訊網採開放架構，並以HTML、HTTP為標準，使得資訊業者有所依循，開發出許多產品來滿足企業的需求。隨著Web的廣泛使用，應用程式架構、介面與行為特質都將與以往有著大大的不同，元件及交易導向的Web應用程式是勢在必行的路。 對此變革，企業最重要的課題之一是，如何建構完整的企業網路環境以增強競爭力。資料庫系統是企業各種資訊軟體的基礎，在以Web為應用程式的平台的架構下，它仍是其中重要的關鍵元件。選擇資料庫系統必須考慮許多因素，而且現有的資料庫系統的產品很多，各項產品的特性與優點均有不同，每一種產品甚至可再細分成許多元件，可依照需要選用，因此資料庫產品的選擇變成一種複雜的過程。若選擇錯誤則不僅是金錢耗費的損失，更深遠地影響整個企業的順利運作，甚至是企業競爭力的下降，更可能嚴重到影響企業的存續。故資料庫系統的選擇不可不慎。 本文提出一網際網路資料庫體系選擇模式，協助企業在全球資訊網的開放架構及多階層應用系統環境下，評選出符合企業本身狀況及需求的網際網路資料庫系統。此模式內容包含，需求分析與確認、第一至四級網際網路資料庫體系需求屬性之彙整、兩階段的廠商篩選及含加權機制之廠商評比。 最後並將此模式運用於，行政院衛生署藥物食品檢驗局之購置網際網路資料庫設備計劃。 / Internet technology has drastically changed the enterprise computing and platform. Database management and systems represent the core of the change and the key of the new revolution of the information technology and infrastructure. Business information and models have been stored and manipulated through the use of the database technology. Due to the fast growing speed and variety of the database products in the marketplace, managers are having difficult making the right decision in selecting and maintaining the Internet database management and systems. To tackle this issue, we propose a requirements-based software selection model from the user’s viewpoint. In this research, we develop a five-step choice model with an emphasis on the requirement analysis and rank analysis. We collect and compile the functional and non-functional characteristics and features of the Internet database management and systems. We classify and organize them into a four-layer hierarchy and work with the weight mechanism in the rank analysis. This choice model adopts another five-part rank policy in order to produce the final suggestion of software selection. In the end, we apply the new model in a field case study of the Web Database Systems Procurement Project with the National Laboratories of Foods and Drugs, Department of Health, Executive Yuan.

The United States cheese consumption has grown considerably over the years. Using Nielsen Homescan panel data for calendar years 2005 and 2006, this dissertation examines the effect of economic and socio-demographic factors on the demand for disaggregated cheese varieties and on the cheese industry in general. In the first essay, we estimated the censored demand for 14 cheese varieties and identified the respective own-price and cross-price elasticities. Also, non-price factors were determined affecting the purchase of each variety as well as the impact of generic dairy advertising. Results revealed that most of the natural cheese varieties have an elastic demand while the processed cheese products exhibited inelastic demands. Strong substitution and complementarity relationships were identified as well, and a two quarter carry-over effect of advertising was observed for most of cheese demands. Results also showed that household demographics affected the demands differently, depending on the nature of the cheese varieties. The second essay examined the impact of retail promotion on the decision to purchase private label processed cheese products using a probit model. A strong negative relationship was found between national brand manufacturer couponing activity and the private label purchase decision. Therefore, national brand couponing appears to be an effective strategy for manufacturers to deter private label growth. This analysis also shows that the decision of purchasing a private label cheese product is influenced by socio-demographic characteristics of the household, namely household income and size, age and education level of the household head, race, ethnicity, and location. In the third study, the feasibility of fortifying processed cheese with omega-3 is investigated. This ex-ante analysis took into account the market conditions and evaluates the increase in the demand for processed cheese needed to offset the costs of fortification in order to maintain the profitability of manufacturers like Kraft. Initially, the censored demand for processed cheese products is estimated using panel data; subsequently, the profitability of manufacturing such product is determined.This analysis shows that, within reasonable market conditions and reasonable marginal costs, the fortification of processed cheese products with omega-3 fatty acids indeed is feasible from a profitability standpoint to manufacturers.

The selection of science fiction was researched to determine how science fiction should be evaluated and selected in the context of the public library. The first sub-problem to be researched concerned the cultural, societal and literary origins of this genre, after which its distinct phases of development were studied as well as the characteristic essence of science fiction which would affect its selection per se, specifically whether conventional literary criteria are suitable for the evaluation of items of science fiction during selection. The next sub-problem focused on, was whether theory can explain the process of fiction selection, The succeeding sub-problem was to empirically Study current practice in science fiction selection. Survey research was conducted amongst selected major urban/regional public library services in the USA. Final research results indicated that science fiction is a sophisticated, multi-textured genre which differs significantly from fellow popular genres, Science fiction is viewed by some critics as being on the cusp of post-modernism, a significant body of work in contemporary literature, and a supreme expression of late capitalism. Research further showed that no satisfactory evaluative criteria exist. It was also established that theory of fiction selection is not always capable of explaining or guiding the process of fiction selection. There is no model for the selection of science fiction. Finn guiding principles for science fiction selection could be formulated by the aid of this study. The study concluded with a specially-designed model for the selection of science fiction (including a scorecard with specially-compiled criteria for evaluating items), as well as a suggested core collection. A structured approach should be followed by the science fiction selector. The guiding principles and core collection which were formulated in this study, the set of special criteria as well as the model, together demonstrate that the selection of science fiction can be structured, controlled and guided within established parameters. / Information Science / D. Lit. et Phil. (Information Science)

No description available.

No description available.

Diese Dissertation beschäftigt sich mit Methoden zur Behandlung von nicht-ignorierbaren fehlenden Daten und Stichprobenverzerrungen – zwei häufig auftretenden Problemen bei der Analyse von Umfragedaten. Beide Datenprobleme können die Qualität der Analyseergebnisse erheblich beeinträchtigen und zu irreführenden Inferenzen über die Population führen. Daher behandle ich innerhalb von drei verschiedenen Forschungsartikeln, Methoden, die eine Durchführung von sogenannten Sensitivitätsanalysen in Bezug auf Missing- und Selektionsmechanismen ermöglichen und dabei auf typische Survey-Daten angewandt werden können. Im Rahmen des ersten und zweiten Artikels entwickele ich Verfahren zur multiplen Imputation von binären und ordinal Mehrebenen-Daten, welche es zulassen, einen potenziellen Missing Not at Random (MNAR) Mechanismus zu berücksichtigen. In unterschiedlichen Simulationsstudien konnte bestätigt werden, dass die neuen Imputationsmethoden in der Lage sind, in allen betrachteten Szenarien unverzerrte sowie effiziente Schätzungen zuliefern. Zudem konnte ihre Anwendbarkeit auf empirische Daten aufgezeigt werden. Im dritten Artikel untersuche ich ein Maß zur Quantifizierung und Adjustierung von nicht ignorierbaren Stichprobenverzerrungen in Anteilswerten, die auf der Basis von nicht-probabilistischen Daten geschätzt wurden. Es handelt sich hierbei um die erste Anwendung des Index auf eine echte nicht-probabilistische Stichprobe abseits der Forschergruppe, die das Maß entwickelt hat. Zudem leite ich einen allgemeinen Leitfaden für die Verwendung des Index in der Praxis ab und validiere die Fähigkeit des Maßes vorhandene Stichprobenverzerrungen korrekt zu erkennen. Die drei vorgestellten Artikel zeigen, wie wichtig es ist, vorhandene Schätzer auf ihre Robustheit hinsichtlich unterschiedlicher Annahmen über den Missing- und Selektionsmechanismus zu untersuchen, wenn es Hinweise darauf gibt, dass die Ignorierbarkeitsannahme verletzt sein könnte und stellen erste Lösungen zur Umsetzung bereit. / This thesis deals with methods for the appropriate handling of non-ignorable missing data and sample selection, which are two common challenges of survey data analysis. Both issues can dramatically affect the quality of analysis results and lead to misleading inferences about the population. Therefore, in three different research articles, I treat methods for the performance of so-called sensitivity analyses with regards to the missing data and selection mechanism that are usable with typical survey data. In the first and second article, I provide novel procedures for the multiple imputation of binary and ordinal multilevel data that are supposed to be Missing not At Random (MNAR). The methods’ suitability to produce unbiased and efficient estimates could be demonstrated in various simulation studies considering different data scenarios. Moreover, I could show their applicability to empirical data. In the third article, I investigate a measure to quantify and adjust non-ignorable selection bias in proportions estimated based on non-probabilistic data. In doing so, I provide the first application of the suggested index to a real non-probability sample outside its original research group. In addition, I derive general guidelines for its usage in practice, and validate the measure’s performance in properly detecting selection bias. The three presented articles highlight the necessity to assess the sensitivity of estimates towards different assumptions about the missing-data and selection mechanism if it seems realistic that the ignorability assumption might be violated, and provide first solutions to enable such robustness checks for specific data situations.