In den vergangenen Jahren ist die Verbreitung von mobilen Geräten mit integrierter Lokalisierungstechnologie (z.B. GPS) stark gestiegen. Jeder, der ein solches Gerät besitzt, kann zum Datenlieferanten werden und in einem Netzwerk von Freiwilligen, die Rolle eines Datensensors übernehmen. In der vorliegenden Dissertation werde ich zwei Problemstellungen näher betrachten, die im Kontext von raumbezogenen Daten, erhoben von Gemeinschaften aus fachlich (hier: geowissenschaftlich) nicht geschulten Nutzern, noch ungelöst sind: Wie können geowissenschaftliche Laien motiviert werden, freiwillig qualitätsgesicherte raumbezogene Daten zu erheben? Der erste Beitrag meiner Dissertation liefert eine Antwort auf diese Frage. Er beinhaltet ein Framework zum Design von ortsbezogenen Spielen, die geowissenschaftliche Laien motivieren, raumbezogene Daten qualitätsgesichert in spielerischer Art und Weise zu sammeln. Um es mit den Worten von Peltola et al. (2006) auszudrücken: ”game play is a natural motivator to participate in something that is not necessary or beneficial. [...] By controlling game events and perhaps game logics and rules, the agencies that ultimately use the gathered data, can steer players to do tasks supporting their needs“. Wie kann die Qualität von Sammlungen semantisch angereicherter raumbezogener Daten verbessert werden? Eine wichtige Eigenschaft von ortsbezogenen Spielen zur Datenerhebung ist die wiederholte Spielbarkeit. Im Gegensatz zu anderen Domänen ist nämlich die Erstellung redundanter Daten im raumbezogenen Kontext sogar erwünscht. Das Zusammenführen von Daten mehrerer Nutzer kann man als Mehrfachmessung auffassen, die sich dazu nutzen lässt, die Qualität von Lokalisierung (Wo?) und Kategorisierung (Was?) zu verbessern. Der zweite Beitrag meiner Dissertation gibt eine Antwort auf die Fragestellung und besteht in einem Ansatz zur semantischen Integration der gesammelten raumbezogenen Daten.
Globalization and rapid technological change elevates the role of the Internet in terms of business service offering and procurement. At the same time, companies specialize on core competencies on the one hand, and on the other hand, integrate with other firms into “service ecosystems” in order to serve market needs in a flexible manner. One challenge in this setting is how to develop and describe novel business services within service ecosystems for efficient trade in services over the Internet. This work proposes a method for describing business services that integrates into business service development processes. The development of such a method leads to three major challenges: Firstly, it is necessary to determine which properties are appropriate for describing business services. This work analyzes existing approaches in the marketing, information systems, and computer science domain and develops a model for a formal description that facilitates offering and discovering of business services. Secondly, business service description elicitation, documentation, and communication must be provided for the whole business service development process. This work’s approach includes the development of an appropriate modeling notation as an extension of the Unified Modeling Notation (UML). Thirdly, there is a need for transforming business service descriptions into software realization languages that are suitable for the Internet. This contribution offers an automatic transformation of business service descriptions into Web Services Description Language (WSDL) documents using model-to-model transformation scripts. The method for describing business services was evaluated by implementing an integrated modeling environment along with related transformation scripts as well as by two case studies in the insurance and IT outsourcing industry.
Orchestration languages are of paramount importance for building composite services in service-oriented architectures. Pattern-based analysis is a method that allows to determine the expressiveness of existing process languages and serves as a means of comparison between different languages. The aim of this study is the analysis and comparison of important languages for building Web Services-based orchestrations, as well as the improvement of the method of pattern-based analysis. The predominant orchestration language today is the Web Services Business Process Execution Language (WS-BPEL) 2.0. This language is a standard that has been implemented by several companies and projects, such as the OpenESB BPEL Service Engine. An additional language is Windows Workflow 4 that is shipped by Microsoft as part of the .NET framework. There are various aspects, represented by pattern catalogs, for which existing languages can be analyzed. This study suggests a methodology for ordering existing pattern catalogs according to their importance for a selected problem domain which is Business-to-Business Integration. It furthermore presents an extensive evaluation of the languages at hand and assesses the degree of support they provide for several of the most important pattern catalogs. These catalogs are the workflow control-flow patterns, the service interaction patterns, the change patterns and the time patterns.
Inductive functional programming systems can be characterised by two diametric approaches: Either they apply exhaustive program enumeration which uses input/output examples (IO) as test cases, or they perform an analytical, data-driven structural generalisation of the IO examples. Enumerative approaches ignore the structural information provided with the IO examples, but use type information to guide and restrict the search. They use higher-order functions which capture recursion schemes during their enumeration, but apply them randomly in a uninformed manner. Analytical approaches on the other side heavily exploit this structural information, but have ignored the benefits of a strong type system so far and use only recursion schemes either fixed and built in, or selected by an expert user. In category theory universal constructs, such as natural transformations or type morphisms, describe recursion schemes which can be defined on any inductively defined data type. They can be characterised by specific universal properties. Those type morphisms and related concepts provide a categorical approach to functional programming, which is often called categorical programming. This work shows how categorical programming can be applied to Inductive Programming and how universal constructs, such as catamorphisms, paramorphisms, and type functors, can be used as recursive program schemes for inductive functional programming. The use of program schemes for Inductive Programming is not new. The special appeal and novelty of this work is that, contrary to previous approaches, the program schemes are neither fixed, nor selected by an expert user: The applicability of those recursion schemes can be automatically detected in the given IO examples of a target function by checking the universal properties of the corresponding type morphisms. Applying this to the analytical system Igor2, both the capabilities and the expressiveness can be extended without a decrease in efficiency. An extension of the analytical functional inductive programming system Igor2 is proposed and its algorithms described. An empirical evaluation demonstrates the improvements with respect to efficiency and effectiveness that can be achieved by the use of type morphisms for Igor2 due to a reduction in search space complexity.
Im Servicegeschäft werden Eventkorrelationssysteme verwendet, um bevorstehende Systemzustände vorherzusagen und damit Anlagenausfälle zu vermeiden. Aus strategischer Sicht kann dies zu höherer Anlagenverfügbarkeit und bessere Planbarkeit beitragen. Unternehmen, die von diesem Wettbewerbsvorteil profitieren wollen, begegnen dabei häufig zwei grundlegenden Problemen: die Komplexität im Service steigt mit der Anzahl der Korrelationen. Gleichzeitig geht die Kostentransparenz für den Gesamtprozess verloren. Die vorliegende Arbeit zeigt, warum diese beiden Probleme entstehen und wie sie weitgehend vermieden werden können.
Der Erst- und speziell der Rückversicherungsmarkt sind seit einigen Jahren stark im Umbruch. Zunehmender Wettbewerb, Fusionen und Übernahmen sowie eine zunehmende Konvergenz von Kapital- und Versicherungsmärkten verändern die Märkte. Gleichzeitig hat die Versicherungswirtschaft deutlich zunehmende Schäden besonders durch Naturkatastrophen zu bewältigen. Neben diesen zentralen Veränderungen haben auch Besonderheiten des Versicherungsgeschäfts zum Aufkommen des so genannten „Alternativen Risiko Transfers“ – kurz ART – beigetragen. Mittlerweile wurden einige Arbeiten zum Thema ART verfasst. Hier sei exemplarisch auf Eickstädt (2001), Kellermann (2001), Banks (2004) oder Culp (2006) verwiesen. Ziel der hier vorgelegten Arbeit ist eine Darstellung unterschiedlicher Produkte, die dem ART zugeordnet werden, insbesondere aber deren Bewertung aus gesamtwirtschaftlicher Sicht, da dieser Blickwinkel bisher fehlte. Ferner werden Probleme, die im Zusammenhang mit speziellen Versicherungsunternehmen mit Sitz in Steueroasen einhergehen, thematisiert, sowie ausgewählte Aspekte der Bilanzierung bestimmter Versicherungsverträge erläutert.
The present work analyses decision making behaviour in personnel selection. The analysis focuses on the investigation of the relative importance of particular characteristics of the applicant on his or her hirability (applicant competencies, person-organisation and person-job fit, and social capital). Furthermore, it is analysed how firm size and age moderate this relative importance and in how far decision makers possess insight into their own decision making behaviour. The work is structured as follows: In the first chapter, the research topic is introduced, its importance and research gaps are described and the research approach is laid out. Furthermore, a literature review (chapter 2) provides a brief overview of the literature written on staffing in small and / or emerging firms. In chapter 3, I will elaborate that personnel selection is basically a decision making process with three major components: decision cues, criteria, and predictors. The description of selection theory with the interaction of criteria and predictors in the process of predicting future job performance of the applicant as well as a brief overview of selection practices with a vast number of potential decision cues leads to the next chapter. Chapter 4 presents an excursus in this thesis. As the findings of the previous chapter created a particular tension between theory and practice, an empirical pilot investigation was conducted to close that gap and to reconcile both theory and practice. Five case studies in emerging German IT and high-tech companies shed light on the elements to focus on in further research. These case studies also help to reconcile the theory of personnel selection with the special aspects of selection in the IT-context which is the particular focus industry of this thesis. In chapter 5, I continue with laying out the theory of personnel selection and close the theoretical part. I analyse the role and impact of three sets of decision cues: applicant competencies, applicant-organisation fit and applicant networks. This chapter is closed with the generation of a number of hypotheses on the use and importance of these decision cues in personnel selection in emerging high-technology firms. The third part of this thesis describes the empirical research undertaken to further investigate decision making in selection situations and to test the hypotheses. Chapter 6 introduces conjoint analysis as an appropriate means to capture decision policies and to answer the research questions. Variables, research instrument, and research approach are presented. The results of the described experimental survey are laid out in the following chapter 7. After the sample has been described, the data collected is analysed and presented and the hypotheses are tested. The fourth and final part of this thesis comprises the conclusion. In the last chapter, the results are discussed in the light of the previously laid out theory. Both limitations of the study as well as hints for future research are presented.
The so-called 'healthy immigrant effect' (HIE) is one of the most striking findings concerning immigrants and their health status. It is usually said to consist of two parts: According to the first part, immigrants upon arrival are on average healthier than their native peers. This finding is mostly explained by self-selection among their origin population. The idea is that healthier individuals are more likely to migrate as they are more able to reap the reward of the investment ‘migration’ than less healthy individuals. However, according to the second part, this health gap between immigrants and natives closes after a relatively short period of time, and the health of immigrants is converging to that of the natives or is getting even worse. This gradient of immigrants’ health has been found in many countries (e.g., Australia, Canada, and the United States) and for many different measures of health (e.g., self-rated health, chronic diseases). The causes for this decline in immigrants’ health are subject to ongoing research, but the underlying processes are not yet fully understood. In literature, several different explanations are discussed: The adoption of destination-country habits and lifestyles, the structural and material relationship between a low socio-economic status and poor health, additional stress due to the migration process, persistent barriers to access to health care due to cultural or language factors, as well as a kind of 'statistical artefact' due to selection effects caused by return migration. As health is a rather complex concept, one can assume that none of the proposed explanations can solely explain the decline in immigrants’ health, but rather that the health deterioration is a result of different interacting causes. This thesis investigates three of the proposed possible explanations for a decline in immigrants’ health, namely return migration, the adoption of destination-country habits and lifestyles, and immigrants’ access to health care and utilisation of health care services.
Die Geschäftsprozessmodellierung hat sich in der Praxis als Grundlage für die Ableitung fachlicher Anforderungen an betriebliche Anwendungssysteme weitgehend etabliert. Die anschließende Übertragung der fachlichen Modelle auf eine software-technische Implementierungsplattform bedeutet hingegen häufig einen methodischen Bruch und ist daher sehr aufwändig sowie komplex. Eine software-technische Implementierungsplattform, deren Konzepte sich an den Fachkonzepten der Geschäftsprozessmodellierung orientieren, kann diesen Übergang vereinfachen und die Systementwicklungsaufgabe hinsichtlich Aufwand und Komplexität deutlich verringern. Die vorliegende Arbeit beschreibt die Konzeption und Realisierung eines Software-Frameworks als flexible Basismaschine für die Entwicklung betrieblicher Anwendungssysteme auf Basis der SOM-Methodik. Das Framework bietet ausgehend von den fachlichen Modellen des Anwendungssystems anwendungsneutrale Software-Komponenten zu dessen vollständiger software-technischer Abbildung.
During the last decades, information technology has been characterized by constantly increasing performance of available hardware resources. This development allows the assignment of more and more complex tasks to software systems while at the same time leading to a massive increase of inherent complexity of applied systems. The expected further increase of complexity in the future demands for an explicit addressing of complexity. The concept of Component Orientation represents an approach for complexity reduction during the development and configuration of software through functional decomposition. With the vision of Autonomic Computing there does exist an approach for addressing complexity during the operation and maintenance of software systems. In this context, the approach is based on the idea of assigning low level-management tasks to the managed system itself. The concept of Component Orientation leads to the establishment of system architectures out of clearly distinguishable building blocks. Therefore, Component Orientation seems to provide a promising foundation for realizing the vision of Autonomic Computing. This thesis presents a realistic infrastructure for the autonomic management of component-based enterprise systems. The application area of such systems leads to special requirements for managed systems and is highly affected by the complexity problem. As a foundation for the proposed approach, a well established component standard was chosen to guarantee the practical relevance of applied concepts and techniques. The applied standard is Enterprise JavaBeans, version 3.0. The proposed infrastructure is designed and realized in a generic fashion. It provides a platform upon which solutions for different application areas of Autonomic Computing can be realized. Autonomic entities are supported through a programming interface which represents a system on three interrelated levels and allows its management: On the top-level, the underlying software of a managed system is considered. The middle layer addresses the system architecture. Runtime interactions within the system are represented on the lowest layer. On this foundation, a system can be managed in a holistic, model-based way. The runtime management of a system is enabled through a specially developed component which must be integrated into the affected environment. This component is compliant with the applied component standard and does not require any adjustment of the underlying component platform. Finally, a tool is provided which supports the establishment of manageability through the automated execution of required adjustments of components. The management of a system is realized transparently for its constituent elements during runtime. On the whole, the development of enterprise software is not affected by a potential application of the presented infrastructure.