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.
Ever fiercer competition has forced enterprises not only to optimize their own operations but also to cooperate with their suppliers and customers along their supply chains. Thus, competition today usually takes place between supply chains and not between individual enterprises. Business-To-Business integration (B2Bi) is a major task of supply chain management (SCM), and although it already has been researched for years, B2Bi is still an area of active research with a plethora of research questions and according approaches. Hence, management of B2Bi projects necessitates the identification of relevant requirements which is a far from trivial task. This paper identifies a core set of B2Bi challenges and deduces a comprehensive set of B2Bi requirements that are particularly useful for tackling the challenges identified. The derivation of B2Bi requirements follows an inductive approach that is based on the analysis of integration standards, reference architectures and related literature. In order to operationalize the B2Bi requirements for further analysis and concrete B2Bi projects, the requirements are classified according to the abstraction layers of a B2Bi schema. Thus, this report not only offers a requirements check list for B2Bi projects but also helps in deciding when to address which requirements during the course of a B2Bi project.
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.
Inductive programming is concerned with the automated construction of declarative, often functional, recursive programs from incomplete specifications such as input/output examples. The inferred program must be correct with respect to the provided examples in a generalising sense: it should be neither equivalent to them, nor inconsistent. Inductive programming algorithms are guided explicitly or implicitly by a language bias (the class of programs that can be induced) and a search bias (determining which generalised program is constructed first). Induction strategies are either generate-and-test or example-driven. In generate-and-test approaches, hypotheses about candidate programs are generated independently from the given specifications. Program candidates are tested against the given specification and one or more of the best evaluated candidates are developed further. In analytical approaches, candidate programs are constructed in an example-driven way. While generate-and-test approaches can -- in principle -- construct any kind of program, analytical approaches have a more limited scope. On the other hand, efficiency of induction is much higher in analytical approaches. Inductive programming is still mainly a topic of basic research, exploring how the intellectual ability of humans to infer generalised recursive procedures from incomplete evidence can be captured in the form of synthesis methods. Intended applications are mainly in the domain of programming assistance -- either to relieve professional programmers from routine tasks or to enable non-programmers to some limited form of end-user programming. Furthermore, in the future, inductive programming techniques might be applied to further areas such as supporting the inference of lemmata in theorem proving or learning grammar rules. Inductive automated program construction has been originally addressed by researchers in artificial intelligence and machine learning. During the last years, some work on exploiting induction techniques has been started also in the functional programming community. Therefore, the third workshop on |Approaches and Applications of Inductive Programming| took place for the first time in conjunction with the ACM SIGPLAN International Conference on Functional Programming (ICFP 2009). The first and second workshop were associated with the International Conference on Machine Learning (ICML 2005) and the European Conference on Machine Learning (ECML 2007). AAIP´09 aimed to bring together researchers from the functional programming and the artificial intelligence communities, working in the field of inductive functional programming, and advance fruitful interactions between these communities with respect to programming techniques for inductive programming algorithms, the identification of challenge problems and potential applications. For everybody interested in inductive programming we recommend to visit the website: www.inductive-programming.org.
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.
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.