Contributions in Merlin

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In this article, decomposition methods for two‐stage linear recourse problems with a finite discrete distribution are discussed. First, we cover the L‐shaped decomposition method which represents a breakthrough concerning numerically efficient methods for solving two‐stage recourse problems. This algorithm was the basis for the development of several other decomposition methods. After giving an overview of these algorithms, we present regularized decomposition and stochastic decomposition in a more detailed fashion. Variance for recourse‐constrained problems and special cases including simple recourse with a random technology matrix are also considered. With reference to stochastic decomposition, the scope of which is not restricted to finite discrete distributions, algorithms for the continuous‐distribution case are discussed briefly with references to the literature.

Over the last few years research on management consulting has established itself as an important area in management studies. While, traditionally, consulting research has been predominantly a-theoretical, lately researchers have been calling for an exploration of different theoretical approaches. This article has been written in response to these calls. It explores a new perspective for theorizing the client–consultant relationship based on the theory of social systems by Niklas Luhmann. According to this approach, clients and consultants can be conceptualized as two autopoietic communication systems that operate according to idiosyncratic logics. They are structurally coupled through a third system, the so-called ‘contact system’. Due to the different logics of these systems, the transfer of meaning between them is not possible. This theoretical position has interesting implications for the way we conceptualize consulting, challenging many traditional assumptions. Instead of supporting the client in finding solutions to their problems, this perspective emphasizes that consulting firms can only cause ‘perturbations’ in the client’s communication processes, inducing the client system to construct its own meaning from it.

These theses document the working process of a database constructive web application with name Swiss Feed Database System, Version 2.0. One major point is hereby the inclusion of geographical information such as address specifications and the procedure to display the resulting locations usefully on a map. Next to a short introduction into the topic of Geographical Information System (GIS), a tutorial in embedding Google Maps will mostly cover that theme. Furthermore, the construction of an interactive web page by using a PostgreSQL database, PHP server scripts and JavaScript along with its Asynchronous JavaScript and XML (Ajax) object is part of this documentation.

Reliable defect predictions enable a better management of the software developerís effort during the process of software engineering. The identified bug-prone parts can be reengineered or tested with special care. However, defect prediction works only if enough data is available to learn the prediction models. If the data is not sufficient, prediction models of other projects can be applied. Traditional cross-project defect predictions achieve superficial results. That is why we propose a completely new approach. Based on the collaborative filtering framework RECOMIZER, we predict post-release defects of 19 Eclipse plug-ins. Therefore we measure the similarities between the prediction models derived from the different projects. Combining the defect models with the highest similarity to the model of the project under investigation, we perform cross-project defect prediction based on collaborative filtering. We are able to confirm our main hypothesis, that the performance of the defect predictions based on collaborative filtering outperforms the predictions we did while considering the model of the project under investigation only. We achieve a promising mean AUC of 0.745 using a Naive Bayes classifier. In the case of a J48 decision tree, we achieve a mean AUC of 0.734. We also analyze the similarities of the different defect models. The projects organized after their model similarity, rather build a clew than the expected clusters.

Studies have shown that a number of bank's clients are not satisfied with the current manner of consultation. The insufficient transparency and the predominant asymmetry of information between the consultant and the client get criticized often. A device for investment consultation on the basis of a touch-sensitive table was developed at the Department of Information Technology at the University of Z¸rich. In this paper, the findings and insights of this electronic solution are being applied to develop an additional solution, a tablet PC. In a series of experiments the differences and advantages of the two devices are being analyzed in order to derive recommendations about the manner in which these devices can be integrated in the process of consultation, and if one of the devices is better suited than the other.

Programming is a very important competence in Computer Science education. However, many research studies such as in (Jenkins T. , 2002), (Kölling, 1999), (Bonnar & Soloway, 1985) and (Ala-Mutka, 2003) report from great difficulties in programming education. A focus group also exposed several difficulties of Computer Science students at the University of Zurich. Students expressed a need for more feedback and easier access for support while programming. A student reported that “learning programming is a try and error where you sometimes don’t realize the error”. This work addresses methods how students can through discussion and feedback with others. Methods were applied to web-based prototypes. Main motivation behind the prototypes is to increase collaboration among learners and their involvement into the learning process in an informal context. The creation of an informal context is given by enabling students to contribute to discussions through different information channels. Information flows from these channels together to a single information web cloud named discussIT. Contribution to these channels isn’t compulsory and has no direct connection to any programming course. Consequently, the prototypes aim to extend the learner’s social, information and neural networks.

It has been nearly 50 years since the appearance of the pioneering paper of Mandelbrot (1963) on the non-Gaussianity of financial asset returns, and their highly fat-tailed nature is now one of the most prominent and accepted stylized facts. The recent book by Jondeau et al. (2007) is dedicated to the topic, while other chapters and books discussing the variety of non-Gaussian distributions of use in empirical finance include McDonald (1997), Knight and Satchell (2001), and Paolella (2007).

This assignment is about the development of a system to use mobile devices as data collectors for social science applications. Subjects are the collection, processing, visualization and exporting of various data types. A special focus is set on the collection of geographic data through GPS modules of mobile devices and protecting the privacy of this critical information. An introduction is given to the concepts of social science that have to be modeled, possible software architectures and web service approaches for the implementation of the framework, protocols and specifications to ensure the security of the system and algorithms to protect the privacy of the collected data. Further, concepts to analyze geographic data are stated. Discussed privacy algorithms and concepts are k-anonymity, uncertainty-aware path cloaking, hitchhiking and truncation. For the analysis of coordinates, the k-means algorithm is described. The development process is documented throughout the definition of functional and non-functional requirements for the system, creating the design and concept of the database structure, the server component as well as the client component according to this requirements and the actual implementation of the system. A service-oriented web service using SOAP and a client application based on Android were finally implemented.

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