Contributions in Merlin

Den Bedürfnissen schweizerischer KMU wird mit den Swiss GAAP FER ausdrücklich Rechnung getragen. Dazu gehört auch die Sicherstellung eines vernünftigen Kosten-/ Nutzen-Verhältnisses. Der Beitrag illustriert das Konzept der Swiss GAAP FER sowie der Kern-FER (Rahmenkonzept und Swiss GAAP FER 1–6).

One can be independent, or one can be subject to decisions made by others. This paper argues that this difference, embodied in the institutional distinction between the decision-making procedures ‘market’ and ‘hierarchy’, affects individual wellbeing beyond outcomes. Taking self-employment as an important case of independence, it is shown that the self-employed derive higher satisfaction from work than those employed in organizations, irrespective of income gained or hours worked. This is evidence for procedural utility: people value not only outcomes, but also the processes leading to outcomes.

For many kinds of capital, depreciation rates change systematically with the age of the capital. Consider an example that captures essential aspects of human capital, both regarding its accumulation and its depreciation: a worker obtains knowledge in period 0, then uses this knowledge in production in periods 1 and 2, and thereafter retires. Here, depreciation accelerates: it occurs at a 100% rate after period 2, and at a lower (perhaps zero) rate before that. The present paper analyzes the implications of non-constant depreciation rates for the optimal timing of taxes on capital income. The main finding is that under natural assumptions, the path of tax rates over time must be oscillatory. Oscillatory tax rates are optimal when depreciation rates accelerate with the age of the capital (as in the above example), and provided that the government can commit to the path of future tax rates but cannot apply different tax rates in a given year to different vintages of capital.

This thesis addresses the research objective to build an observable collaboration environment within the virtual world Second Life. By understanding the behavior of humans, the aim is to ultimately provide real-time support for virtual teams. Therefore, the central requirement for the environment is support for distributed team meetings, while providing mechanisms for data collection of those meetings at the same time. The work is based on certain theoretical foundations, as well as empirical findings, from collaborative work and virtual environments. In particular, the notions of media naturalness theory are assessed in Second Life. In order to test the suitability of the created virtual meeting environment for collaboration, a usability evaluation cycle frames the investigation. Several group trial experiments are conducted to elicit requirements for future applications of the environment. The observations inform the design of the environment for the next cycle. The collectable data from the trials comprises chat communication, avatar coordinates, screen-capture video and post-hoc interviews. The chat communication is coded and analyzed. The findings help us support or put into perspective observations made during the trial experiments. An outlook regarding the implications for practice, as well as potential research opportunities in virtual worlds conclude the work.

Although documents are an important part of everyday business, there is no satisfying solution to manage them. Documents contain information crucial to business. Until today, It is a unsolved challenge to extract desired information from the giant amount of documents produced. In oppisition to documents, other business data is highly structured an can be stored in databases. The storage in a database offers many advantages such as concurrent processing and optimized search. Thus it is desriable to use these features in document management. The new approach Pylonix offers an architecture an a data model to store complex documents in databases. A flexible and powerful query language TXQL (TeXt Query Language) is designed and discussed within the scope of this master thesis. This language is able to query and process all elements, information as well as metadata of documents. It allows complex and comprehensive queries of arbitrary elements of complex documents that are stored in Pylonix. Furthermore TXQL offers facilities to manipulate every Element of such a document.

Background: We recently reported the development of the AMIS (Acute Myocardial Infarction in Switzerland) risk stratification model for patients with acute coronary syndrome (ACS). This model predicts hospital mortality risk across the complete spectrum of ACS based on 7 parameters available in the prehospital phase. Since the AMIS model was developed on a Swiss dataset in which the majority of patients were treated by primary PCI, we sought validation on an external cohort treated with a more conservative strategy. Methods: The Krakow Region (Malopolska) ACS registry included patients treated with a non-invasive strategy in 29 hospitals in the greater Krakow (PL) area between 2002-2006. In-hospital mortality risk was calculated using the AMIS model (input parameters: age, Killip class, systolic blood pressure, heart rate, pre-hospital resuscitation, history of heart failure, and history of cerebrovascular disease; risk calculator available at www.amis-plus.ch). Discriminative performance was quantified as ""area under the curve"" (AUC, range 0–1) in a receiver operator characteristic, and was compared to the risk scores for ST-elevation myocardial infarction (STEMI) and Non-STE-ACS from the TIMI study group. Results: Among the 2635 patients included in the registry (57% male, mean age 68.2±11.5 years, 31% STEMI) hospital mortality was 7.6%. The AUC using the AMIS model was 0.842, compared to 0.724 for the TIMI risk score for STEMI or 0.698 for the TIMI risk score for Non-STE-ACS (Fig. A). Risk calibration was maintained with the AMIS model over the complete range of risks (Fig. B). The performance of the AMIS model in this cohort was comparable to that found in the AMIS validation cohort (n=2854, AUC 0.868). Conclusions: The AMIS risk prediction model for ACS displayed an excellent predictive performance in this non-invasively-treated external cohort, confirming the reliability of this bedside “point-of-care” model in everyday practice.

The goal of this thesis is the creation of a framework for the holistic collection, visualization and analysis of heterogeneous data of IT services. The framework is to enable a systematic, periodic automatic and manual data gathering on the one hand and a „big picture“ visualization of the past and present situation on the other hand. This visualization provides a basis to create group awareness of the current situation and helps to support decisionmaking and coordination in the group. The thesis describes the conceptual design of the framework and a prototypical implementation for a support team of a major swiss bank. The evaluation of the realisation provides insights about the practical adoption of the framework. The concluding evaluation of the findings leads to recommendations for the successful realisation of a comprehensive tool for the holistic collection and visualization of heterogeneous data.

Players repeatedly face a coordination problem in a dynamic global game. By choosing a risky action (invest) instead of waiting, players risk instantaneous losses as well as a loss of payoffs from future stages, in which they cannot participate if they go bankrupt. Thus, the total strategic risk associated with investment in a particular stage depends on the expected continuation payoff. High continuation payoff makes investment today more risky and therefore harder to coordinate on, which decreases today’s payoff. Thus, expectation of successful coordination tomorrow undermines successful coordination today, which leads to fluctuations of equilibrium behavior even if the underlying economic fundamentals happen to be the same across the rounds. The dynamic game inherits the equilibrium uniqueness of the underlying static global game.

Bereits zum fünften Mal treffen sich dieses Jahr Forscher aus Deutschland und den europäischen Nachbarländern, um unter dem Dach des "Workshop on Mobile Ad-hoc Networks" Erfahrungen und Forschungsergebnisse auszutauschen und neue Ideen zu diskutieren. Nachdem der WMAN 2002 als eigenständige Veranstaltung abgehalten wurde, folgten 2004 und 2005 Veranstaltungen unter dem Dach der GI Jahrestagungen in Ulm und Bonn. 2007 fand der WMAN Workshop dann als Workshop der Konferenz "Kommunikation in Verteilten Systemen (KiVS) 2007" in Bern statt. Für 2009 ist wieder geplant, einen KiVS- Workshop anzubieten. Um die Kontakte und Diskussionen in diesen zwei Jahren nicht abreißen zu lassen, bieten wir 2008 nun ein neues Format an: ein WMAN Fachgespräch. In der Ausrichtung und den Anforderungen an die Beiträge ist dieses deutlicher und flexibler als ein vollständiger Workshop. Primäres Ziel ist ein informeller Gedankenaustausch, der durch Vorträge und kurze Beiträge unterstützt wird, die in Form dieses technischen Berichtes veröffentlicht werden. Themen der diesjährigen Beiträge sind verschiedenste Aspekte mobiler Ad-hoc Netzwerke, angefangen von der Nutzung von VoIP in Mesh Netzen, Beiträgen zu taktischen Ad-hoc Netzwerken und VANETs bis hin zur Tool-Unterstützung.

In this paper, we formalize the problem of Basic Graph Pattern (BGP) optimization for SPARQL queries and main memory graph implementations of RDF data. We define and analyze the characteristics of heuristics for selectivity-based static BGP optimization. The heuristics range from simple triple pattern variable counting to more sophisticated selectivity estimation techniques. Customized summary statistics for RDF data enable the selectivity estimation of joined triple patterns and the development of efficient heuristics. Using the Lehigh University Benchmark (LUBM), we evaluate the performance of the heuristics for the queries provided by the LUBM and discuss some of them in more details. Note that the SPARQL versions of the 14 LUBM queries and the University0 data set we used in this paper can be downloaded from here.