Stefan Koch

Integrative Visual Analytics for Suspicious Behavior Detection (2009)

Bak, Peter, Koch, Stefan, Rohrdantz, Christian, Butscher, Simon, Leifert, Svenja, Jungk, Patrick, ...

In the VAST Challenge 2009 suspicious behavior had to be detected applying visual analytics to heterogeneous data, such as network traffic, social network enriched with geo-spatial attributes, and...

Sourcing decisions in the finance sector: current state and focus on economies of scale and knowledge management (2008)

Stefan Koch

In this paper we will analyse sourcing decisions in the finance sector, dealing with a mature area, IT outsourcing and a relatively new field, operations outsourcing. For introducing this topic, we...

Sourcing decisions in the finance sector: current state and focus on economies of scale and knowledge management (2008)

Stefan Koch

In this paper we will analyse sourcing decisions in the finance sector, dealing with a mature area, IT outsourcing and a relatively new field, operations outsourcing. For introducing this topic, we...

ABSTRACT COOPERATION AND DISRUPTIVE BEHAVIOUR – LEARNING FROM A MULTI-PLAYER INTERNET GAMING COMMUNITY (2008)

Michael Hahsler, Stefan Koch

In this paper we report possibilities and experiences from employing Counter-Strike, a popular multi-player Internet computer game and its resulting online community in research on cooperative...

Seminar paper draft Seminar aus Informationswirtschaft (2008)

Christoph Olbrich, Dr. Stefan Koch

The demand for internet content rose dramatically in recent years. Servers became more and more powerful and the bandwidth of end user connections and backbones grew constantly during the last...

Using Value-at-Risk for IS/IT Project and Portfolio Appraisal and Risk Management (2008)

Stefan Koch

Abstract: This paper makes the case for adopting a risk measure from the finance sector for IS/IT project and portfolio evaluation. The proposed value-at-risk approach constitutes a well-tested...

Differences in Characteristics of the ERP System Selection Process between Small or Medium and Large Organizations (2007)

Edward Bernroider, Stefan Koch

In this paper we detail the results from an empirical study concerning differences in characteristics of the ERP system selection process between small or medium and large sized organizations. In...

ABSTRACT COOPERATION AND DISRUPTIVE BEHAVIOUR – LEARNING FROM A MULTI-PLAYER INTERNET GAMING COMMUNITY (2007)

Michael Hahsler, Stefan Koch

In this paper we report possibilities and experiences from employing Counter-Strike, a popular multi-player Internet computer game and its resulting online community in research on cooperative...

Open Source software engineering –- The state of research (2007)

Stefan Koch

The following commentary is part of First Monday's Special Issue #2: Open Source.

Entwicklung und Evaluation einer berufsbezogenen Gruppentherapie für die stationäre kognitive Verhaltenstherapie (2007)

Koch, Stefan

Entwicklung und Evaluation einer berufsbezogenen Gruppentherapie für die stationäre kognitive Verhaltenstherapie.

Managing Assistant and Contact: (2007)

Stefan Strecker, Stefan Koch, Der Wirtschaftsinformatik, Ulrich Frank, Stefan Strecker, ...

der Darstellung vorläufiger Ergebnisse, die i. d. R. noch für spätere Veröffentlichungen überarbeitet werden. Die Autoren sind deshalb für kritische Hinweise dankbar. Alle Rechte vorbehalten....

High-Reynolds-Number Design of a Wing Section Including Control of Boundary Layer Properties (2006)

Richter, Kai, Koch, Stefan, Rosemann, Henning

A novel high Reynolds number design for airfoils with an application in the outer part of a modern transport aircraft wing was conducted within the frame of the German technology research programme...

Ergebnisse eines empirischen Usability-Vergleichs von Open und Closed Source Office Paketen anhand von Microsoft Office und OpenOffice.org (2006)

Koch, Stefan, Olbrich, Christoph

In diesem Artikel werden die Ergebnisse einer vergleichenden Usability-Untersuchung von Office Suites dargestellt, wobei einerseits der kommerzielle Marktführer Microsoft Office, andererseits die in...

Ergebnisse eines empirischen Usability-Vergleichs von Open und Closed Source Office Paketen anhand von Microsoft Office und OpenOffice.org (2006)

Koch, Stefan; Olbrich, Christoph

In diesem Artikel werden die Ergebnisse einer vergleichenden Usability-Untersuchung von Office Suites dargestellt, wobei einerseits der kommerzielle Marktführer Microsoft Office, andererseits die in...

Conceptual Modelling as a New Entry in the (2006)

Bazaar The Open, Stefan Koch, Stefan Strecker, Ulrich Frank

The present contribution proposes to transfer the main principles of open source software development to a new context: conceptual modelling; an activity closely related to software development.

Biomechanische Untersuchungen zur Stabilität verschiedener Osteosynthesematerialien bei Gelenkwalzenfrakturen vom Typ A (2005)

Koch, Stefan

Bei Gesichtsschädelverletzungen stellen Unterkieferfrakturen einen hohen Anteil dar. Besonders problematisch sind dabei Frakturen der Gelenkwalze, die bei der bisher üblichen konservativen Therapie...

Pflanzenkläranlagen : eine ökologische verantwortungsvolle Abwasserentsorgung. Grundlagen, Standortvergleiche, Langzeitverhalten (2005)

Koch, Stefan

Ziel der Arbeit war die Beurteilung dieser dezentralen Abwasserbehandlung im Laufe der Zeit. Um der Fragestellung nach etwaigen Problemsituationen nachzugehen, beginnt die Arbeit zunächst mit einem...

Effort Modeling and Programmer Participation in Open Source Software Projects (2005)

Koch, Stefan

This paper analyses and develops models for programmer participation and effort estimation in open source software projects. This has not yet been a centre of research, although any results would be...

Effort Modeling and Programmer Participation in Open Source Software Projects (2005)

Koch, Stefan

This paper analyses and develops models for programmer participation and effort estimation in open source software projects. This has not yet been a centre of research, although any results would be...

Discussion of a large-scale open source data collection methodology (2005)

Michael Hahsler, Stefan Koch

This paper discusses in detail a possible methodology for collecting repository data on a large number of open source software projects from a single project hosting and community site. The process...

Advisors (2005)

Ausgeführt Am, Dr. Stefan Koch, Ingo Feinerer, Wolfgang Janko, Stefan Koch

deren Nutzen in der Softwareentwicklung darlegt, als Grundlage verwendet und um wesentliche betriebswirtschaftliche Komponenten erweitert, die eine

Evolution of Open Source Software Systems – A Large-Scale Investigation (2005)

Stefan Koch

Abstract – In this paper, the evolution of a large sample of open source software projects will be analysed. The evolution of commercial systems has been an issue that has long been a center of...

Profiling an Open Source Project Ecology and Its Programmers (2004)

Stefan Koch

While many successful and well-known open source projects produce output of high quality, a general assessment of this development paradigm is still missing. In this paper, an online community of...

Profiling an Open Source Project Ecology and Its Programmers (2004)

Stefan Koch

While many successful and well-known open source projects produce output of high quality, a general assessment of this development paradigm is still missing. In this paper, an online community of...

Zeitliche und räumliche Turbulenzentwicklung in einem Rohrwindkanal und deren Einfluss auf die Transition an Profilmodellen (2004)

Koch, Stefan

Im Kryo-Rohrwindkanal Göttingen (KRG) wurden Strömungsqualitätsmessungen durchgeführt, in denen die zeitliche und räumliche Entwicklung einzelner Schwankungsgrößen untersucht wurde. Hierbei...

Remote Analysis and Measurement of Libre Software Systems By Means of the CVSAnalY tool (2004)

Gregorio Robles, Stefan Koch, Juan Carlos

Libre (free, open source) software is one of the paradigmatic cases where heavy use of telematic tools and userdriven software development are key points. This paper proposes a methodology for...

Adaptive Airfoil (2003)

Geißler, Wolfgang, Koch, Stefan

"Adaptive Airfoil" is the title of an EREA project launched in January, 1998 with the participation of CIRA, DLR, FFA (now FOI), INTA and ONERA. The main objective of the project is to demonstrate...

Bestimmung des Reflexionsverhaltens eines Spänestrals an einer festen Wand (2000)

Koch, Stefan

Um die Entwicklung und Konstruktion von Absaughauben für Holzbearbeitungsmaschinen wirtschaftlicher und effektiver zu gestalten, sollder Konstrukteur über ein Programm verfügen, das ihm das...

Results from software engineering research into open source development projects using public data (2000)

Koch, Stefan, Schneider, Georg

This paper presents first results from research into open source projects from a software engineering perspective. The research methodology employed relies on public data retrieved from the...

Results from software engineering research into open source development projects using public data (2000)

Koch, Stefan; Schneider, Georg

This paper presents first results from research into open source projects from a software engineering perspective. The research methodology employed relies on public data retrieved from the...

Bestimmung des Reflexionsverhaltens eines Spänestrals an einer festen Wand (2000)

Koch, Stefan

Um die Entwicklung und Konstruktion von Absaughauben für Holzbearbeitungsmaschinen wirtschaftlicher und effektiver zu gestalten, soll der Konstrukteur über ein Programm verfügen, das ihm das...

Results from Software Engineering Research into Open Source Development Projects Using Public Data, Wirtschaftsuniversitat (2000)

Stefan Koch, Georg Schneider

Abstract-This paper presents first results from research into open source projects from a software engineering perspective. The research methodology employed relies on public data retrieved from the...

Results from Software Engineering Research into Open Source Development Projects Using Public Data (2000)

Stefan Koch, Georg Schneider

This paper presents first results from research into open source projects from a software engineering perspective. The research methodology employed relies on public data retrieved from the...

Empirische Untersuchung der Entscheidungsfindung bei der Auswahl betriebswirtschaftlicher Standardsoftware in österreichischen Unternehmen (1999)

Bernroider, Edward, Koch, Stefan

In diesem Diskussionspapier wird die Entscheidungsfindung bei der Auswahl betriebswirtschaftlicher Standardsoftware mit Hilfe einer empirischen Studie untersucht. Zunächst wird anhand der...

Virtual Notes: Annotations on the WWW for Learning Environments (1999)

Andreas Geyer-schulz, Stefan Koch, Georg Schneider, Computer Science

This paper describes Virtual Notes, small yellow stickers which can be freely placed on instrumented HTML-pages using standard Internet technology. In a teaching and research environment they provide...

Decision Making for ERP-Investments from the Perspective of Organizational Impact - Preliminary Results from an Empirical Study (1999)

Edward Bernroider, Stefan Koch

This study addresses the complex relationship between decision making for ERP investments and the consideration of organizational impact under 2 different perspectives: Enterprise Resource Planning...

Using Weakest Precondition for Software Process Model Reuse (1999)

Stefan Koch

This paper describes a method to determine the possibility of combining two or more process models using an approach similar to the proof of (partial) correctness of algorithms by determining the...

K-band chipset for fully integrated point to multipoint microwave modules using 0.25 micron PHEMT MMIC technology (1998)

Koch, Stefan, Bischof, Werner, Gill, Hardial, Müller, Ulf

The high volume point to multipoint market demands lowest cost components for all building blocks of the system, particularly for the microwave circuits. Different types of MMICs, including frequency...

Untersuchung und Optimierung alternativer Zahnfüllungs-Composite-Materialien auf der Basis von Polybutadienepoxid [microform] / (1995)

Koch, Stefan.

Mikrofiche-Ausg.: Egelsbach ; Frankfurt (Main) ; St. Peter Port : Hänsel-Hohenhausen, 1995. 2 Mikrofiches.

The genetic organization of integrated hepatitis B virus DNA in the human hepatoma cell line PLC/PRF/5 (1984)

Koch, Stefan, Von Loringhoven, Arndt Freytag, Kahmann, Regine, Hofschneider, Peter Hans, Koshy, Rajen

Hepatitis B virus (HBV) DNA is often found integrated in the genome of infected human liver cells and is supposed to be related to the development of primary liver carcinoma (PLC). Four clones of HBV...

Exploring the Effects of Coordination and Communication Tools on the Efficiency of Open Source Projects using Data Envelopment Analysis (1970)

Stefan Koch

In this paper, we propose to explore possible benefits of communication and coordination tools in open source projects using data envelopment analysis (DEA), a general method for efficiency...

Data and analyses sharing to support research on free/libre open source software A Debate (1970)

Evangelia Berdou, Kevin Crowston, Greg Madey, Megan Conklin, Stefan Koch, Walt Scacchi

Research on FLOSS has relied on several different kinds of scientific evidence, such as the archives created by the FLOSS developers, versioned code repositories, mailing list messages and bug and...

Open Source Project Categorization Based on Growth Rate Analysis and Portfolio Planning Methods (1970)

Stefan Koch, Volker Stix

In this paper, we propose to arrive at an assessment and evaluation of open source projects based on an analysis of their growth rates in several aspects. These include code base, developer number,...

Conceptual Modelling as a New Entry in the Bazaar: The Open Model Approach (1970)

Stefan Koch, Stefan Strecker, Ulrich Frank

The present contribution proposes to transfer the main principles of open source software development to a new context: conceptual modelling; an activity closely related to software development. The...

Association of Csk to VE-cadherin and inhibition of cell proliferation

Baumeister, Ulf, Funke, Ruth, Ebnet, Klaus, Vorschmitt, Henrik, Koch, Stefan, Vestweber, Dietmar

Vascular endothelial cadherin (VE-cadherin) mediates contact inhibition of cell growth in quiescent endothelial cell layers. Searching for proteins that could be involved in VE-cadherin signaling, we...

Association of Csk to VE-cadherin and inhibition of cell proliferation

Baumeister, Ulf, Funke, Ruth, Ebnet, Klaus, Vorschmitt, Henrik, Koch, Stefan, Vestweber, Dietmar

Vascular endothelial cadherin (VE-cadherin) mediates contact inhibition of cell growth in quiescent endothelial cell layers. Searching for proteins that could be involved in VE-cadherin signaling, we...

Sourcing decisions in the finance sector: current state and focus on economies of scale and knowledge management

Stefan Koch

In this paper we will analyse sourcing decisions in the finance sector, dealing with a mature area, IT outsourcing and a relatively new field, operations outsourcing. For introducing this topic, we...

Effort modeling and programmer participation in open source software projects

Koch, Stefan

This paper develops models for programmer participation and effort estimation in open source software projects and employs the results to assess the efficiency of open source software creation....

Non-Muscle Myosin IIA Differentially Regulates Intestinal Epithelial Cell Restitution and Matrix Invasion

Babbin, Brian A., Koch, Stefan, Bachar, Moshe, Conti, Mary-Anne, Parkos, Charles A., Adelstein, Robert S., ...

Epithelial cell motility is critical for self-rejuvenation of normal intestinal mucosa, wound repair, and cancer metastasis. This process is regulated by the reorganization of the F-actin...