Jörg Cassens

[Cas08]

Jörg Cassens. Explanation Awareness and Ambient Intelligence as Social Technologies. Guest Lecture, German Research Center for Artificial Intelligence (DFKI), Kaiserslautern, Germany, September 2008.

[Cas06b]

Jörg Cassens. Explanation and Context. Invited Talk, International Workshop on Case-Based Reasoning and Context Awareness (CACOA) at ECCBR 2006, September 2006.
[ bib ]

[Cas06a]

Jörg Cassens. Aspects of Uncertainty. Invited Talk, Workshop on Uncertainty and Fuzziness in Case-Based Reasoning at ECCBR 2006, September 2006.
[ bib ]

2009

[KPWC09]

Anders Kofod-Petersen, Rebekah Wegener, and Jörg Cassens. Closed Doors -- Modelling Intention in Behavioural Interfaces. In Anders Kofod-Petersen, Helge Langseth, and Odd Erik Gundersen, editors, Proceedings of the Norwegian Artificial Intelligence Society Symposium (NAIS 2009). To appear.

@InProceedings{Kofod-Petersen-Wegener-Cassens-NAIS-09, author = {Anders Kofod-Petersen and Rebekah Wegener and J\"{o}rg Cassens}, title = {Closed Doors -- Modelling Intention in Behavioural Interfaces}, booktitle = {Proceedings of the Norwegian Artificial Intelligence Society Symposium ({NAIS} 2009)}, year = 2009, editor = {Anders Kofod-Petersen and Helge Langseth and Odd Erik Gundersen}, note = {To appear} }

2008

[Cas08]

Jörg Cassens. Explanation Awareness and Ambient Intelligence as Social Technologies. Thesis for the degree doctor scientiarum, Norwegian University of Science and Technology, Trondheim, Norway, May 2008.
[ info | pdf 3.2MB ]

This work focuses on the socio-technical aspects of artificial intelligence, namely how (specific types of) intelligent systems function in human workplace environments. The goal is first to get a better understanding of human needs and expectations when it comes to interaction with intelligent systems, and then to make use of the understanding gained in the process of designing and implementing such systems.

The work presented focusses on a specific problem in developing intelligent systems, namely how the artefacts to be developed can fit smoothly into existing socio-cultural settings. To achieve this, we make use of theories from the fields of organisational psychology, sociology, and linguistics. This is in line with approaches commonly found in AI. However, most of the existing work deals with individual aspects, like how to mimic the behaviour or emulate methods of reasoning found in humans, whereas our work centers around the social aspect. Therefore, we base our work on theories that have not yet gained much attention in intelligent systems design. To be able to make them fruitful for intelligent systems research and development, we have to adapt them to the specific settings, and we have to transform them to suit the practical problems at hand.

The specific theoretical frameworks we draw on are first and foremost activity theory and to a lesser degree semiotics. Activity theory builds on the works of Leont'ev. It is a descriptive tool to help understand the unity of consciousness and activity. Its focus lies on individual and collective work practise. One of its strengths, and the primary reason for its value in AI development, is the ability to identify the role of material artefacts in the work process. Halliday's systemic functional theory of language (SFL) is a social semiotic theory that sets out from the assumption that humans are social beings that are inclined to interact and that this interaction is inherently multimodal. We interact not just with each other, but with our own constructions and with our natural world. These are all different forms of interaction, but they are all sign processes.

Due to the obvious time and spatial constraints, we cannot address all of the challenges that we face when building intelligent artefacts. In reducing the scope of the thesis, we have focused on the problem of explanation, and here in particular the problem of explanation from a user perspective. By putting social theories to work in the field of artificial intelligence, we show that results from other fields can be beneficial in understanding what explanatory capabilities are needed for a given intelligent system, and to ascertain in which situations an explanation should be delivered. Besides lessons learned in knowledge based system development, the most important input comes from activity theory.

The second focus is the challenge of contextualisation. Here we show that work in other scientific fields can be put to use in the development of context aware or ambient intelligent systems. Again, we draw on results from activity theory and combine this with insights from semiotics.

Explanations are themselves contextual, so the third challenge is to explore the space spanned by the two dimensions ability to explain and contextualisation. Again, activity theory is beneficial in resolving this issue.

The different theoretical considerations have also led to some practical approaches. Working with activity theory helps to better understand what the relevant contextual aspects of a given application are and helps to develop models of context which are both grounded in the tradition of context aware systems design and are plausible from a cognitive point of view.

Insights from an analysis of research in the knowledge based system area and activity theory have further lead to the amendment of a toolbox for requirements engineering, so called problem frames. New problem frames that target explanation aware ambient intelligent systems are presented. This is supplemented with work looking at the design of an actual system after the requirements have been elicited and specified. Thus, the socio-technical perspective on explanations is coupled with work that addresses knowledge representation issues, namely how to model sufficient knowledge to be able to deliver explanations.

@PhdThesis{Cassens-PhD-08, author = {J{\"o}rg Cassens}, title = {Explanation Awareness and Ambient Intelligence as Social Technologies}, school = {Norwegian University of Science and Technology}, year = {2008}, type = {Thesis for the degree doctor scientiarum}, address = {Trondheim, Norway}, month = {May}, url = {http://urn.ub.uu.se/resolve?urn=urn:nbn:no:ntnu:diva-2122}, issn = {1503-8181}, isbn = {978-82-471-8401-1}, number = {2008:119}, series = {Doctoral theses at NTNU} }

[KPCB08]

Anders Kofod-Petersen, Jörg Cassens, Patrick Brézillon, guest editors. Special issue: Modelling and Reasoning on Context. Revue d'Intelligence Artificielle, 22(5), 2008.

[WCBar]

Rebekah Wegener, Jörg Cassens, and David Butt. Start making sense: Systemic functional linguistics and ambient intelligence. Revue d'Intelligence Artificielle, 22(5):629-645, 2008.
[ doi ]

An operational model of context is particularly important for the successful integration of new technical artefacts into complex processes. One of the challenges for ambient intelligence is to embed technical artefacts into human work processes in such a way that they support the sense making processes of human actors instead of placing new burdens upon them. This paper examines some of the strengths and current limitations of a systemic functional model of context. We propose that the dimensions that are relevant to modeling are those that have the most consequences for meaning. This is explored in a hypothetical hospital scenario.

@Article{Wegener-Cassens-Butt-RIA-08, author = {Rebekah Wegener and J{\"o}rg Cassens and David Butt}, title = {Start Making Sense: Systemic Functional Linguistics and Ambient Intelligence}, journal = {Revue d'Intelligence Artificielle}, issn = {0992-499X}, pages = {629--645}, year = {2008}, volume = {22}, number = {5}, url = {http://dx.doi.org/10.3166/ria.22.629-645}, doi = {10.3166/ria.22.629-645} }

[PCKPD08]

Sobah Abbas Petersen, Jörg Cassens, Anders Kofod-Petersen, and Monica Divitini. To be or not to be aware: Reducing interruptions in pervasive awareness systems. In Jaime Lloret Mauri, Narcís Cardona, Kwang-Cheng Chen, Manuela Popescu, and Arta Doci, editors, Proceedings of the Second International Conference on Mobile Ubiquitous Computing, Systems, Services and Technologies - UBICOMM 2008, pages 327-332, Valencia, Spain, September/October 2008. IEEE Computer Society Press.
[ doi ]

In this paper we look at awareness systems that use mobile and ambient devices for collecting or presenting awareness information and operate within an Ambient Intelligence Environment. Our focus is on Pervasive Awareness Systems (PAS) that mediate awareness with the aim to improve the feeling of being connected. In particular, we concentrate on the challenges that are connected to participation in multiple communities, requiring a continuous balancing between the need to ``keep in touch'' and to reduce interruptions. In the paper, we discuss software agents as a possible solution and identify the different roles that agents can play in reducing interruptions.

@InProceedings{Petersen-et_al-UBICOMM-08, author = {Sobah Abbas Petersen and J\"{o}rg Cassens and Anders Kofod-Petersen and Monica Divitini}, title = {To be or not to be Aware: Reducing Interruptions in Pervasive Awareness Systems}, editors = {Jaime Lloret Mauri and Narcís Cardona and Kwang-Cheng Chen and Manuela Popescu and Arta Doci}, booktitle = {Proceedings of the Second International Conference on Mobile Ubiquitous Computing, Systems, Services and Technologies -- {UBICOMM 2008}}, pages = {327--332}, address = {Valencia, Spain}, year = 2008, month = {September/October}, publisher = {IEEE Computer Society Press}, url = {http://dx.doi.org/10.1109/UBICOMM.2008.35}, isbn = {978-0-7695-3367-4} }

[CKP07b]

Jörg Cassens, Anders Kofod-Petersen, Sobah Abbas Petersen, and Monica Divitini. Explanations and privacy in intelligent social awareness applications. In Thomas R. Roth-Berghofer, Stefan Schulz, Daniel Bahls, and David B. Leake, editors, Proceedings of the 3^rd International Workshop on Explanation-aware Computing - ExaCt 2008, pages 108-117, Patras, Greece, July 2008.
[ pdf ]

Explanations play an important part in the interaction with any intelligent system. This is particular important in context-aware and social awareness systems that regularly assume responsibility for a user and act proactively. Explanations are often generated using all available information. However, privacy issues in context-aware systems might dictate a limited distribution of information. The work presented here demonstrates how personal awareness-systems can fulfil different goals a user can have towards explanations, yet maintain a sensible level of privacy.

@InProceedings{Cassens-et_al-EXACT-08, author = {J\"{o}rg Cassens and Anders Kofod-Petersen and Sobah Abbas Petersen and Monica Divitini}, title = {Explanations and Privacy in Intelligent Social Awareness Applications}, editor = {Thomas R. Roth-Berghofer and Stefan Schulz and Daniel Bahls and David B. Leake}, booktitle = {Proceedings of the 3$^{\textrm{\scriptsize rd}}$ International Workshop on Explanation-aware Computing -- ExaCt 2008}, url = {http://ceur-ws.org/Vol-391/00010108.pdf}, year = 2008, address = {Patras, Greece}, month = {July}, pages = {108--117} }

[CWar]

Jörg Cassens and Rebekah Wegener. Making use of abstract concepts - systemic-functional linguistics and ambient intelligence. In Max Bramer, editor, Artificial Intelligence in Theory and Practice II -- IFIP 20^th World Computer Congress, IFIP AI Stream, volume 276 of IFIP, pages 205-214, Milano, Italy, 2008. Springer.
[ doi ]

An operational model of context is particularly important for the successful integration of new technical artefacts into complex processes. One of the challenges for ambient intelligence is to embed technical artefacts into human work processes in such a way that they support the sense making processes of human actors instead of placing new burdens upon them. This paper examines some of the strengths and current limitations in a systemic functional model of context. We propose that the dimensions that are relevant to modelling are those that have the most consequence for meaning, particularly how the participants involved in a social process construe that social process.

@InProceedings{Cassens-Wegener-IFIP-AI-08, author = {J{\"o}rg Cassens and Rebekah Wegener}, title = {Making Use of Abstract Concepts -- Systemic-Functional Linguistics and Ambient Intelligence}, editor = {Max Bramer}, booktitle = {Artificial Intelligence in Theory and Practice II -- IFIP 20$^{\textrm{\scriptsize th}}$ World Computer Congress, IFIP AI Stream}, pages = {205--214}, year = {2008}, volume = {276}, series = {IFIP}, address = {Milano, Italy}, publisher = {Springer}, doi = {10.1007/978-0-387-09695-7_20}, url = {http://dx.doi.org/10.1007/978-0-387-09695-7_20}, issn = {1571-5736}, }

[KPCLZ08]

Anders Kofod-Petersen, Jörg Cassens, David B. Leake, and Marielba Zacarias, editors. HCP-2008 Proceedings, Part II, MRC 2008 - Fifth International Workshop on Modelling and Reasoning in Context. ISBN 978-2-908849-22-6. TELECOM Bretagne, June 2008.
[ info/pdf ]

@Proceedings{Kofod-Petersen-Cassens-Leake-Zacarias-MRC-08, title = {HCP-2008 Proceedings, Part II, MRC 2008 -- Fifth International Workshop on Modelling and Reasoning in Context}, year = 2008, editor = {Anders Kofod-Petersen and J\"{o}rg Cassens and David Leake and Marielba Zacarias}, month = {June}, isbn = {978-2-908849-22-6}, publisher = {TELECOM Bretagne}, url = {http://wiki.decis.nl/publichcp2008/content/view/82/73/} }

[KPCar]

Anders Kofod-Petersen, Jörg Cassens, and Agnar Aamodt. Explanatory capabilities in the CREEK knowledge-intensive case-based reasoner. In Anders Holst, Per Kreuger, and Peter Funk, editors, Tenth Scandinavian Conference on Artificial Intelligence (SCAI 2008), pages 28-35, Stockholm, Sweden, 2008. IOS Press.
[ info/pdf ]

The ability to give explanations for its reasoning and behaviour is a core capability of an intelligent system. There are a number of different goals a user can have towards such explanations. This paper presents how the knowledge intensive case-based reasoning framework CREEK can support some of these different goals in an ambient intelligence setting.

@InProceedings{Kofod-Petersen-Cassens-Aamodt-SCAI-08, author = {Anders Kofod-Petersen and J\"org Cassens and Agnar Aamodt}, title = {Explanatory Capabilities in the {CREEK} Knowledge-Intensive Case-Based Reasoner}, editor = {Anders Holst and Per Kreuger and Peter Funk}, booktitle = {Tenth Scandinavian Conference on Artificial Intelligence (SCAI 2008)}, pages = {28--35}, year = {2008}, volume = 173, isbn = {978-1-58603-867-0}, series = {Frontiers in Artificial Intelligence and Applications}, address = {Stockholm, Sweden}, month = {May}, publisher = {IOS Press} }

2007

[KPCLS07]

Anders Kofod-Petersen, Jörg Cassens, David B. Leake, and Stefan Schulz, editors. Proceedings of the 4th International Workshop on Modeling and Reasoning in Context (MRC 2007), number 112 in Computer Science Research Report, Roskilde, Denmark, 2007. ISSN 0109-9779. Roskilde University Center.
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This research report constitutes the proceedings of the 4th International Workshop on Modeling and Reasoning in Context (MRC 2007) with Special Session on the Role of Contextualization in Human Tasks (CHUT) which is held in conjunction with the 6th International and Interdisciplinary Conference on Modeling and Using Context (CONTEXT 2007), Roskilde University, Denmark, August 2007.

[KPC07]

Anders Kofod-Petersen and Jörg Cassens. Explanations and context in ambient intelligent systems. In Boicho Kokinov, Daniel C. Richardson, Thomas R. Roth-Berghofer, and Laure Vieu, editors, Modeling and Using Context - CONTEXT 2007, volume 4635 of LNCS, pages 303-316, Roskilde, Denmark, 2007. Springer.
[ bib | doi ]

Ambient intelligent systems are context aware by perceiving and reasoning about their environment, they perceive the needs of their users and proactively respond to these needs by being context sensitive. Users do not interact with these systems by traditional means only, but also through behavioural interfaces. This combination of mixed initiative systems and unconventional interfaces puts strong requirements on the explanatory capabilities of any system. The work presented here focuses on explaining the behaviour of an ambient intelligent systems to its users. It demonstrates how explanations can be combined with context to deal with the different types of explanations that are required for a meaningful interaction of a system and its users.

[CKP07b]

Jörg Cassens and Anders Kofod-Petersen. Explanations and case-based reasoning in ambient intelligent systems. In David C. Wilson and Deepak Khemani, editors, ICCBR-07 Workshop Proceedings, pages 167-176, Belfast, Northern Ireland, 2007.
[ bib | pdf | pdf ]

Interacting with intelligent systems in general and ambient intelligent systems in particular, requires that these systems have the ability to build a trust relationship with the users. The ability to explain its own behaviour is one of the most important abilities that such a system can exhibit to gain trust. We argue that explanations are not just an addition to an ambient intelligent system rather it is an approach to the design and implementation of such a system. Explanations are useful both for the reasoning process itself and as a means of communicating with the users. In this paper, we present a knowledge intensive approach for identifying different contexts and generating a course of action depending on the context found. We explore the use of explanations both as a means of reasoning and as a means of communication with the user.

[CKP07a]

Jörg Cassens and Anders Kofod-Petersen. Designing explanation aware systems: The quest for explanation patterns. In Thomas R. Roth-Berghofer, Stefan Schulz, and David B. Leake, editors, Explanation-Aware Computing - Papers from the 2007 AAAI Workshop, number WS-07-06 in Technical Report, pages 20-27, Vancouver, BC, 2007. AAAI Press.
[ bib | info | pdf ]

Systems in general, and intelligent systems in particular, need to be able to explain their behaviour to their users or partners. Previously, a number of different user goals that explanations can support have been identified. Likewise, different kinds of explanations have been proposed. The problem remains how these abstract concepts can be made fruitful for the design of intelligent systems - they must be connected to software engineering methodologies. The work presented here builds on the concept of patterns and suggests using problem frames as a tool for requirements engineering. We further on propose to connect these problem frames with other design patterns as a tool supporting the implementation process.

2006

[CKP06]

Jörg Cassens and Anders Kofod-Petersen. Using Activity Theory to Model Context Awareness: a Qualitative Case Study. In Geoff C. J. Sutcliffe and Randy G. Goebel, editors, Proceedings of the Nineteenth International Florida Artificial Intelligence Research Society Conference, pages 619-624, Melbourne Beach, 2006. AAAI Press.
[ bib | info ]

In this paper, we describe an approach to modelling context-aware systems starting on the knowledge level. We make use of ideas from Activity Theory to structure the general context model and to assess empirical data. We further on describe how the data-driven and the model-driven aspects of our approach are combined into a single knowledge model. We outline the design of an empirical study conducted to gather information about a concrete workplace environment. This information is then used to populate our context model. We describe also how the collected data can be used to validate our approach.

[KPC06]

Anders Kofod-Petersen and Jörg Cassens. Using Activity Theory to Model Context Awareness. In Thomas R. Roth-Berghofer, Stefan Schulz, and David B. Leake, editors, Modeling and Retrieval of Context: MRC 2005, Revised Selected Papers, volume 3946 of LNCS, pages 1-17, Edinburgh, 2006. Springer.
[ bib | doi ]

One of the cornerstones of any intelligent entity is the ability to understand how occurrences in the surrounding world influence its own behaviour. Different states, or situations, in its environment should be taken into account when reasoning or acting. When dealing with different situations, context is the key element used to infer possible actions and information needs. The activities of the perceiving agent and other entities are arguably one of the most important features of a situation; this is equally true whether the agent is artificial or not.
This work proposes the use of Activity Theory to first model context and further on populate the model for assessing situations in a pervasive computing environment. Through the socio-technical perspective given by Activity Theory, the knowledge intensive context model, utilised in our ambient intelligent system, is designed.

2005

[SCA05]

Frode Sørmo, Jörg Cassens, and Agnar Aamodt. Explanation in Case-Based Reasoning - Perspectives and Goals. Artificial Intelligence Review, 24(2):109-143, October 2005.
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We present an overview of different theories of explanation from the philosophy and cognitive science communities. Based on these theories, as well as models of explanation from the knowledge-based systems area, we present a framework for explanation in case-based reasoning (CBR) based on explanation goals. We propose ways that the goals of the user and system designer should be taken into account when deciding what is a good explanation for a given CBR system. Some general types of goals relevant to many CBR systems are identified, and used to survey existing methods of explanation in CBR. Finally, we identify some future challenges.

[Cas05]

Jörg Cassens. User Aspects of Explanation Aware CBR Systems. In Maria Francesca Costabile and Fabio Paternó, editors, Human-Computer Interaction - INTERACT 2005, volume 3585 of LNCS, pages 1087-1090, Rome, 2005. Springer.
[ bib | doi | pdf ]

This paper addresses the problem of embedding explanation-aware intelligent systems into a workplace environment. We outline an approach with three different perspectives, focusing on the work process as a whole as well as user interaction from an interface and a system view. The theoretical background consists of Actor Network Theory, Semiotics, and Activity Theory. We further propose to integrate this workplace analysis into a design process for knowledge-intensive and explanationaware Case-Based Reasoning systems.

[RBC05]

Thomas R. Roth-Berghofer and Jörg Cassens. Mapping Goals and Kinds of Explanations to the Knowledge Containers of Case-Based Reasoning Systems. In Héctor Muñoz-Avila and Francesco Ricci, editors, Case Based Reasoning Research and Development - ICCBR 2005, volume 3630 of LNAI, pages 451-464, Chicago, 2005. Springer.
[ bib | doi | pdf ]

Research on explanation in Case-Based Reasoning (CBR) is a topic that gains momentum. In this context, fundamental issues on what are and to which end do we use explanations have to be reconsidered. This article presents a prelimenary outline of the combination of two recently proposed classifications of explanations based on the type of the explanation itself and user goals which should be fulfilled. Further on, the contribution of the different knowledge containers for modeling the necessary knowledge is examined.

[KPC05]

Anders Kofod-Petersen and Jörg Cassens. Activity Theory and Context-Awareness. In Stefan Schulz, David B. Leake, and Thomas R. Roth-Berghofer, editors, IJCAI-05 Workshop on Modelling and Retrieval of Context - Working Notes, pages 1-12, Edinburgh, 2005. IJCAI.
[ bib | pdf | pdf ]

A lot of research has been done in the area of context-aware computing. Even though, the term context seems often not to be well defined. We attribute this problem partly to the fact that research often focuses on syntactical and technical issues of contextuality and does not take a knowledge level perspective on context. When including the knowledge level, some sort of analysis is required on what aspects need to be modelled. In this paper, we propose the use of an Activity Theory (AT) based approach on modelling components, and outline how it can be combined with the AmbieSense context modelling framework we have proposed earlier.

[RBCS05]

Thomas R. Roth-Berghofer, Jörg Cassens, and Frode Sørmo. Goals and Kinds of Explanations in Case-Based Reasoning. In Klaus Dieter Althoff, Andreas Dengel, Ralph Bergmann, Markus Nick, and Thomas Roth-Berghofer, editors, WM 2005: Professional Knowledge Management - Experiences and Visions, pages 264-268, Kaiserslautern, 2005. DFKI.
[ bib | pdf ]

Research on explanation in Case-Based Reasoning (CBR) is a topic that gains momentum. In this context, fundamental issues on what are and to which end do we use explanations have to be reconsidered. This article presents a prelimenary outline of the combination of two recently proposed classifications of explanations based on the type of the explanation itself and user goals which should be fulfilled.

2004

[Cas04]

Jörg Cassens. Knowing What to Explain and When. In Pablo Gervás and Kalyan May Gupta, editors, Proceedings of the ECCBR 2004 Workshops, number 142-04 in Technical Report of the Departamento de Sistemas Informáticos y Programación, Universidad Complutense de Madrid, pages 97-104, Madrid, 2004.
[ bib | pdf | pdf ]

We have argued elsewhere that user goals should be taken into account when deciding what kind of explanation of its results a CBR system should give. In this paper, we propose the use of an Activity Theory based methodology for identifying different user goals and expectations towards explanations given by a system supporting a work process.

[SC04]

Frode Sørmo and Jörg Cassens. Explanation Goals in Case-Based Reasoning. In Pablo Gervás and Kalyan May Gupta, editors, Proceedings of the ECCBR 2004 Workshops, number 142-04 in Technical Report of the Departamento de Sistemas Informáticos y Programación, Universidad Complutense de Madrid, pages 165-174, Madrid, 2004.
[ bib | pdf | pdf ]

In this paper, we present a short overview of different theories of explanation. We argue that the goals of the user should be taken into account when deciding what is a good explanation for a given CBR system. Some general types relevant to many Case-Based Reasoning (CBR) systems are identified and we use these goals to identify some limitations in using the case as an explanation in CBR systems.

2003

[Cas03]

Jörg Cassens. A Work Context Perspective on Mixed-Initiative Intelligent Systems. In Proceedings of the IJCAI 2003 Workshop on Mixed-Initiative Intelligent Systems, pages 30-35, Acapulco, 2003.
[ bib | pdf | pdf ]

The issue of mixed-initiative intelligent systems has gained increasing interest in recent years. In particular, much attention has been paid on sharing the initiative between the user and the system on the tool level. In this paper, we are focusing on the problem of embedding the system into a workplace. We are proposing a framework for the analysis of how intelligent systems fit into a work context. We outline an approach with three different perspectives, focusing on the work process as a whole as well as human computer interaction on the interface and system level. The theoretical background consists of the Actor Network Theory, Semiotics, and the Activity Theory. We describe some challenges for the design of mixed initiative intelligent systems and outline how our framework might help to deal with these challenges.

[CFC03]

Zoran Constantinescu-Fulöp and Jörg Cassens. It's Magic: SourceMage GNU/Linux as HPC Cluster OS. In LinuxTag 2003, Karlsruhe, 2003. LinuxTag.
[ bib | pdf ]

The goal of the presentation is to give an overview about how to build a commodity PC based GNU/Linux cluster for High Performance Computing (HPC) in a research environment. Due to the extreme flexibility of the GNU/Linux operating system and the large variety of hardware components, building a cluster for High Performance Computing (HPC) is still a challenge in many cases. At the Division of Intelligent Systems at the Norwegian University of Science and Technology (NTNU), we have build a 40 node HPC cluster for research purposes using the source-based GNU/Linux distribution Source Mage. We describe a methodology for designing and installing a highly customized GNU/Linux cluster. Different types of Linux distributions will be mentioned, binary-based and source-based, with their advantages and disadvantages. The presentation will focus on using SourceMage for HPC, specifying the magical ideas behind it: the ease of upgrading to the latest available version of the source code, a packaging system for keeping track of dependencies, optimized compiles for the hardware architecture used, easy integration of new packages, amongst others.

2002

[Cas02]

Jörg Cassens. User Aspects of Situated CBR Systems.
In Proceedings of the ECCBR 2004 Workshops, Aberdeen, 2002. Robert Gordon University.
[ bib ]

2001

[Cas01]

Jörg Cassens. Zum Verhältnis der Informatik zu anderen Fachdisziplinen. In Frieder Nake, Arno Rolf, and Dirk Siefkes, editors, Informatik - Aufregung zu einer Disziplin, number 235 in Berichte, pages 36 - 38, Heppenheim, 2001. Universität Hamburg, Fachbereich Informatik.
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1999

[CW99]

Jörg Cassens and Jens Woinowski. Kritische Informatik - Versuch einer Begriffsbildung. In Peter Bittner and Jens Woinowski, editors, Mensch - Informatisierung - Gesellschaft, number 1 in Serie Kritische Informatik, pages 115 - 139, Münster, 1999. FIfF Jahrestagung 1998, Lit-Verlag.
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1998

[Cas98b]

Jörg Cassens. Zwischen Vision und Machbarkeit. In Tagungsband JOINT-96, number 3 in Schriftenreihe Kritische Wissenschaft, pages 2 - 8, Oldenburg, 1998. AK Kritische Informatik.
[ bib ]

[Cas98a]

Jörg Cassens. Unscharfe Methoden zur Analyse individuenorientierter Simulationsmodelle in der Epidemiologie. Diplomarbeit, Fachbereich Informatik der Carl von Ossietzky Universität, Oldenburg, 1998.
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Diese Diplomarbeit soll einen Beitrag zu Untersuchungen zum Einsatz individuenorientierter Simulationsmodelle und deren Analyse zur Unterstützung der umweltepidemiologischen Forschung liefern. Ziel ist es, das Design empirischer Studien zu optimieren, die Identifizierung von Ursache-Wirkungs-Zusammenhängen zu erleichtern sowie die Entwicklung neuer und den Test bekannter Hypothesen zu unterstützen. In der vorliegenden Arbeit wird die Analyse individuenorientierter Simulationsmodelle mittels unscharfer und KI-basierter Methoden des Maschinellen Lernens untersucht.

1995

[Cas95a]

Jörg Cassens. Zum Subjekt der Veränderung. In Tagungsband JOINT-95, number 1 in Schriftenreihe Kritische Wissenschaft, pages 26 - 31, Oldenburg, 1995. AK Kritische Informatik.
[ bib ]

[Cas95b]

Jörg Cassens. Zwischen Vision und Machbarkeit. FIFF Kommunikation, (3):7, 1995. ISSN 0938-3476.
[ bib ]