OC-Trust

DFG-Research Unit, start: October 2009

Cooperation:

Prof. Dr. Müller-Schloer, Prof. Dr. Hähner (Systems Engineering, Hannover), 

Prof. Dr. André (Multimedia Concepts and Applications, Augsburg), 

Prof. Dr. Reif (Software Engineering, Augsburg), 

Prof. Dr. Ungerer (Systems and Networking, Augsburg)

Systems designed according to the Organic Computing paradigm, can quickly adapt their behaviour and even their architecture to changing situations. This reorganisation can be triggered by environmental conditions or other constraints that have influence on these systems. The adaption of such a system can improve the system, as it can become more applicable for the environment it is used in or more robust to certain failures. However, as the adaption can change the system fundamentally, a new approach is needed to cover for the possible loss of trustworthiness of the system. In the project OC-Trust, we at SRA focus on system-to-system Trust. We are especially interested in Trust relations between entites of the system, expressed as credibility of these entities.

The following is a short summary of the work we conducted in cooperation with our project partners:

Throughout the project we address basic technologies, integration, application and extension of Trust mechanisms in each of the following fields:

• Agent level
• System level
• Institutional control
• Demonstration and evaluation
  

Agent level: 

Here, our focus is on the design of trust-adaptive agents. In this context, we have defined and implemented an agent architecture that allows agents to make strategic short- and long-term decisions based on the notion of Trust. This is backed up by the utilisation of the Observer/Controller-paradigm known from several Organic Computing projects. Here, the Observer is responsible for generating a meaningful and correct situation description for the agent. As we are mainly interested in Trust, this description integrates dimensions as agent reputation and personal experiences with other agents. The Controller is responsible for the generation of adequate behavioural strategies for the observed situations. This incorporates such diverse behaviours as selfish improvement of the agent's fitness or altruistic efforts to improve the overall system (with possible negative side-effects on the fitness of the agent).

In related future work, amongst others, we plan to address the development of a fine-grained situation description and the application of machine learning techniques to dynamically map situations descriptions to effective strategies.

System level:

On the system level we examine the decentralised formation of Trust-based agent organisations that increase the member's effectiveness. These so-called Trusted Communities (TC) come in two flavours: The implicite TC is built between agents with mutual Trust relations without the explicite knowledge of the agents. Membership is therefore defined by the system designer and the TC concept is used mainly analytically. On the other hand, the explicite TC is formed based on membership contraints and managed explicitely by an according agent. Members here, are known to other members and can be treated different than non-members, allowing for elaborate strategic options and further effectiveness improvement.

In related future work, amongst others, we plan to investigate and implement the concept of explicite Trusted Communities and examine their lifecycle management and evaluate their potential for fitness improvement. 

Institutional control:

Institutional control can guide agents through norms and sanctioning mechanisms to avoid the emergence of negative behaviour. In the regarded systems selfish strategies and other local behaviour can lead to ineffective global performance of the system. Institutions can observe local behaviour and impose norms whenever the system is likely to take damage from this behaviour. In future work we want to examine how institutional control via deontic norms can improve the system while maintaing a high degree of subsystem autonomy. 

Demonstration and evaluation:

In order to evaluate the applicability of the developed techniques and mechanisms to Organic Systems, we apply them to a demonstration scenario. This demonstrator is set in the area of Desktop Grid Computing. Here, we built a system that incoporates trust-adaptive agents as control entities of a Desktop Grid Client software. The agents act on behalf of a user and apply the described mechanisms to efficiently process jobs created by user applications. 

Currently, we work with a simulation of this system - it is planned to shift to an actual Desktop Grid System based on a middleware developed by our project partners.

Available student theses

Theses can be written in German or English. If you are interested in a topic or have own ideas about a thesis, please do not hesitate to contact us.

Student theses in progress

Supervised student theses

1. [Blu10] Bluhm, D.: "Analysis and implementation of social cooperation strategies based on an evolutionary trust model". Bachelor Thesis, 2010.
2. [Tav10] Tavakkoli, H.: "Bachelor Thesis: Untersuchung von Metriken zum Vergleich spieltheoretischer Ansätze in Multiagentensystemen". Bachelor Thesis, 2010.
3. [Bae10] Bähre, P.: "Entwurf und Implementierung einer Desktop Grid Applikation zur Gesichtserkennung". Master Thesis, 2010.
4. [Bec10] Becher, R.: "Analysis of the applicability of Game-theoretic approaches to trust-based self-organising systems". Bachelor Thesis, 2010.
5. [Bro11] Brockmann, Falk: "Analyse und Vergleich von Trust- und Reputationsmetriken für ein Desktop Grid System". Master Thesis, 2011.
6. [Thi11] Thimm, Markus: "Spieltheoretische Analyse des Einflusses vergangener Entscheidungen auf die Strategiewahl". Bachelor Thesis, 2011.
7. [Bus11]Busch, S.: "Untersuchung des Systemverhaltens eines vertrauensbasierten Desktop Grid Systems", Bachelor thesis,2011
8. [S-P11]Saint-Paul, F.: "Erweiterung und Evaluation einer Desktop Grid Simulation für vertrauenswürdige Agenten - Volatilität und Lokalität", Master thesis, 2011
9. [Jas11]Jaschke, S.: "Implementierung und Evaluation von auktionsbasierten Agenten für ein Desktop Grid System", Master thesis, 2011
   

Related Workshops

Trustworthy Self-Organizing Systems (TSOS): Workshop at the Fourth IEEE International Conference on Self-Adaptive and Self-Organizing Systems 2010
TSOS 2010, Budapest, September 27 – October 1, 2010

Trustworthy Self-Organizing Systems (TSOS): Workshop at the Fifth IEEE International Conference on Self-Adaptive and Self-Organizing Systems 2011
TSOS 2011, Ann Arbor, October 3, 2011

Link: http://swt.informatik.uni-augsburg.de/tsos/

Publications (with SRA participation)

[And11TR] Gerrit Anders, Lukas Klejnowski, Jan-Philipp Steghöfer, Florian Siefert, Wolfgang Reif, "Reference Architectures for Trustworthy Energy Management and Desktop Grid Computing Applications", Technical Report 2011-11, Universitätsbibliothek der Universität Augsburg, Universitätsstr. 22, 86159 Augsburg, 2011

[Kle10TSOS] Lukas Klejnowski, Yvonne Bernard, Jörg Hähner and Christian Müller-Schloer, "An architecture for trust-adaptive agents", Proceedings of the 2010 Fourth IEEE International Conference on Self-Adaptive and Self-Organizing Systems Workshop (SASOW 2010) 

[Ste10TSOS] Jan-Philipp Steghöfer, Florian Nafz, Wolfgang Reif, Yvonne Bernard, Lukas Klejnowski, Jörg Hähner and Christian Müller-Schloer, "Formal Analysis of Trusted Communities", Proceedings of the 2010 Fourth IEEE International Conference on Self-Adaptive and Self-Organizing Systems Workshop (SASOW 2010) 

[Ste10ATC] Jan-Philipp Steghöfer, Rolf Kiefhaber, Karin Leichtenstern, Yvonne Bernard, Lukas Klejnowski, Wolfgang Reif, Theo Ungerer, Elisabeth André, Jörg Hähner, and Christian Müller-Schloer, "Trustworthy Organic Computing Systems: Challenges and Perspectives", Proceedings of the 7th International Conference on Autonomic and Trusted Computing (ATC 2010), Springer 

[Ber10PCGrid] Yvonne Bernard, Lukas Klejnowski, Jörg Hähner, Christian Müller-Schloer, "Towards Trust in Desktop Grid Systems", ccgrid, pp.637-642, 2010 10th IEEE/ACM International Conference on Cluster, Cloud and Grid Computing, 2010

Further information and contact

Further info:

Visit the OC-Trust project homepage of our cooperation partners in Augsburg.

Contact:

M.Sc. Yvonne Bernard

M.Sc. Lukas Klejnowski