With the expansion of electronic exchanges and the nearly universal access to the Internet, it has become possible for retail investors to buy and sell exchange-traded derivative contracts from their desktops. In Europe this ability has even been extended to allow small investors to purchase over-the-counter exotic option contracts through the Internet. In this article, Muck analyzes the pricing of a variety of web-traded exotic instruments, available in this „market.” As one would expect, the contracts are overpriced on average, relative to theoretical valuations based on exchange-traded options on the same underlying DAX index. A second hypothesis, that overpricing diminishes as the contracts approach maturity receives a little less support.
The WS-Agreement Standard as defined in the current proposal does not accommodate negotiation between service provider and requesters to yield an agreement. It is limited to simple offers and acceptances. However, negotiations between service providers and service consumers beyond the basic mechanism are required and are also part of the charter of the GRAAP working group. There are many mechanisms for negotiating agreements between parties for different purposes, having different sets of participants, different economic properties, different interactions patterns, and different information requirements to enter the interaction. Given the generality of the WS-Agreement scope, supporting a single negotiation mechanism would not satisfy the requirements of different application scenarios. Hence, the objective of this thesis is to devise a proposal to extend the WS-Agreement specification to facilitate the integration of arbitrary negotiation protocols into the WS-Agreement interaction. This includes facilities to enable a party to advertise the negotiation protocol it supports, the role that it can take in this protocol, expectations on other roles in the negotiation, and other meta-information that is necessary to start an interaction. This thesis analyzes the scope of negotiation protocols relevant for service level agreement establishment, derives a data structure for negotiation protocol meta-data, a protocol to exchange meta-data and initiate a negotiation protocol, and obtaining the result of the negotiation, the agreement. The new functionality extends the current WS-Agreement specification seamlessly. The thesis demonstrates the viability of the approach using scenarios of specific negotiation mechanisms.
Multi-Agent Systems (MAS) promise a new advance in distributed computing. In MAS autonomous software agents flexibly cooperate, coordinate, and compete to provide the desired function(s) of such a system. If some components of a MAS fail or do not provide the desired functionality, the system is expected to autonomously deal with these situations. It is desirable to reduce occurrences of such situations by selecting trustworthy cooperation partners before cooperating with them. This becomes even more desirable and important in an open MAS where arbitrary heterogeneous software agents, deployed by different parties, participate in the MAS, as it becomes more likely that these agents fail or try to exploit the MAS for their own purposes without reciprocation. In order to monitor agent behavior and enable selection of trustworthy cooperation partners, trust or reputation management services can be applied. As there is no central control in an open MAS and it is completely distributed these services themselves have to be distributed. This paper proposes a fully distributed reputation management service for open MAS based on peer-to-peer technology (especially distributed hash tables). A Java-based implementation of that service, which is intended as a plug-in for multi-agent platforms, is also described.
The Simulation of Action Strategies of Different Personalities in Perspective of the Interaction between Emotions, Motivations, and Cognition (An Experimental Study in the Field of Cognitive Psychology and Artificial Intelligence) Inaugural-Dissertation in der Fakultät Pädagogik, Philosophie und Psychologie der Otto-Friedrich-Universität Bamberg submitted by Ayman Elkady Abstract 1. Introduction: This research investigates the relationship between the theoretical basis of PSI-theory by Dietrich Dörner and the actual performance of subjects in the Island-game (a well-structured problem in an uncertain environment). The study compares the behavior of human subjects and the PSI simulation. The main results show that the PSI agent is not only able to simulate the different strategies of the experimental subjects, but also able to simulate single cases of personality. 2. Participants: A sample of 40 subjects participated in the experiment. The sample of participants was divided into two groups (group A and group B). Each group consisted of twenty participants. While "group A" played an island-game whos resources could be renewed, group B played the non-renewable resources version. 3. Materials: Island game, a computer simulation of a robot, called James, - endowed with several needs (e.g. for energy, for water), was used. The "island" contains numerous locations with different objects that can be manipulated in various ways. Manipulations of the objects can have effects on the robot (e.g. water can be drunk and the need for food is satisfied). Subjects have to control the robot and satisfy his existential needs. Moreover, they have to collect energy-rich-lumps of rock called 'Nucleotides'. 4. Experimental Design and Procedure: At the beginning of the experiment, participants were informed that they took part in a problem-solving experiment. Before beginning the first session, standard instructions for the task were given using Power Point presentation that explained the basic rules of the game and the tasks, namely, to keep the robot alive (e.g. to find enough water and food for the robot) and to collect so-called "Nucleotides". During these periods and all experimental conditions, subjects were allowed to think and speak freely. 5. Results of the experiment: The experiment show that there are no differences between the results of the participants of group A and the results of the participants of group B with respect to the eight dependent variables and the fact that the participants had played the game using different strategies. Therefore, we can assume that in this case the type of environment, whether poor or rich, does not play an important role. Most important is the way (the strategy) the available resources are managed by the actors. We have found these playing strategies: The Nucleotides-First-Strategy: Nucleotides are considered as a main motive and the existential needs of the robot are ignored. Survival-strategy: Existential needs of the robot are considered as a main motive and nucleotides are ignored. The Balance-Between-Motives-Strategy: Some participants made a balance between motives. In other words, some participants were capable of achieving both tasks (saving the robot from breakdowns and collecting nucleotides) by considering all goals of existential needs together with nucleotides. Stereotype-strategy: All goals of the different motives are included and are accompanied by a low selection threshold. 6. Simulation: We proposed that the PSI-program (and of course the theory behind the program) had motives, emotions and cognitive processes similar to those which human participants had in the experiment. Therefore, we set PSI-parameters in way that could simulate and produce the same strategies the subjects used in the experiment. The program was run with varying chance values within the specific range of all parameters. Simulation time had been varied because we discovered that the subjects had different playing-speeds. 7. Results of the simulation: The PSI model can produce the same strategies that the subjects had used during playing the Island game. There are highly significant correlations between PSI's behavioral parameters and the subjects' means for all parameter sets. Moreover, qualitative analyses of the two single cases indicated that PSI can also simulate single case strategies.
Information about online presence allows participants of instant messaging (IM) systems to determine whether their prospective communication partners will be able to answer their requests in a timely manner, or not. That is why presence information, combined with the ability to send instant messages, makes IM more personal and closer than other forms of communication such as e-mail. On the other hand, revelation of presence constitutes a potential of misuse by untrustworthy entities. A possible risk is the generation of online logs disclosing user habits. This makes presence information a resource worth protecting. We argue, however, that current IM systems do not take reasonable precautions to protect presence information. We implemented an IM system designed to be robust against attacks to disclose a user’s presence. In contrast to existing systems, it stores presence information in a registry in a way that is only detectable and applicable for intended users and not comprehensible even for the registry itself. We use a distributed hash table (DHT) as registry and apply an anonymous communication network to protect the physical addresses of both senders and receivers of messages.
The way business processes are organised heavily influences the flexibility and the expenses of enterprises. The capability to address changing market needs in a timely manner and to provide appropriate pricing is indispensable in a world of internationalisation and growing competition. Optimising processes that cross enterprise boundaries potentially is a key success factor in achieving this goal but it requires the information systems of the participating enterprises to be consistently integrated. This gives rise to some challenging tasks. The personnel involved in building up business collaborations comes from different enterprises with different business vocabulary and background which requires extensive communication support. The lack of central technical infrastructure, typically prohibited by business politics, often calls for a distributed and computer-aided collaboration structure, so that the resulting complexity must be handled somehow. Nevertheless robustness is an important factor in building business collaborations as these may exchange goods of considerable value. This technical report proposes the use of a two step modelling approach that separates business logic, modelled in the so-called centralised perspective (CP), from its distributed implementation, modelled in the so-called distributed perspective (DP). The separation of these perspectives enables business people to concentrate on business issues and to solve communication problems in the CP whereas technical staff can concentrate on distribution issues. The use of stringent modelling rules is advised in order to provide the basis for formal analysis techniques as one means to achieve robustness. Considering the choreography of RosettaNet Partner Interface Processes (PIPs) as the subject of my analysis, UML activity diagrams for modelling the CP and WSBPEL for modelling the DP are described as enabling techniques for implementing the proposed two step modelling approach. Further, model checking is applied to validate the CP and DP models in order to detect errors in early design phases. As the adequacy of model checking tools highly depends on the detailed modelling techniques as well as the properties to be checked, a major part of our discussion covers relevant properties and requirements for a model checker.