Otmar Görlitz

Automated negotiations of supply contracts for flexible production networks

Abstract Non-hierarchical regional production networks are the object of a collaborative research project carried out at Chemnitz University of Technology. Non-hierarchical production networks are created by forming a co-operation of small autonomous manufacturing units, so called competence cells. The cells autonomy in the network model allows each cell to pursue its own agenda of production tasks. Thus a cells agenda might be in conflict with supply requests within the network. The resolution of such conflicts requires a negotiation between client and supplier to harmonise their individual interests. Our paper proposes a software agent, capable to conduct an automated negotiation in this situation, in order to assist the human decision-maker and accelerate the harmonisation. The agent can perform an integrative negotiation about multiple interdependent properties of the supply contract, such as price, volume and delivery date. The negotiation protocol follows the offer–counteroffer principle and an adaptive offer generation strategy. However, based on the utility theory, the agent is able to create a bundle of equally good offers, each of them consisting of a particular combination of property values. By proposing more than one offer, the number of negotiation acts is reduced to a necessary minimum and the overall quality of a deal can improve. In the paper, we show the conflict resolution in the context of non-hierarchical production networks. Furthermore, we demonstrate that our agent model is flexible enough to be applied in supply scenarios requiring the negotiation of contracts.

Enabling integrative negotiations by adapitve software agents

One of the most important and complex aspects in Electronic Commerce is the automated negotiation between software agents. Most shopping assistance systems concentrate on price comparison agents or provide only the means to negotiating the price of articles. In our paper we present the model of an intelligent and adaptive software agent to support integrative negotiations of multiple interdependent properties of products. The agent is able to consider an arbitrary number of different properties whose values may be interdependent. Additionally, a ranking of the importance of the properties is maintained. Normalization of property values is an integral part of our model. The user does not need to transform desired values to abstract scales. Furthermore, normalization allows properties of different types to be the subject of one negotiation. Our agent can selectively act as a buyer or a seller of a product. The intelligent and adaptive behaviour throughout the negotiation is secured by a set of strategies, which determine the agents proposals and its reactions to its counterpart. The realization of these negotiation strategies is based on ideas adopted from the field of neural networks and vibrations theory.

Towards Content-Related Indexing in Databases

Modern business appliications require huge volumes of highdimensioinal data to be Stored. explorative queries, typically used in these applications, select groups of objects with similar attributes or attribute combinations. In contrast to multidimensional index structures designed for spatial data that assume dimension independence and very often a uniform distribution, we have developed a new database indexing concept that discovers correlation patterns and takes the nonuniform distribution into consideration. The corresponding analysis is done on the subsymbolic level by applying a hierarchical artificial neural network. The trained neural network organises the data into a hierarchy of clusters. The clusters can be interpreted as groups of similar objects on the symbolic level. The hierarchy is finally used to derive the Intelligent Cluster Index (ICIx). In this paper we present a description of the Intelligent Cluster Index, it’s creation and application as multidimensional index and as heuristic for a logical distribution schema. We describe first experimental results, showing that this new approach can significantly speed up the system performance.

Access to distributed environmental databases with ICIx technology

The Internet has become a favoured medium for the presentation and exchange of environmental and chemical data. To search for relevant information, the user either has to know the direct address of the Internet site, or has to use search engines and meta information repositories. In the latter case, the desired resource is described by a number of keywords, or descriptors. However, if too few descriptors are given, the answer set is immensely large. If too many or too specific descriptors are given, valuable information might be sorted out, because it lacks a particular descriptor. The Intelligent Cluster Index (ICIx) technology can remedy this situation. It generates a clustering of documents by their content characteristics. Applied in the described scenario this results in a grouping of Internet resources with comparable content. ICIx offers a similarity search facility based on the clustering. It allows the search for an arbitrary combination of descriptors. If an exact match is required, the result contains only documents matching all descriptors. In the similarity search, documents with comparable content – identified by the similarity clustering – can be included in the result set, even if they do not match all descriptors. Thus ICIx offers a wider range of relevant information in the answer than standard full text search provides.

Semantic Navigation Maps for Information Agents

In this paper we propose a new approach to represent entity semantics of loosely coupled systems by maintaining the topological neighborhood of context relations in a particular domain by a self organizing Kohonen map. We discuss how this technique can be applied to a distributed information system in order to find the most promising site to answer a particular query. Moreover, we show the applicability of our approach to any other system whose context can be described by certain semantical features. In general, our representation method can be seen as a kind of semantic distribution schema applicable for loosely coupled systems of various types — i.e., where systems can be information systems as well as databases or Internet-sites.

Die Suche nach Planungskompetenzen beim Aufbau von Produktionsnetzen

Kurzfassung Die Beschreibung von planerischen Kompetenzen stellt bisher ein weitgehend ungelöstes Problem dar. Es ist schwierig, diese Art von Fähigkeiten geeignet zu qualifizieren und zu quantifizieren. Beim Aufbau von Produktionsnetzen wurde daher die Suche nach Produktentwicklern, Konstrukteuren und Arbeitsplanern entweder ausgeklammert oder durch Erfahrungswissen außerhalb technischer Systeme realisiert. In diesem Artikel wird ein Beschreibungsmodell vorgestellt, welches es ermöglicht, planerische Kompetenzen darzustellen und geeignet zu verwalten. Weiterhin werden auf dieser Basis eine Spezifikation von Anforderungen und ein Abgleichsmechanismus präsentiert. Das hier skizzierte System kann damit beim Aufbau von Produktionsnetzen die Suche nach geeigneten Planern unterstützen und eine Entscheidungshilfe bieten.

Obstacles for neural network application in the ICIx database index

Presents the idea and first results of using GNG networks for hierarchical cluster analysis in order to create index structures for data management systems. It describes the creation procedure of a multi-dimensional index structure, the Intelligent Cluster Index (ICIx). In particular critical design decisions and tradeoffs between index efficiency and the neural networks clustering solution are discussed.

On Ensuring Lower Bounds of Negotiation Results

Employing software agents in tasks of electronic commerce where monetary values are negotiated and possibly exchanged by the agents autonomously, rises the question about the reliability of the agents. A human client expects his authorized agent to perform its tasks stable, reliable and safe, i.e. the agent should neither crash nor behave unpredictable in unexpected situations. It should always pursue the best possible deal and should be highly immune against fraud. We have developed an intelligent, adaptive agent model for integrative negotiations and show the stability of the model’s behaviour, the reliability of guaranteed negotiation results and the insusceptibility against possible manipulations and fraud.