Waldemar Wieczerzycki

Transaction Management in Databases Supporting Collaborative Applications

In the paper a particular approach to transaction management in databases supporting collaborative applications is proposed. It is based on a new transaction model which allows practically unrestricted collaboration among members of the same team. The basic assumption of this model is that collaborating users try to solve their access conflicts on a higher level than the level of a database management system. Users are not mutually isolated, as it happens in classical databases. They can freely negotiate, presenting their intentions concerning future work. The proposed approach was verified in Agora prototype which is a Web-based conferencing system, offering conference participants a flexible tool for collaborative document writing. Agora is implemented on the top of Oracle RDBMS.

Polymorphic agent clusters: the concept to design multi-agent environments supporting business activities

There are two main contributions of the work reported in the paper. First, a new model of software agents is proposed that are polymorphic and highly mobile. The former feature of agents results from the existence of potentially many agent versions. The latter feature is implied by the fact that only the necessary agent code is transmitted through the network, while the rest is transmitted only on demand.. Second, in the paper a particular approach to develop and manage multi-agent environments is proposed. It is based on so called agent clusters which group agents that mutually cooperate to perform a particular mission, e.g. to build and manage supply chains, to negotiate details of orders, to sign business contract. The approach seems to be straightforward, on one hand, and allows practically unrestricted collaboration among agents of the same business party, and safe cooperation among different business parties, on the other hand. The concept of agent cluster is inspired to some extent by the database technology, in particular by database transaction management.

Dynamic Configuration and Management of e-Supply Chains Based on Internet Public Registries Visited by Clusters of Software Agents

There are three main contributions of the work presented in this paper. First, a particular approach to develop and manage multi-agent environments is presented. It is based on so called agent clusters which group agents that mutually cooperate to perform a particular mission, e.g. to build and manage supply chains, to negotiate details of order. Second contribution is the presentation of public registry model. Authors have widened RosettaNet approach to public registries. Third, the integration of agent cluster model and public registry model is presented. New approach shows how agent technology can automate information exchange process within public registry.

Multiuser Transactions for Collaborative Database Applications

In the paper a particular approach to transaction management in databases supporting collaborative applications is proposed. It is based on a new transaction model which allows practically unrestricted collaboration among members of the same team. The basic assumption of this model is that collaborating users try to solve their access conflicts on a higher level than the level of a database management system. Users are not mutually isolated, as it happens in classical databases. They can freely negotiate, presenting their intentions concerning future work.

Version Support for CAD/CASE Databases

In the paper new functionalities for CADICASE databases are proposed which are necessary to improve the co-operative work of the design team members. These functionalities mainly concern versioning aspects of the design environments. First, typical project life-cycles are studied to determine the requirements for supporting efficient merge operation for different design environments. Next, the original extensions of so called database version model are proposed. Finally, the implementation of merge operation is discussed. All the functionalities mentioned above are currently implemented in the multiversion database prototype.

Improved E-sourcing Strategy with Multi-agent Swarms

The research results reported in this paper mainly relate to the well-known limitations of e-sourcing, i.e. the difficulties and restrictions in browsing thousands globally operating e-marketplaces, differences between the requirements of a potential participant for buying purposes and those of the organizations seeking participation as suppliers, growing competitiveness and the changeability of the demands at e-marketplaces. Combining agent technology with bee strategy offers a solution, as suggested in the paper. The behavior of bees, which cope with the management of limited resources in an unpredictable and constantly changing environment seems applicable to e-sourcing. This expands the present opportunities offered by e-marketplaces. The main contribution of this paper is an adaptation of the Polymorphic Self-Slimming Agent (PSA) model to the e-sourcing platform, which is based on the bees strategy. This combination shows how small and medium enterprises (SMEs) can significantly increase resources acquisition and search of potential suppliers.

A New Approach to Information Exchange within Public Registries Based on RosettaNet Standards

Small and medium enterprises (SMEs) frequently face big difficulties in joining e-commerce B2B networks. Often this is due to high entry costs and/or IT infrastructure requirements. The main contribution of the work presented in this paper is a new approach to RosettaNet B2B standards for SMEs. Our work is concentrated on information exchange model within so called public registries based on RosettaNet specifications. Registries built basing on the presented model can be used as a background for conducting B2B over Internet and building electronically managed supply chains or networks

Software reusability through versions

In this paper a new approach for modelling program variants (versions) is proposed, which is focused on increasing the level of software reuse, rather than on enriching data model. In this approach, a program is composed of a program body and a set of logically independent program contexts. The program body contains global functions and global data structures. Each program context contains exactly one variant of every class defined in the program and one variant of every non-global function, called a context function. Variants of the same class/function belonging to different contexts need not be different. During the program execution only one context is active. It may, however, be changed dynamically at program run-time. Thus, at a particular moment of time the program is viewed as a sum of the program body and exactly one program context.

Adaptation of extended polymorpohic self-slimming agent model into e-sourcing platform

There are two main contributions of the work presented in this paper. First, extended PSA agent model is described. It is based on two new properties of so called bootstrap agent: multiplication and parallelism. Second contribution is application of extended PSA model to e-sourcing platform. This duo (e-sourcing and extended PSA model) shows enterprises can significantly increase resources acquisition and potential suppliers search.

On hierarchical locking of composite objects

Abstract A stamp locking method is proposed, which is addressed to multiversion object-oriented databases. The method deals with all semantic relationships between objects and object versions in the database in uniform, hierarchical way. Hierarchical locking proposed does not require intentional locks.