Cooperative Information Systems Research Articles

Experience-based knowledge management: a cooperative information systems perspective

Abstract Experience-based knowledge management is the art of capitalizing on failures and missed opportunities. Building on a number of interdisciplinary research projects, we study three possible approaches within a cooperative information systems framework, focussing on the facets of pragmatic technology usage, model-based management control, and social work practice and learning, respectively.

Improving data access in P2P systems

The authors present Gridella, a Gnutella-compatible P2P system. Gridella is based on the Peer-Grid (P-Grid) approach, which draws on research in distributed and cooperative information systems to provide a decentralized, scalable data access structure. Gridella improves the highly chaotic and inefficient Gnutella infrastructure with directed search and advanced concepts, thus enhancing efficiency and providing a model for further analysis and research.

AN EVALUATION OF THE JAVA-BASED APPROACHES TO WEB DATABASE ACCESS

Given the undeniable popularity of the Web, providing efficient and secure access to remote databases using a Web browser is crucial for the emerging cooperative information systems and applications. In this paper, we evaluate all currently available Java-based approaches that support persistent connections between Web clients and database servers. These approaches include Java applets, Java Sockets, Servlets, Remote Method Invocation, CORBA, and mobile agents technology. Our comparison is along the dimensions of performance and programmability. Our findings point out that best performance is not always achievable with high programmability and low resource requirements. Moreover, the mobile agent technology needs to improve its programmability while giving particular emphasis on its infrastructure.

Seamless cooperative information systems [Book Review

Seamless cooperative information systems [Book Review

A uniform methodology for extracting type conflicts and subscheme similarities from heterogeneous databases

Cooperative Information Systems have been proposed to allow a uniform access to heterogeneous data yet preserving their operational autonomy. They use global dictionaries defined on the basis of interscheme properties; these include nominal and structural properties, type conflicts and object cluster similarities. Whereas in the literature a certain number of techniques has been proposed for deriving nominal and structural properties, few approaches exist for detecting type conflicts and object cluster similarities. The type of an object indicates if it is an entity, a relationship or an attribute; type conflicts indicate the existence of objects representing the same concept yet having different types. Object cluster similarities denote similitudes between portions of different schemes. This paper proposes an automatic, probabilistic approach to the detection of type conflicts and object cluster similarities in database schemes. The method we are proposing here is based on considering pairs of objects having different types (resp., pairs of clusters), belonging to different schemes and on measuring their similarity. To this purpose object (resp., cluster) structures as well as object (resp., cluster) neighborhoods are analyzed to verify similitudes and differences. A number of examples shows the suitability of our techniques to effectively detect type conflicts and object cluster similarities.

Experience-Based Knowledge Management

Experience-based knowledge management is the art of capitalizing on failures and missed opportunities. We study three possible approaches within a cooperative information systems framework, building on a number of interdisciplinary research projects.

TOGA—A customizable service for Data-Centric collaboration

Collaboration in cooperative information systems, like concurrent design and engineering, exploits common work and information spaces. In this paper we introduce the TOGA service (Transaction-Oriented Group and Coordination Service for Data-Centric Applications), which offers group management facilities and a push model for change propagation w.r.t. shared data, thus allowing for group awareness. Through TOGA's customizability and its layered architecture the service can be adapted to a variety of different collaboration scenarios. Multiple communication protocols (CORBA, UDP/IP, TCP/IP) are supported as well as basic transaction properties. Our approach enables both, firstly, the evolution of a set of separate applications to form a cooperative information system, i.e., it provides a technique towards component-oriented system engineering. Secondly, it can be exploited as a basic service within collaboration frameworks to effectively manage common work and information spaces. In this paper we report on design issues, implementation aspects, and first experiences gained with the TOGA prototype and its exploitation in an activity coordination and collaboration framework system.

A logical approach to cooperative information systems

“Cooperative information system management” refers to the capacity of several computing systems to communicate and cooperate in order to acquire, store, manage, query data and knowledge. Current solutions to the problem of cooperative information management are still far from being satisfactory. In particular, they lack the ability to fully model cooperation among heterogeneous systems according to a declarative style. The use of a logical approach to model all aspects of cooperation seems very promising. In this paper, we define a logical language able to support cooperative queries, updates and update propagation. We model the sources of information as deductive databases, sharing the same logical language to express queries and updates, but containing independent, even if possibly related, data. We use the Obj-U-Datalog (E. Bertino, G. Guerrini, D. Montesi, Toward deductive object databases, Theory and Practice of Object Systems 1 (1) (1995) 19–39) language to model queries and transactions in each source of data. Such language is then extended to deal with active rules in the style of Active-U-Datalog (E. Bertino, B. Catania, V. Gervasi, A. Raffaetà, Active-U-Datalog: Integrating active rules in a logical update language, in: B. Freitag, H. Decker, M. Kifer, A. Voronkov (Eds.), LBCS 1472: Transactions and Change in Login Databases, 1998, pp. 106–132; V. Gervasi, A. Raffaetà, Active-U-Datalog: Integrating Active Rules in a Deductive Database, Technical Report 97–19, Dipartimento di Informatica, Pisa, Italy, 1997), interpreted according to the PARK semantics proposed in G. Gottlob, G. Moerkotte, V.S. Subrahmanian (The PARK semantics for active rules, in: P.M.G. Apers, M. Bouzeghoub, G. Gardarin (Eds.), LNCS 1057: Proceedings of the Fifth International Conference on Extending Database Technology, 1996, pp. 35–55). By using active rules, a system can efficiently perform update propagation among different databases. The result is a logical environment, integrating active and deductive rules, to perform update propagation in a cooperative framework.

METHODOLOGY AND CASE TOOLS FOR THE DEVELOPMENT OF FEDERATED DATABASES

Due to the current technological and economical context, there is an increasing need for cooperating information systems based on federated databases. Though the technical issues of these architectures have been studied for long, the way to build them has not triggered as much effort. This paper describes a general architecture, a methodology and a CASE environment intended to address the problem of providing users and programmers with an abstract interface to independent heterogeneous and distributed databases. The architecture comprise a hierarchy of mediators and a repository that dynamically transform actual data into a virtual homogeneous database and allow client applications to query it. The InterDB approach provides a complete methodology to define this architecture, including schema recovery through reverse engineering, database integration and mapping building. The methodology is supported by the DB-MAIN CASE tool that helps developers generate the mediators and their repository.

Export database derivation in object-oriented wrappers

Wrappers export the schema and data of existing heterogeneous databases and support queries on them. In the context of cooperative information systems, we present a flexible approach to specify the derivation of object-oriented (OO) export databases from local relational databases. Our export database derivation consists of a set of extent derivation structures (EDS) which defines the extent and deep extent of export classes. Having well-defined semantics, the EDS can be readily used in transforming wrapper queries to local queries. Based on the EDS, we developed a wrapper query evaluation strategy which handles OO queries on the export databases. The strategy is unique in that it considers the limited query processing capabilities of local database systems as well as the language constraints on the local query languages.

Integrating HIS-RIS-PACS: the Freiburg experience.

With the integration of different formerly isolated information systems, such as Hospital Information System (HIS). Radiology Information System (RIS), Picture Archiving and Communication System (PACS) and modalities, we evolve towards an architecture of distributed information processing in radiology, the data being stored in distributed databases. The frontier between the cooperative information systems becomes more subtle than in the past, and it seems more convenient to distinguish the different computer functionalities or services used in radiology than to detail the functions of RIS and PACS. This paper opens with a description of the different computer services used in radiology and how they relate one to another. It also shows how these functionalities could be integrated within a global Radiology Information and Archiving System. Finally, it shows the degree of systems interconnection that can be achieved presently, using the PACS-RIS installation at the University Hospital of Freiburg as an example.

Reconstruction of cooperative information systems under cost constraints: A rough set approach

Bazan et al. have proposed a method for synthesis of cooperative information systems specified by data tables (information systems). The basic idea of the method concerns a decomposition of data table into functional components (modules) linked by communication lines (communications). On the basis of this method Suraj elaborated a strategy for reconstruction of the synthetized cooperative information system when the specification for the system is changing e.g. by adding new requirements. The strategy allows us to produce a plan of reconstruction of a given system by specifying which parts (modules and communications) can remain unchanged and which must be changed to satisfy new requirements. The aim of the paper is to present an approach for the reconstruction of the synthetized system under cost constraints. The cost of the reconstruction is treated as the cost of adding new functional modules, communication lines or their modifications. It is estimated with respect to any reduct and any covering in both systems i.e. in a given system and a reconstructed one. In fact, we define a new concept concerning the cost of a rule mentioned as the sum of the costs of attributes on the left-hand side of the rule. We assume that an information system representing data table together with a vector of attribute costs are given. The attribute cost can be interpreted e.g. the time of the measurement of its concrete value. We give also a simple example illustrating our approach as well as some information about a computer system for supporting the process of construction and/or reconstruction of a given cooperative information system specified by an information system. Our approach is based on rough set theory and it can be applied in the system technology domain to adaptive reorganization of existing cooperative information systems.

A user‐centered cooperative information system for medical imaging diagnosis

Computer-supported cooperative work (CSCW) is one of the most promising technologies aimed to assist medical users located in different clinical sites to access distributed medical imaging information. This article presents a cooperative information system intended for remote medical imaging diagnosis. The main general CSCW problems addressed here are as follows: (1) At a conceptual level: The definition of a procedure for the design of user-centered cooperative systems; and (2) at a technological level: The improvement of user feedback and the optimization of the communication bandwidth in highly interactive CSCW applications for remote access to medical image databases. These technological goals are achieved by developing two main components: A CSCW distributed architecture for synchronous cooperative work and a DICOM medical image database management system. A cooperative system in the field of cardiac angiography images has allowed us to test and validate the user-centered design procedures and the CSCW architectures implemented. Finally, a discussion of experience of the user-centered design and of the implementation of cooperative information systems is also presented. © 1998 John Wiley & Sons, Inc.

ENFORCEMENT OF INTER-TASK DEPENDENCIES IN WORKFLOWS, CHARACTERIZATION AND PARADIGM

Workflow techniques have gained a lot of attention as a means to support advanced business applications such as cooperative information systems and process re-engineering but also as a means to integrate legacy systems. Inter-task dependencies, described separately from the other parts of the workflow, have been recognized as a valuable method in describing certain restrictions on the executions of workflows. In this paper, we study the issue of pre-analysing and enforcing inter-task dependencies. The protocol and the theory behind it are presented, along with examples and discussions on ways to improve the performance. The idea is to present the meaning of a dependency through an automaton which accepts the sequences of events tied by the dependency through an automaton which accepts the sequences of events tied by the dependency. We prune from the automata certain paths that cannot be followed due to the conflicting paths in other automata and record the feasible event sequences in a special data structure to be used during run-time. We show the correctness of the algorithms and also show that our run-time algorithm is linear, whereas the original approach suggested by MCC in Refs. 5 and 6 is exponential, when resolution of one event is concerned.

MERGING DATABASES UNDER CONSTRAINTS

The problem of integrating information from conflicting sources comes up in many current applications, such as cooperative information systems, heterogeneous databases, and multiagent systems. We model this by the operation of merging first-order theories. We propose a formal semantics for this operation and show that it has desirable properties, including abiding by majority rule in case of conflict and syntax independence. We apply our semantics to the special case when the theories to be merged represent relational databases under integrity constraints. We then present a way of merging databases that have different or conflicting schemas caused by problems such as synonyms, homonyms or type conflicts mentioned in the schema integration literature.

A user-centered cooperative information system for medical imaging diagnosis

Computer-supported cooperative work (CSCW) is one of the most promising technologies aimed to assist medical users located in different clinical sites to access distributed medical imaging information. This article presents a cooperative information system intended for remote medical imaging diagnosis. The main general CSCW problems addressed here are as follows: (1) At a conceptual level: The definition of a procedure for the design of user-centered cooperative systems; and (2) at a technological level: The improvement of user feedback and the optimization of the communication bandwidth in highly interactive CSCW applications for remote access to medical image databases. These technological goals are achieved by developing two main components: A CSCW distributed architecture for synchronous cooperative work and a DICOM medical image database management system. A cooperative system in the field of cardiac angiography images has allowed us to test and validate the user-centered design procedures and the CSCW architectures implemented. Finally, a discussion of experience of the user-centered design and of the implementation of cooperative information systems is also presented. © 1998 John Wiley & Sons, Inc.

All agents are not created equal

As the technology advances, we can expect the development of specialized agents to be used as standardized building blocks for information systems. Two trends lend credence to such a prediction. First, software systems in general are being constructed with larger components, such as ActiveX and JavaBeans, which are becoming closer to being agents themselves. They have more functionality than simple objects, respond to events autonomously, and, most importantly, respond to system builders at development time, as well as to events at runtime. Moreover, there is a move toward more cooperative information systems, in which the architecture itself plays an important role in the effectiveness of the system, as opposed to traditional software systems where effectiveness depends on the quality of the individual components. These architectures are generating a set of standardized agents. Architectures based on standardized agent types should be easier to develop, understand, and use. Perhaps most important of all, these architectures will make it easier for separately developed information systems to interoperate.

Extending Database Support for Coordination Among Agents

Coordination and collaboration are naturally used by groups for carrying out activities and solving problems that require cooperation. However, getting a set of computer agents to do the same has been a problem – primarily addressed by the AI community and recently by the database community as workflow and process management problems (for example, in business processes, electronic commerce, logistics). Not surprisingly, the problem has been addressed at different levels of abstraction by the two communities. Coordination protocols as well as task and result sharing have been investigated by the AI community; specification of alternative transaction models to meet the requirements of non-traditional applications, and their execution have been addressed by the database community. It is evident that there is a need for bringing the two approaches together to develop systems that support cooperative problem solving. This paper – argues for the use of active databases in general and active capability in particular as an enabling technology for cooperative problem solving and cooperative information systems – details a novel approach for supporting task sharing, a key aspect of CPS, using active capability – elaborates on a methodology for mapping task shared protocols expressed in high level speech acts to Event Condition-Action (ECA) rules.

FORMAL METHODS IN CIS: HETEROGENEOUS DATABASES GUEST EDITORS' INTRODUCTION

There has been much progress recently in cooperative information systems: new problems are being attacked, new techniques are being developed. As the field matures and as its applications become deployed in a wider range of domains and locales, there is increasing interest in formal methods to understand, analyze, design, verify, and validate cooperative information systems. Since the science of cooperative information systems (CIS) unabashedly borrows from several traditional disciplines, the techniques and formal methods that it applies are also of a wide variety. This issue presents some of the best papers in this subfield of CIS. These papers are unified by their relationship to heterogeneous databases and information environments. Even within this subset of CIS, it is interesting to see methods whose traditional counterparts are in artificial intelligence, software engineering, and database semantics and query processing. Lee, Madnick, and Siegel address one of the fundamental problems in CIS, namely, that of the semantic interoperability of information systems that arise in different contexts. Context is the holy grail of a number of sciences that deal with meaning. This paper proposes an approach that has many useful properties for enabling the exchange of information among diverse data sources. It models context and interoperation at the knowledge level, term coined by Allen Newell in artificial intelligence; it uses techniques pioneered by Ray Reiter, also in artificial intelligence. This enables an abstract characterization of the meaning of information independent of its specific realization in a particular system. Lee and Wu also concern themselves with the interoperability of autonomous databases. They propose hyperrelations—extended from the relations of traditional database theory—as a uniform and succinct means to represent the local schemas

A METHODOLOGY FOR QUERY REFORMULATION IN CIS USING SEMANTIC KNOWLEDGE

We consider Cooperative Information Systems (CIS) that are multidatabase systems (MDBMS), with a common object-oriented model, based on the ODMG standard, together with local databases that may be relational, object-oriented, or dedicated data servers. The MDBMS interface (or mediator interface) that describes this CIS could be different from the union of the local interfaces that describe each local database. In particular, the mediator interface may be defined by semantic knowledge that includes views over particular local databases, integrity constraints, and knowledge about data replication in local databases. We present a methodology for query reformulation which is based on the uniform representation of all semantic knowledge in the form of integrity assertions and mapping rules. A reformulation algorithm exploits this semantic knowledge, and performs semantic rewriting based on pattern-matching, to obtain a query on the union of the local interfaces. A decomposition algorithm then produces a composite query, and local sub-queries, one for each local interface. The reformulation is general enough to re-use the results of previously computed queries in the CIS. We have implemented this reformulation technique in our Flora compiler prototype which we used for validation and experimentation with O2 databases.