A lexical analyser for Arabic

Practical natural language processing (NLP) systems such as database front-ends, deductive databases or object-oriented databases are at the forefront of research into the next-generation intelligent database systems. The research described in this paper has been aimed at integrating front-end paradigms and rule-based deduction to provide a single powerful framework for database systems in Arabic. The lexicon stores only roots of verbs and uses a program intelligent enough to handle all derived forms automatically. This is significant, as these alone represent 70% of the total dictionary. As part of the discussion of this system, its utility in such NLP applications as parsing and machine translation is examined.     

面向对象数据库技术在电子商务中的应用

面向对象（Object—Oriented,OO）数据库系统是数据库与OO技术相结合的产物,作为一种新型的数据库系统,它不仅拥有基本功能,而且支持面向对象的数据模型。本文结合了电子商务系统,阐述了面向对象的数据库。重点研究了面向对象数据库系统在电子商务中的应用,并对其设计思想、软件架构、对象操作及布置等做了较为深入的介绍和技术探讨。     

Formal approach for reengineering fuzzy XML in fuzzy object-oriented databases

Since semi-structured documents (e.g., XML) could benefit greatly from database support and more specifically from object-oriented (OO) database management systems, we study the methodology of reengineering XML to object-oriented databases when database migration occurs in this paper. In particular, considering the need of processing the imprecise and uncertain information existing in practical applications, we investigate the problem of migrating fuzzy XML to fuzzy object-oriented databases. To find the object-oriented schema that best describes the existing fuzzy XML schema (DTD), we devise a comprehensive approach centering on a set of mapping rules. Such reengineering practices could not only provide a significant consolidation of the interoperability between fuzzy OO and fuzzy XML modeling techniques, but also develop the practical design methodology for fuzzy OO databases.     

The Pegasus heterogeneous multidatabase system

Pegasus, a heterogeneous multidatabase management system that responds to the need for effective access and management of shared data across in a wide range of applications, is described. Pegasus provides facilities for multidatabase applications to access and manipulate multipole autonomous heterogeneous distributed object-oriented relational, and other information systems through a uniform interface. It is a complete data management system that integrates various native and local databases. Pegasus takes advantage of object-oriented data modeling and programming capabilities. It uses both type and function abstractions to deal with mapping and integration problems. Function implementation can be defined in an underlying database language or a programming language. Data abstraction and encapsulation facilities in the Pegasus object model provide an extensible framework for dealing with various kinds of heterogeneities in the traditional database systems and nontraditional data sources     

Classifying schematic and data heterogeneity in multidatabasesystems

A complete framework for enumerating and classifying the types of multidatabase system (MDBS) structural and representational discrepancies is developed. The framework is structured according to a relational database schema and is both practical and complete. It was used to build the UniSQL/M commercial multidatabase system. This MDBS was built over Structured-Query-Language-based relational database systems and a unified relational and object-oriented database system named UniSQL/X. However, the results are substantially applicable to heterogeneous database systems that use a nonrelational data model (for example, an object-oriented data model) as the common data model and allow the formulation of queries directly against the component database schemas     

Teamwork support in a knowledge-based information systemsenvironment

Development assistance for interactive database applications (DAIDA) is an experimental environment for the knowledge-assisted development and maintenance of database-intensive information systems from object-oriented requirements and specifications. Within the DAIDA framework, an approach to integrate different tasks encountered in software projects via a conceptual modeling strategy has been developed. Emphasis is put on integrating the semantics of the software development domain with aspects of group work, on social strategies to negotiate problems by argumentation, and on assigning responsibilities for task fulfillment by way of contracting. The implementation of a prototype is demonstrated with a sample session     

Graph-Based Parallel Query Processing and Optimization Strategies for Object-Oriented Databases

Much work has been accomplished in the past on the subject of parallel query processing and optimization in parallel relational database systems; however, little work on the same subject has been done in parallel object-oriented database systems. Since the object-oriented view of a database and its processing are quite different from those of a relational system, it can be expected that techniques of parallel query processing and optimization for the latter can be different from the former. In this paper, we present a general framework for parallel object-oriented database systems and several implemented query processing and optimization strategies together with some performance evaluation results. In this work, multiwavefront algorithms are used in query processing to allow a higher degree of parallelism than the traditional tree-based query processing. Four optimization strategies, which are designed specifically for the multiwavefront algorithms and for the optimization of single as well as multiple queries, are introduced. The query processing algorithms and optimization strategies have been implemented on a parallel computer, nCUBE2; and the results of a performance evaluation are presented in this paper. The main emphases and the intended contributions of this paper are (1) data partitioning, query processing and optimization strategies suitable for parallel OODBMSs, (2) the implementation of the multiwavefront algorithms and optimization strategies, and (3) the performance evaluation results.     

A knowledge-based framework for intelligent-data migration

Abstract: The Object-Inferencing Framework (OIF) is a knowledge-based system developed for intelligent-data migration. The framework provides a mechanism to integrate relational data which represents a source model; a project-specific rulebase which specifies plausible migration scenarios; and a deduction system to facilitate the migration of source data to a new, complex target model. Typically, the target model includes constituents that possess both graphic and tabular components. Although the framework is experimental, industrial applications built upon OIF have been successfully deployed in scenarios in which the source data contained implicit information in that semantic relationships and structure conveyed by the data had to be inferred by a domain expert. This framework provides a substrate for migration from any unstructured or semi-structured data representation to a complex, semantically rich target data model. Examples of the migration of CAD data, which represents an electrical-distribution system, to a client-server based Automated Mapping/Facilities Management (AM/FM) platform are presented to convey the salient features of the design and utility of the OIF. Even though the examples are taken from a specific domain, the approach has potential applications in a myriad of domains, including business enterprises in which the migration of data created and managed by legacy systems to object-oriented and clientserver environments is an area of intense research and development.     

A fuzzy knowledge-based system for intelligent retrieval

For many knowledge-intensive applications, it is important to develop an environment that permits flexible modeling and fuzzy querying of complex data and knowledge including uncertainty. With such an environment, one can have intelligent retrieval of information and knowledge, which has become a critical requirement for those applications. In this paper, we introduce a fuzzy knowledge-based (FKB) system along with the model and the inference mechanism. The inference mechanism is based on the extension of the Rete algorithm to handle fuzziness using a similarity-based approach. The proposed FKB system is used in the intelligent fuzzy object-oriented database (IFOOD) environment, in which a fuzzy object-oriented database is used to handle large scale of complex data while the FKB system is used to handle knowledge of the application domain. Both the fuzzy object-oriented database system and the fuzzy knowledge-based system are based on the object-oriented concepts to eliminate data type mismatches. The aim of this paper is mainly to introduce the FKB system of the IFOOD environment.     

面向对象设计中的O/R映射架构

O／R映射是当前基于关系型数据库应用的面向对象系统设计中的新问题，关系型数据库在一定程度上制约了应用系统面向对象设计的架构和灵活性。文中结合已有应用设计架构提出改进的缓冲工作元(Cache Worker)架构，用它可以在兼顾性能的基础上屏蔽关系型数据存储方式给面向对象系统设计带来的障碍，给系统设计更大的灵括性。     

Integrating relational and object-oriented database systems using a metaclass concept

This paper presents a specific approach of integrating a relational database system into a federated database system. The underlying database integration process consist of three steps: first, the external database systems have to be connected to the integrated database system environment and the external data models have to be mapped into a canonical data model. This step is often called syntactic transformation including structural enrichment and leads to component schemas for each external DBMS. Second, the resulting schemas from the first step are used to construct export schemas which are then integrated into global, individual schemas or views in the third step. In this paper we focus on the first step for relational databases, i.e., the connection of a relational database system and the mapping of the relational model into a canonical data model. We take POSTGRES as the relational database system and the object-oriented federated database system VODAK as the integration platform which provides the open, object-oriented data model as the canonical data model for the integration. We show different variations of mapping the relational model. By exploiting the metaclass concept provided by VML, the modelling language of VODAK, we show how to tailor VML such that the canonical data model meets the requirements of integrating POSTGRES into the global database system VODAK in an efficient way.     

Design of a multimedia object-oriented DBMS

The emerging multimedia information (such as video, image, voice, graphics) services have imposed many new requirements and research considerations on the design of database management systems (DBMSs). Conventionally, a multimedia DBMS is designed by developing a multimedia presentation layer on top of a pre-existing object-oriented DBMS (which can be truly object-oriented or relational-based), such that the core of the DBMS was developed earlier independent of the design of the multimedia presentation layer. Due to the fact that multimedia capabilities are not actually embedded in the DBMSs, such systems tend to provide only a rather limited set of functionalities in multimedia and are not satisfactory in supporting multimedia applications. This paper describes some key features of a multimedia object-oriented DBMS that is currently being developed. In this system the DBMS is carefully redesigned to provide special multimedia capabilities, such that the mismatch between the DBMS and the multimedia application layer can be eliminated. In particular, this paper will focus on unique multimedia capabilities including multimedia object modeling, video data management, and distributed collaboration. This project was supported in part by Rome Laboratory, U.S. Air Force under the contract no. F30602-94-C-0090     

Expert system methodologies and applications—a decade review from 1995 to 2004

This paper surveys expert systems (ES) development using a literature review and classification of articles from 1995 to 2004 with a keyword index and article abstract in order to explore how ES methodologies and applications have developed during this period. Based on the scope of 166 articles from 78 academic journals (retrieved from five online database) of ES applications, this paper surveys and classifies ES methodologies using the following eleven categories: rule-based systems, knowledge-based systems, neural networks, fuzzy ESs, object-oriented methodology, case-based reasoning, system architecture, intelligent agent systems, database methodology, modeling, and ontology together with their applications for different research and problem domains. Discussion is presented, indicating the followings future development directions for ES methodologies and applications: (1) ES methodologies are tending to develop towards expertise orientation and ES applications development is a problem-oriented domain. (2) It is suggested that different social science methodologies, such as psychology, cognitive science, and human behavior could implement ES as another kind of methodology. (3) The ability to continually change and obtain new understanding is the driving power of ES methodologies, and should be the ES application of future works.     

Schema evolution and integration

Providing support forschema evolution allows existing databases to be adjusted for varying roles over time. This paper reflects on existing evolution support schemes and introduces a more general and functional mechanism to support schema evolution andinstance adaptation for centralized and distributed object-oriented database systems. Our evolution support scheme is distinguished from previous mechanisms in that it is primarily concerned with preserving existing database objects and maintaining compatibility for old applications, while permitting a wider range of evolution operations. It achieves this by supporting schema versioning, allowing multiple representations of instances to persist simultaneously, and providing for programmer specification of how to adapt existing instances. The mechanism is general enough to provide much of the support necessarily forheterogeneous schema integration, as well as incorporating much of the features of object migration and replication.     

Representation of spatial data in an OODB using roughand fuzzy set modeling

This paper introduces and formally defines a fuzzy rough object-oriented database (OODB) model based on a formal framework using an algebraic type system and formally defined constraints. This generalized model incorporates both rough set and fuzzy set uncertainty, while remaining compliant with object-oriented database standards set forth by the Object Database Management Group. Rough and fuzzy set uncertainty enhance the OODB model so that it can more accurately model real world applications. Spatial databases have a particular need for uncertainty management that can be achieved through rough and fuzzy techniques.     

Providing Database Interoperability through Object-Oriented Language Constructs

Seamless access to resources and services provided by distributed, autonomous, and heterogeneous systems is central to many advanced applications. Building an integrated system to provide such uniform access and cooperation among underlying heterogeneous systems is both an increasing necessity and a formidable challenge. An important component of such a complex integrated system is a unified language that serves both as a data definition and as a data manipulation tool. Special requirements are posed in the instance of an integrated system which includes database systems among its components. In this paper, we introduce the necessary constructs that an object-oriented programming language should provide for being adopted as the language of the integrated system in such a setting. We adopt a modular, object-based approach to integration. Each component system that joins the integration provides a set of basic classes and pre-defined basic methods. We show how the class hierarchy of the system can be used to provide a uniform way of mapping database resources to basic classes and associative queries to basic methods. A view mechanism is introduced that supports the integration of the basic classes and provides a means of expressing relationships among them and resolving any potential conflicts. The view mechanism is implemented by extending the standard class constructors of an object-oriented language to support the definition of virtual classes. The language provides workflow constructs for defining the structure of programs and for attaining synchronization among concurrently executing programs. Furthermore, atomicity and concurrency control information is included in the form of consistency assertions as part of the interface of each basic method.     

Implementing a user interface management system for existing applications using an object-oriented database tool

Numerous engineering application systems have been developed over the past twenty years, and many of these applications will continue to be used for many years to come. Examples of such applications include CAD Systems, finite-element analysis packages and inspection systems. Because many of these applications were developed before graphical workstations became available, they often have simple command-line user interfaces. Thus, there is a need for a graphical user interface management system (UIMS) that can be used to build point-and-click style interfaces for these existing engineering applications. In this paper we describe such a UIMS, and discuss its implementation using an object-oriented database tool. This UIMS allows users to create and modify user interfaces by editing graphical representations of the interfaces, thus eliminating the need to write code to build or modify an interface. The UIMS is implemented using an object-oriented database tool to take advantage of the data manipulation and storage management capabilities it provides. This approach reduces both the quantity and complexity of the code needed to implement the UIMS. It also allowed the UIMS to be implemented in a minimal amount of time.     

EXACT: an extensible approach to active object-oriented databases

Active database management systems (DBMSs) are a fast-growing area of research, mainly due to the large number of applications which can benefit from this active dimension. These applications are far from being homogeneous, requiring different kinds of functionalities. However, most of the active DBMSs described in the literature only provide a fixed, hard-wired execution model to support the active dimension. In object-oriented DBMSs, event-condition-action rules have been propo sed for providing active behaviour. This paper presents EXACT, a rule manager for object-oriented DBMSs which provides a variety of options from which the designer can choose the one that best fits the semantics of the concept to be supported by rules. Due to the difficulty of foreseeing future requirements, special attention has been paid to making rule management easily extensible, so that the user can tailor it to suit specific applications. This has been borne out by an implementation in ADAM, an object -oriented DBMS. An example is shown of how the default mechanism can be easily extended to support new requirements. Edited by Y. Vassiliou. Received May 26, 1994 / Revised January 26, 1995, June 22, 1996 / Accepted November 4, 1996     

On the representation and management of medical records in a knowledge-based system

The need for adapting Hospital Information Systems (HISs) to new applications (aimed at clinical data management) and to the ever growing population requires an evolution from both the representation and the usability points of view. The goal of this paper is to discuss the interdependencies of the advanced data representation models necessary to the new HISs and the interaction requirements. In particular, we present the technical taken in the MILORD (Multimedia Interaction with Large Object-oriented Radiological and clinical Databases) project to implement a departmental environment which integrates different kinds of clinical data in a user-friendly and homogeneous way. The implementation platform of the MILORD system is based on results obtained in the KIWIS project, which produced an advanced knowledge-base environment for large database systems. The interaction with a HIS is analyzed identifying the HIS-specific interaction tasks, the typical phases of the interaction with an information system, and the necessary interaction paradigms. In particular we describe the approach adopted in KIWIS for overcoming the problem of querying object-oriented databases and we discuss the new requirements that multimediality poses on the interaction paradigms.     

An AGENDA for testing relational database applications

Database systems play an important role in nearly every modern organization, yet relatively little research effort has focused on how to test them. This paper discusses issues arising in testing database systems, presents an approach to testing database applications, and describes AGENDA, a set of tools to facilitate the use of this approach. In testing such applications, the state of the database before and after the user's operation plays an important role, along with the user's input and the system output. A framework for testing database applications is introduced. A complete tool set, based on this framework, has been prototyped. The components of this system are a parsing tool that gathers relevant information from the database schema and application, a tool that populates the database with meaningful data that satisfy database constraints, a tool that generates test cases for the application, a tool that checks the resulting database state after operations are performed by a database application, and a tool that assists the tester in checking the database application's output. The design and implementation of each component of the system are discussed. The prototype described here is limited to applications consisting of a single SQL query. Copyright © 2004 John Wiley & Sons, Ltd.