Object-oriented Data Model Research Articles

Construction of Object Migration Behaviour Models from Temporal Constraints

A multi-aspects object data model enables multiple aspects of a real-world entity to be represented and to be acquired/lost dynamically. In multi-aspects object databases, object migration (OM) updating membership relationships between an object and classes occur, as the properties of the object evolve in its lifetime. Temporal object migration (TOM) behaviour modelling framework using coloured Petri nets (CPN) has been presented to construct TOM behaviour models, a temporally extended version of OM behaviour models. In manual construction of TOM behaviour models, however, it becomes more difficult to make the models consistent and complete as their scales grow larger. To overcome the problem, this paper proposes a technique for automatically constructing TOM behaviour models from TOM consistency constraints and class schemas, which are described in a concise, fragmentary, and declarative form.

An XML Schema integration and query mechanism system

The availability of large amounts of heterogeneous distributed web data necessitates the integration of XML data from multiple XML sources for many reasons. For example, currently, there are many e-commerce companies, which offer similar products but use different XML Schemas with possibly different ontologies. When any two such companies merge, or make an effort to service customers in cooperation, there is a need for an integrated schema and query mechanism for the interoperability of applications. In applications like comparison-shopping, there is a need for an illusionary centralized homogeneous information system. In this paper, we propose XML Schema integration and querying methodology. We define an object-oriented data model called XSDM (XML Schema Data Model) and present a graphical representation of XML Schema for the purpose of schema integration. We use a three-layered architecture for XML Schema integration. The three layers included are namely pre-integration, comparison, and integration. The three layers can conceptually be regarded as three phases of the integration process. During pre-integration, the schemas present in XML Schema notation are read and converted into the XSDM notation. During the comparison phase of integration, correspondences as well as conflicts between elements are identified. During the integration phase, conflict resolution, restructuring and merging of the initial schemas takes place to obtain the global schema. We define integration policies for integrating element definitions as well as their datatypes and attributes. An integrated global schema forms the basis for querying a set of local XML documents. We discuss various strategies for rewriting the global query over the global schema into the sub-queries over local schemas. Their respective local schemas validate the sub-queries over the local XML documents. This requires the identification and use of mapping rules and relationships between the local schemas.

A virtual type for a multiple‐type object and its implementation

AbstractTo deal with the evolution of data and applications and with the existence of multiple views for the same data, the object data model needs to be extended with the object extension functionality to allow an object to dynamically change its type, and the object viewing functionality to allow an object to be seen as if it had a different structure and behavior. This paper proposes the virtual type facility which provides a persistent object of ?, an enhanced C++ persistent programming language compliant with the ?standard, with a different structure and behavior from those of its base types. Additionally, it presents the implementation details of the facility. The virtual type facility gives a different interface of an object to redefine its structure and behavior without affecting the behavior of a base type, while the multiple‐type object of ?allows an object to be dynamically extended to model an entity which changes its behavior with time. The virtual type facility integrates the object extension functionality and the object viewing functionality for dealing with the database evolution. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(11): 25–35, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20781

Implementation of an object oriented data model in an information system for water catchment management: Java JDO and Db4o Object Database

Object-oriented technologies are playing increasingly important roles in every level of software application for water resource management and modelling, except for data management levels where the relational logic is still the uncontested choice of information system developers despite the object–relational impedance mismatch. In this paper, we would like to present our experience concerning two different technologies for developing the object-oriented data management layer in information systems for water resources management: (i) the Java solution to obtain transparent persistence, the Java Data Object (JDO) technology; (ii) a purer object solution with a light open source Object Database, Db4o. The process for implementing the two technologies in a Java-based hydro-information system is described, and the two different solutions were analysed and compared.

Design and implementation of an effective information system for Nigerian universites

The population explosion in Nigeria Universities even in the second generation Universities like the University of Port Harcourt has brought its own attendant problems in terms of handling student records and in the computation of results to accertain the true positions of students. Such records and computation of results are needed for the graduation of students. In view of these, there is the need to design and implement an effective information system for Nigerian Universities. In the development of this system various data object models were used such as the Data Access Object as well as the latest Microsoft technology for database management, the ActiveX Data Object. The implementation is done using Microsoft Visual Basic With the developed system, it is possible to add, delete, update or edit records in the database. Range searches as well as the use of wildcard character are supported by the system. Various reports are produced such as student progress score sheets, probation list, withdrawal list, as well as final graduation list. The system has been tested using student results in the department of Chemical Engineering, Faculty of Engineering, University of Port Harcourt. The computer resources required to use this system are: windows 98 and above, 16 MB RAM with a minimum hard disk space of 113.40 MB. Keywords: Information System; System Design; Nigerian UniversitiesJournal of Modeling, Design and Management of Engineering Systems, Vol. 3 (1) 2005: pp. 39-51

GIS as an information technology framework for water modeling

The sustainable and equitable management of water requires integrated analysis which includes the integration of a multitude of modeling systems at the core. The linkage of the modeling systems and components is the main bottleneck to achieve the integrated modeling solutions that maintain the integrity of the entire environmental system for comprehensive analysis, planning and management. In this paper, the use of a Geographic Information System (GIS), as an integration framework for the water modeling systems, together with object-oriented data modeling and programming schemes is explained. Integration of the modeling systems on a GIS platform, through a surface-water-specific GIS data model, Arc Hydro, and interface data models as data repositories for common water features, hydrologic and hydraulic modeling elements, is presented with a case study. Arc Hydro served as an integration data model for the simulation models of concern. Time series data transfer between modeling system at the information exchange points is facilitated using object-oriented linkage programs, and relationships among the modeling elements are established through Arc Hydro. In the case study, the HEC-HMS hydrologic model and the HEC-RAS hydraulic model are integrated into an automated floodplain mapping application on a GIS. The implementation of the integration methodology is presented.

A hybrid object based model combining probability and fuzzy set theories

Although there have been many fuzzy object-oriented data model proposed, and a bit less for probabilistic ones, models combining the relevance and strength of both fuzzy set theory and probability theory appear to be sporadic. This paper introduces our extension of Eiter et al.'s probabilistic object base model with two key features: uncertain and imprecise attribute values are represented as probability distributions on a set of fuzzy set values; class methods with uncertain and imprecise input and output arguments are formally integrated into the new model. A probabilistic interpretation of relations on fuzzy set values is proposed for their combination with probability degrees. Then the syntax and semantics of fuzzy-probabilistic object base schemas, instances, and selection operation are defined.

The Viewpoint Mechanism for Object-oriented Databases Modelling, Distribution and Evolution

During the past years, the most of research works dealing with the object multiple representation and evolution propose to enrich the monolithic vision of the classical object approach in which an object belongs to one hierarchy class. In particular, the viewpoint concept receives recently a widespread attention. Its integration to a data model gives flexibility for the conventional object-oriented data model and allows one to improve the modelling power of objects. The viewpoint paradigm can be used as a means for object multiple descriptions and as a means to master the complexity of the current database systems permitting a distributed manner to develop them. The motivation of this paper is twofold: to define an object data model integrating viewpoints in databases and to present a federated database system integrating multiple sources following a local-as-extended-view approach.

ARIA2: Automated NOE assignment and data integration in NMR structure calculation

Modern structural genomics projects demand for integrated methods for the interpretation and storage of nuclear magnetic resonance (NMR) data. Here we present version 2.1 of our program ARIA (Ambiguous Restraints for Iterative Assignment) for automated assignment of nuclear Overhauser enhancement (NOE) data and NMR structure calculation. We report on recent developments, most notably a graphical user interface, and the incorporation of the object-oriented data model of the Collaborative Computing Project for NMR (CCPN). The CCPN data model defines a storage model for NMR data, which greatly facilitates the transfer of data between different NMR software packages. A distribution with the source code of ARIA 2.1 is freely available at http://www.pasteur.fr/recherche/unites/Binfs/aria2.

MASCOT HTML and XML parser: An implementation of a novel object model for protein identification data

Protein identification using MS is an important technique in proteomics as well as a major generator of proteomics data. We have designed the protein identification data object model (PDOM) and developed a parser based on this model to facilitate the analysis and storage of these data. The parser works with HTML or XML files saved or exported from MASCOT MS/MS ions search in peptide summary report or MASCOT PMF search in protein summary report. The program creates PDOM objects, eliminates redundancy in the input file, and has the capability to output any PDOM object to a relational database. This program facilitates additional analysis of MASCOT search results and aids the storage of protein identification information. The implementation is extensible and can serve as a template to develop parsers for other search engines. The parser can be used as a stand-alone application or can be driven by other Java programs. It is currently being used as the front end for a system that loads HTML and XML result files of MASCOT searches into a relational database. The source code is freely available at http://www.ccbm.jhu.edu and the program uses only free and open-source Java libraries.

Rules for Migrating from Entity Relationship (ER) Diagrams to Object Relationship (OR) Diagrams

In this paper, we provide detailed mapping rules (a methodology) to convert an ER schema into an object relationship (OR) schema. The mapping rules are presented in a manner that will keep as much of the semantics of the database intact, in order to smoothen the important step of data migration from an ER schema to an OR schema. This OR schema should also serve as a conceptual design tool for object-oriented data models, very much like the ER diagrams are a conceptual design tool for relational databases. Since we are mainly discussing the conversion from an ER model to an OR model, we are limiting the discussion in this paper to the structural aspects of the OR model.

Functional and multivalued dependencies in nested databases generated by record and list constructor

The impact of the list constructor on two important classes of relational dependencies is investigated. Lists represent an inevitable data structure whenever order matters and data is allowed to occur repeatedly. The list constructor is therefore supported by many advanced data models such as genomic sequence, deductive and object-oriented data models including XML. The article proposes finite axiomatisations of functional, multivalued and both functional and multivalued dependencies in nested databases supporting record and list constructor. In order to capture different data models at a time, an abstract algebraic approach based on nested attributes is taken. The presence of the list constructor calls for a new inference rule which allows to infer non-trivial functional dependencies from multivalued dependencies. Further differences to the relational theory become apparent when the independence of the inference rules is investigated. The extension of the relational theory to nested databases allows to specify more real-world constraints and increases therefore the number of application domains.

A multi-level architecture for distributed object bases

The work described in this article arises from two needs. First, there is still a need for providing more sophisticated database systems than just relational ones. Secondly, there is a growing need for distributed databases. These needs are addressed by fragmenting schemata of a generic object data model and providing an architecture for its implementation. Key features of the architecture are the use of abstract communicating agents to realise database transactions and queries, the use of a remote object call mechanism to enable remote agents to communicate with one another, and the use of multi-level transactions. Linguistic reflection is used to map database schemata to the level of the agents. Transparency for the users is achieved by using dialogue objects, which are extended views on the database.

A Framework for Management of Semistructured Probabilistic Data

This paper describes the theoretical framework and implementation of a database management system for storing and manipulating diverse probability distributions of discrete random variables with finite domains, and associated information. A formal Semistructured Probabilistic Object (SPO) data model and a Semistructured Probabilistic Query Algebra (SP-algebra) are proposed. The SP-algebra supports standard database queries as well as some specific to probabilities, such as conditionalization and marginalization. Thus, the Semistructured Probabilistic Database may be used as a backend to any application that involves the management of large quantities of probabilistic information, such as building stochastic models. The implementation uses XML encoding of SPOs to facilitate communication with diverse applications. The database management system has been implemented on top of a relational DBMS. The translation of SP-algebra queries into relational queries are discussed here, and the results of initial experiments evaluating the system are reported.

Reasoning on UML class diagrams

UML is the de-facto standard formalism for software design and analysis. To support the design of large-scale industrial applications, sophisticated CASE tools are available on the market, that provide a user-friendly environment for editing, storing, and accessing multiple UML diagrams. It would be highly desirable to equip such CASE tools with automated reasoning capabilities, such as those studied in Artificial Intelligence and, in particular, in Knowledge Representation and Reasoning. Such capabilities would allow to automatically detect relevant formal properties of UML diagrams, such as inconsistencies or redundancies. With regard to this issue, we consider UML class diagrams, which are one of the most important components of UML, and we address the problem of reasoning on such diagrams. We resort to several results developed in the field of Knowledge Representation and Reasoning, regarding Description Logics (DLs), a family of logics that admit decidable reasoning procedures. Our first contribution is to show that reasoning on UML class diagrams is EXPTIME-hard, even under restrictive assumptions; we prove this result by showing a polynomial reduction from reasoning in DLs. The second contribution consists in establishing EXPTIME-membership of reasoning on UML class diagrams, provided that the use of arbitrary OCL (first-order) constraints is disallowed. We get this result by using DLR ifd , a very expressive EXPTIME-decidable DL that has been developed to capture typical features of conceptual and object-oriented data models. The last contribution has a more practical flavor, and consists in a polynomial encoding of UML class diagrams in the DL ALCQI , which essentially is the most expressive DL supported by current state-of-the-art DL-based reasoning systems. Though less expressive than DLR ifd , the DL ALCQI preserves enough semantics to keep reasoning about UML class diagrams sound and complete. Exploiting such an encoding, one can use current DL-based reasoning systems as core reasoning engines for a next generation of CASE tools, that are equipped with reasoning capabilities on UML class diagrams.

Design and Implementation of the Hydrographic Production and Management Information System (HYPAMIS)

With the development of hydrographic work and information techniques, the traditional work mode is not suitable for the Chinese Marine Safety Administration Bureau (CMSAB). Aiming at the separation of charts production and management, a new idea that is the integration of production, management, and quality control is presented. Geographic Information System (GIS), Management Information System (MIS), Office Automation (OA) and Spatial Database Management (SDM) advanced techniques are introduced into the workflows in CMSAB. To realize information sharing, a mixed mode with Browser/Server (B/S) mode and Client/Serve (C/S) mode are adopted. Based on the above ideas and strategies, an integrated system named Hydrographic Production And Management Information System (HYPAMIS) was developed. The whole workflow and three subworkflows including survey management workflow, production workflow, and quality control workflow of are outlined after re-engineering the CMSAB organization. Some design principles and key techniques of the HYPAMIS including the cooperation of GIS and MIS, object-oriented spatial data model and management, data management based on database, and security control are illustrated in detail. Then the implementation of the system is introduced briefly. Finally, performance evaluation of the system and future work is given.

Component-based topological data model for three-dimensional geology modeling

On the study of the basic characteristics of geological objects and the special requirement for computing 3D geological model, this paper gives an object-oriented 3D topologic data model. In this model, the geological objects are divided into four object classes: point, line, area and volume. The volume class is further divided into four subclasses: the composite volume, the complex volume, the simple volume and the component. Twelve kinds of topological relations and the related data structures are designed for the geological objects.

Viewpoints: a framework for object oriented database modelling and distribution

The viewpoint concept has received widespread attention recently. Its integration into a data model improves the flexibility of the conventional object-oriented data model and allows one to improve the modelling power of objects. The viewpoint paradigm can be used as a means of providing multiple descriptions of an object and as a means of mastering the complexity of current database systems enabling them to be developed in a distributed manner. The contribution of this paper is twofold: to define an object data model integrating viewpoints in databases and to present a federated database system integrating multiple sources following a local-as-extended-view approach.

Mapping care processes within a hospital: from theory to a web-based proposal merging enterprise modelling and ISO normative principles

Today, the economic and regulatory environment, involving activity-based and prospective payment systems, healthcare quality and risk analysis, traceability of the acts performed and evaluation of care practices, accounts for the current interest in clinical and hospital information systems. The structured gathering of information relative to users' needs and system requirements is fundamental when installing such systems. This stage takes time and is generally misconstrued by caregivers and is of limited efficacy to analysts. We used a modelling technique designed for manufacturing processes (IDEF0/SADT). We enhanced the basic model of an activity with descriptors extracted from the Ishikawa cause-and-effect diagram (methods, men, materials, machines, and environment). We proposed an object data model of a process and its components, and programmed a web-based tool in an object-oriented environment. This tool makes it possible to extract the data dictionary of a given process from the description of its elements and to locate documents (procedures, recommendations, instructions) according to each activity or role. Aimed at structuring needs and storing information provided by directly involved teams regarding the workings of an institution (or at least part of it), the process-mapping approach has an important contribution to make in the analysis of clinical information systems.

Creating and Implementing MS Office Security

The preeminence of MS Office in terms of functionality arrived with Office 95. That version was sufficiently functional to perform most desktop office processing and management tasks. However, its then-new document structures based on an object data model since used in all future versions created the security lapses addressed in this article. Feature and functional advances since Office 95 clearly have value, but are increasingly aimed at workflow efficiency and integration; Microsoft Corporation is positioning Office as a platform for delivery of new services within a collaborative environment. Although security is a stated strategic objective for Microsoft, a lack of fundamental data security undermines all of its products. As such, MS Office represents a critical commercial off-the-shelf (COTS) platform, albeit with a significant inherent risk because of workflows and object data model design flaws.