This paper describes the main characteristics involved in the process of using multimedia content in the Internet sites and it presents a proposal for an implementation of an object-oriented database, in order to assi...
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ISBN:
(纸本)9728865694
This paper describes the main characteristics involved in the process of using multimedia content in the Internet sites and it presents a proposal for an implementation of an object-oriented database, in order to assist the multimedia data exigency in a dynamic website. It is described an implementation of the proposed architecture, consisting of a virtual museum made for the Contemporary Art Museum of the USP, called Virtual MAC, which was elected as the 3(rd) best virtual museum of the world by INFOLAC Web 2005 (UNESCO). The main objective of Virtual MAC is to create a virtual collection of works at art and make it available on Internet. Our analysis shows that it is more appropriate to use the objectoriented paradigm instead of Relational Modelling due to the nature of the multimedia data and the structure of the dynamic web site used for the Virtual MAC.
The problem of how to maintain the consistent state of a database is one of the important issues in the research of database area. There have been several researches aimed at this problem for relational database since...
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ISBN:
(纸本)0976348616
The problem of how to maintain the consistent state of a database is one of the important issues in the research of database area. There have been several researches aimed at this problem for relational database since two decades ago. But for object-oriented database, which has more complex structure than relational database, there is a need to have a more general framework to discuss this problem from additional aspects in more elaborate manner. The purpose of this paper is to propose a theoretical model, including various aspect of consistency, the methods of checking consistency, and how to enforce consistency in object-oriented database
A new static optimization method in object query languages is presented. We introduce a special kind of subqueries of a query referred to as "weakly dependent subqueries". A subquery is weakly dependent if i...
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ISBN:
(纸本)9783642146800
A new static optimization method in object query languages is presented. We introduce a special kind of subqueries of a query referred to as "weakly dependent subqueries". A subquery is weakly dependent if it depends from an external query operator only on an expression returning the result of an enumerated type. If a query contains such subqueries then we rewrite it to an equivalent form which guarantees much better performance. Our method is based on the stack-based approach (SBA) and its query language SBQL (Stack-Based Query Language) implemented in the ODRA system. SBA is relevant for a general object model and for its specific variants. Clean formal semantics and abstract implementation of SBQL, integration with the constructs of programming languages and advanced data structures give the possibility to investigate different areas that are related to query optimization techniques. The paper presents examples how the optimization method works. General and detailed features of the implemented algorithm are also presented.
Collaborative commerce has been used for communication, design, planning, information sharing, and information discovery in business-to-business (B2B) applications. The collaboration between buyers and sellers enhance...
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Collaborative commerce has been used for communication, design, planning, information sharing, and information discovery in business-to-business (B2B) applications. The collaboration between buyers and sellers enhances product quality and customer satisfaction. However, most effort currently focuses on information sharing with customers and suppliers instead of joint product development or manufacturing. Moreover, traditional analytical methods have limited capability in solving problems. This study presents a framework for doing reverse simulation, where designers can reuse past experiments and change system parameters in manufacturing system for collaborative commerce. The framework integrates the object-oriented simulator and the object-oriented database. In this framework, the object-oriented database records the whole experiment scenarios and allows multiple planners with different expertise to involve concurrently and collaboratively. Then, simulations of advanced planning and scheduling in a product manufacturing environment that involves several planners working collaboratively are used for demonstration.
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...
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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 objectdatabase, 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. (c) 2007 Elsevier Ltd. All rights reserved.
Knowledge intensive applications require an intelligent environment, which can perform deductions in response to user queries or events that occur inside or outside of the applications. For that, we propose a fuzzy ac...
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Knowledge intensive applications require an intelligent environment, which can perform deductions in response to user queries or events that occur inside or outside of the applications. For that, we propose a fuzzy active object-oriented database for modeling knowledge intensive applications. In that, we incorporate fuzziness within the event, condition and action parts of an active rule. We consider deductive rules as special cases of active rules so that deductive queries are handled using abstract kind of events. We also introduce a model for fuzzy inferencing of fuzzy active rules where we develop a model for scenario concept. We use a Fuzzy Petri Net model for fuzzy rule-based inference.
Modeling spatiotemporal data, in particular fuzzy and complex spatial objects representing geographic entities and relations, is a topic of great importance ill geographic information systems, computer vision, environ...
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Modeling spatiotemporal data, in particular fuzzy and complex spatial objects representing geographic entities and relations, is a topic of great importance ill geographic information systems, computer vision, environmental data management systems, etc. Because of complex requirements, it is challenging to represent spatiotemporal data and its features in databases and to effectively query them. This article presents a new approach to model and query the spatiotemporal data of fuzzy spatial and complex objects and/or spatial relations. In our case study, we use a meteorological database application in an intelligent database architecture, which combines an object-oriented database with a knowledgebase for modeling and querying spatiotemporal objects. (c) 2008 Elsevier Inc. All rights reserved.
A query is said to be secure against inference attacks by a user if there exists no database instance for which the user can infer the result of the query, using only authorized queries to the user. In this paper, fir...
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A query is said to be secure against inference attacks by a user if there exists no database instance for which the user can infer the result of the query, using only authorized queries to the user. In this paper, first, the security problem against inference attacks on object-oriented databases is formalized. The definition of inference attacks is based on equational logic. Secondly, the security problem is shown to be undecidable, and a decidable sufficient condition for a given query to be secure under a given schema is proposed. The idea of the sufficient condition is to over-estimate inference attacks using over-estimated results of static type inference. The third contribution is to propose subclasses of schemas and queries for which the security problem becomes decidable. Lastly, the decidability of the security problem is shown to be incomparable with the static type inferability, although the tightness of the over-estimation of the inference attacks is affected in a large degree by that of the static type inference. (c) 2007 Elsevier Inc. All rights reserved.
A search condition in object-oriented/object-relational queries consists of nested predicates, which are predicates on path expressions. In this paper, we propose a new technique for estimating selectivity for nested ...
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A search condition in object-oriented/object-relational queries consists of nested predicates, which are predicates on path expressions. In this paper, we propose a new technique for estimating selectivity for nested predicates. Selectivity of a nested predicate, nested selectivity, is defined as the ratio of the number of the qualified objects of the starting class in the path expression to the total number of objects of the class. The new technique takes into account the effects of direct representation of the many-to-many relationship and the partial participation of objects in the relationship. These two features occur frequently in object-oriented/object-relational databases, but have not been properly handled in the conventional selectivity estimation techniques. For the many-to-many relationship, we generalize the block-hit function proposed by S.B. Yao to allow the cases that an object belongs to more than one block. For the partial participation, we propose the concept of active objects and extend our technique for total participation to handle active objects. We also propose efficient methods for obtaining statistical information needed for our estimation technique. We finally analyze the accuracy of our technique through a series of experiments and compare with the conventional ones. The experiment results showed that there was a significant inaccuracy in the estimation by the conventional ones, confirming the advantage of our technique. (c) 2006 Elsevier B.V. All rights reserved.
The SP theory of computing and cognition, described in previous publications, is an attractive model for intelligent databases because it provides a simple but versatile format for different kinds of knowledge, it has...
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The SP theory of computing and cognition, described in previous publications, is an attractive model for intelligent databases because it provides a simple but versatile format for different kinds of knowledge, it has capabilities in artificial intelligence, it can function effectively in the face of errors in its input data, and it can function like established database models when that is required. This paper first describes the SP theory in outline and the computer models in which it is expressed. The main sections of the paper describe, with examples from the SP62 computer model, how the SP framework can emulate other abstract models used in database applications: the relational model (including retrieval of information in the manner of query-byexample, creating a join between two or more tables, and aggregation), object-oriented models (including class-inclusion hierarchies, part-whole hierarchies and their integration, inheritance of attributes, cross-classification and multiple inheritance), and hierarchical and network models (including discrimination networks). Comparisons are made between the SP model and those other models. The artificial intelligence capabilities of the SP model are briefly reviewed: representation and integration of diverse kinds of knowledge in one versatile format;fuzzy pattern recognition and recognition at multiple levels of abstraction;best-match and semantic forms of information retrieval;various kinds of exact reasoning and probabilistic reasoning;analysis and production of natural language;planning;problem solving;and unsupervised learning. Also considered are ways in which current prototypes may be translated into an 'industrial strength' working system. (c) 2006 Elsevier B.V. All rights reserved.
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