An object oriented data modelling in computer aided design (CAD) databases is focused. Starting with the discussion of data modelling requirements for CAD applications, appropriate data modelling features are introdu...An object oriented data modelling in computer aided design (CAD) databases is focused. Starting with the discussion of data modelling requirements for CAD applications, appropriate data modelling features are introduced herewith. A feasible approach to select the “best” data model for an application is to analyze the data which has to be stored in the database. A data model is appropriate for modelling a given task if the information of the application environment can be easily mapped to the data model. Thus, the involved data are analyzed and then object oriented data model appropriate for CAD applications are derived. Based on the reviewed object oriented techniques applied in CAD, object oriented data modelling in CAD is addressed in details. At last 3D geometrical data models and implementation of their data model using the object oriented method are presented.展开更多
A Model, called 'Entity-Roles' is proposed in this paper in which the world of Interest is viewed as some mathematical structure. With respect to this structure, a First order (three-valued) Logic Language is ...A Model, called 'Entity-Roles' is proposed in this paper in which the world of Interest is viewed as some mathematical structure. With respect to this structure, a First order (three-valued) Logic Language is constructured.Any world to be modelled can be logically specified in this Language. The integrity constraints on the database and the deducing rules within the Database world are derived from the proper axioms of the world being modelled.展开更多
This paper describes multi view modeling and data model transformation for the modeling. We have proposed a reference model of CAD system generation, which can be applied to various domain specific languages. Howeve...This paper describes multi view modeling and data model transformation for the modeling. We have proposed a reference model of CAD system generation, which can be applied to various domain specific languages. However, the current CAD system generation cannot integrate data of multiple domains. Generally each domain has its own view of products. For example, in the domain of architectural structure, designers extract the necessary data from the data in architecture design. Domain experts translate one view into another view beyond domains using their own brains.The multi view modeling is a way to integrate product data of multiple domains, and make it possible to translate views among various domains by computers.展开更多
The current GIS can only deal with 2-D or 2.5-D information on the earth surface. A new 3-D data structure and data model need to be designed for the 3-D GIS. This paper analyzes diverse 3-D spatial phenomena from min...The current GIS can only deal with 2-D or 2.5-D information on the earth surface. A new 3-D data structure and data model need to be designed for the 3-D GIS. This paper analyzes diverse 3-D spatial phenomena from mine to geology and their complicated relations, and proposes several new kinds of spatial objects including cross-section, column body and digital surface model to represent some special spatial phenomena like tunnels and irregular surfaces of an ore body. An integrated data structure including vector, raster and object-oriented data models is used to represent various 3-D spatial objects and their relations. The integrated data structure and object-oriented data model can be used as bases to design and realize a 3-D geographic information system.展开更多
Modeling plays an important role for the solution of the complex research problems. When the database became large and complex then it is necessary to create a unified model for getting the desired information in the ...Modeling plays an important role for the solution of the complex research problems. When the database became large and complex then it is necessary to create a unified model for getting the desired information in the minimum time and to implement the model in a better way. The present paper deals with the modeling for searching of the desired information from a large database by storing the data inside the three dimensional data cubes. A sample case study is considered as a real data related to the ground water and municipal water supply, which contains the data from the various localities of a city. For the demonstration purpose, a sample size is taken as nine but when it becomes very large for number of localities of different cities then it is necessary to store the data inside data cubes. A well known object-oriented Unified Modeling Language (UML) is used to create Unified class and state models. For verification purpose, sample queries are also performed and corresponding results are depicted.展开更多
In this paper, an open architecture and its implementation for product data management are presented. The system architecture, product data definition model, and a set of components of the architecture are discussed i...In this paper, an open architecture and its implementation for product data management are presented. The system architecture, product data definition model, and a set of components of the architecture are discussed in detail. Especially, the principle and some mechanism of one of the components, an object oriented database management system GH-EODB, are discussed in more detail. The architecture is extensible and adaptable.展开更多
With respect to the mathematical structure supposed by theEntity-Roles Model. a first order (three--valued) logic language is constructured. A world to be modelled can be logically specified in this language. The inte...With respect to the mathematical structure supposed by theEntity-Roles Model. a first order (three--valued) logic language is constructured. A world to be modelled can be logically specified in this language. The integrity constraints on the database and展开更多
In object-oriented database systems(OODBSs),the traditional transaction models are no longer suit- able because of the difference between the object-oriented data model(OODM)and the conventional da- ta models(e.g.rela...In object-oriented database systems(OODBSs),the traditional transaction models are no longer suit- able because of the difference between the object-oriented data model(OODM)and the conventional da- ta models(e.g.relational data model).In this paper,transaction models for advanced databuse applica- tions are reviewed and their shortcomings are analyzed.Exchangeability of operations is proposed in- stead of commuativity and recoverability for using more semantics in transaction management.As a result,an object-oriented transaction model(in short,OOTM)is presented.It is not modeled for some special application,but directly based on object-oriented paradigms.A transaction is regarded as an interpretation of a method.Each transaction(even subtransactions)keeps relative ACID(Atomicity, Consistency,Isolation,Durability )properties,therefore the special problems appearing in OODBSs such as“long transactions”,“visibility of inconsistent database state”can be solved.展开更多
Powerful expressive ability of semantic information, to be easily computed and flexibility are basic features of digital product model (DPM). Using ontology and object-oriented principle (OOP) together to cope with pr...Powerful expressive ability of semantic information, to be easily computed and flexibility are basic features of digital product model (DPM). Using ontology and object-oriented principle (OOP) together to cope with problems in modeling is brought forward in this paper. The two are widely used and do well in modeling, but they each alone cannot cope with all issues and new challenges. Three basic requests are pointed out in DPM modeling. Status, problems, and root of current non-semantic and semantic models are introduced. Ontology, OOP, and their difference are introduced. It is found that the two are entirely complementary with each other. How to assign the roles and to cooperate for the two in coping with the three basic issues in DPM modeling are explained in detail.展开更多
文摘An object oriented data modelling in computer aided design (CAD) databases is focused. Starting with the discussion of data modelling requirements for CAD applications, appropriate data modelling features are introduced herewith. A feasible approach to select the “best” data model for an application is to analyze the data which has to be stored in the database. A data model is appropriate for modelling a given task if the information of the application environment can be easily mapped to the data model. Thus, the involved data are analyzed and then object oriented data model appropriate for CAD applications are derived. Based on the reviewed object oriented techniques applied in CAD, object oriented data modelling in CAD is addressed in details. At last 3D geometrical data models and implementation of their data model using the object oriented method are presented.
文摘A Model, called 'Entity-Roles' is proposed in this paper in which the world of Interest is viewed as some mathematical structure. With respect to this structure, a First order (three-valued) Logic Language is constructured.Any world to be modelled can be logically specified in this Language. The integrity constraints on the database and the deducing rules within the Database world are derived from the proper axioms of the world being modelled.
文摘This paper describes multi view modeling and data model transformation for the modeling. We have proposed a reference model of CAD system generation, which can be applied to various domain specific languages. However, the current CAD system generation cannot integrate data of multiple domains. Generally each domain has its own view of products. For example, in the domain of architectural structure, designers extract the necessary data from the data in architecture design. Domain experts translate one view into another view beyond domains using their own brains.The multi view modeling is a way to integrate product data of multiple domains, and make it possible to translate views among various domains by computers.
基金Project supported by the National Natural Science Foundation of China (No.49871066)
文摘The current GIS can only deal with 2-D or 2.5-D information on the earth surface. A new 3-D data structure and data model need to be designed for the 3-D GIS. This paper analyzes diverse 3-D spatial phenomena from mine to geology and their complicated relations, and proposes several new kinds of spatial objects including cross-section, column body and digital surface model to represent some special spatial phenomena like tunnels and irregular surfaces of an ore body. An integrated data structure including vector, raster and object-oriented data models is used to represent various 3-D spatial objects and their relations. The integrated data structure and object-oriented data model can be used as bases to design and realize a 3-D geographic information system.
文摘Modeling plays an important role for the solution of the complex research problems. When the database became large and complex then it is necessary to create a unified model for getting the desired information in the minimum time and to implement the model in a better way. The present paper deals with the modeling for searching of the desired information from a large database by storing the data inside the three dimensional data cubes. A sample case study is considered as a real data related to the ground water and municipal water supply, which contains the data from the various localities of a city. For the demonstration purpose, a sample size is taken as nine but when it becomes very large for number of localities of different cities then it is necessary to store the data inside data cubes. A well known object-oriented Unified Modeling Language (UML) is used to create Unified class and state models. For verification purpose, sample queries are also performed and corresponding results are depicted.
基金the High Technoloey Research and Development Programme of China
文摘In this paper, an open architecture and its implementation for product data management are presented. The system architecture, product data definition model, and a set of components of the architecture are discussed in detail. Especially, the principle and some mechanism of one of the components, an object oriented database management system GH-EODB, are discussed in more detail. The architecture is extensible and adaptable.
文摘With respect to the mathematical structure supposed by theEntity-Roles Model. a first order (three--valued) logic language is constructured. A world to be modelled can be logically specified in this language. The integrity constraints on the database and
文摘In object-oriented database systems(OODBSs),the traditional transaction models are no longer suit- able because of the difference between the object-oriented data model(OODM)and the conventional da- ta models(e.g.relational data model).In this paper,transaction models for advanced databuse applica- tions are reviewed and their shortcomings are analyzed.Exchangeability of operations is proposed in- stead of commuativity and recoverability for using more semantics in transaction management.As a result,an object-oriented transaction model(in short,OOTM)is presented.It is not modeled for some special application,but directly based on object-oriented paradigms.A transaction is regarded as an interpretation of a method.Each transaction(even subtransactions)keeps relative ACID(Atomicity, Consistency,Isolation,Durability )properties,therefore the special problems appearing in OODBSs such as“long transactions”,“visibility of inconsistent database state”can be solved.
基金Supported by the Ministries’ Basic Research Foundation, China Knowledge Engineering Platform for Enterprise Innovative Design(No. B0920060901)
文摘Powerful expressive ability of semantic information, to be easily computed and flexibility are basic features of digital product model (DPM). Using ontology and object-oriented principle (OOP) together to cope with problems in modeling is brought forward in this paper. The two are widely used and do well in modeling, but they each alone cannot cope with all issues and new challenges. Three basic requests are pointed out in DPM modeling. Status, problems, and root of current non-semantic and semantic models are introduced. Ontology, OOP, and their difference are introduced. It is found that the two are entirely complementary with each other. How to assign the roles and to cooperate for the two in coping with the three basic issues in DPM modeling are explained in detail.
