In this paper we present an approach to integrating optimisation tools with simulation software to achieve user-defined objectives. A formal protocol is presented, including specific definitions of the requirements of...
详细信息
In this paper we present an approach to integrating optimisation tools with simulation software to achieve user-defined objectives. A formal protocol is presented, including specific definitions of the requirements of the simulator, optimiser, and design interface. A discussion of the mathematical issues and the efficiency of different approaches for computing sensitivities is given. We then discuss the source code modifications necessary to accomplish the integration of simulation and optimisation. (C) 1996 by Elsevier Science Inc.
Test data are an invaluable resource for structural engineering research. In this paper, a numerical database system is built for material properties of steels, steel columns, steel beams and unstiffened steel plates,...
详细信息
Test data are an invaluable resource for structural engineering research. In this paper, a numerical database system is built for material properties of steels, steel columns, steel beams and unstiffened steel plates, etc. The database is used to clarify the strength variations of material properties and to obtain the mean value and the coefficient of variation of each member strength. In addition, these values are compared with existing design formulas. The database is further developed in the shape of a structural test information-based system. This system includes database functions, test data evaluation functions, reference retrieval functions and technical terms explanation functions. The usefulness of the knowledge base approach for representing the test data is proved and the potential and problems of the system are clarified. Copyright (C) 1996 Elsevier Science Ltd.
The efficiency of object-oriented programs has become a point of great interest, One necessary factor for program efficiency is the optimization techniques involved. This paper presents the performance of several vari...
详细信息
The efficiency of object-oriented programs has become a point of great interest, One necessary factor for program efficiency is the optimization techniques involved. This paper presents the performance of several variations of a given C++ program and compares them with a version that uses no object-oriented features, Our result indicates that some object-oriented features in C++ are not well optimized in current C++ compilers. We thus discuss some code optimization techniques that can improve the efficiency based on the given C++ program.
DESC++ (Discrete Event Simulation package using C++) has been developed as an object-oriented tool for quantitative simulation studies of communication protocols and architectures of telecommunication networks. The ma...
详细信息
DESC++ (Discrete Event Simulation package using C++) has been developed as an object-oriented tool for quantitative simulation studies of communication protocols and architectures of telecommunication networks. The main issue of such performance studies is to secure proper statistical accuracy of the final simulation results. In DESC++ this problem has been solved by automating analysis of simulation output data, aimed at stopping simulation when the estimates reach the required level of precision. The package consists of various object classes. While some of them are responsible for on-line output data analysis, others allow simulation programs of telecommunication networks to be easily developed by re-using existing (sub)models. We discuss main design and implementational issues of DESC++, and illustrate them by an example. Copyright (C) 1996 Elsevier Science Ltd
An object-oriented data model for the elaboration of scanning probe microscopy information is proposed. This data model provides a comfortable interoperability between different types of data, presented as visual obje...
详细信息
An object-oriented data model for the elaboration of scanning probe microscopy information is proposed. This data model provides a comfortable interoperability between different types of data, presented as visual objects. On the other hand, this model correlates with modern compound document programming technology, and can be implemented within a client-server application, exploiting the benefits of distributed data systems. Such a data model is suitable for scanning probe microscopy image processing, and could be useful for some other research fields, allowing the integration of a huge amount of composite data.
One of the most intriguing-and at the same time most problematic-notions in object-oriented programming is inheritance. Inheritance is commonly regarded as the feature that distinguishes object-oriented programming fr...
详细信息
One of the most intriguing-and at the same time most problematic-notions in object-oriented programming is inheritance. Inheritance is commonly regarded as the feature that distinguishes object-oriented programming from other modern programming paradigms, but researchers rarely agree on its meaning and usage. Yet inheritance is often hailed as a solution to many problems hampering software development, and many of the alleged benefits of object-oriented programming, such as improved conceptual modeling and reusability, are largely credited to it. This article aims at a comprehensive understanding of inheritance, examining its usage, surveying its varieties, and presenting a simple taxonomy of mechanisms that can be seen as underlying different inheritance models.
An approach to the computer aided analysis of flexible multibody systems using object-oriented programming methods is presented. The aim is to support the rapid generation of specialized programs by providing an open,...
详细信息
An approach to the computer aided analysis of flexible multibody systems using object-oriented programming methods is presented. The aim is to support the rapid generation of specialized programs by providing an open, extensible C++ toolkit. This toolkit contains modules (C++ classes) which allow the declaration and manipulation of multibody components such as joints, bodies and actuators in an intuitive manner. New components (e.g., new finite elements) are easily introduced to extend the toolkit. The equations of motion for a multibody system consisting of these components are formulated by direct application of the principle of virtual work using symbolic techniques. It is possible to use absolute as well as relative coordinates in a problem-dependent manner.
In this paper, the bill of materials (BOM) system is defined as the central hub of a general product data management (PDM) system that provides essential data for running a manufacturing system to produce products. In...
详细信息
In this paper, the bill of materials (BOM) system is defined as the central hub of a general product data management (PDM) system that provides essential data for running a manufacturing system to produce products. Information that is relevant to products and their components is defined in the BOM. The information is critically related to data from product design, manufacturing planning, production management, procurement, inventory control, and accounting within a company. A conventional BOM structure (or product configuration), which manages data only in a stand-alone relational database management style, cannot satisfy the needs requested by all departments within a company. A BOM should relate to and communicate with other domains of the information system. In this research, a newly designed BOM system uses the object-oriented programming (OOP) concept to represent product information. The object-oriented BOM (OOBOM) system can capture and encapsulate data that will simultaneously serve the information needs of various departments. In order to manage product data dynamically, the system provides several interfaces for easy data access and manipulation. The linkage between BOM and its corresponding CAD/CAM system is enabled through the X-window manager: thus an integrated PDM environment is developed. This product management approach improves the consistency and efficiency of product data representation.
作者：
Thiery, RCREGU
BP 23 F-54501 Vandoeuvre-lès-Nancy Cedex France
A new global approach for calculating thermodynamic properties of fluids with equations of state is proposed. This method uses an object-oriented library, written in C++, and containing a number of routines that facil...
详细信息
A new global approach for calculating thermodynamic properties of fluids with equations of state is proposed. This method uses an object-oriented library, written in C++, and containing a number of routines that facilitate thermodynamic calculations. It is applicable to any equation of state formulated by an analytical expression of the Helmholtz free energy. The programming work of the user is limited to the building of a parse representation of the Helmholtz free energy. This parse graph is then processed by the program for analytically calculating the required derivatives and thermodynamic properties of fluids. A demonstration of this library is made with the Anderko and Fitter equation of state for H2O-NaCl-KCl fluids. The Helmholtz free energy has been differentiated analytically up to the fourth order with respect to the temperature, molar volume, and composition. Calculated derivatives are used to calculate the critical line of H2O-NaCl mixtures and other thermodynamic properties, which otherwise would be difficult to obtain. Copyright (C) 1996 Elsevier Science Ltd
As a response to the need for flexible manufacturing cells in high-technology industries, automated equipment has been developed in recent years, Also, factory-level integrated production control is belong developed i...
详细信息
As a response to the need for flexible manufacturing cells in high-technology industries, automated equipment has been developed in recent years, Also, factory-level integrated production control is belong developed in some industries using the potential of modern computer systems, A manufacturing cell is a group of automatic machines which must be controlled so as to behave as a single unit when viewed from the wider perspective. Cell-level control must be implemented to allow consistent automated operation of the cell and its efficient integration into the wider industrial process. Such a control system should provide high process and product flexibility, as well as high system maintainability. The general principles of automated cell control and robot control at the function and task Levels are therefore investigated in this paper, and the appropriate modelling and programming concepts analysed, A framework is developed which is appropriate for small, unmanned manufacturing cells comprising machine tools, robots and other automated equipment, both from the perspective of developing new software and extending, or re-engineering, existing software. The particular problems of using robots in such environments are also discussed, Copyright (C) 1996 Elsevier Science Ltd.
暂无评论