The control of batch manufacturing systems is complex, and one viable solution is to break control into a series of levels within an overall hierarchy of control. Cell control forms a major element of such a hierarchy...
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The control of batch manufacturing systems is complex, and one viable solution is to break control into a series of levels within an overall hierarchy of control. Cell control forms a major element of such a hierarchy in that cell controllers manage and co-ordinate the manufacturing equipment within each cell. This equipment includes robots, machine tools and material handling systems. This paper reviews objectorientedprogramming, and describes its use in a cell control system termed X-Cell. object-oriented programming has advantages in terms of a modular programming style, an increased flexibility and easier maintainability. An overview of X-Cell is given. Three main modules are used: the scheduler, the operation dispatcher, and the monitor. Each uses a number of objects. The use of object-oriented programming results in flexibility in handling a wide range of factors.
A block diagram editor has been developed for the Macintosh personal computer from a specification developed for a general graphical human-computer interface for an extended X-based Control Engineering workstation (eX...
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A block diagram editor has been developed for the Macintosh personal computer from a specification developed for a general graphical human-computer interface for an extended X-based Control Engineering workstation (eXCeS). It was implemented using THINK C. a version of C with object-oriented extensions that has been specially developed to provide case of programming for graphics based applications in the Macintosh environment. Our experiences are reported on using this programming environment for this application and details are given of its design and implementation. We also comment on the applicability of the objectoriented paradigm for the development of Computer-Aided Control Systems Design (CACSD) tools.
Traditional scheduling tools for continuous process industries have not been developed with batch processing in mind. Efficient batch processing requires intelligent scheduling tools. The principal contribution of thi...
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Traditional scheduling tools for continuous process industries have not been developed with batch processing in mind. Efficient batch processing requires intelligent scheduling tools. The principal contribution of this research is the development of an architecture which combines intelligent tools with a virtual plant for performing management tasks. One of the intelligent tools, a flexible scheduling algorithm based on object-oriented constructs to schedule batch processes, is presented. A virtual plant is used to map chemical processes with equipment in the plant. The scheduling algorithm then uses a database of current customer orders and a knowledge base that contains rules about customer priority, equipment cleaning, process preference, equipment history, batch sequencing rules, cost history, cost estimates, and other knowledge to aid the user in the selection of the appropriate schedule. The uniqueness of this approach is the integration of a virtual plant, which can be viewed as a static plant simulation model, with a rule-based scheduling approach.
This paper describes the object-oriented implementation of a number of low-level image processing algorithms on the Intel iPSC/2 hypercube multicomputer. They include noise reduction using local averaging, edge detect...
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This paper describes the object-oriented implementation of a number of low-level image processing algorithms on the Intel iPSC/2 hypercube multicomputer. They include noise reduction using local averaging, edge detection using the Sobel operator, image thinning and line detection using the Hough transform. The objective is to parallelize these algorithms using the object-oriented language C++, and to measure the speedup using 2, 4, 8, 16 and 32 processors vs using 1 processor. Also, the speedup is found for performing all of the algorithms in a row, vs separately. A 512 x 512 binary image is processed, and a maximum speedup of 5.88 is found when performing all of the algorithms in a row, including communication of the input data file from the host, and the results from the nodes to the host. The speedup for processing when including only interprocessor communication is 17.25. The reasons behind the speedups are discussed, as well as suggestions to obtain better performance.
In this paper we present a new concept of FE modeling, based on the object-oriented principle, and develop the prototype progam MODIFY (MODeling tool for Integrated Finite element analysis). MODIFY has three novel fea...
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In this paper we present a new concept of FE modeling, based on the object-oriented principle, and develop the prototype progam MODIFY (MODeling tool for Integrated Finite element analysis). MODIFY has three novel features: (1) FE modeling by the part object concept, (2) a fully object-oriented data structure, and (3) a part-by-part Sully automated mesh subdivision. When using MODIFY it is necessary to define and assemble part objects, which consist of geometry objects, analytical condition objects and relation objects, to describe the continuity between adjacent part objects. MODIFY automatically generates an appropriate FE model for each geometry object, satisfying continuity conditions with adjacent parts by referring to relation objects. If some part of the model is to be modified, the user needs only to change the corresponding part objects. Because of the object-oriented data structure, MODIFY also has a powerful capability for adaptive meshing. The existing version of MODIFY is applicable to FE models for 3-D shell structures.
We have developed and implemented a computer-based method to generate and enumerate all conjugate forms of acyclic organic compounds. These algorithms are used in a new approach for the estimation of thermodynamic and...
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We have developed and implemented a computer-based method to generate and enumerate all conjugate forms of acyclic organic compounds. These algorithms are used in a new approach for the estimation of thermodynamic and physical properties of acyclic organic compounds from their molecular structure. The approach is based on the contributions of Atoms and Bonds in the properties of Conjugate forms (ABC) of a compound and has produced more accurate results than group-contribution methods. Generating all conjugate forms of the molecule whose properties we wish to estimate is necessary in the application of this technique. The use of symbolic computing environments allows the flexible representation and manipulation of molecular structures. Atoms, bonds, molecules, and other entities are represented as interconnected objects. The generation, comparison, and analysis of conjugates are carried out through computer-based manipulation of the objects and their interconnections.
The methodology for developing intelligent integrated computer-aided design and manufacturing systems based on object-oriented principles is discussed. The ways in which the application of these principles affects the...
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The methodology for developing intelligent integrated computer-aided design and manufacturing systems based on object-oriented principles is discussed. The ways in which the application of these principles affects the nature of these systems are reviewed. The implementation of an automated, intelligent, and flexible computer-integrated-manufacturing (CIM) system prototype using an object-oriented programming environment (Smalltalk-80, Version 4.0) is detailed. A CIM system includes CAD, a process planner, and an inspection planner. Each of these components is discussed individually
This paper presents an object-oriented interface for parallel programming, and an algorithm for automatic translation into parallel programs. The programming interface consists of a restricted subset of the object-ori...
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This paper presents an object-oriented interface for parallel programming, and an algorithm for automatic translation into parallel programs. The programming interface consists of a restricted subset of the object-oriented language C++. Parallelism is defined explicitly at the abstract level of object definitions and method invocations within a single C++ program. The translator algorithm first generates a machine-independent communication graph and proceeds with the creation of the parallel programs, which are demonstrated for transputer systems with the HELIOS operating system. The necessary communication statements are generated automatically.
We present our experience withEuLisp as a teaching language, focussing on the level of the language which was specifically designed for this purpose (level-0).EuLisp has been used in undergraduate and postgraduate tea...
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We present our experience withEuLisp as a teaching language, focussing on the level of the language which was specifically designed for this purpose (level-0).EuLisp has been used in undergraduate and postgraduate teaching since 1990, in lectures and laboratories, where in many cases it has replaced Scheme or Common Lisp. It has been used extensively in programming courses, parallelism courses, as a vehicle for advanced courses in symbolic computing and programming language design; it has also been used as a platform for final year undergraduate projects. This experience has demonstrated thatEuLisp is well suited to teaching and far reaching in its capabilities: it supports the relevant concepts in a consistent and versatile framework, so that the language serves to facilitate the educational process. The discussion is illustrated with examples, and where appropriate we draw a comparison with the Lisp dialects used previously in these courses.
Writing portable applications for MIMD (multiple-instruction, multiple-data) architectures has proven to be more difficult than writing sequential software. This is due in large part to the lack of easy-to-use, high-l...
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Writing portable applications for MIMD (multiple-instruction, multiple-data) architectures has proven to be more difficult than writing sequential software. This is due in large part to the lack of easy-to-use, high-level abstractions. Mentat is an object-oriented parallel processing system designed to directly address the difficulty of developing architecture-independent parallel programs. Its fundamental objectives are to provide easy-to-use parallelism, achieve high performance via parallel execution, and facilitate the portability of applications across a wide range of platforms. The premise underlying Mentat is that it is the lack of appropriate abstractions that has kept parallel architectures difficult to program and hence made them inaccessible to mainstream, production system programmers. The Mentat approach combines a medium-grain, data-driven computation model with the object-oriented programming paradigm. The data-driven computation model supports high degrees of parallelism, while the use of the object-oriented paradigm permits hiding much of the parallel environment from the programmer. The Mentat system consists of two components, the Mentat programming Language (MPL) and the Mentat runtime system. The MPL is an object-oriented programming language based on C++. The programmer is responsible for identifying those classes, called Mentat classes, whose member functions are of sufficient computational complexity to allow efficient parallel execution. Instances of Mentat classes are used like C++ classes. The data and control dependencies between Mentat class instances involved in invocation, communication, and synchronization are detected and managed by the compiler and runtime system without programmer intervention. Mentat is available via anonymous FTP and has been implemented on Sun workstations, the Silicon Graphics Iris, the Intel iPSC/2, and the Intel iPSC/860. This article presents the Mentat programming language, including several examples, the M
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