- Email: [email protected]
Scheduling and recovering from perturbations in a flexible manufacturing system
IBM XT configuration having DOS3 operating system, at least 640 Kbyte memory, 10M Winchester and one floppy disc. 'She' helps to design multilevel apartment houses, 'she' designs, stores and draws apartment variants and aims to contribute to the architectural design Of complete dwelling houses.
EXIST - AN EXPERT SYSTEM FOR THE I N N E R P L A N T P L A N N I N G O F LOCATIONS Matthias Kloth and Bernd Hellingrath
Fraunhofer lnstitut fiir Transporttechnik und Warendistribution, Dortmund, West Germany The advantages of an object orientated representation are especially used for the modelling and preparation of objects within a layout. Layout components worked out by EXIST are presented in a classifying hierarchy, in order to come up to related characteristics of the objects. With the help of this classifying hierarchy it gets easy to describe the special and common characteristics of objects concerned. S C H E D U L I N G AND RECOVERING F R O M PERTURBATIONS IN A FLEXIBLE M A N U F A C T U R I N G SYSTEM Bernard Sauve
Research center of Compaonie G~nbrale d'Electricitb, Computer Science Dirision, Marcoussis, France The use of artificial intelligence techniques has been investigated for contributing to a solution
of the following problems: Daily predictive Scheduling in a flexible manufacturing system, and Real time control of production perturbations. The Laboratoires de Marcoussis have been working since 1984 on a daily workshop scheduling subject. This work has resulted in a prototype system, named SOJA, with several levels: Study of the shop capacity; Selection of the set of operations; Allocation of resources; Detailed scheduling; Real time recovering from perturbations. A main thrust of SOJA is to develop a general method for the representation of scheduling constraints. We are investigating the use of object oriented programming to represent all the relevant information of a scheduling problem, particularly information about the flexibility factors in a shop (machine alternatives, tool choices, storage location alternatives ...).
A KNOWLEDGE-BASED GRAPHICAL INTERFACE FOR STRUCTURAL DESIGN M. Balachandran and J. S. Gero
Department of Architectural Science, The University of Sydney, Australia In recent years, many efforts have been made in using artificial intelligence techniques for engineering applications. Knowledge-based systems technology provides means for the development of computer systems incorporating a variety of knowledge in a particular domain. It is highly desirable to develop a graphic input system which enables the computer to recognize what was intended by a
COMPUTATIONAL METHODS IN POTENTIAL AERODYNAMICS Editedby L. Morino,Professorof Aerospaceand MechanicalEngineering, Boston University
760 pagesprice $99 £66 (in the U.K. only) Published1986 ISBN0 905451376 0 93121506 4 (u.s., Canaeh,Mexico)
designer's sketch. The sketch might be input by drawing it directly on a tablet or by using icondriven techniques. Sketch recognition is the graphic equivalent of natural language interpretation. Designers express their thoughts, concepts and des.gin verbally and graphically. In a computer-aided design environment, a knowledge-based system should provide means to map between both sets of communication. In order to accomplish this, a semantic model must be constructed which is capable of recognizing the attributes and the whole description of objects and their relationships. In this paper we illustrate how knowledge engineering techniques can be used to aid in recognizing and diagnosing structural descriptions. Here we deal with basic structural entities such as beams, trusses and (structural) frames. The structural entities are grouped in a hierarchical form in which each entity is represented as a frame. The frame representation provides classification, inheritance, default, procedures and other types of knowledge organization. The important part of the system is the front-end interface. The system provides an icon-driven menu from which the designer can select the required options and sketch his or her design. The system interprets the design sketch and constructs a frame-based representation of the design. In recognizing the design description, the system attempts to classify the given description by matching against the model frames provided by the system. The system can identify the structural descriptions provided by the designer and infer various properties of that structural problem, for example, stability, redundancy, and so on.
The field of computational aerodynamics covers many areas in which methodologies are markedly different. This volume is based on a course held at Amalfi, Italy, which brought together widely recognised specialists using all these methods in order to compare and contrast different approaches. These include the integral-equation methods (boundary element or panel methods) for linear (subsonic and supersonic) flows, finite difference for non-linear transonic flows, and other methods for steady state, oscillatory and transient flows. Different approaches are also required in formulations for fixed and rotary wing formulations, and for analysis rather than design.
Contents Foundation of Potential Flows, STEADY SUBSONIC AND SUPERSONIC FLOWS: Review of the Historical Development of Surface Source Methods, Panel Methods: Pan Air, UNSTEADY SUBSONIC AND SUPERSONIC FLOWS: Unsteady Subsonic and Supersonic Flows - Historical Review, Basic Principles and Double Lattice Applications in Potential Aerodynamics, Comparison of Analysis Methods Used in Lifting Surface Theory, Introduction to the Green's Function Method in Aerodynamics, Mathematical Foundations of Integral-Equation Methods, STEADY TRANSONIC FLOWS: Transonic Potential Flow, Transonic Computational Design and Analysis Applications, Computational Procedures in Aerodynamic Design, Experience, Issues. and Opportunities in Steady Transonics, UNSTEADY TRANSONIC FLOWS: Unsteady Transonic Flow - Introduction. Current Trends, Applications, Finite Difference Methods for the Solution of Unsteady Potential Flows. An Integral Equation Method for Potential Aerodynamics, WAKE ANALYSIS: Steady and Unsteady Incompressible Free-Wake Analysis; Wake Dynamics for Incompressible and Compressible Flows. RECENT DEVELOPMENT: Some New Developments in Exact Integral Equation Formulations for Sub- or Transonic Compressible Potential Flow, An Integral Equation for Compressible Potential Flows in an Arbitrary Frame of Reference. ~
~l~l~licat~oz~
Orders to COMPUTATIONAL MECHANICS PUBLICATIONS, Ashurst Lodge, Ashurst, So.uthampton SO4~,/~C U;K. Tel: (042 129) 3223. Telex 47388 ATTN COMPMECH. Fax: (0703) 331020. For U.S.A., Cana_da an_a ~.ex~ .co: ~ l ~ , ~ ~,..,tot. a ~ L , MECHANIC S INC., 25 Bridge Street. BiUerica. MA 01821. U.S.A. Tel: .(617) 667-51J4t. _rA~- to. t .L.)o o ~ - ~ . ~ ;u,~. . . . . 196 COMPUTATIONAL MECHANICS INC., State 265, 17744 Skypark Ctrcle, Irvme, CA 92114, u.b.e,. "l'eL tl tq) ~o t ~ .
124
Artificial Intelligence in Engineering, 1987, Vol. 2, No. 2
EXIST - AN EXPERT SYSTEM FOR THE I N N E R P L A N T P L A N N I N G O F LOCATIONS Matthias Kloth and Bernd Hellingrath
Fraunhofer lnstitut fiir Transporttechnik und Warendistribution, Dortmund, West Germany The advantages of an object orientated representation are especially used for the modelling and preparation of objects within a layout. Layout components worked out by EXIST are presented in a classifying hierarchy, in order to come up to related characteristics of the objects. With the help of this classifying hierarchy it gets easy to describe the special and common characteristics of objects concerned. S C H E D U L I N G AND RECOVERING F R O M PERTURBATIONS IN A FLEXIBLE M A N U F A C T U R I N G SYSTEM Bernard Sauve
Research center of Compaonie G~nbrale d'Electricitb, Computer Science Dirision, Marcoussis, France The use of artificial intelligence techniques has been investigated for contributing to a solution
of the following problems: Daily predictive Scheduling in a flexible manufacturing system, and Real time control of production perturbations. The Laboratoires de Marcoussis have been working since 1984 on a daily workshop scheduling subject. This work has resulted in a prototype system, named SOJA, with several levels: Study of the shop capacity; Selection of the set of operations; Allocation of resources; Detailed scheduling; Real time recovering from perturbations. A main thrust of SOJA is to develop a general method for the representation of scheduling constraints. We are investigating the use of object oriented programming to represent all the relevant information of a scheduling problem, particularly information about the flexibility factors in a shop (machine alternatives, tool choices, storage location alternatives ...).
A KNOWLEDGE-BASED GRAPHICAL INTERFACE FOR STRUCTURAL DESIGN M. Balachandran and J. S. Gero
Department of Architectural Science, The University of Sydney, Australia In recent years, many efforts have been made in using artificial intelligence techniques for engineering applications. Knowledge-based systems technology provides means for the development of computer systems incorporating a variety of knowledge in a particular domain. It is highly desirable to develop a graphic input system which enables the computer to recognize what was intended by a
COMPUTATIONAL METHODS IN POTENTIAL AERODYNAMICS Editedby L. Morino,Professorof Aerospaceand MechanicalEngineering, Boston University
760 pagesprice $99 £66 (in the U.K. only) Published1986 ISBN0 905451376 0 93121506 4 (u.s., Canaeh,Mexico)
designer's sketch. The sketch might be input by drawing it directly on a tablet or by using icondriven techniques. Sketch recognition is the graphic equivalent of natural language interpretation. Designers express their thoughts, concepts and des.gin verbally and graphically. In a computer-aided design environment, a knowledge-based system should provide means to map between both sets of communication. In order to accomplish this, a semantic model must be constructed which is capable of recognizing the attributes and the whole description of objects and their relationships. In this paper we illustrate how knowledge engineering techniques can be used to aid in recognizing and diagnosing structural descriptions. Here we deal with basic structural entities such as beams, trusses and (structural) frames. The structural entities are grouped in a hierarchical form in which each entity is represented as a frame. The frame representation provides classification, inheritance, default, procedures and other types of knowledge organization. The important part of the system is the front-end interface. The system provides an icon-driven menu from which the designer can select the required options and sketch his or her design. The system interprets the design sketch and constructs a frame-based representation of the design. In recognizing the design description, the system attempts to classify the given description by matching against the model frames provided by the system. The system can identify the structural descriptions provided by the designer and infer various properties of that structural problem, for example, stability, redundancy, and so on.
The field of computational aerodynamics covers many areas in which methodologies are markedly different. This volume is based on a course held at Amalfi, Italy, which brought together widely recognised specialists using all these methods in order to compare and contrast different approaches. These include the integral-equation methods (boundary element or panel methods) for linear (subsonic and supersonic) flows, finite difference for non-linear transonic flows, and other methods for steady state, oscillatory and transient flows. Different approaches are also required in formulations for fixed and rotary wing formulations, and for analysis rather than design.
Contents Foundation of Potential Flows, STEADY SUBSONIC AND SUPERSONIC FLOWS: Review of the Historical Development of Surface Source Methods, Panel Methods: Pan Air, UNSTEADY SUBSONIC AND SUPERSONIC FLOWS: Unsteady Subsonic and Supersonic Flows - Historical Review, Basic Principles and Double Lattice Applications in Potential Aerodynamics, Comparison of Analysis Methods Used in Lifting Surface Theory, Introduction to the Green's Function Method in Aerodynamics, Mathematical Foundations of Integral-Equation Methods, STEADY TRANSONIC FLOWS: Transonic Potential Flow, Transonic Computational Design and Analysis Applications, Computational Procedures in Aerodynamic Design, Experience, Issues. and Opportunities in Steady Transonics, UNSTEADY TRANSONIC FLOWS: Unsteady Transonic Flow - Introduction. Current Trends, Applications, Finite Difference Methods for the Solution of Unsteady Potential Flows. An Integral Equation Method for Potential Aerodynamics, WAKE ANALYSIS: Steady and Unsteady Incompressible Free-Wake Analysis; Wake Dynamics for Incompressible and Compressible Flows. RECENT DEVELOPMENT: Some New Developments in Exact Integral Equation Formulations for Sub- or Transonic Compressible Potential Flow, An Integral Equation for Compressible Potential Flows in an Arbitrary Frame of Reference. ~
~l~l~licat~oz~
Orders to COMPUTATIONAL MECHANICS PUBLICATIONS, Ashurst Lodge, Ashurst, So.uthampton SO4~,/~C U;K. Tel: (042 129) 3223. Telex 47388 ATTN COMPMECH. Fax: (0703) 331020. For U.S.A., Cana_da an_a ~.ex~ .co: ~ l ~ , ~ ~,..,tot. a ~ L , MECHANIC S INC., 25 Bridge Street. BiUerica. MA 01821. U.S.A. Tel: .(617) 667-51J4t. _rA~- to. t .L.)o o ~ - ~ . ~ ;u,~. . . . . 196 COMPUTATIONAL MECHANICS INC., State 265, 17744 Skypark Ctrcle, Irvme, CA 92114, u.b.e,. "l'eL tl tq) ~o t ~ .
124
Artificial Intelligence in Engineering, 1987, Vol. 2, No. 2