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EXLOG: An expert system for logic synthesis in full-custom VLSI design
RECOGNITION OF TEMPORAL P H E N O M E N A IN DRILLING Blaquiere ,Marc and Evrard Fain-ice
Total Research Center, 78470 - St. Remy les Cherreuses, France This paper is a presentation of an Expert System built to help understanding drilling situations by log analysis, and hence prevent risks. First we give some general remarks, then we go on to describe the main fundamentals on which the data processing system is based e.g.: agglutination, closed world assumption, nonmonotonic reasoning, real time inference mechanism, transient anomaly. Knowledge representation is based upon several networks: sensors, temporal constraints, states, rules and rules chaining networks. This knowledge is associated with learning methods and Interaction capabilities. SEMANTICALLY EXTENDED LOGIC P R O G R A M M I N G E N V I R O N M E N T FOR CAD/CAPP APPLICATIONS Vesselin I. Kirov
INTERPROGRAMA Software R & D Institute, Sofia, Bulgaria The tendency of unification, normalization and standardization of design solutions at lower levels and the schemes of their composition at higher levels, taking place in industry at present, serves as an ideal basis for computer-aided modular design. The modular design environment consists of functionally complete, usually redundant, set of parts and units (considered as primitives by convention), which could be combined and composed in different (but a priori determined) ways in order to produce potentially unlimited multiplicitly of regular structures on the basis of a relatively smaller number of functionally equivalent variant design solutions, the latter varying mainly in their structure and parameter values. In the paper a knowledge-representation/ problem-solving language, designed in accordance with the principles of conceptual modelling, is described. It has been developed with computer-aided design (CAD)/computeraided process planning (CAPP) problems in mind but it seems to be applicable to many others as well. The systhesis of an object structure that provides a necessary functionality is considered to be the main design problem, possesing many specific features and requiring a different approach in contrast to many other tasks. EXLOG: AN EXPERT SYSTEM FOR LOGIC SYNTHESIS IN FULL-CUSTOM VLSI DESIGN 3,1. Watanabe, 3'1. lwamoto, T. Yamanouchi, H. Matsuda and D. J. Littleboy
C&C Systems Research Laboratory, NEC Corporation. Kanagawa 213, Japan N. Maeda, 3,1. Kawarabayashi and M. Imahashi
VLSI CAD Engineerm9 Dicision, NEC Corporation This paper describes EXLOG, a knowledgebased CAD tool for logic synthesis in fullcustom VLSI design. EXLOG accepts as input a specification of a functional module of a VLSI circuit, written in Functional Description Language IFDL), and synthesizes from that specification a gate and switch level description in Gate Description Language {GDLL Since the EXLOG process closely follows that used by expert designers, it allows the use of expert knowledge in place of combinatoric search in the design process.
EXLOG is implemented in CNL, an expert systems tool which provides a wide variety of programming paradigms. For design problems of a functional module on the order of I000 gates, EXLOG has produced verified designs of similar size and quality to that of design experts.
LIFT-3: A KNOWLEDGE-BASED SYSTEM F O R P L A N N I N G INSTALLATION PROCESSES IN THE O F F S H O R E INDUSTRY A. Bremdal and S. Kristiansen
Division of Marine Systems Design, Department of Marine Technology, Norwegian Institute of Technology The paper will open by introducing the concept of marine operations and the role these operations play in the offshore related oil industry in the North Sea. As a special case, installation tasks will be discussed. Different engineering aspects related to this will be treated with respect to environment, design of the offshore systems and the planning task involved. Oil fields in the North Sea are characterized by a harsh environment and novel, complex units that support oil welldrilling, oil and gas production and transportation. Careful planning of installation tasks with regard to economy and safety is required. The problem is magnified by project management difficulties on field-development scale and in fitting operations within specific 'weather windows'. Some of the subtasks of these particular installation processes include selection and assignment of vessels and tools, mobilization planning, planning of vessel movements and vessel positions, installation sequences. In this context the existing computer aid will also be discussed briefly. To support the different views in this section some references will be made to field investigations and studies carried out within the oil industry.
K N O W L E D G E BASED STEAM PLANT OPERATION R. Fjellheim and T. Pettersen
Computas Expert Systems, Norway Steamex, the expert system described in this paper, is a support tool for operators of a large steam plant at a major chemical factory. In addition to the central steam generation facility (5 boilers, 180-250 tons/hour production), the plant comprises three separate distribution nets (operating at different steam pressure levels), and several hundred steam consumers. The main goal of the Steamex system is to give advice on improving fuel economy of the plant, but also to assist operators in assessing the system state and to rapidly diagnose causes for deviant behaviour of the steam boilers and distribution nets. Steamex is an open-loop system, i.e., provides advice to the operator, who then has to decide whether to follow the advice or not. The system is implemented in a modular fashion, with the main modules being state identification (including derivation of states not directly observable), situation assessment (translation of numerical to qualitative statements), and fuel optimization (based on fluctuating oil/electricity prices). In addition, there are modules for interfacing to the process (fuel consumption meters, steam pressure sensors, etc.) and to the operator through a graphical screen.
GEAREX: A UNIX BASED GEARBOX SELECTION EXPERT SYSTEM Gautam Bose and C. S. Krislmamoorthy
CAD~CAM Programme. Indian Institute of Technology, Madras-600 036, India This paper describes a 'Gearbox Selection Expert System" for general purpose industrial gearbox selection. Initially the nature of the problem is examined and the strategy adopted is explained. Then the type of knowledge representation is detailed. The key features of GEAREX are the use of objects, rules and a relational database management system (RDBMS) for representing the active and static knowledge bases. The system has been developed on a UNIX based minicomputer and implemented using "C" language.
EXPLANATORY K N O W L E D G E TOOLS FOR EXPERT SYSTEMS R. Dieng, O. Corby and P. Haren
INR1A, Centre de Sophia-Antipolis, 06565 Valbonne Cedex, France In this paper, we propose some idea in order to express general principles of the reasoning of an expert system and to provide userdepending explanations: filter reasoning trace and knowledge base according to user's model and detail level; define a class Explanation and describe, through a hierarchy of subclasses, different explanation levels; bind Explanation objects (instances of the class Explanation) to interesting objects for the user; use a mechanism of active values in order to trigger explanations at each modification of the objects to explain; build an explainer expert system, provided with explanation rules and observing the other expert system during or after reasoning. We show how those ideas can be implemented in SMECI shell (Cooperating Expert Systems for Civil Engineering Design): we use its knowledge representation (frames and rules divided in rulesets) and its reasoning mode (possibility for several expert systems to work at the same time). DIAGNOSIS USING CAUSAL DEPENDENCIES Vijay Baudekar
Siemens Coprorate Research, 8000 Munich 83, FRG Theories of qualitative physics have not so far been tested in real engineering problems. An attempt is made to use the causality in diagnosing physical devices. The knowledge about the structure and function of the device has been represented using structural equations. The method of comparative statics is employed in deriving the causal dependencies among the state variables of the device. The causal dependencies which describe the behaviour of a system are used to generate the search space for faulty components of the device to be diagnosed. This has been demonstrated with an example of a motor and pump set. LADY: A LOGIC-BASED ARCHITECTURAL DESIGN P R O G R A M SYSTEM Zsuzsanna Markusz
Computer and Automation Institute of Hungarian Academy of Sciences, Budapest, Hungary The LADY is a Logic-Based Architectural Design program system, written in IBM PC P R O L O G ( M P R O L O G - a Hungarian modulair PROLOG), and can be run on an
Artificial Intelligence in Engineering, 1987, Vol. 2, N o . 2
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Total Research Center, 78470 - St. Remy les Cherreuses, France This paper is a presentation of an Expert System built to help understanding drilling situations by log analysis, and hence prevent risks. First we give some general remarks, then we go on to describe the main fundamentals on which the data processing system is based e.g.: agglutination, closed world assumption, nonmonotonic reasoning, real time inference mechanism, transient anomaly. Knowledge representation is based upon several networks: sensors, temporal constraints, states, rules and rules chaining networks. This knowledge is associated with learning methods and Interaction capabilities. SEMANTICALLY EXTENDED LOGIC P R O G R A M M I N G E N V I R O N M E N T FOR CAD/CAPP APPLICATIONS Vesselin I. Kirov
INTERPROGRAMA Software R & D Institute, Sofia, Bulgaria The tendency of unification, normalization and standardization of design solutions at lower levels and the schemes of their composition at higher levels, taking place in industry at present, serves as an ideal basis for computer-aided modular design. The modular design environment consists of functionally complete, usually redundant, set of parts and units (considered as primitives by convention), which could be combined and composed in different (but a priori determined) ways in order to produce potentially unlimited multiplicitly of regular structures on the basis of a relatively smaller number of functionally equivalent variant design solutions, the latter varying mainly in their structure and parameter values. In the paper a knowledge-representation/ problem-solving language, designed in accordance with the principles of conceptual modelling, is described. It has been developed with computer-aided design (CAD)/computeraided process planning (CAPP) problems in mind but it seems to be applicable to many others as well. The systhesis of an object structure that provides a necessary functionality is considered to be the main design problem, possesing many specific features and requiring a different approach in contrast to many other tasks. EXLOG: AN EXPERT SYSTEM FOR LOGIC SYNTHESIS IN FULL-CUSTOM VLSI DESIGN 3,1. Watanabe, 3'1. lwamoto, T. Yamanouchi, H. Matsuda and D. J. Littleboy
C&C Systems Research Laboratory, NEC Corporation. Kanagawa 213, Japan N. Maeda, 3,1. Kawarabayashi and M. Imahashi
VLSI CAD Engineerm9 Dicision, NEC Corporation This paper describes EXLOG, a knowledgebased CAD tool for logic synthesis in fullcustom VLSI design. EXLOG accepts as input a specification of a functional module of a VLSI circuit, written in Functional Description Language IFDL), and synthesizes from that specification a gate and switch level description in Gate Description Language {GDLL Since the EXLOG process closely follows that used by expert designers, it allows the use of expert knowledge in place of combinatoric search in the design process.
EXLOG is implemented in CNL, an expert systems tool which provides a wide variety of programming paradigms. For design problems of a functional module on the order of I000 gates, EXLOG has produced verified designs of similar size and quality to that of design experts.
LIFT-3: A KNOWLEDGE-BASED SYSTEM F O R P L A N N I N G INSTALLATION PROCESSES IN THE O F F S H O R E INDUSTRY A. Bremdal and S. Kristiansen
Division of Marine Systems Design, Department of Marine Technology, Norwegian Institute of Technology The paper will open by introducing the concept of marine operations and the role these operations play in the offshore related oil industry in the North Sea. As a special case, installation tasks will be discussed. Different engineering aspects related to this will be treated with respect to environment, design of the offshore systems and the planning task involved. Oil fields in the North Sea are characterized by a harsh environment and novel, complex units that support oil welldrilling, oil and gas production and transportation. Careful planning of installation tasks with regard to economy and safety is required. The problem is magnified by project management difficulties on field-development scale and in fitting operations within specific 'weather windows'. Some of the subtasks of these particular installation processes include selection and assignment of vessels and tools, mobilization planning, planning of vessel movements and vessel positions, installation sequences. In this context the existing computer aid will also be discussed briefly. To support the different views in this section some references will be made to field investigations and studies carried out within the oil industry.
K N O W L E D G E BASED STEAM PLANT OPERATION R. Fjellheim and T. Pettersen
Computas Expert Systems, Norway Steamex, the expert system described in this paper, is a support tool for operators of a large steam plant at a major chemical factory. In addition to the central steam generation facility (5 boilers, 180-250 tons/hour production), the plant comprises three separate distribution nets (operating at different steam pressure levels), and several hundred steam consumers. The main goal of the Steamex system is to give advice on improving fuel economy of the plant, but also to assist operators in assessing the system state and to rapidly diagnose causes for deviant behaviour of the steam boilers and distribution nets. Steamex is an open-loop system, i.e., provides advice to the operator, who then has to decide whether to follow the advice or not. The system is implemented in a modular fashion, with the main modules being state identification (including derivation of states not directly observable), situation assessment (translation of numerical to qualitative statements), and fuel optimization (based on fluctuating oil/electricity prices). In addition, there are modules for interfacing to the process (fuel consumption meters, steam pressure sensors, etc.) and to the operator through a graphical screen.
GEAREX: A UNIX BASED GEARBOX SELECTION EXPERT SYSTEM Gautam Bose and C. S. Krislmamoorthy
CAD~CAM Programme. Indian Institute of Technology, Madras-600 036, India This paper describes a 'Gearbox Selection Expert System" for general purpose industrial gearbox selection. Initially the nature of the problem is examined and the strategy adopted is explained. Then the type of knowledge representation is detailed. The key features of GEAREX are the use of objects, rules and a relational database management system (RDBMS) for representing the active and static knowledge bases. The system has been developed on a UNIX based minicomputer and implemented using "C" language.
EXPLANATORY K N O W L E D G E TOOLS FOR EXPERT SYSTEMS R. Dieng, O. Corby and P. Haren
INR1A, Centre de Sophia-Antipolis, 06565 Valbonne Cedex, France In this paper, we propose some idea in order to express general principles of the reasoning of an expert system and to provide userdepending explanations: filter reasoning trace and knowledge base according to user's model and detail level; define a class Explanation and describe, through a hierarchy of subclasses, different explanation levels; bind Explanation objects (instances of the class Explanation) to interesting objects for the user; use a mechanism of active values in order to trigger explanations at each modification of the objects to explain; build an explainer expert system, provided with explanation rules and observing the other expert system during or after reasoning. We show how those ideas can be implemented in SMECI shell (Cooperating Expert Systems for Civil Engineering Design): we use its knowledge representation (frames and rules divided in rulesets) and its reasoning mode (possibility for several expert systems to work at the same time). DIAGNOSIS USING CAUSAL DEPENDENCIES Vijay Baudekar
Siemens Coprorate Research, 8000 Munich 83, FRG Theories of qualitative physics have not so far been tested in real engineering problems. An attempt is made to use the causality in diagnosing physical devices. The knowledge about the structure and function of the device has been represented using structural equations. The method of comparative statics is employed in deriving the causal dependencies among the state variables of the device. The causal dependencies which describe the behaviour of a system are used to generate the search space for faulty components of the device to be diagnosed. This has been demonstrated with an example of a motor and pump set. LADY: A LOGIC-BASED ARCHITECTURAL DESIGN P R O G R A M SYSTEM Zsuzsanna Markusz
Computer and Automation Institute of Hungarian Academy of Sciences, Budapest, Hungary The LADY is a Logic-Based Architectural Design program system, written in IBM PC P R O L O G ( M P R O L O G - a Hungarian modulair PROLOG), and can be run on an
Artificial Intelligence in Engineering, 1987, Vol. 2, N o . 2
123