Yuval Lirov - Academia.edu (original) (raw)

Papers by Yuval Lirov

Research paper thumbnail of A locally optimal fast obstacle-avoiding path-planning algorithm

Mathematical Modelling, 1987

Two algorithms to compute the shortest collision-free paths in the Euclidean plane are presented.... more Two algorithms to compute the shortest collision-free paths in the Euclidean plane are presented. The f obstacles are assumed to be described by disjoint convex polygons having N vertices in total. After preprocessing time O(N + flog N), a suboptimal shortest path between two arbitrary query points can be found in O(f+ Nlog N) time using Dijkstra's algorithm and in O(N) time using the A* algorithm. The space complexity is O(N + f).

Research paper thumbnail of Artificial intelligence methods in decision and control systems

Artificial intelligence methods have been applied to the design and implementation of some decisi... more Artificial intelligence methods have been applied to the design and implementation of some decision and control systems. A so-called semantic approach to control and decisions was developed and artificial intelligence methods were used to provide a realizable implementation. These concepts were tested using applications from robust identification and control of time varying systems, intelligent navigation and intelligent simulation of differential games. An aspect of a generalized travelling salesman problem was solved and intelligent simulation of differential games was implemented in Prolog using an example system for automated learning by tactical decision systems in air combat. These implementations were successful and provide several advantages over traditional approaches. The limitations of these concepts were identified and suggestions for future work are made.

Research paper thumbnail of Expert systems approach for generalized traveling salesman problem

Guidance, Navigation and Control Conference, Aug 17, 1987

Research paper thumbnail of On the brown method of exponential smoothing

Operations Research Letters, Apr 1, 1982

In the literature the Brown Method is often recommended for forecasting with the smoothing consta... more In the literature the Brown Method is often recommended for forecasting with the smoothing constant @a = 0.1 or @a = 0.2. We describe an experiment for checking the recommendation, the results of which indicate that it has severe drawbacks. An alternative is suggested.

Research paper thumbnail of Combined Control and Diagnosis for Complex Processes: An Intelligent Control Approach

Expert Systems in Engineering Applications, 1993

The application of computer technology to the management of complex systems seeks to address a wi... more The application of computer technology to the management of complex systems seeks to address a widely varying set of needs and objectives. The specifics of these needs depend heavily on the type of technology for which the support is intended. For example, in computer or communication systems, the resource management issue dominates: we seek efficient utilization of expensive resources. In aerospace applications, computer control is an integrated part of operations, and timely response to stimuli predominates in avoidance of catastrophic scenarios. In manufacturing system applications, the dominating desiderata are those of quality and cost-effective functional execution.

Research paper thumbnail of Artificial-intelligence methods in decision and control systems

Artificial intelligence methods have been applied to the design and implementation of some decisi... more Artificial intelligence methods have been applied to the design and implementation of some decision and control systems. A so-called semantic approach to control and decisions was developed and artificial intelligence methods were used to provide a realizable implementation. These concepts were tested using applications from robust identification and control of time varying systems, intelligent navigation and intelligent simulation of differential games. An aspect of a generalized travelling salesman problem was solved and intelligent simulation of differential games was implemented in Prolog using an example system for automated learning by tactical decision systems in air combat. These implementations were successful and provide several advantages over traditional approaches. The limitations of these concepts were identified and suggestions for future work are made.

Research paper thumbnail of On the brown method of exponential smoothing

Operations Research Letters, 1982

In the literature the Brown Method is often recommended for forecasting with the smoothing consta... more In the literature the Brown Method is often recommended for forecasting with the smoothing constant @a = 0.1 or @a = 0.2. We describe an experiment for checking the recommendation, the results of which indicate that it has severe drawbacks. An alternative is suggested.

Research paper thumbnail of Awkward: toward database reasoning

AI Expert archive, Oct 1, 1989

Research paper thumbnail of Comments on "A New CT-Aided Stereotactic Neurosurgery Technique

IEEE Transactions on Biomedical Engineering, 1986

The method given for finding the position of a target in three-dimensional space from a CT image ... more The method given for finding the position of a target in three-dimensional space from a CT image is incorrect. The solution is Manuscript

Research paper thumbnail of Artificial intelligence modelling of control systems

SIMULATION, 1988

The field of control systems simulation needs artificial intelligence technology as much as exper... more The field of control systems simulation needs artificial intelligence technology as much as expert systems need systems simulation tools. A functional approach for the design of Expert Systems that perform model generations and simulations is proposed. A differential games simulator design is chosen to exemplify the above ideas. The discrete-event approach, based on the geometry of the game is proposed. Results are comparable with the simu lation results obtained using the imperative approach, but the interrogative approach offers faster execution and clearer sim ula tor definition. Knowledge representation of the differential games models is described using Semantic Networks. The model genera tion methodology is a blend of several problem-solving para digms, and the hierarchical dynamic goal system construction serves as the basis for model generation. Prolog-based imple mentation of the system is suggested.

Research paper thumbnail of Do Expert Systems 7hwHen Demoawey?

The social effects of new technologies are hotly debated time and again. New technologies in gene... more The social effects of new technologies are hotly debated time and again. New technologies in general and knowledgebased systems in particular introduce new capabilities and new moral dilemmas. Expert systems, which have already caused profound effects on our lives, complicate matters in a new way: It is now possible to process vast amounts of information and knowledge about everyone. One dilemma is how to maximize expert systems’cultural and social effects without abusing the rights of individual members of society. My position is that we can achieve a satisfactory balance only by introducing appropriate legal procedures and institutions to enforce those procedures. The possible misapplication of expert systems would not be a consequence of high expert-system intelligence (or the lack of it), but rather of our own. I’ll describe my point of view using the perspectives of two recent IEEE Expert articles dealing with the same issue. To label the corresponding approaches with a symboli...

Research paper thumbnail of Optimal dimensioning of counterpropagation neural networks

IJCNN-91-Seattle International Joint Conference on Neural Networks

The absence of automated tools in the area of automated neural network design can be explained by... more The absence of automated tools in the area of automated neural network design can be explained by the corresponding paucity of rigorous neural network composition techniques. The author suggests a hybrid architecture as the basis for a computer-aided neural network engineering tool. Such a tool is expected to complete automatically the minute yet important neural network architecture details. The author demonstrates the approach by developing an automatic counterpropagation neural network design module. It includes a mechanized Kohonen layer configurator, which combines A* and simulated annealing search techniques to achieve both automated dimensioning of the layer and simultaneous selection of its weights.<<ETX>>

Research paper thumbnail of Surviving large-scale distributed computing powerdowns

Research paper thumbnail of Systematic invention for knowledge engineering

Research paper thumbnail of A process for producing an expert system for system troubleshooting

Research paper thumbnail of Online search + logic programming = subject bibliography: an expert systems approach to bibliographic processing

Online Review

In this paper we propose a new method for the creation of subject bibliographies. Our method cons... more In this paper we propose a new method for the creation of subject bibliographies. Our method consists of two phases: first, the raw bibliographical material is downloaded from an online bibliographical database (e.g. DIALOG), and then this material is processed using knowledge‐based means. We apply a meta‐programming approach in which the raw bibliographic material is viewed as a logic program upon which we develop a second‐order logic program. The second‐order program creates the subject bibliography by operating a rule base and the first‐order logic program. The entire system, named REX, was written in PROLOG and used to create automatically a subject bibliography on Applications of Logic Programming in Decision and Control.

Research paper thumbnail of Flight and fire control knowledge representation

Proceedings of the 28th IEEE Conference on Decision and Control

Abstract The development of a conceptual framework for an operational, onboard, real-time multipr... more Abstract The development of a conceptual framework for an operational, onboard, real-time multiprocessing computer system, capable of assisting the pilot in flight and fire control decisions, ie a tactical decision aiding expert system, is discussed. Air combat is ...

Research paper thumbnail of Intelligent control and diagnosis of chemical etch processes

Proceedings. ICCON IEEE International Conference on Control and Applications

Ckmical etching is sensitive to a number of process variables which need to be maintained in a ce... more Ckmical etching is sensitive to a number of process variables which need to be maintained in a certain relationship to achieve good quality product. We describe M intelligent control system to support chemical etch processes. The system serves siinultaneously two purposes: first it dispenses on-line expert advice on how to control chemical etching and, secondly, it constitutes a repository of qualitative knowledge and thus serves to codify the folklore of &aline etch control. Ttrp expert system has been prototyped using PROLOG and installed on the factory fkar.

Research paper thumbnail of Time-variant decision support systems

Conference Proceedings., IEEE International Conference on Systems, Man and Cybernetics

Intelligent decision systems in time-invariant situations must be able to manipulate time-variant... more Intelligent decision systems in time-invariant situations must be able to manipulate time-variant data and functions. The authors present an algorithm for the following dynamic computational problem: given a set of continuous functions, keep track efficiently of their order in their domain. The algorithm has time complexity of O(nlog/sub 2/n+K min(log/sub 2/n, log/sub 2/K)), where n is the number of functions and K is the total number of intersections between the functions. The solution provides for a convenient object-oriented view of the time-variant priority queue. Contrary to the abstract data type consisting of the array (data structure) and the associated utilities (push, pop), the time-variant priority queue maintains a private state as the data change.<<ETX>>

Research paper thumbnail of Intelligent control of dynamical systems. I. Robust identification and control of linear time-varying systems

Proceedings of the 27th IEEE Conference on Decision and Control

The authors propose an artificial-intelligence-based design procedure which addresses the followi... more The authors propose an artificial-intelligence-based design procedure which addresses the following robust adaptive stabilization problem: given the inputs and outputs of an unknown time-varying system, construct a family of plants one of which is the true system, and obtain a simultaneous stabilizer for the above family. The procedure consists of replacing the classical plant/compensator control loop by a higher level control system consisting of three collaborating expert systems. The procedure is robust, since it utilizes a simultaneous design scheme with a simultaneous identifier. From the point of view of computation, a heuristic scheme is designed, and an admissible heuristic is constructed even for a tree with time-varying cost functions.<<ETX>>

Research paper thumbnail of A locally optimal fast obstacle-avoiding path-planning algorithm

Mathematical Modelling, 1987

Two algorithms to compute the shortest collision-free paths in the Euclidean plane are presented.... more Two algorithms to compute the shortest collision-free paths in the Euclidean plane are presented. The f obstacles are assumed to be described by disjoint convex polygons having N vertices in total. After preprocessing time O(N + flog N), a suboptimal shortest path between two arbitrary query points can be found in O(f+ Nlog N) time using Dijkstra's algorithm and in O(N) time using the A* algorithm. The space complexity is O(N + f).

Research paper thumbnail of Artificial intelligence methods in decision and control systems

Artificial intelligence methods have been applied to the design and implementation of some decisi... more Artificial intelligence methods have been applied to the design and implementation of some decision and control systems. A so-called semantic approach to control and decisions was developed and artificial intelligence methods were used to provide a realizable implementation. These concepts were tested using applications from robust identification and control of time varying systems, intelligent navigation and intelligent simulation of differential games. An aspect of a generalized travelling salesman problem was solved and intelligent simulation of differential games was implemented in Prolog using an example system for automated learning by tactical decision systems in air combat. These implementations were successful and provide several advantages over traditional approaches. The limitations of these concepts were identified and suggestions for future work are made.

Research paper thumbnail of Expert systems approach for generalized traveling salesman problem

Guidance, Navigation and Control Conference, Aug 17, 1987

Research paper thumbnail of On the brown method of exponential smoothing

Operations Research Letters, Apr 1, 1982

In the literature the Brown Method is often recommended for forecasting with the smoothing consta... more In the literature the Brown Method is often recommended for forecasting with the smoothing constant @a = 0.1 or @a = 0.2. We describe an experiment for checking the recommendation, the results of which indicate that it has severe drawbacks. An alternative is suggested.

Research paper thumbnail of Combined Control and Diagnosis for Complex Processes: An Intelligent Control Approach

Expert Systems in Engineering Applications, 1993

The application of computer technology to the management of complex systems seeks to address a wi... more The application of computer technology to the management of complex systems seeks to address a widely varying set of needs and objectives. The specifics of these needs depend heavily on the type of technology for which the support is intended. For example, in computer or communication systems, the resource management issue dominates: we seek efficient utilization of expensive resources. In aerospace applications, computer control is an integrated part of operations, and timely response to stimuli predominates in avoidance of catastrophic scenarios. In manufacturing system applications, the dominating desiderata are those of quality and cost-effective functional execution.

Research paper thumbnail of Artificial-intelligence methods in decision and control systems

Artificial intelligence methods have been applied to the design and implementation of some decisi... more Artificial intelligence methods have been applied to the design and implementation of some decision and control systems. A so-called semantic approach to control and decisions was developed and artificial intelligence methods were used to provide a realizable implementation. These concepts were tested using applications from robust identification and control of time varying systems, intelligent navigation and intelligent simulation of differential games. An aspect of a generalized travelling salesman problem was solved and intelligent simulation of differential games was implemented in Prolog using an example system for automated learning by tactical decision systems in air combat. These implementations were successful and provide several advantages over traditional approaches. The limitations of these concepts were identified and suggestions for future work are made.

Research paper thumbnail of On the brown method of exponential smoothing

Operations Research Letters, 1982

In the literature the Brown Method is often recommended for forecasting with the smoothing consta... more In the literature the Brown Method is often recommended for forecasting with the smoothing constant @a = 0.1 or @a = 0.2. We describe an experiment for checking the recommendation, the results of which indicate that it has severe drawbacks. An alternative is suggested.

Research paper thumbnail of Awkward: toward database reasoning

AI Expert archive, Oct 1, 1989

Research paper thumbnail of Comments on "A New CT-Aided Stereotactic Neurosurgery Technique

IEEE Transactions on Biomedical Engineering, 1986

The method given for finding the position of a target in three-dimensional space from a CT image ... more The method given for finding the position of a target in three-dimensional space from a CT image is incorrect. The solution is Manuscript

Research paper thumbnail of Artificial intelligence modelling of control systems

SIMULATION, 1988

The field of control systems simulation needs artificial intelligence technology as much as exper... more The field of control systems simulation needs artificial intelligence technology as much as expert systems need systems simulation tools. A functional approach for the design of Expert Systems that perform model generations and simulations is proposed. A differential games simulator design is chosen to exemplify the above ideas. The discrete-event approach, based on the geometry of the game is proposed. Results are comparable with the simu lation results obtained using the imperative approach, but the interrogative approach offers faster execution and clearer sim ula tor definition. Knowledge representation of the differential games models is described using Semantic Networks. The model genera tion methodology is a blend of several problem-solving para digms, and the hierarchical dynamic goal system construction serves as the basis for model generation. Prolog-based imple mentation of the system is suggested.

Research paper thumbnail of Do Expert Systems 7hwHen Demoawey?

The social effects of new technologies are hotly debated time and again. New technologies in gene... more The social effects of new technologies are hotly debated time and again. New technologies in general and knowledgebased systems in particular introduce new capabilities and new moral dilemmas. Expert systems, which have already caused profound effects on our lives, complicate matters in a new way: It is now possible to process vast amounts of information and knowledge about everyone. One dilemma is how to maximize expert systems’cultural and social effects without abusing the rights of individual members of society. My position is that we can achieve a satisfactory balance only by introducing appropriate legal procedures and institutions to enforce those procedures. The possible misapplication of expert systems would not be a consequence of high expert-system intelligence (or the lack of it), but rather of our own. I’ll describe my point of view using the perspectives of two recent IEEE Expert articles dealing with the same issue. To label the corresponding approaches with a symboli...

Research paper thumbnail of Optimal dimensioning of counterpropagation neural networks

IJCNN-91-Seattle International Joint Conference on Neural Networks

The absence of automated tools in the area of automated neural network design can be explained by... more The absence of automated tools in the area of automated neural network design can be explained by the corresponding paucity of rigorous neural network composition techniques. The author suggests a hybrid architecture as the basis for a computer-aided neural network engineering tool. Such a tool is expected to complete automatically the minute yet important neural network architecture details. The author demonstrates the approach by developing an automatic counterpropagation neural network design module. It includes a mechanized Kohonen layer configurator, which combines A* and simulated annealing search techniques to achieve both automated dimensioning of the layer and simultaneous selection of its weights.<<ETX>>

Research paper thumbnail of Surviving large-scale distributed computing powerdowns

Research paper thumbnail of Systematic invention for knowledge engineering

Research paper thumbnail of A process for producing an expert system for system troubleshooting

Research paper thumbnail of Online search + logic programming = subject bibliography: an expert systems approach to bibliographic processing

Online Review

In this paper we propose a new method for the creation of subject bibliographies. Our method cons... more In this paper we propose a new method for the creation of subject bibliographies. Our method consists of two phases: first, the raw bibliographical material is downloaded from an online bibliographical database (e.g. DIALOG), and then this material is processed using knowledge‐based means. We apply a meta‐programming approach in which the raw bibliographic material is viewed as a logic program upon which we develop a second‐order logic program. The second‐order program creates the subject bibliography by operating a rule base and the first‐order logic program. The entire system, named REX, was written in PROLOG and used to create automatically a subject bibliography on Applications of Logic Programming in Decision and Control.

Research paper thumbnail of Flight and fire control knowledge representation

Proceedings of the 28th IEEE Conference on Decision and Control

Abstract The development of a conceptual framework for an operational, onboard, real-time multipr... more Abstract The development of a conceptual framework for an operational, onboard, real-time multiprocessing computer system, capable of assisting the pilot in flight and fire control decisions, ie a tactical decision aiding expert system, is discussed. Air combat is ...

Research paper thumbnail of Intelligent control and diagnosis of chemical etch processes

Proceedings. ICCON IEEE International Conference on Control and Applications

Ckmical etching is sensitive to a number of process variables which need to be maintained in a ce... more Ckmical etching is sensitive to a number of process variables which need to be maintained in a certain relationship to achieve good quality product. We describe M intelligent control system to support chemical etch processes. The system serves siinultaneously two purposes: first it dispenses on-line expert advice on how to control chemical etching and, secondly, it constitutes a repository of qualitative knowledge and thus serves to codify the folklore of &aline etch control. Ttrp expert system has been prototyped using PROLOG and installed on the factory fkar.

Research paper thumbnail of Time-variant decision support systems

Conference Proceedings., IEEE International Conference on Systems, Man and Cybernetics

Intelligent decision systems in time-invariant situations must be able to manipulate time-variant... more Intelligent decision systems in time-invariant situations must be able to manipulate time-variant data and functions. The authors present an algorithm for the following dynamic computational problem: given a set of continuous functions, keep track efficiently of their order in their domain. The algorithm has time complexity of O(nlog/sub 2/n+K min(log/sub 2/n, log/sub 2/K)), where n is the number of functions and K is the total number of intersections between the functions. The solution provides for a convenient object-oriented view of the time-variant priority queue. Contrary to the abstract data type consisting of the array (data structure) and the associated utilities (push, pop), the time-variant priority queue maintains a private state as the data change.<<ETX>>

Research paper thumbnail of Intelligent control of dynamical systems. I. Robust identification and control of linear time-varying systems

Proceedings of the 27th IEEE Conference on Decision and Control

The authors propose an artificial-intelligence-based design procedure which addresses the followi... more The authors propose an artificial-intelligence-based design procedure which addresses the following robust adaptive stabilization problem: given the inputs and outputs of an unknown time-varying system, construct a family of plants one of which is the true system, and obtain a simultaneous stabilizer for the above family. The procedure consists of replacing the classical plant/compensator control loop by a higher level control system consisting of three collaborating expert systems. The procedure is robust, since it utilizes a simultaneous design scheme with a simultaneous identifier. From the point of view of computation, a heuristic scheme is designed, and an admissible heuristic is constructed even for a tree with time-varying cost functions.<<ETX>>