The analysis of complex neural network models via analytical techniques is often quite difficult due to the large numbers of components involved, and the nonlinearities associated with these components. For this reaso...
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The analysis of complex neural network models via analytical techniques is often quite difficult due to the large numbers of components involved, and the nonlinearities associated with these components. For this reason, simulation is seen as an important tool in neural network research. In this paper we present a framework for simulating neural networks as discrete event nonlinear dynamical systems. This includes neural network models whose components are described by continuous-time differential equations, or by discrete-time difference equations. Specifically, we consider the design and construction of a concurrent object-oriented discrete event simulation environment for neural networks. The use of an object-oriented language provides the data abstraction facilities necessary to support modification and extension of the simulation system at a high level of abstraction. Furthermore, the ability to specify concurrent processing supports execution on parallel architectures. The use of this system is demonstrated by simulating a specific neural network model on a general-purpose parallel computer.
This paper describes a fast, one-step translation method that implements paging on top of segmentation. This method translates a virtual address into a physical address, performing both the segmentation and paging tra...
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This paper describes a fast, one-step translation method that implements paging on top of segmentation. This method translates a virtual address into a physical address, performing both the segmentation and paging translations, with a single TLB read and a short add. Previous methods performed this translation in two steps and required two TLB reads and a long add. Using the fast method, the fine-grain protection and relocation of segmentation combined with paging can be provided with delay and complexity comparable to paging-only systems. This method allows small segments, particularly important in object-oriented programming systems, to be managed efficiently.
A framework for enhancement of conceptual tools for rapid computational prototyping of manufacturing entities is presented. A typical manufacturing entity (i.e. manufacturing system and/or individual part) is hierarch...
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A framework for enhancement of conceptual tools for rapid computational prototyping of manufacturing entities is presented. A typical manufacturing entity (i.e. manufacturing system and/or individual part) is hierarchically represented in a computer and coupled with applications by dividing its information content into three computational elements: data, drawing and user interface. The information content is divided in this way because each of the above elements has a sufficiently distinct requirement for an efficient computer implementation. Although independent advances have taken place in computer data representation by highly efficient and focused data structures, in drawing representation by sophisticated computer graphics, as well as in user interface by a variety of interface media, these advances cannot be directly utilized in the design of a manufacturing entity unless they are efficiently integrated by relatively small programming effort as is described in this rapid prototyping framework. The framework is implemented in object-oriented programming. A breadth of application areas for the framework is illustrated, and specific details are illustrated with reference to depth in one application area.
The authors have developed an architecture simulation toolkit from which a RISC simulator has been built by employing object-oriented software development techniques. object-oriented design makes it easy to extend the...
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The authors have developed an architecture simulation toolkit from which a RISC simulator has been built by employing object-oriented software development techniques. object-oriented design makes it easy to extend the simulated RISC architecture. Equally, more or even different functionality can be incorporated by uniformly extending the framework of the simulator. The basic framework is explained by simulating a subset of the Acorn ARM RISC's instruction set. This instruction set is then extended to provide further functionality by the addition of a multiply with accumulate instruction. The reader is expected to be reasonably conversant with the C+ + programming language and with the basic concepts of object-oriented programming.
Cell control forms an important layer in a hierarchy of control. A cell will typically contain several machine tools, robots and allied material handling equipment. The function of a cell controller is to co-ordinate ...
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Cell control forms an important layer in a hierarchy of control. A cell will typically contain several machine tools, robots and allied material handling equipment. The function of a cell controller is to co-ordinate and control the equipment within the cell so as to achieve high degrees of efficiency. A requirement is that the cell controller should function in real-time. The need to maintain high cell efficiency while having relatively low computation times poses a severe requirement on the design of a cell controller. Previous cell controller predominantly either suffer from relatively long computation times or else handle only a portion of the cell control functions. The aim of this paper is to give a detailed description of the operation of X-Cell, a cell control system that uses object-oriented programming to map cell control functions onto objects. The language used is Scheme, with Scheme objectorientedprogramming System (SCOOPS) providing the object-oriented paradigm. The paper gives a brief overview of the architecture of X-Cell, together with a more detailed description of each of the three main modules: the scheduler, operation dispatcher, and monitor. A brief description of the X-Cell emulator is then given. Finally, an example scenario using X-Cell is given. The overall result is a cell control system that can be adapted for use in a wide variety of manufacturing cells.
A Distributed Problem Solving (DPS) architecture (SCOPE) for the control of Flexible Manufacturing Systems is presented. The controller kernel is intended to be easily adapted for different manufacturing systems, and ...
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A Distributed Problem Solving (DPS) architecture (SCOPE) for the control of Flexible Manufacturing Systems is presented. The controller kernel is intended to be easily adapted for different manufacturing systems, and we propose this as a basis for the standardization of control architectures from the point of view of control system designers. Our concern is the dynamic (rapid) generation of flexible solutions to a control problem with several discrete decision variables. Each node consists of the object class (or classes) that it deals with, its local model (which describes the dynamics of the node), and a set of problem solving agents (knowledge sources), that could be invoked by this node. An object class is represented by a Petri net with an object orientated interpretation (PNO), and acts as a structured local database or a local hypothesis register. The local model indicates the conditions under which this problem solving node could invoke any of its agents, and also when a node demands the services of another node, this demand is formulated through the local model. A node calling for the treatment of its local hypothesis modification does not know the node which will respond. Inside a node its KSs are also disconnected (uncoupled), and react in an opportunistic manner. This control structure permits parallel activation of KSs. The protocols for activation, running, termination (normal and abnormal) and resumption of the different KS types are specified with generic Petri net structures. A detailed description of the problem solving mechanism in SCOPE is given for the activities involving the Batching node.
object-oriented programming apparently provides a great power to organise and manage all elements constituting a software project in a clean and efficient way. This is particularly not true, however, in a multiple pro...
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object-oriented programming apparently provides a great power to organise and manage all elements constituting a software project in a clean and efficient way. This is particularly not true, however, in a multiple project group-development circumstance. This paper presents an approach to solve these problems in a Smalltalk-type environment. Key ideas are configuration inheritance, version synthesis, and functionality mapping.
In this paper, we present a formal requirement specification language, frame-and-rule oriented requirement specification language FRORL, which was developed to facilitate the specification, analysis, and development o...
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In this paper, we present a formal requirement specification language, frame-and-rule oriented requirement specification language FRORL, which was developed to facilitate the specification, analysis, and development of a software system. The surface syntax of FRORL is based on the concepts of frames and production rules which may bear hierarchical relationships among each other, relying on multiple inheritance. However, to provide thorough semantic foundations, FRORL is based on a nonmonotonic variant of Horn-clause logic. Using the machinery of Horn-clause logic, various properties of a FRORL specification can be analyzed. The underlying logic of FRORL has been proven sound and complete. Among the external properties of FRORL are formality, object-orientedness, and wide-spectrum of life cycle phases;intrinsic properties are modularity, provision for incremental development, inheritance, refinement, re-usability, prototyping, and executability;and there is a surrounding environment including a knowledge base, theorem proving support, and graphic support. A software development environment based on FRORL has been implemented using C on a Sun workstation.
This paper introduces a model that combines and extends capabilities of relational and objectoriented systems. Within a simple, statically-typed framework, the model supports abstract data types (ADTs), a multiple in...
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Technological advancements i n programming methodologies and computational power have made expert systems an economical and important solution for manufacturing process control. Expert systems have been widely accepte...
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