Alarm processing is a traditional feature of energy-management systems (EMS), and has not changed significantly over several generations of SCADA design. This paper describes two parts of a project between the Univers...
详细信息
Alarm processing is a traditional feature of energy-management systems (EMS), and has not changed significantly over several generations of SCADA design. This paper describes two parts of a project between the University of Dundee and Scottish Hydro-Electric pie (HE) on the use of an Artificial Intelligence system for alarm processing and fault diagnosis. The first part of the project was an overview and comparison study of three real-time object-oriented toolkits: Muse, Kappa and Nexpert object. The study is based on the capabilities of such toolkits to handle the power system alarm processing, integration with external programs and real-time databases, portability, price and execution speed. Some advantages and drawbacks of each toolkit are also pointed out. The second part of the project was the implementation of an object-oriented expert system using the KappaPC toolkit operating on a 486 IBM compatable PC under Microsoft Windows 3.1. The toolkit was chosen in the first part of the project, for the initial development of a prototype real-time alarm-processing and fault-diagnosis system. The structure of the object-oriented expert system captures the heuristic knowledge used for power system operation. The knowledge-base is automatically updated by the existing SCADA system as the power system's status changes. The paper also describes the features of the real-time object-oriented expert system;these include the need for fast, deep-level reasoning, easy maintainability of the object-oriented programming and the end user's interface.
This paper presents techniques for solving systems of equations arising in finite element applications using a localized, tensor-based approach. The approach is localized in that a major part of the solution responsib...
详细信息
This paper presents techniques for solving systems of equations arising in finite element applications using a localized, tensor-based approach. The approach is localized in that a major part of the solution responsibility is delegated to vector degree-of-freedom objects, rather than residing solely in a global solver working on a monolithic data structure. The approach is tensor-based in that the fundamental quantities used for computation are considered to be second-order tensors. The localized data structure strategy provides the benefits of an efficient sparse and symmetric storage scheme without requiring complex implementation code. The tensor-based aspect of the approach can bring substantial performance benefits by increasing the granularity at which solution algorithms deal with their data. Java and C++ implementations of interactive finite element programs are used to demonstrate performance that is competitive with other available solvers, especially in the case of problems for which interactive analysis is feasible on commonly available hardware. (C) 2003 Elsevier Science Ltd. All rights reserved.
An object-oriented scheduling system for a job-shop manufacturing cell has been developed and tested. A powerful optimization technique based on genetic algorithms was used to improve the routing of subassembly parts ...
详细信息
An object-oriented scheduling system for a job-shop manufacturing cell has been developed and tested. A powerful optimization technique based on genetic algorithms was used to improve the routing of subassembly parts in the manufacturing cell. The scheduling system is composed of three interactive modules: the due date algorithms, the genetic algorithms, and the manufacturing cell simulator. These modules exchange information to accomplish 'genetic optimization' and to fulfill time-dependent and technological constraints simultaneously, using a composite objective function. The due date algorithms use the production sequences and processing times of individual parts of a single product to generate production priorities. The genetic algorithms module creates a population of feasible machine routings and schedules, and passes it on to the manufacturing cell simulator. The manufacturing cell simulator performs the production plans under different scheduling configurations. The genetic algorithms module uses the fitness value of each scheduling alternative progressively to improve the production schedule until a convergence criterion is satisfied. (C) 1997 Elsevier Science B.V.
Program slicing is a decomposition technique that deals with extracting those statements relevant to a particular computation. The authors propose a novel algorithm for computing dynamic slice of distributed object-or...
详细信息
Program slicing is a decomposition technique that deals with extracting those statements relevant to a particular computation. The authors propose a novel algorithm for computing dynamic slice of distributed object-oriented programs. The proposed algorithm incorporates graph colouring strategy to compute slice. But to achieve the goal efficiently, the authors have contradicted some key constraints of the traditional graph colouring technique. The state restriction of the slicing criterion is also considered along with dependence analysis while computing slice. The advantage of the proposed algorithm is that it is efficient and faster than the existing algorithms.
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...
详细信息
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.
An explanation is given of showing a computer what to do by directly manipulating objects, as opposed to giving it instructions using a programming language. The authors demonstrate how showing can take advantage of a...
详细信息
An explanation is given of showing a computer what to do by directly manipulating objects, as opposed to giving it instructions using a programming language. The authors demonstrate how showing can take advantage of a standard user interface and the consistency of a user interface paradigm. They discuss prototyping in the Oregon Speedcode Universe, a programming system for writing programs without programming languages
This paper is organized as follows. Part A presents the context of reconfiguring transitic systems and the main idea in implementing the decision step. It comprises sections 1 to 3. Section 3 presents an example that ...
详细信息
This paper is organized as follows. Part A presents the context of reconfiguring transitic systems and the main idea in implementing the decision step. It comprises sections 1 to 3. Section 3 presents an example that illustrates the concepts presented in the next sections. Parts B and C express the models and principles used to simulate transitic systems, the result of which will be helpful for choosing the new configuration. Part B focuses mainly on models. It comprises sections 4 to 6. Part C focuses mainly on simulation principles. It comprises sections 7 to 10.
Minimum cost wavelength-path routing and wavelength allocation of multiwavelength alloptical transport networks using a genetic-algorithm (GA)/heuristic hybrid approach is described. A cost model is adopted which inco...
详细信息
Minimum cost wavelength-path routing and wavelength allocation of multiwavelength alloptical transport networks using a genetic-algorithm (GA)/heuristic hybrid approach is described. A cost model is adopted which incorporates a dependency on link wavelength requirements. The hybrid algorithm developed uses an object-oriented representation of networks, and incorporates four operators: path mutation, single-point crossover, reroute and shift-out. In addition, an operator-probability adaptation mechanism is employed to improve operator productivity. Experimental results from seven fifteen-node test networks, obtained using a tool for optical network optimisation, modelling and design (NOMaD), suggest the GA/heuristic hybrid approach provides superior results compared to three recent wavelength-allocation heuristics, except when the network cost depends most heavily on wavelength requirement.
This paper presents a computer-aided planning system that is capable of generating assembly sequences for aircraft frame assemblies. The representation scheme for aircraft frame assemblies is first described. Algorith...
详细信息
This paper presents a computer-aided planning system that is capable of generating assembly sequences for aircraft frame assemblies. The representation scheme for aircraft frame assemblies is first described. Algorithms for the automated generation of assembly sequences are then discussed. The planning system takes assembly drawing and bill of material as inputs. In consideration of both the geometric and technical constraints in the planning stage, the system generates an assembly sequence as output. The system has been implemented using an object-oriented approach (C++) and a graphical user interface under MS-Windows. A spar subassembly is used to demonstrate the working of the methodology as well as the implemented system.
In this paper we present an approach to integrating optimisation tools with simulation software to achieve user-defined objectives. A formal protocol is presented, including specific definitions of the requirements of...
详细信息
In this paper we present an approach to integrating optimisation tools with simulation software to achieve user-defined objectives. A formal protocol is presented, including specific definitions of the requirements of the simulator, optimiser, and design interface. A discussion of the mathematical issues and the efficiency of different approaches for computing sensitivities is given. We then discuss the source code modifications necessary to accomplish the integration of simulation and optimisation. (C) 1996 by Elsevier Science Inc.
暂无评论