Given that corrective-maintenance costs already dominate the software life cycle and look set to increase significantly, reliability in the form of reducing such costs should be the most important software improvement...
详细信息
Given that corrective-maintenance costs already dominate the software life cycle and look set to increase significantly, reliability in the form of reducing such costs should be the most important software improvement goal. Yet the results are not promising when we review recent corrective-maintenance data for big systems in general and for OO in particular-possibly because of mismatches between the OO paradigm and how we think.
Method schemas were proposed as a formal model of object-oriented languages. A method schema S is called consistent if, for each method invocation during the execution of S, a method definition to be bound to the invo...
详细信息
Method schemas were proposed as a formal model of object-oriented languages. A method schema S is called consistent if, for each method invocation during the execution of S, a method definition to be bound to the invoked method name is uniquely determined. However, the consistency testing problem is known to be undecidable in general. This paper presents an algorithm which analyzes the consistency of a given method schema. The algorithm decides the consistency problem in polynomial time for monadic method schemas. We also provide an incremental algorithm for testing consistency after updates of a method schema.
Real-time and on-line optimisation methods for control of large-scale systems use real-time sensor data to optimise the system's performance. The data need to be pre-processed for faults to safeguard against inapp...
详细信息
Real-time and on-line optimisation methods for control of large-scale systems use real-time sensor data to optimise the system's performance. The data need to be pre-processed for faults to safeguard against inappropriate control actions. Conventional real-time signal processing techniques are likely to fail because of the system's complexity and the processing speed required. A generic, real-time knowledge-based system-FLASH (FLexible Al for Signal Handling in real time)-has been developed to detect, diagnose and replace faulty sensor readings. Its effectiveness in processing signals for control in a complex, sensor-rich environment has been demonstrated in real-time environmental control of greenhouse microclimate. (C) 1998 Elsevier Science B.V. All rights reserved.
This paper describes the development of an intelligent process-control system for the production of fiber-reinforced organic polymeric composites. The composite material consists of a polymer matrix (polyamide resin F...
详细信息
This paper describes the development of an intelligent process-control system for the production of fiber-reinforced organic polymeric composites. The composite material consists of a polymer matrix (polyamide resin F174) and high-modulus quartz-fiber reinforcement. This composite material has good mechanical properties at high temperatures, and possesses a low dielectric constant, making it suitable for applications in missile radomes. The problem is that the raw materials are chemically reactive, and the process-control system must enable adaptation to variations in the temperature-time exposure of the raw materials and/or variations which may occur in the materials received from different suppliers. The uniqueness of the control system lies in that it is self-directing, and relies on information derived from sensors (laser fiber-optic probes and dielectric sensors) placed within the material. In addition, a materials-transformation model based on the chemical kinetics of the polymerization process calculates a number of key polymer parameters, such as degree of imidization, degree of cure, molecular weight distribution, and polydispersity ratio in situ. The collective ability to collect high-quality sensor information, to run sophisticated but robust process models in real time, to make complex decisions using artificial intelligence (AI), and to implement these decisions for controlling the structure of the actual material being processed represents a significant breakthrough in materials and process capability in this field. The focus of this work, measuring and controlling the physical and chemical properties of the material, rather than the physical attributes of the processing machinery, is an important paradigm shift. (C) 1998 Elsevier Science Ltd. All rights reserved.
作者：
Xu, DXNanjing Univ
Dept Comp Sci & Technol State Key Lab Novel Software Technol Nanjing 210093 Peoples R China
This article presents an object-oriented logic framework, I,KO, for the dependable development of knowledge based systems. Based on logical objects which are viewed as abstractions with states, constraints, behaviors ...
详细信息
This article presents an object-oriented logic framework, I,KO, for the dependable development of knowledge based systems. Based on logical objects which are viewed as abstractions with states, constraints, behaviors and nonmonotonic inheritance, a hybrid knowledge representation amalgamating rule, frame, semantics network and blackboard is available for both most structured end flat knowledge and requirements of knowledge based systems. After the iterations of specification modification and verification in terms of knowledge acquisition activities, prototypes are correctly formed. The LKO methodology, applying the concepts of rapid prototyping, top-down design and object-orientation, is designed to deal with changing and incomplete requirements and to provide multiple abstract models of the domain, where formal methods might be used at each abstract level. (C) 1998 Elsevier Science B.V. All rights reserved.
This paper presents a logic based language, SAFIN, for developing networked software agents. It integrates agent-orientedprogramming, KQML and basic mobile techniques to support intelligent behaviors, software intero...
详细信息
This paper presents a logic based language, SAFIN, for developing networked software agents. It integrates agent-orientedprogramming, KQML and basic mobile techniques to support intelligent behaviors, software interoperatablity and code transportability. As prototype based logic objects, agents are composed of network connections, knowledge bases (facts and beliefs), databases, behaviors, constraints, services, goals and KQML performatives. An approach to non-monotonic inheritance with both predicate level and clause level knowledge reuse is proposed and formally defined. Multi-level components and the interfaces to FTP services and relational database systems are also provided for developing specific distributed agents. (C) 1998 Elsevier Science B.V. All rights *** paper presents a logic based language, SAFIN, for developing networked software agents. It integrates agent-orientedprogramming, KQML and basic mobile techniques to support intelligent behaviors, software interoperatablity and code transportability. As prototype based logic objects, agents are composed of network connections, knowledge bases (facts and beliefs), databases, behaviors, constraints, services, goals and KQML performatives. An approach to non-monotonic inheritance with both predicate level and clause level knowledge reuse is proposed and formally defined. Multi-level components and the interfaces to FTP services and relational database systems are also provided for developing specific distributed agents. (C) 1998 Elsevier Science B.V. All rights reserved.
The objective of the European project STORMS (software tools for the optimization of resources in mobile systems) is to develop a software tool to be used for the design and the planning of the future universal mobile...
详细信息
The objective of the European project STORMS (software tools for the optimization of resources in mobile systems) is to develop a software tool to be used for the design and the planning of the future universal mobile telecommunication system (UMTS). In this context the ParFlow method permits the simulation of outdoor radio wave propagation in urban environment, modelling the physical system in terms of the motion of fictitious microscopic particles over a lattice. This paper gives an overview of the ParFlow method, and reports the design and the implementation of ParFlow++, an object-oriented irregular parallel software for urban outdoor radio wave propagation prediction. Copyright (C) 1998 Elsevier Science B.V.
The efficient solving of process control problems often requires manipulating a wide spectrum of knowledge representations ranging from analytical knowledge to qualitative knowledge. These tendencies have been causing...
详细信息
The efficient solving of process control problems often requires manipulating a wide spectrum of knowledge representations ranging from analytical knowledge to qualitative knowledge. These tendencies have been causing a growing interest for methods that are flexible enough to accommodate knowledge-based paradigms. In the paper, the simulator design of the amorphous SiO2 precipitation process is described. From the control point of view, the process is a typical semibatch process containing discrete, as well as continuous dynamics. The simulator is developed in G2, which is an environment for the development of real-time expert systems and has been effectively used on a problem containing a great diversity of model descriptions. (C) 1998 Elsevier Science B.V. All rights reserved.
Flexible manufacturing cells (FMC) may be considered the most significant development in small-batch manufacturing. Setting-up and operating costs of FMC prove to be the most major hindrance to their large-scale imple...
详细信息
Flexible manufacturing cells (FMC) may be considered the most significant development in small-batch manufacturing. Setting-up and operating costs of FMC prove to be the most major hindrance to their large-scale implementation and use, particularly by small and medium size industries. Incompatibilities between the different components constituting the cells and the lack of a unified language/approach to programming and coordinating them are cited as the cause of the complexity of setting up and subsequently operating the cells. In order to eliminate these difficulties, a new philosophy for setting-up, programming and control of FMC has been developed. This paper reports the effort to develop this new unified manufacturing instruction set and its environment, called here "UniSet", its philosophy and some of the components of the UniSet environment. UniSet has been developed as a non-exclusive unified manufacturing instruction set, based on comparisons of the prevailing machine tool and programming primitives. UniSet allows programmers to deal with only one instruction set, if they so desire, in a single coherent environment, rather than numerous machine programming languages. The software system is coded in an object-oriented programming (OOP) language, Smalltalk, and derives its paradigm from the OO philosophy. Test results are also included to demonstrate the applicability of the approach employed. (C) 1998 Elsevier Science Ltd. All rights reserved.
The object management architecture (OMA) has been recognized as a de facto standard in the development of object services in a distributed computing environment. In a distributed system, the provision for failure-reco...
详细信息
The object management architecture (OMA) has been recognized as a de facto standard in the development of object services in a distributed computing environment. In a distributed system, the provision for failure-recovery is always a vital design issue. However, the fault-tolerant service has not been extensively considered in the current OMA framework, despite the fact that an increasing number of useful common services and common facilities have been adopted in OMA. In this paper, we propose a fault-tolerance developing environment, called Phoinix, which is compatible to the OMA framework. In Phoinix, object services can be developed with embedded fault-tolerance capability to tolerate both hardware and software failures. The fault-tolerance capability in Phoinix is classified into two levels: restart, and rollback-recovery;when the fault-tolerance capability enhances as the level increases. Currently, Phoinix is ported on Orbix 2.0 and on SunOS 4.2. In this paper, the design and implementation of Phoinix is presented and its performance is evaluated. (C) 1998 Elsevier Science B.V.
暂无评论