Towards expert systems for telecommunications policy analysis

Telecommunications policy analysis is currently a highly complex arena of debate. Systems have been developed by British Telecom which replace traditional simulation models. The paper reviews the progress to date within BT, discusses topics for future research and suggests what can be usefully gained from the application of expert systems to policy analysis and evaluation.     

A survey of evaluation techniques used for expert systems in telecommunications

Hardware and software used within the telecommunications industry must combine great complexity with high reliability. Production and maintenance of communications equipment requires many different kinds of human expertise. There is growing interest in the potential of expert systems to assist, or perhaps to replace, human experts. It is important to ensure that the expert systems are reliable and accurate; consequently, they must be evaluated. We review published experience with expert systems in the telecommunications industry and we propose some principles that we feel could usefully be adopted for their evaluation.     

HypEs: an architecture for hypermedia-enabled expert systems

Expert systems and hypermedia constitute two important technologies for organizations to create, store, and manage information products. The purpose of our research is to develop an architectural blueprint for the construction of hypermedia-enabled expert systems. We propose an architecture termed HypEs (Hypermedia-enabled Expert System) for the development of media-rich expert systems. The integration of hypermedia technologies and expert systems can provide significant potential benefits by enabling the storage and manipulation of non-textual knowledge, enhancing the effectiveness of both knowledge acquisition from the sources of expertise and knowledge transfer to non-expert users. An experimental analysis that contrasts the hypermedia-enabled and text-restricted expert systems provides results that underscore the usefulness of hypermedia techniques in enhancing the effectiveness of expert systems in practical applications.     

CIM system for telecommunications equipment

Much of telecommunications equipment manufacturing consists of relatively small production runs of a wide variety of products. This paper discusses the problems in such manufacturing systems and the development of a computer-integrated manufacturing system proposed to solve these problems.     

Distributed conflict resolution among cooperating expert systems

Abstract: Cooperating experts approach attempts to integrate and coordinate the activities of multiple specialised problem solvers that come together to solve complex tasks such as design, medical diagnosis, business management and so on. Due to the different goals, knowledge and viewpoints of agents, conflicts may arise at any phase of the problem-solving process. Managing diverse expertise requires well-organised models of conflict resolution. In this paper, a model for cooperating experts is described which openly supports multi-agent conflict detection and resolution. The model is based on the idea that each agent has its own conflict knowledge which is separated from its domain level knowledge, and each agent has its own conflict resolution knowledge which is not accessible and known by others. Furthermore, there are no globally known conflict resolution strategies. Each agent involved in a conflict chooses a resolution scheme according to its self interest. The model is described by using an example in the domain of office design and it is compared with other systems.     

A hybrid expert system for equipment failure analysis

This paper outlines the development of a web-based expert system, equipment failure analysis expert system (EFAES), for the largest steel company in Taiwan. The EFAES inference engine employs both case-based reasoning (CBR) and rule-based reasoning (RBR) to generate a hybrid recommendation list for cross validation. Moreover, this inference engine was designed to support a hierarchical multi-attribute structure. Unlike the traditional ‘flat’ attribute structure, this hierarchical multi-attribute structure allows experts to weigh the attributes dynamically. Two two-dimensional matrixes, multi-attribute analysis (MAA) and subattributes matrix (SAM), are used to store the attributes' weight values. Normalized relative spending (NRS) is adapted to normalize the weight values for the inference engine. The system recommends both cases and rules, which can give more information in recognizing the failure types. According to our experimental results, applying our proposed method in an inference engine to analyze failure can result in better quality recommendations.     

Techniques for Bayesian analysis in expert systems

A causal network is frequently used as a representation for qualitative medical knowledge, in which conditional probability tables on appropriate sets of variables form the quantitative part of the accumulated experience. For probabilities temporarily assumed known, we describe efficient algorithms for propagating the effects of multiple items of evidence around multiply-connected networks and hence providing precise probabilistic revision of beliefs concerning the current patient. As a database accumulates we also require the quantitative aspects of the model to be updated, as well as to learn about the qualitative structure, and we suggest some formal statistical tools for these problems.     

A comparative analysis of methods for expert systems

Given the current widespread interest in expert systems, it is important to examine the relative advantages and disadvantages of the various methods used to build them. In this paper we compare three important approaches to building decision aids implemented as expert systems: Bayesian classification, rule-based deduction, and frame-based abduction. Our critical analysis is based on a survey of previous studies comparing different methods used to build expert systems as well as our own collective experience over the last five years. The relative strengths and weaknesses of the different approaches are analysed, and situations in which each method is easy or difficult to use are identified.     

Designing an expert system for fraud detection in private telecommunications networks

Telecommunications fraud not only burdens telecom provider’s accountings but burdens individual users as well. The latter are particularly affected in the case of superimposed fraud where the fraudster uses a legitimate user’s account in parallel with the user. These cases are usually identified after user complaints for excess billing. However, inside the network of a large firm or organization, superimposed fraud may go undetected for some time. The present paper deals with the detection of fraudulent telecom activity inside large organizations’ premises. Focus is given on superimposed fraud detection. The problem is attacked via the construction of an expert system which incorporates both the network administrator’s expert knowledge and knowledge derived from the application of data mining techniques on real world data.     

Scheduling problems in parallel systems for telecommunications

The scheduling of the large number of tasks with various cooperation modes poses interesting theoretical problems in parallel systems used in telecommunications. Such systems are fully distributed ones, preventing coherent observability. In such systems no absolute time-space reference exists. The theoretically optimal set of local references is given as the limiting factor for the incoherent observability. The failures and/or modifications inherent in the massively parallel systems may change their configurations dynamically. Thus no optimal algorithms can be developed for the effective utilization of the resources available in such a system. The influence of the granularity level and of the cooperation modes of the processes on scheduling are investigated in order to identify areas for further study.     

Formula databases for high-performance resolution/paramodulation systems

Over the past 25 years, researchers have written numerous deduction systems based on resolution and paramodulation. Of these systems, very few have been capable of generating and maintaining aformula database containing more than just a few thousand clauses. These few systems were used to explore mechanisms for rapidly extracting limited subsets of relevant clauses. We have developed a simple, powerful deduction system that reflects some of the best of the ideas that have emerged from the research. This paper describes that deduction system and casts the idea in a form that makes them easily accessible to researchers wishing to write their own high-performance systems.This work was partially supported by National Science Foundation grant CCR-8810947 and by the Office of Scientific Computing, U.S. Department of Energy under contract W-31-109-Eng-38.     

Prototypical knowledge for expert systems

Knowledge of situations typically encountered in performing a task is an important and useful source of information for solving that task. This paper presents a system that uses a representation of prototypical knowledge to guide computer consultations, and to focus the application of production rules used to represent inferential knowledge in the domain. The explicit representation of control knowledge for each prototypical situation is also emphasized.     

A proposal for CAD/CAM interface with expert systems

In the computer-integrated manufacturing (CIM) environment, the key technologies, CAD and CAM, should be fully integrated with high operability. It is claimed, however, that CAD and CAM have so far been developed independently. Although much effort has been made to integrate CAD and CAM, this reality is far from completion.

Therefore, to establish a CAD/CAM interface with higher integration, the concept of a computer-aided drafting procedure with expert systems has been proposed on the basis of analysis of the information explicitly and implicity described on the part drawing, and also of the required knowledge of the designer to produce the part drawing. The CAD/CAM interface proposed here is available for producing not only the part drawing but also the process plan for the corresponding part, by effectively utilizing the knowledge of the expert. A prototype CAD/CAM interface deals with axi-symmetrical rotational parts implemented on a workstation.     

Model for knowledge and legal expert systems

This paper presents a four layer model for working with legal knowledge in expert systems. It distinguishes five sources of knowledge. Four contain basic legal knowledge found in published and unpublished sources. The fifth consists of legal metaknowledge. In the model the four basic legal knowledge sources are placed at the lowest level. The metaknowledge is placed at levels above the other four knowledge sources. The assumption is that the knowledge is represented only once. The use of metaknowledge at various levels should make it possible to use the appropriate knowledge for the problem presented to the system. The knowledge has to be represented as closely to the original format as possible for this purpose. Suitable representation formalisms for the various types of knowledge in the five knowledge sources are discussed. It is not possible to indicate a best representation formalism for each knowledge source.     

设备远程监控和网络配置方案

<正> 应用需求对于电信机房监控设备、电视广播设备等行业设备通常具有数量多、分布广、监控信息统一等特点,适合无人监控,以降低运行维护成本。由于设备分布广泛,传统方案管理监控和配置这些设备必须靠本地的监控配置和管理,很不方便,并且维护难度大、成本高。因而电信     

Modeling and analysis of equipment managers in manufacturingexecution systems for semiconductor packaging

Equipment Managers (EMs) play a major role in a Manufacturing Execution System (MES). They serve as the communication bridge between the components of an MES and the equipment. The purpose of this paper is to propose a novel methodology for developing analytical and simulation models for the EM such that the validity and performance of the EM can be evaluated. Domain knowledge and requirements are collected from a real semiconductor packaging factory. By using IDEFO and state diagrams, a static functional model and a dynamic state model of the EM are built. Next, these two models are translated into a Petri net model. This allows qualitative and quantitative analyses of the system. The EM net model is then expanded into the MES net model. Therefore, the performance of an EM in the MES environment can be evaluated. These evaluation results are good references for design and decision making.     

Two techniques of sensitivity and uncertainty analysis of fuzzy expert systems

Problems characterized by qualitative uncertainty described by expert judgments can be addressed by the fuzzy logic modeling paradigm, structured within a so-called fuzzy expert system (FES) to handle and propagate the qualitative, linguistic assessments by the experts. Once constructed, the FES model should be verified to make sure that it represents correctly the experts’ knowledge. For FES verification, typically there is not enough data to support and compare directly the expert- and FES-inferred solutions. Thus, there is the necessity to develop indirect methods for determining whether the expert system model provides a proper representation of the expert knowledge. A possible way to proceed is to examine the importance of the different input factors in determining the output of the FES model and to verify whether it is in agreement with the expert conceptualization of the model. In this view, two sensitivity and uncertainty analysis techniques applicable to generic FES models are proposed in this paper with the objective of providing appropriate tools of verification in support of the experts in the FES design phase. To analyze the insights gained by using the proposed techniques, a case study concerning a FES developed in the field of human reliability analysis has been considered.     

A shell for cooperating expert systems

Abstract: This paper describes a shell for cooperating expert systems that has been developed at the University of Porto. The main goal of this shell is two-fold: to generate a community of cooperative knowledge-based systems and to develop several special reasoning techniques which can be used under a distributed and cooperative paradigm. UPShell is able to convert a set of generated intelligent systems (ISs) into a community of cooperative ISs. In this first version it is already possible to generate different intelligent systems which are able to run 'simultaneously' as separate Unix processes and, using a message-passing mechanism, to communicate among themselves. They can be set to pursue an overall goal in a cooperative way. Moreover, several tasks can be given to each IS to be solved simultaneously, and the IS can switch from task to task according to dynamic priorities reflecting the urgency attached to the specific sub-tasks that emerge. The shell described here may also be used to test, within a distributed environment, some time-bounded reasoning techniques that are presently being developed. The paper has three main parts: a general overview of the UPShell (Section 1); a tutorial explaining, by means of examples, how to use the package (Section 2); and, finally, some considerations on the reasoning techniques used and future improvements (Sections 3–5).     

Building expert systems for repair domains

Abstract: This paper describes a conceptual framework for building expert systems in repair domains. A specific example of the use of this framework in building an expert system for a field service repair problem is given. The example system is designed to assist field service technicians in troubleshooting and repairing electronic systems at the board level. This system, a Field Service Advisor (Fieldserve), is designed (1) to diagnose single or multiple defects in electronic systems, (2) to guide a technician through appropriate repair procedures, (3) to verify diagnoses and monitor repair effectiveness and (4) to maintain records for subsequent evaluation and quality control.     

A structure for expert systems maintenance

An approach to the design of maintainable expert systems is presented. Central to this approach is a conceptual model in which the data and knowledge are both modelled as formal “items” in a uniform way. “Objects” are introduced as “item building” operators. The notion of the “decomposition” of items and objects provides the foundation for a single rule of normalization. This single rule applies to all items and objects, including knowledge items, and is a non-trivial generalization of the traditional normal forms for database. Coupling relationships represent the necessary maintenance paths in the conceptual model. A complete characterization of coupling relationships is given, and the value of normalization to the reduction of maintenance costs is discussed.