Expert system-user integrated adaptive systems

Many expert systems operate in dynamic environments where various pertinent environmental variables and conditions vary with the passage of time. These environmental variables and conditions may affect both the set of conditions applied to input variables of expert systems and the set of recommendations provided by expert systems. For this reason, expert systems developed according to dynamic structure will generate timely recommendations. To incorporate dynamic characteristics into the structure of expert systems, it is necessary to develop expert systems as adaptive systems. This paper intends to integrate concepts of learning and adaptiveness into expert system technology.

Expert systems used to assist loan officers in improving the decision-making process of commercial loans are typical examples of expert systems that operate in dynamic environments. This paper illustrates that the quality of information provided to loan officers by expert systems may be improved when expert systems are designed as adaptive expert systems.     

SOCIAL SYSTEMS THEORY AND PRACTICE: THE NEED FOR A CRITICAL APPROACH

Much of the success of science in explaining, predicting and controlling natural systems can be attributed to the well understood methods that exist for producing and testing theory in the natural sciences. The successful development of social systems science is similarly likely to depend on the elucidation of methods of inquiry suitable to the systems of its concern. Unfortunately the successful methods employed by natural scientists cannot be simply taken over and used in social systems science. Systems scientists who attempt this, risk operating with wholly inappropriate tools when dealing with social systems. Alternative methods of inquiry have been developed in the “soft” systems tradition which are more appropriate for use in relation to one large class of social systems. However, there are many social systems for which even these soft systems approaches are inappropriate. For such social systems there is a need for a more radical and critical approach to producing and verifying social systems science. This paper seeks to demonstrate the need for a critical approach in relation to one class of social systems and shows how only this kind of approach can take account of the special characteristics of this category of social system.     

双线性系统可控性综述

双线性系统是一类特殊的非线性系统,广泛存在于现实世界中,如工程、经济、生物、生态等领域,被认为是最接近于线性系统的非线性系统．对双线性系统的研究已历经了近半个世纪. 作为系统最基本的属性,双线性系统可控性的研究一直以来是热点和难点.本文分别对连续双线性系统可控性和离散双线性系统可控性进行讨论, 综述了双线性系统可控性的研究.特别地,报告了近来对离散双线性系统可控性研究的新成果.最后,例举了一些可控的双线性系统例子.     

可信系统性质的分类和形式化研究综述

计算机系统被应用于各种重要领域,这些系统的失效可能会带来重大灾难.不同应用领域的系统对于可信性具有不同的要求,如何建立高质量的可信计算机系统,是这些领域共同面临的巨大挑战.近年来,具有严格数学基础的形式化方法已经被公认为开发高可靠软硬件系统的有效方法.目标是对形式化方法在不同系统的应用进行不同维度的分类,以更好地支撑可信软硬件系统的设计.首先从系统的特征出发,考虑6种系统特征:顺序系统、反应式系统、并发与通信系统、实时系统、概率随机系统以及混成系统.同时,这些系统又运行在众多应用场景,分别具有各自的需求.考虑4种应用场景:硬件系统、通信协议、信息流以及人工智能系统.对于以上的每个类别,介绍和总结其形式建模、性质描述以及验证方法与工具.这将允许形式化方法的使用者对不同的系统和应用场景,能够更准确地选择恰当的建模、验证技术与工具,帮助设计人员开发更加可靠的系统.     

类广义Lorenz系统的广义同步

应用广义Lorenz标准型研究了包括广义Lorenz系统、双曲型广义Lorenz系统以及Liu-Liu-Liu-Liu系统在内的类广义Lorenz系统的广义同步化问题．利用映射将一大类三阶二次混沌系统变换为广义Lorenz标准型,设计控制器使变换后的系统达到完全同步,进而使变换前的系统实现广义同步．将该方法分别用于拓扑等价和不等价的两个系统,通过数值仿真,发现结果和理论分析相符,从而表明了该方法的有效性．     

Ubiquitous recommender systems

Ubiquitous recommender systems combine characteristics from ubiquitous systems and recommender systems in order to provide personalized recommendations to users in ubiquitous environments. Although not a new research area, ubiquitous recommender systems research has not yet been reviewed and classified in terms of ubiquitous research and recommender systems research, in order to deeply comprehend its nature, characteristics, relevant issues and challenges. It is our belief that ubiquitous recommenders can nowadays take advantage of the progress mobile phone technology has made in identifying items around, as well as utilize the faster wireless connections and the endless capabilities of modern mobile devices in order to provide users with more personalized and context-aware recommendations on location to aid them with their task at hand. This work focuses on ubiquitous recommender systems, while a brief analysis of the two fundamental areas from which they emerged, ubiquitous computing and recommender systems research is also conducted. Related work is provided, followed by a classification schema and a discussion about the correlation of ubiquitous recommenders with classic ubiquitous systems and recommender systems: similarities inevitably exist, however their fundamental differences are crucial. The paper concludes by proposing UbiCARS: a new class of ubiquitous recommender systems that will combine characteristics from ubiquitous systems and context-aware recommender systems in order to utilize multidimensional context modeling techniques not previously met in ubiquitous recommender systems.     

Modeling and Identification of Multirate Systems

Multirate systems are abundant in industry; for example, many soft-sensor design problems are related to modeling, parameter identification, or state estimation involving multirate systems. The study of multirate systems goes back to the early 1950s, and has become an active research area in systems and control. This paper briefly surveys the history of development in the area of multirate systems, and introduces some basic concepts and latest results on multirate systems, including a polynomial transformation technique and the lifting technique as tools for handling multirate systems, lifted state space models, parameter identification of dual-rate systems, how to determine fast single-rate models from dual-rate models and directly from dual-rate data, and a hierarchical identification method for general multirate systems. Finally, some further research topics for multirate systems are given.     

Crisis IT design implications for high risk systems: systems,control and information propositions

The systems view is presented as a complement to the more traditional scientific approach to help reduce and mitigate risk in high risk systems. Implications for this systemic approach are described, principally in the areas of control and information. Most generally, we investigate how high risk systems use information to maintain control, and how IT systems should be designed to support this activity. Two variations in the systems view – the objective and constructive – are distilled and compared, and for each, the implications for crisis IT systems design are discussed. The limitations of the two variations of the systems view are presented, as is a brief annotated bibliography for further reading about the systems view.     

EXPERT SYSTEMS FOR BUSINESS APPLICATIONS

Abstract

Expert systems are becoming more prevalent in financial and business applications. With venture capital pouring into the expert systems area, there is greater interest in expert systems by commercial firms. Companies are either building in-house expert systems capabilities or contracting out to expert system developers to construct expert systems for business applications. This paper presents much of the work being done in developing expert systems in business and discusses fertile areas for constructing more business expert systems.     

使用备份加速RAID5数据重构

对于大部分中小企业,为了保证生产系统所存放数据的安全,通常使用RAID5和备份两种技术.提出了一种新型的RAID5加速重构模型,该模型具有以下优点:1)能够灵活整合生产系统和备份系统;2)充分利用备份系统的资源,加速生产系统内RAID5数据重构;3)改善生产系统服务质量;4)提高生产系统的可靠性和可用性.     

Access cost for asynchronous Byzantine quorum systems

Summary. Quorum systems have been used to implement many coordination problems in distributed systems. In this paper, we study the cost of accessing quorums in asynchronous systems. We formally define the asynchronous access cost of quorum systems and argue that the asynchronous access cost and not the size of a quorum is the right measure of message complexity of protocols using quorums in asynchronous systems. We show that previous quorum systems proposed in the literature have a very high asynchronous access cost. We propose a reformulation of the definition of Byzantine quorum systems that captures the requirement for non-blocking access to quorums in asynchronous systems. We present new Byzantine quorum systems with low asynchronous access cost whose other performance parameters match those of the best Byzantine quorum systems proposed in the literature. In particular, we present a construction for the disjoint failure pattern that outperforms previously proposed systems for that pattern. Received: September 1999 / Accepted: September 2000     

Disconnected general systems

The properties of general systems, so-called disconnectedness, connectedness, and hereditary disconnectedness, are studied. The construction of star sets plays an important role in the study of the following topics: structures of (hereditary) disconnecied systems; equivalent conditions of (hereditary) disconnected systems; equivalent conditions of disconnectedness of quotient systems. Conditions, under which disconnectedness of factor systems can be lifted up to product systems and cartesian product systems, and conditions under which disconnectedness of product systems (cartesian product systems) can predict the disconnectedness of factor systems, are given.     

A comparison of four microcomputer operating systems

This article describes a comparative study of four operating systems for IBM-PC compatible microcomputers. The assessment concentrated on the suitability of the operating systems for use in real-time applications, and on their use as development environments for real-time systems. The study evaluated the predictability and the performance of the operating systems in several areas critical in real-time systems by using comparative benchmarks. In addition, a small-scale simulation of a process control system was developed for each of the systems. The operating systems that were studied were UNIX, OS/2, QNX and FlexOS. These operating systems represent a broad spectrum of systems from general purpose operating systems to small, specialized real-time operating systems. The details of the evaluation process are given and a summary of the results is presented.     

仿射非线性奇异系统的受控分布

研究非线性奇异系统的受控不变分布问题.讨论了非线性奇异系统的受控不变分布算法与该系统经过状态反馈转化为正常非线性系统的受控不变分布算法的关系.得到了在一定条件下,正则非线性奇异系统的受控不变分布算法与该系统经过状态反馈转化为正常非线性系统的受控不变分布算法的一致性.并给出一个例子说明本文的结果.     

动态优先系统及其应用

优先关系是并发系统控制的重要手段,常用于解决并发系统设计中的冲突问题.在有界P/T系统的基础上提出一种动态优先系统,并分别给出它们的交错语义与真并发语义.动态优先系统既可以作为并发与分布式系统的建模工具,也可以作为定义程序设计语言中优先算子的语义基础.最后,基于动态优先系统的概念,为Occam语言扩充了一种动态优先选择算子.     

Towards a taxonomy of intrusion-detection systems

Intrusion-detection systems aim at detecting attacks against computer systems and networks, or against information systems in general, as it is difficult to provide provably secure information systems and maintain them in such a secure state for their entire lifetime and for every utilization. Sometimes, legacy or operational constraints do not even allow a fully secure information system to be realized at all. Therefore, the task of intrusion-detection systems is to monitor the usage of such systems and to detect the apparition of insecure states. They detect attempts and active misuse by legitimate users of the information systems or external parties to abuse their privileges or exploit security vulnerabilities. In this paper, we introduce a taxonomy of intrusion-detection systems that highlights the various aspects of this area. This taxonomy defines families of intrusion-detection systems according to their properties. It is illustrated by numerous examples from past and current projects.     

Challenges for intelligent systems in biology

Biological processes have produced the ultimate intelligent system (humans), and now we are trying to understand biology (and ourselves) by building intelligent systems. Intelligent systems research in biology strives to understand how living systems perform difficult tasks routinely (ranging from molecular phenomena such as protein-folding to organism-level phenomena such as cognition). The definition of intelligent systems in biology can lead to hours of debate. Some say that all high-performance systems that do something difficult with (or to) biological data should be considered intelligent systems. Others insist that the term intelligent system should be reserved for systems using the methods typically associated with modem AI.     

Duality between reachability and observability for adjoint systems

The Kalman duality between the reachability and observability of finite-dimensional linear systems is generalized to adjoint systems (in the sense of Arbib-Manes). The theory includes previous results on infinite-dimensional linear systems and linear systems over rings, and yields new results for classes of nonlinear systems such as bilinear and polynomial systems.     

Reachability analysis of complex planar hybrid systems

Hybrid systems are systems that exhibit both discrete and continuous behavior. Reachability, the question of whether a system in one state can reach some other state, is undecidable for hybrid systems in general. In this paper we are concerned with GSPDIs, 2-dimensional systems generalizing SPDIs (planar hybrid systems based on “simple polygonal differential inclusions”), for which reachability have been shown to be decidable. GSPDIs are useful to approximate 2-dimensional control systems, allowing the verification of safety properties of such systems.