Budgets, Blood, and Turnips

Although the need for new systems (instead of constant maintenance of older systems) is often quite apparent to the MIS department, their advantages are not so readily realized by senior management -which sees only costs and risks instead of benefits. As a result, MIS managers must prove the costs and benefits of such projects. This column examines the difficulty of measuring the costs and benefits of four generations of systems -batch, online, DBMS based, and maintenance motivated - and explains why MIS managers should not only rewrite old systems but turn their attention toward the development of new and innovative systems.     

大数据管理系统的历史、现状与未来

大数据管理技术正在经历以软件为中心到以数据为中心的计算平台的变迁,传统的关系型数据库管理系统无法满足现在以数据为中心的大数据管理的需求,设计新型大数据管理系统迫在眉睫.首先回顾了数据管理技术的发展历史;之后,从大数据管理的存储、数据模型、计算模式、查询引擎等方面分析了大数据管理系统的现状,指出目前大数据管理系统具有模块化和松耦合的特点,并进一步介绍了大数据管理系统应具备的数据特征、系统特征和应用特征,指出大数据管理系统技术还在快速进化之中,预测未来的大数据管理系统应具备多数据模型并存、多计算模式融合、可伸缩调整、新硬件驱动、自适应调优等特点.     

Zero-Dimensional Dynamical Systems, Formal Languages, and Universality

We measure the complexity of dynamical systems on zero-dimensional compact metric spaces by the complexity of formal languages, which these systems generate on clopen partitions of the state space. We show that in the classes of recursive, context-sensitive, context-free, regular, etc., languages there exist universal dynamical systems which yield, by factor maps, all dynamical systems of the class. Universal systems are not unique, but in every class there exists a smallest universal system. Received November 1996, and in final form August 1998.     

Inference, inquiry, evidence censorship, and explanation inconnectionist expert systems

The combination of the techniques of expert systems and neural networks has the potential of producing more powerful systems, for example, expert systems able to learn from experience. In this paper, we address the combinatorial neural model (CNM), a kind of fuzzy neural network able to accommodate in a simple framework the highly desirable property of incremental learning, as well as the usual capabilities of expert systems. We show how an interval-based representation for membership grades makes CNM capable of reasoning with several types of uncertainty: vagueness, ignorance, and relevance commonly found in practical applications. In addition, we show how basic functions of expert systems such as inference, inquiry, censorship of input information, and explanation may be implemented. We also report experimental results of the application of CNM to the problem of deforestation monitoring of the Amazon region using satellite images     

A type-centric framework for specifying heterogeneous, large-scale, component-oriented, architectures

Maintaining integrity and consistency, and effecting conformance in architectures of large-scale systems require specification and enforcement of many different forms of structural constraints. While type systems have proved effective for enforcing structural constraints in programs and data structures, most architectural modeling frameworks include only weak notions of typing or rely on first order logic constraint languages that have steep learning curves associated with them and that become unwieldy when scaling to large systems.We present the Cadena Architecture Language with Meta-modeling (CALM) — that uses multi-level type systems to specify and enforce a variety of architectural constraints relevant to the development of large-scale component-based systems. Cadena is a robust and extensible tool that has been used to specify a number of industrial strength component models and applied in multiple industrial research projects on model-driven development and software product lines.     

On controllability,near-controllability,controllable subspaces,and nearly-controllable subspaces of a class of discrete-time multi-input bilinear systems

This paper considers a class of discrete-time multi-input inhomogeneous bilinear systems. The structure of such systems is most close to linear time-invariant systems’ but they own a strong property. That is, if the systems are uncontrollable, they can still be nearly controllable. Necessary and sufficient conditions for controllability and near-controllability of the systems are established by using a classical decomposition. Furthermore, a geometric characterization is given for the systems such that controllable subspaces and nearly-controllable subspaces are derived and characterized. Similar results on controllability are also obtained for the continuous-time counterparts of the systems. Finally, examples are provided to demonstrate the conceptions and results of this paper.     

Work-arounds, make-work, and kludges

Paradigms are often defined partly in terms of what they are not, or in terms of what they are reacting against. The paradigm of human-centered computing is no exception. We discuss about a user-hostile system. We decided that the terms kludge and work-around, and also the related concept of make-work, has yet to be clearly defined for the intelligent systems community. Human-centered systems are different from user-hostile systems as well as from systems based on a designer-centered approach. We try to clarify the senses of these three terms and suggest ways we might study work-around, make-work, and kludges as an integral part of human-computer systems-rather than as embarrassing necessities that are best swept under the computing research rug.     

DYADIC TIME,DYADIC SYSTEMS,AND EVOLUTION OPERATORS

The aims of this paper are to introduce the notion of dyadic time, to define dyadic systems, as well as to study relations between dyadic systems and their evolution operators, and to clarify the relationship between deterministic and probabilistic systems in terms of their evolution operators.     

Expert Systems: Past, Present, and Future

Expert systems recently have become the object of much attention. Many IS researchers, practitioners, and corporate managers are actively involved in the study and application of these systems. This article places this development in perspective, recognizing that business expert systems have been in existence for more than two decades. It reviews the history of expert systems, discusses their current status, and makes predictions about their future. In addition, the article explores assimilation issues, considers hardware and software, reviews the nature of the applications, and highlights application developers.     

THE PRINCIPLES,PRACTICE, AND PHILOSOPHY OF A SYSTEMS EDUCATON

This paper discusses the principles, practice, and philosophy governing the systems education programs of the Department of Management Systems and Sciences at the University of Hull, UK. These programs promote a pluralist vision of the future development of systems thinking, operationalized through a “>system of systems methodologies,” and guided by the philosophy of critical systems thinking.     

Pattern generation, topology, and non-holonomic systems

We consider the problem of achieving a desired steady-state effect through periodic behavior for a class of control systems with and without drift. The problem of using periodic behavior to achieve set-point regulation for the control systems with drift is directly related to that of achieving unbounded effect for the corresponding driftless control systems. We prove that in both cases, the ability to use periodic behavior, and more generally, bounded behavior, to achieve the desired goal implies, under a certain topological condition, the non-holonomicity of the control systems. We also prove that under a regularity condition, the resulting system trajectories must be area-generating in a precise sense.     

Overlapping decompositions, expansions, contractions, and stabilityof hybrid systems

Inclusion and extension principles are defined and studied for hybrid systems. The controller design problem for hybrid systems is then considered within the framework of the extension principle. It is shown that if the extension principle is used, then any controller designed in the expanded spaces is contractible to the original spaces for implementation. The stability of hybrid systems is also considered. A number of definitions of stability for hybrid systems are given and it is shown that if a system, which includes another system, is stable, then the included system is also stable. Furthermore, it is shown that, if a controller designed for the expanded system achieves stability, then the contracted controller also achieves stability for the original system. Decentralized controller design with overlapping decompositions is also discussed within the framework of extension. An example is provided to illustrate the proposed approach     

Dissipativity, stabilization, and regulation of cascade-connected systems

This paper presents a technical framework utilizing the dissipativity mechanism that gives rise to the solution of the global regulation problem of the cascade-connected systems subject to both dynamic uncertainty and static uncertainty without knowing the bound of the static uncertainty. Additionally, this paper shows that the nonlinear robust servomechanism problem for the lower triangular systems can be cast into the regulation problem for the cascade-connected systems, thus leading to a complete solution of the nonlinear robust servomechanism problem for the lower triangular systems for the most general case where both the uncertain parameters and the exogenous signals can be arbitrarily large.     

传感器故障检测、分离与恢复的神经网络方法

传感器是测控系统不可缺少的部件,传感器数据的高可靠性是系统正常工作的重要保证,本文基于递归神经网络具有优良的动态系统建模能力和时间数据序列预报区能力,融合时空信息,构造出具有传感器故障检测,分离和故障恢复能力的智能传感器系统,理论 仿真结果表明,所研究系统的优良性能。     

无源性、稳定性和最优性

本文考察仿射非线性控制系统的无源性、稳定性的最优性，以及这三者之间的关系，为分析稳定性，首先研究非线性控制系统和其线性近似的无源性之间的关系。然后指出，就仿射非线性控制系统而言，无源性、稳定性和最优性在某种意义下是反馈等价的。最后讨论了带量测输出的非线性系统的无源性、稳定性和最优性三者之间的关系。     

Multi-agent role allocation: issues,approaches, and multiple perspectives

In cooperative multi-agent systems, roles are used as a design concept when creating large systems, they are known to facilitate specialization of agents, and they can help to reduce interference in multi-robot domains. The types of tasks that the agents are asked to solve and the communicative capabilities of the agents significantly affect the way roles are used in cooperative multi-agent systems. Along with a discussion of these issues about roles in multi-agent systems, this article compares computational models of the role allocation problem, presents the notion of explicitly versus implicitly defined roles, gives a survey of the methods used to approach role allocation problems, and concludes with a list of open research questions related to roles in multi-agent systems.     

Information Systems Knowledge: Foundations, Definitions, and Applications

A key component of research within information systems is the use of valid instruments to measure numerous aspects of technology, organizations, and people. Validated instruments exist for many different variables and more are available all the time. Knowledge of a particular domain is an integral part of working competently, effectively, and successfully within that domain (N.M. Degele, World Futures, 50, 743–755, 1997). Therefore, this paper will describe the rationale for the development of an instrument to measure the information systems knowledge of individuals. This rationale is rooted in several streams of research, such as absorptive capacity and certainty of knowledge, and focuses on three main questions: why measure knowledge of information systems, how to measure this knowledge, and what to actually measure. The definitions of knowledge and information systems knowledge are developed and refined through an analysis of the literature covering the philosophical, psychological, and educational aspects of knowledge. The resulting models of knowledge and specifically information systems knowledge are then applied to research streams within the information systems discipline as well as practitioner-oriented needs.