Optimization of I/O systems by cache disks and file migration: A summary

The file system, and the components of the computer system associated with it (disks, drums, channels, mass storage, tapes and tape drives, controllers, I/O drivers, etc.) comprise a very substantial fraction of most computer systems; substantial in several aspects, including amount of operating system code, expense for components, physical size and effect on performance. In a companion paper, we surveyed the traditional methods for optimizing the I/O system. We then examined disk and I/O system architecture in IBM type systems, and indicated shortcomings and future directions. In this paper we go one step further and summarize research by the author on two topics: cache disks and file migration. Cache disks are disks which have an associated cache which buffers recently used tracks of data. The case for cache disks is presented, and some of the issues are discussed. Parameter values for some aspects of the cache design are suggested. The second part of this paper summarizes the author's work on file migration, by which files are migrated between disk and mass storage as needed in order to effectively maintain on-line a much larger amount of information than the disks can hold. Some of the algorithms investigated are discussed, and the basic results are presented.     

Decision support for manufacturing management

Historically, information systems have been used to improve efficiency through such means as clerical automation, inventory status reporting and transactional processing systems. Today, however, to reduce costs, increase return on investments, and achieve competitive advantage, businesses need to have information systems that support managerial decision-making and result in improved effectiveness. To meet this requirement, new approaches are needed in order to define the right problem and work the problem right. By using such techniques as critical success factor analysis followed by a top down system development approach, developing systems through prototyping and using end-user oriented software, these needs can be met.This article describes several company experiences of using a management systems planning and development process. This process in one company presented an opportunity to test the feasibility of developing an alignment between business goals and events critical to the success of the business. Management believed that to succeed in the future they must be forward thinking in their identification and use of information systems to improve managerial effectiveness. Their questions were “What should we do?” and “How should we do it?” By applying these techniques they were able to achieve outstanding results in a very short period of time.     

Stabilization of polynomially parametrized families of linear systems. The single-input case

Given a continuous-time family of finite-dimensional single-input linear systems, parametrized polynomially, such that each of the systems in the family is controllable, there exists a polynomially parametrized control law making each of the systems in the family stable.     

高效分子排阻色谱法测定化学驱油体系中的部分水解聚丙烯酰胺

介绍了用分子排阻色谱技术定量测定化学驱油体系中的部分水解聚丙烯酰胺（ＰＩＩＰＡ）的方法。该方法以ＳＩ－２００二羟基键合相为固定相，以甲醇／０．０５ｍｏｌ／ｌ的ＮａＩＩ２ＰＯ４（体比４０／６０）为流动相，使用ＵＶ检测器在２１３ｎｍ处检测。表面活性剂／聚合物驱油液中所有组分对ＰＩＩＰＡ的测定均无干扰。吸附试验证明测定可靠性好。最低检测浓度为１μｇ／ｍｌ。回收率为９７．３％－１００．５％。     

Negotiating temporal orders

This paper focuses on time management as a cooperative task. Based on an analysis of the cultural complexity of scheduling surgical operations in a large clinic, possibilities of using information technology are explored. A computer system can be used to facilitate and change the negotiation of resource deployment in complex organizations by a) providing an integrated view of time management problems and decision-making within a complex organization, and b) by improving coordination. The paper discusses some design options for such a system which combines negotiation support with an auromatic sheduling device and critically examines the rationale for an organization to accept and implement such a system.     

From Interfaces for Application Portability (IAP) to Open System Environment profiles (OSE)

The ISO/IEC JTC 1 Technical Study Group 1's report on Interfaces for Application Portability has initiated a worldwide attempt at specifying a Reference Model for Open System Environments. This article provides a concise but comprehensive view of the current State of the Art and emphasizes the interaction with the ‘user’ of such a Reference Model.     

State-feedback control of systems with multiplicative noise via linear matrix inequalities

We consider LTI systems perturbed by parametric uncertainties, modeled as white noise disturbances. We show how to maximize, via state-feedback control, the smallest norm of the noise intensity vector producing instability in the mean square sense, using convex optimization over linear matrix inequalities. We also show how to maximize performance robustness, where performance is measured by expected output energy, with either bounded initial conditions and zero inputs (classical LQG cost), or zero initial conditions and deterministic inputs of bounded energy (a generalization of the H_∞ norm).     

Working relations of technology production and use

This paper explores the relevance of recent feminist reconstructions of objectivity for the development of alternative visions of technology production and use. I take as my starting place the working relations that make up the design and use of technical systems. Working relations are understood as networks or webs of connections that sustain the visible and invisible work required to construct coherent technologies and put them into use. I outline the boundaries that characterize current relations of development and use, and the boundary crossings required to transform them. Three contrasting premises for design-the view from nowhere, detached engagement, and located accountability — are taken to represent incommensurate alternatives for a politics of professional design. From the position of located accountability, I close by sketching aspects of what a feminist politics and associated practices of system development could be.I am deeply grateful to Phil Agre, Jeanette Blomberg, Andrew Clement, Mike Hales, Susan Newman, Leigh Star, Randy Trigg, and Ina Wagner for their careful readings and critical suggestions on earlier versions of this paper.     

Production planning and control: A personal philosophy

This paper looks at the author's beliefs, concerning the ways in which Production Planning and Control should be developed in the future. He sees the way forward as one which includes small factories - even if the companies are large - less specialisation; simple materials flow systems; Flexible programming; PBC or Kanban and the development of systems theory.     

Logic-based formula management strategies in an actuarial consulting system

In many decision support systems, multiple decision methods and models must be combined for solving a complex problem. Expertise is required for selecting, adapting and coordinating appropriate models. This paper describes the design and implementation of a knowledge-based model management system called the Actuarial Consulting System (ACS). The ACS supports actuaries in making pricing decisions in the domain of life insurance. Actuarial knowledge is organized using a graph formalism called Formula Derivation Network (FDN), represented in Prolog as a hierarchy of predicates. On the user level, a Problem Analyzer converts a problem specification by the user into a search problem on the stored collection of FDNs. Using different search strategies, including human expert rules, the Surface Planner generates an efficient solution strategy (sequence of models). At the lowest level, a Plan Executor retrieves or requests model data and issues appropriate function calls to a subroutine library.