bluuebunny/crossref_metadata_2025 huggingface dataset:
Institutional and ad hoc DSS and their effective use
Authors: Donovan John J. , Madnick Stuart E.
Published: October 2004

The term decision support system (DSS) applies to the subset of management information systems that truly support decision-making processes. This term excludes structured decision systems that essentially present the appropriate decisions for management approval, as is the case in many inventory-control or billing systems. This paper differentiates between two classes of decision support systems: institutional DSS, which deal with decisions of a recurring nature, and ad hoc DSS, which deal with specific problems that are usually not anticipated or recurring. An understanding of these two classes of decision support systems facilitates making explicit both their common and different computational needs. This analysis has provided a basis for the development of computational facilities to support effectively their common needs. This paper briefly describes some of those computational facilities and illustrates their use in systems (institutional and ad hoc) which are being effectively used to support regional energy decisions in New England.
An information presentation system for decision makers
Authors: Yonke Martin D. , Greenfeld Norton R.
Published: October 2004

This paper describes a new concept for interfacing operational decision makers with their information systems. It is intended to overcome the rigidities of current architectures by enabling the decision maker to direct, modify, and manipulate the presentation of information in real-time through a highly automated interface system. The current practice of specifying a decision maker's desires to a programmer, who must in turn produce a data gathering and formatting program that interfaces with some graphics system, is unsatisfactory for the real-time needs of an ever-changing decision environment.An experimental Information Presentation System has been implemented utilizing a high-level knowledge representation language. The system manipulates general descriptions of information presentation concepts such as coordinate systems, trnasformations, display regions, display objects, and the relationships between data objects and their depictions. This paper summarizes the current state of that system and the Information Presentation System concept.
Graphical problem solving in DSS
Authors: Jacob Jean-Paul , Sprague Ralph H.
Published: October 2004

New hardware and software to support conversational graphics provide a more natural interface between a decision-maker and his/her data/model. They also permit and facilitate the use of new algorithms that exploit the ability of humans to recognize patterns and process two-dimensional data structures (pictures). These capabilities are becoming a major part of the value of Decision Support Systems.
Application of a DSS architecture to a special-purpose interactive language
Authors: Crabb Earl
Published: October 2004

Linking part of a functioning graphics oriented DSS with a host machine running on an existing special purpose interactive language can save implementation costs and implementation time for financial and marketing modelers. We assume that the DSS includes a color raster display device with an extended terminal support system, a joystick, a keyboard, and relational database software. The host machine is assumed to be an IBM 370 running a VM/CMS operating system and an applications program which is a commercially available financial and marketing modeling language known as EXPRESS. Many of the components typically contained in a DSS are already available in EXPRESS, including all relevant applications routines, database support routines, and databases containing relevant financial data. The paper outlines a potential dialogue section of a DSS, and its communications with the host. We explore a logical method of connecting the old concept of a command oriented interactive language with the new DSS concepts, in the specific limited area of financial and marketing modeling.
Technology, methodology & information systems
Authors: Welke R. J. , Konsynski B. R.
Published: October 2004

A brief examination is made of the relationship of information system, design methodologies, and associated information processing technology. Historical perspectives are highlighted. The data processing systems is first examined from the standpoint of the application of technology. Areas of data management, centralization and distribution, data integrity and controls, cost-capacity progress, and applications software development are reviewed. The user system is next considered as a locus of a large complement of current research activities. The perspectives related to the user role in system development and the evaluation criteria in the design and development process are addressed. Finally, development and operating methodologies are considered as an important dimension of the information systems impact in organizations. The methodological views and development procedure approaches are presented as critical factors impacting the evolution of information systems in organizations.
Office procedures as a distributed database application
Authors: Lin Wente K. , Ries Daniel R. , Blaustein Barbara T. , Chilenskas R. Mark
Published: October 2004

An office proedure specification system is described. The system is to be implemented as a database application in a distributed database management system being developed at Computer Corporation of America. Because of its data-base application characteristic, the system treats form copying and routing differently from other office information systems. This differences makes controlling and tracing forms easier than it is in other systems. We also introduce a generalized trigger, called trigger-lock, for synchronizing independently created procedures and for exception handling.
Determining an organization's information requirements
Authors: Yadav Surya B.
Published: October 2004

The issue of information requirements of an organization and their specifications span two isolated territories. One territory is that of organization and management and the other belongs to technicians. There is a considerable gap between these two territories. Research in requirements engineering (technician's side) has primarily concentrated on designing and developing formal languages to document and analyze user requirements, once they have been determined. This research has ignored the organizational issues involved in information requirements determination. Research in the field of organization and management has addressed the organizational issues which affect information requirements of an organization. Various frameworks reported in the literature provide insights, but they cannot be considered as methods of determining requirements. Little work has been done on the process of determining requirements. This process must start with the understanding of an organization and end with a formal specification of information requirements. Here, it is worth emphasizing the fact that the process of determining and specifying information requirements of an organization is very different from the process of specifying design requirements of an information system. Therefore, program design methodologies, which are helpful in designing a system are not suitable for the process of determining and specifying information requirements of an organization.This paper discusses the state of the art in information requirements determination methodologies. Excluded are those methodologies which emphasize system design and have little to offer for requirements determination of an organization.
Automating database construction
Authors: Spiegler Israel
Published: October 2004

This paper introduces a methodology for automating database construction in which Problem Statement Language (PSL) statements are translated into Data Definition Language (DDL) statements of a Data Base Management System (DBMS). These two commercially available software tools, when linked together, encompass the database construction life cycle from requirement specification to implementation of a target database system via the DBMS software.
Database dynamics
Authors: Rolland Colette
Published: October 2004

This paper argues for a global description, at a conceptual level, of the structure and the behavior of data, and an automatic control of the flow of data in the course of time.It presents an original model to integrate at the conceptual level, data, processes and dynamics in the design of information systems and a set of mechanisms integrated in a processor which provides the synchronized updating of the database.
Information systems strategy and end-user application development
Authors: Sumner Mary , Klepper Robert
Published: October 2004

End-user computing in organizations with different information systems strategies was studied to determine the nature and characteristics of user-developed applications, systems development practices, quality assurance methods, and policies and procedures for end-user development. The findings showed that the information systems strategies of the firms studied did not markedly affect end-user computing activities. In most of these firms, strategic end-user systems were being designed by functional specialists, suggesting their role as catalysts for introducing strategic uses of information technology in user departments in which computing had been primarily valuable for operational efficiency in the past. Formal systems development practices such as data validation, documentation, and data security were not being followed, indicating a need for user training. Although policies and procedures for hardware and software acquisition were in effect, users were largely unaware of policies or guidelines addressing application development issues.
Predicting readability of data processing written materials
Authors: Guillemette Ronald A.
Published: October 2004

Poorly written documentation adversely affects the acquisition, development, use, maintenance, management and control of application software. Readability formulas, comprised of certain linguistic variables, provide rough estimates of the potential difficulty of reading material. This paper illustrates the application of well-known readability formulas in a readability assessment of the 1985 ANSI COBOL Standard. The paper summarizes certain limitations of readability formulas and concludes with suggestions concerning the use of readability formulas in the evaluation of computer-related material.
Scientific progress of management information systems
Authors: Farhoomand Ali F.
Published: October 2004

The objective of this paper is to explore the historical progress of management information systems (MIS) from a philosophic scientific perspective. The study is based on the thematic analysis of research strategies of 536 articles published during the period 1977-1985. The results of this survey indicate that MIS has been undergoing significant shifts in terms of the research strategies employed by researchers. More specifically, there has been a shift from non-empirical research to empirical studies over the past nine years. However, it seems that in spite of recent progress in the demarcation of its boundaries, MIS has not made very significant progress as a scientific discipline. The paper takes the position that this state of the arts will not change until MIS develops a body of substantive theories specific to its domain.
Building and implementing an information architecture
Authors: Brancheau James C. , Schuster Larry , March Salvatore T.
Published: October 2004

An information architecture is a personnel, organization, and technology independent profile of the major information categories used within an organization. It provides a way to map information needs, relate them to specific business functions, and document their interrelationships. It is used to guide applications development and facilitate integration and sharing of data. This paper describes an approach for developing a corporate/global information architecture. It also describes how the information architecture can be used to guide new systems development efforts. Experience at Pillsbury U. S. Foods is used to illustrate the concepts involved. While the process used at Pillsbury necessarily reflects the unique combination of circumstances present within that organization, it also reflects the basic requirements for developing and implementing an information architecture in any large organization.
Corporate MIS/DP and end user computing
Authors: Kwan Stephen K. , Curley Kathleen Foley
Published: October 2004

A survey of MIS professionals and end users in corporations is used to develop an understanding of the impact of End User Computing on the corporate information processing environment. Traditional corporate MIS department's role and degree of involvement in the initiation and development of End User Computing in the corporation is investigated. The study chronicles the evolution of EUC activities in the respondents' organizations and identifies the emergence of a new partnership between the MIS department and end users based on a set of redefined roles, responsibilities and relationships. These changing roles and responsibilities are described and discussed.
Shared variables
Authors: Elsom Ken
Published: October 2004

This is a summary of the discussions which took place in the session on the sharing of variables in Ada 9X.
Object-oriented mechanisms
Authors: Atkinson Colin
Published: October 2004

Three groups of requirements were considered in this session:

Object-Oriented Programming - or more specifically, the mechanisms of inheritance and polymorphism.

General References

Finalisation

Experience of object-oriented programming amongst the majority of delegates was fairly limited, so rather than attempt to assess the value of object-oriented mechanisms in themselves attention was focussed on their potential impact on the real-time requirements. The session began with a brief introduction of the requirements, and of the possible strategies for satisfying them in Ada 9X, followed by a general discussion.
Dynamic priorities, priority scheduling and priority inheritance
Authors: Maymir-Ducharme Fred
Published: October 2004

Scheduling requirements are a major portion of the set of requirements that must be addressed by the Ada 9X Project. This is evident by the numerous Revision Requests (RRs) submitted (over 25) to the Ada 9X Project Office and the subsequent Revision Issues (RI-7005 and RI-7007). The related 9X requirements are:

R1 - Flexible scheduling

R2 - Flexible entry queue ordering

IR2 - Rendezvous performance

IR3 - Extended priority support

WR1 - Flexible select algorithm

This report summarizes the workshop's discussions on this important area. The discussions first considered dynamic priorities, and then priority scheduling and priority inheritance.
Asynchronous transfer of control and interrupt handling
Authors: Quiggle Thomas J.
Published: October 2004

This is a summary of the discussions on two requirement areas:

Asynchronous Transfer of Control

Interrupt Handling
A performance standard for Ada 9X
Authors: Burns A.
Published: October 2004

Real-time systems have special performance requirements that are often impossible to satisfy utilizing only general purpose Ada compilation and run-time environments. It is proposed that a secondary Performance Standard be produced which explains and documents the programming paradigms used by real-time practitioners, and the language structures amenable to effective optimization. It is argued that a Catalogue of authorized scheduling models should also be part of this secondary standard.
Distributed communications
Authors: Kamrad M. , Cross J.
Published: October 2004

Communications among multiple Ada programs is a must, either as an explicit link or as an invisible link hidden beneath a distributed Ada veneer. Unisys has defined two Ada package specifications for inter-program communications, that are derived from the requirements developed at the Third International Workshop on Real-Time Ada Issues (RTAW3). Unisys is implementing these packages on several embedded real-time testbeds, both as standalone capabilities for application developers and as the communication layer supporting a distributed Ada system. These specifications are proposed as a basis for a secondary standard for inter-program communication for Ada9X.

This paper describes how these specifications match the RTAW3 requirements and the motivation for their features. Some details of the specifications are interspersed throughout the text, with a full specification contained in the appendix.
Adapting Ada distribution and fault tolerance
Authors: Gargaro A. B. , Goldsack S. J. , Powers R. K. , Volz R. A. , Wellings A. J.
Published: October 2004

During the Third International Real Time Ada Workshop held at Nemacolin Woodlands, Pennsylvania, in June 1989, the present authors formed a study group to review the changes in the Ada standard which would make the language more suitable for programming distributed systems. It was accepted that one of the important advantages of distributing embedded systems was the potential for recovery from partial failure of hardware, and that the techniques of programming recovery from such failure were not well supported by the current form of Ada. The working group made specific proposals, which have since been refined at a further meeting and discussions by electronic mail. The present paper reviews the causes of difficulty, and then outlines the new proposals, explaining their rationale in relation to the identified requirements.
Problems with Pthreads and Ada
Authors: Pazy Offer
Published: October 2004

This position paper discusses issues related to the recent effort to add real-time extensions to the posix (1003.1 |3|) standard, and in particular to the proposal for light-weight tasking in the form of pthreads |2|. It is claimed that this effort is relevant to the Ada community, especially in the real-time domain. While offering great opportunities to improve the performance of multi-tasking, real-time Ada applications, it may become not useful if the semantics of the specifications are not thought about very carefully, and the match with Ada requirements is not satisfied. Due to certain problems with the proposal as it stands now, it is suggested that the workshop take a close look at the draft, evaluate it, and decide on a plan of action to guarantee the suitability of pthreads to real-time Ada applications before it is approved as a standard.
Efficient periodic execution of Ada tasks
Authors: Quiggle Thomas J.
Published: October 2004

The Ada language has been faulted for not providing an efficient and reliable mechanism to support periodic execution of tasks. Formulations that rely on delay statements in each periodic task or on user-supplied dispatcher tasks are unreliable or inefficient. This paper presents a simple model based on periodic pseudo-interrupts. This model can be efficiently implemented within the confines of the 1983 Ada language standard.
Virtual terminal protocols transport service and session control
Authors: Jacobsen Tom , Høgh Per , Hansen Inger Marie Toft
Published: October 2004

The methods to identify the different terminal protocols for EURONET and the parameter selection mechanism in VPT-D, particularly the terminal mode, are discussed. Based on this, the problems concerning protocol shift are investigated. An integrated solution is outlined and the ISO Reference Model of Open Systems Interconnection is enhanced.
Basic elements of a network data link control procedure (NDLC)
Authors: Pouzin L.
Published: October 2004

Existing transmission procedures have been devised to control transmission over wire-like channels, since it was the only widely available medium, usually telephone lines. New proposals discussed in ECMA or ISO are somehow ambiguous, as they give no hint as to which transmission medium is assumed. In fact, the proposed schemes assume a wire-like medium, although this is not mentioned.

New technologies, such as satellite links, or packet switching, present somewhat different characteristics, which are not taken into account in the present proposals for standardization. Since these technologies are on the verge of commercial applications, it seems desirable to investigate whether their specific requirements can be reasonably met by future standards. If it were not, then other standards would become necessary. On the other hand, it seems that procedures applicable to packet switching networks links are also satisfactory when used over wirelike links. Then it would make sense not to miss the opportunity to work out a single set of standards.

The present paper examines some characteristics of new transmission technologies, and puts forth some proposals.
A restructuring of X25 into HDLC
Authors: Pouzin Louis
Published: October 2004

A major achievement of the standardization process has been the definition of a universal circuit interface (X21 or X21 bis) together with a universal transmission procedure (HDLC). This allows a large degree of compatibility between terminal equipments, regardless of configuration or communication media.

X25 departs from this approach as it requires specialized DTE's that could no longer operate in conjunction with other simple DTE's using an HDLC interface. DTE's and procedures operating on private or public circuits would not be able to communicate with DTE's operating on public virtual circuits. This situation would be chaotic and detrimental to the user interest.

Simple DTE's with single access have no need for an X25 interface. They can certainly establish a call using the X21 or X21 bis interface, and operate in packet mode with an HDLC procedure. In particular, DTE's operating in half-duplex mode, or in a multipoint configuration, cannot use X25.

An analysis of X25 shows that its packet level is redundant with other level. Its functions could be performed in taking advantage of the facilities already present in HDLC. On the other hand X25 contains undesirable functions which should be eliminated or made user options, as they are generating incompatibilities.

The proposal described in this paper has major advantages over the present X25 in providing compatibility between "real" and "virtual" circuits while using a standard HDLC interface for all DTE's.
The role and nature of a virtual terminal
Authors: Barber D. L. A.
Published: October 2004

Recently there has been a growing activity directed towards the definition of standards to facilitate the handling of a variety of terminals in a data network. The Virtual Terminal approach, favoured for some research networks, can seem an over-complex solution unless the proposals are seen in the wider context of a general method for information exchange between computer systems. This note examines the principles underlying the Virtual Terminal, and tries to indicate the merit of this approach. The ideas described are not new; a few are so obvious as to be common knowledge, some come from early work on standards internal to particular computer systems, and the remainder appear in current working papers circulating in EIN, Euronet, IFIP/INWG, and in the literature (see list of references). For this reason, no attempt is made to give a detailed description of any particular Virtual Terminal specification.
Protocols for intelligent terminals
Authors: Barber D. L. A.
Published: October 2004

For some time now most people associated with research computer networks have championed the concept of layered protocols. These are uniform rules of procedure that are intended to be obeyed by each of the different computer systems, connected by a network, in order to disguise their differences and so allow them to intercommunicate freely with each other. The concept is an attractive one and has now been taken up in various standards bodies with a view to agreeing standards for 'open networking' through the public data networks. In principle, if a suitable set of standards can be agreed, any computer system will be able to call any other one and interact with it to conduct a variety of transactions. however, the extent to which this will be true in practice has yet to be established.

The layered protocol approach has proved very effective at the lower levels, but could become cumbersome if it is pushed too far. If this happens, and clumsy standards emerge, large software packages will be required to implement them in each of the cooperating computers. Such packages will be more complex than is desirable for many of the simpler applications, and will add unnecessarily to operational overheads in the smaller systems. This note suggests an alternative approach that seems worthy of consideration in the light of recent advances in micro-electronics and the likely requirements of future systems.

In particular, for intelligent terminals with only one user active there will be less need for the multi-threaded protocols of today, but a greater emphasis must be given to simplicity, so that implementation and subsequent maintenance will be easy and cheap. Accordingly, free-form protocols are introduced, and advocated as a means of harnessing the intelligence of terminals together with the intelligence of their users to greater effect than has hitherto been common.
Computer communication standards
Authors: Chapin A. Lyman
Published: October 2004

This is one of a series of reports on the state of affairs in the communication standards arena. The development of high-quality standards for networking services, protocols, and interfaces has taken on a new urgency in the past few years with the rapid evolution of communication technologies and system architectures that are uniquely suited, both technically and economically, to the construction of distributed application environments. Unfortunately, despite the growing importance of these standards to a very large community of computer system builders and users, the standards-making process is not widely understood; it has a language of its own, and its metabolism is extremely confusing to those who are not actively involved. These reports are motivated by the belief that better standards - timelier, more relevant, and closer to the state of the art - will result from a more widely informed community of interest.

Communication standards are produced by a large number of domestic and international organizations, most of which have meaningless, unpronounceable names that look like something out of the Dewey Decimal system. As a further complication, the organizations and their relationships to one another change as the standards-making process evolves. The most important telecommunications standards organization, the International Telephone and Telegraph Consultative Committee (CCITT), disbands its study groups every four years, holds a plenary meeting (the 8th CCITT Plenary Assembly was held on October 8-19, 1984), and creates new study groups for the next four-year period. The other major communications standards body, Technical Committee 97 of the International Organization for Standardization (ISO), has just completed a major reorganization of its subcommittees, which particularly affects the groups working on Open Systems Interconnection (OSI) standards. This report contains a new ISO TC97 organization chart, which supercedes the corresponding chart in the first of these reports (CCR 13:1, January, 1983). A new CCITT organization chart will appear in the next issue of CCR.

Summary descriptions of what some of the standards groups are doing, arranged by subject, begin below. Needless to say, there are many other standards activities that for reasons of limited space are not mentioned.
Problems in the design of control procedures for computer networks
Authors: Opderbeck Holger
Published: October 2004

This paper is one in a series of short papers highlighting research problems in the area of computer communication. Two previous papers have described problems in the design of data communication networks [CHOU 74] and selected research areas in computer communication [KLEI 74a]. In this paper, we will concentrate on problems which arise in the design of control procedures for computer networks. While some of the problems we are going to describe refer explicitly to packet - switched computer communication networks, others apply to packet-switched as well as line-switched systems. We will consider the following six problems:

1. Flow control and routing

2. Design and implementation of efficient protocols

3. Definition of network performance

4. Portability of communications software

5. Distribution of intelligence

6. Process synchronization with unrealiable components
The CCITT studies packet switching as part of public data network development
Authors: Bothner H.
Published: October 2004

One main body within the UN affiliated International Telecommunications Organisation is the "Comite consultatif international télégraphique et téléphonique" or the CCITT to the whole of the telecommunications world. This grand committee meet in plenary about every four years to adopt recommendations in the areas of tariffs, operations and technical principles, to ensure and improve international telecommunications services between the many networks of all the countries in the world. The committee also decides the questions to be considered in the following study period.

The recommendations of the CCITT has very strong standing internationally, and to a large extent they are being used also as guidelines for national network development. In the field of data transmission the well established cooperation with bodies representing computer users and manufacturers has made it possible to develop widely recognized interface specifications between telecommunications/computing equipment and functions.

Between the plenary meetings of the CCITT the detailed work is being carried out in a number of Study Groups. There is one special group for data transmission techniques over the existing telegraph and telephone networks "SG Special A" (they make all the modem specifications), and one younger one for new digital data transmission networks, the "SG VII". Members of these study groupes are the telecommunications administrations and operating companies ("carriers"), manufacturers of equipment and cooperating international organisations. These groups meet once or twice a year.
The work of IFIP working group 6.1
Authors: Curran Alex , Cerf Vinton
Published: October 2004

IFIP is a multinational federation of professional-technical societies concerned with information processing. At present, thirty-five national societies are members of the federation, united to achieve the following aims:

-to promote information science and technology;

-to advance information cooperation in the field of information processing;

-to stimulate research, development, and application of information processing in science and human activity;

-to further the dissemination and exchange of information about information processing; and

-to encourage education in information processing

Thus, IFIP is both a catalyst and a focal point for conceptual and technological developments which advance the state of the information processing art.

Within IFIP, the technical work is sponsored by a series of technical committees. Under their auspices, workshops, seminars, and conferences are organized to encourage research and technological progress, and to publish definitive texts on the state of that progress. At present, technical committees are working in such fields as:

-information processing terminology

-programming languages

-applications in education

-information processing in medicine

-applications in technology

-data communications

-modelling and optimization

-the effect of information processing on human institutions

In addition to the specialized events organized by the technical committees, IFIP sponsors a Congress once every three years which provides an overall view of the state of information processing science. The next Congress will be held in Toronto, Canada in August 1977.

The library of books published by IFIP now contains sixty volumes. They cover a variety of fields including applications in technology, administration and management, the description and use of programming languages, mathematical theory, computing education, applications in medicine and other human activities, terminology, and overview descriptions of the technological state of the art. Together they constitute a definitive view of research and applications for use by scientists, users, and associated organizations.

Cooperation with CCITT (Commite Consultatif International pour Telephonie et Telegraphic -- a technical body of the International Telegraphics Union which makes recommendations for worldwide standards in the area of telecommunications) has been instituted by the IFIP Technical Committee studying Data Communications. One of the specialized working groups of TC6 coordinates research to clarify the problems and options for the international interconnection of packet switched networks. Results of this research are made available to Study Group VII of CCITT which is deliberating on the facilities and appropriate standards for new data networks (of which packet switched networks are only one type).
Knowledge-based systems for idea processing support
Authors: Young Lawrence F.
Published: October 2004

Knowledge-based systems methods have been seen as means of enhancing the nature of support provided by Decision Support Systems. This paper examines how they can be similarly used to provide user guidance and to represent forms of knowledge that are relevant to the newer type of qualitative support systems called Idea Processing. Basic concepts of Idea Processing and Knowledge-based systems are summarized. The paper identifies several modes of knowledge representation appropriate for particular functions of Idea Processing.
Design of charging mechanisms according to the interaction between information technology type and diffusion lifecycle phase
Authors: Pliskin Nava , Romm Tsilia
Published: October 2004

The prescriptive literature on charging for information technologies considers two main objectives that are served by access charges and use charges: cost recovery and regulation of computing resource utilization. Recently, researchers in the field have suggested that designers of charging mechanisms must also pay attention to the type of information technology and to the phase of the diffusion lifecycle. Specifically, innovation-oriented organizations have been advised to design liberal low charges either for communication technologies or during the technology initiation phase.The contribution of this paper is twofold. First, it organizes published recommendations under one conceptual framework, whereby charging is adapted according to both the technology type and the phase of the diffusion lifecycle. Second, where diffusion patterns are most sensitive to the charging policy, i.e., for communication technologies during the initiation and perhaps even the adaptation phase of the lifecycle, we go beyond existing recommendations and advocate negative charging. Mini-cases serve to illustrate the various recommended charging options.
Microcomputer training users?
Authors: George Joey F. , Theis James W.
Published: October 2004

The literature on computing in organizations assumes that users must be trained to get the most out of using their machines. The natural implication of this assumption is that trained users would differ markedly from non-trained users. Yet in exploratory survey research conducted in a large Southern California company, trained and non-trained microcomputer users did not differ along most work-related dimensions. Instead, where trained and non-trained users varied at all in their work habits and in their attitudes toward micros and training, the variation seemed more related to their desire for training, rather than to the training itself. The authors discuss the findings from this study and propose future research in the area of corporate-provided microcomputer training.
An architecture for distributed knowledge based-systems
Authors: Carlson David A. , Ram Sudha
Published: October 2004

Many management information systems have requirements that are inherently distributed, both logically and physically, however, no adequate architectures exist which allow multiple knowledge bases and databases to be shared and integrated. An architecture for Distributed Knowledge-Based Systems (DKBS) is presented which satisfies these requirements. A Distributed Knowledge Base Management System (DKBMS) is described which manages the meta-knowledge necessary to coordinate multiple local Knowledge-Based Systems (KBSs). We propose an object-oriented design for implementing the DKBMS structure and the communication protocol which connects the DKBMS with each of the KBSs. An application is described where the DKBS architecture might assist managers to integrate several KBSs which represent parts of a strategic plan.
Intensity of end user computing
Authors: Ein-Dor Phillip , Segev Eli
Published: October 2004

Much has been written in recent years on end user computing, based on assumptions concerning the motivations and attributes of end users. Most of this research has been descriptive in nature with little theoretical basis. The empirical study described in this paper was intended to assess factors affecting the intensity of participation in end user computing, while at the same time grounding the research on a firm theoretical base.Theory suggested three major groups of variables affecting intensity of participation in end user computing - organizational factors, top management leadership, and individual factors. Examination of survey data indicated that organizational and top management factors played no part in determining the intensity of EUC while there is a strong relationship between individual factors and intensity of EUC. The individual factors found relevant were reasons for using EUC, use made of the outputs, rank in the organization, years of experience with computers, and the type of hardware used.
Knowledge-based systems for idea processing
Authors: Young Lawrence F.
Published: October 2004

Knowledge-based systems methods have been seen as means of enhancing the nature of support provided by Decision Support Systems. This paper examines how they can be similarly used to provide user guidance and to represent forms of knowledge that are relevant to the newer type of qualitative support systems called Idea Processing. Basic concepts of Idea Processing and Knowledge-based systems are summarized. The paper identifies several modes of knowledge representation appropriate for particular functions of Idea Processing.
A methodology for the design of reuse engineered Ada components
Authors: Latour Larry
Published: October 2004

Reuse Engineering is the discipline of designing and implementing
generic architectures
. We combine the recently proposed 3Cs model of reusable software components with the notions of
separation of concerns
and
genericity
to suggest a methodology for the support of reuse engineering. In doing so we present examples to illustrate the development process.
A strategy for synchronising simplex message streams
Authors: McCaig J. M.
Published: October 2004

In information networks which, for example, employ satellites or LANs with broadcast or multi-cast capability, data flow is often simplex. Various quality of service improvements are possible by using redundant network capacity, which is intended for "fail-over", to carry duplicate message streams instead. This paper examines a strategy for synchronising message streams delivered via diverse but unreliable routes, and illustrates it with a Pascal procedure called Y.
Semantic file systems
Authors: Gifford David K. , Jouvelot Pierre , Sheldon Mark A. , O'Toole James W.
Published: October 2004

A
semantic file system
is an information storage system that provides flexible associative access to the system's contents by automatically extracting attributes from files with file type specific
transducers
. Associative access is provided by a conservative extension to existing tree-structured file system protocols, and by protocols that are designed specifically for content based access. Compatiblity with existing file system protocols is provided by introducing the concept of a
virtual directory
. Virtual directory names are interpreted as queries, and thus provide flexible associative access to files and directories in a manner compatible with existing software. Rapid attribute-based access to file system contents is implemented by automatic extraction and indexing of key properties of file system objects. The automatic indexing of files and directories is called "semantic" because user programmable transducers use information about the semantics of updated file system objects to extract the properties for indexing. Experimental results from a semantic file system implementation support the thesis that semantic file systems present a more effective storage abstraction than do traditional tree structured file systems for information sharing and command level programming.
Designing file systems for digital video and audio
Authors: Rangan P. Venkat , Vin Harrick M.
Published: October 2004

We address the unique requirements of a multimedia file system such as continuous storage and retrieval of media, maintenance of synchronization between multiple media streams, and efficient manipulation of huge media objects. We present a model that relates disk and device characteristics to the recording rate, and derive storage
granularity
and
scattering
parameters that guarantee continuous access. In order for the file system to support multiple concurrent requests, we develop
admission control algorithms
for determining whether a new request can be accepted without violating the realtime constraints of any of the requests.We define a
strand
as an immutable sequence of continuously recorded media samples, and then present a
multimedia rope
abstraction which is a collection of individual media strands tied together by synchronization information. We devise operations for efficient manipulation of multi-stranded ropes, and develop an algorithm for maintaining the scattering parameter during editing so as to guarantee continuous playback of edited ropes.We have implemented a prototype multimedia file system, which serves as a testbed for experimenting with policies and algorithms for multimedia storage. We present our initial experiences with using the file system.
Scheduler activations
Authors: Anderson Thomas E. , Bershad Brian N. , Lazowska Edward D. , Levy Henry M.
Published: October 2004

Threads
are the vehicle for concurrency in many approaches to parallel programming. Threads separate the notion of a sequential execution stream from the other aspects of traditional UNIX-like processes, such as address spaces and I/O descriptors. The objective of this separation is to make the expression and control of parallelism sufficiently cheap that the programmer or compiler can exploit even fine-grained parallelism with acceptable overhead.Threads can be supported either by the operating system kernel or by user-level library code in the application address space, but neither approach has been fully satisfactory. This paper addresses this dilemma. First, we argue that the performance of kernel threads is
inherently
worse than that of user-level threads, rather than this being an artifact of existing implementations; we thus argue that managing parallelism at the user level is essential to high-performance parallel computing. Next, we argue that the lack of system integration exhibited by user-level threads is a consequence of the lack of kernel support for user-level threads provided by contemporary multiprocessor operating systems; we thus argue that kernel threads or processes, as currently conceived, are the
wrong abstraction
on which to support user-level management of parallelism. Finally, we describe the design, implementation, and performance of a new kernel interface and user-level thread package that together provide the same functionality as kernel threads without compromising the performance and flexibility advantages of user-level management of parallelism.
Using continuations to implement thread management and communication in operating systems
Authors: Draves Richard P. , Bershad Brian N. , Rashid Richard F. , Dean Randall W.
Published: October 2004

We have improved the performance of the Mach 3.0 operating system by redesigning its internal thread and interprocess communication facilities to use
continuations
as the basis for control transfer. Compared to previous versions of Mach 3.0, our new system consumes 85% less space per thread. Cross-address space remote procedure calls execute 14% faster. Exception handling runs over 60% faster.In addition to improving system performance, we have used continuations to generalize many control transfer optimizations that are common to operating systems, and have recast those optimizations in terms of a single implementation methodology. This paper describes our experiences with using continuations in the Mach operating system.
The robustness of NUMA memory management
Authors: LaRowe Richard P. , Ellis Carla Schlatter , Kaplan Laurence S.
Published: October 2004

The study of operating systems level memory management policies for nonuniform memory access time (NUMA) shared memory multiprocessors is an area of active research. Previous results have suggested that the best policy choice often depends on the application under consideration, while others have reported that the best policy depends on the particular architecture. Since both observations have merit, we explore the concept of policy tuning on an application/architecture basis.We introduce a highly tunable dynamic page placement policy for NUMA multiprocessors, and address issues related to the tuning of that policy to different architectures and applications. Experimental data acquired from our DUnX operating system running on two different NUMA multiprocessors are used to evaluate the usefulness, importance, and ease of policy tuning.Our results indicate that while varying some of the parameters can have dramatic effects on performance, it is easy to select a set of default parameter settings that result in good performance for each of our test applications on both architectures. This apparent robustness of our parameterized policy raises the possibility of machine-independent memory management for NUMA-class machines.
Automatic reconfiguration in Autonet
Authors: Rodeheffer Thomas L. , Schroeder Michael D.
Published: October 2004

Autonet is a switch-based local area network using 100 Mbit/s full-duplex point-to-point links. Crossbar switches are interconnected to other switches and to host controllers in an arbitrary pattern. Switch hardware uses the destination address in each packet to determine the proper outgoing link for the next step in the path from source to destination. Autonet automatically recalculates these forwarding paths in response to failures and additions of network components. This automatic reconfiguration allows the network to continue normal operation without need of human intervention. Reconfiguration occurs quickly enough that higher-level protocols are not disrupted. This paper describes the fault monitoring and topology acquisition mechanisms that are central to automatic reconfiguration in Autonet.