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Showing papers on "Systems architecture published in 1983"


Journal ArticleDOI
10 Oct 1983
TL;DR: The complete system architecture is outlined in this paper, and that experience in its use has been summarized.
Abstract: LOCUS is a distributed operating system which supports transparent access to data through a network wide filesystem, permits automatic replication of storage, supports transparent distributed process execution, supplies a number of high reliability functions such as nested transactions, and is upward compatible with Unix. Partitioned operation of subnet's and their dynamic merge is also supported.The system has been operational for about two years at UCLA and extensive experience in its use has been obtained. The complete system architecture is outlined in this paper, and that experience is summarized.

473 citations


Proceedings Article
22 Aug 1983
TL;DR: The architecture is a declarative control language that allows one to write partial specifications of program behavior that facilitates incremental system development and the integration of disparate architectures like demons, object-oriented programming, and controlled deduction.
Abstract: One of the biggest problems in AT programming is the difficulty of specifying control. Meta-level architecture is a knowledge engineering approach to coping with this difficulty. The key feature of the architecture is a declarative control language that allows one to write partial specifications of program behavior. This flexibility facilitates incremental system development and the integration of disparate architectures like demons, object-oriented programming, and controlled deduction. This paper presents the language, describes an appropriate, and discusses the issues of compiling. It illustrates the architecture with a variety of examples and reports some experience in using the architecture in building expert systems.

101 citations


Proceedings Article
01 Jan 1983
TL;DR: In this article, the authors discuss human factors and system architecture and offer best-guess guidelines for what a system should be like and how it should be developed, and suggest ways in which advances in research and education could result in systems with better human factors.
Abstract: While it is becoming increasingly obvious that the fundamental architecture of a system has a profound Influence on the quality of its human factors, the vast majority of human factors studies concern the surface of hardware (keyboards, screens) or the very surface of the software (command names, menu formats). In this paper, we discuss human factors and system architecture. We offer best-guess guidelines for what a system should be like and how it should be developed. In addition, we suggest ways in which advances in research and education could result in systems with better human factors. This paper is based on an address by L. M. Branscomb and a publication by the authors in the Proceedings of the IFIP 9th World Computer Congress, Paris, France, September 19-23, 1983.

90 citations


Journal ArticleDOI
TL;DR: This paper outlines the principles on which the U.S. Department of Defense packet internet architecture is based and characterizes some of the protocols which implement the architecture.

68 citations


Journal ArticleDOI
TL;DR: Research in the modeling of organizations, constraint- based job-shop scheduling, organization simulation, user interfaces, and system architecture is described, and examples of working systems are provided.

53 citations


Patent
04 May 1983
TL;DR: In this article, a distributed computer system is described in which each computing element includes a hardware message filter which provides content tag recognition and selection, and the overall system architecture allows software modularity and both hardware and software extensibility.
Abstract: An apparatus and method of intercomputer communications based on message broadcast with receiver selection is taught. A distributed computer system is described in which each computing element includes a hardware message filter which provides content tag recognition and selection. The overall system architecture allows software modularity and both hardware and software extensibility. The message filter can be preset or dynamically programmed, and can be operated in conjunction with a serial or parallel broadcast bus.

53 citations


Journal ArticleDOI
TL;DR: Architectural issues faced in the design and implementation of Bridge Communications' gateway products are explored to illustrate a few types of gateway services and their specific architectural requirements.
Abstract: Local area network technology is rapidly evolving to fill the need for shared, distributed resources and data. The use of LANs in factory automation, office automation, and distributed data processing systems reflects the variety of approaches in use today. This real need for different technologies to solve different applications, together with the competitive nature of the systems business, is making the need to communicate among different types of LANs increasingly clear. In addition, local network systems require access to remote resources and information. The solution to the interconnection of different types of local networks, and the connection of local networks to long-haul networks, is the use of high-performance internetworking gateways and bridges. Internetworking enables the development of hybrid networks and offers the best of all technologies. Only with these hybrid network systems can we achieve a truly integrated, multivendor network system. LANs have been developed to solve the problems of interconnecting different types of equipment. LAN technology has been driven by the sometimes conflicting requirements of interfacing to an installed equipment base with many price/performance levels and multiple interface standards. As multiple types of networks have evolved to solve diverse networking problems, so have multiple types of internetworking gateways evolved to solve different internetworking problems. In this article, we will explore architectural issues faced in the design and implementation of Bridge Communications' gateway products. Several examples of internetworking applications are presented to illustrate a few types of gateway services and their specific architectural requirements.

28 citations


Journal ArticleDOI
W. E. Kluge1
TL;DR: This paper presents a concept and a system architecture for the concurrent execution of program expressions of a concrete reduction language based on λ-expressions.
Abstract: This paper presents a concept and a system architecture for the concurrent execution of program expressions of a concrete reduction language based on ?-expressions.

28 citations


Journal ArticleDOI
Meyer-Ebrecht1, Wendler
TL;DR: A thorough architectural approach is urgently required to decorrelate user requirements from technical and manufacturing boundary conditions and produce generic concepts for system modules and procedures down to the bottom system level.
Abstract: Digital archiving of diagnostic images has been in demand for many years-particularly since optical mass storage technology increased the chances of its realization. Technically, the digital picture archive was regarded as a giant data store with film input and hardcopy or soft-copy output-a simple and straightforward concept. Then, as more and more digital imaging machines were implemented in hospitals, mass storage media for archiving the digital pictures were looked upon as peripheral devices to the picture-generating machines. Meanwhile, it was becoming obvious that digital picture archives would be far more than isolated devices or extensions to existing isolated devices. Instead, they would become the kernel of networks that would connect a variety of imaging machines, interact with hospital databases and administration systems, and, last but not least, facilitate communication of pictorial and other information between medical personnel. This perspective added tremendous complexity to the concept. Complexity is mainly a consequence of looking at PACS from the standpoint of the user, the network engineer, the designer of imaging (sub)systems, or the manufacturer of high-technology key components. For instance, the user's demands conflict with the manufac-turer's product strategy. The user needs a system that is highly adaptable in terms of functions and structure to his individual work situation. The manufacturer, however, for the sake of economy, must produce standard products with a fixed catalog of functions. Another complication is that some well-established, basic data processing concepts have to be thrown overboard when innovative technologies, techniques, and methods are employed to process, store, and communicate a large number of high-resolution pictures with sufficient speed. Hasty development with inadequate concepts can result in the proliferation of confusing and redundant systems. A thorough architectural approach is urgently required to decorrelate user requirements from technical and manufacturing boundary conditions and produce generic concepts for system modules and procedures down to the bottom system level. This article presents a general procedure for an adequate architectural approach and describes in detail concepts for solving the basic technical problems. A conceptual process must be top down, but where is the top and where is the bottom? The structure of a process depends on the observer's perspective. A PACS is a typical example of a system with multiple dimensions, including user, network, system management, data processing , and other dimensions. The system architect's primary mission is to define the system's dimensions such that conceptual models from the different perspectives become …

20 citations


Proceedings Article
01 Jan 1983

13 citations


Journal ArticleDOI
TL;DR: A novel system architecture is introduced which allows improved performance at marginal increase in storage cost, thereby allowing overall memory savings for a given performance index when compared with a conventional classifier structure.

Proceedings ArticleDOI
01 Jan 1983
TL;DR: A multi-discipline integrated analysis capability, designed to aid the engineering community in coupling of existing modules and in handling of the associated software and data, which consists of an executive program which manages tasks and data.
Abstract: The paper describes a multi-discipline integrated analysis capability, designed to aid the engineering community in coupling of existing modules and in handling of the associated software and data. This capability consists of an executive program which manages tasks and data, a number of technical modules, graphics and special purpose modules, inter-module data flow interfaces, and associated user documentation. The current implementation provides specific modules and coupled solution paths for the thermal, structures and controls technologies. However, the system has been designed to serve also as a framework into which user groups may incorporate other modules and technologies. Details of the system architecture are discussed, in the context of the major design decisions and the software development and usage experience. The paper provides a brief discussion of some other integrated systems which are available or under development.

Journal ArticleDOI
Webb T. Comfort1
TL;DR: A number of significant new features designed to support fault-tolerant operation are discussed, including a duplex control bus, a computer interconnection system, a technique for remote diagnostics, a single-button maintenance procedure, and special fault-handling software.
Abstract: This paper describes the architecture of a computer system, being designed and built for the U.S. Navy, that is expected to be the standard Navy shipboard computer for the next twenty years or so. It has a requirement for very high system reliability, which is addressed by a multiprocessor system configuration that can recover dynamically from hardware faults and support on-line repair of failed hardware elements. Successfully accomplishing this requires various types of redundant hardware elements and special system architecture features, as well as intelligent fault-recovery software. This also requires that the application programs be designed to participate fully in the recovery and reconfiguration process. This paper presents the overall system architecture and discusses a number of significant new features designed to support fault-tolerant operation, including a duplex control bus, a computer interconnection system, a technique for remote diagnostics, a single-button maintenance procedure, and special fault-handling software.

Journal ArticleDOI
01 Dec 1983
TL;DR: The system architecture, protocol structure, implementation options, and message transfer and interpersonal messaging services are described for a worldwide electronic mail system.
Abstract: Message-Handling Systems provide store-and-forward electronic mail services. In 1984, CCITT will approve a set of Recommendations defining standards to interconnect systems throughout the world. This paper describes international efforts to develop the standards which are necessary for a worldwide electronic mail system. The system architecture, protocol structure, implementation options, and message transfer and interpersonal messaging services are described.

01 Jan 1983
TL;DR: The ELXSI operating system consists of processes which communicate only via messages, and hardware, architecture and software decisions which facilitate and exploit the message approach are described.
Abstract: The ELXSI operating system consists of processes which communicate only via messages. Hardware, architecture and software decisions which facilitate and exploit the message approach are described. Multiprocessing, caching and I/O architecture aspects of the minicomputer system are given particular attention. 3 references.


Journal ArticleDOI
TL;DR: This paper is both an introduction to the EAS-E software architecture and an example of the usefulness of the entity-attribute-set view.
Abstract: EAS-E is an application development system based on an entity-attribute-set view of system description. It consists of a procedural language for manipulating data base and main storage entities, and direct (nonprocedural) facilities for interrogating and updating data base entities. The EAS-E software itself was implemented with the entity-attribute-set view. This paper reviews some of the EAS-E features and considers some of its implementation details. This paper is both an introduction to the EAS-E software architecture and an example of the usefulness of the entity-attribute-set view.

Proceedings ArticleDOI
13 Jun 1983
TL;DR: The paper outlines the principles for the concurrent evaluation of applicative programs based on Berklings reduction language, which lends itself to a recursive partitioning scheme which can elegantly be mapped onto a system of cooperating reduction machines featuring a stack architecture.
Abstract: The paper outlines the principles for the concurrent evaluation of applicative programs based on Berklings reduction language. The recursive style of program design supported by this language lends itself to a recursive partitioning scheme which, for suitable program expressions, generates dynamically a hierarchy of processes for the concurrent evaluation of subexpressions. This hierarchy can elegantly be mapped onto a system of cooperating reduction machines featuring a stack architecture. A special ticket mechanism enforces an upper limit on the number of processes that, at any time, may exist within the system, which does not significantly exceed the number of the available machines.

Journal ArticleDOI
TL;DR: The 3B20D diagnostics provide a high degree of modularity and portability using an operating-system-based structure, and is used in a wide range of development, production, and maintenance activities throughout the project life cycle.
Abstract: Comprehensive diagnostic tests and multifeatured control software designed for execution on several host processors help craft to quickly isolate faulty hardware anywhere in the 3B20D Processor. Besides meeting the requirements for Bell System switching systems, the 3B20D diagnostics provide a high degree of modularity and portability using an operating-system-based structure. The diagnostics are used in a wide range of development, production, and maintenance activities throughout the project life cycle. Many features of the system architecture and hardware are provided to allow thorough diagnosis in a time-shared noninterfering manner. Additional features are provided in the diagnostic control structure to extend the DMERT diagnostic capabilities to application systems based on the 3B20D Processor.

Proceedings ArticleDOI
27 Jun 1983
TL;DR: A general-purpose, interactive simulation facility for modeling computational systems is described, especially suited for evaluating the performance of parallel computational structures on workloads exhibiting arbitrary degrees of parallelism.
Abstract: A general-purpose, interactive simulation facility for modeling computational systems is described. The simulation facility is especially suited for evaluating the performance of parallel computational structures on workloads exhibiting arbitrary degrees of parallelism. Two different simulators are provided, one that operates at the processor level only, ignoring explicit system connectivity; and one that allows a detailed specification of system architecture and connectivity. Supplementing the simulators are: (a) a workload generator for synthesizing workloads exhibiting any desired degree of parallelism, and (b) a resource specification system that allows easy description of the capabilities and parameters of various resources in a system. Several graphical utility programs are provided to aid in interpretation of simulation results. The system has been implemented in the programming language 'C' on a Data General MV/8000 computer operating under the Data General Advanced Operating System; the system should port easily to other virtual architecture machines with a 'C' compiler.

Proceedings ArticleDOI
16 May 1983
TL;DR: This paper reviews one project, the Intelligent Peripheral Interface (IPI), in particular, and references the application area of the Small Computer Systems Interface (SCSI).
Abstract: The American National Standards Institute (ANSI) work committees on computer interfaces are actively developing proposed standards that will affect almost all vendors of computers and peripherals. This paper reviews one project, the Intelligent Peripheral Interface (IPI), in particular, and references the application area of the Small Computer Systems Interface (SCSI).The architecture of future computer systems is going to depend in large part on the types of interfaces used, because of the ever-increasing role that peripherals play in systems performance, cost, availability, and reliability. The capability of peripherals dictates system performance---more than the central processor does, in most configurations. The cost of peripherals represents more than half of what the user pays for a system.The interface chosen to interconnect peripherals has a major influence on the cost and performance tradeoffs that a vendor can make. This paper addresses these issues with regard to the ANSI efforts on intelligent interfaces.

01 Jan 1983
TL;DR: Primary issues addressed include parallel algorithm design; operating system structure; user interaction; task execution environment; task management, scheduling, and preloading; memory management for the control units; and system performance.
Abstract: The design of PASMOS, a distributed operating system for the PASM parallel processing system is considered. PASM is a partitionable SIMD/MIMD multimicrocomputer system. PASMOS has a hierarchical structure and is distributed throughout the hardware components of PASM. The architecture of the PASM system is overviewed and existing multiprocessor operating systems are surveyed. Parallel algorithms which compose a scenario for image contour extraction are developed. The scenario is used to demonstrate the operating system facilities required to support SIMD/MIMD task execution. The distributed software components of PASMOS and the facilities which these components provide to enable the system to create virtual SIMD/MIMD machines are described. The PASM command language, which allows users to interact with the PASM system, is presented. When the maximum task execution time is known a priori, task scheduling for a partitionable parallel processing system, such as PASM, is a two-dimensional bin packing problem. By applying a power of two constraint (given by the system architecture) on the number of processors which can compose a virtual machine, a new worst case bound is derived for Baker and Schwarz's first-fit shelf algorithm. Requiring the user to specify the maximum allowable execution time of a task before the task can be scheduled is a major limitation. A class of multiple-queue task scheduling algorithms which do not have this limitation is developed and applied to the PASM system. To improve processor utilization, it is desirable to overlap the operation of the secondary storage with computations being performed by the processors. Due to the dynamically reconfigurable architecture of PASM, a task must be preloaded prior to the schedulers final selection of processors. Two schemes which allow the system to preload input data and programs into the primary memories for upcoming tasks are presented and compared. The multiple control units in PASM share a common secondary storage for programs. The optimal service rate for the common secondary storage is determined. In summary, primary issues addressed include parallel algorithm design; operating system structure; user interaction; task execution environment; task management, scheduling, and preloading; memory management for the control units; and system performance.

01 Apr 1983
TL;DR: In this paper, the approach, study results, and recommendations for defining and selecting space station architectural options are described and evaluated based on the degree of mission capture versus cost and required funding rate, where mission capture refers to the number of missions accommodated by the particular architecture.
Abstract: The approach, study results, and recommendations for defining and selecting space station architectural options are described. Space station system architecture is defined as the arrangement of elements (manned and unmanned on-orbit facilities, shuttle vehicles, orbital transfer vehicles, etc.), the number of these elements, their location (orbital inclination and altitude, and their functional performance capability, power, volume, crew, etc.). Architectural options are evaluated based on the degree of mission capture versus cost and required funding rate. Mission capture refers to the number of missions accommodated by the particular architecture.

Dissertation
01 Jan 1983
TL;DR: Traditional, self-evolving methods and principles of building production are looked upon as constituting systems, which are not designed by anybody and serve the needs of both production and use, but substantially differ from the designed building systems.
Abstract: This work is an inquiry into the interventions of the systems design in the whole building process. At the beginning, three approaches which represent different points of view of interventions in production and use are exposed and compared to each other, and one of them serves as the theoretical background of this thesis. It is accepted that interventions in both production and use aspects of the whole building process might be capable of producing valuable solutions, as this notion is determined in the first chapter. Interventions in the production aspect are looked upon as influencing the relations among physical elements and as depending on the process of production which is followed. Here the interest (i.e., producer, designer, client or user), which determines the process of building production, is of importance. The process of production certainly affects the performance of the building product after the building is occupied, and all factors influencing the building performance constitute the use aspect of the whole building process. Changes in the building process produce changes in the use aspect. Systems, which change the building process according to the needs of both the production and use, are considered as intervening in both the production and the use aspect of the whole building process. Finally, traditional, self-evolving methods and principles of building production are looked upon as constituting systems, which are not designed by anybody and serve the needs of both production and use, but substantially differ from the designed building systems. Such differences will be exposed in the last part of my thesis. Thesis Supervisor: Dr. Eric Dluhosch Associate Professor of Building Technology Title:

Proceedings ArticleDOI
17 Mar 1983
TL;DR: In this paper, a high speed, automated video inspection system has been developed for the inspection of graphite structures in aircraft, including detection of flaws in graphite material as it is dispensed, ply identification, and verification of position and orientation on a robot transfer head.
Abstract: The extensive use of graphite structures in aircraft has created a need for new manufacturing and quality assurance techniques. As a part of the Integrated Flexible Automation Center development program, a high speed, automated video inspection system has been developed. This system presently interfaces with four video cameras and a solid state linear array camera. The inspection tasks for this application include detection of flaws in graphite material as it is dispensed, ply identification, and verification of position and orientation on a robot transfer head. Inspection problems and system architecture are described in this paper.

Journal ArticleDOI
TL;DR: The digital speech interpolation (DSI) module is the most complex unit in a TDMA traffic terminal and the one which presents the most options to the equipment designer, and requires a judicious selection of technologies.
Abstract: The digital speech interpolation (DSI) module is the most complex unit in a TDMA traffic terminal and the one which presents the most options to the equipment designer. The merits of various design approaches are contrasted and compared. The options arise in the choice of architectures and technologies for the realization of the module. There are several aspects to architectural choice in the unit design involving the amount of storage and nature of storage in the unit, the nature and type of the high speed interface, the nature of echo protection features, FEC encoding, and the degree and nature of the human interface for test and maintenance. In terms of storage, because the interpolation process takes time, the unit is by necessity memory-oriented and efficient choice of memory architecture is important. The two principal design choices here may be called "order and storage" and "storage and order." Store-and-order implies storage of data on all received channels (whether they are to be processed or not) followed by data routing for selected channels. Order-and-store implies immediate selection of that traffic to be processed. The architecture is also influenced by the choice of interface between the DSI and the "satellite" side equipment. The principal choice lies between word- and bit-oriented data transmission, but there are tradeoffs involving handshaking for control signals as well. The INTELSAT specifications governing DSI module performance give designers of specific equipment wide latitude in the human interface for testing and maintenance features and for the extent to which the unit will support the accumulation of traffic data statistics. The implications to system architecture of these choices are dealt with. Whatever the architecture may be, DSI module design requires a judicious selection of technologies. Among the questions are: memory technologies, allocation of functions among hardware and software, contending computer technologies for software implementation, and buffer design. The choices in software versus hardware implementations revolves around the various satellite channel to international channel mappings the unit must perform, and around the overload channel processing. Single card and single chip computers are shown to be useful tools in the design. Because of the interpolated nature of DSI operation, the design of a DSI unit is in a sense incomplete without an accompanying traffic simulator to verify performance. This unit performs the task of providing tests signals which contend for channels on a statistical basis.

Journal ArticleDOI
TL;DR: In this paper, the authors have discussed two critical problems which are appearing during a design procedure of an Integrated Microprocessor-based Control and Protection System to be applied in H.V.

Proceedings ArticleDOI
01 Jan 1983
TL;DR: The papear extends previous work to show that through the combined use of time referencing and stable flight algorithms, individual microprocessors can be configured to autonomously tolerate intermittent faults.
Abstract: The paper discusses the implementation of fault tolerant digital flight control and navigation systems for rotorcraft application It is shown that in implementing fault tolerance at the systems level using advanced LSI/VLSI technology, aircraft physical layout and flight systems requirements tend to define a system architecture of distributed, asynchronous microprocessors in which fault tolerance can be achieved locally through hardware redundancy and/or globally through application of analytical redundancy The effects of asynchronism on the execution of dynamic flight software is discussed It is shown that if the asynchronous microprocessors have knowledge of time, these errors can be significantly reduced through appropiate modifications of the flight software Finally, the papear extends previous work to show that through the combined use of time referencing and stable flight algorithms, individual microprocessors can be configured to autonomously tolerate intermittent faults


Journal ArticleDOI
TL;DR: The general purpose of the Message system is described and the functions of the Name Server and the Message Server, an end-to-end Message protocol, are briefly described.