Standard Operating System Research Articles

Performance Analysis Of Service Transmission In The Atm Environment Using A Distributed Simulator

AbstractThis paper presents a distributed simulator for performance analysis of various applications in the asynchronous transfer mode (ATM) environment. The simulator is used to determine how the quality of a service, either synchronous or asynchronous, is affected when it is transmitted through an ATM network under various traffic conditions. The simulator has been implemented in a distributed Unix environment using network and operating system functions and simulates the three lower layers of B-ISDN. It has been based on the time-driven approach, and is modular and expandable because it uses standard operating system calls for adapting new applications and services to the simulator environment. The paper presents performance analysis results of constant and variable bit rate services, as well as experimental results on compressed and uncompressed image transmissions.

An adjustable user interface providing transparent access to application programs for the physically disabled

User interfaces of application programs are usually not designed for the physically disabled [VAN93]. Here we introduce a program for Apple Macintosh computers and PCs using MS-Windows that do assist handicapped users in their interaction with standard application programs. The basic principle is to interact with an interface agent and not with the target application itself, in particular text is entered to the application program via the interface that uses standard operating system mechanisms like the Inter Application Communication (IAC) in the case of the Macintosh. Hence a disabled user may access many different application programs using the same interface. An important feature is the integration of a text prediction component based on the context-sensitive algorithm used in the Reactive Keyboard due to John Darragh and Ian Witten [DWJ90, DAW92]. Currently stable protoype versions for Macintosh and MS-Windows are available.

Mission critical operating systems

Part 1 Operating system design concept: the StarLite operating system choices for mission critical computing operating system correctness is a mission critical requirement the ISIS distributed programming toolkit and the meta distributed operating system - a brief overview the structure of the clouds distributed operating system operating system constructs for managing real-time software complexity. Part 2 Real-time operating system: V - a foundation for mission critical distributed systems MARUTI - an environment for hard real-time applications the spring kernel the ARTS kernel - toward predicatable distributed real-time systems DRAGON SLAYER/MELODY - a highly adaptive distributed operating system for mission critical computing a real-time operating system for HARTS imprecise computations SDEX/44 and 43RSS - navy standard operating systems the kernel computational model of the alpha real-time distributed OS the distributed iRMX operating system - a real-time distributed operating system. Part 3 ADA-based real-time systems: understanding ada runtime environments real-time scheduling theory and ada an overview of DARK.

The use of personal computers in nuclear medicine

Consolidating personal computers (PCs) with nuclear medicine technology can create high computational power comparable with that produced by vendor-specific computer equipment, and at more affordable prices. The integration of a standard platform and operating system with a large installed base has enabled our department to maintain itself at the cutting edge of technology with minimal expense. Along with the savings from the purchase of PC software and hardware come the added advantage of rapid training of staff with minimal in-house effort, especially given the vast educational support in the general community. The integration of a standard platform and operating system with a large installed base has provided the nuclear medicine department with computational resources once unheard of because of economies of scale. The acceptance and integration of a pervasive, flexible technology into nuclear medicine have shown that state-of-the-art studies can be performed at low cost.

NALIGE: a user interface management system for the development of natural language interfaces

One of the major problems encountered by the average computer user is the syntactic inflexibility and linguistic opacity of existing operating system command languages. These characteristics, which are manifested in terms of rigid syntactical rules and cryptic/obtuse acronyms, have been shown to result in significant loss of productivity among novice and intermediate users. This paper investigates one approach to addressing this problem, namely the introduction of natural language interfaces placed on top of the standard operating system command language interpreters. Specifically, it presents a user interface management system which accepts a set of well-formed specifications and produces an autonomous natural language interface exhibiting the prescribed linguistic behavior. These specifications describe the linguistic knowledge to be encapsulated in the target interface in terms of the lexical, syntactic, semantic, and pragmatic elements of the application domain. Additionally, this paper discusses a systematic methodology to be used in identifying the linguistic elements of a given application domain. This methodology consists of a set of formal techniques, computational tools, and three knowledge-base specification languages to be employed by the interface designer during all stages of development and subsequent maintenance of a specific natural language interface.

Real-time UNIX: What performance can we expect?

The paper deals with necessary enhancements of traditional UNIX systems in order to meet the requirements for real-time applications and gives an insight on sources of delays caused by the operating system. A survey of the real-time extensions for POSIX, the ISO/IEC standard operating system, is given. Some key parameters and basic concepts for implementing good real-time performance are discussed. Figures for commonly used metrics are provided.

Fault-Tolerant Multiprocessor for Embedded Process Control

Abstract Workby operation of two multiprocessors implements either integer (safe) or persistent (available) process control systems on the same hardware platform. A tight, pair-wise synchronization allows an early failure detection and a fast switch-over, as required by time-critical plants. The fault-tolerant computer uses off-the-shelf hardware with special features. An additional component, the Update and Synchronization Unit, highly supports the workby operation. The extension of a standard operating system hides redundancy from the user as far as possible, thereby easing the transfer of an application from a single system to the fault-tolerant system. A prototype has been built with components developed and used by a major company for protection and substation control systems. This contribution describes the operating principle and the main design decisions.

Real-Time UNIX: What Performance can we Expect?

The paper deals with necessary enhancements of traditional UNIX systems to meet requirements for real-time applications and gives an insight on sources of delays for application processes caused by the operating system. A survey of the real-time extensions for POSDC, the ISO/IEС standard operating system, is given. Some key parameters and basic concepts for implementing good real-time performance are discussed. Figures for commonly used metrics are reported.

RTX: A Real-Time Operating System Environment for CNC Machine Tool Control

A low cost (IBM/PC microcomputer based) computer numerical controller has been developed and successfully adapted for use in a three-axis milling machine application. The heart of this system is a simple, yet powerful real-time multitasking operating system environment (termed RTX) that was developed as a real-time extension to the standard disk operating system (DOS). Basically, RTX acts as an interrupt driven priority based round-robin scheduler running in the background under DOS. The scheduler is extremely efficient since it is not called at a pre-determined frequency but is called upon demand by the hardware timer of the priority level requesting service. Since the processes running on a given priority level can dynamically set the interrupt rate of the hardware timers, the frequency of execution of the scheduler is infinitely variable. The implementation of RTX for the CNC controller uses three priority levels; however the design philosophy is generic and can be extended to accommodate most system requirements.

ITRON-MP: an adaptive real-time kernel specification for shared-memory multiprocessor systems

A real-time kernel specification named ITRON-MP (industrial-oriented TRON for multiprocessor systems), which defines a standard kernel interface adaptable to various shared-memory multiprocessor architectures, is presented. ITRON-MP is an extension of ITRON, which is a specification of real-time kernels for embedded systems. The ITRON-MP specification is an open architecture, in that anyone can freely implement a kernel based on the specification. A universal implementation of ITRON-MP generates an adapted kernel code for each architecture. This approach presents a standard operating system interface for the development of various real-time systems and improves the efficiency of system development. Moreover, because the executed kernel code is tuned to each architecture, the runtime performance is not degraded by the standardization. The design principles and main features of ITRON-MP are described. >

Experience with MINIX in an operating systems lab

Most standard undergraduate operating systems courses teach theory and concepts, without exposing students to the detailed internal operation or source code of an actual operating system. Tanenbaum's MINIX operating system is designed to give students "hands-on" experience with the internals of an operating system in order to illustrate the theory and concepts. This paper describes the use of MINIX in an operating systems laboratory at the University of Vermont.

Kriging: a method of interpolation for geographical information systems

Geographical information systems could be improved by adding procedures for geostatistical spatial analysis to existing facilities. Most traditional methods of interpolation are based on mathematical as distinct from stochastic models of spatial variation. Spatially distributed data behave more like random variables, however, and regionalized variable theory provides a set of stochastic methods for analysing them. Kriging is the method of interpolation deriving from regionalized variable theory. It depends on expressing spatial variation of the property in terms of the variogram, and it minimizes the prediction errors which are themselves estimated. We describe the procedures and the way we link them using standard operating systems. We illustrate them using examples from case studies, one involving the mapping and control of soil salinity in the Jordan Valley of Israel, the other in semi-arid Botswana where the herbaceous cover was estimated and mapped from aerial photographic survey.

Macintosh Potentials

Much of library microcomputing was initially concentrated on one platform: the IBM PC and its compatibles or equivalents elsewhere. The world of DOS, the IBM or Microsoft standard Disk Operating System — the ‘DOS C:>Prompt’—that began to dominate in business environments with the introduction of spreadsheet programs such as Lotus 1–2–3, also became a de facto standard librarian‐user interface to the world of information. Presentations at library microcomputer conferences and published descriptions of applications and procedures featured DOS‐based systems. For example, of the more than 3,000 entries in a comprehensive bibliography on the application of microcomputers to library operations published in 1987, fewer than 100 were identified in the index as being done on products of the Apple Corporation of Cupertino, California.

Performance of REAL/IX TM -fully preemptive real time UNIX

The UNIX® operating system, developed by AT&T Bell Laboratories, has become a standard operating system gaining rapid acceptance because of its superior flexibility, portability, and a number of support tools to increase programmer productivity. However, UNIX was originally designed for multitasking and time-sharing, and therefore conventional UNIX does not have an adequate response time and data throughput needed to support real-time applications.Many attempts have been made to adapt the UNIX kernel to provide a real-time environment. MODCOMP has developed REAL/IX operating system, which is a fully preemptive, low latency UNIX kernel. This paper discusses real-time performance of REAL/IX and compares it to MASSCOMP RTU operating system.

LIBS 100 running under UNIX at Croydon

VINE 66 (July 1987) reported on the decision by CLSI to move away from the proprietary operating and database management systems used in the past to an industry standard operating system (UNIX). At the same time, the use of Sequent parallel processing computers for large library systems was also announced.

FROM ISLANDS OF AUTOMATION TO THE NEW WORLD OF UNIX

CIM (Computer Integrated Manufacturing) is usually viewed as a vast and complex undertaking which only the General Motors of this world can afford. This article puts forward a simple CIM strategy based on a building block approach using UNIX (the industry standard hardware independent computer operating system). This approach ensures companies start with systems they can afford and also manage. Risks are decreased, small companies too can now build their own CIM strategies. UNIX's great strength is portability and flexibility: companies can start with basic MRP systems and build upon those, integrating at will the more specific elements of CIM as they are needed. The suitability of UNIX for this “mix and match” approach is examined. No longer is there any need to be locked in to one hardware or software supplier. Competitive edge too is improved as the manufacturer can respond quickly to the fluctuating nature of the consumer market. As new products are required, new computer control systems can easily be integrated with the core system.

A Composer's Computer Music System: Practical Considerations

Several factors contribute to the emergence of small but powerful computer music workstations, either as single units in a larger network of computers, or as standalone computer music systems. The current state of hardware and software development has reached a level of sophistication that makes it possible to have access to computer power and programs previously only available on larger computers for a fraction of the price. Major sound synthesis software systems have been rewritten in the C programming language, contributing to their portability and extensibility. This affects systems built within the UNIX environment, as well as those built upon other operating systems, since C has become a significant development language across operating system boundaries. Recent developments that allow for the writing and reading of standard operating system soundfiles make the necessity of designing and maintaining separate soundfile management systems virtually obsolete. The implementation of a variety of userinterface styles to computer music applications has made the creation environment much more accessible to musicians as a whole, and to composers in particular. These factors, combined with decreasing prices for powerful microcomputers, larger and faster disk drives, and the availability of high-quality, lower-cost sound conversion systems, point in a new direction: powerful, dedicated machines for individual artists, smaller computer music facilities, and larger systems based on networks of semiindependent computer music workstations. In order to identify the practical considerations pertaining to the implementation of such a system, it is useful to address the issues in the context of an actual computer music studio installation. The system described has been designed and realized, con-

How to control MVS user supervisor calls

Many computing centres install their own extensions to standard operating systems. These extensions, when processed in an authorized status, may seriously endanger system integrity. This paper, based on case studies over the past five years, spells out the risks run by computing centres under MVS installing home-grown user SuperVisor Calls. A set of design requirements is formulated with which these user SVCs must comply if they are to be considered secure. The latest developments in improving the security of some risky operations are also outlined.

TheUNIXSystem: Theory and Practice in the Construction of a Working Sort Routine

Because comparison in the standard UNIX™ operating system sort routine, /bin/sort, is interpretive, it is generally more time-consuming than the standard paradigm of comparing two integers. When a colleague and I modified sort to improve reliability and efficiency, we found that techniques that improved performance for other sorting applications sometimes degraded the performance of sort. Input and output are important when comparisons are simple, but as comparisons become more complex, the number of comparisons quickly dominates the performance of sort.

Management implications of job control language standardisation

The brief history of command language standardisation efforts is reviewed: time and cost savings are detailed as reasons for requiring a standard operating system command and response language (OSCRL). A model of an abstract computing machine environment is introduced as a desirable kind of environment and as a way for management to understand the standardisation process. Management involvement is seen as all important, not only to support standardisation but to guide the increased flexibility which standardisation brings. Finally, it is stressed that technical experts must get involved to ensure a competent and comprehensive result - even though an actual standard may be five or more years distant.