bluuebunny/crossref_metadata_2025_split huggingface dataset:
Near-complete decomposability of queueing networks with clusters of strongly interacting servers
Authors: Vantilborgh Hendrik T. , Garner Richard L. , Lazowska Edward D. 
Published: January 2007

The near-complete decomposability of queueing network models of computer systems is generally supported by very large differences in the service rates of the servers. In this paper we show how such models may still be nearly completely decomposable if on the one hand these large differences can no longer be realistically assumed (as is the case, for example, in computer networks) but if on the other hand clusters of strongly interacting servers exist.
Our results may be viewed as a bridge between the approaches to the approximate analysis of queueing networks advanced by Courtois and by Chandy, Herzog and Woo, since we show circumstances under which the former approach leads to exactly the same method of analysis as the latter. In contrast to the Chandy, Herzog and Woo theorem, however, the theory of near-complete decomposability does not rely on the beneficent properties of queueing networks exhibiting product form solutions. Thus our results may point the way towards the theoretically sound application of simple and intuitively appealing approximate analysis techniques to non - product form networks.
On the existence of composite flow equivalent markovian servers
Authors: Stewart William J. , Zeiszler Gerald A. 
Published: January 2007

Queueing networks have been used to model a large variety of complex systems. However, once a realistic model has been constructed it has generally been necessary to distort and modify it so that an analytic solution could be obtained. Unfortunately, the analytic solution often has little relation to the original queueing system and consequently often produces solutions with poor accuracy.
We begin with a brief introduction to the concepts of decomposition and aggregation. Application of these and other approximate methods to the analysis of computer systems are discussed by Chandy and Sauer [CHAN78].
Questions for Local Area Network panelists
Authors: Spiegel Mitchell G. 
Published: January 2007

Much has been written and spoken about the capabilities of emerging designs for Local Area Networks (LAN's). The objective for this panel session was to gather together companies and agencies that have brought LAN's into operation. Questions about the performance of LANs have piqued the curiosity of the computer/communications community.
Each member of the panel briefly described his or her LAN installation and workload as a means of introduction to the audience. Questions about performance were arranged into a sequence by performance attributes. Those attributes thought to be of greatest important were discussed first. Discussion on the remainder of the attributes continued as time and audience interaction permitted.
Toward a parametric approach for modeling local area network performance
Authors: Mager Peter S. 
Published: January 2007

The task of modeling the performance of a single computer (host) with associated peripheral devices is now well understood [Computer 80]. In fact, highly usable tools based on analytical modeling techniques are commercially available and in widespread use throughout the industry. [Buzen 78] [Buzen 81] [Won 81] These tools provide a mechanism for describing computerized environments and the workloads to be placed on them in a highly parameterized manner. This is important because it allows users to describe their computer environments in a structured way that avoids unnecessary complexity. It also is helpful in facilitating intuitive interpretations of modeling results and applying them to capacity planning decisions.
A first step toward building a modeling tool and associated network specification language that allows straightforward, inexpensive, and interpretable modeling of multi-computer network performance is to identify the set of characteristics (parameters) that most heavily influence that performance. The result of such a study for the communication aspects of local area networks is the subject of this paper.
Criteria for computer performance analysis
Authors: Dujomović Jozo J. 
Published: January 2007

Computer evaluation, comparison, and selection is essentially a decision process. The decision making is based on a number of worth indicators, including various computer performance indicators. The performance indicators are obtained through the computer performance measurement procedure. Consequently, this procedure should be completely conditioned by the decision process.
This paper investigates various aspects of computer performance measurement and evaluation procedure within the context of computer evaluation, comparison and selection process based on the Logic Scoring of Preference method. The set of elementary criteria for performance evaluation is proposed and the corresponding set of performance indicators is defined. The necessary performance measurements are based on the standardized set of synthetic benchmark programs and include three separate measurements: monoprogramming performance measurement, multiprogramming performance measurement, and multiprogramming efficiency measurement. Using the proposed elementary criteria, the measured performance indicators can be transformed into elementary preferences and aggregated with other non-performance elementary preferences obtained through the evaluation process. The applicability of presented elementary criteria is illustrated by numerical examples.
An introduction to the simulation of a multiple CPU military communications system
Authors: Sprung James G. , Beatty Paul T. , Camery John W. , Norrell John C. 
Published: January 2007

All telecommunication systems design, development and support for the Headquarters, Department of the Army, is provided by the Automation Support Detachment. The current operational telecommunication system provides the Army with a full range of communication functions, i.e., receipt, transmission, message validation and online CRT operations, on a dedicated IBM System/360 (Model 50) processor. The system is designed to handle 1500 messages per hour with an average message size of 2000 characters operating on a round-the-clock basis.
Design efforts are currently underway to extend the capabilities of the present system and to provide similar operational services to all communication centers within the Pentagon. The proposed system will include a mixture of minicomputers and an IBM System/360 (Model 65) and will support a workload of 6000 messages per hour. The design effort involves computer simulation of the proposed system.
This paper describes the development of a comprehensive “system” of three models which represent the Front End Control, Message Processing, and Staff Service Center Subsystems. These models are written in ECSS II and are linked by special message generation modules. The special processing requirements as well as the multiple CPU configuration present some unique modeling situations.
The form the model has taken is predicated to a large extent, on the available data. Extensive use is made of hardware and software monitoring of the IBM System/360 (Model 50) and the analysis of message traffic statistics. The modeling of the traffic statistics. The modeling of the input processing is statistically related to the output processing The processing is functionally divided into stages to provide a high level of generality for the models and add uniformity throughout the models. Various simulation statistics are gathered for each stage besides the usual ECSS II generated statistics.
Model validation techniques and future uses of the model are described. A discussion of specific simulation techniques and outputs is beyond the scope of this overview document and, therefore, is deferred to future papers.
A Diagnostic Emulator for HEAO software development
Authors: Beer Peter H. , Hupf Kenneth J. 
Published: January 2007

Diagnostic Emulation is the application of microprogramming to the emulation of an operational computer to support software development and verification for that computer. A conventional technique, Interpretive Computer Simulation (ICS), has been used for many years in support of such software development and verification efforts. The ICS method is becoming less cost effective. For the development of attitude control software for NASA's High Energy Astronomical Observatory (HEAO) diagnostic emulation was considered as an alternative.
This paper describes the motivation for using an ICS or diagnostic emulator to validate command and control software, the potential advantages of microprogramming, and the analysis which led to the development of the HEAO Diagnostic Emulator rather than the use of conventional techniques. Also discussed are the emulator implementation tradeoff analysis, the resulting program design, and the interface between the microprogram and the assembly language modules. The results to date are described, including the capability, speed, and reliability of the program and initial user response.
What if mass storage were free?
Authors: Copeland George 
Published: January 2007

This paper investigates how database systems would be designed and used under the limiting-case assumption that mass storage is free. It is argued that free mass storage would free database systems from the limitations and problems caused by conventional deletion techniques. A non-deletion strategy would significantly simplify database systems and their operation, as well as increase their functionality and availability. Consideration of this limiting case helps shed light on a more realistic argument: if the cost of mass storage were low enough, then deletion would become undesirable.
It is also argued that the often labor-intensive costs and time delays involved in archival and retrieval of older data can be minimized if a single technology were available with low-cost on-line storage and a low-cost archival media with long shelf life.
Optical discs promise to come one to two orders of magnitude closer to the limiting case of free mass storage than ever before. Other features of optical discs include improved reliability and a single technology for both on-line and archival storage with a long shelf life. Because of these features and because of (not in spite of) their non-deletion limitation, it is argued that optical discs fit the requirements of database systems better than magnetic discs and tapes.
Design and implementation of a flexible and interactive microprogram simulator
Authors: Mezzalama M. , Prinetto P. 
Published: January 2007

In the present paper a microprogrammable architecture oriented simulator is described. This simulator structure may be logically subdivided in four independent blocks: Supervisor, Interface Module, Simulation Monitor, Simulation Routines.
A high degree of flexibility is obtained by means of a highly hierarchical structure of software and an easy-to-modify table-driven system description. Moreover particular care has been devoted to user-simulator communication via an easy-to-use command language. The use of the simulator in the development of a microprogrammable machine (based on Am2900 bit-slice microprocessors) is described.
Recent progress in the performance evaluation of fundamental allocation algorithms
Authors: Coffman E. G. 
Published: January 2007

Our understanding of several allocation algorithms basic to operating systems and to data base systems has improved substantially as a result of a number of research efforts within the past one or two years. The results have stirred considerable excitement in both theorists and practitioners. This is not only because of the inroads made into long-standing problems, but also because of the surprising nature of the results; in particular, we refer to proofs that certain classical algorithms described as approximate are in fact optimal in a strong probabilistic sense.
The work discussed here will be classified according to the application areas, archival and dynamic storage allocation. In both cases we are concerned with the packing problems that arise in making efficient use of storage. Equivalents of the archival problems also have importance in scheduling applications [4]; however, we shall focus exclusively on the storage allocation setting.
Stationary deterministic flows in discrete systems
Authors: Gelenbe Erol 
Published: January 2007

We consider a deterministic system whose state space is the n-dimensional first orthant. It may be considered as a network of (deterministic) queues, a Karp-Miller vector addition system, a Petrinet, a complex computer system, etc. Weak assumptions are then made concerning the asymptotic or limiting behaviour of the instants at which events are observed accross a cut in the system : these instants may be considered as "arrival" or "departure" instants. Thus, like in operational analysis, we deal with deterministic and observable properties and we need no stochastic assumptions or restrictions (such as independence, identical distributions, etc.).
We consider however asymptotic or stationary properties, as in conventional queueing analysis. Under our assumptions a set of standard theorems are proved: concerning arrival and departure instant measures, concerning, "birth and death" type equations, and concerning Little's formula. Our intention is to set the framework for a new approach to performance modelling of computer systems in a context close to that used in actual measurements, but taking into account infinite time behaviour in order to take advantage of the useful mathematical properties of asymptotic results.
Modeling reentrant and nonreentrant software
Authors: Agre Jon R. , Tripathi Satish K. 
Published: January 2007

A description of software module models for computer systems is presented. The software module models are based on a two level description, the software level and the hardware level, of the computer system. In the software module level it is possible to model performance effects of software traits such as reentrant and nonreentrant type software modules. The resulting queueing network models are, in general, not of the product form class and approximation schemes are employed as solution techniques.
An example of a software module model of a hypothetical computer system is presented. The model is solved with a simulation program and three approximation schemes. The approximation results were compared with the simulation results and some schemes are found to produce good estimates of the effects of changing from reentrant to non-reentrant software modules.
Control and pricing in stochastic networks with concurrent resource occupancy
Authors: Li Xuan , Yao David D. 
Published: January 2007

Concurrent resource occupancy pervades most engineering and service systems. For example, a multi-leg plane trip requires seat reservation on several connecting flights; a configure-to-order product demands the simultaneous processing of all its components; a file transfer on the Internet needs band-width on all the links along its route from source to destination. The object of our study is a network with stochastic concurrent occupancy of resources. The network can be physical (e.g., a telecommunication network), or virtual (e.g., the Worldwide Web), or relational (e.g., the bill of materials of a product, representing its configuration of all components); and both the demand/order arrivals and their processing times required of the resources are stochastic. Our goal is to do revenue optimization in the network through two decisions: (a) <i>pricing:</i> to determine the price charged to each job class and its dynamic adjustment over time; and (b) <i>resource control:</i> to regulate the distribution of resources among the job classes, in particular, when to accept/reject a job and from which class.
Below, we highlight a new <i>fixed-point approximation</i> for a network operating under a set of thresholds that control the access of jobs from each class. With this fixed-point approximation, the resource control problem takes the form of setting the optimal thresholds, which can be formulated and solved as a linear program. To determine the optimal prices then amounts to solving another set of optimality equations on top of the linear program. Furthermore, we can show that our approach via solving optimization problems based on the fixed-point approximation is optimal in some asymptotic sense.
Designing optimum CRT text blinking video image presentation
Authors: Kitakaze Seiji , Kasahara Yutaka 
Published: January 2007

A reference scale has been established to assist in the determination of optimum text blinking times for portions of video image texts being presented on CRT display systems. Optimum text blinking time herein is considered to be that time which most effectively catches and holds viewer attention and quickens his understanding of message import. Three experiments involving questions of the psychology of blinking time were conducted. The first experiment examined subjects' preconceived notions of optimum blinking time, i.e. what they imagined, within their own minds, such times would be for specific text portions. The second experiment determined the gap between those preconceived notions and the subjects' changed concepts of optimum blinking times, based on their experience of visual trials. The third experiment applied a scale of blinking times, based on the experience gained in the second experiment, to a new set of subjects in order to further refine our understanding of optimum intervals. For the portions of text used here, optimum blinking times centered about 1.0 second.
Moreover, through an adaptation to the video image presentation system, the effectiveness of the optimum text blinking times and the psychological scale was confirmed.
Story driven animation
Authors: Takashima Yosuke , Shimazu Hideo , Tomono Masahiro 
Published: January 2007

An animation system has been developed which generates animations from stories written in natural language. The system consists of three modules: story understanding module, stage directing module and action generating module.
The story understanding module extracts actions that are not explicitly described in the story and makes a scenario. The stage directing module adapts the scenario by determining the actors' positions on the stage and setting the stage. Actors are defined as 3-Dimensional articulated figures. Each component of an actor has its primitive motion method. To achieve complicated actions, primitive motions are combined. Referring to these complicated actions, the action generating module produces animated sequences from the adapted scenario. These three modules are tightly coupled with their knowledge bases. As an example, the story of the “Hare and Tortoise” from Aesop's Fables, written for elementary schoolchildren is used. This example proves that it is possible to produce computer animation directly from the story written in natural language, now in Japanese.
Teaching APL to beginners
Authors: Peelle Howard A. 
Published: January 2007

Critical issues recurrently confront APL instructors: How soon to introduce vectors and higher rank arrays? Which Index Origin to start with? What terminology to use? Whether to furnish idioms? Insist on comments in defined functions? Avoid loosing algorithms? Use direct definition? Mention atrophying features? Compare APL with other programming languages? Include extended APL?
Such issues will be discussed, and brief recommendations offered.
Using SCCS to manage APL2 development projects
Authors: Mizel John M. 
Published: January 2007

As workstations become more prevalent and networks expand, APL developers will need source control tools when working together on common programming projects. SCCS (Source Code Control System) is a tool found on UNIX systems used in development projects to control changes made to source code and documentation files. Putting a source file under the control of SCCS creates a single file containing the complete source and history of all modifications with comments. There is a set of SCCS commands to access this file for signing out modules for editing, merging in new changes, providing reports, and even recreating any prior version. Though SCCS is typically used for projects being written in languages like C or Fortran, it can be used in the development of APL2 applications.
In trying to use SCCS, there are some problems unique to APL. Specifically, APL's potential to use all 256 ASCII values does cause problems for SCCS. This paper will provide solutions to these problems, and describe how to use SCCS to manage APL2 application development efforts in a networked environment.
MemSpy: analyzing memory system bottlenecks in programs
Authors: Martonosi Margaret , Gupta Anoop , Anderson Thomas 
Published: January 2007

To cope with the increasing difference between processor and main memory speeds, modern computer systems use deep memory hierarchies. In the presence of such hierarchies, the performance attained by an application is largely determined by its memory reference behavior—if most references hit in the cache, the performance is significantly higher than if most references have to go to main memory. Frequently, it is possible for the programmer to restructure the data or code to achieve better memory reference behavior. Unfortunately, most existing performance debugging tools do not assist the programmer in this component of the overall performance tuning task.
This paper describes MemSpy, a prototype tool that helps programmers identify and fix memory bottlenecks in both sequential and parallel programs. A key aspect of MemSpy is that it introduces the notion of data oriented, in addition to code oriented, performance tuning. Thus, for both source level code objects and data objects, MemSpy provides information such as cache miss rates, causes of cache misses, and in multiprocessors, information on cache invalidations and local versus remote memory misses. MemSpy also introduces a concise matrix presentation to allow programmers to view both code and data oriented statistics at the same time. This paper presents design and implementation issues for MemSpy, and gives a detailed case study using MemSpy to tune a parallel sparse matrix application. It shows how MemSpy helps pinpoint memory system bottlenecks, such as poor spatial locality and interference among data structures, and suggests paths for improvement.