bluuebunny/crossref_metadata_2025 huggingface dataset:
On approximation in the humanities
Authors: Ross Donald , Bratley Paul
Published: January 2007

We argue briefly that studies in the humanities can suffer as much from too great a concern for rigor as from too little. This leads us to propose a research methodology more tolerant of error and approximation than those which are usually taught at the moment.
Can function word distribution indicate authorship?
Authors: Wyatt James L.
Published: January 2007

The writer's interest in the answer to the question contained in the title of this paper stems from his discovery of seemingly startling aberrations in word frequency distributions in the Celestina, an anonymous work of Spanish literature which conceivably could be the product of one, two, or three authors. This work appeared in 1499 with sixteen parts. An edition in 1501 also appeared with sixteen parts but contained a letter "to a friend" stating that the first part was written by one unnamed person and that the succeeding fifteen parts were written by the author of the letter, identified acrostically as Fernando de Rojas in some verses forming a part of the letter. An edition in 1502 contained five additional parts inserted between the fourteenth and fifteenth original parts, and the original fourteenth part was considerably amplified. There has been much discussion and debate, but the consensus today is that there was a single author of the work.
Statistical techniques for free-text processing
Authors: Morris John M.
Published: January 2007

Over the past eight years we have developed statistical methods for characterizing, classifying, and retrieving brief natural-language messages. Our goal was to provide a tool for people who had to deal with enormous numbers of heterogeneous documents, using ill-defined criteria of relevance and interest. Initially, we worked with a large, general-purpose system, the On-Line Pattern Analysis and Recogition System (OLPARS). More recently, we have developed a system called Message Extraction Through Estimation of Relevance (METER). Our present aim is the construction of a Testbed system for further studies and the development of more complex systems.
A computer-generated phrase index from document titles
Authors: Nunnery Nancy
Published: January 2007

A computer program was written in SPITBOL to generate a printed phrase index from document titles. The documents to be indexed were theses and dissertations, which tend to have informative and specific titles. It was hoped that a phrase index would be more useful than either a KWOK or KWIK index, since the former sacrifices precision for recall, while the latter is unnecessarily cumbersome.
Software testing and certification
Authors: Keirstead Ralph E. , Parker Donn B.
Published: January 2007

Society needs a continous flow of upgradding products and services which are responsive to needs, are reliable, cost-effective and safe. When this does not occur, excessive regulation and resulting stifled technology and production results. Excesses in both directions have occurred in other fields such as medicine, the automobile industry, petro-chemicals, motion pictures, building construction and pharmaceuticals. Disasters based on poor design and implementation in information processing have occurred in ballot-counting systems, law enforcement systems, billing systems, credit systems and dating services. Business has been undersold and oversold and sometimes reached the brink of ruin in its increasing reliance on computer systems. The only answer is a balanced degree of self-regulation. Such self-regulation for software systems is presented here.
On comparing apples and oranges, or, my machine is better than your machine
Authors: Kernighan B. W. , Plauger P. J. , Plauger D. J.
Published: January 2007

In a recent comparison test, six computer manufacturers were asked to code a particular program loop to run as quickly as possible on their machine. Presumably conclusions about the merits of the machines were to be drawn from the resulting code.We have reduced the number of Instructions for the loop by an average of one instruction per machine, a 15% decrease. It appears that conclusions might more appropriately be drawn about manufacturers' software.
Review of "Statistical Computer Performance Evaluation by Walter Frieberger"; Academic Press (1972).
Authors: Denning Peter J.
Published: January 2007

This book is the proceedings of a conference held at Brown University on November 22-23, 1971. The editors state that only papers dealing with real data in a reasonably sophisticated manner were accepted for the conference. Papers dealing simply with the collection of data, or with queueing-theoretic models, were excluded. The papers are grouped into seven sections corresponding to the seven sessions at the conference; at the end of each section is a brief statement by the one or two discussants of that session's papers.
On cost of static linking and loading of subprograms
Authors: Beck Norman , Ashby Gordon
Published: January 2007

The purpose of this paper is to report some data concerning cost in CPU processing due to loading programs. The data was collected on a PDP-10, using modifications made by the linking loader to the prologue generated for FORTRAN complied programs, by the addition of one UUO (a programmed operation similar to an SVC on IBM 360/370), and several cells in the monitor used as counters. The data covers the number of programs loaded and the CPU ms expended loading them. This data is broken down between programs that were loaded and never entered and programs loaded and eventually executed. It is further classified according to periods of heavy use for program development and periods of heavy production use.
A note on high resolution timing
Authors: Wortman David B.
Published: January 2007

The ability to accurately time the execution of sequences of machine instructions is an important tool in the tuning and evaluation of computer hardware and software. The complexity of modern hardware and software systems often makes accurate timing information difficult to obtain [1]. This note describes an experimental comparison of timing information provided by a large multiprogramming operating system (OS/360 MVT) with timing information derived directly from a high resolution hardware clock. The hardware clock was found to be a superior source of timing information.
A technique for comparative analysis of Kiviat graphs
Authors: Merrill H. E. Barry
Published: January 2007

The article in September, 1973 Performance Evaluation Review demonstrated again the utility of the Kiviat Graph as a visual display of system profiles. A simple extension of the concept of the Kiviat Graph permits a realistic (though not necessarily linear) comparison of two Kiviat graphs.
A comparison of software and hardware monitors
Authors: Peterson Thomas G.
Published: January 2007

Tests were performed to compare the accuracy of two computer system monitors. Specifically, results from a hardware monitor were compared with results from a software monitor. Some of the subreports produced by the software monitor were quite accurate; other subreports were not quite so accurate, but they were consistent from run to run. In view of these test results, it appears that the software monitor can be used to measure the effects of changes made in a system tuning project.
Benchmarked comparison of terminal support systems for IBM 360 computers
Authors: Syms Gordon H.
Published: January 2007

A set of terminal scripts and benchmarks were derived for comparing the performance of time sharing and batch computer operating systems. Some of the problems encountered in designing valid benchmarks for comparing computer operating systems under both terminal and batch loads are discussed.The results of comparing TSS/360, CP/67 and MTS time sharing systems for the IBM 360/67 over a wide range of load conditions are presented. The results of comparing TSS, MTS and OS/MVT under batch loads are also presented. The tests were conducted with Simplex and Dual processor configurations with 256K bytes to 768K bytes of main memory.The conclusions were quite surprizing in that CP/67 running on a minimal system performed competitively with TSS/360 on a much larger dual processor system. With equal configurations CP/67 out performed TSS/360 by a wide margin. Furthermore, MTS providing both batch and terminal support produced performance that was 5 percent to 25 percent better than the split configuration with CP/67 providing the terminal support and OS/MVT providing the batch processing support.Serious performance degradation of the time sharing computer systems from overloading was experienced and a simple solution is suggested to prevent such degradation. The degradation was so severe as to render the performance less than that of a sequential job processor system.
A note on Syms' benchmarked comparison
Authors: Lujanac Paul L.
Published: January 2007

If the load factor is expressed linearly as a fraction of the capacity of a terminal-oriented system, we assume that response times increase more or less exponentially with an increase in load factor. Syms' load factor is nonlinear, and, in fact, was designed to "make the terminal response times approximately a linear function of the load factors."
Further comments on comparative evaluation of Kiviat graphs
Authors: Merrill H. W. Barry
Published: January 2007

Mike Morris has presented an excellent discussion in these pages (1) of the use of Kiviat Graphs for Computer Performance Evaluation, referencing another fine article (2) which proposed a technique for analytic comparisons (rankings) of these Graphs. Morris also proposes that these techniques may be very useful in describing system performance, and suggests a different method for calculation of "Figures of Merit" of Kiviat Graphs.
Managing computer performance with control limits
Authors: Bell Thomas E.
Published: January 2007

Dr. Bell received his doctorate in Operations Management from the University of California at Los Angeles in 1968. He immediately joined the Rand Corporation as a Member of the Technical Staff in its Computer Science Department and undertook research in the simulation and perfomance improvement of computing systems. During this research he participated in the definition of the Extendable Computer System Simulator, the development of a methodology for computer performance improvement, and analysis of large, multi-machine computer installations. He also analyzed requirements for future command-and-control systems and for logistic systems, in order to determine required system functions and hardware size. He left Rand in early 1974 to join the Software Research and Technology Staff of TRW Systems Group where he is currently developing improved techniques to specify the requirements of computer software systems.
Costoptimal reliability of data processing systems
Authors: Terplan Kornel
Published: January 2007

With the advent of third generation computing systems, the increase in complexity and power has reached a degree which exceeds the human ability to understand, to analyze, to predict, and to optimize system performance and reliability. The only method that can help is measurement. In defining measurement purposes, one has to define which measurable quantities in the system are significant and which may be ignored. But, at the present time, we do not know in general what is relevant in the measurements. For the sake of clarity, it is useful to define several levels of measurement- organizational level- computer center level- computing system level- job level- computer subsystem level.
Usage statistics for MTS
Authors: Landwehr Carl E.
Published: January 2007

The following report is presented in response to Professor Browne's request for case studies of performance measurement projects; this study takes a macroscopic view of a large-scale time sharing and batch processing installation.
Issues in computer performance evaluation
Authors: Boehm B. W. , Bell T. E.
Published: January 2007

This paper summarizes the results of an ACM/NBS Workshop on Computer Performance Evaluation. Computer Performance Evaluation (CPE) was selected as the subject of an ACM/NBS Workshop because of the significant leverage CPE activities can have on computer usage. This paper describes a number of conclusions abstracted from the discussions as well as presenting recommendations formally adopted by the participants. While several of these conclusions indicate that improvements are needed in performance analysis tools, another suggests that improved application of CPE could be achieved by better documentation of analysis approaches. More integration of data collection and modeling are considered necessary for the performance analysis field to develop its full potential. Participants noted that the common emphasis on data collection or modeling, to the exclusion of considering objectives, often seriously degrades the value of performance analyses; the only savings that really count from a performance analysis are the ones that appear on the bottom line of the balance sheet.
Benchmark construction
Authors: Barber Eric Ole , Asphjell Arne , Dispen Arve
Published: January 2007

A partially automated method of generating benchmarks for comparison of EXEC 8 with other systems has been developed as one step in preparation for choosing a new computer at the University of Trondheim.
Shape in ranking Kiviat graphs
Authors: Calcagni John M.
Published: January 2007

The purpose of this paper is to address the topic of ranking or comparing Kiviat Graphs. Several articles have appeared on the subject. For background information the reader is directed to the original article by Philip Kiviat and Kenneth Kolence (1) and to the articles on ranking by Barry Merrill (2, 4) and Michael Morris (3). The main emphasis here will be on showing how automatic inclusion of axis-value normalizations and hence of pattern normalization can be achieved. It is hoped that this will be one way of making the ranking of Kiviat Graphs more meaningful and hence more useful. Pattern recognition is, after all, one of the main reasons for using the Kiviat Graph technique.
Iconic representation of the human face with computer graphics
Authors: Eisenfeld J. , Barker David R. , Mishelvich David J.
Published: January 2007

There are many applications for the iconic representation of the human face. The program dicussed here was designed to describe the face by means of measurements made on a skeletal radiograph and, in particular, could be used to indicate changes resulting from oral surgery (2). The computer generated faces are drawn using a program modified by the authors which was produced and kindly given to us by Mr Robert Jacob and Dr William H Huggins of the Johns Hopkins University. Their program was based on that developed by Dr Herman Chernoff (1) of Stanford University. The program was originally designed for the presentation of multivariate statistical data and was modified by Jacob and Huggins for use in iconic communication. As are sult of our modifications, the mouth, nose, and facial outline are presented more realistically, the data input is interactive and quicker, especially when only a few input variables are more directly related to facial components to facilitate accuracy in drawing.
Defining a computer resource unit
Authors: Luderer Gottfried W. R.
Published: January 2007

A method for the construction of a resource component charging formula for computer service in a multiprogramming system is defined. Charges are proportional to relative resource costs, to fractional resource use with regard to total expected resource usage, and the intent is to recover cost without profit or loss. Further, a method is presented that simplifies the treatment of overhead or unallocatable resource costs. An aggregate "Computer Resource Unit" is defined, which attempts to characterize workload in a system-invariant way. Experiences with this concept and its limitations are discussed. Recommendations for those planning to introduce a similar concept are given.
Proposal for instruction time objectives
Authors: Roehr K. , Niebel K.
Published: January 2007

The designer of an instruction processing unit is generally faced with the problem to implement a machine able to execute a given instruction set within given timing and cost constraints. A very common method to state instruction timing constraints is by means of an average instruction time
Simulation of the load of an interactive system
Authors: Brandwajn A.
Published: January 2007

We describe a simulator of interactive users designed for the resource sharing system ESOPE. We stress the guide-lines of the design as well as the problems of interface with the operating system, of measurements, and of perturbations caused by the simulator in the statistics gathered.We show two examples of an application of the simulator to the design of a resource-sharing system, viz., to an anlysis of load regulation policies, and to an evaluation of the improvement in system performance one may expect from implementing shared translators.Finally, we use the load simulator to validate a mathematical model. The latter is developped by step-wise refinement, using measured values of model parameters, till a good agreement between the performance indices computed from our model and those measured in a real system under simulated load, is obtained. It is observed that, for most of the performance measures considered, a simple model matches fairly well the "real world".
Quantile estimation in regenerative simulation
Authors: Coppens G. W. J. , van Dongen M. P. F. M. , Kleijnen J. P. C.
Published: January 2007

We model key-punching in a computer center as a queunig simulation with 2 servers (typists) and 3 priority classes (small, medium, large jobs). The 90% quantile of queuing time is estimated for different borderlines between the 3 job classes. Confidence intervals for the quantiles are based on the regenerative properties of the simulation, as derived by Iglehart (1974). They utilize the asymptotic normality of the estimated quantile, and a rather complicated expression for its variance. Numerical results are given for the quantiles (and averages) of the queuing times in each job class, for several borderlines between the 3 job classes. The effects of simulation runlength on the confidence intervals were also examined. The effects of varying job-class borderlines were tentatively modeled by a regression model.
How fast is "real-time"?
Authors: Estell Robert G.
Published: January 2007

A single bench mark test was compiled and run on the AN/UYK-7 computer, and on a number of commercial computers, in order to measure the relative thrupt of the UYK-7, which is the Navy's large scale real-time computer. The results indicate the speeds and accuracies of each host; however, general conclusions can be drawn only with some risk.
A simple model for cost considerations in a batch multiprocessor environment
Authors: Mills Philip M.
Published: January 2007

This paper describes a simple model which provides a procedure for estimating the effect of additional hardware on run time. The additional hardware may be additional processors, more powerful processors, an increase in memory size or additional memory modules. Run time is related to cost effectiveness. A measure of memory interference in the form of effective processing power is determined for multiprocessors and used in the formulation of run time. The overall procedure allows the user to compare different multiprocessor hardware configurations on a cost effective basis.
An interactive benchmark for a multi-user minicomputer system
Authors: Buchanan Irene , Duce David A
Published: January 2007

The work that forms the basis for this paper was undertaken as part of an exercise to purchase two multi-user minicomputer systems to be developed as interactive facilities for grant holders supported by the Engineering Board of the United Kingdom Science Research Council.
Tuning
Authors: Buzen J. P.
Published: January 2007

Tuning is basically a two stage process: the first stage consists of detecting performance problems within a system, and the second stage consists of changing the system to correct these problems. Measurement tools such as hardware monitors, software monitors and accounting packages are typically used in the first stage, and tools such as optimizers, simulators and balancers are sometimes used in the second stage.
Some fundamentals of price theory for computer services
Authors: Cotton Ira W.
Published: January 2007

Classical microeconomics focuses on the behavior of producers and consumers in a market setting. The behavior of producers is examined in terms of production functions (the relationship of factor inputs to product outputs) and positioning relative to the market. Of particular concern is the effect of firm size and organization on the production functions for its various products. There is a continuing change in the scale of production, differentiation of products, and integration of supply in the search for the most profitable overall strategy.
Considerations in pricing distributed computing
Authors: Kimbleton Stephen R.
Published: January 2007

A technical need for computer system pricing policies was manifest with the introduction of multiprogrammed computing equipment. However, organizational considerations related to the realities of computing in a single site environment effectively precluded allocation of significant time or effort to this subject.
User experience
Authors: Gutsche Richard H.
Published: January 2007

Security Pacific is the tenth largest bank in the United States, operating 500 banking locations in the State of California. Our Electronic Data Processing Department serves the entire system from its Glendale Operations Center and a satellite center in Hayward. The Hayward location serves as an input/output center for our Northern California banking offices. Data Transmission provides for centralization of all accounting functions.
Functional distribution of the workload of a linked computer system and its simulation
Authors: Lazos Constantine
Published: January 2007

Consideration is given to a possible functional distribution of the workload over two linked computers with separate channel access to a large disc store, into the resource utilisation of the linked system achieved by simulation using a modified and re-entrant single processor simulator. Results suggest that the proposed distribution realises a high utilisation.
Pricing D.P. products
Authors: Scott Shirley E.
Published: January 2007

Periodically, vending Data Processing organizations are faced with the task of establishing service rates for a resources provided to Customers. Sigmetrics' Technical Meeting on Pricing Computer Services (November, 1975) is a good indicator of the amount and variety of interest the topic generates. The proceedings from that meeting were a key source of reference for the formulation and implementation of a pricing strategy and automated model in one of Xerox's timesharing data centers.
Simultaneous resource possession in queueing models of computers
Authors: Sauer C. H. , MacNair E. A.
Published: January 2007

Neglect of simultaneous resource possession is a significant problem with queueing network models of computers. This is illustrated by examples of memory contention and channel contention with position sensing I/O devices. A class of extended queueing networks is defined to allow representation of simulataneous resource possession. Extended queueing network models of memory contention and channel contention are given. Solution techniques and numerical results for these models are discussed.
Solving parametric linear systems
Authors: Ballarin Clemens , Kauers Manuel
Published: January 2007

Algorithms in computer algebra are usually designed for a fixed set of domains. For example, algorithms over the domain of polynomials are not applicable to parameters because the inherent assumption that the indeterminate
X
bears no algebraic relation to other objects is violated.We propose to use a technique from model theory known as
constraint programming
to gain more flexibility, and we show how it can be applied to the Gaussian algorithm to be used for parametric systems. Our experiments suggest that in practice this leads to results comparable to the algorithm for parametric linear systems by Sit [9] --- at least if the parameters are sparse.
Review of "Computational Commutative Algebra I by Martin Kreuzer and Lorenzo Robbiano", Springer Verlag, 2000, ISBN 3-540-67733-X.
Authors: González-Vega Laureano , Recio Tomás
Published: January 2007

Authors, we can assume, start writing a book with
pleasure
. As their project progresses, their basic mood might turn to
hope
(of soon getting to the end of an overwhelming project). Conversely, readers, we assume, to start browsing a book with hope (of learning something interesting) but only in some special cases do they continue reading it with
pleasure
.
Getting the most out of a small computer
Authors: Janusz Edward R.
Published: January 2007

When a lengthy procurement results in a computer too small for the growing needs of the organization, a restrictive set of controls is necessary to "stretch" the available resource until a new procurement cycle can remedy the shortfall. This article discusses the development of such controls, their effect on computer usage and their positive as well as negative impact on the organization.
Structural validation in queueing network models of computer systems
Authors: Muramatsu Hiroshi , Date Masahiro , Maki Takanori
Published: January 2007

Queueing network models have established their role in performance evaluation of computer systems [1]. These models have a sound theoretical background, and require less computational effort than other techniques. And they have proved to be practical in many case studies. Evaluation using simple models is powerful, especially in predicting system behaviour, and makes the internal structure of computer systems more understandable than evaluation using benchmarks. However, the modeling approach forces us to validate the model. Queueing network models are no exception to this point.
An approach to interactive performance analysis in a busy production system (NOS/BE)
Authors: Nemeth Thomas A
Published: January 2007

Many different ideas have been promulgated on performance evaluation by software and hardware monitoring or modelling, but most of these have associated implementation problems in practice. By adopting a slightly different approach, (using an approximation to "service wait time"), an analysis of response is possible in a production system, with negligible overhead. This analysis allows the actual areas of contention to be identified, and some rather unexpected results emerge, with a direct application to scheduling policy. The work was done using the NOS/BE operating system on a CDC Cyber 173 at the University of adelaide.
The power of the read track and the need for a write track command for disk back-up and restore utilities
Authors: Marrevee J.
Published: January 2007

In the mid-seventies, together with the introduction of the IBM storage control unit 3830-II, a new disk command came available that gives the user the possibility to read an unknown amount of user data of a complete disk track by using only 1 channel command.
A model for predicting the response time of an on-line system for electronic fund transfer
Authors: Perros H. G.
Published: January 2007

An on-line system used by a large bank for electronic transfer of funds was modelled with a view to predicting its mean response time. A simple regression model of the mean response time of the supporting disk I/O configuration was first developed. This was then incorporated into a higher-level global analytic model of the on-line system. The analytic model was based on simple results from queueing theory. In particular, the underlying model was a open queue network with no restrictions imposed on the number of customers permitted at any node. The accuracy of the model was demonstrated by comparing it against actual data. The model is of wide applicability though it was originally developed for a particular system.
PROFGEN
Authors: Fishwick Paul A. , Feyock Stefan
Published: January 2007

Many of the tools used in software metrics for evaluating the execution characteristics of a program are predicated on specific counting rules for operators and operands [1, 2]. The analyst may use these counting techniques to determine such program attributes as estimation of object code size prior to actual compilation and the relative efficiencies of various language compilers. Operator/operand measures provide useful results for certain analyses, but a deficiency exists in that the data derived from this technique does not directly reflect the program structure afforded by a high-level language such as FORTRAN, Pascal, or Ada. There are many instances where it is desirable to measure the program at the source level where the execution data may be directly associated with specific high level program units such as source statements and blocks.
Performance evaluation of a job scheduler
Authors: Jones Greg A.
Published: January 2007

International Business Machines' (IBM) Job Entry Subsystem 3 (JES 3) is the integral part of the MVS operating system that is responsible for controlling all jobs from their entry into the system until their exit out of the system. JES 3 maintains total awareness of each job while it is in the system and services the jobs upon request. These services include: prearing the job for execution, selecting the job for execution, and the processing of SYSIN/SYSOUT data. This paper reports the findings of the performance evaluation study of JES 3 through the use of a General Purpose Simulation System (GPSS) model of JES 3 and exhibits the benefits of using simulation models to study complex sytems such as JES 3. Once the model was developed, it was used to evaluate the effects of varying the job scheduler parameters of JES 3 in the batch job environment. The input workload and service times for the model were derived from System Management Facilities (SMF) and Resource Management Facilities (RMF) data from the modeled system.
Instruction entropy, a possible measure of program/architecture compatibility
Authors: Gaffney John E.
Published: January 2007

Several metrics related to the distribution of use of instructions in a program have been developed. They appear to have potential for assessing the degree to which a program "matches" the architecture of the host computer. Also, they may serve as the basis for bridging the gap between the software science metrics of Halstead and others that focus on the static qualities of the programming process and the resulting software product and dynamic measures such as MIPS often used for comparison of system performance.
A performance measurement and system evaluation project plan proposal
Authors: Knudson Michael E.
Published: January 2007

This document is an outline for a performance measurement and evaluation effort. Performance measurements consist of producing data showing frequency and execution times for components of computer systems. Components implies:1)hardware2)ucode3)macrocode4)applications software5)systems (e.g., utilities in an operating-system environment)Evaluation can be broken down into several areas. Principle areas of interest are comparative performance evaluation and an analysis of a system's structure/behavior. Comparative evaluation consists of: relative performance measurements of different machines; a summary of collected data; and an analysis of a system's structure, including the production of data describing the interrelationship of system components. This data may be narrative, but the preferred technique is a graphical presentation showing component relationships.
Review of "OS-1100 performance algorithms: a guide to the resource allocation algorithms of OS-1100 by John C. Kelly".
Authors: Ryu In Kyung
Published: January 2007

The book describes the algorithms which were used by OS-1100 to manage the resources of Sperry 1100 computer systems, and lists the parameters that may affect the performance of OS-1100. However, the book fails in providing the reader how the algorithms and the parameters affect the performance of OS-1100. It is not clear to the reader why the algorithm in OS-1100 was selected and how to tune the parameters.
Building IMS synthetic workloads
Authors: Domanski Bernard
Published: January 2007

Historically, workload characterization, and cluster analysis in particular, has been a proven technique when applied to performance evaluation / capacity planning studies. Given the problem of constructing a synthetic workload that represents a production workload, our goal is to use this technique to identify a
concise
, yet accurate set of work units that will compose the workload. For IMS, these work units are transactions. Yet the selection of transactions must be done with care; for an additional goal must be to identify a
concise
, yet accurate set of databases that are required by the transactions. This paper will review clustering techniques, and apply them to drive the transaction selection process. An algorithm is also presented that identifies the technique behind database selection. A case study follows that illustrates the implementation of the methodology.
End to end delays in a catenet environment
Authors: Körner Ulf , Fdida Serge , Perros Harry , Shapiro Gerald
Published: January 2007

This paper presents a hierarchical model for a catenet environment. The model consists of three levels of models, and it reflects the end to end delay between two host computers each connected to a different LAN. The two LANs are connected via gateways by a WAN. The model incorporates a basic flow control mechanism, standardized local area network behaviour, as well as gateway functions in terms of packet fragmentation and reassembly. The model can be used to obtain performance measures such as the mean end to end delay and the system's throughput as a function of parameters such as arrival rate of packets, maximum window size, and traffic mix.
Computer system modelling and simulation
Authors: Kreutzer Wolfgang
Published: January 2007

To evaluate the suitability and limitations of software for computer systems modelling, a basic comprehension of the structure of such tools must be provided. A brief discussion of conceptual requirements for the description of discrete models, and computer system models in particular, is followed by a survey of commercially available computer simulation packages. Special and general purpose discrete event simulation and general purpose programming languages are also analysed for their suitability for this class of applications. The survey closes with some recommendations and guidelines for selection and application of computer system simulation tools.To aid the analyst contemplating a computer system modelling project, a brief list of relevant addresses and annotated references is also included.
Computer performance evaluation
Authors: Clark Jon D. , Reynolds Thomas J. , Intille Michael J.
Published: January 2007

Computer performance evaluation can be delineated into the areas of selection, projection and monitoring. The tuning of existing systems for efficient performance may be viewed as a special case of the projection activity involving modeling, statistics collection and analysis. Mosts tools available today are expensive to use and overly complicated. This paper presents the comparison of two, relatively simple and cost-effective, statistical techniques for performance evaluation: regression and canonical analysis. In addition, the results of the suggested and implemented computer configuration modification is reported.
Techniques in simulation which enhance software reliability
Authors: Willis Ron
Published: January 2007

A simplified simulation study of an actual software development effort is presented. A model is developed and exercised through various stages of modifications to an originally unreliable soft ware design until viable software design results. Techniques in model development, simulation, analysis, and language capability which lead to enhanced software reliability are discussed. Uniquenesses in the approach presented are contrasted to simulation methods which lack this capability.
Capacity planning for MVS computer systems
Authors: Artis H. Pat
Published: January 2007

The current status of an implementation of a methodology relating load, capacity and service for IBM MVS computer systems is presented. This methodology encompasses systems whose workloads include batch, time sharing and transaction processing. The implementation includes workload classification, mix representation and analysis, automatic benchmarking, and exhaust point forecasting.
What's a working set?
Authors: Denning Peter J.
Published: January 2007

I am writing about the paper by A. Petrella and H. Farrey, of IBM, SIMULATING WORKING SETS UNDER MVS, reprinted in the SIGMETRICS Newsletter, Issue (8, 4), winter 1979-80. The paper is an amalgam of very good modeling work and misinformation about the working set concept. I will summarize the important contributions and give a short essay about working sets.
Simulating working sets under MVS
Authors: Petrella Arthur , Farrey Harold
Published: January 2007

The concept of a "working-set" of a program running in a virtual memory environment is now so familiar that many of us fail to realize just how little we really know about what it is, what it means, and what can be done to make such knowledge actually useful. This follows, perhaps, from the abstract and apparently intangible facade that tends to obscure the meaning of working set. What we cannot measure of ten ranks high in curiosity value, but ranks low in pragmatic utility. Where we have measures, as in the page-seconds of SMF/MVS, the situation becomes even more curious: here a single number purports to tell us something about the working set of a program, and maybe something about the working sets of other concurrent programs, but not very much about either.This paper describes a case in which the concept of the elusive working set has been encountered in practice, has been intensively analyzed, and finally, has been confronted in its own realm. It has been trapped, wrapped, and, at last, forced to reveal it self for what it really is. It is not a number! Yet it can be measured. And what it is, together with its measures, turns out to be something not only high in curiosity value, but also something very useful as a means to predict the page faulting behavior of a program running in a relatively complex multiprogrmmed environment.The information presented here relates to experience gained during the conversion of a discrete event simulation model to a hybrid model which employs analytical techniques to forecast the duration of "steady-state" intervals between mix-change events in the simulation of a network-scheduled job stream processing on a 370/168-3AP under MVS. The specific "encounter" with the concept of working sets came about when an analytical treatment of program paging was incorporated into the model. As a result of considerable luck, ingenuity, and brute-force empiricism, the model won.Several examples of empirically derived characteristic working set functions, together with typical model results, are supported with a discussion of relevant modeling techniques and areas of application.
Capacity planning
Authors: Moran Thomas S.
Published: January 2007

Some comments on past, present, and future measures of volume as it affects planning for computer systems.
Breaking the language barrier
Authors: DeMarco Tom
Published: January 2007

The systems analyst and the user are not independent entities; each depends on the other. When communication problems get in their way, however, the relationship can turn adversary.The real problem in most system or program development efforts may be that English, left to itself, is too subtle, too open to personal interpretation, to be appropriate in the structured world of DP.Tom DeMarco shows how to impose limits on our native language so analysts, designers, programmers and users can safely use it to define what they are trying to develop. This week he starts by giving some hints on that most basic of DP jobs, setting up the system.
System evaluation methodologies
Authors: Erlandson Robert F.
Published: January 2007

It is a difficult task to evaluate existing large-scale systems; it is even more difficult to evaluate alternative designs for future systems. Yet, such decisions are necessary because of the long development and implementation times involved. Decisions must be made today about future systems for telecommunications, power, health-care delivery, trasportation, etc. These systems change slowly because additions or modifications are costly and must mesh with the existing elements, hence, great care must be given to the establishment of long-term goals and the evaluation of alternative future system designs.
Empirical investigation of the effectiveness of several computer performance evaluation tools
Authors: Clark Jon D. , Golladay Robert M.
Published: January 2007

A number of tools exist for computer selection evaluation. The operational cost of applying these vary considerably as does the precision of the performance prediction. This paper compares the precision of several commonly used methods in a single test case, namely cycle time, instruction mix analysis and benchmarking.
A tale of two islands
Authors: Denning Peter J.
Published: January 2007

Once upon a time there were two islands. One was called Stochasia. Its citizens were well cultured and they had achieved high development in a system of mathematics for random processes. The other island was called Operatia. Its citizens were well cultured and they had achieved high development in a system for experimentation with nondeterminate phenomena. Both civilizations were closed societies. Neither knew of the other's existence, and it had been so since the beginning of time. Neither would ever have known, had it not been for the events I will describe shortly.
ADP capacity planning
Authors: Yader Mark J.
Published: January 2007

A case study of short-range ADP capacity planning is presented and related to the process of long-range planning. Short-range capacity planning is concerned with identification of computer and communication resources which will reach saturation levels in the near future. The initial step in the short-range planning process is to evaluate the performance of the user's current system configuration and one or more configuration enhancements with respect to their effectiveness in supporting a projected workload. Central to long-range planning is the evaluation of a broader range of architectural alternatives, including various distributed processing design. In both short range and long range planning, system modeling is a basic tool for evaluating alternatives. An analytic network of queues model has been developed to reflect both centralized and hierarchically distributed network architectures. The application of the tool as part of the short-range case study is described.
How friendly and fast is FAST DUMP RESTORE
Authors: Marrevée J.
Published: January 2007

FAST DUMP RESTORE, shortly named FDR, is a very well known software package, delivered by the software house Innovation Data Processing, and in some countries of Europe commercially supported by Westinghouse. This package is used in many computer centres using one of IBM's big operating systems e.g. MVT or MVS. According to Innovation's own remarks it became one of the most succesful software products in the world with about 3000 users, and since 1974 it is every year on the DATAPRO HONOR ROLL. It should, among others, provide superior performance on creation of dumps or restores of disk packs.
Design algorithms for asynchronous operations in cache memory
Authors: Hać Anna
Published: January 2007

The algorithms used to operate on disk buffer cache memory have significant impact on operating system performance. The buffer cache size, the size of the file being written, the disk access time, and the algorithms used to append updated blocks from the buffer cache to the disk queue determine performance of operations in disk cache memory. The determination of these algorithms is particularly important since they are implemented in the system kernel and cannot be changed by the user or system administrator.This paper introduces new algorithms for asynchronous operations in disk buffer cache memory. These algorithms allow for writing the files into the buffer cache by the processes. The number of active processes in the system and the length of the queue to the disk buffer cache are considered in the algorithm design. This information is obtained dynamically during the execution of the algorithms. The performance of the operations on the buffer cache is improved by using the algorithms, which allow for writing the contents of the buffer cache to the disk depending on the system load and the write activity. The elapsed time of writing a file into the buffer cache is calculated. The waiting time to start writing a file is also considered. It is shown that the elapsed time of writing a file decreases by using the algorithms, which write the blocks to the disk depending on the rate of write operations and the number of active processes in the system. The time for a block to become available for update in the buffer cache is given. The number of blocks available for update in the buffer cache is derived. The performance of the algorithms is compared. It is shown that the proposed algorithms allow for better performance than an algorithm that does not use the information about the system load.
Approximations for the halstead software science software error rate and project effort estimators
Authors: Schneider Victor
Published: January 2007

Experimental estimators are presented relating the expected number of software errors (B) in a software development project to* the overal1 reported months of programmer effort for the project (E)* the number of subprograms (n)* the count of thousands of coded source statements (s)These estimators are [EQUATION]These estimators are shown to be consistent with data obtained from, the air force Rome air developement center, the naval research laboratory, and Fujitsu corporation. It is suggested here that more data is needed to refine these estimators further.
A queueing model for local area network bridges
Authors: Irvin David R.
Published: January 2007

The buffer needed to match the transmission speeds of two different local area networks interconnected by a MAC-layer bridge is modeled as a G/M/1 queue. To account for the problems caused by the arrivals of traffic bursts from the higher-speed network, traffic interarrival times are assumed to follow a hyperexponential probabilty density function. Selecting parameters for the hyperexponential distribution to model realistic traffic conditions is examined. A hypothetical bridge is discussed as an example. Queue length for the G/M/1 system with hyperexponential interarrivals is shown to depend primarily on the persistence of bursts on the higher-speed network.
Human factors in computer systems
Authors: Hansen W. J.
Published: January 2007

Evaluating Text Editors (Session 3B), chaired by Henry Ledgard, Human Factors Limited, and John Whitside, Digital Equipment Corporation. Text editing is probably the one activity that users spend the most time performing, so it is appropriate to devote considerable attention to improving its human factors. This session covered several techniques for evaluation of text editors.