bluuebunny/crossref_metadata_2025 huggingface dataset:
Undrained anisotropy of Hostun RF loose sand: new experimental investigations
Authors: Finge Zeina , Doanh Thiep , Dubujet Phillippe
Published: January 2007

The undrained behaviour of loose and overconsolidated Hostun RF sand in triaxial compression and extension tests is described. The samples are isotropically or anisotropically overconsolidated along several constant effective stress ratio paths with various overconsolidation ratios (OCR), up to 24. To minimize the effect of variation of density on the observed undrained behaviour, all tested samples are required to have a nearly identical void ratio before the final monotonic undrained shearing. Isotropically overconsolidated and normally consolidated samples exhibit the same phenomenon of partial static liquefaction, but anisotropically overconsolidated specimens reveal a completely different undrained behaviour. A common pseudoelastic response is observed for a given overconsolidation history. This response is induced by recent stress history in terms of effective stress paths, independent of the OCR during overconsolidation. The initial gradient of the effective stress paths seems to depend solely on the direction of the previous linear stress path history. This paper offers a comprehensive understanding of the mechanism of the induced anisotropy of loose sand created by simple linear stress paths from three different initial stress states in the classical triaxial plane. The pseudoelastic response can be adequately modelled by a simple hyperelastic component of the elastoplastic framework.Key words: induced anisotropy, overconsolidation, instability, laboratory undrained tests, sand, hyperelasticity.
EVAPORATION OF A FLUID IN CAPILLARY POROUS MEDIA USING A 3D CORRELATED NETWORK MODEL
Authors: MOREIRA JÚLIO CÉSAR C B R , RAJAGOPAL KRISHNASWAMY
Published: January 2007

We present the results from simulation studies of evaporation of a single fluid in a capillary porous medium. Employing a three-dimensional site-bond correlated network model to represent a porous medium, namely Clashac sandstone, we analyze different aspects of the phase distribution by evaporation of a single fluid in the porous medium. As a direct consequence of the porous medium utilized, we analyze the influence of a strongly disordered porous media with a broad range of pore and throat size distributions in the evaporation process. Experimental data togheter with throat and pore size distributions were used to build and match the network model, allowing us to determine the porosimetric curve for the Clashac sandstone for different degrees of correlation. Also, the correlation length was obtained from the percolation theory. In our case study the evaporation process modeled was insensitive to the different degrees of correlation that might occur between pores and throats. In addition, it was observed that the evaporation pattern was the same for all analyzed networks above the correlation length.
RENORMALIZATION-GROUP INVESTIGATION OF THE S = 1 RANDOM ANTIFERROMAGNETIC HEISENBERG CHAIN
Authors: LAJKÓ PÉTER
Published: January 2007

We introduce variants of the Ma-Dasgupta renormalization-group (RG) approach for random quantum spin chains, in which the energy-scale is reduced by decimation built on either perturbative or non-perturbative principles. In one non-perturbative version of the method, we require the exact invariance of the lowest gaps, while in a second class of perturbative Ma-Dasgupta techniques, different decimation rules are utilized. For the S = 1 random antiferromagnetic Heisenberg chain, both type of methods provide the same type of disorder dependent phase diagram, which is in agreement with density-matrix renormalization-group calculations and previous studies.
THE SCHWINGER MODEL ON A CIRCLE: RELATION BETWEEN PATH INTEGRAL AND HAMILTONIAN APPROACHES
Authors: AZAKOV S.
Published: January 2007

We solve the massless Schwinger model exactly in Hamiltonian formalism on a circle. We construct physical states explicitly and discuss the role of the spectral flow and nonperturbative vacua. Different thermodynamical correlation functions are calculated and after performing the analytical continuation are compared with the corresponding expressions obtained for the Schwinger model on the torus in Euclidean path integral formalism obtained before.
RELATION BETWEEN QUARK AND GLUON CONDENSATES FROM QCD SUM RULES
Authors: AFONIN S. S.
Published: January 2007

It is shown that QCD sum rules in the planar limit lead to a certain relation between four important quantities: ρ-meson mass, weak π-meson decay constant, quark and gluon condensates. As a byproduct an explanation for the dominance of ρρ-decay for the f0(1370)-meson is proposed.
SCALING APPROACH TO ANOMALOUS SURFACE ROUGHENING OF THE (d+1)-DIMENSIONAL MOLECULAR-BEAM EPITAXY GROWTH EQUATIONS
Authors: XIA HUI , TANG GANG , HAN KUI , HAO DA-PENG , CHEN HUA , ZHANG LEI-MING
Published: January 2007

To determine anomalous dynamic scaling of continuum growth equations, López12 proposed an analytical approach, which is based on the scaling analysis introduced by Hentschel and Family.15 In this work, we generalize this scaling analysis to the (d+1)-dimensional molecular-beam epitaxy equations to determine their anomalous dynamic scaling. The growth equations studied here include the linear molecular-beam epitaxy (LMBE) and Lai–Das Sarma–Villain (LDV). We find that both the LMBE and LDV equations, when the substrate dimension d>2, correspond to a standard Family–Vicsek scaling, however, when d<2, exhibit anomalous dynamic roughening of the local fluctuations of the growth height. When the growth equations exhibit anomalous dynamic scaling, we obtain the local roughness exponents by using scaling relation α loc =α-zκ, which are consistent with the corresponding numerical results.
ON THE EQUIVALENCE OF STABLE AND UNSTABLE FORMS OF THE INVERSE CIRCULAR HARMONIC TRANSFORM SOLUTION FOR THE RADON TRANSFORM
Authors: HAWKINS WILLIAM G.
Published: January 2007

We investigate the inversion of the 2D Radon transform with the technique based on the Circular Harmonic Transform (CHT) using Chebyshev/Zernike polynomials. This polynomial pair is often described as a solution of the unstable or causal form of the CHT inverse. The primary object of this work is to show analytically and explicitly that the polynomial pair is formally a solution to the stable form of the CHT inverse. Hence it is the first solution of its type to be simultaneously a solution to both forms of the inverse. The stable/unstable dichotomy is not fundamental to the CHT inverse. We validate this claim with numerical experiments and image data. We describe a potential application of the algorithm to MRI imaging with nonlinear gradients.
MAGNETIC RESONANCE (MR) IMAGE ANALYSIS — A STATISTICAL APPROACH
Authors: LEI TIANHU , WEHRLI FELIX W.
Published: January 2007

Following the rapid advance in applications of Magnetic Resonance (MR) imaging, there is an upsurge in contemporary image analysis. Image analysis techniques are implemented in different ways in the various frameworks of image processing. This paper proposes a new statistical approach. It first analyzes statistical properties of MR data (bulk magnetizations, MR signals, and k-space samples); then based on these statistics and through MR image reconstruction, derives statistical properties of MR image (a single pixel, any two pixels, and a group of pixels — i.e. an image region); finally by using these image statistics establishes a new stochastic image model (the correlated Finite Normal Mixture (cFNM)) and develops a new statistical image analysis method (the extended Expectation-Maximization (eEM) algorithm). The results obtained by using this cFNM-eEM framework demonstrate promise. The novel feature of this approach is that it eliminates heuristic assumptions and ad-hoc conditions in currently employed image analysis techniques and therefore leads to more accurate image analysis results. Although this approach is developed for the conventional MRI, but, following the same strategy and with some modifications, it can be extended to more advanced MRI protocols and other medical imaging modalities.
DYNAMIC EXTRACTION FOR VOI FROM CT IMAGES BASED ON VOLUME RENDERING
Authors: TIAN YUN , HAO CHONGYANG , WANG YI , HE GUIQING , WEI JUN , ZHAO HAITIAO , ZHAO BENHUA
Published: January 2007

The paper developed an approach to extract the VOI (Volume of Interest) from a CT dataset based on volume rendering, which can get a rough VOI from the volumetric data by simply adjusting the Window Level and the Window Width, then enhances the contrast among the voxels according to the Linear General Fuzzy Operator (LGFO) and extracts a desired structure from the above-mentioned enhanced 3D data through the feature function in rapid sequence; Our method adjusts the parameters according to the condition until the satisfied VOI is extracted. Experimental results show that the method combined with multi-manner can extract the VOI which represents clearly three dimensional anatomical structure of the object, such as tumors or normal organs, and can find potential applications in diagnosis and education.
The 4th international workshop on multimedia data mining (MDM/KDD2003)
Authors: Petrushin Valery A. , Kao Anne , Khan Latifur
Published: January 2007

In this short report we provide a summary of the presentations, conclusions and directions of future work that were discussed during MDM/KDD2003 workshop, held in conjunction with the 9th ACM SIGKDD International conference on Knowledge Discovery and Data Mining, August 27, 2003 at Washington, DC, USA.
Load balancing in homogeneous broadcast distributed systems
Authors: Livny Miron , Melman Myron
Published: January 2007

Three different load balancing algorithms for distributed systems that consist of a number of identical processors and a CSMA communication system are presented in this paper. Some of the properties of a multi-resource system and the balancing process are demonstrated by an analytic model. Simulation is used as a mean for studying the interdependency between the parameters of the distributed system and the behaviour of the balancing algorithm. The results of this study shed light on the characteristics of the load balancing process.
On the design of an expert help system for computer algebra systems
Authors: dos Santos R. P. , Roque W. L.
Published: January 2007

REDUCE[2, 3], like many modern Computer Algebra Systems (CAS) (MACSYMA, MATHEMATICA, MAPLE, SCRATCHPAD to name a few), embodies a large amount of mathematical knowledge which is spread out through thousands of procedures in the source code of the system. Most of this knowledge is, however, in an
implicit
form almost inaccessible to the user, who would have to decipher the source files to recover it. Also, to profit from it one needs to know in addition the capabilities of these computing systems and how to operate them.
Stewart varieties: a direct algebraic model for Stewart platforms
Authors: Dedieu J.-P. , Norton G.
Published: January 2007

We present a new approach to modelling a triangular Stewart platform, which we regard as defining an octahedron. The lines joining the unlinked articulation points correspond to the diagonals of the octahedron. Using a classical determinant identity, we show that the squares on the diagonals satisfy a rather special system of non-linear algebraic equations. A set of bounded solutions (the "Stewart variety") easily yields the coordinates of a platform. In fact, each solution gives two platforms, which are symmetric with respect to the base plane. Using Newton's method, we give an effective algorithm to calculate the Stewart variety and the corresponding platform coordinates. We conclude with the algorithm at work on two examples.
The standards factor
Authors: Billingsley Pat
Published: January 2007

This year at CHI'90, Karen Rafnel of Texas Instruments and I hosted a Special Interest Group (SIG) meeting entitled "User Interface Standards for Windowing Systems". The session was very well attended, with at least 200 people present, and there was a high level of interaction among the participants. I interpret this degree of involvement to indicate considerable interest in this topic among SIGCHI members overall, or at least a lot of curiosity about what's going on.
Exploratory behaviors and the design of computer instruction manuals in hypertext
Authors: Dufresne Aude , Tremblay Isabelle , Turcotte Sylvie
Published: January 2007

This study explores the problem of designing an environment for the learning of procedures using an hypertext environment. It presents an HYPERCARD interface for the learning of database procedures for the EXCEL spreadsheet. Direct manipulation interfaces (Shneiderman, 1982) encourage exploration and learning, but are not very effective for complex and abstract applications, which require planning and the coordination of many operations. For these interfaces, written documentation and help features are generally too fragmented and static. As for rigid tutorials they prove ineffective for the learning of complex procedures, as they leave no room for inferences. We will discuss the design of a learning environment to encourage and support exploration in this context. The system is based on a protocol analysis of users reading the written documentation and trying the system. Semantic, syntactic and process analyses have shown how users build their representations of the procedures to be learned (lexical ambiguities, inversion of sequences, search for illustrations, etc.). Based on this user model and drawing from studies on learning, a new environment was developed in Hypercard which put forward an interactional structure for the learning of direct manipulation procedures. Inspired both by the G.O.M.S. model (Card, Newell and Moran, 1983) and by "planning interfaces" (Miller, 1982), it first presents the hierarchy of goals, then outlines methods with accessible definitions, examples, exercises and various tests. Only there after these are alternative methods and selection rules explained. As in "planning interfaces", the system offers explanation both at the general level of goals and methods and at the concrete level of their integration into concrete examples. The user is free to explore this "training wheel" environment, where aspects of the Excel environment are simulated and gradually made accessible, with appropriate guidance and feedback.
Task-Aware user interfaces
Authors: Pavlin Jasmina
Published: January 2007

While the demand for computer systems that are more and more complex in terms of size and variety of applications is steadily increasing, design support tools and abstraction mechanisms for such systems are lagging badly behind. This places an increased burden on users and software developers alike. We believe that making the knowledge about the user's tasks and about the system's functionality explicit can reduce this burden significantly.
Teaching user interface development to software engineering and computer science majors
Authors: Perlman Gary
Published: January 2007

There is a critical need for timely and usable curriculum development materials for teaching user interface development to software engineering and computer science students. An updated version of the Software Engineering Institute's curriculum module on User Interface Development has been released. This paper provides an overview of the module, its history, and how it has been used.At the Software Engineering Institute (SEI) at Carnegie-Mellon University there is a Curriculum Development Project as part of the Education Program (Gibbs, 1989). A major goal of the curriculum development project is to devise model curricula and support-materials for teaching all topics in software engineering. For topics such as unit testing, software design, requirements analysis, and so on, there are curriculum modules to help teachers prepare courses. I have written, and recently revised, a module on User Interface Development (Perlman, 1989b), described in detail below. It has proven to be useful to all people interested in the teaching of user interface development to software engineers. Some of my experiences with the module are summarized in Perlman (1988).The module is
not
a book nor a course, but contains information to help others prepare short- or full-term courses on user interface development.
Key issues in HCI curriculum design
Authors: Preece J. , Keller Laurie
Published: January 2007

This paper reports on key issues that needed to be resolved in developing a large postgraduate distance education course in human-computer interaction intended for practicing software developers and technical managers.The multi-disciplinary nature of HCI is identified as being highly controversial when deciding what to teach and how. Questions about the balance of theory verses practice and providing tools verses knowledge are also considered major issues. A less general set of issues including questions such as what is design are also considered. Here, many of the sources of controversy can be traced to higher level issues, in particular the multi-disciplinary nature of HCI.
An iconic description language: programming support for data structure visualization
Authors: Seminar Kudang B. , Robson Robert N.
Published: January 2007

An icon description language, named DSIL (Data Structure Iconic Language), is described which facilitates the design of icons depicting data structures and accelerates the development of iconic interfacing tools for program visualization and debugging. By using the DSIL, different users can define or redefine their own icons to satisfy their needs. The DSIL has features of modern programming languages. It is hierarchical, modular, and provides adoption (inheritance). The design of the DSIL is based on the features of data structures in MODULA-2. The implementation of the DSIL in a data structure editor is presented.
Design process and decision rationale models for the N-Chime interface system
Authors: Treu Sigfried , Peter Sanderson D. , Rozin Roman , Sharma Ravi
Published: January 2007

The
N-CHIME
interface system was designed with the broad objective of enabling, or "empowering," different types of users to carry out effective modeling and simulation applications with the Hierarchical Simulation Language (
HSL
). A design methodology was developed that is based on a "parallel processes" model: a triad of parallel design processes, one directed at each of the user, the interface, and the application. For comprehensive and systematic interface design, such a methodology is essential.
N-CHIME
has been implemented and tested. This paper presents an overview of the design models and some of the resulting tools and techniques supportive of the application-specific user. It also highlights the importance of providing online access to the design decision rationales that were used for the various user-visible tools and devices.
Book review: MAN-COMPUTER INTERFACES: AN INTRODUCTION TO SOFTWARE DESIGN AND IMPLEMENTATION by R. B. Coats & I. Vlaeminke (Blackwell: 1987)
Authors: Carey Tom
Published: January 2007

It's time once again to choose a textbook for fall classes. We have had several quality texts for a number of years---I myself have used Rubenstein & Hersh, Norman & Draper and Shneiderman, and I know other colleagues with alternate preferences. Several new books can now be added to the list of candidate texts for an HCI course. In this article, I review five recent offerings. The earliest dates from 1987 and the latest from 1989 (though the '87 text is from Britain and may not be familiar to North American instructors).
BOOK REVIEWS
Authors: Carey Tom
Published: January 2007

From the cover: "This book provides an introduction to the basic concepts and facilities of text-based interfaces. The major underlying theme is that in any system, the interface software can be identified as a distinct element separate from the task processing. The book illustrates how this separation can be achieved and how interface functions can be represented by general abstractions independent of the devices on which the system is to be implemented. Most chapters incorporate sets of discussion and programming exercises."
Book review: DESIGNING USER INTERFACES FOR SOFTWARE by Joseph S. Dumas (Prentice-Hall, 1988)
Authors: Carey Tom
Published: January 2007

From the cover: "The components of the user-software interface that the book is primarily concerned with are: the words and symbols that people see and read on a computer screen; the content and layout of displays; the procedures that people must use to enter, store, and display information; and the organizational structures of the interface as a whole. The goal is to help create better, more effective user interfaces. Help is found in the rules and guidelines described in this book."
Book review: USER INTERFACE DESIGN FOR COMPUTER SYSTEMS by Tony Rubin (Ellis Howard/Wiley: 1988)
Authors: Carey Tom
Published: January 2007

As you might expect by now, this text is again different from each of the others. Physically, it is the only hardcover in the lot---although the impact of binding on price or durability is not easy to determine. Parts of the book, like the Dumas volume, reflect practical experience and a deliberate choice of a restricted set of issues. Parts of the book contain numerous examples from existing software, like Brown & Cunningham, although focussing heavily on a single system (Apple's Macintosh).
A compendium of key search references
Authors: Aoe Jun-ichi
Published: January 2007

How to store and to search, or retrieve, information efficiently is an important problem in computer science because searching is the most time-consuming part of many programs, and the substitution of a good search method for a bad one often leads to a substantial increase in speed. Particularly, a key search technique of finding which record has a special field as its key has been widely used in database management, compiler construction, natural language processing, and many other applications. The aim of this article is to provide a great deal of references, classified by consideration of their problems.
Selected IR-Related Dissertation Abstracts
Authors: Humphrey Susanne M.
Published: January 2007

The following are citations selected by title and abstract as being related to Information Retrieval (IR), resulting from a computer search, using Dialog Information Services, of the Dissertation Abstracts Online database produced by University Microfilms International (UMI). Included are UMI order number, title, author, degree, year, institution; number of pages, one or more Dissertation Abstracts International (DAI) subject descriptors chosen by the author, and abstract. Unless otherwise specified, paper or microform copies of dissertations may be ordered from University Microfilms International, Dissertation Copies, Post Office Box 1764, Ann Arbor, MI 48106; telephone for U.S. (except Michigan, Hawaii, Alaska): 1-800-521-3042, for Canada: 1-800-268-6090. Price lists and other ordering and shipping information are in the introduction to the published DAI. An alternate source for copies is sometimes provided. Dissertation titles and abstracts contained here are published with permission of University Microfilms International, publishers of Dissertation Abstracts International (copyright by University Microfilms International), and may not be reproduced without their prior permission.
Challenges in obtaining peak parallel performance with a convex C240, a parallel vector processor
Authors: McGehearty Patrick
Published: January 2007

The behavior of the Linpack 300x300 benchmark is examined in the context of a parallel vector machine architecture. Detailed evaluation is performed with respect to the Convex C240. Issues relating to algorithm design and system characteristics are discussed in the context of the Linpack implementation.
Scientific visualization of performance data: evaluation of
DV-Draw
Authors: Gaither Blaine
Published: January 2007

This report discusses the attributes of the
DV-Draw
package from the VI Corporation of Amherst, Massachusetts.
DV-Draw
is a scientific visualization package which is part of a larger package called DataViews. The requirements for visualization software in performance evaluation are identified. The results of applying
DV-Draw
to animate the output of an architectural model were successful.
Book Review: Philosophy, Mind, and Cognitive Inquiry Edited by David J. Cole, James H. Fetzer, and Terry L. Rankin (Kluwer Academic Publishers)
Authors: Firschein Oscar
Published: January 2007

This book is an anthology of papers concerned with philosophical and theoretical issues in the nature of mind and mental processes. The purpose of the collection is to provide readers with representative work by leading philosophers working on problems in cognition and the nature of the mind. The papers range in date from 1978 to 1989. The book begins with a quotation from McCarthy:Artificial Intelligence cannot avoid philosophy. If a computer program is to behave intelligently in the real world, it must be provided with some kind of framework into which to fit particular facts it is told or discovers. ... I agree with philosophers who advocate the study of philosophy and claim that one who purports to ignore it is merely condemning himself to a naive philosophy.
Book review: Object-Oriented Simulation with Hierarchical, Modular Models by Bernard P. Zeigler (Academic Press)
Authors: Benner Kevin
Published: January 2007

Bernard Zeigler's book, titled "Object-Oriented Simulation with Hierarchical, Modular Models" and subtitled "Intelligent Agents and Endomorphic Systems", will be most valuable to individuals interested in model development to support simulation within an object oriented environment. This book may be easily read by people not familiar with the simulation literature or Zeigler's previous work. Ideally one should have some familiarity with the basic notions of object oriented design or programming, but even that is not really necessary. This review will summarize the work presented in this book and then conclude with a short critique with regard to the authors stated objective, to make accessible to broad audience "... the concepts of reusable, multifacetted, multi-abstraction, model bases and endomorphic systems".
Book review: Machine Vision: Algorithms,Architectures, and Systems. Edited by Herbert Freeman (Academic Press)
Authors: Moore Scan
Published: January 2007

Machine vision has been a productive area of research in artificial intelligence and has had some success in industrial applications, but the machine vision community is dissatisfied with the rate of progress with which computerized vision systems have been utilized in industry as well as in society at large. In order to better define the issues and explore future directions, the Center for Computer Aids for Industrial Productivity (CAIP) at Rutgers University organized a workshop in April, 1987 for machine visionists in both academia and industry. From this workshop, Herbert Freeman, the director of CAIP, has compiled a selection of papers and notes from panels and forums into a coherent presentation of the workshop. This collection gives the reader both the academic and the industrial perspective on the state-of-the-art and the immediate future of machine vision.
A simulation method for multi-level data security analysis
Authors: Burris Harrison R.
Published: January 2007

A simulation methodology is presented for partitioning data sets of a sensitive data processing system into multi-level security classes according to a ranking of the resulting value to the system's opponents if the security of each data set were compromised. The value of the compromised data sets is determined by using a game-theoretic approach which simulates the environment in which the system under design operates. The same methodology determines the overall level of security achieved by a particular partitioning of the data sets. The methodology is applicable throughout the system life cycle.
A heuristic teleprocessing network design technique
Authors: Livings Harold E. , Pooch Udo W.
Published: January 2007

A technique is presented for designing teleprocessing networks on the basis of weighted heuristic partitions of the network nodes. The partitions group the nodes on the basis of common internodal design characteristics related to traffic flow, geographical location, delay and reliability requirements. Weights incorporated into the partition selection process permit adaptive adjustment of the design system based on actual experience gained in designing networks.
Workload classification
Authors: Artis H. P. , Paulhamus R. E.
Published: January 2007

Workload classification is a methodology which allows the analyst to describe the workload of a computer system with a minimum number of job classes. This technique reduces the effort required to produce models of a system. This could involve verification of actual systems or simulation of proposed configurations. Particular areas of interest include:

- cluster analysis techniques

- analysis of batch systems

- analysis of real time systems

- applications with simulation models.

The authors primary area of interest is in large commercial production oriented environments with both batch and real time applications.
Relationship of software engineering and simulation
Authors: Baas Elwood , Ellis James
Published: January 2007

In response to the enormous annual dollar value spent on software, major emphasis is being placed within industry, Government and academia on the establishment of a rigorous discipline for the development of software—i. e., on the establishment of software engineering. This has significance in the realm of computer system simulation for two basic reasons: first, computer system simulation (any simulation for that matter) does itself involve the development of software; and second, computer system simulation is a technique/tool which can be applied to the discipline of software development. It will be the purpose of this workshop to discuss both the role of software engineering in computer system simulation and the role of computer system simulation in software engineering. Potential topics for discussion include, but are not limited to:

a. Identification of software engineering

b. Disciplines required for software engineering

c. Software engineering in support of computer system simulation

d. Computer system simulation as a tool in software engineering

e. Recent progress in the direction of establishing the software engineering discipline.
Experience with trace driven modeling
Authors: Noetzel A. S. , Herring L. A.
Published: January 2007

Trace-driven modeling is a technique for optimizing a computer system by simulation studies, in which the job load data required by the simulator is taken directly from the existing system. Its advantages are 1) a full statistical representation of the job load, 2) potentially more accurate, system-independent and relevant data, and 3) the possibility of wider-ranging simulation studies without the necessity of collecting more particular data.

The variations of the trace-driven modeling technique that have occurred in practice are summarized. The above advantages of the technique and their limitations are then analyzed in the context of experience with it for the evaluation of a class of scheduling algorithms for an interactive system on the CDC 6400. Results of simulations showing the effects of interdependence of resource demand parameters are presented.
Run-time characteristics of a simulation model
Authors: Gehringer Edward F. , Schwetman Herbert D.
Published: January 2007

This paper compares the efficiency of trace-driven simulation models of computer systems with the efficiency of function driven models. In a trace-driven model (TDM), the next service request for a task is selected from a file of requests which was created earlier, often from data derived from a functioning system. This can be compared to a function-driven model (FDM), in which the next service request is selected using generation techniques based on random deviates. While both kinds of models can produce statistically accurate results, a TDM is thought to be inherently more accurate, but it has been suspected that a FDM is faster.

The comparison of these two techniques is based on a simulation model of a computer system which has been specially constructed so as to operate either as a TDM or an FDM. The key feature of the study is that by using this model, we have isolated the demand-generation technique (either trace-driven or function-driven) as the single factor affecting performance of the model. A run-time program monitor and a software-monitor event probe are used to evaluate the resources used by various runs of the two kinds of simulation models. The results indicate that, contrary to earlier expectations, the performance of both techniques is comparable. We also demonstrate the effects of various block sizes on the performance of the TDM and the effects of the complexity of the request functions on the performance of the FDM.
Management of a large computer network simulation project
Authors: Segal Ronald , White Norman
Published: January 2007

As simulation technology matures, there is an increasing demand for the development of useful products within specified time and cost constraints. Hence, simulation studies must be managed and measured by the same criteria as other large projects. The project described in this paper, a behavioral study of a possible national computer network, requires the implementation of a large and complex simulation model. In order to manage better the many individuals and diverse groups contributing to the overall effort, many of the new advances in project management, software design, and programming technology have been adopted. The results of this effort tend to support the economies and efficiencies in programming, as well as improvements in reliability, usually claimed by advocates of these techniques. More significantly, these approaches make it possible to keep all participants active in overall project progress. They have also permitted a work segmentation that takes advantage of the variety of personnel available to the project.
A queuing model with discrete service speeds
Authors: Asai H. , Lee S. C.
Published: January 2007

An input source of the model is generated in accordance with a probability density function P
r
(n,t), where n and t are a spatial variable and a time variable, respectively. Thus the input arrives as a time-variable train. A queue consists of m blocks, and each block consists of a finite number of small waiting spaces. A single service facility is used in the model, and its service processing speed is a constant that is selected from several operational rates. The next higher operational speed and the next lower operational speed are twice as fast as and half as slow as the present constant speed, respectively. The service discipline is first-come-first-served.

When the needed queuing space exceeds the queuing space available, a congestion or input loss occurs. Minimizing such input loss with the least admissible queuing space and the slowest possible service speed is desirable. When the service facility is a machine, it may be easier and more economical to increase the service speed operations rather than to furnish a larger amount of queuing space.

The model is simulated on a digital computer. Two service Speed controls are examined in the simulation. The first is a deterministic control, and the second is a probabilistic control. In the former, when the amount of the queuing space available is almost consumed, the service speed is upgraded to the next higher rate. The speed remains at this rate until the amount of unused queuing space increases. Later, the speed is downgraded to the original rate. In the latter, control is switched probabilistically no matter what the queuing space may be but it can specify a service processing distribution among different speeds during a long time period.

The simulated results or the probability of congestion P
e
with various queuing space lengths and service speeds is presented. This information may be useful for understanding input loss phenomena as well as for designing an efficient low-cost queuing system.
Program testing techniques using simulated execution
Authors: Osterweil Leon J. , Fosdick Lloyd D.
Published: January 2007

Simulation is proving to be a valuable technique in testing computer programs. By simulating different aspects of a program's execution and structure it is possible to detect errors and sometimes demonstrate the absence of certain errors in the program. This presentation will explore three popular testing methodologies which employ simulation techniques. Each methodology is based upon a different type of simulation of the program. The differences in error detection capability resulting from these different choices of simulated execution will be examined. Finally a method for using the best characteristics of each technique in a general validation system will be presented.
A note on Fortran 90 source form
Authors: Meissner L. P.
Published: January 2007

Text prepared in accordance with the following rules (which are adapted from X3J3 S8.115, June 1990) is compatible with both the fixed source form and the free source form of Fortran 90. In particular, such text could appear in a file that is intended for possible reference from
include
lines in either fixed form or free form program units.
The Fortran (not the foresight) Saga: the light and the dark
Authors: Meek Brian
Published: January 2007

Week by week we read about corporate battles for shares in a market, be it hardware, software or services, about takeover manoeuvrings and buyouts, about rival consortia seeking to dominate areas like Unix or networking. Yet these ongoing stories, hard though they may sometimes be to follow, have the complexity of a Ladybird book, compared with the long-running saga of the Fortran 8X standard.
A new placement level wirability estimate with measurements
Authors: Meyer Steve
Published: January 2007

An extension of the wirability estimate concept to master slice placement is presented. This estimate is usable on individual circuits, produces detailed wire requirement maps, but requires target designs to be at least partially placed. The main innovation is the discovery of an outer rectangle estimate that separates basic wire requirements from routing details. The estimate averages wires within one chip but is inapplicable to chip type wire space modeling. Steiner tree net decomposition, the half perimeter wire length estimate, and potential wire requirement reduction from a third metal layer are evaluated.
Hardware and software tools for the development of a micro-programmed microprocessor
Authors: Nash James , Spak Mike
Published: January 2007

This paper discusses the development and implementation of a number of hardware and software tools used in the design, development, and debugging of the microcode and nanocode for the MC68000 microprocessor. A functional description of these tools is included as well as an analysis of how each worked with respect to solving the desired problem (ie., generating correct microcode and nanocode). Peculiarities in the integrated circuit industry for microcode verification is considered as well as the automated process of error detection and correction.
On fundamentals of computer-aided design of firmware
Authors: Hansen Igor , Leszczylowski Jacek
Published: January 2007

A real-time model of microprogrammed hardware is described. It is used for firmware classification and for stating the conditions under which an equivalent discrete-time model can be introduced. We also give a brief description of a computer-aided firmware design system, which was based on these models.
Heuristics for the global optimization of microprograms
Authors: Poe Michael D.
Published: January 2007

Most of the discussion in the microprogram optimization literature deals only with straight line segments. This paper discusses an implementation in progress that globally optimizes microprograms. The complete optimization of microprograms has been shown to be very expensive computationally. However, the use of heuristics, such as those described in this paper, can efficiently approximate exhaustive optimization of microprograms.
The derivation of microcode by symbolic execution
Authors: Ulrich John Wade
Published: January 2007

Given a description of a computer called the “target” and a micro processor called the “host” we would like to generate a micro program which when executed by the host will simulate the target. We accomplish this by first breaking the target down into a set of small segments. Then, logical conditions for an appropriate microcode are generated for each segment by a combination of symbolic execution and simplification. When completed, the segments are assembled into a working code by solving the set of logical conditions.
Formalization and automated synthesis of microprograms
Authors: Mueller R. A.
Published: January 2007

The problem of automating the production of reliable micro-code is addressed. In contrast to validation and verification approaches which attempt to establish the correctness (incorrectness) of manually produced code with respect to a set of specifications, the automated synthesis approach attempts to systematically derive the code directly from the specifications.

Formal representations of both microprogrammable machines and image machine instruction set requirement specifications are discussed, as is a formal semantic characterization of microprogram execution with respect to the given representations. The microprogram synthesis process is viewed as a special kind of theorem-proving process which attempts to prove the existence of a computation satisfying a requirement specification for a given machine, and when successful, extracts a corresponding microprogram directly from the proof. The NP-completeness of the problem leads to the necessity for effective heuristics, particularly when dealing with horizontal machines.
The economics of programmable system components
Authors: Cragon Harvey G.
Published: January 2007

Integrated circuits having complexity levels approaching one million devices per chip (VLSI) present significant problems in the cost of design and use. There are advocates for very capable design automation techniques coupled with rapid turnaround front ends as the path to VLSI. Others advocate the use of programmable devices such as microcomputers and gate arrays. This paper presents cost models for these two approaches which demonstrate that the Programmable System Component (PSC) approach is the only viable path in VLSI. This paper will also describe a set of generic PSCs which will meet the needs of 70%-80% of the sockets, and perhaps 95% of the production volume for VLSI components. The remaining 20%-30% of the sockets and 5% of the volume will be served by specific, nonprogrammable designs.
Development tools for user microprogramming
Authors: Geyer Steven , Lake Anthony
Published: January 2007

Software tools used to develop microcode for the BBN Microprogrammable Building Block have been implemented using standard software engineering and language development utilities. The major microcode development tools include a microassembler, multi-task operating system, and debugging packages. Important aspects of these and other development tools are the functional, user interface and structural characteristics.
Issues of the design of a low level microprogramming language for global microcode compaction
Authors: Poe Michael D. , Goodell Ross , Steely Simon
Published: January 2007

Microcode compaction, or packing, is the process of assigning microoperations to microwords so that the minimum number of microwords and execution time is used by the microprogram. The techniques for global microcode compaction have been described elsewhere (see below). This paper describes a proposal for an intermediate level language approach to compilation which allows machine independent global compaction. We will call the program which does this compaction the packer. This work comes from the development of the V-Compiler, a retargetable microprogram generation system
1
. The goal is to be able to produce very high quality microcode, while allowing code manipulations to be described and performed in an orderly manner.
Microarchitecture description techniques
Authors: Gieser John L. , Sheraga Robert J.
Published: January 2007

A procedure is outlined for describing the microarchitecture of a horizontal processor such that a retargetable Microprogram Compiler System can incorporate the description to generate microcode for that processor. The microarchitecture description methodology is an organized approach to defining a machine's microinstruction formats, fields, and microorders; its hardware elements; its microoperation usage rules; and its behavioral rules. To a large extent, the description procedure can be performed interactively. The link between the microarchitecture description and the microprogram compiler, termed the instruction set interpretation mechanism, is also described. Preliminary application of the microarchitecture description methodology to several real processors has shown that, despite some problems, the procedure shows promise for significantly reducing the time required to retarget a microprogram compiler.
MDS
Authors: Takahashi Kazutoshi , Takahashi Etsuo , Bito Tatsushige , Aoyama Toshinori , Yamada Akihiko
Published: January 2007

A general purpose, total system MDS
1,2
(Microprogramming Design-support System) has been developed to hasten the introduction of various kinds of firmware over the widest possible range of computer from the largest to the smallest (microcomputer).

Not only many types of assembly language but also machine dependent high-level languages can be used and physical address assignment can be performed automatically with MDS.

This paper describes an overview of MDS, the design approach to the high-level languages, and three examples which have been developed.
The “cultures” of microprogramming
Authors: Tredennick Nick
Published: January 2007

I discuss four “cultures” of microprogramming. I call them: the Commercial Machine Culture, the Bit-Slice Culture, the Microprogrammable Machine Culture, and the Single-Chip Culture. Commonly used microprogramming terms mean different things to people from different cultures. I define the cultures and then contrast some microprogramming folklore with realities from my culture (the Single-Chip Culture). When you read or hear statements about microprogramming, know which culture is speaking. I hope discrepancies between some folklore and reality in the single-chip case will convince you it's important.
Control schemes for VLSI microprocessors
Authors: Burke Gary R.
Published: January 2007

As microprocessors move into the VLSI era, the number and complexity of the functions they are expected to perform increases beyond the capability of conventional control schemes. This paper discusses the fundamental requirements of such a control system, and explores the possibility of using external microcode control.
A microsequencer architecture with firmware support for modular microprogramming
Authors: Papachristou Christos A. , Gambhir Satnam Sing
Published: January 2007

The aim of this paper is to propose a microsequencer architecture and supporting firmware that are suitable for implementing modular microprogramming. The structure consists of a PLA sequencer store, a microcode store (memory) and an address processor. The latter, operating under sequencing commands issued by the PLA, generates the effective address for both stores. The supporting firmware primitives or transactions, stored in PLA, are suitable for structured microprogramming constructs, e.g., while-do, if-then-else, etc. This capability is extended to complex sequencing structures which are then implemented by context-free transaction blocks. Such sequencing is required to achieve migration of complicated. software functions, such as operating systems, in firmware. It is expected that the proposed method is compatible with LSI/VLSI array technology.