bluuebunny/crossref_metadata_2025 huggingface dataset:
BOOK REVIEW: HUMAN-COMPUTER INTERACTION: A DESIGN GUIDE by Mark K. Jones (Educational Technology Publications, 1989.)
Authors: Tripp Steven
Published: January 2007

When reading a book about designing human-computer interaction, it adds to the reader's confidence if the book is well-written. After all, if someone claims to know something about "user-friendliness," his book should reflect some of the same kinds of considerations that go into software design. Happily, Mark Jones'
Human-Computer Interaction: A Design Guide
meets that criterion.
Video reviews: USER INTERFACE STRATEGIES '88
Authors: Carey Tom
Published: January 2007

For this review, the tapes were viewed by members of the Human-Computer Interaction Research Group at the University of Guelph. Some reviewers watched the whole series, some only one segment. Each segment was reviewed by at least two people. All the reviewers have competence in user interface design, but the reviewers saw both topics in which they had expertise and other areas with which they were not as familiar.
MCC HUMAN INTERFACE LABORATORY TECHNICAL REPORTS
Authors: Grudin Jonathan
Published: January 2007

The following are abstracts of non-proprietary Technical Reports available from MCC's Human Interface Laboratory. Requests for SINGLE copies may be sent to Janet Kilgore , MCC Human Interface Laboratory, PO Box 200195, Austin, TX 78720. Include your mail address, as copies cannot be distributed electronically.
EVA: an experimental video annotator for symbolic analysis of video data
Authors: Mackay W. E.
Published: January 2007

There is a joke about the man who has a map of the world ... with a scale of 1 mile to 1 mile. Sometimes video has the same character; it can be difficult to compress in useful ways. Sometimes you have to see all of it to understand any of it. Even so, the use of video as a research tool has been increasing rapidly, due partly to the reduction in equipment costs and partly to increased work in the areas of human factors and user interface design. This paper describes some of the issues surrounding capturing, recording, analyzing and presenting video data and describes a prototype system, called EVA, that is designed to address some of these issues.
Video in applied cognitive research for human-centered design
Authors: Roske-Hofstrand Renate J.
Published: January 2007

Video constitutes one of the most direct and contextually rich means for capturing observable behavior in human-computer interaction. However, a major shortfall of this type of visual medium lies in its failure to directly capture those aspects of user behavior that can predictably be associated with human cognition. Goal-directed cognitive user processes such as those that occur in problem-solving, decision-making, and planning activities are by their nature not subject to recording on camera. Traditionally, cognitive researchers have inferred user planning and intent structures by abstracting from relatively long sequences of behavioral cues captured by video protocols.
The role of the video professional in a research environment
Authors: Chow M. D.
Published: January 2007

The video professional that enters the research environment is likely to encounter both exhilarating resonances and boggling confusion at the hands of researchers. There will be situations when standard video practice exactly compliments the researchers' work. There will also be situations when it is necessary to break every rule held sacred by video practitioners. This paper is an attempt to outline some of the many ways in which the research scientist and the video professional can coexist productively. The focus will be on usage of video as a presentation tool.
Using video in the BNR usability lab
Authors: Kennedy S.
Published: January 2007

This paper describes the goals of the BNR Usability Lab and explains how we have achieved our goals by developing the "Co-Discovery Learning" testing methodology and designing "U-Test", a special interface for usability testing with video.
Video as an enabling technology for computer-supported cooperative work
Authors: Horton M. , Elwart-Keys M. , Kass R.
Published: January 2007

Research at the Center for Machine Intelligence (CMI) focuses on computer-based methods for supporting cooperative work between members of large organizations. To this end, we are exploring how video technology can be used as a multi-purpose tool, not only to study the collaborative work that occurs in our electronic meeting room, the Capture Lab, but also to support the activities of the room's users. We first briefly describe the Capture Lab and the facilities available for recording activities that occur in the room. We then discuss how these facilities can be used to create an "audit trail" for crucial decisions made in meetings. The next section describes ways to use videotape in conjunction with a tool for coding interpersonal behavior to provide a group with feedback about its interaction. Finally, we illustrate how video is a critical tool in assessing the effectiveness and impact of new technologies, such as the Capture Lab, for group work.
Using video-based observation to shape the design of a new technology
Authors: Tatar Deborah
Published: January 2007

A common problem in the development of software is that the designers either overlook certain aspects of the users' situations or do not have access to them. Not all projects are plagued by this kind of oversight, but it is widespread in the development of single-user systems and is compounded when we turn to systems designed to support collaborative work.
Programming expert systems at the K-tree level
Authors: Kiernam G. , Koltun A. , Schwartz E.
Published: January 2007

In working with the construction of expert systems over the past several years we have had two main goals: the development of useful expert system applications and the development of general methods for designing and implementing expert system applications. We have described how K-Trees were used to construct an expert system for advising mathematics and computer science majors about course selection. [1] More recent work on a new expert system has shown that the K-Tree method is a general design and programming technique that can be extended to work with applications involving reasoning with uncertainty.
Transformation approach for consistency in object-oriented knowledge bases
Authors: Yao Hsin-Hsen , Kim Hwa Soo
Published: January 2007

A knowledge base is
consistent
if all its data, information, or knowledge (regardless they are stored in database or implied by inference engine) satisfy the predefined constraints which represent a real world rules or restrictions. Maintaining knowledge consistency in an object-oriented knowledge base is difficult since (i) two data items in the knowledge base may have the relationship that is not explicitly represented by the inheritance; and (ii) logic programming trends to manipulate "flat" data. In contrast, it is easier to develp a mechanism for maintaining the consistency in a value-oriented system (e.g., relational database or logic programming) [Ullm87].
Summary of changes to Fortran draft
Authors: Adams Jeanne C. , Wagener Jerrold L.
Published: January 2007

In response to comments received from public review of the first draft proposed Fortran standard (X3J3/S8.104), a number of changes have been made and a revised draft proposed standard (X3J3/S8.112) has now been released for further public review. The following outline summarizes the technical changes that were made on the basis of the first review. A rationale for the major changes is also presented.
Partial-record input and output
Authors: Meissner Loren P.
Published: January 2007

The record-oriented nature of Fortran I/O has long been recognized as an anachronism. Most other programming languages permit processing to stop in the middle of an input or output record, and to continue later with the remainder of the same record. "Stream access" appeared in the public review draft of the Fortran 77 standard, but was finally removed because of inconsistencies. A partial-record input and output facility was added to the Fortran 88 draft at X3J3 meeting 111 (February 1989) and was further refined at meeting 112 (May 1989).
A program for computing the Liapunov functions and Liapunov constants in scratchpad II
Authors: Wang D.
Published: January 2007

This report describes the implementation and use of a program for computing the Liapunov functions and Liapunov constants for a class of differential systems in Scratchpad II.
Speed and data structures in computer algebra systems
Authors: Fateman R. J. , Ponder C. G.
Published: January 2007

Comparing the speed of computation in algebra systems is a perennial occupation of system designers, algorithm implementors, and, more recently, marketing personnel. At least some people have observed that for many problems, the choice of a system makes much less difference than the approach used to represent the problem. The mapping from mathematics to a data representation and the choice of algorithms can make significant, and separate, contributions to efficiency. Systems which have the flexibility to provide several data structures and algorithms can provide an advantage in this respect. Macsyma [1] is probably the system with the largest selection, currently. On the other hand, Macsyma has not taken advantage of recent advances such as the extensive use of hash-coding incorporated in the University of Waterloo's Maple [2] system. For the one somewhat artificial benchmark we discuss in this paper, it appears that the Maple system does considerably better than any representation in Macsyma by precisely this mechanism.
An investigation of the performance of a distributed functional digital simulator
Authors: Chawla P. , Carter H. W.
Published: January 2007

The increased use of Hardware Description Languages (HDLs) in the process of designing digital systems has spawned an increased interest in the development of simulation systems for these HDLs. Unfortunately, the size and complexity of most contemporary digital systems is such that obtaining meaningful HDL simulation results may require days or even weeks of processing time. Thus, there is a growing need to speed-up the HDL simulation of digital systems at all levels of design abstractions. One promising approach is to depart from the von Neuman style of computation and use a general-purpose mutiprocessor system to simulate digital systems. As part of the research supported by SIGDA/DATC Design Automation Graduate Scholarship, we implemented a prototype distributed multi-level functional HDL simulator. The technique that we use to speed-up simulation is based on the
Virtual Time algorithm.
Understanding selective assignment
Authors: Brown J. A. , Hawks B.
Published: January 2007

This paper discuses the rules for evaluating expressions on the left of an assignment arrow and shows that ordinary assignment and vector assignment are just special cases of selective assignment. This unification of the three kinds of assignment expressions represents consistent and proper extensions that could be added to any future
APL
2 implementations.
Implementation of predicate logic in APL2
Authors: Engelmann U. , Gerneth Th. , Meinzer H. P.
Published: January 2007

Our aim is the implementation of a knowledge based image analysis system, which combines the capabilities of APL and Artificial Intelligence. The first step is the implementation of predicate logic in APL, based on the suggestions of Brown. A first prototype is now ready, which can be used for PROLOG-like functions in connection with image processing functions.
Data typing in APL
Authors: Livingstone D. , Gharib H.
Published: January 2007

This paper describes a form of data typing implemented in APL. By contrast with conventional data typing, which basically specifies a storage format for a data type, it is a means of specifying the set of logical values that a variable is to be permitted to take. To assign a data type, a new copula analogous to value-assign is used. Hence only a single new symbol is added to APL, not a whole data typing sublanguage, but the full power of APL is available to define a type.The objectives and overall design of the data typing are described, plus an overview of its usefulness in writing application software.
Techniques for avoiding conditional execute in APL2
Authors: Mansour S. M.
Published: January 2007

Execute ( ) is unique among the APL2 primitive functions in that it is the only one which does not necessarily produce an explicit result. This makes it convenient for executing an APL expression conditionally. Execute is also unique in that it is the only symbolic primitive which permits only a character argument. This tends to produce awkward programming.This paper will look at ways to avoid the use of conditional execute by suggesting alternate methods and ways of thinking which are unique to APL. These methods have been used to great advantage in production code.Most examples of code used in this paper have been taken from an actual APL2 application. Although most of the examples are in APL2, many will work in other APL dialects. Some minor modifications have been made to the code in the interests of security and clarity. Most of these involved changing the names of some functions or variables.
Using APL2 in statistics
Authors: Sykes A. M. , Hawkes A. G.
Published: January 2007

The use of APL by professional statisticians is certainly one of the growth areas of APL users in Britain. The increasingly available second generation APL interpreters offer extra facilities that make it an even more attractive language for the jobbing statistician. In this paper, we present ways of using nested arrays and defined operators that are particularly suited to many commonly occurring problems in Statistics.
A neural network for probabilistic information retrieval
Authors: Kwok K. L.
Published: January 2007

This paper demonstrates how a neural network may be constructed, together with learning algorithms and modes of operation, that will provide retrieval effectiveness similar to that of the probabilistic indexing and retrieval model based on single terms as document components.
Integrated information retrieval in a knowledge worker support system
Authors: McAlpine G. , Ingwersen P.
Published: January 2007

This paper describes the design of the information retrieval facilities of an integrated information system called EUROMATH. EUROMATH is an example of a
Knowledge Worker Support System:
it has been designed specifically to support mathematicians in their research work. EUROMATH is required to provide uniform retrieval facilities for searching in a user's personal data, in a shared database of
structured
documents and in public, bibliographic databases. The design of information retrieval facilities that satisfy these and other requirements posed several interesting design issues regarding the integration of various retrieval techniques. As well as a uniform query language, designed to be highly usable by the target user group, the retrieval facilities provide
expert intermediary
functions, i.e. sophisticated support for the retrieval of bibliographic data. This support is achieved using a model of the user, a model of the user's information need and a set of search strategies based on those used by human intermediaries. The expert intermediary facilities include extensive help facilities, automatic query reformulation and browsing of a variety of sources of query terms.
Towards an information logic
Authors: van Rijsbergen C. J.
Published: January 2007

'Probability is expectation founded upon partial knowledge.' (Boole, 1854)

Information retrieval based on stored program electronic computers has been an active area of research since the time these machines were invented. It is therefore somewhat surprising that even now no formal computational model for IR exists. There is no well-defined logic to describe information retrieval, and there is no proof or model theory to talk about the truths of IR.

This paper argues that much of the research work in the past has been steps in the direction of a logic for IR. These steps have been taken by developing formal models for information retrieval, but to date none of these are complete nor could any claim to be a computational model for IR. To appreciate this development I shall present a picture of IR, describing bits of a puzzle which may fit together to point to a new framework within which a computational model or logic could be described.
A parallel indexed algorithm for information retrieval
Authors: Stanfill C. , Thau R. , Waltz D.
Published: January 2007

In this paper we present a parallel document ranking algorithm suitable for use on databases of 1-1000 GB, resident on primary or secondary storage. The algorithm is based on inverted indexes, and has two advantages over a previously published parallel algorithm for retrieval based on signature files. First, it permits the employment of ranking strategies which cannot be easily implemented using signature files, specifically methods which depend on document-term weighting. Second, it permits the interactive searching of databases resident on secondary storage. The algorithm is evaluated via a mixture of analytic and simulation techniques, with a particular focus on how cost-effectiveness and efficiency change as the size of the database, number of processors, and cost of memory are altered. In particular, we find that if the ratio of the number of processors and/or disks to the size of the database is held constant, then the cost-effectiveness of the resulting system remains constant. Furthermore, for a given size of database, there is a number of processors which optimizes cost-effectiveness. Estimated response times are also presented. Using these methods, it appears that cost-effective interactive access to databases in the 100-1000 GB range can be achieved using current technology.
An optical system for full text search
Authors: Mitkas P. A. , Guilfoyle P. S.
Published: January 2007

In this paper we propose a full text search system based on optics. The storage and processing of the textual data are performed by an optical back-end system to an electronic computer. In this way we can take advantage of the speed and parallelism of digital optical processing. Using the proposed configuration we show how one might implement a set of text processing operations using lasers, spatial light modulators and photodetectors
.
File organizations and access methods for CLV disks
Authors: Christodoulakis S. , Ford D. A.
Published: January 2007

A large and important class of optical disc technology are CLV format discs such as CD ROM and WORM. In this paper, we examine the issues related to the implementation and performance of several different file organizations on CLV format optical discs such as CD ROM and WORM. The organizations examined are based on hashing and trees.

The CLV recording scheme is shown to be a good environment for efficiently implementing hashing. Single seek access and storage utilization levels approaching 100% can be achieved for CD ROM's. It is shown that a B-tree organization is not a good choice for WORM discs (both CAV and CLV), but a modified ISAM approach can be appropriate for WORM discs. We describe clustered BIM's, a class of tree organizations appropriate for CD ROMS. Expressions for the expected retrieval performance of both hashing and trees are also given.

The paper concludes by outlining recent results and future directions on buffered implementations of access methods for WORM discs, as well as advantages of signature based access methods for text retrieval in WORM disc architectures.
Full text indexing based on lexical relations an application: software libraries
Authors: Maarek Y. S. , Smadja F. Z.
Published: January 2007

In contrast to other kinds of libraries, software libraries need to be conceptually organized. When looking for a component, the main concern of users is the functionality of the desired component; implementation details are secondary. Software reuse would be enhanced with conceptually organized large libraries of software components. In this paper, we present GURU, a tool that allows automatical building of such large software libraries from documented software components. We focus here on GURU's indexing component which extracts conceptual attributes from natural language documentation. This indexing method is based on words' co-occurrences. It first uses EXTRACT, a co-occurrence knowledge compiler for extracting potential attributes from textual documents. Conceptually relevant collocations are then selected according to their resolving power, which scales down the noise due to context words. This fully automated indexing tool thus goes further than keyword-based tools in the understanding of a document without the brittleness of knowledge based tools. The indexing component of GURU is fully implemented, and some results are given in the paper.
Information retrieval using a hypertext-based help system
Authors: Campagnoni F. R. , Erlich K.
Published: January 2007

Hypertext offers users a simple, flexible way to navigate through electronic information systems but at the potential risk of becoming lost in the network of interconnected pieces of information. A study was conducted on information retrieval using a commercial hypertext based help system. It was found that the predominant search strategy was “browsing” (characterized by scanning tables of contents and paging through topics), rather than employing the indexes (“analytical search”). Although subjects did not become lost, individuals with better spatial visualization ability, as measured by a standardized test, were faster at retrieving information and returned to the top of the information hierarchy less often than those with poorer spatial visualization ability. These results support previous studies that have found a strong preference by users to browse in hypertext systems and extend those findings to a new domain (help), a different type of user interface, and a different information architecture. In addition, the results demonstrate the importance of spatial visualization ability for efficient navigation and information retrieval in a hierarchical hypertext system.
A hypertext knowledge based for primary care - LIMEDS in LINCKS
Authors: Timpka T. , Padgham L. , Hedblom P. , Wallin S. , Tibblin T.
Published: January 2007

In organized health care, primary care is the first level. It is characterized by the wide span of health problems managed as well as remote location from traditional medical information and knowledge sources. The LIMEDS project has formulated the special requirements for integrated knowledge and data base management in primary care. This paper presents
Gösta's book
, a hypertext knowledge base implemented in LINCKS, an object oriented, networked database system. Firstly, aspects which make integrated hypermedia systems particularly suitable for application in primary health care are explored. We then describe the hypertext knowledge base, consisting of 500 basic text objects and 3000 links, and current implementations using the NODE data model. NODE is implemented on a SUN III fileserver, and the user interface for the hypertext context on Apple Macintosh (TM). Combination of design methods towards a parallel means-ends strategy was found to be necessary to achieve
Gösta's book
. Design groups need to be composed of computer science, medical, psychological and organizational competences.
Information retrieval and software reuse
Authors: Frakes W. B.
Published: January 2007

Software reuse is widely believed to be the most promising technology for improving software quality and productivity. There are many technical and non-technical problems to be solved, however, before widespread reuse of software lifecycle objects becomes a reality. One class of problem concerns the classification, storage, and retrieval of reusable components. Panel members will discuss these problems and some approaches to solving them.
On the application of syntactic methodologies in automatic text analysis
Authors: Salton G. , Smith M.
Published: January 2007

This study summarizes various linguistic approaches proposed for document analysis in information retrieval environments. Included are standard syntactic methods to generate complex content identifiers, and the use of semantic know-how obtained from machine-readable dictionaries and from specially constructed knowledge bases. A particular syntactic analysis methodology is also outlined and its usefulness for the automatic construction of book indexes is examined.
The placement optimization program: a practical solution to the disk file assignment problem
Authors: Wolf J.
Published: January 2007

In this paper we describe a practical mathematical formulation and solution of the so-called “File Assignment Problem” (FAP) for computer disks. Our FAP solution has been implemented in a PL/I program known as the Placement Optimization Program (POP). The algorithm consists of three major components — two heuristic optimization models and a queueing network model. POP has been used in validation studies to assign files to disks in two IBM MVS complexes. The resulting savings in I/O response times were 22% and 25%, respectively. Throughout the paper we shall emphasize the real-world nature of our approach to the disk FAP, which we believe sets it apart from previous attempts.
Diversity in database reference behavior
Authors: Kearns J. P. , DeFazio S.
Published: January 2007

Over the past fifteen years, empirical studies of the reference behavior of a number of database systems have produced seemingly contradictory results. The presence or absence of locality of reference and sequentiality have both been reported (or denied) in various papers. As such, the performance analyst or database implementor is left with little concrete guidance in the form of expected reference behavior of a database system under a realistic workload. We present empirical evidence that all of the previous results about database reference behavior are correct (or incorrect). That is,
if the database reference sequence is viewed on a per-transaction instance or per-database basis
, almost any reference behavior is discernible. Previous results which report the absolute absence or presence of a certain form of reference behavior were almost certainly derived from reference traces which were dominated by transactions or databases which exhibited a certain behavior. Our sample consists of roughly twenty-five million block references, from 350,000 transaction executions, directed at 175 operational on-line databases at two major corporations. As such, the sample is an order of magnitude more comprehensive than any other reported in the literature.

We also present evidence that reference behavior is predictable and exploitable when viewed on a per-transaction basis or per-database basis. The implications of this predictability for effective buffer management are discussed.
A statistical approach to diagnosing intermittent performance-problems using monotone relationships
Authors: Hellerstein J.
Published: January 2007

Managing a computer system requires that good performance (e.g., large throughputs, small response times) be maintained in order to meet business objectives. Rarely is performance consistently bad. More frequently, performance is good one day and bad the next. Diagnosing such intermittent performance-problems involves determining what distinguishes bad days from good days, such as larger paging rates. Once this is understood, an appropriate remedy can be found, such as buying more memory. This paper describes a statistical approach to diagnosing intermittent performance-problems when the relationships among measurement variables are expressed qualitatively as monotone relationships (e.g., paging delays increase with the number of logged-on users). We present a non-parametric test for monotonicity (NTM) that evaluates monotone relationships based on

F
A

, the fraction of observation-pairs that agree with the monotone relationship. An interpretation of

F
A

in terms of statistical significance levels is presented, and NTM is compared to least-squares regression. Based on NTM, an algorithm for diagnosing intermittent performance-problems is presented. NTM and our diagnosis algorithm are applied to measurements of four similarly configured IBM 9370 model 60s running IBM's operating-system Virtual Machine System Product (VM SP).
Performance of optimistic make
Authors: Bubenik R. , Zwaenepoel W.
Published: January 2007

Optimistic make
is a version of
make
that executes the commands necessary to bring targets up-to-date
prior
to the time the user types a make request. Side effects of these
optimistic computations
(such as file or screen updates) are concealed until the make request is issued. If the inputs read by the optimistic computations are identical to the inputs the computation would read at the time the make request is issued, the results of the optimistic computations are used immediately, resulting in improved response time. Otherwise, the necessary computations are reexecuted.

We have implemented optimistic make in the V-System on a collection of SUN-3 workstations. Statistics collected from this implementation are used to synthesize a workload for a discrete-event simulation and to validate its results. The simulation shows a speedup distribution over pessimistic make with a median of 1.72 and a mean of 8.28. The speedup distribution is strongly dependent on the ratio between the target out-of-date times and the command execution times. In particular, with faster machines the median of the speedup distribution grows to 5.1, and then decreases again. The extra machine resources used by optimistic make are well within the limit of available resources, given the large idle times observed in many workstation environments.
Optimistic implementation of bulk data transfer protocols
Authors: Carter J. B. , Zwaenepoel W.
Published: January 2007

During a bulk data transfer over a high speed network, there is a high probability that the next packet received from the network by the destination host is the next packet in the transfer. An
optimistic
implementation of a bulk data transfer protocol takes advantage of this observation by instructing the network interface on the destination host to deposit the data of the next packet immediately into its anticipated final location. No copying of the data is required in the common case, and overhead is greatly reduced.

Our optimistic implementation of the V kernel bulk data transfer protocols on SUN-3/50 workstations connected by a 10 megabit Ethernet achieves peak
process-to-process
data rates of 8.3 megabits per second for 1-megabyte transfers, and 6.8 megabits per second for 8-kilobyte transfers, compared to 6.1 and 5.0 megabits per second for the pessimistic implementation. When the reception of a bulk data transfer is interrupted by the arrival of unexpected packets at the destination, the
worst-case
performance of the optimistic implementation is only 15 percent less than that of the pessimistic implementation. Measurements and simulation indicate that for a wide range of load conditions the optimistic implementation outperforms the pessimistic implementation.
Behavioral characterization of multiprocessor memory systems: a case study
Authors: Gallivan K. , Gannon D. , Jalby W. , Malony A. , Wijshoff H.
Published: January 2007

The speed and efficiency of the memory system is a key limiting factor in the performance of supercomputers. Consequently, one of the major concerns when developing a high-performance code, either manually or automatically, is determining and characterizing the influence of the memory system on performance in terms of algorithmic parameters. Unfortunately, the performance data available to an algorithm designer such as various benchmarks and, occasionally, manufacturer-supplied information, e.g. instruction timings and architecture component characteristics, are rarely sufficient for this task. In this paper, we discuss a systematic methodology for probing the performance characteristics of a memory system via a hierarchy of data-movement kernels. We present and analyze the results obtained by such a methodology on a cache-based multi-vector processor (Alliant FX/8). Finally, we indicate how these experimental results can be used for predicting the performance of simple Fortran codes by a combination of empirical observations, architectural models and analytical techniques.
Mache: no-loss trace compaction
Authors: Samples A. D.
Published: January 2007

Execution traces can be significantly compressed using their referencing locality. A simple observation leads to a technique capable of compressing execution traces by an order of magnitude; instruction-only traces are compressed by two orders of magnitude. This technique is unlike previously reported trace compression techniques in that it compresses without loss of information and, therefore, does not affect trace-driven simulation time or accuracy.
Solution of closed, product form, queueing networks via the RECAL and tree-RECAL methods on a shared memory multiprocessor
Authors: Greenberg A. G. , McKenna J.
Published: January 2007

RECAL is a new recurrence relation for calculating the partition function and various queue length moments for closed, product form networks. In this paper we discuss a number of the issues involved in the software implementation of RECAL on both sequential computers and parallel, shared memory computers. After a brief description of RECAL, we describe software implementing RECAL on a sequential computer. In particular, we discuss the problems involved in indexing and data storage. Next we describe code implementing RECAL on a parallel, shared memory computer. Special attention is given to designing a special buffer for temporary data storage and several other important features of the parallel code. Finally, we touch on software for serial and parallel implementations of a tree algorithm for RECAL.
Feedback queues with preemption-distance priorities
Authors: Paterok M. , Fischer O. , Opta L.
Published: January 2007

The method of moments is used to derive exact analytical solutions for an open priority queueing system with preemption-distance priorities and feedback. Customers enter from outside in a Poisson stream. They can feed back for several times, changing priorities and service demands in an arbitrary manner. During feedback they can fork and branch according to user-defined probabilities. The service demands of the different classes are pairwise independent and can be arbitrarily distributed. A customer who has been interrupted resumes his service from the point where he was interrupted (preemptive resume). A system of linear equations is to be solved to obtain the mean sojourn times of each customer class in the system.
Accurate modeling of parallel scientific computations
Authors: Nicol D. M. , Townsend J. C.
Published: January 2007

Scientific codes are usually parallelized by partitioning a grid among processors. To achieve top performance it is necessary to partition the grid so as to balance workload and minimize communication/synchronization costs. This problem is particularly acute when the grid is irregular, changes over the course of the computation, and is not known until load-time. Critical mapping and remapping decisions rest on our ability to accurately predict performance, given a description of a grid and its partition. This paper discusses one approach to this problem, and illustrates its use on a one-dimensional fluids code. The models we construct are shown empirically to be accurate, and are used to find optimal remapping schedules.
Approximating response time distributions
Authors: Raatikainen K. E. E.
Published: January 2007

The response time is the most visible performance index to users of computer systems. End-users see individual response times, not the average. Therefore the distribution of response times is important in performance evaluation and capacity planning studies. However, the analytic results cannot be obtained in practical cases. A new method is proposed to approximate the response-time distribution. Unlike the previous methods the proposed one takes into account the service-time distributions and routing behaviour. The reported results indicate that the method provides reasonable approximations in many cases.
A microprogrammed interpreter for concurrent euclid
Authors: Lall K. , Atwood J. W.
Published: January 2007

There are several methods of executing programs written in a high level language. The most widely used is to compile the programs into machine language. Another is to translate the programs into some intermediate form and then to execute that form interpretively. A third method is to directly execute either the HLL or the intermediate form.

This study was aimed at investigating the feasibility of directly executing the intermediate representation of the sequential features of Concurrent Euclid (CE) on the SEL 32/75 computer. The CE intermediate code was translated into Ecode, and a microprogrammed interpreter for Ecode was designed and implemented on the SEL, and benchmarked against the compiler. For the CPU-bound prime number algorithm Sieve of Eratosthenes, the interpreter was measured to be about twice as slow as the compiler, due primarily to poor overlap within microinstructions. Ecode was then modified, and a new translator and interpreter designed and implemented. The same benchmark then yielded comparable results for both the interpreter and compiler. We project that further changes in Ecode design and hardware support would result in substantial Ecode efficiency gains.
Functional languages in microcode compilers
Authors: Allan S. J.
Published: January 2007

This paper discusses the advantages of using high-level languages in the development of microcode. It also describes reasons functional programming languages should be considered as the source language for microcode compilers. The emergence of parallel execution in microarchitectures dictates that parallelism must be extracted from the microcode programs. This paper shows how functional languages meet the needs of microprogrammers by allowing them to express their algorithms in natural ways while allowing the microcode compiler to extract the parallelism from the program.
Design and performance measurements of a parallel machine for the unification algorithm
Authors: Sibai F. N. , Watson L. , Lu M.
Published: January 2007

Unification is known to be the most repeated operation in logic programming and PROLOG interpreters. To speed up the execution of logic programs, the performance of unification must be improved. We propose a parallel unification machine for speeding up the unification algorithm. The machine is simulated at the register transfer level and the simulation results as well as performance comparison with a serial unification coprocessor are presented.
A direct execution architecture for Prolog?
Authors: Brady M.
Published: January 2007

This paper describes work in progress on the development of a direct execution Prolog processor.
Design methodology and microdiagnostics development for a self-checking microprocessor
Authors: Parekhji R. A. , Nanda N. K.
Published: January 2007

The conventional design of electronic circuits is intolerant to operational faults. Self-checking logic is aimed at online fault detection and can hence be incorporated to achieve reliable operation. In this paper, the design of a self-checking microprocessor is discussed. Self-checking strategies for different functional units are selectively and judiciously applied, and also modified wherever necessary, for the design of the register section, the arithmetic & logic unit and the control unit. A self-checking microprogrammed control unit, capable of supporting normal instruction execution concurrently with diagnostics, is developed. The design methodology has been applied to Intel's 8085A microprocessor as a case study to make it self-testing. Overheads involved have also been estimated.
On optimal loop parallelization
Authors: Gasperoni F. , Schwiegelshohn U. , Ebcioğlu K.
Published: January 2007

The problem of automatic loop parallelization has received a lot of attention in the area of parallelizing compilers. Automatic loop parallelization can be achieved by several algorithms. In this paper we address the problem of time optimal parallelization of loops with conditional jumps. We prove that even for machines with unlimited resources there are simple loops for which no semantically and algorithmically equivalent time optimal program exists.
A VLSI based microprogramming evaluation system to support an instructional laboratory
Authors: Parker A. , Hamblen J. O.
Published: January 2007

A new low-cost VLSI based microprogrammable computer system is described. This system is an ideal candidate for use in student microprogramming laboratories. The authors describe their experiences in using this computer.
All example of using pseudofields to eliminate version shuffling in horizontal code compaction
Authors: Linn J. L. , Ardoin C. D.
Published: January 2007

This paper first reviews the version shuffling problem for microcode compaction. Next, a somewhat representative compaction problem involving asymmetric ALUs and a port-limited register file is presented. Finally, the paper shows how to model the architecture in a microcode compiler using the concept of
pseudofields
. While the modeling process is nontrivial, it is seen that this approach solves the version shuffling problem without introducing early-binding inefficiencies in the compiled code.
Forward semantic: a compiler-assisted instruction fetch method for heavily pipelined processors
Authors: Chang P.-H. , Hwu W.-M. W.
Published: January 2007

A new instruction fetch method,
forward semantic
, is offered to enable the deeply pipelined processors to fetch one useful instruction every cycle. Forward semantic is an improved alternative to the delayed branching (with or without squashing), with five major advantages. Fist, no restriction is imposed on the type of instructions filling the branch slots, which allows a large number of slots to be filled. Second, no modification to the offsets and displacements is necessary when an instruction is copied to fill a branch slot, which simplifies the linker implementation. Third, an interrupted program can resume execution with a single program counter, eliminating the need for reloading the instruction pipeline before resuming execution. Fourth, programs compiled with N slots can execute on pipelines requiring K (K ≤ N) slots, which makes family architecture compatibility possible . Lastly, the filling of branch slots is totally transparent to code compaction and software interlocking schemes. These advantages combine to provide an efficient instruction fetch mechanism and to eliminate artificial penalties on branch cost. At the cost of 11% static code expansion, forward semantic achieves an instruction fetch cost of 1.2 cycles for pipelines requiring 10 slots for each taken branch. This level of instruction fetch efficiency has never been achieved before with conventional instruction fetch methods. The branch cost is dictated by the accuracy of the compile-time branch prediction rather than artificial limitations, such as data dependencies, which prevent the slots from being filled. These results are measured from the execution of real UNIX and CAD programs with complex control structures.
A functional model of clocked microarchitectures
Authors: Charlton C. c. , Jackson D. , Leng P. H.
Published: January 2007

Models for the simulation of computer systems at the microarchitectural level are widely used to assist in design analysis and verification, and the development of microcode. The general model we describe here represents the behaviour of a clocked microarchitecture through the application of functions to component states and signal values. The operational semantics of the model are based partly on data flow and partly on graph reduction, allowing use to be made of the concept of 'lazy' evaluation to aid efficient simulation.
A flexible VLSI core for an adaptable architecture
Authors: Mulder H. , Stravers P.
Published: January 2007

Two major limitations concerning the design of cost-effective application-specific architectures are the recurrent costs of system-software development and hardware implementation, in particular VLSI implementation, for each architecture.

The SCalable ARChitecture Experiment (SCARCE) aims to provide a framework for application-specific processor design. The framework allows scaling of functionality, implementation complexity, and performance. The SCARCE framework consists and will consist of: an architecture framework defining the constraints for the design of application-specific architectures; tools for synthesizing architectures from application or application-area; VLSI cell libraries and tools for quick generation of application-specific processors; a system-software platform which can be retargeted quickly to fit the application-specific architecture;

This paper concentrates on the micro-architecture framework of SCARCE and outlines the process of generating VLSI processors.
Cryptographic techniques for privacy-preserving data mining
Authors: Pinkas Benny
Published: January 2007

Research in secure distributed computation, which was done as part of a larger body of research in the theory of cryptography, has achieved remarkable results. It was shown that non-trusting parties can jointly compute functions of their different inputs while ensuring that no party learns anything but the defined output of the function. These results were shown using generic constructions that can be applied to any function that has an efficient representation as a circuit. We describe these results, discuss their efficiency, and demonstrate their relevance to privacy preserving computation of data mining algorithms. We also show examples of secure computation of data mining algorithms that use these generic constructions.
Background and overview for KDD Cup 2002 task 1
Authors: Yeh Alexander , Hirschman Lynette , Morgan Alexander
Published: January 2007

This paper presents a background and overview for task 1 (of 2 tasks) of the KDD Challenge Cup 2002, a competition held in conjunction with the ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD), July 23--26, 2002. Task 1 dealt with detecting which papers, in a set of fruitfly genetics papers (texts), contained experimental results about gene products (transcripts and proteins), and also within each paper, which genes had experimental results about their products mentioned.
Multi-relational data mining
Authors: Džeroski Sašo , De Raedt Luc
Published: January 2007

In this report, we briefly review the Multi-Relational Data Mining workshop, which was held in Edmonton, Canada on July, 23, 2002 as part of the workshop program of the 8th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining (KDD-02).
A taxonomy of web search
Authors: Broder Andrei
Published: January 2007

Classic IR (information retrieval) is inherently predicated on users searching for information, the so-called "information need". But the need behind a web search is often not informational -- it might be navigational (give me the url of the site I want to reach) or transactional (show me sites where I can perform a certain transaction, e.g. shop, download a file, or find a map). We explore this taxonomy of web searches and discuss how global search engines evolved to deal with web-specific needs.
Challenges in web search engines
Authors: Henzinger Monika R. , Motwani Rajeev , Silverstein Craig
Published: January 2007

This article presents a high-level discussion of some problems in information retrieval that are unique to web search engines. The goal is to raise awareness and stimulate research in these areas.