ppxscal/embedding_network huggingface dataset:
Understanding supercritical speedup
Authors: Michial A. Gunter
Venue: ACM SIGSIM Simulation Digest (1994)

Simulations running under Time Warp using lazy cancellation can beat the bound given by the critical path. We explain this phenomenon to be the result of a kind of intra-object parallelism. Specifically, we show that instances of beating the critical path, called supercritical speedup, are made possible by messages that are independent of some event which precedes the message. This insight leads to a new definition for the critical path which is a tighter lower bound on Time-Warp simulations using lazy cancellation than any previously proposed. These results suggest criteria for choosing between lazy and aggressive cancellation.
A model for belief revision in a multi-agent environment (abstract)
Authors: Aldo Franco Dragoni
Venue: ACM SIGOIS Bulletin (1992)

In modeling the knowledge processing structure of an Agent in a Multi-Agent world it becomes necessary to enlarge the traditional concept of Belief Revision. For detecting contradictions and identifying their sources it is sufficient to maintain informations about what has been told; but to "solve" a contradiction it is necessary to keep informations about who said it or, in general, about the source where that knowledge came from. We can take as certain the fact that an agent gave an information, but we can take the given information only as a revisable assumption. The Belief Revision system can't leave the sources of the informations out of consideration because of their relevance in giving the additional notion of "strength of belief" [Galliers 89]. In fact, the reliability of the source affects the credibility of the information and vice-versa. It is necessary to develop systems that deal with couples lt;assumption, source of the assumption gt; . In [Dragoni 91] we've proposed a system that moves in this direction. Here we give a short description of that system. In part one we describe the agent' s knowledge processing structure using a particular characterization of the "Assumption Based Belief Revision" concept; in part two we outline the project of an embedded device that enables the overall system to deal with couples lt;assumption, source of the assumption gt; in an rather anthropomorphic manner.
A componential model of human interaction with graphical display
Authors: Douglas J. Gillan
Venue: ACM SIGCHI Bulletin (1993)

A componential model of graphical interaction was developed based on analyses of humans interacting with graphical displays. The model, known as the Mixed Arithmetic--Perceptual (MA-P) model, proposes that five component processes underlie graphical interactions: Searching, Encoding, Arithmetic operations, Spatial comparison, and Responding. Experiment 1 demonstrated that the number of components for a given question--graph combination predicted the time to answer that question using that graph. Experiment 2 provided empirical support for two predictions from the model concerning the spatial relations among the elements of the graph. A metric for determining the ease of processing of a graph is outlined and guidelines for design of graphs are presented.
Stability of Recursive Stochastic Tracking Algorithms
Authors: Lei Guo
Venue: SIAM Journal on Control and Optimization (1994)

First, the paper gives a stability study for the random linear equation $X_{n+1}=(I-A_{n})x_n$. It is shown that for a quite general class of random matrices $\{A_n\}$ of interest, the stability of such a vector equation can be guaranteed by that of a corresponding scalar linear equation, for which various results are given without requiring stationary or mixing conditions. Then, these results are applied to the main topic of the paper, i.e., to the estimation of time varying parameters in linear stochastic systems, giving a unified stability condition for various tracking algorithms including the standard Kalman filter, least mean squares, and least squares with forgetting factor.
Comparing object-oriented analysis with knowledge acquisition
Authors: Hermann Kaindl
Venue: ACM SIGPLAN OOPS Messenger (1994)

Based on our experience and a theoretical comparison, we see an interesting relationship between object-oriented analysis in software engineering and certain aspects of knowledge acquisition in the course of building knowledge-based (expert) systems. In particular, we discuss here issues of modeling and the process dimension, i.e., how to do this modeling. According to this relationship, these fields should be able to stimulate each other.
Group Actions on the Cubic Tree
Authors: Marston Conder
Venue: Journal of Algebraic Combinatorics: An International Journal (1992)

It is known that every group which acts transitively on the ordered edges of the cubic tree &Gamma;3, with finite vertex stabilizer, is isomorphic to one of seven finitely presented subgroups of the full automorphism group of &Gamma;3&ndash;one of which is the modular group. In this paper a complete answer is given for the question (raised by Djokovi&cacute; and Miller) as to whether two such subgroups which intersect in the modular group generate their free product with the modular group amalgamated.
A comparison of object-oriented analysis and design methods (abstract)
Authors: Martin Fowler
Venue: Addendum to the proceedings on Object-oriented programming systems, languages, and applications (Addendum) (1992)

A Comparison of Object-Oriented Analysis and Design Methods Martin Fowler This tutorial shows how to look inside design and analysis methods to see how they differ, and more importantly, how they are the same. It examines several of the most well-known methods, including Booth, Coad/Yourdon, Odell/Martin, Rumbaugh, and Schlaer/Mellor, but its analysis techniques can be applied to any method. In general, each method is made up of several techniques (e.g. ER modeling, state transition diagrams) each of which emphasizes a particular aspect of the system. These techniques can be classified as being for structural (data), behavioral architectural modeling. The tutorial shows the techniques each method uses and how different methods use different dialects of the same I techniques, varying the notation and introducing new concepts. It uses examples to show how the same system is expressed in different ways by the various methods. The tutorial also compares the design approach advocated by each method. This tutorial will help you decide which method will work best for you. In addition, you will learn how ideas from different methods can be combined to better suit the system under analysis.
Techniques for automatically correcting words in text (abstract)
Authors: Karen Kukich
Venue: Proceedings of the 1993 ACM conference on Computer science (1993)

Research aimed at correcting words in text has focused on three progressively more difficult problems: 1) non-word error detection; 2) isolated-word error correction; and 3) context dependent word correction. In response to the first problem, efficient pattern matching and n-gram analysis techniques have been developed for detecting strings that do not appear in a given word list. In response to the second problem, a variety of general and application-specific spelling correction techniques have been developed. Some of them were based on detailed studies of spelling error patterns. In response to the third problem, a few experiments using natural language processing tools or statistical language models have been carried out. This article surveys documented findings on spelling error correction techniques, reviews the state of the art of context-dependent word correction techniques, and discusses research issues related to all three areas of automatic error correction in text. (The Article on which the Talk was based appeared in the December 1992 Issue of Computing Surveys)
Educational perspectives in collaborative hypermedia
Authors: Roy Rada, Phillip Ramsey, Antonios Michailidis
Venue: Proceedings of the 1993 ACM conference on Computer science (1993)

In education collaborative hypermedia complements the groupworking process and brings about innovations that make this process more effective. Collaborative hypermedia has been in use at the University of Liverpool for a number of years in the form of the MUCH (Many Using and Creating Hypermedia) system. This paper explores the appropriateness of collaborative hypermedia in teaching and peer assessment. Our experiences in using MUCH in teaching and peer assessment have revealed that students benefit from being responsible for their own learning and from assessing the work of their peers. The focus of the paper highlights how the new methodology fits into the work flow, the strategies and techniques that have been developed to adopt the new technology, and the potential of collaborative hypermedia to support teaching and peer assessment.
Human-machine perceptual cooperation
Authors: Francis K. H. Quek, Michael C. Petro
Venue: Proceedings of the INTERACT '93 and CHI '93 conference on Human factors in computing systems (1993)

The Human-Machine Perceptual Cooperation (HMPC) paradigm combines a human operator's high level reasoning with machine perception to solve spatio-perceptual intensive problems. HMPC defines two channels of interaction: the focus of attention (FOA) by which the user directs the attention of machine perception, and context. As the user moves the FOA across a display via a pointing device, a smart cursor operates proactively on the data, highlighting objects which satisfy the current contest. The FOA permits foveal emphasis, enabling the user to vary motor precision with image clutter. HMPC provides for contexts at four levels of abstraction. This permits the efficiency of the system to degrade gracefully as data quality worsens. We describe a document analysis application to which HMPC is applied. In this project, a human operator works with a machine to convert scanned raster maps into vector format.
N-folded Symmetries by Complex Moments in Gabor Space and their Application to Unsupervised Texture Segmentation
Authors: Josef Bigün, J. M. Hans du Buf
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1994)

Complex moments of the Gabor power spectrum yield estimates of the N-folded symmetry of the local image content at different frequency scales, that is, they allow to detect linear, rectangular, hexagonal/triangular, and so on, structures with very fine to very coarse resolutions. Results from experiments on the unsupervised segmentation of real textures indicate their importance for image processing applications. Real geometric moments computed in Gabor space also provide for very powerful texture features, but lack the clear geometrical interpretation of complex moments.
Uniform Exponential Stability and Approximation in Control of a Thermoelastic System
Authors: Zhuangyi Liu, Songmu Zheng
Venue: SIAM Journal on Control and Optimization (1994)

This paper has two objectives. First, necessary and sufficient conditions are given to characterize the uniform exponential stability of a sequence of $c_0$-semigroups $T_{n}(t)$ on Hilbert space $H_n$. Secondly, approximation in control of a one-dimensional thermoelastic system, subject to Dirichlet-Dirichlet as well as Dirichlet-Neumann boundary conditions, is considered. The uniform exponential stability and strong convergence of corresponding semigroups associated with approximate scheme are proved. Numerical experimental results are also presented.
Parallel destructive updating in strict functional languages
Authors: A. V. S. Sastry, William Clinger
Venue: Proceedings of the 1994 ACM conference on LISP and functional programming (1994)

In our recent paper, we gave an efficient interprocedural update analysis algorithm for strict functional languages with flat arrays and sequential evaluation. In this paper, we show that the same algorithm extends to a parallel functional language with additional constructs for partitioning and combining arrays. Even with parallel evaluation, the complexity of the analysis remains polynomial. The analysis has been implemented and the results show that several numerical algorithms such as direct and iterative methods for solving linear equations, LU, Cholesky, and QR factorizations, multigrid methods for solving partial differential equations, and non-numeric algorithms such as sorting can be implemented functionally with all updates made destructive. We describe a new array construct to specify a collection of updates on an array and show that problems like histogram, inverse permutation, and polynomial multiplication have efficient parallel functional solutions. Monolithic array operators can be considered as a special case of this new construct.
Tivoli: an electronic whiteboard for informal workgroup meetings
Authors: Elin Rønby Pedersen, Kim McCall, Thomas P. Moran, Frank G. Halasz
Venue: Proceedings of the INTERACT '93 and CHI '93 conference on Human factors in computing systems (1993)

This paper describes Tivoli, an electronic whiteboard application designed to support informal workgroup meetings and targeted to run on the Xerox Liveboard, a large screen, pen-based interactive display. Tivoli strives to provide its users with the simplicity, facile use, and easily understood functionality of conventional whiteboards, while at the same time taking advantage of the computational power of the Liveboard to support and augment its users' informal meeting practices. The paper presents the motivations for the design of Tivoli and briefly describes the current version in operation. It then reflects on several issues encountered in designing Tivoli, including the need to reconsider the basic assumptions behind the standard desktop GUI, the use of strokes as the fundamental object in the system, the generalized wipe interface technique, and the use of meta-strokes as gestural commands.
Data management for mobile computing
Authors: Tomasz Imieĺinski, B. R. Badrinath
Venue: ACM SIGMOD Record (1993)

Mobile Computing is a new emerging computing paradigm of the future. Data Management in this paradigm poses many challenging problems to the database community. In this paper we identify these new challenges and plan to investigate their technical significance. New research problems include management of location dependent data, wireless data broadcasting, disconnection management and energy efficient data access.
Advanced CLOS and meta-object protocols (abstract)
Authors: Jon L. White
Venue: Addendum to the proceedings on Object-oriented programming systems, languages, and applications (Addendum) (1992)

Advanced CLOS and Meta-Object Protocols Jon L. White, Lucid One of the important characteristics of CLOS is its dynamic flexibility to change descriptions, programs, and even data objects on the fly. A typical CLOS system is implemented by a set of meta-objects, which can be changed by the programmer, essentially letting you create a new language. Thus, CLOS is a reflective programming language. The main purpose of this tutorial is to teach you how to put a meta-object protocol to a practical use. In addition to describing the implementation of a typical CLOS system and discussing the various issues raised by the book Art of the Meta-Object Protocol, it gives practical examples of meta-object extensions including techniques for making user-defined metaclasses, for making alternations to SLOT-VALUE so that certain slots can be persistent, and for making metaclasses whose classes automatically keep a table of all their instances. The tutorial is aimed at the CLOS programmer or the programming language expert who would like to learn more about reflective programming using a meta-object protocol. The emphasis is on practical uses of a meta-object protocol, not on the philosophy of reflection.
Report on the CHI'91 workshop on languages for developing user interfaces
Authors: Brad A. Myers
Venue: ACM SIGCHI Bulletin (1993)

In his keynote address to the SIGCHI'90 conference, Michael Dertouzos said:When computers first appeared, input/output commands were a minor afterthought to cohesive, often well crafted and occasionally pretentious programming languages. Today, these commands occupy over 70 percent of a programming system's instructions. Yet they, along with the user interface structures that they define, are far from cohesive, and, at least up until now, immune to standardization. We must therefore turn our thinking around and create a new breed of programming languages that are first and foremost input/output oriented and that integrate traditional processing commands into new user-oriented structures. And just as we know today that traditional commands fall into a handful of fixed categories---decision, repetition, naming, procedure definition and use---we need to search for and identify the corresponding natural classes of commands for user interfaces. [Dertouzos 90]
The rhetoric of ethics compromised
Authors: Michael Davis
Venue: ACM SIGDOC Asterisk Journal of Computer Documentation (1994)

The title of Gregory Clark's article identifies it as a contribution to the field of technical communications ethics. Though I have written on business and professional ethics, including technical communications between engineers and managers, I know little about the ethics of technical communicators. My comments here are therefore necessarily those of an outsider, someone unaware of much that specialists in technical communications take for granted. I am bound to stumble. But perhaps I can also shed revealing light where I happen to fall. Because I believe criticism of Clark's article is likely to be more useful than praise, I shall keep the praise short (and leave it for last).
Agent language NUML and its reduction implementation model based on HO&pgr;
Authors: Xu Manwu, Lu Jianfeng, Zeng Fancong, Dai Jingwen
Venue: ACM SIGPLAN Notices (1994)

Higher--order pi;--calculus(HO pi;)[3.4.6]] is a computation model with sufficient computation capability. It is suitable to describe the concurrency in computation. In this paper, the agent language NUML which is designed to describe DAI (distributed artificial intelligence) systems is presented; also its semantics in HO pi; is given and finalliy a reduction implementation model of NUML based on HO pi; is submitted.
Information systems internships: the student perspective
Authors: Karen Ketler, John Walstrom
Venue: Proceedings of the 1993 conference on Computer personnel research (1993)

This article reports the results of a survey of 21 internships in information systems. Results showed that there was a wide variety of activities used in the internship. However, older technologies, such as COBOL, were mentioned more often than the newer technologies, such as CASE and SQL. The internships were rated based on the five core job characteristics as defined by Hackmana nd Oldham. As expected, skill variety was the lowest rated. Students indicated that they did NOT desire to learn a variety of new tools in the internship, but were contented to utilize what they already knew. The other four job characteristics, task identity, task significance, autonomy, and feedback were present in the internships. Additional results about the students' confidence and reasons for accepting the internship are also reported.
Usability foresight: strategic usability planning: a special interest group meeting report
Authors: Alan J. Happ
Venue: ACM SIGCHI Bulletin (1994)

This is the report of a Special Interest Group (SIG) meeting on Usability Foresight held at CHI'92. The discussion focused on how to set meaningful priorities for human factors/ usability research into human-computer interactions. This report describes the method presented and summarizes the results of a hands-on activity completed during the meeting.
Beyond uniformity and independence: analysis of R-trees using the concept of fractal dimension
Authors: Christos Faloutsos, Ibrahim Kamel
Venue: Proceedings of the thirteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1994)

We propose the concept of fractal dimension of a set of points, in order to quantify the deviation from the uniformity distribution. Using measurements on real data sets (road intersections of U.S. counties, star coordinates from NASA's Infrared-Ultraviolet Explorer etc.) we provide evidence that real data indeed are skewed, and, moreover, we show that they behave as mathematical fractals, with a measurable, non-integer fractal dimension.Armed with this tool, we then show its practical use in predicting the performance of spatial access methods, and specifically of the R-trees. We provide the first analysis of R-trees for skewed distributions of points: We develop a formula that estimates the number of disk accesses for range queries, given only the fractal dimension of the point set, and its count. Experiments on real data sets show that the formula is very accurate: the relative error is usually below 5%, and it rarely exceeds 10%.We believe that the fractal dimension will help replace the uniformity and independence assumptions, allowing more accurate analysis for any spatial access method, as well as better estimates for query optimization on multi-attribute queries.
The HCI bibliography project
Authors: Gary Perlman
Venue: ACM SIGCHI Bulletin (1993)

The HCI Bibliography is a free-access online bibliographic database on Human-Computer Interaction. The basic goal of the project is to put an electronic bibliography for most of HCI on the screens of all researchers, developers, educators and students in the field through anonymous ftp access, mail servers, and Macintosh and DOS floppy disks. Through the efforts of over 100 volunteers from 13 nations, the bibliography has grown to a resource of over 7500 entries occupying over 8 megabytes, used by over 300 sites in 23 nations. This notice describes the contents of the bibliography and how to access it.
Providing location information in a ubiquitous computing environment (panel session)
Authors: Mike Spreitzer, Marvin Theimer
Venue: ACM SIGOPS Operating Systems Review (1993)

To take full advantage of the promise of ubiquitous computing requires the use of location information, yet people should have control over who may know their whereabouts. We present an architecture that achieves these goals for an interesting set of applications. Personal information is managed by User Agents, and a partially decentralized Location Query Service is used to facilitate location-based operations. This architecture gives users primary control over their location information, at the cost of making more expensive certain queries, such as those wherein location and identity closely interact. We also discuss various extensions to our architecture that offer users additional trade-offs between privacy and efficiency. Finally, we report some measurements of the unextended system in operation, focusing on how well the system is actually able to track people. Our system uses two kinds of location information, which turn out to provide partial and complementary coverage.
Constraints among argument sizes in logic programs (extended abstract)
Authors: Kirack Sohn
Venue: Proceedings of the thirteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems (1994)

In logic programs the argument sizes of derivable facts w.r.t. an n-ary predicate are viewed as a set of points in Rn, which are approximated by their convex hull. Interargument constraint w.r.t. a predicate is essentially a set of constraints that every derivable fact of the predicate satisfies. We formalize such constraints by a fixpoint of recursive transformation similar to immediate consequence operator. However, the transformation does not necessarily converge finitely. Approximating polycones to their affine hulls provides useful interargument constraints in many practical programs, guaranteeing finite convergence. For a class of linear recursive logic programs satisfying translativeness property, precise interargument constraints can be obtained by an analysis of structures of recursive transformations.