ppxscal/embedding_network huggingface dataset:
A study examining the performance of the cyberlink mental interface
Authors: Eamon Doherty, Gilbert Cockton, Chris Bloor, Dennis Benigno
Venue: ACM SIGBIO Newsletter (2000)

A group of persons with a variety of neurological and mental impairments participated in a study to investigate the use of a mental interface and a trackball to point and click in a Windows 95 environment. Each participant's disability, medications, and performance with each input device are displayed. Some observations are made and discussed. The paper concludes with a participant using a newly modified version of the Yes No program to communicate. This person can use no other input device except using the Cyberlink to communicate or control a computer.
Detecting topical events in digital video
Authors: Tanveer Syeda-Mahmood, S. Srinivasan
Venue: Proceedings of the eighth ACM international conference on Multimedia (2000)

The detection of events is essential to high-level semantic querying of video databases. It is also a very challenging problem requiring the detection and integration of evidence for an event available in multiple information modalities, such as audio, video and language. This paper focuses on the detection of specific types of events, namely, topic of discussion events that occur in classroom/lecture environments. Specifically, we present a query-driven approach to the detection of topic of discussion events with foils used in a lecture as a way to convey a topic. In particular, we use the image content of foils to detect visual events in which the foil is displayed and captured in the video stream. The recognition of a foil in video frames exploits the color and spatial layout of regions on foils using a technique called region hashing. Next, we use the textual phrases listed on a foil as an indication of a topic, and detect topical audio events as places in the audio track where the best evidence for the topical phrases was heard. Finally, we use a probabilistic model of event likelihood to combine the results of visual and audio avent detection that exploits their time cooccurrence. The resulting identification of topical events is evaluated in the domain of classroom lectures and talks.
RELAX &mdash; the relational algebra pocket calculator project
Authors: Victor Matos, Rebecca Grasser
Venue: ACM SIGCSE Bulletin (2000)

Database courses benefit from the abundance of commercial SQL systems available today. Unfortunately, the same cannot be said about the relational algebra query language. This article considers a lab experience to integrate the learning of these two important topics. In the process of implementing the project, the student acquires practical knowledge in areas such as database programming, parsing and compiling, dynamic SQL code generation, object linking and embedding technologies (OLE), and problem solving skills using the framework of relational algebra. This activity is applied to a traditional second semester database theory course and appears to be very beneficial to the student.
Dynamic buffer allocation in video-on-demand systems
Authors: Sang-Ho Lee, Kyu-Young Whang, Yang-Sae Moon, Il-Yeol Song
Venue: Proceedings of the 2001 ACM SIGMOD international conference on Management of data (2001)

In video-on-demand (VOD) systems, as the size of the buffer allocated to user requests increases, initial latency and memory requirements increase. Hence, the buffer size must be minimized. The existing static buffer allocation scheme, however, determines the buffer size based on the assumption that the system is in the fully loaded state. Thus, when the system is in a partially loaded state, the scheme allocates a buffer larger than necessary to a user request. This paper proposes a dynamic buffer allocation scheme that allocates to user requests buffers of the minimum size in a partially loaded state as well as in the fully loaded state. The inherent difficulty in determining the buffer size in the dynamic buffer allocation scheme is that the size of the buffer currently being allocated is dependent on the number of and the sizes of the buffers to be allocated in the next service period. We solve this problem by the predict-and-enforce strategy, where we predict the number and the sizes of future buffers based on inertia assumptions and enforce these assumptions at runtime. Any violation of these assumptions is resolved by deferring service to the violating new user request until the assumptions are satisfied. Since the size of the current buffer is dependent on the sizes of the future buffers, the size is represented by a recurrence equation. We provide a solution to this equation, which can be computed at the system initialization time for runtime efficiency. We have performed extensive analysis and simulation. The results show that the dynamic buffer allocation scheme reduces initial latency (averaged over the number of user requests in service from one to the maximum capacity) to 1 &divide; 29.4 &nsim; 1 &divide; 11.0 of that for the static one and, by reducing the memory requirement, increases the number of concurrent user requests to 2.36 &sim; 3.25 times that of the static one when averaged over the amount of system memory available. These results demonstrate that the dynamic buffer allocation scheme significantly improves the performance and capacity of VOD systems.
A learning program which plays partnership dominoes
Authors: Michael H. Smith
Venue: Communications of the ACM (1973)

A learning program has been written in BASIC to play four-player partnership dominoes. Because dominoes is a game of incomplete information, the program uses somewhat different principles of artificial intelligence from those used in programs for games of complete information, such as checkers, chess, and go. The program was constructed to use a &ldquo;strategy signature table&rdquo; which classifies board situations through the interactions of game parameters. Each entry in the table contains adaptively determined weights indicating the advisability of various strategies. Once chosen, a strategy then employs probability analysis and linear polynomial evaluation to choose a move. Our program wins approximately two-thirds of its games in tournament situations, and has defeated championship players.
Data Security
Authors: Dorothy E. Denning, Peter J. Denning
Venue: ACM Computing Surveys (CSUR) (1979)

The rising abuse of computers and increasing threat to personal privacy through data banks have stimulated much interest in the technical safeguards for data. There are four kinds of safeguards, each related to but distinct from the others. Access controls regulate which users may enter the system and subsequently which data sets an active user may read or write. Flow controls regulate the dissemination of values among the data sets accessible to a user. Inference controls protect statistical databases by preventing questioners from deducing confidential information by posing carefully designed sequences of statistical queries and correlating the responses. Statistical data banks are much less secure than most people believe. Data encryption attempts to prevent unauthorized disclosure of confidential information in transit or in storage. This paper describes the general nature of controls of each type, the kinds of problems they can and cannot solve, and their inherent limitations and weaknesses. The paper is intended for a general audience with little background in the area.
A queuing model of a multiprogrammed computer with a two-level storage system
Authors: G. S. Shedler
Venue: Communications of the ACM (1973)

The results are presented of an analysis of a probabilistic model of a multiprogrammed computer system with a two-level storage system in which there is sequential dependency of accesses between the devices. Expressions are obtained for the long-run probability that both the CPU and each of the storage devices are busy. Some numerical results are given which quantify the gains in CPU utilization obtainable by multiprogramming in the presence of this type of storage system.
The power crust
Authors: Nina Amenta, Sunghee Choi, Ravi Krishna Kolluri
Venue: Proceedings of the sixth ACM symposium on Solid modeling and applications (2001)

The power crust is a construction which takes a sample of points from the surface of a three-dimensional object and produces a surface mesh and an approximate medial axis. The approach is to first approximate the medial axis transform (MAT) of the object. We then use an inverse transform to produce the surface representation from the MAT. This idea leads to a simple algorithm with theoretical guarantees comparable to those of other surface reconstruction and medial axis approximation algorithms. It also comes with a guarantee that does not depend in any way on the quality of the input point sample. Any input gives an output surface which is the `watertight' boundary of a three-dimensional polyhedral solid: the solid described by the approximate MAT. This unconditional guarantee makes the algorithm quite robust and eliminates the polygonalization, hole-filling or manifold extraction post-processing steps required in previous surface reconstruction algorithms. In this paper, we use the theory to develop a power crust implementation which is indeed robust for realistic and even difficult samples. We describe the careful design of a key subroutine which labels parts of the MAT as inside or outside of the object, easy in theory but non-trivial in practice. We find that we can handle areas in which the input sampling is scanty or noisy by simply discarding the unreliable parts of the MAT approximation. We demonstrate good empirical results on inputs including models with sharp corners, sparse and unevenly distributed point samples, holes, and noise, both natural and synthetic. We also demonstrate some simple extensions: intentionally leaving holes where there is no data, producing approximate offset surfaces, and simplifying the approximate MAT in a principled way to preserve stable features.
The Power of Tests for Non-Linearity: The Escribano&ndash;Pfann Model
Authors: Steven Cook, Sean Holly, Paul Turner
Venue: Computational Economics (2000)

The power of the recently proposed Escribano&ndash;Pfann (1998) model of asymmetry is examined via Monte Carlo simulation. As found previously for an alternative asymmetric model, the power of this model is seen to be low.
Some preliminary remarks on theoretical pragmatics
Authors: A. Caracciolo
Venue: Communications of the ACM (1966)

The term pragmatics has been used, as is well known, by Morris and Carnap to denote that branch of semiotics which deals with the relation between a language and its users. As such I don't like the term very much. But one might also define it to be that branch which deals with the relation between languages and actions or processes. This seems more appropriate to me. In any case, whatever the definition, there is a basic connection between programming languages and pragmatics, as pointed out by Gorn. I devoted a paragraph to this subject in my talk at the IFIP Congress 1965 entitled &ldquo;Linguistic Problems in Programming Theory.&rdquo; The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
Estimating and improving the quality of information in a MIS
Authors: Richard C. Morey
Venue: Communications of the ACM (1982)

Most discussions of MIS's assume that the information in the records is error-free although it is recognized that errors exist. These errors occur because of delays in processing times, lengthy correction times, and, overly or insufficiently stringent data edits. In order to enable the user to implement data edits and correction procedures tailored to the degree of accuracy needed, this paper presents functional relationships between three common measures of data quality. The MIS addressed is one where records in a MIS are updated as changes occur to the record, e.g., a manpower planning MIS where the changes may relate to a serviceman's rank or skills. Since each of the updating transactions may contain an error, the transactions are subjected to various screens before the stored records are changed. Some of the transactions including some that are correct, are rejected; these are reviewed manually and corrected as necessary. In the meantime, the record is out of date and in error. Some of the transactions that were not rejected also lead to errors. The result is that at any given time the MIS record may contain errors. For each of several error control mechanisms, we show how to forecast the level of improvement in the accuracy of the MIS record if these options are implemented.
A modification of Warshall's algorithm for the transitive closure of binary relations
Authors: Henry S. Warren,  Jr.
Venue: Communications of the ACM (1975)

An algorithm is given for computing the transitive closure of a binary relation that is represented by a Boolean matrix. The algorithm is similar to Warshall's although it executes faster for sparse matrices on most computers, particularly in a paging environment.
Collaborative augmented reality environments: integrating VR, working materials, and distributed work spaces
Authors: Monika Büscher, Michael Christensen, Kaj Grønbæk, Peter Krogh, Preben Mogensen, Dan Shapiro, Peter Ørbæk
Venue: Proceedings of the third international conference on Collaborative virtual environments (2000)

In this work, we present a new method for displaying stereo scenes, which speeds up the rendering time of complex geometry. We first discuss a scene splitting strategy, allowing us to partition objects to the distant background or the near foreground. Furthermore, wededuce a computation rule for positioning a cutting plane in the scene.
A constraint driven approach to loop pipelining and register binding
Authors: B. Mesman, M. Strik, A. H. Timmer, J. L. van Meerbergen, J. A. G. Jess
Venue: Proceedings of the conference on Design, automation and test in Europe (1998)

Code generation methods for DSP applications are hampered by the combination of tight timing constraints imposed by the performance requirements of DSP algorithms, and resource constraints imposed by a hardware architecture. In this paper, we present a method for register binding and instruction scheduling based on the exploitation and analysis of resource- and timing constraints. The analysis identifies sequencing constraints between operations additional to the precedence constraints. Without the explicit modeling of these sequencing constraints, a scheduler is often not capable of finding a solution that satisfies the timing, resource and register constraints. The presented approach results in an efficient method of obtaining high quality instruction schedules with low register requirements.
A decision procedure for term algebras with queues
Venue: ACM Transactions on Computational Logic (TOCL) (2001)

In software verification it is often required to prove statements about heterogeneous domains containing elements of various sorts, such as counters, stacks, lists, trees and queues. Any domain with counters, stacks, lists, and trees (but not queues) can be easily seen a special case of the term algebra, and hence a decision procedure for term algebras can be applied to decide the first-order theory of such a domain. We present a quantifier-elimination procedure for the first-order theory of term algebra extended with queues. The complete axiomatization and decidability of this theory can be immediately derived from the procedure.
Simulation and Measurement of Shot Noise in Resonant Tunneling Structures
Authors: G. Iannaccone, G. Lombardi, M. Macucci, C. Ciofi, B. Pellegrini
Venue: Analog Integrated Circuits and Signal Processing (2000)

We present numerical simulations and measurements of shot noise in resonant tunneling structures. We show that when electron-electron interaction through Coulomb force and Pauli exclusion is properly taken into account, the main features of noise behavior of such devices can be correctly predicted. Electron-electron interaction is shown to be responsible for the suppression of shot noise in the positive differential resistance region of the I-V curve, and for the enhancement of shot noise in the negative differential resistance region.
Employment characteristics of doctoral level computer scientists
Authors: Richard E. Fairley
Venue: Communications of the ACM (1979)

A recent report from the National Research Council contains a detailed profile of doctoral level scientists and engineers, as well as doctorates in the humanities [1]. This paper summarizes those portions of the report that pertain to the employment characteristics of Ph.D.'s in computer science, and other Ph.D. scientists and engineers working in computer science. Our purpose is to verify the common folklore concerning employment opportunities in computer science, academic vs. business/industry employment of doctoral level computer scientists, work activities at the doctoral level, and the relative numbers of Ph.D.'s working in the various subdisciplines of computer science.
A Linux-Based Automatic Backup System
Authors: Michael O'Brien
Venue: Linux Journal (2000)

A step-by-step procedure for establishing a backup system that will save time and money.
Landscapes of Practice: Bricolage as a Method for Situated Design
Authors: Monika Büscher, Satinder Gill, Preben Mogensen, Dan Shapiro
Venue: Computer Supported Cooperative Work (2001)

This paper proposes a `bricolage' approach to designing systems for cooperative work. This involves users, participatory designers and ethnographers in a continuing cycle of design and revised work practice, often in settings where resources are limited and short-term results are required. If exploits the flood to market of hardware, software and services. The approach is illustrated with results from a project with a practice of landscape architects. Their work is analysed in terms of communities of practice and actor networks. These perspectives help to identify the `socilities' of people and technologies and of the relationships between them. They help to distinguish different forms of cooperation with differing support needs, opportunities and vulnerabilities. They inform the design of technical support, the assessment of outcomes, and the design of further solutions, in a cycle of `situated experimentation'.
Some thoughts on reconciling various character set proposals
Authors: Edward A. Voorhees
Venue: Communications of the ACM (1960)

Recently there have appeared several proposals for expanded character sets. In general, these differ in the following respects: the number of characters in the expanded set, the characters selected, card and/or tape code representation, and superscripting and subscripting techniques. Currently, it seems to be popular to talk in terms of establishing a &ldquo;standard expanded character set.&rdquo; In the opinion of the author, this will prove to be extremely difficult in practice and undesirable in theory. This does not mean, however, that there should be no attempt to achieve &ldquo;minimal standard character subsets&rdquo; for communication purposes and &ldquo;universal languages.&rdquo;
Programming Languages: GPL, a truly general purpose language
Authors: Jan V. Garwick
Venue: Communications of the ACM (1968)

A truly general purpose programming language, GPL, is described which contains facilities for constructing (within the language) new data types as well as facilities for operations performed upon them. The basic language is minimal in the sense that no basic element can be derived from the others with high efficiency in the object programs. Constructs like the ALGOL 60 for-statements, and if-statements are not basic; they are special types of procedures. New &ldquo;symbols&rdquo; (underlined words in ALGOL 60) are implicitly defined by usage in other declarations. As part words are definable, packed words are handled as easily as full words. &ldquo;Address&rdquo; variables (pointers) are included in full generality.
Determining the minimum-area encasing rectangle for an arbitrary closed curve
Authors: H. Freeman, R. Shapira
Venue: Communications of the ACM (1975)

This paper describes a method for finding the rectangle of minimum area in which a given arbitrary plane curve can be contained. The method is of interest in certain packing and optimum layout problems. It consists of first determining the minimal-perimeter convex polygon that encloses the given curve and then selecting the rectangle of minimum area capable of containing this polygon. Three theorems are introduced to show that one side of the minimum-area rectangle must be collinear with an edge of the enclosed polygon and that the minimum-area encasing rectangle for the convex polygon is also the minimum-area rectangle for the curve.
Distributed Multimedia Application Configuration Management
Authors: Alexander Hagin, Gabriel Dermler, Kurt Rothermel, Gennadij Shchemelev
Venue: IEEE Transactions on Parallel and Distributed Systems (2000)

Employing distributed multimedia applications (DMA) requires management support for multiple configuration steps including the definition of a desired DMA topology, the specification of a desired quality of service (QoS) and its enforcement through resource reservation. In this paper, we examine the additional aspect of finding an appropriate placement for a DMA within a distributed computer system (DCS). An overall approach is described for interrelating placement functions with existing procedures for topology and QoS specification and resource reservation. Then the problem of assigning a DMA within a DCS is formulated with the goal of finding a DMA placement with minimized computation and communication cost. For solving the assignment problem an efficient heuristic algorithm¿SIGMA¿is presented. Unlike other approaches, SIGMA takes into account requirements, which are specific for multimedia applications. Based on experiments conducted for randomly generated DMA and DCS graphs, the efficiency and accuracy of SIGMA is shown to be encouraging because, at low execution times, it finds assignments with cost very close to the optimal one.
TOS: an educational distributed operating system in Java
Authors: Tyrone Nicholas, Jerzy A. Barchanski
Venue: ACM SIGCSE Bulletin (2001)

This paper describes TOS - an educational distributed operating system implemented in Java. First the current trends in commercial operating systems are shortly presented and compared with several available educational operating systems. Next we give our rationals to use Java as the TOS implementation language. Then the architecture of the system and its components - launchers and servers are described. Finally we explain the advantages of this architecture and give some examples of possible student projects and assignments.
On the meaning of names in programming systems
Authors: A. G. Fraser
Venue: Communications of the ACM (1971)

It is assumed that there is a similarity of function between the data names of a programming language and the file names of an operating system. The two functions are discussed in terms of the same basic concepts in order to identify the extent to which they overlap. It is suggested that there is some similarity between the idea of a file directory and a storable object of type context. Manipulations with contexts are then discussed at length. It is noted that there is a simple extension of Church's &lgr; notation that deals nicely with these ideas of context manipulation. Whereas a function can be regarded as the abstraction based upon the first two terms of the expression &lgr;(namelist)(expression)(valuelist), it is found that a context can be viewed as an abstraction based upon the first two terms in the equivalent expression &mgr;(namelist)(valuelist)(expression).