ppxscal/embedding_network huggingface dataset:
Concurrent and Distributed Garbage Collection of Active Objects
Authors: Dennis Kafura, Manibrata Mukherji, Douglas M. Washabaugh
Venue: IEEE Transactions on Parallel and Distributed Systems (1995)

This paper shows how to perform concurrent and distributed automatic garbage collection of objects possessing their own thread of control. The relevance of garbage collection and active objects to distributed applications is briefly discussed and the specific model of active objects used in the paper is explained. The collector is comprised of independent local collectors, one per node, and a distributed global collector. The mutator (application), the local collectors and the global collector run concurrently. An important part of this paper is the detailed presentation of the algorithms necessary to achieve correct concurrent operation among the collectors and between the collectors and the mutator. The collector builds on previous algorithms for taking snapshots in distributed systems and for detecting termination.
A Teradata content-based multimedia object manager for massively parallel architectures
Authors: W. O'Connell, I. T. Ieong, D. Schrader, C. Watson, G. Au, A. Biliris, S. Choo, P. Colin, G. Linderman, E. Panagos, J. Wang, T. Walter
Venue: ACM SIGMOD Record (1996)

The Teradata Multimedia Object Manager is a general-purpose content analysis multimedia server designed for symmetric multiprocessing and massively parallel processing environments. The Multimedia Object Manager defines and manipulates user-defined functions (UDFs), which are invoked in parallel to analyze or manipulate the contents of multimedia objects. Several computationally intensive applications of this technology, which use large persistent datasets, include fingerprint matching, signature verification, face recognition, and speech recognition/translation.
Computing consequences: a framework for teaching ethical computing
Authors: Chuck Huff, C. Dianne Martin
Venue: Communications of the ACM (1995)

How to prepare tomorrow's professionals for questions that can't always be answered with faster, better, or more technology.
Intellectual archeology
Authors: Pat Hayes, Ken Ford
Venue: ACM SIGART Bulletin (1995)

We urge that an introductory course in AI should present a firm enough intellectual foundation to enable students to counter the many arguments being made against the subject's validity or coherence. Such foundations are not found in the history of the subject, on which many current texts spend too much time.
A control-theoretic approach to flow control
Authors: S. Keshav
Venue: ACM SIGCOMM Computer Communication Review (1995)

This paper presents a control-theoretic approach to reactive flow control in networks that do not reserve bandwidth. We assume a round-robin-like queue service discipline in the output queues of the network's switches, and propose deterministic and stochastic models for a single conversation in a network of such switches. These models motivate the Packet-Pair rate probing technique, and a provably stable rate-based flow control scheme. A Kalman state estimator is derived from discrete-time state space analysis, but there are difficulties in using the estimator in practice. These difficulties are overcome by a novel estimation scheme based on fuzzy logic. We then present a technique to extract and use additional information from the system to develop a continuous-time system model. This is used to design a variant of the control law that is also provably stable, and, in addition, takes control action as rapidly as possible. Finally, practical issues such as correcting parameter drift and coordination with window flow control are described.
Supporting the process of satisfying information needs with reusable software libraries: an empirical study
Authors: Scott Henninger
Venue: ACM SIGSOFT Software Engineering Notes (1995)

Retrieval tools for component-based software reuse libraries face two interrelated problems. The first is the ill-defined nature of information needs. The second is that large repositories will often use unfamiliar and esoteric vocabulary to describe software components. CodeFinder, a retrieval system designed to help developers locate software components for reuse, addresses these issues through an innovative combination of retrieval by reformulation and spreading activation. An empirical study comparing CodeFinder with two other systems showed evidence that subjects using CodeFinder with ill-defined tasks or mismatching vocabulary performed better than subjects using the other systems. The study confirmed the utility of spreading activation and retrieval by reformulation techniques for satisfying information needs of the kind encountered in software design.
The performance of an object-oriented, parallel operating system
Authors: David R. Kohr,  Jr., Xingbin Zhang, Mustafizur Rahman, Daniel A. Reed
Venue: Scientific Programming (1994)

The nascent and rapidly evolving state of parallel systems often leaves parallel application developers at the mercy of inefficient, inflexible operating system software. Given the relatively primitive state of parallel systems software, maximizing the performance of parallel applications not only requires judicious tuning of the application software, but occasionally, the replacement of specific system software modules with others that can more readily respond to the imposed pattern of resource demands. To assess the feasibility of application and performance tuning via malleable system software and to understand the performance penalties for detailed operating system performance data capture, we describe a set of performance instrumentation techniques for parallel, object-oriented operating systems and a set of performance experiments with Choices, an experimental, object-oriented operating system designed for use with parallel sys- tems. These performance experiments show that (a) the performance overhead for operating system data capture is modest, (b) the penalty for malleable, object-oriented operating systems is negligible, but (c) techniques are needed to strictly enforce adherence of implementation to design if operating system modules are to be replaced.
Static and dynamic partitioning of pointers as links and threads
Authors: David S. Wise, Joshua Walgenbach
Venue: Proceedings of the first ACM SIGPLAN international conference on Functional programming (1996)

Identifying some pointers as invisible threads, for the purposes of storage management, is a generalization from several widely used programming conventions, like threaded trees. The necessary invariant is that nodes that are accessible (without threads) emit threads only to other accessible nodes. Dynamic tagging or static typing of threads ameliorates storage recycling both in functional and imperative languages.We have seen the distinction between threads and links sharpen both hardware- and software-supported storage management in SCHEME, and also in C. Certainly, therefore, implementations of languages that already have abstract management and concrete typing, should detect and use this as a new static type.
The Minimization of Semicontinuous Functions: Mollifier Subgradients
Authors: Yuri M. Ermoliev, Vladimir I. Norkin, Roger J-B. Wets
Venue: SIAM Journal on Control and Optimization (1995)

To minimize discontinuous functions that arise in the context of systems with jumps, for example, we propose a new approach based on approximation via averaged functions (obtained by convolution with mollifiers). The properties of averaged functions are studied, after it is shown that they can be used in an approximation scheme consistent with minimization. A new notion of subgradient is introduced based on approximations generated by mollifiers and is exploited in the design of minimization procedures.
Sequential and Simultaneous Liftings of Minimal Cover Inequalitiesfor Generalized Upper Bound Constrained Knapsack Polytopes
Authors: Hanif D. Sherali, Youngho Lee
Venue: SIAM Journal on Discrete Mathematics (1995)

A family of facets for the GUB (Generalized Upper Bound) constrained knapsack polytope that are obtainable through a lifting procedure is characterized. The sequential lifting procedure developed herein computes lifted coefficients of the variables in each GUB set simultaneously, in contrast with the usual sequential lifting procedure that lifts only one variable at a time. Moreover, this sequential lifting procedure can be implemented in polynomial time of complexity $O(nm),$ where $n$ is the number of variables and $m(\leq n)$ is the number of GUB sets. In addition, a characterization of the facets obtainable through a simultaneous lifting procedure is derived. This characterization enables us to deduce lower and upper bounds on the lifted coefficients. In particular, for the case of the ordinary knapsack polytope, a known lower bound on the coefficients of lifted facets derived from minimal covers was further tightened.
Fractal views: a fractal-based method for controlling information display
Authors: Hideki Koike
Venue: ACM Transactions on Information Systems (TOIS) (1995)

Computer users often must view large amounts of information through video displays which are physically limited in size. Although some methods, which automatically display/erase information units based on their degrees of importance, have been proposed, they lack an ability to keep the total amount of displayed information nearly constant. We propose a new method for information display based on fractal theory. By regarding the information structures used in computers as complex objects, we can abstract these objects as well as control their amount. Using our method, (1) the total amount of information is kept nearly constant even when users change their focuses of attention and (2) this amount can be set flexibly. Through mathematical analysis, we show our method's ability to control the amount. An application to program display is also shown. When this method is applied to the display of structured programs, it provides fisheye-like views which integrate local details around the focal point and major landmarks further away.
HalClon: designing for people
Authors: Daniel Crow
Venue: ACM SIGCHI Bulletin (1995)

This short paper discusses some early work on the HalCIon project. The objective of this project is to develop an educational hypermedia CD-ROM teaching principles and practices of Human-Computer Interaction to a commercial audience.
Multicolor reordering of sparse matrices resulting from irregular grids
Authors: Rami G. Melhem, K. V. S. Ramarao
Venue: ACM Transactions on Mathematical Software (TOMS) (1988)

Many iterative algorithms for the solution of large linear systems may be effectively vectorized if the diagonal of the matrix is surrounded by a large band of zeroes, whose width is called the zero stretch. In this paper, a multicolor numbering technique is suggested for maximizing the zero stretch of irregularly sparse matrices. The technique, which is a generalization of a known multicoloring algorithm for regularly sparse matrices, executes in linear time, and produces a zero stretch approximately equal to n/2&sgr;, where 2&sgr; is the number of colors used in the algorithm. For triangular meshes, it is shown that &sgr; &le; 3, and that it is possible to obtain &sgr; = 2 by applying a simple backtracking scheme.
Applying cryptographic techniques to problems in media space security
Authors: Ian E. Smith, Scott E. Hudson, Elizabeth D. Mynatt, John R. Selbie
Venue: Proceedings of conference on Organizational computing systems (1995)

Media spaces integrate audio, video, and computing systems for the purpose of remote collaboration and awareness, frequently between people engaged in a cooperative task. Technological advances have made these systems feasible using desktop computers and broadband, digital networks. Using a media space over a shared network requires that numerous security and privacy issues be addressed. One advantage of digital media spaces is that properties of the media space can be manipulated so that users feel more comfortable with the technology. This paper details cryptographic techniques which can be used to create a secure and usable media space. This paper also explains the properties of a user interface which would enable users to ensure their level of privacy. This work also details two interface designs which provide users with sophisticated, flexible control of their media space without requiring a detailed understanding of the underlying cryptographic mechanisms.
The Normalized String Editing Problem Revisited
Authors: B. J. Oommen, K. Zhang
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1996)

Marzal and Vidal [8] recently considered the problem of computing the normalized edit distance between two strings, and reported experimental results which demonstrated the use of the measure to recognize hand-written characters. Their paper formulated the theoretical properties of the measure and developed two algorithms to compute it. In this short communication we shall demonstrate how this measure is related to an auxiliary measure already defined in the literature¿the inter-string constrained edit distance[10], [11], [15]. Since the normalized edit distance can be computed efficiently using the latter, the analytic and experimental results reported in [8] can be obtained just as accurately, but more efficiently, using the strategies presented here.
An information-maximization approach to blind separation and blind deconvolution
Authors: Anthony J. Bell, Terrence J. Sejnowski
Venue: Neural Computation (1995)

We derive a new self-organizing learning algorithm that maximizes the information transferred in a network of nonlinear units. The algorithm does not assume any knowledge of the input distributions, and is defined here for the zero-noise limit. Under these conditions, information maximization has extra properties not found in the linear case (Linsker 1989). The nonlinearities in the transfer function are able to pick up higher-order moments of the input distributions and perform something akin to true redundancy reduction between units in the output representation. This enables the network to separate statistically independent components in the inputs: a higher-order generalization of principal components analysis. We apply the network to the source separation (or cocktail party) problem, successfully separating unknown mixtures of up to 10 speakers. We also show that a variant on the network architecture is able to perform blind deconvolution (cancellation of unknown echoes and reverberation in a speech signal). Finally, we derive dependencies of information transfer on time delays. We suggest that information maximization provides a unifying framework for problems in "blind" signal processing.
Flattening and parallelizing irregular, recurrent loop nests
Authors: Anwar M. Ghuloum, Allan L. Fisher
Venue: ACM SIGPLAN Notices (1995)

Irregular loop nests in which the loop bounds are determined dynamically by indexed arrays are difficult to compile into expressive parallel constructs, such as segmented scans and reductions. In this paper, we describe a suite of transformations to automatically parallelize such irregular loop nests, even in the presence of recurrences. We describe a simple, general loop flattening transformation, along with new optimizations which make it a viable compiler transformation. A robust recurrence parallelization technique is coupled to the loop flattening transformation, allowing parallelization of segmented reductions, scans, and combining-sends over arbitrary associative operators. We discuss the implementation and performance results of the transformations in a parallelizing Fortran 77 compiler for the Cray C90 supercomputer. In particular, we focus on important sparse matrix-vector multiplication kernels, for one of which we are able to automatically derive an algorithm used by one of the fastest library routines available.
Modification of the minimum-degree algorithm by multiple elimination
Authors: Joseph W. H. Liu
Venue: ACM Transactions on Mathematical Software (TOMS) (1985)

The most widely used ordering scheme to reduce fills and operations in sparse matrix computation is the minimum-degree algorithm. The notion of multiple elimination is introduced here as a modification to the conventional scheme. The motivation is discussed using the k-by-k grid model problem. Experimental results indicate that the modified version retains the fill-reducing property of (and is often better than) the original ordering algorithm and yet requires less computer time. The reduction in ordering time is problem dependent, and for some problems the modified algorithm can run a few times faster than existing implementations of the minimum-degree algorithm. The use of external degree in the algorithm is also introduced.
Women in computing
Authors: Amy Pearl
Venue: Communications of the ACM (1995)

The world is changing and the demographics of the workforce are changing with it. At one time there was hope that our exciting new field of computer science would not only revolutionize the technical world in which we live, but break new ground in professional access and equity for women. This optimism has given way to pragmatism. If we want the best and the brightest women to participate fully in our profession, we must take a long hard look at our professional practices and conventions. The goal of this special section is to provide computer professionals with the information to understand the issues that women confront in their workplace and with the resources to successfully diversify their workplace. I hope you will save this issue of Communications as a reference for many years to come. I also hope that, as opportunities for women in computer science expand, the need for the specialized resources and programs we described here diminishes.
Simulation-based real-time decision making for route planning
Authors: Jin Joo Lee, Paul A. Fishwick
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Decision making is an active area of research in simulation, systems engineering and artificial intelligence. One subset area of decision making, automated route planning, is covered with our approach being based on the technique of simulation rather than on purely heuristic or geometric techniques. This new technique is called simulation-based planning. Simulation-based planning is useful for route planning under various conditions including uncertain locations and events with potential adversarial activity. We claim that it is only by using simulation that one can make the most effective plan in uncertain and complex environments. An experimental design is outlined along with our plans for further development.
Strict Approximation of Matrices
Authors: K. Zietak
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

This paper describes a mechanism that includes the well-known strict approximation of a real vector which can be applied in the case of spectral approximation to define a unique strict spectral approximant of a matrix. For this purpose a new ordering is introduced.
A Fast Approximation Algorithm for Computing theFrequencies of Subgraphs in a Given Graph
Authors: Richard A. Duke, Hanno Lefmann, Vojtech Rodl
Venue: SIAM Journal on Computing (1995)

In this paper we give an algorithm which, given a labeled graph on $n$ vertices and a list of all labeled graphs on $k$ vertices, provides for each graph $H$ of this list an approximation to the number of induced copies of $H$ in $G$ with total error small. This algorithm has running time $O(n^{{1 \over \log \log n}} \cdot M(n))$, where $M(n)$ is the time needed to square a $n$ by $n$ matrix with 0, 1-entries over the integers. The main tool in designing this algorithm is a variant of the regularity lemma of Szemeredi.
Evaluation and Selection of Biases in Machine Learning
Authors: Diana F. Gordon, Marie Desjardins
Venue: Machine Learning (1995)

In this introduction, we define the term bias as it is used in machine learning systems. We motivate the importance of automated methods for evaluating and selecting biases using a framework of bias selection as search in bias and meta-bias spaces. Recent research in the field of machine learning bias is summarized.
A versatile data structure for edge-oriented graph algorithms
Authors: Jürgen Ebert
Venue: Communications of the ACM (1987)

An abstract graph module that allows for easy and secure programming of a great number of graph algorithms is implemented by symmetrically stored forward and backward adjacency lists, thus supporting edge-oriented traversals of general directed and undirected graphs.
Panic! Unix system crash dump analysis
Authors: Chris Drake, Kimberley Brown
Venue:  (1995)

Designed as an introduction to UNIX system crash dump analysis, this is the first book to discuss in detail UNIX system panics, crashes and hangs, their causes, what to do when they occur, how to collect information about them, how to analyze that information, and how to get the problem resolved. KEY TOPICS: Part One covers theory and tools. Part Two looks inside UNIX, from the header files to hardware tape drives. Part Three provides actual case studies of software, hardware, data, and system fault problems. MARKET: For systems and network administrators and technical support engineers responsible for maintaining UNIX computer systems and networks.