ppxscal/embedding_network huggingface dataset:
Frame-sliced partitioned parallel signature files
Authors: Fabio Grandi, Paolo Tiberio, Pavel Zezula
Venue: Proceedings of the 15th annual international ACM SIGIR conference on Research and development in information retrieval (1992)

The retrieval capabilities of the signature file access method have become very attractive for many data processing applications dealing with both formatted and unformatted data. However, performance is still a problem, mainly when large files are used and fast response required. In this paper, a high performance signature file organization is proposed, integrating the latest developments both in storage structure and parallel computing architectures. It combines horizontal and vertical approaches to the signature file fragmentation. In this way, a new, mixed decomposition scheme, particularly suitable for parallel implementation, is achieved. The organization, based on this fragmentation scheme, is called Fragmented Signature File. Performance analysis shows that this organization provides very good and relatively stable performance, covering the full range of possible queries. For the same degree of parallelism, it outperforms any other parallel signature file organization that has been defined so far. The proposed method also has other important advantages concerning processing of dynamic files, adaptability to the number of available processors, load balancing, and, to some extent, fault-tolerant query processing.
How you can use the data encryption standard to encrypt your files and data bases
Authors: Roy F. Van Buren
Venue: ACM SIGSAC Review (1990)

Through this paper, I am going to show you how you can use data encryption to effectively secure your files and databases.
Broad agents
Authors: Joseph Bates, Bryan Loyall, W. Scott Reilly
Venue: ACM SIGART Bulletin (1991)

The Oz project at Carnegie Mellon is developing technology for dramatic virtual worlds. One requirement of such worlds is the presence of broad, though perhaps shallow, agents. To support our needs, we are developing an agent architecture that provides goals and goal directed reactive behavior, emotional state and its effects on behavior, some natural language abilities (especially pragmatics based language generation), and some memory and inference abilities. We are limiting each of these capacities whenever necessary to allow us to build a broadly capable, integrated agent.In attempting to construct a broad agent, constraints seem to arise between components of the architecture. In this brief note, we discuss some of these constraints.
Language learning from stochastic input
Authors: Syam Kapur, Gianfranco Bilardi
Venue: Proceedings of the fifth annual workshop on Computational learning theory (1992)

Language learning from positive data in the Gold model of inductive inference is investigated in a setting where the data can be modeled as a stochastic process. Specifically, the input strings are assumed to form a sequence of identically distributed, independent random variables, where the distribution depends on the language being presented. A scheme is developed which can be tuned to learn, with probability one, any family of recursive languages, given a recursive enumeration of total indices for the languages in the family and a procedure to compute a lower bound to the probability of occurrence of a given string in a given language. Variations of the scheme work under other assumptions, e.g., if the probabilities of the strings form a monotone sequence with respect to a given enumeration. The learning algorithm is rather simple and appears psychologically plausible. A more sophisticated version of the learner is also developed, based on a probabilistic version of the notion of tell-tale subset. This version yields, as a special case, Angluin's learner for the families of languages that are learnable from all texts (and not just from a set of texts of probability one).
Dynamics of congestion control and avoidance of two-way traffic in an OSI testbed
Authors: Rick Wilder, K. K. Ramakrishnan, Allison Mankin
Venue: ACM SIGCOMM Computer Communication Review (1991)

An extensive set of measurements were made in an OSI testbed to study the behavior of congestion control and avoidance. Testbed systems used the Connectionless Network Protocol (CLNP) and Transport Protocol Class 4 (TP4), which had been modified to perform the CE-bit [10] congestion avoidance and the "CUTE" [6] congestion recovery algorithms.We found that two-way traffic has dynamics which can significantly decrease fairness among competing connections using congestion avoidance. We present experiments that demonstrate this problem and our analysis of how two-way traffic results in reduced fairness. This analysis led us to develop an effective modification to the congestion avoidance algorithms to maintain fairness with two-way traffic.Our analysis of experimental results also points to undesirable interactions between two-way traffic dynamics and a sending strategy that times data transmissions, by the receipt of acknowledgements. These interactions reinforce burstiness of transmissions. therefore increasing buffering requirements and delay in routers. They may also decrease throughput.
Optimal VLSI Sorting with Reduced Number of Processors
Authors: Hussein M. Alnuweiri, V. K. Prasanna Kumar
Venue: IEEE Transactions on Computers (1991)

A new parallel architecture is presented which has p processors and N=n/sup 2/ memory locations, each consisting of 2s bits. The proposed organization can sort N s-bit numbers, where s=O((1+ epsilon ) log N), epsilon
The revised Fundamental Theorem of Moment Invariants
Authors: T. H. Reiss
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

A revised fundamental theorem of moment invariants for pattern recognition which corrects the fundamental theorem proposed by M.K. Hu (1962), is presented. The correction affects neither similitude (scale) nor rotation invariants derived using the original theorem, but it does affect features invariant to general linear transformations. Four of the latter invariants were presented originally by Hu. These are revised to take the correction to the fundamental theorem into account. Furthermore, these four invariants are combined to yield three new invariants, which are additionally invariant to changes in the illumination of an image.
The dynamic HomeFinder: evaluating dynamic queries in a real-estate information exploration system
Authors: Christopher Williamson, Ben Shneiderman
Venue: Proceedings of the 15th annual international ACM SIGIR conference on Research and development in information retrieval (1992)

We designed, implemented, and evaluated a new concept for visualizing and searching databases utilizing direct manipulation called dynamic queries. Dynamic queries allow users to formulate queries by adjusting graphical widgets, such as sliders, and see the results immediately. By providing a graphical visualization of the database and search results, users can find trends and exceptions easily. User testing was done with eighteen undergraduate students who performed significantly faster using a dynamic queries interface compared to both a natural language system and paper printouts. The interfaces were used to explore a real-estate database and find homes meeting specific search criteria.
APPGEN: a tool for teaching systems analysis and design
Authors: M. Osborne
Venue: Proceedings of the twenty-third SIGCSE technical symposium on Computer science education (1992)

APPGEN is a program which generates information systems. It is easy to use and powerful and runs on a VAX under VMS. It has been used with success in senior level courses on systems analysis and design. Using APPGEN, students are able to analyze and design systems of realistic size and still have time to implement them. Implementations give students important feedback about their designs and give additional focus to a class on systems analysis and design. Students get satisfaction from actually creating a working system.
On the Verification of Hypothesized Matches in Model-Based Recognition
Authors: W. Eric L. Grimson, Daniel P. Huttenlocher
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1991)

Model-based recognition methods generally use ad hoc techniques to decide whether or not a model of an object matches a given scene. The most common such technique is to set an empirically determined threshold on the fraction of model features that must be matched to data features. Conditions under which to accept a match as correct are rigorously derived. The analysis is based on modeling the recognition process as a statistical occupancy problem. This model makes the assumption that pairings of object and data features can be characterized as a random process with a uniform distribution. The authors present a number of examples illustrating that real image data are well approximated by such a random process. Using a statistical occupancy model, they derive an expression for the probability that a randomly occurring match will account for a given fraction of the features of a particular object. This expression is a function of the number of model features, the number of data features, and bounds on the degree of sensor noise. It provides a means of setting a threshold such that the probability of a random match is very small.
An advanced operating systems project using concurrency
Authors: Ronald J. Leach
Venue: ACM SIGCSE Bulletin (1990)

Most courses in operating systems follow one of three patterns: high level discussion with most programming done in a high level language; building operating systems from device driver level up; and courses which use emulator programs which emulate special architectures. In this paper, we describe a course which emphasizes the strong points of these approaches. The course also emphasizes teaching concurrency, introducing networking, and developing a deeper understanding of many of the system calls and system commands of the UNIX operating system. The major course project is described in the paper.
Guarded attribute grammars: top down parsing and left recursive productions
Authors: Richard A. Frost
Venue: ACM SIGPLAN Notices (1992)

It is widely believed that top down parsing is incompatible with left recursive grammars. We show that this is not true. We describe a novel device by which left recursive productions can be directly compiled into executable interpreters that use a top down parsing strategy. We show how our technique can be used to construct executable attribute grammars that are both modular and expressively natural. We have implemented the technique as an extension to an attribute grammar programming environment which has been tested on a number of projects including the development of theorem provers, natural language processors, and database query processors.
Synthetic Traces for Trace-Driven Simulation of Cache Memories
Authors: Joel L. Wolf, Harold S. Stone, Dominique Thiébaut
Venue: IEEE Transactions on Computers (1992)

Two techniques for producing synthetic address traces that produce good emulations of the locality of reference of real programs are presented. The first algorithm generates synthetic addresses by simulating a random walk in an infinite address-space with references governed by a hyperbolic probability law. The second algorithm is a refinement of the first in which the address space has a given finite size. The basic model for the random walk has two parameters that correspond to the working set size and the locality of reference. By comparing synthetic traces with real traces of identical locality parameters, it is demonstrated that synthetic traces exhibit miss ratios and lifetime functions that compare well with those of the real traces they mimic, both in fully associative and in set-associative memories.
Predictive Modeling Techniques of Software Quality from Software Measures
Authors: Taghi M. Khoshgoftaar, John C. Munson, Bibhuti B. Bhattacharya, Gary D. Richardson
Venue: IEEE Transactions on Software Engineering (1992)

The objective in the construction of models of software quality is to use measures that may be obtained relatively early in the software development life cycle to provide reasonable initial estimates of the quality of an evolving software system. Measures of software quality and software complexity to be used in this modeling process exhibit systematic departures of the normality assumptions of regression modeling. Two new estimation procedures are introduced, and their performances in the modeling of software quality from software complexity in terms of the predictive quality and the quality of fit are compared with those of the more traditional least squares and least absolute value estimation techniques. The two new estimation techniques did produce regression models with better quality of fit and predictive quality when applied to data obtained from two software development projects.
A new congestion control scheme: slow start and search (Tri-S)
Authors: Zheng Wang, Jon Crowcroft
Venue: ACM SIGCOMM Computer Communication Review (1991)

Recently there have been many measures proposed to tackle the problem of congestion in computer networks. In this paper, we first analyze some of the measures and then present a new scheme in which the optimal operating point is obtained by evaluation of throughput gradient and resource sharing is adjusted only at the beginning and the end of a connection. Simulation results show that the scheme converges to an optimal operating point quickly and fairly.
Evaluation of compiler optimizations for Fortran D on MIMD distributed memory machines
Authors: Seema Hiranandani, Ken Kennedy, Chau-Wen Tseng
Venue: Proceedings of the 6th international conference on Supercomputing (1992)

The Fortran D compiler uses data decomposition specifications to automatically translate Fortran programs for execution on MIMD distributed-memory machines. This paper introduces and classifies a number of advanced optimizations needed to achieve acceptable performance; they are analyzed and empirically evaluated for stencil computations. Profitability formulas are derived for each optimization. Results show that exploiting parallelism for pipelined computations, reductions, and scans is vital. Message vectorization, collective communication, and efficient coarse-grain pipelining also significantly affect performance.
Percolation theory and computing with faulty arrays of processors
Authors: Thomas R. Mathies
Venue: Proceedings of the third annual ACM-SIAM symposium on Discrete algorithms (1992)

Let H be an n x n mesh-connected array of processors. Each processor is assumed to fail (independently) with probability p. Raghavan [5] gave an algorithm that with high probability routes packets in this mesh with O(log n) dilation and O(log2n) load so long as p &le; 0.29. KKLMRRTT [3] improve the load to O(1) for &ldquo;small&rdquo; p while keeping the O(log n) bound for dilation and showing an o(1) bound for congestion. In this paper we show these bounds hold for p as high as *** 0.4. We also consider the problem where links rather than processors fail and shows these same bounds hold for q < 1/2. In both cases these bounds are tight: for greater probabilities of failure the above embedding bounds cannot be achieved. This short cutoff follows from a zero-one result of percolation theory.
The 21st ACM North American computer chess championship
Authors: Monty Newborn, Danny Kopec
Venue: Communications of the ACM (1991)

After twenty years of traveling from city to city across the United States, the ACM North American Computer Chess Championship came back to the place of its birth, the New York Hilton Hotel, where the competitions began in 1970. This latest five-round event ended in a two-way tie for first place between MEPHISTO and DEEP THOUGHT/88. Finishing in a two-way tie for third place were HITECH and M CHESS. A total of 10 teams participated, and the level of play was at the low grandmaster level. A special three-round end-game championship was won by MEPHISTO, who also captured the prize for the best Small Computing System. A total of $8000 in prizes was divided up among the winners.
Locating a robot with angle measurements
Authors: David Avis, Hiroshi Imai
Venue: Journal of Symbolic Computation (1990)

We consider the problem posed by Sugihara of locating a robot in a planar environment containing n indistinguishable mark points. The robot takes k angular measurements between an unknown subset of mark points. When the robot has a compass, we show that all valid placements of the robot consistent with the measurements may be determined in O(kn^2) time and O(kn) space. When the robot does not have a compass, we show how to determine all valid placements in O(kn^3) time and O(kn) space. We show that with polynomial-time preprocessing both types of location queries can be answered in O(log n) time. For both cases we give bounds on the maximum number of valid placements. We also consider the case where there are image processing errors involved in the angle measurements.
RT-MODULA2: an embedded in MODULA2 language for writing concurrent and real time programs
Authors: Juan Hernández, Juan Antonio Sanchez
Venue: ACM SIGPLAN Notices (1992)

RT-Modula2 is a Modula2 extension for developing concurrent and real-time software. RT-Modula2 gives a simple, estructured and modular way of building concurrent and time depending programs. A new process scheduler has been built, and it has been specially designed for real time processes. This scheduler supports both, ordinary and time depending processes for writing concurrent and real time systems. In this paper, we present key features of RT-Modula2 at the implementation and syntactic level.The actual implementation of RT-Modula2 runs on SUN Workstations and on IBM PCs or compatibles.
Optimal Fault Diagnosis in Comparison Models
Authors: Andrzej Pelc
Venue: IEEE Transactions on Computers (1992)

In comparison models for system-level fault diagnosis, pairs of units are given the same job and results are compared. The result of such a comparison test can be 0 (match) or 1 (mismatch) and diagnosis is based on the collection of test results. Two such models have been studied, among others: the symmetric model of K.Y. Chwa and S.L. Hakimi and the asymmetric model of M. Malek. The worst-case optimal testing algorithms for t-fault detection, sequential t-fault diagnosis, and one-step t-fault diagnosis in both models are presented. Nonadaptive and adaptive testing is discussed and it is shown that the latter often enables one to decrease the number of tests.
Estimating Capacity for Sharing in a Privately Owned Workstation Environment
Authors: Matt W. Mutka
Venue: IEEE Transactions on Software Engineering (1992)

The author analyzes workstation patterns in order to understand opportunities for exploiting idle capacity. This study is based on traces of users workstation activity in a university environment. It identifies two areas where enhancements can be made. One area is the ability of a manager of the shared capacity of a workstation cluster to schedule jobs with deadline constraints. This opportunity is the result of the ability to make good predictions of the time-varying amount of capacity that is available for sharing. A prediction strategy is developed that is shown to have only a small amount of error. For the second area of enhancement, it is shown that it is feasible to allocate partitions of workstations for specific periods. This aids those users who on occasion need exclusive access to several machines. The author examines the profile of periods during which exclusive access to partitions can be given, the rate that owners preempt users of partitions, and the distribution of interpreemption intervals.
Computing sylow subgroups of permutation groups using homomorphic images of centralizers
Authors: Gregory Butler, John Cannon
Venue: Journal of Symbolic Computation (1991)

The ability to construct the Sylow subgroups of a large finite permutation group is fundamental to a number of important algorithms for analysing the structure of such a group. In this paper we describe an algorithm which constructs a Sylow subgroup by restricting the problem to images of centralizers under the natural homomorphisms given by actions on invariant sets and partitions of points. The algorithm is essentially as efficient as that used for computing centralizers in permutation groups.
A time-ordered architecture for integrating reflexive and deliberative behavior
Authors: Lundy M. Lewis
Venue: ACM SIGART Bulletin (1991)

The objective of our research is to establish a universal architecture for effecting an autonomous control logic for land, space, air, and underwater platforms. Although the operational constraints of each platform are diverse, we perceive the general task to be the execution of a mission in an unstructured environment. The task requires reflexive and deliberative mechanisms that sometime trade off problems and sometime combine to solve a single problem. We propose a hierarchical time-ordered architecture for integrating these mechanisms.
Communication Facilities for Distributed Transaction-Processing Systems
Authors: Enrique Mafla, Bharat Bhargava
Venue: Computer (1991)

The study of communication designs in the context of the Raid system, a robust and adaptable distributed database system for transaction processing, is discussed. Related research work on local interprocess communication, remote interprocess communication, and communication protocols for both local area and wide area networks is briefly summarized. A series of experiments on the performance of the facilities available for building the Raid communication software is described. Raid's communication software, called Raidcomm, has evolved as a result of the knowledge gained both from other systems and from the authors' experiments. Several communication services and mechanisms that can be used to make Raid efficient are identified.
Asymptotic eigenfrequency distributions for the N-beam Euler-Bernoulli coupled beam equation with dissipative joints
Authors: Steven G. Krantz, William H. Paulsen
Venue: Journal of Symbolic Computation (1991)

In this paper, we will compute asymptotically the eigenfrequencies of the general collinear Euler-Bemoulli beam equation with linear joints. We will discover in the process that many different types of joints are equivalent, that is, if one joint of a structure is replaced by an equivalent type of joint, the eigenfrequencies to leading order would remain the same for both structures. Also, if the lengths of the beams are rational, there will be a finite number of ''streams'' of eigenfrequencies, each lying asymptotically to a vertical line.
Scheduling Periodic Jobs that Allow Imprecise Results
Authors: Jen-Yao Chung, Jane W. S. Liu, Kwei-Jay Lin
Venue: IEEE Transactions on Computers (1990)

The problem of scheduling periodic jobs in hard real-time systems that support imprecise computations is discussed. Timing faults are avoided in such systems by making available intermediate, imprecise results of acceptable quality when results of the desired quality cannot be produced on time. Two workload models of imprecise computations are presented. These models differ from traditional models in that a task may be terminated any time after it has produced an acceptable result. Each task is logically decomposed into a mandatory part followed by an optional part. In a feasible schedule, the mandatory part of every task is completed before the deadline of the task. The optional part refines the result produced by the mandatory part to reduce the error in the result.