ppxscal/embedding_network huggingface dataset:
Interactive learning in a beginning CS course
Authors: Ashraful A. Chowdhury
Venue: 3C ON-LINE (1995)

The learning ability of students depends on how they learn and on how they acquire the knowledge. Studies indicate that, in general, 11% of people learn through hearing and 83% through sight. Also, people tend to remember 10% of what they read, 20% of what they hear, 30% of what they see, and 90% of what they say as they do things. While these figures are only approximate and subject to exceptions, they do indicate how teaching techniques might be improved.
p-th roots for integers modulo pn and for p-adic integers
Authors: Aldo Volpi
Venue: ACM SIGSAM Bulletin (1995)

Given a prime number p gt; 2, we determine the roots of a polynomial of the form Xp-a in the rings of integers modulo pn and in the ring of p-adic integers, using a procedure based on the solution of first degree equations.
Inversive pseudorandom number generators: concepts, results and links
Authors: Peter Hellekalek
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Stochastic simulation requires a reliable source of randomness. Inversive methods are an interesting and very promising new approach to produce uniform pseudorandom numbers. In this paper, we present evidence that these methods are an important contribution to our toolbox. We survey the outstanding performance of inversive pseudorandom number generators in theoretical and empirical tests, in comparison to linear generators. In addition, this paper contains tables of parameters to implement inversive congruential generators.
Lazy release consistency for hardware-coherent multiprocessors
Authors: Leonidas I. Kontothanassis, Michael L. Scott, Ricardo Bianchini
Venue: Proceedings of the 1995 ACM/IEEE conference on Supercomputing (CDROM) (1995)

Release consistency is a widely accepted memory model for distributed shared memory systems. Eager release consistency represents the state of the art in release consistent protocols for hardware-coherent multiprocessors, while lazy release consistency has been shown to provide better performance for software distributed shared memory (DSM). Several of the optimizations performed by lazy protocols have the potential to improve the performance of hardware-coherent multiprocessors as well, but their complexity has precluded a hardware implementation. With the advent of programmable protocol processors it may become possible to use them after all. We present and evaluate a lazy release-consistent protocol suitable for machines with dedicated protocol processors. This protocol admits multiple concurrent writers, sends write notices concurrently with computation, and delays invalidations until acquire operations. We also consider a lazier protocol that delays sending write notices until release operations. Our results indicate that the first protocol outperforms eager release consistency by as much as 20% across a variety of applications. The lazier protocol, on the other hand, is unable to recoup its high synchronization overhead. This represents a qualitative shift from the DSM world, where lazier protocols always yield performance improvements. Based on our results, we conclude that machines with flexible hardware support for coherence should use protocols based on lazy release consistency, but in a less ''aggressively lazy'' form than is appropriate for DSM.
Oval Designs in Desarguesian Projective Planes
Authors: Laurel L. Carpenter
Venue: Designs, Codes and Cryptography (1996)

Given any projective plane \Pi of even order q containing a hyperoval \cOv, a Steiner 2- ({{q}\choose{2}},\frac{q}{2},1) design can be constructed. The 2-rank of this design is bounded above by { rank}_2(\Pi)-q-1. Using a result of Blokhuis and Moorhouse bm94, we show that this bound is met when\Pi is desarguesian and \cOv is regular. We also show that the block graph of the Steiner 2-design in this case produces a Hadamard design which is such that the binary code of the associated 3-design contains a copy of the first-order Reed-Muller code of length 2^{2m}, where q=2^m.
Processor self-scheduling in parallel discrete event simulation
Authors: Pavlos Konas, Pen-Chung Yew
Venue: Proceedings of the 27th conference on Winter simulation (1995)

This paper describes a novel data structure and an algorithm for processor self-scheduling in parallel discrete event simulation. The presented data structure allows the efficient scheduling of future computations, it facilitates the inexpensive use of processor affinity information, it reduces the contention on the scheduling queue, and it integrates load balancing and locality management methods into a single mechanism. We use the behavioral simulation of a multiprocessor system to characterize the behavior of the proposed data structure and the associated scheduling algorithm. The results of our study show that it is important to maintain as detailed affinity information as possible and exploit this information at run time.
The formal verification of a pipelined double-precision IEEE floating-point multiplier
Authors: Mark D. Aagaard, Carl-Johan H. Seger
Venue: Proceedings of the 1995 IEEE/ACM international conference on Computer-aided design (1995)

Floating-point circuits are notoriously difficult to design and verify. For verification, simulation barely offers adequate coverage, conventional model-checking techniques are infeasible, and theorem-proving based verification is not sufficiently mature. In this paper we present the formal verification of a radix-eight, pipelined, IEEE double-precision floating-point multiplier. The verification was carried out using a mixture of model-checking and theorem-proving techniques in the Voss hardware verification system. By combining model-checking and theorem-proving we were able to build on the strengths of both areas and achieve significant results with a reasonable amount of effort.
A Stable Penalty Method for the Compressible Navier--Stokes Equations: I. Open Boundary Conditions
Authors: J. S. Hesthaven, D. Gottlieb
Venue: SIAM Journal on Scientific Computing (1996)

The purpose of this paper is to present asymptotically stable open boundary conditions for the numerical approximation of the compressible Navier--Stokes equations in three spatial dimensions. The treatment uses the conservation form of the Navier--Stokes equations and utilizes linearization and localization at the boundaries based on these variables.The proposed boundary conditions are applied through a penalty procedure, thus ensuring correct behavior of the scheme as the Reynolds number tends to infinity. The versatility of this method is demonstrated for the problem of a compressible flow past a circular cylinder.
Model Simplification and Optimal Control of Stochastic Singularly Perturbed Systems under Exponentiated Quadratic Cost
Authors: Zigang Pan, Tamer Basar
Venue: SIAM Journal on Control and Optimization (1996)

We study the optimal control of a general class of stochastic singularly perturbed linear systems with perfect and noisy state measurements under positively and negatively exponentiated quadratic cost. The (expected) cost function to be minimized is actually taken as the long-term time average of the logarithm of the expected value of an exponentiated quadratic loss. We identify appropriate ``slow'' and ``fast'' subproblems, obtain their optimum solutions (compatible with the corresponding measurement structure), and subsequently study the performances they achieve on the full-order system as the singular perturbation parameter $\epsilon $ becomes sufficiently small, with the expressions given in all cases being exact to within $O(\sqrt{\epsilon})$. It is shown that the composite controller (obtained by appropriately combining the optimum slow and fast controllers) achieves a performance level close to the optimal one whenever the full-order problem has a solution. The slow controller, on the other hand, achieves (asymptotically, as $\epsilon \to 0$) only a finite performance level (but not necessarily optimal), provided that the fast subsystem is open-loop stable. If the intensity of the noise in the system dynamics decreases to zero, however, the slow controller also achieves a performance level close to the optimal one. The paper also presents a more direct derivation (than heretofore available) of the solution to the linear exponential quadratic Gaussian (LEQG) problem under noisy state measurements, which allows for a general quadratic cost (with cross terms) in the exponent and correlation between system and measurement noises, and obtains both necessary and sufficient conditions for existence of an optimal solution. Such a general LEQG problem is encountered in the slow-fast decomposition of the full-order problem, even if the original problem does not feature correlated noises. In this general context, the paper also establishes a complete equivalence between the LEQG problem and the \hi optimal control problem with measurement feedback, though this equivalence does not extend to the slow and fast subproblems arrived at after time-scale separation.
Some linear and nonlinear methods for pseudorandom number generation
Authors: Harald Niederreiter
Venue: Proceedings of the 27th conference on Winter simulation (1995)

Two principal classes of methods for the generation of uniform pseudorandom numbers can nowadays be distinguished, namely linear and nonlinear methods, and contributions to both types of methods are presented. A very general linear method, the multiple-recursive matrix method, was recently introduced and analyzed by the author. This method includes as special cases several classical methods, and also the twisted GFSR method. New theoretical results on the multiple-recursive matrix method are discussed. Among nonlinear methods, the digital inversive method recently introduced by Eichenauer-Herrmann and the author is highlighted. This method combines real and finite-field arithmetic and, in contrast to other inversive methods, allows a very fast implementation, while still retaining the advantages of inversive methods.
Recoverable sequence transmission protocols
Authors: Ewan D. Tempero, Richard E. Ladner
Venue: Journal of the ACM (JACM) (1995)

We consider the sequence transmission problem, that is, the problem of transmitting an infinite sequence of messages x1x2x3&hellip; over a channel that can both lose and reorder packets. We define performance measures, ideal transmission cost and recovery cost, for protocols that solve the sequence transmission problem. Ideal transmission cost measures the number of packets needed to deliver xn when the channel is behaving ideally and recovery cost measures how long it takes, in terms of number of messages delivered, for the ideal transmission cost to take hold once the channel begins behaving ideally. We also define lookahead, which measures the number of messages the sender can be ahead of the receiver in the protocol. We show that any protocol with constant recovery cost and lookahead requires linear ideal transmission cost. We describe a protocol, Plin, that has ideal transmission cost 2n, recovery cost 1, and lookahead 0.
Weighted Estimation and Tracking for ARMAX Models
Authors: B. Bercu
Venue: SIAM Journal on Control and Optimization (1995)

For complex multivariate ARMAX models, the author studies the weighted least squares algorithm which offers, by the choice of suitable weightings, the advantages of both the extended least squares and the stochastic gradient algorithms. Concerning adaptive tracking problems, the strong consistency of the estimator and control optimality are both ensured. Almost sure rates of convergence are also provided.
Rank $M$ Wavelets with $N$ Vanishing Moments
Authors: Peter Niels Heller
Venue: SIAM Journal on Matrix Analysis and Applications (1995)

This work generalizes the rank 2 (scale factor of 2) orthogonal wavelet sequences of Daubechies to the case of a rank $M$ wavelet matrix. Several equivalent definitions of $N$th order vanishing moments for rank $M$ wavelets are developed. These notions are used to find an explicit formula for rank $M$ wavelet scaling sequences with $N$ vanishing wavelet moments (of degree $N$ in our terminology). A full wavelet matrix (scaling sequence and $M-1$ wavelet sequences) is constructed, with explicit examples.
On the Optimality of Randomized $\alpha$-$\beta$ Search
Authors: Yanjun Zhang
Venue: SIAM Journal on Computing (1995)

It was shown that the expected number of leaves evaluated by randomized $\alpha - \beta$ search for evaluating uniform game trees of degree $d$ and height $h$ is $O((B_d)^h)$ where $B_d = d/2+\ln d+O(1)$. It was shown by Saks and Wigderson [Proceedings of 27th Annual Symposium on Foundations of Computer Science (1986), pp. 29-38] that the optimal branching factor of randomized algorithms for evaluating uniform trees of degree $d$ is $B^{\ast}_d= (d-1+\sqrt{d^2+14d+1}\,)/4= d/2+O(1)$. As $B_d/B^{\ast}_d=1+O(\ln d/d)$, randomized $\alpha$-$\beta$ search is asymptotically optimal for evaluating uniform game trees as the degree of tree increases.
An Integration Scheme for Image Segmentation and Labeling Based on Markov Random Field Model
Authors: Il Y. Kim, Hyun S. Yang
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1996)

This paper presents a unified approach for the image understanding problem based on the MRF models. In the proposed scheme, the image segmentation and interpretation processes cooperate in the simultaneous optimization process so that the erroneous segmentation and misinterpretation can be compensately recovered by continuous estimation of the unified energy function.
Tools for working with guidelines: a CHI '94 special interest group
Authors: A. Cohen, D. Crow, I. Dilli, P. Gorny, H.-J. Hoffman, R. Iannella, K. Ogawa, H. Reiterer, K. Ueno, J. Vanderdonckt
Venue: ACM SIGCHI Bulletin (1995)

This article reports on a Special Interest Group meeting held at CHI '94, Boston, to discuss the past, present, and future of "Tools for Working with Guidelines". Though working with guidelines has gained today more common practice than in the past, it is still not always obvious which methods can be effectively used for managing guidelines during the whole development life-cycle of an interactive application. Moreover, it is not clear which kind of tools could be made available to designers for helping them in the process.This SIG focused on existing and planned tools for working with guidelines and related computer-aided activities involving guidelines: learning, understanding, teaching, illustration, documentation, standard compliance, usability assessment, guidelines evaluation, computer-aided generation of user interfaces explicitly based on guidelines, advice-giving systems.
On Seeing Spaghetti: Self-Adjusting Piecewise Toroidal Recognition of Flexible Extruded Objects
Authors: John R. Kender, Rick Kjeldsen
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1995)

We present a model for flexible extruded objects, such as wires, tubes, or grommets, and demonstrate a novel, self-adjusting, seven-dimensional Hough transform that derives their diameter and three-space curved axes from position and surface normal information. The method is purely local and is inexpensive to compute. The model considers such objects as piecewise toroidal, and decomposes the seven parameters of a torus into three nested subspaces, the structures of which counteract the errors implicit in the analysis of objects of great size and/or small curvature. We believe it is the first example of a parameter space structure designed to cluster ill-conditioned hypotheses together so that they can be easily detected and ignored. This work complements existing shape-from-contour approaches for analyzing tori: It uses no edge information, and it does not require the solution of high-degree non-linear equations by iterative techniques. Most of the results, including the conditions for the existence of more than one solution (phantom ¿anti-tori), have been verified using a symbolic mathematical analysis system. We present, in the environment of the IBM ConVEx system, robust results on both synthetic CAD-CAM range data (the hasp of a lock), and actual range data (a knotted piece of coaxial cable), and discuss several system tuning issues.
Limits on the performance benefits of multithreading and prefetching
Authors: Beng-Hong Lim, Ricardo Bianchini
Venue: ACM SIGMETRICS Performance Evaluation Review (1996)

This paper presents new analytical models of the performance benefits of multithreading and prefetching, and experimental measurements of parallel applications on the MIT Alewife multiprocessor. For the first time, both techniques are evaluated on a real machine as opposed to simulations. The models determine the region in the parameter space where the techniques are most effective, while the measurements determine the region where the applications lie. We find that these regions do not always overlap significantly.The multithreading model shows that only 2-4 contexts are necessary to maximize this technique's potential benefit in current multiprocessors. Multithreading improves execution time by less than 10% for most of the applications that we examined. The model also shows that multithreading can significantly improve the performance of the same applications in multiprocessors with longer latencies. Reducing context-switch overhead is not crucial.The software prefetching model shows that allowing 4 outstanding prefetches is sufficient to achieve most of this technique's potential benefit on current multiprocessors. Prefetching improves performance over a wide range of parameters, and improves execution time by as much as 20-50% even on current multiprocessors. The two models show that prefetching has a significant advantage over multithreading for machines with low memory latencies and/or applications with high cache miss rates because a prefetch instruction consumes less time than a context-switch.
Machine translation divergences: a formal description and proposed solution
Authors: Bonnie J. Dorr
Venue: Computational Linguistics (1994)

There are many cases in which the natural translation of one language into another results in a very different form than that of the original. The existence of translation divergences (i.e., crosslinguistic distinctions) makes the straightforward transfer from source structures into target structures impractical. Many existing translation systems have mechanisms for handling divergent structures but do not provide a general procedure that takes advantage of takes advantage of the systematic relation between lexical-semantic structure and syntactic structure. This paper demonstrates that a systematic solution to the divergence problem can be derived from the formalization of two types of information: (1) the linguistically grounded classes upon which lexical-semantic divergences are based; and (2) the techniques by which lexical-semantic divergences are resolved. This formalization is advantageous in that it facilitates the design and implementation of the system, allows one to make an evaluation of the status of the system, and provides a basis for proving certain important properties about the system.
Extending an interactive thesaurus by dragging
Authors: Eric H. Johnson
Venue: ACM SIGWEB Newsletter (1995)

Some of the research activities of the University of Illinois Digital Library Initiative focus on ways to improve subject access through the use of interactive thesaurus displays. Although a number of thesauri, such as the NASA Thesaurus, have appeared on-line, and eliminate the page-flipping necessary with printed thesauri, they basically just reproduce the printed form in that they do not graphically represent the relationships between thesaurus terms. We have developed a prototype interface, implemented in Microsoft Visual Basic, which visually displays both the hierarchical and related-term structures in a thesaurus. Compare Figures 1 and 2.
An O(n2(m + Nlog n)log n) min-cost flow algorithm
Authors: Zvi Galil, Éva Tardos
Venue: Journal of the ACM (JACM) (1988)

The minimum-cost flow problem is: Given a network with n vertices and m edges, find a maximum flow of minimum cost. Many network problems are easily reducible to this problem. A polynomial-time algorithm for the problem has been known for some time, but only recently a strongly polynomial algorithm was discovered. In this paper an O(n2(m + n log n)log n) algorithm is designed. The previous best algorithm, due to Fujishige and Orlin, had an O(m2(m + nlogn)logn) time bound. Thus, for dense graphs an improvement of two orders of magnitude is obtained. The algorithm in this paper is based on Fujishige's algorithm (which is based on Tardos's algorithm). Fujishige's algorithm consists of up to m iterations, each consisting of O(m log n) steps. Each step solves a single source shortest path problem with nonnegative edge lengths. This algorithm is modified in order to make an improved analysis possible. The new algorithm may still consist of up to m iterations, and an iteration may still consist of up to O(mlogn) steps, but it can still be shown that the total number of steps is bounded by O(n2logn. The improvement is due to a new technique that relates the time spent to the progress achieved.
The Continuum-Armed Bandit Problem
Authors: Rajeev Agrawal
Venue: SIAM Journal on Control and Optimization (1995)

In this paper we consider the multiarmed bandit problem where the arms are chosen from a subset of the real line and the mean rewards are assumed to be a continuous function of the arms. The problem with an infinite number of arms is much more difficult than the usual one with a finite number of arms because the built-in learning task is now infinite dimensional. We devise a kernel estimator-based learning scheme for the mean reward as a function of the arms. Using this learning scheme, we construct a class of certainty equivalence control with forcing schemes and derive asymptotic upper bounds on their learning loss. To the best of our knowledge, these bounds are the strongest rates yet available. Moreover, they are stronger than the $o(n)$ required for optimality with respect to the average-cost-per-unit-time criterion.
Single versus multiple inheritance in object oriented programming
Authors: Ghan Bir Singh
Venue: ACM SIGPLAN OOPS Messenger (1995)

Inheritance is one of the key elements of Object oriented programming. Inheritance is characterized as single or multiple depending on the number of classes a class can inherit from. Single inheritance is simple but restrictive. Multiple inheritance on the other hand is complex but allows a more natural definition of relationships between classes. There has been a significant amount of discussion on the value of multiple inheritance over single inheritance considering the complexity multiple inheritance adds. This paper reviews the two types of inheritance and examines their benefits. The paper then examines the issues and objections that have been raised on the two inheritance mechanisms. Graph, Linear, and Tree oriented implementations of multiple inheritance are reviewed to see how multiple inheritance issues are handled by various object oriented languages.