ppxscal/embedding_network huggingface dataset:
DUALITY BETWEEN L-BASES AND B-BASES
Authors: Suresh Lodha, Ron Goldman
Venue:  (1995)

L-bases and B-bases are two important classes of polynomial bases used for representing surfaces in CAGD. The Bezier and multinomial bases are special cases of both L-bases and B-bases. We establish that certain proper subclasses of bivariate Lagrange and Newton bases are L-bases and certain proper subclasses of power and Newton dual bases are B-bases. A geometric point-line duality between B-bases and L-bases is described and used to investigate the duality between geometric representations for bivariate Bezier and multinomial bases, Lagrange and power bases, and Newton and Newton dual bases for surfaces. Under this geometric duality, lines in L-bases correspond to points or vectors in B-bases and concurrent lines map to collinear points and vice-versa. The generalized de Boor-Fix formula for surfaces also provides an algebraic duality between L-bases and B-bases. This algebraic duality between B-bases and L-bases can be used to develop change of basis algorithms between any two of these bases. We describe, in particular, a change of basis algorithm from a bivariate Lagrange L-basis to a bivariate Bezier basis.
A Syntactic Approach to the Recognition of Common cardiac Arrhythmias within a Single Ambulatory ECG trace.
Authors: Arkell
Venue:  (1993)

Abstract unavailable. 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
Unit Disk Graph Recognition is NP-Hard*
Authors: Heinz Breu, David Kirkpatrick
Venue:  (1993)

Unit disk graphs are the intersection graphs of unit diameter closed disks in the plane. This paper reduces SATISFIABILITY to the problem of recognizing unit disk graphs. Equivalently, it shows that determining if a graph has sphericity 2 or less, even if the graph is planar or is known to have sphericity at most 3, is NP-hard. We show how this reduction can be extended to 3 dimensions, thereby showing that unit sphere graph recognition, or determining if a graph has sphericity 3 or less, is also NP-hard. We conjecture that K-sphericity is NP-hard for all fixed K greater than 1.
UDS: A UNIVERSAL DATA STRUCTURE
Authors: Robert Levinson
Venue:  (1994)

This paper gives a data structure (UDS) for supporting database retrieval, inference and machine learning that attempts to unify and extend previous work in relational databases, semantic networks, conceptual graphs, RETE, neural networks and case-based reasoning. Foundational to this view is that all data can be viewed as a primitive set of objects and mathematical relations (as sets of tuples) over those objects. The data is stored in three partially-ordered hierarchies: a node hierarchy, a relation hierarchy, and a conceptual graphs hierarchy. All three hierarchies can be stored as "levels" in the conceptual graphs hierarchy. These multiple hierarchies support multiple views of the data with advantages over any of the individual methods. In particular, conceptual graphs are stored in a relation-based compact form that facilitates matching. UDS is currently being implemented in the Peirce conceptual graphs workbench and is being used as a domain-independent monitor for state-space search domains at a level that is faster than previous implementations designed specifically for those domains.In addition it provides a useful environment for pattern-based machine learning.
Mammography: A Simplified Scientific and Medical Background
Authors: R. Chandrasekhar
Venue:  (1994)

Abstract unavailable. 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
SPHERE PACKING NUMBERS FOR SUBSETS OF THE BOOLEAN n-CUBE WITH BOUNDED VAPNIK-CHERVONENKIS DIMENSION
Authors: David Haussler
Venue:  (1991)

Let V contained in {0,1}^n have Vapnk-Chervonenkis dimension d. Let M(k/n,V) denote the cardinality of the largest W contained in V such that any two distinct vectors in W differ on at least k indices. We show that M(k/n,V) >= (cn/(k+d))^d for some constant c. This improves on the previous best result of ((cn/k)log(n/k))^d. This new result has applications in the theory of empirical processes.
SELECTIVE VICTIM CACHING: A METHOD TO IMPROVE THE PERFORMANCE OF DIRECT-MAPPED CACHES
Authors: Dimitrios Stiliadis, Anujan Varma
Venue:  (1994)

Although direct-mapped caches suffer from higher miss ratios as compared to set-associative caches, they are attractive for today''s high-speed pipelined processors that require very low access times. Victim caching was proposed by Jouppi (Jouppi-91) as an approach to improve the miss rate of direct-mapped caches without affecting their access time. This approach augments the direct-mapped main cache with a small fully-associate cache, called victim cache, that stores cache blocks evicted from the main cache as a result of replacements. We propose and evaluate an improvement of this scheme, called `selective victim caching''. In this scheme, incoming blocks into the first-level cache are placed selectively in the main cache or a small victim cache by the use of a prediction scheme based on their past history of use. In addition, interchanges of blocks between the main cache and the victim cache are also performed selectively. We show that the scheme results in significant improvements in miss rate as well as the average memory access time, for both small and large caches (4 Kbytes -- 128 Kbytes). For example, simulations with 10 instruction traces from the SPEC ''92 benchmark suite showed an average improvement of approximately 21 percent in miss rate over simple victim caching for a 16-Kbyte cache with a block size of 32 bytes; the number of blocks interchanged between the main and victim caches reduced by approximately 70 percent. Implementation alternatives for the scheme in an on-chip processor cache are also described.
The Creation, Presentation and Implications of Selected Auditory Illusions
Authors: Scott Flinn, Kellogg S. Booth
Venue:  (1995)

This report describes the initial phase of a project whose goal is to produce a rich acoustic environment in which the behaviour of multiple independent activities is communicated through perceptually distinguishable auditory streams. While much is known about the perception of isolated auditory phenomena, there are few general guidelines for the selection of auditory elements that can be composed to achieve a display that is effective in situations where the ambient acoustic conditions are uncontrolled. Several auditory illusions and effects are described in the areas of relative pitch discrimination, perception of auditory streams, and the natural association of visual and auditory stimuli. The effects have been evaluated informally through a set of demonstration programs that have been presented to a large and varied audience. Each auditory effect is introduced, suggestions for an effective demonstration are given, and our experience with the demonstration program is summarized. Implementation issues relevant to the reproduction of these effects on other platforms are also discussed. We conclude by describing several experiments aimed at resolving issues raised by our experience with these effects.
Path-Based Target Prediction for File System Prefetching
Authors: Brian S. White, Kevin Skadron
Venue:  (2000)

Prefetching is a well-known technique for mitigating the von Neumann bottleneck. In its most rudimentary form, prefetching simplifies to sequential lookahead. Unfortunately, large classes of applications exhibit file access patterns that are not amenable to sequential prefetching. More general purpose approaches often use models to develop an appropriate prefetching strategy. Such models tend to be large, thus preventing a kernel implementation which would lead to user transparency and more efficient execution. This work applies the target cache approach of path-based branch target prediction to file system prefetching to combat these deficiencies. The feasibility and worth of such a design are evaluated against a number of parallel applications popular in the scientific community.
A survey of evolutionary algorithms for data mining and knowledge discovery
Authors: Alex A. Freitas
Venue: Advances in evolutionary computing: theory and applications (2003)

This chapter discusses the use of evolutionary algorithms, particularly genetic algorithms and genetic programming, in data mining and knowledge discovery. We focus on the data mining task of classification. In addition, we discuss some preprocessing and postprocessing steps of the knowledge discovery process, focusing on attribute selection and pruning of an ensemble of classifiers. We show how the requirements of data mining and knowledge discovery influence the design of evolutionary algorithms. In particular, we discuss how individual representation, genetic operators and fitness functions have to be adapted for extracting high-level knowledge from data.
A FURTHER NOTE ON HENNESSY''S ``SYMBOLIC DEBUGGING OF OPTIMIZED CODE''''
Authors: Max Copperman, Charles E. McDowell
Venue:  (1992)

When attempting to debug optimized programs, most debuggers may give misleading information about the value of variables at breakpoints. Hennessy proposed a set of algorithms for generating optimized code and determining when, in the generated code, the reported values would be misleading, and under certain circumstances actually recovering the ``expected'''' value of the variable (i.e., one that would not be misleading). We point out where the assumptions made by Hennessy need to be revised due to advances in compiler and debugger technology, and give references for current work on this revised problem. ([To appear in TopLas.]supersedes 91-04)
Methods for Transferring Results of Innovative Research in Computer-Based Instruction to Academia and Industry
Authors: J. Michael Spector
Venue: Journal of Computing Sciences in Colleges (1991)

It is a common and popular criticism that education is declining in the United States. Several studies exist which in fact support this criticism. Possible solutions to the crisis in education are numerous. One family of solutions involves accelerating the process of transferring the results of educational research into academia and industry. This paper describes several particular ways of doing this with regard to educational research involving computer-based instruction (CBI). The methods for accelerated transfer described here are interesting from an educational perspective because they indicate that it is possible to treat educational institutions as full partners in industry research and development efforts. The methods and examples are interesting from a computer science perspective because they describe techniques for building data collection into software for the specific purpose of refining the software. Data collected could be used in the field to dynamically modify the look and feel of an interface or it could be used in the laboratory to refine the application product. The results reported herein are encouraging and indicate that these methods might be applied more widely.
An Empirical Study of Reuse, Quality, and Productivity
Authors: Frakes William, Succi Giancarlo
Venue:  (1997)

This paper presents an analysis of four sets of industrial data to determine if software reuse is correlated with higher levels of software quality and productivity.
Evaluating Definitive Principles for Interaction in Graphics
Authors: W. M. Beynon
Venue:  (1988)

This paper is an appraisal of current progress towards supporting interactive graphics within the framework of a general-purpose programming paradigm based upon definitions. It considers how the use of definitive principles relates to other work, why it appears promising, and what progress has been made towards the resolution of technical difficulties. It re-examines potential for applications of definitive principles in interactive graphics in the light of more recently developed ideas about dealing with control issues and dynamically changing relationships in a definitive programming framework. It also takes account of new research into notations for graphics that makes use of geometrical constructions. As a subsidiary theme, the paper contrasts the support for reference and representation of geometric relationships in various kinds of interactive graphics systems.
A real-coded genetic algorithm using the unimodal normal distribution crossover
Authors: Isao Ono, Hajime Kita, Shigenobu Kobayashi
Venue: Advances in evolutionary computing: theory and applications (2003)

This chapter presents a real-coded genetic algorithm using the Unimodal Normal Distribution Crossover (UNDX) that can efficiently optimize functions with epistasis among parameters. Most conventional crossover operators for function optimization have been reported to have a serious problem in that their performance deteriorates considerably when they are applied to functions with epistasis among parameters. We believe that the reason for the poor performance of the conventional crossover operators is that they cannot keep the distribution of individuals unchanged in the process of repetitive crossover operations on functions with epistasis among parameters. In considering the above problem, we introduce three guidelines, 'Preservation of Statistics', 'Diversity of Offspring', and 'Enhancement of Robustness', for designing crossover operators that show good performance even on epistatic functions. We show that the UNDX meets the guidelines very well by a theoretical analysis and that the UNDX shows better performance than some conventional crossover operators by applying them to some benchmark functions including multimodal and epistatic ones. We also discuss some improvements of the UNDX under the guidelines and the relation between real-coded genetic algorithms using the UNDX and evolution strategies (ESs) using the correlated mutation.
Simplifying Terrain Models and Measuring Terrain Model Accuracy
Authors: David S Andrews
Venue:  (1996)

We describe a set of TIN simplification methods that enable the use of the triangulation hierarchy introduced by Kirkpatrick and modified by de Berg and Dobrindt. This triangulation hierarchy can be used to form a terrain model combining areas with varying levels of detail. One variant of the delete simplification method formed simplifications with accuracy close to the greedy method. We also investigated different variables that can be used to measure the accuracy of our simplified terrain models. Although the use of derivative statistics did not significantly alter our evaluation of the performance of our simplification methods, we recommend that any future comparisons should be aware of these alternative variables of surface characterization.
When Can Two Unsupervised Learners Achieve PAC Separation?
Authors: Paul Goldberg
Venue:  (2000)

In this paper we introduce a new framework for studying PAC learning problems, that has practical as well as theoretical motivations. In our framework the training examples are divided into the two sets associated with the two possible output labels, and each set is sent to a separate (unsupervised) learner. The two learners must independently fit probability distributions to their examples, and afterwards these distributions are combined to form a hypothesis by labeling test data according to maximum likelihood. That is, the output label for any input would be the one associated with the unsupervised learner that gave that input the higher probability. This approach is motived by the observation that PAC learning algorithms of this kind are extendable in a natural way to multi-class classification. It also turns out to introduce new algorithmic challenges, even for very simple concept classes. Learning may be viewed as a cooperative game between two players, for which we must design a strategy that they will both use. Within the framework, we give algorithms for learning various simple geometric concept classes. In the boolean domain we show how to learn parity functions, and functions for which there is a constant upper bound on the number of relevant attributes. We give an algorithm for learning monomials subject to the assumption that the input distribution is a product distribution. The main open problem is whether monomials (or any other concept class) distinguish learnability in this framework from standard PAC-learnability.
Capturing and Executing Behavioral Requirements: The Play-In/Play-Out Approach,
Authors: D. Harel, R. Marelly
Venue:  (2001)

A powerful methodology for specifying scenario-based requirements of reactive systems is described, in which the behavior is ``played in" directly from the system''s GUI or some abstract version thereof, and can then be ``played out". The approach is supported and illustrated by a tool, which we call the play-engine. As the requirements are played in, the play-engine automatically generates a formal version in the language of live sequence charts (LSCs). As they are played out, it causes the application to react according to the universal (``must") parts of the specification; the existential (``may") parts can be monitored to check their successful completion. Play-in is a user-friendly high-level way of specifying behavior and play-out is a rather surprising way of working with a fully operational system directly from its requirements. The ideas appear to be relevant to many stages of system development, including requirements engineering, specification, testing, analysis and implementation.
A High-School Program in Computer Science
Authors: J. Gal-Ezer, C. Beeri, D. Harel, A. Yehudai
Venue:  (1994)

The authors are part of a committee that has been designing a new high-school curriculum in computer science and supervising the preparation of a comprehensive study program based on it. The new program emphasizes the foundations of algorithmic thinking, and teaches programming as a way to get the computer to carry out an algorithm. The paper discusses the program and its initial implementation.
TYPE-SPECIFIC STORAGE MANAGEMENT (PH.D. Thesis)
Authors: Daniel Edelson
Venue:  (1993)

This dissertation explores the limits of integrating garbage collection (GC) and other memory management techniques into `industrial-strength'' statically-typed object-oriented programming languages (OOPLs). GC cannot entirely replace man- ual reclamation in such languages. However, providing GC as an alternative has many benefits. We discuss various aspects of the integration of garbage collectors into programming languages such as C++. This thesis includes: - a comparison of the behavior of smart pointers with that of normal pointers, and examples of how smart pointers help integrate compiler- independent memory management algorithms into a program; - a presentation of fault interpretation, which is a technique for improv- ing certain algorithms (including some generational garbage collection algorithms) through a novel use of virtual memory protection, and, - a discussion of the memory management components we provide, which include: two garbage collectors, a precompiler and additional tools.
Library Access, Search and Retrieval (LASR) Pilot (Final Report)
Authors: James C. French, Glen L. Bull, Martha R. Tarrant, Allison L. Powell
Venue:  (1996)

The Global Change Data and Information System (GCDIS) is a cooperative effort among eight United States government agencies and other organizations to provide public Internet access to their global change resources. The Library Access, Search and Retrieval (LASR) pilot project focused on in-library use of these resources, testing the GCDIS with the public from September, 1994 - December, 1995 in order to solicit information about the system''s usefulness in its current state and suggestions which might be employed in the continued evolution and revision of it. This document is the final report of the LASR project.
Dimensionality Reduction for Similarity Searching in Dynamic Databases
Authors: K. V. R Kanth, Divyakant Agrawal, Amr El Abbadi, Ambuj Singh
Venue:  (1998)

Databases are increasingly being used to store multi-media objects such as maps, images, audio and video. Storage and retrieval of these objects is accomplished using multi-dimensional index structures such as R*-trees and SS-trees. As dimensionality increases, query performance in these index structures degrades. This phenomenon, generally referred to as the dimensionality curse, can be circumvented by reducing the dimensionality of the data. Such a reduction is however accompanied by a loss of precision of query results. Current techniques such as QBIC use SVD transform-based dimensionality reduction to ensure high query precision. The drawback of this approach is that SVD is expensive to compute, and therefore not readily applicable to dynamic databases. In this paper, we propose novel techniques for performing SVD-based dimensionality reduction in dynamic databases. When the data distribution changes considerably so as to degrade query precision, we recompute the SVD transform and incorporate it in the existing index structure. For recomputing the SVD-transform, we propose a novel technique that uses aggregate data from the existing index rather than the entire data. This technique reduces the SVD-computation time without compromising query precision. We then explore efficient ways to incorporate the recomputed SVD-transform in the existing index structure without degrading subsequent query response times. These techniques reduce the computation time by a factor of 20 in experiments on color and texture image vectors. The error due to approximate computation of SVD is less than 10%.
Computing Almost Shortest Paths,
Authors: M. Elkin
Venue:  (2001)

We study the s-sources almost shortest paths (shortly, s-ASP) problem. Given an unweighted graph G = (V,E), and a subset S of s nodes, the goal is to compute almost shortest paths between all the pairs of nodes S &#x00D7;V. The particular case when S = V is known as the all pairs almost shortest paths (shortly, APASP ) problem. We devise an algorithm with running time O(|E|nr + s ?n1 + z) for this problem that computes the paths P>sub<u,w>/sub< for all pairs (u,w) I S &#x00D7;V such that the length of P>sub<u,w>/sub< is at most (1 + e) d>sub<G>/sub<(u,w) + b(z,r,e), and b(z,r,e) is constant when z, r and e are (one can choose arbitrarily small constants z, r and e). Our algorithm also guarantees an upper bound of O(n1 + z) on the overall number of edges used used by all the computed paths P>sub<u,w>/sub<. We also devise an efficient algorithm for constructing (1 + e,b(z,r,e))-spanners with O(n1 + z) edges. A subgraph H I E is an (a,b)-spanner of the graph G = (V,E), if for any pair of nodes u,w I V, d>sub<H>/sub<(u,w) # a?d>sub<G>/sub<(u,w) + b. We present an algorithm with running time of O(|E| nr) that constructs an (1 + e, b(z, r,e))-spanners with O(n1 + z) edges. It is significantly faster than the previously known algorithm, whose running time is [O\tilde](n2 + z). We devise efficient distributed protocols that implement all our sequential algorithms. Also, we extend our results to the weighted graphs.
OBDD''s LTL MC Model Checking of Linear TL, Using OBDD''s
Authors: Y. Kesten, A. Pnueli, L. Raviv
Venue:  (1995)

In this straightforward paper we present algorithms for checking satisfiability and satisfiability over a finite-state fair transition system (model checking) of full (past included) propositional linear-time temporal logic, using OBDD''s. In checking satisfiability over a fair transition system we take into account the full set of fairness requirements, including justice (weak fairness) and compassion (strong fairness). For the case that the formula is found to be satisfiable or satisfiable over a finite-state program, we describe algorithms that extract a satisfying model.