ppxscal/embedding_network huggingface dataset:
Convergence Properties of Curvature and Torsion
Authors: Farzin Mokhtarian
Venue:  (1990)

Multi-scale, curvature-based shape representation techniques for planar curves and multi-scale, torsion-based shape representation techniques for space curves have been proposed to the computer vision community by Mokhtarian \& Mackworth [1986], Mackworth \& Mokhtarian [1988] and Mokhtarian [1988]. These representations are referred to as the regular, renormalized and resampled curvature and torsion scale space images and are computed by combining information about the curvature or torsion of the input curve at a continuum of detail levels. \n Arc length parametric representations of planar or space curves are convolved with Gaussian functions of varying standard deviation to compute evolved versions of those curves. The process of generating evolved versions of a curve as the standard deviation of the Gaussian function goes from 0 to $\infty$ is referred to as the evolution of that curve. When evolved versions of the curve are computed through an iterative process in which the curve is reparametrized by arc length in each iteration, the process is referred to as arc length evolution. \n This paper contains a number of important results on the convergence properties of curvature and torsion scale space representations. It has been shown that every closed planar curve will eventually become simple and convex during evolution and arc length evolution and will remain in that state. This result is very important and shows that curvature scale space images are well-behaved in the sense that we can always expect to find a scale level at which the number of curvature zero-crossing points goes to zero and know that new curvature zerocrossing points will not be created beyond that scale level which can be considered to be the high end of the curvature scale space image. \n It has also been shown that every closed space curve will eventually tend to a closed planar curve during evolution and arc length evolution and that every closed space curve will eventually enter a state in which new torsion zero-crossing points will not be created during evolution and arc length evolution and will remain in that state. \n Furthermore, the proofs are not difficult to comprehend. They can be understood by readers without an extensive knowledge of mathematics.
OBJECT-ORIENTED RENDERING OF VOLUMETRIC AND GEOMETRIC PRIMITIVES (M.S. Thesis)
Authors: Judith A Challinger
Venue:  (1990)

Computer graphics has, since its inception, been an invaluable tool for the understanding and analysis of datasets, both computed and acquired. The primary means for visualizing abstract datasets has been to extract two or three-dimensional geometric information from the data and display it using traditional computer graphics rendering techniques. However, this technique is not appropriate for many types of datasets and may result in loss of information in the visualization process. Volumetric datasets consist of a three-dimensional grid of scalar and/or vector values which may not be inherently representable using geometric methods. Recently, researchers haved developed specialized techniques for directly rendering volumetric data, however, not many have addressed the need to incorporate these techniques into traditional rendering systems. The objective of this research is to investigate an object-oriented approach to the analysis, design, and implementation of a ray casting rendering system which handles volumetric and geometric primitives directly. Particular attention is paid to the requirement of extensibility of the rendering system. This feature is inherent in an object-oriented design and eases the addition of new types of renderable objects and experimentation with different methods. To demonstrate, the system is extended to include a new primitive for rendering the volumetric results of computational fluid dynamics simulations on three-dimensional curvilinear solution grids.
MORPH: A PROGRAMMER''S GUIDE (Undergraduate Thesis)
Authors: W. P Zola
Venue:  (1991)

Chess has long been used as a testbed for Artificial Intelligence research. There are many good chess playing programs available that perform deep search of the game tree. These programs get their chess-playing power from the depth of the search tree rather than from the sophistication of their position-evaluation heuristics. These programs essentially throw away all the information obtained by evaluating the game tree. This document describes Morph, a chess-playing program based on the completely opposite approach. This program searches only one ply deep and learns from game to game. Morph creates patterns that it uses to evaluate positions that occur in future games. 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
An Alternative to Full Configuration Interaction Based on a Tensor Product Decomposition
Authors: Frederick A. Senese, Christopher A. Beattie, John C. Schug, Jimmy W. Viers, Layne T. Watson
Venue:  (1989)

A new direct full variational approach exploits a tensor (Kronecker) product decompositions of the Hamiltonian. Explicit assembly and storage of the Hamiltonian matrix is avoided by using the Kronecker product structure to form matrix-vector products directly from the molecular integrals. Computation-intensive integral transformations and formula tapes are unnecessary. The wave function is expanded in terms of spin-free primitive sets rather than Slater determinants or configuration state functions and is equivalent to a full configuration interaction expansion. The approach suggests compact storage schemes and algorithms which are naturally suited to parallel and pipelined machines.
Do object-oriented languages need special hardware support?
Authors: Urs Holzle, David Ungar
Venue:  (1995)

Previous studies have shown that object-oriented programs have different execution characteristics than procedural programs, and that special object-oriented hardware can improve performance. The results of these studies may no longer hold because compiler optimizations can remove a large fraction of the differences. Our measurements show that SELF programs are more similar to C programs than are C++ programs, even though SELF is much more radically object-oriented than C++ and thus should differ much more from C. Furthermore, the benefit of tagged arithmetic instructions in the SPARC architecture (originally motivated by Smalltalk and Lisp implementations) appears to be small. Also, special hardware could hardly reduce message dispatch overhead since dispatch sequences are already very short. Two generic hardware features, instruction cache size and data cache write policy, have a much greater impact on performance.
Strokes from Pen-Opposed Extended Edges
Authors: Patrick C Hew, Michael D. Alder
Venue:  (1999)

We perform offline stroke extraction using the correlation between opposing edges of a pen trail. We use a digital filter sized to an estimate of ink thickness, together with the directions across each pen trail. We also infer stroke traversal. Multiple characters can be processed without prior segmentation.
Improved Approximation Algorithms for Embedding Hypergraphs in a Cycle
Authors: Teofilo F. Gonzalez
Venue:  (1998)

Approximation algorithms embedding hypergraphs in a cycle so as to minimize the maximum congestion are presented. Our algorithms generate an embedding by transforming the problem into another problem that can be solved in polynomial time. One transforms it to a Linear Programming (LP) problem, and the other one (LP-Free) to the problem of embedding a graph in a cycle. Both algorithms generate an embedding with congestion at most twice of that in an optimal solution, and we give problem instances for which the solutions generated by both of these algorithms is about twice of optimal. Our problem has applications in CAD and parallel computation.
Probability-one Homotopy Algorithms for Solving the Coupled Lyapunov Equations Arising in Reduced-Order H^2/H^(infinity) Modeling, Estimation, and Control
Authors: Wang Y., Bernstein D. S., Watson L. T.
Venue:  (2000)

Optimal reduced order modeling, estimation, and control with respect to combined H^2/H^(infinity) criteria give rise to coupled Lyapunov and Riccati equations. To develop reliable numerical algorithms for these problems this paper focuses on the coupled Lyapunov equations which appear as a subset of the synthesis equations. In particular, this paper systematically examines the requirements of probability-one homotopy algorithms to guarantee global convergence. Homotopy algorithms for nonlinear systems of equations construct a continuous family of systems and solve the given system by tracking the continuous curve of solutions to the family. The main emphasis is on guaranteeing transversality for several homotopy maps based upon the pseudogramian formulation of the coupled Lyapunov equations and variations based upon canonical forms. These results are essential to the probability-one homotopy approach by guaranteeing good numerical properties in the computational implementation of the homotopy algorithms.
Einbettung von Gitter--Algorithmen in de Bruijn--Graphen
Authors: Michael Nolle, Gerald Schreiber
Venue:  (1993)

In diesem Artikel werden Einbettungen von Gitter-Graphen in de Bruijn- Graphen untersucht. Insbesondere in der digitalen Bildverarbeitng existieren viele parallele Algorithmen deren Kommunikationsverhalten durch einen der beiden Graphen beschreibbar ist. H ufig treten dabei Mischformen auf. Die von uns beschriebene Einbettung hat eine Dilatation von log_2 sqrtN.
Portable and Architecture Independent Parallel Performance Tuning
Authors: S. A. Jarvis, J. M.D. Hill, C. J. Siniolakis, V. P. Vasilev
Venue:  (2001)

A call-graph profiling tool has been designed and implemented to analyse the efficiency of programs written in bsplib. This tool highlights computation and communication imbalance in parallel programs, exposing portions of program code which are amenable to improvement. A unique feature of this profiler is that it uses the BSP cost model, thus providing a mechanism for portable and architecture-independent parallel performance tuning. In order to test the capabilities of the model on a real-world example, the performance characteristics of an SQL query processing application are investigated on a number of different parallel architectures.
Notes on Separability in Metric Sets
Authors: S. G. Matthews
Venue:  (1990)

These notes consider the various topologies over metric sets generated by a selection of the metric axioms given below. In particular we study the separability properties of quasi and partial metric spaces. 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
ARBITRARY RECTILINEAR BLOCK PACKING BASED ON SEQUENCE PAIR STRUCTURE
Authors: Maggie Kang, Wayne W. Dai
Venue:  (1998)

Due to layout or specific physical requirements, macro blocks can be in an arbitrary rectilinear shape. Block packing problem will no longer be limited to the rectangle packing. So far no efficient algorithm has been proposed to solve the general rectilinear block packing problem. This paper presents a novel representation method for arbitrary shaped rectilinear blocks in a sequence pair structure. A sequence pair is feasible if an optimal packing of arbitrary rectilinear blocks can be guaranteed for the given sequence pair regardless of the dimensions of the blocks. In this paper, three conditions are derived on a sequence pair which are necessary and sufficient for a sequence pair to be feasible. Furthermore this paper shows that there always exists a feasible sequence pair for a packing of convex rectilinear blocks. As such, the optimal solution for convex rectilinear block packing can be found by exhausting the finite number of feasible sequence pairs. Three sequence pair operations are developed to incrementally change a solution. Each operation takes linear time and generates a feasible sequence pair. An important theoretical result demonstrates that the optimal solution can always be reachable through a finite times of the sequence pair operations. Therefore a stochastic search based on the three operations can search the feasible solution space both continuously and exhaustively. In such a way, for the first time, the arbitrary shaped rectilinear block packing is solved by using a sequence pair structure.
An Object-oriented Approach to Semidefinite Programming
Authors: Ge Yuzhen, Watson Layne T., Jr Emmanuel G. Collins
Venue:  (1996)

An object-oriented design and implementation of a primal-dual algorithm for solving the semidefinite programming problem is presented. The advantages of applying the object-oriented methodology to numerical computations, in particular to an interior point algorithm for semidefinite programming, or for solving other types of linear matrix inequalities are discussed. One object-oriented design of the primal-dual algorithm and its implementation using C++ is presented. The performance of the C++ implementation is compared with that of a procedural C implementation, and while the performance of the C++ implementation is comparable to that of the C implementation, the resulting code is easier to read, modify, and maintain.
MULTI-MODAL VISUALIZATION OF LOCAL ENVIRONMENT DATA FOR PROTEIN STRUCTURAL ALIGNMENTS
Authors: Marc Hansen, Erik Charp
Venue:  (2001)

We present and evaluate an integrated visualization/sonification environment for analyzing protein structural alignments (superpositions of two or more protein structures in three-dimensional space). We explore how the use of sound can enhance the perception and recognition of specific aspects of the local environment at given positions in the molecular structure represented. Analysis of protein structures is an area in which it is often necessary to examine many variables simultaneously. This is one reason that we chose this field as our data domain. Sonification presents the opportunity to improve understanding of the data both in terms of enhancing or disambiguating parameters which are already represented visually, and perhaps more importantly, in extending the number of variables that may be represented simultaneously, particularly by the inclusion of features that are difficult to represent visually. In order to maximize the ability of our sonifications to represent data, we used voices and melodic components that were very distinct. We also used several musical effects such as panning a voice to the left or right speaker, or changing a voice''s volume to maximize the individuality of the sonification elements. In addition to enhancing the perception of data features presented visually, we also strove to make our sonifications pleasing and musically idiomatic.
The Translation of High-Level Functional Languages to FLIC
Authors: M. S. Joy
Venue:  (1989)

FLIC is designed as a "standardised" intermediate-level functional language. It is an interface between high-level functional languages and implementation software, so that with a single FLIC implementation many high-level functional languages can be supported. In this paper we examine some aspects of the translation of high-level functional languages to FLIC, with specific reference to two translators - one from FP, one from SASL.
Exploiting Commuting Operations in Parallelizing Serial Programs
Authors: Pedro Diniz, Martin Rinard
Venue:  (1995)

Two operations commute if the result of their execution is independent of the order in which they execute. Commuting operations can be executed concurrently provided they execute atomically on the objects they access. Statically recognizing commuting operations is of great interest because they increase the amount of concurrency a compiler can exploit. In this document we introduce commutativity analysis - a new technique for automatically parallelizing serial programs. We then conduct a feasibility study of existing scientific applications as to the existence and exploitability of commuting operations. We study the commuting operations present in one such application - the Barnes-Hut hierarchical N-body algorithm. We then parallelize this application using knowledge of commuting operations and present performance results of the parallel code for a shared-memory multiprocessor.
EXTRACTING TIME-OF-FLIGHT DELAY FROM SCATTERING PARAMETER BASED MACROMODEL
Authors: Haifang Liao, Wayne W Dai
Venue:  (1993)

A novel and efficient method for transient analysis of interconnect systems is presented. The method is based on the scattering parameter technique. By extracting the propagation delay of the lossy transmission line and developing an efficient network reduction method, we compute the lower order model of the interconnect system for evaluating the exponentially charging time, keeping track of time-of-flight delay. The accuracy of the system response can be greatly improved from the extraction of the time-of-flight.
The File System of a Logic Operating System
Authors: Anthony J. Kusalik
Venue:  (1984)

This paper describes the file system of an operating system for a logic inference machine. The file system is composed of a file system device and a collection of file system servers. The former provides the basic services of creation, access (reading or writing), removal, and stable storage of files. It realizes a simple, though powerful model: a file store as a special type of name server maintaining associations between identifiers and entities. A file is then a pair, $$, of terms. Clients gain access to a file by sharing the file content term with the file system device. Reading the file corresponds to examination of the term; writing, to instantiation. There is no need of explicit read or write operations, or of file closure. File system servers enhance or modify this basic file abstraction. They can provide features of more conventional file systems, such as hierarchical directories or fixed, structured file formats. Concurrent Prolog is assumed as the underlying machine language and the operating system implementation language. However, the ideas are also applicable to other parallel logic programming languages, such as PARLOG. As a prerequisite to describing the file system, the Concurrent Prolog machine model is presented, as well as an overview of the entire operating system design.
Representation with Receptive Fields
Authors: Y. Weiss, S. Edelman
Venue:  (1993)

Receptive fields are probably the most prominent and ubiquitous computational mechanism employed by biological information processing systems. We report an attempt to understand the representational capabilities of the kind of receptive fields found in mammalian vision motivated by the assumption that the successive stages of processing remap the retinal representation space in a manner that makes objectively similar stimuli (e.g., different views of the same 3D object) closer to each other, and dissimilar stimuli farther apart. We present theoretical analysis and computational experiments that compare the similarity between stimuli as they are represented at the successive levels of the processing hierarchy, from the retina to the nonlinear cortical units. Our results indicate that population-based codes do convey information that seems lost in the activities of the individual receptive fields, and that at the higher levels of the hierarchy objects may be represented in a form that is more useful for visual recognition. This finding may, therefore, explain the success of previous empirical approaches to object recognition that employed representation by localized receptive fields.
CHARACTERIZATIONS OF LEARNABILITY FOR CLASSES OF {0,...,N}-VALUED FUNCTIONS
Authors: Shai Ben-David, Nicolo Cesa-Bianchi, David Haussler, Philip Long
Venue:  (1993)

We investigate the PAC learnability of classes of {0,...,n}-valued functions. For n = 1 it is known that the finiteness of the Vapnik- Chervonenkis dimension is necessary and sufficient for learning. In this paper we present a general scheme for extending the VC-dimension to the case n < 1. Our scheme defines a wide variety of notions of dimension in which several variants of the VC-dimension, previously introduced in the context of learning, appear as special cases. Our main result is a simple condition characterizing the set of notions of dimension whose finiteness is necessary and sufficient for learning. This provides a variety of new tools for determining the learnability of a class of multi-valued functions. Our characterization is also shown to hold in the "robust" variant of PAC model and for any "reasonable" loss function.
Union of Spheres Model for Volumetric Data
Authors: Vishwa Ranjan, Alain Fournier
Venue:  (1995)

A stable representation of an object means that the representation is unique, is independent of the sampling geometry, resolution, noise, and other small distortions in the data, and is instead linked to the shape of the object. Stable representations help characterize shapes for comparison or recognition; skeletal (or medial axis) and volumetric primitive models have been popular in vision for the same reason. Piecewise polyhedral representations, e.g., tetrahedra, and voxel representations, e.g., octrees, generally tend to be unstable. We propose a representation for 3D objects based on the set union of overlapping sphere primitives. This union of spheres (UoS) model has some attractive properties for computer graphics, computational vision, and scientific visualization.
Protein Folding, Spin Glass and Computational Complexity
Authors: A. S. Fraenkel
Venue:  (1997)

A reduction from ``Ground State of Spin Glass'''' in statistical mechanics to a minimum-energy model of protein folding is made, which shows that the latter is NP-complete (high complexity). The reduction approximates true folding of a protein. The method also enables to show that even if the backbone of the protein is fixed, the folding of the side-chains is NP-complete. In a separate second part, the possibility of synthesizing proteins to solve arbitrary instances of the spin glass problem is speculated upon.
Applying Software Engineering Principles to Process Modeling
Authors: Joel Henry
Venue:  (1992)

Process models are constructed using specific modeling methods or techniques. These techniques impart certain characteristics to the models they produce. Application of the software engineering principles of information hiding, top-down functional decomposition and stepwise refinement to process modeling imparts many desirable characteristics to the process models produced. This paper describes an approach to process modeling which applies these software engineering principles to control flow diagrams in order to produce software process models.
Anisotropic Diffusion of Subdivision Surfaces and Functions on Surfaces
Authors: Chandrajit L. Bajaj, Guoliang Xu
Venue:  (2001)

In this paper we treat discrete data (2-manifold) in IR 3 and function data defined on the surface. A surface and a k-3 dimensional function vector data on the surface can be considered as a discretization of a 2-manifold embedded in IRk. We establish a unified anisotropic diffusion model for such manifolds aiming at smoothing (fairing) out noise both in the 2-manifold in IR3 and the 2-manifold in IRk, while enhancing curve features on both 2-manifolds. We combine the C1 limit function representation of Loop''s subdivision for triangular surface meshes and vector functions on the surface mesh with anisotropic diffusion in a parameterized time setting, to arrive at a sparse linear system of equations. Iteratively, solving the sparse linear system, yields a sequence of faired (smoothed) meshes as well as faired function with specified feature curves, enhanced.