ppxscal/embedding_network huggingface dataset:
Recognition of Articulated and Occluded Objects
Authors: Grinnell Jones,  III, Bir Bhanu
Venue: IEEE Transactions on Pattern Analysis and Machine Intelligence (1999)

A model-based automatic target recognition (ATR) system is developed to recognize articulated and occluded objects in Synthetic Aperture Radar (SAR) images, based on invariant features of the objects. Characteristics of SAR target image scattering centers, azimuth variation, and articulation invariants are presented. The basic elements of the new recognition system are described and performance results are given for articulated, occluded and occluded articulated objects and they are related to the target articulation invariance and percent unoccluded.
Deep shadow maps
Authors: Tom Lokovic, Eric Veach
Venue: Proceedings of the 27th annual conference on Computer graphics and interactive techniques (2000)

We introduce deep shadow maps, a technique that produces fast, high-quality shadows for primitives such as hair, fur, and smoke. Unlike traditional shadow maps, which store a single depth at each pixel, deep shadow maps store a representation of the fractional visibility through a pixel at all possible depths. Deep shadow maps have several advantages. First, they are prefiltered, which allows faster shadow lookups and much smaller memory footprints than regular shadow maps of similar quality. Second, they support shadows from partially transparent surfaces and volumetric objects such as fog. Third, they handle important cases of motion blur at no extra cost. The algorithm is simple to implement and can be added easily to existing renderers as an alternative to ordinary shadow maps.
Greedy, Prohibition, and Reactive Heuristics for Graph Partitioning
Authors: Roberto Battiti, Alan Albert Bertossi
Venue: IEEE Transactions on Computers (1999)

New heuristic algorithms are proposed for the Graph Partitioning problem. A greedy construction scheme with an appropriate tie-breaking rule (Min-Max-Greedy) produces initial assignments in a very fast time. For some classes of graphs, independent repetitions of Min-Max-Greedy are sufficient to reproduce solutions found by more complex techniques. When the method is not competitive, the initial assignments are used as starting points for a prohibition-based scheme, where the prohibition is chosen in a randomized and reactive way, with a bias towards more successful choices in the previous part of the run. The relationship between prohibition-based diversification (Tabu Search) and the variable-depth Kernighan-Lin algorithm is discussed. Detailed experimental results are presented on benchmark suites used in the previous literature, consisting of graphs derived from parametric models (random graphs, geometric graphs, etc.) and of ¿real-world¿ graphs of large size. On the first series of graphs, a better performance for equivalent or smaller computing times is obtained, while, on the large ¿real-world¿ instances, significantly better results than those of multilevel algorithms are obtained, but for a much larger computational effort.
Convergence of a Nonconforming Multiscale Finite Element Method
Authors: Yalchin R. Efendiev, Thomas Y. Hou, Xiao-Hui Wu
Venue: SIAM Journal on Numerical Analysis (2000)

The multiscale finite element method (MsFEM) [T. Y. Hou, X. H. Wu, and Z. Cai, Math. Comp., 1998, to appear; T. Y. Hou and X. H. Wu, J. Comput. Phys., 134 (1997), pp. 169--189] has been introduced to capture the large scale solutions of elliptic equations with highly oscillatory coefficients. This is accomplished by constructing the multiscale base functions from the local solutions of the elliptic operator. Our previous study reveals that the leading order error in this approach is caused by the ``resonant sampling,'' which leads to large error when the mesh size is close to the small scale of the continuous problem. Similar difficulty also arises in numerical upscaling methods. An oversampling technique has been introduced to alleviate this difficulty [T. Y. Hou and X. H. Wu, J. Comput. Phys., 134 (1997), pp. 169--189]. A consequence of the oversampling method is that the resulting finite element method is no longer conforming. Here we give a detailed analysis of the nonconforming error. Our analysis also reveals a new cell resonance error which is caused by the mismatch between the mesh size and the wavelength of the small scale. We show that the cell resonance error is of lower order. Our numerical experiments demonstrate that the cell resonance error is generically small and is difficult to observe in practice.
Fast Approximation Methods for Sales Force Deployment
Authors: Andreas Drexl, Knut Haase
Venue: Management Science (1999)

Sales force deployment involves the simultaneous resolution of four interrelated subproblems: sales force sizing, salesman location, sales territory alignment, and sales resource allocation. The first subproblem deals with selecting the appropriate number of salesman. The salesman location aspect of the problem involves determining the location of each salesman in one sales coverage unit. Sales territory alignment may be viewed as the problem of grouping sales coverage units into larger geographic clusters called sales territories. Sales resource allocation refers to the problem of allocating scarce salesman time to the aligned sales coverage units. All four subproblems have to be resolved in order to maximize profit of the selling organization. In this paper a novel nonlinear mixed-integer programming model is formulated which covers all four subproblems simultaneously. For the solution of the model we present approximation methods capable of solving large-scale, real-world instances. The methods, which provide lower bounds for the optimal objective function value, are benchmarked against upper bounds. On average the solution gap, i.e., the difference between upper and lower bounds, is about 3%. Furthermore, we show how the methods can be used to analyze various problem settings of practical relevance. Finally, an application in the beverage industry is presented.
Three semesters of CSO using Java: assignments and experiences
Authors: Elizabeth Odekirk, Dominic Jones, Peter Jensen
Venue: ACM SIGCSE Bulletin (2000)

A CSO class with heavy lab emphasis was developed at the University of Utah in the summer of 1998. It has been taught three times by different instructors to students who were diverse in background, gender, and skill level. The culmination of these efforts is a set of original labs which can be divided into several chronological categories: a gentle introduction, computation and events, interaction and graphical user interfaces, algorithms, object-oriented programming, and Java specific issues. These labs encompassed several themes which guided the curriculum in all three semesters: creativity, visual and interactive methods, and breadth. This paper is a combined summary of these experiences.
The open video project: research-oriented digital video repository
Authors: Gary Geisler, Gary Marchionini
Venue: Proceedings of the fifth ACM conference on Digital libraries (2000)

A future with widespread access to large digital libraries of video is nearing reality. Anticipating this future, a great deal of research is focused on methods of browsing and retrieving digital video, developing algorithms for creating surrogates for video content, and creating interfaces that display result sets from multimedia queries. Research in these areas requires that each investigator acquire and digitize video for their studies since the multimedia information retrieval community does not yet have a standard collection of video to be used for research purposes. The primary goal of the Open Video Project is to create and maintain a shared digital video repository and test collection to meet these research needs.
On Non-Statistical Techniques for Fast Fault Coverage Estimation
Authors: Michael S. Hsiao
Venue: Journal of Electronic Testing: Theory and Applications (1999)

We present fast, dynamic fault coverage estimation techniques for sequential circuits that achieve high degrees of accuracy and significant reductions in the number of injected faults and faulty-event evaluations. In the proposed techniques, we dynamically reduce injection of hyperactive faults as well as faults whose effects never propagate to a flip-flop or primary output. Suppression and over-specification of potential fault-effects are also investigated to reduce faulty-event evaluations. Experiments show that our methods give very accurate estimates with frequently greater speedups than the sampling techniques for most circuits. Most significantly, the proposed techniques can be combined with the sampling approach to obtain speedups comparable to small sample sizes and retain estimation accuracy of large fault samples.
Planetary Motion and the Duality of Force Laws
Authors: Rachel W. Hall, Kresimir Josic
Venue: SIAM Review (2000)

Trajectories of Hooke's law in the complex plane, which are conic sections, are mapped onto trajectories of Newton's law of gravitation via the transformation $z \rightarrow z^2$. Newton's law of ellipses (objects attracted to a center by a force inversely proportional to the square of the distance travel in conic sections) follows from a geometric analysis of this map. An extension of this approach reveals a similar relation between more general pairs of power laws of centripetal attraction. The implications of these relations are discussed and a Matlab program is provided for their numerical study. This material is suitable for an undergraduate complex analysis class.
A microfacet-based BRDF generator
Authors: Michael Ashikmin, Simon Premože, Peter Shirley
Venue: Proceedings of the 27th annual conference on Computer graphics and interactive techniques (2000)

A method is presented that takes as an input a 2D microfacet orientation distribution and produces a 4D bidirectional reflectance distribution function (BRDF). This method differs from previous microfacet-based BRDF models in that it uses a simple shadowing term which allows it to handle very general microfacet distributions while maintaining reciprocity and energy conservation. The generator is shown on a variety of material types.
Design challenges of virtual networks: fast, general-purpose communication
Authors: Alan M. Mainwaring, David E. Culler
Venue: ACM SIGPLAN Notices (1999)

Virtual networks provide applications with the illusion of having their own dedicated, high-performance networks, although network interfaces posses limited, shared resources. We present the design of a large-scale virtual network system and examine the integration of communication programming interface, system resource management, and network interface operation. Our implementation on a cluster of 100 workstations quantifies the impact of virtualization on small message latencies and throughputs, shows full hardware performance is delivered to dedicated applications and time-shared workloads, and shows robust performance under demanding workloads that overcommit interface resources.
A Crosswind Block Iterative Method for Convection-Dominated Problems
Authors: Feng Wang, Jinchao Xu
Venue: SIAM Journal on Scientific Computing (1999)

This paper is on a block iterative algorithm for convection-dominated equations. The algorithm uses crosswind thin blocks in a block Gauss--Seidel method. The relaxation sweep is carried out successively along the downwind direction and exact solvers are used for the block systems. This method is efficient for convection-dominated problems discretized by monotone finite element/finite difference schemes, such as the edge-average finite element method. An optimal partitioning and ordering algorithm, Tarjan's algorithm, is used to partition the nodes into crosswind blocks and order the blocks in the downwind direction. The convergence of this block iterative method is analyzed and exponential convergence rates are proved for both one- and two-dimensional cases on both structured and unstructured meshes. Our empirical and analytical studies indicate that crosswind grouping is essential for the rapid convergence of the method and merely ordering the nodes along the downwind direction is not good enough. Some numerical examples are given to illustrate the effectiveness of the proposed algorithm for convection-dominated problems and to compare it with other popular algorithms.
Document Categorization and Query Generation on the World Wide WebUsing WebACE
Authors: Daniel Boley, Maria Gini, Robert Gross, Eui-Hong (Sam) Han, Kyle Hastings, George Karypis, Vipin Kumar, Bamshad Mobasher, Jerome Moore
Venue: Artificial Intelligence Review (1999)

We present WebACE, an agent for exploring and categorizing documents on the World Wide Web based on a user profile. The heart of the agent is an unsupervised categorization of a set of documents, combined with a process for generating new queries that is used to search for new related documents and for filtering the resulting documents to extract the ones most closely related to the starting set. The document categories are not given a priori. We present the overall architecture and describe two novel algorithms which provide significant improvement over Hierarchical Agglomeration Clustering and AutoClass algorithms and form the basis for the query generation and search component of the agent. We report on the results of our experiments comparing these new algorithms with more traditional clustering algorithms and we show that our algorithms are fast and sacalable.
Speak out and annoy someone: experience with intelligent kiosks
Authors: Andrew D. Christian, Brian L. Avery
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2000)

An intelligent kiosk is a public information kiosk that senses the presence of humans and communicates in a natural way. To examine issues of human-kiosk interaction, we have built and deployed two versions of intelligent kiosks. The first kiosk design combines machine vision to locate and track people in the vicinity with an animated talking head that focuses on clients and talks to them. The second kiosk design uses infrared and sonar sensors to sense clients and multiple interacting agents to communicate with the client. The foremost lessons learned from public trials include (1) people are attracted to an animated face that watches them, (2) small mobile agents interact better with kiosk content than a single fixed face, (3) speaker-independent speech recognition is only useful in targeted applications, and (4) the quality of the content on the kiosk strongly influences the client's evaluation of the quality of the technology.
High Order Infeasible-Interior-Point Methods for Solving Sufficient Linear Complementarity Problems
Authors: Josef Stoer, Martin Wechs, Shinji Mizuno
Venue: Mathematics of Operations Research (1998)

In this paper we develop systematically infeasible-interior-point methods of arbitrarily high order for solving horizontal linear complementarity problems that are sufficient in the sense ofCottle, Pang and Venkateswaran (1989). The results apply to degenerate problems and problem shaving no strictly complementary solution. Variants of these methods are described that eventually avoid recentering steps, and for which all components of the approximate solutions converge superlinearly at a high order, and other variants which even terminate with a solution of the complementarity problem after finitely many steps.
Implementing fast bandwidth smoothing algorithms for the delivery of compressed video streams
Authors: Wu-chi Feng, Chi Chung Lam, Ming Liu
Venue: Journal of High Speed Networks (1998)

Bandwidth smoothing algorithms can effectively reduce the network resource requirements for the delivery of compressed video streams. For stored video, a large number of bandwidth smoothing algorithms have been introduced that are optimal under certain constraints but require access to all the frame size data in order to achieve their optimal properties. This constraint, however, can be both resource and computationally expensive, especially for moderately priced set-top-boxes. In this paper, we introduce a movie approximation technique for the representation of the frame sizes of a video, reducing the complexity of the bandwidth smoothing algorithms and the amount of frame data that must be transmitted prior to the start of playback. Our results show that the proposed approximation technique can accurately approximate the frame data with a small number of piece-wise linear segments without affecting the performance measures that the bandwidth smoothing algorithms are attempting to achieve by more than 1%. In addition, we show that implementations of this technique can speed up execution times by 100 to 1400 times, allowing the bandwidth plans to be calculated in real-time. Evaluation using both a Motion-JPEG encoded video and an MPEG encoded video is provided.
Space-Time Continuous Analysis of Waveform Relaxation for the Heat Equation
Authors: Martin J. Gander, Andrew M. Stuart
Venue: SIAM Journal on Scientific Computing (1998)

Waveform relaxation algorithms for partial differential equations (PDEs) are traditionally obtained by discretizing the PDE in space and then splitting the discrete operator using matrix splittings. For the semidiscrete heat equation one can show linear convergence on unbounded time intervals and superlinear convergence on bounded time intervals by this approach. However, the bounds depend in general on the mesh parameter and convergence rates deteriorate as one refines the mesh.Motivated by the original development of waveform relaxation in circuit simulation, where the circuits are split in the physical domain into subcircuits, we split the PDE by using overlapping domain decomposition. We prove linear convergence of the algorithm in the continuous case on an infinite time interval, at a rate depending on the size of the overlap. This result remains valid after discretization in space and the convergence rates are robust with respect to mesh refinement. The algorithm is in the class of waveform relaxation algorithms based on overlapping multisplittings. Our analysis quantifies the empirical observation by Jeltsch and Pohl [SIAM J. Sci. Comput., 16 (1995), pp. 40--49] that the convergence rate of a multisplitting algorithm depends on the overlap.Numerical results are presented which support the convergence theory.
Embedding Graphs into a Three Page Book with O(m log n) Crossings of Edges over the Spine
Authors: Hikoe Enomoto, Miki Shimabara Miyauchi
Venue: SIAM Journal on Discrete Mathematics (1999)

This paper studies the problem of embedding a graph G into a book with vertices on a line along the spine of the book and edges on the pages in such a way that no edge crosses another. When each edge is allowed to appear in one or more pages by crossing the spine, one of the authors showed that there exists a three page book embedding of G in which each edge crosses the spine at most O(n) times, where n is the number of vertices. This paper improves the result and shows that there exists a three page book embedding of G in which each edge crosses the spine at most O(log n) times. An $\Omega(n^2)$ lower bound on the number of crossings of edges over the spine in any book embedding of the complete graph Kn is also shown.
Optimum Fiducials Under Weak Perspective Projection
Authors: Alfred M. Bruckstein, Robert J. Holt, Thomas S. Huang, Arun N. Netravali
Venue: International Journal of Computer Vision (1999)

We investigate how a given fixed number of points should be located in space so that the pose of a camera viewing them from unknown locations can be estimated with the greatest accuracy. We show that optimum solutions are obtained when the points form concentric complete regular polyhedra. For the case of optimal configurations we provide a worst-case error analysis and use it to analyze the effects of weak perspective approximation to true perspective viewing. Comprehensive computer simulations validate the theoretical results.
Convergence Analysis for Operator-Splitting Methods Applied to Conservation Laws with Stiff Source Terms
Authors: Tao Tang
Venue: SIAM Journal on Numerical Analysis (1998)

We analyze the order of convergence for operator splitting methods applied to conservation laws with stiff source terms. We suppose that the source term $q(u)$ is dissipative. It is proved that the $L^1$ error introduced by the time splitting can be bounded by $O( \D t \Vert q(u_0 )\Vert _{L^1} )$, which is an improvement of the $O( Q \D t )$ upper bound, where $\D t$ is the splitting time step, $Q$ is the Lipschitz constant of $q$, or $Q= \max_{u} \vert q'(u) \vert$ in case $q$ is smooth. A generic model with a special form of stiff source is also investigated. We propose a nonuniform temporal mesh to eliminate the effect of the initial layer introduced by the stiff source term. Our results are derived by using parabolic regularizations, rather than using Kuznetsov's approximation theory, which has been employed as a standard approach for error analysis to the dimensional- or time-splitting methods. Numerical examples are presented to illustrate the theoretical results.
Minimum-Aggregate-Concave-Cost Multicommodity Flows in Strong-Series-Parallel Networks
Authors: J. A. Hoogeveen, T. Kawaguchi, Julie A. Ward
Venue: Mathematics of Operations Research (1999)

This work develops a polynomial-time dynamic-programming algorithm for minimum-aggregate-concave-cost multicommodity flow problems in strong-series-parallel networks. Many important problems from production and inventory management, capacity planning, network design and transportation can be formulated in these terms. Our results include a characterization of extreme flows in strong-series-parallel networks and an algorithm based on this characterization that searches extreme flows efficiently to find an optimal one. The algorithm runs in time proportional to A(N + K), where A, N and K are respectively the numbers of arcs, nodes and commodities in the network, and appears to be the first to solve the problem in polynomial time. When applied to the dynamic economic-order-quantity problem, the algorithm matches the performance of that of Wagner and Whitin (1958). Moreover, our algorithm has broader applications, including the multi-division capacity expansion problem and the generalization of the dynamic economic-order-quantity problem to series-parallel production processes in which subassemblies are assembled into a finished product.
Heat dissipation in wearable computers aided by thermal coupling with the user
Authors: Thad Starner, Yael Maguire
Venue: Mobile Networks and Applications (1999)

Wearable computers and PDA's are physically close to, or are in contact with, the user during most of the day. This proximity would seemingly limit the amount of heat such a device may generate, conflicting with user demands for increasing processor speeds and wireless capabilities. However, this paper explores significantly increasing the heat dissipation capability per unit surface area of a mobile computer by thermally coupling it to the user. In particular, a heat dissipation model of a forearm-mounted wearable computer is developed, and the model is verified experimentally. In the process, this paper also provides tools and novel suggestions for heat dissipation that may influence the design of a wearable computer.