ppxscal/embedding_network huggingface dataset:
Browsing digital video
Authors: Francis C. Li, Anoop Gupta, Elizabeth Sanocki, Li-wei He, Yong Rui
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems (2000)

Video in digital format played on programmable devices presents opportunities for significantly enhancing the user's viewing experience. For example, time compression and pause removal can shorten the viewing time for a video, textual and visual indices can allow personalized navigation through the content, and random-access digital storage allows instantaneous seeks into the content. To understand user behavior when such capabilities are available, we built a software video browsing application that combines many such features. We present results from a user study where users browsed video in six different categories: classroom lectures, conference presentations, entertainment shows, news, sports, and travel. Our results show that the most frequently used features were time compression, pause removal, and navigation using shot boundaries. Also, the behavior was different depending on the content type, and we present a classification. Finally, the users found the browser to be very useful. Two main reasons were: i) the ability to save time and ii) the feeling of control over what content they watched.
Rigid-Body Dynamics with Friction and Impact
Authors: David E. Stewart
Venue: SIAM Review (2000)

Rigid-body dynamics with unilateral contact is a good approximation for a wide range of everyday phenomena, from the operation of car brakes to walking to rock slides. It is also of vital importance for simulating robots, virtual reality, and realistic animation. However, correctly modeling rigid-body dynamics with friction is difficult due to a number of discontinuities in the behavior of rigid bodies and the discontinuities inherent in the Coulomb friction law. This is particularly crucial for handling situations with large coefficients of friction, which can result in paradoxical results known at least since Painlev&eacute; [C. R. Acad. Sci. Paris, 121 (1895), pp. 112--115]. This single example has been a counterexample and cause of controversy ever since, and only recently have there been rigorous mathematical results that show the existence of solutions to his example. The new mathematical developments in rigid-body dynamics have come from several sources: "sweeping processes" and the measure differential inclusions of Moreau in the 1970s and 1980s, the variational inequality approaches of Duvaut and J.-L. Lions in the 1970s, and the use of complementarity problems to formulate frictional contact problems by L&ouml;tstedt in the early 1980s. However, it wasn't until much more recently that these tools were finally able to produce rigorous results about rigid-body dynamics with Coulomb friction and impulses.
Query optimization in the presence of limited access patterns
Authors: Daniela Florescu, Alon Levy, Ioana Manolescu, Dan Suciu
Venue: Proceedings of the 1999 ACM SIGMOD international conference on Management of data (1999)

We consider the problem of query optimization in the presence of limitations on access patterns to the data (i.e., when one must provide values for one of the attributes of a relation in order to obtain tuples). We show that in the presence of limited access patterns we must search a space of annotated query plans, where the annotations describe the inputs that must be given to the plan. We describe a theoretical and experimental analysis of the resulting search space and a novel query optimization algorithm that is designed to perform well under the different conditions that may arise. The algorithm searches the set of annotated query plans, pruning invalid and non-viable plans as early as possible in the search space, and it also uses a best-first search strategy in order to produce a first complete plan early in the search. We describe experiments to illustrate the performance of our algorithm.
Compatible Spectral Approximations for the Velocity-Pressure-Stress Formulation of the Stokes Problem
Authors: M. I. Gerritsma, T. N. Phillips
Venue: SIAM Journal on Scientific Computing (1999)

The numerical approximation of the mixed velocity-pressure-stress formulation of the Stokes problem using spectral methods is considered. In addition to the compatibility condition between the discrete velocity and pressure spaces, a second condition between the discrete velocity and stress spaces must also be satisfied in order to have a well-posed problem. The theory is developed by considering a doubly constrained minimization problem in which the viscous stress tensor is minimized subject to the constraint that the viscous forces are irrotational. The discrete problem is analyzed and error estimates are derived. A comparison between the mixed approach and the standard velocity-pressure formulation is made in terms of the condition number of the resulting systems.
Using Analog Predistortion for Linearizing Class A&ndash;C Power Amplifiers
Authors: Timo Rahkonen, Tapio Kankaala, Marko Neitola, Antti Heiskanen
Venue: Analog Integrated Circuits and Signal Processing (2000)

An analog 5th order, complex-valued polynomial predistortion IC has been built to linearize the behavior of RF power amplifiers. The predistorter can be used either at baseband or low IF frequencies and it was tested using a simple IF amplifier that could be biased to operate in classes A, AB, B and C. Intermodulation products can be reduced by 20 to 30 dB in classes A and AB over a bandwidth of several MHz. In classes B and C the shape of nonlinearity is such that a low-order polynomial predistortion function is not sufficient for linearizing them.
Interaction processes in network supported collaborative concept mapping
Authors: Chiung-Hui Chiu, Chun-Chieh Huang, Wen-Tsung Chang, Tsung-Ho Liang
Venue: ACM SIGCSE Bulletin (1999)

This study investigated group interaction processes in network supported collaborative concept mapping, and the influence of these group interaction processes upon the group concept mapping performance. A total of 36 in-service teachers and pre-service student teachers engaged in this study. It was found that group concept mapping performance was significantly correlated to the quantity of group interaction, particularly high-level interaction processes. Suggestions for a further improvement in the system design to support collaborative concept mapping are also provided in this paper.
A Subspace, Interior, and Conjugate Gradient Method for Large-Scale Bound-Constrained Minimization Problems
Authors: Mary Ann Branch, Thomas F. Coleman, Yuying Li
Venue: SIAM Journal on Scientific Computing (1999)

A subspace adaptation of the Coleman--Li trust region and interior method is proposed for solving large-scale bound-constrained minimization problems. This method can be implemented with either sparse Cholesky factorization or conjugate gradient computation. Under reasonable conditions the convergence properties of this subspace trust region method are as strong as those of its full-space version.Computational performance on various large test problems is reported; advantages of our approach are demonstrated. Our experience indicates that our proposed method represents an efficient way to solve large bound-constrained minimization problems.
Unstable Godunov Discrete Profiles for Steady Shock Waves
Authors: Matthieu Bultelle, Magali Grassin, Denis Serre
Venue: SIAM Journal on Numerical Analysis (1998)

Given a system of n conservation laws ut+f(u)x=0, the steady shock waves, when processed by the Godunov scheme, admit rather simple discrete profiles. One shows that the linear stability of these profiles depends only on the location of the eigenvalues of some endomorphism of an (n-1)-dimensional space. Applying our theory to the gas dynamics with the perfect gas law p=(\ga-1)\rho e$, we construct unstable profiles for values of $\ga$ between 1 and $\ga^*$ and rather strong shocks. Since $\ga^*\in]7/5,5/3[$, our result applies to the air but not to monoatomic gases.Finally, we illustrate this analysis by some numerical experiments, both with $\ga\ga^*$.
VR's frames of reference: a visualization technique for mastering abstract multidimensional information
Authors: Marilyn C. Salzman, Chris Dede, R. Bowen Loftin
Venue: Proceedings of the SIGCHI conference on Human factors in computing systems: the CHI is the limit (1999)

This paper describes a research study that investigated how designers can use frames of reference (egocentric, exocentric, and a combination of the two) to support the mastery of abstract multidimensional information. The primary focus of this study was the relationship between FORs and mastery; the secondary focus was on other factors (individual characteristics and interaction experience) that were likely to influence the relationship between FORs and mastery. This studys outcomes (1) clarify how FORs work in conjunction with other factors in shaping mastery, (2) highlight strengths and weaknesses of different FORs, (3) demonstrate the benefits of providing multiple FORs, and (4) provide the basis for our recommendations to HCI researchers and designers.
The effect of modelling and remodelling on human vertebral body architecture
Authors: Lis Mosekilde
Venue: Technology and Health Care (1998)

Vertebral bone strength is determined by several factors: cortical thickness, bone size, trabecular bone density, and microarchitecture. All these factors change with age as a result of the two dynamic processes: remodelling and modelling. When the changes become pronounced, osteoporotic fractures occur. There is a different aging pattern for men and women: 1. Men achieve a higher peak bone mass than women (mainly because of a larger cross-sectional area of their bones); 2. Men have no accelerated bone loss in middle age; and 3. Men seem to be able to compensate for their loss of cancellous bone strength by increasing their vertebral cross-sectional area with age. The general pattern, for both men and women is, though, that of an extreme (70-80%) decline in whole vertebral body strength during normal aging. The accompanying decline in bone density is much less pronounced (35-45%). This clearly illustrates the power relationship between bone density and strength. However, the role of changes in trabecular bone microarchitecture for vertebral bone strength during aging still needs to be determined.
Linear Scale-Space Theory from Physical Principles
Authors: Alfons H. Salden, Bart M. Ter Haar Romeny, Max A. Viergever
Venue: Journal of Mathematical Imaging and Vision (1998)

In the past decades linear scale-space theory was derived on the basis of various axiomatics. In this paper we revisit these axioms and show that they merely coincide with the following physical principles, namely that the image domain is a Galilean space, that the total energy exchange between a region and its surrounding is preserved under linear filtering and that the physical observables should be invariant under the group of similarity transformations. These observables are elements of the similarity jet spanned by natural coordinates and differential energies read out by a vision system.Furthermore, linear scale-space theory is extended to spatio-temporal images on bounded and curved domains. Our theory permits a delay-operation at the present moment which is in agreement with the motion detection model of Reichardt. In this respect our theory deviates from that of Koenderink which requires additional syntactical operators to realise such a delay-operation.Finally, the semi-discrete and discrete linear scale-space theories are derived by discretising the continuous theories following the theory of stochastic processes. The relation and difference between our stochastic approach and that of Lindeberg is pointed out. The connection between continuous and (semi-)discrete sale-space theory for infinitely high scales observed by Lindeberg is refined by applying appropriate scaling limits. It is shown that Lindeberg&lsquo;s requirement of normalisation for one-dimensional discrete Green&lsquo;s functions can be incorporated into our theory for arbitrary dimensional discrete Green&lsquo;s functions, parameter determination can be avoided, and the requirement of operation at even and odd coordinates sum can be guaranteed simultaneously by taking a normalised linear combination of the identity operator and the first step discrete Green&lsquo;s functions. The new discrete Green&lsquo;s functions are still intimately related to the continuous Green&lsquo;s functions and appear to coincide with pyramidal discrete Green&lsquo;s functions.
Indexing moving points (extended abstract)
Authors: Pankaj K. Agarwal, Lars Arge, Jeff Erickson
Venue: Proceedings of the nineteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2000)

We propose three indexing schemes for storing a set S of N points in the plane, each moving along a linear trajectory, so that a query of the following form can be answered quickly: Given a rectangle R and a real value tq, report all K points of S that lie inside R at time tq. We first present an indexing structure that, for any given constant &egr; > 0, uses O(N/B) disk blocks, where B is the block size, and answers a query in O((N/B)1/2+&egr; + K/B) I/Os. It can also report all the points of S that lie inside R during a given time interval. A point can be inserted or deleted, or the trajectory of a point can be changed, in O(log2B N) I/Os. Next, we present a general approach that improves the query time if the queries arrive in chronological order, by allowing the index to evolve over time. We obtain a trade off between the query time and the number of times the index needs to be updated as the points move. We also describe an indexing scheme in which the number of I/Os required to answer a query depends monotonically on the difference between tq and the current time. Finally, we develop an efficient indexing scheme to answer approximate nearest-neighbor queries among moving points.
When is it Possible to Identify 3D Objects From Single Images Using Class Constraints?
Authors: Ronen Basri, Yael Moses
Venue: International Journal of Computer Vision (1999)

One approach to recognizing objects seen from arbitrary viewpoint is by extracting invariant properties of the objects from single images. Such properties are found in images of 3D objects only when the objects are constrained to belong to certain classes (e.g., bilaterally symmetric objects). Existing studies that follow this approach propose how to compute invariant representations for a handful of classes of objects. A fundamental question regarding the invariance approach is whether it can be applied to a wide range of classes. To answer this question it is essential to study the set of classes for which invariance exists. This paper introduces a new method for determining the existence of invariant functions for classes of objects together with the set of images from which these invariants can be computed. We develop algebraic tests that determine whether the objects in a given class can be identified from single images. These tests apply to classes of objects undergoing affine projection. In addition, these tests allow us to determine the set of views of the objects which are degenerate. We apply these tests to several classes of objects and determine which of them is identifiable and which of their views are degenerate.
A C++ Platform for the Evolution of Trade Networks
Authors: David McFadzean, Leigh Tesfatsion
Venue: Computational Economics (1999)

This paper presents a general C++ platform for the implementation of a trade network game (TNG) that combines evolutionary game play with preferential partner selection. In the TNG, successive generations of resource constrained traders choose and refuse trade partners on the basis of continually updated expected payoffs, engage in risky trades modelled as two-person games, and evolve their trade strategies over time. The modular design of the TNG platform facilitates experimentation with alternative specifications for market structure, trade partner matching, trading, expectation formation, and trade strategy evolution. The TNG platform can be used to study the evolutionary implications of these specifications at three different levels: individual trader attributes, trade network formation, and social welfare.
Voltage scheduling in the IpARM microprocessor system
Authors: Trevor Pering, Thomas Burd, Robert Brodersen
Venue: Proceedings of the 2000 international symposium on Low power electronics and design (2000)

Microprocessors represent a significant portion of the energy conðsumed in portable electronic devices. Dynamic Voltage Scaling (DVS) allows a device to reduce energy consumption by lowering its processor speed at run-time, allowing a corresponding reduction in processor voltage and energy. A voltage scheduler determines the appropriate operating voltage by analyzing application conðstraints and requirements. A complete software implementation, including both applications and the underlying operating system, shows that DVS is effective at reducing the energy consumed withðout requiring extensive software modification.
Solutions to Affine Generalized Equations Using Proximal Mappings
Authors: Stephen C. Billups, Michael C. Ferris
Venue: Mathematics of Operations Research (1999)

The normal map has proven to be a powerful tool for solving generalized equations of the form: find z &#949; C, with 0 &#949; F(z) + NC(z), where C is a convex set and NC(z) is the normal cone to C at z. In this paper, we use the T-map, a generalization of the normal map, to solve equations of the more general form: find z &#949; dom(T), with 0 &#949; F(z) + T(z), where T is a maximal monotone multifunction. We present a path-following algorithm that determines zeros of coherently oriented piecewise-affine functions, and we use this algorithm, together with the T-map, to solve the generalized equation for affine, coherently oriented functions F, and polyhedral multifunctions T. The path-following algorithm we develop here extends the piecewise-linear homotopy framework of Eaves to the case where a representation of a subdivided manifold is unknown.
Spatial Finite Difference Approximations for Wave-Type Equations
Authors: Bengt Fornberg, Michelle Ghrist
Venue: SIAM Journal on Numerical Analysis (1999)

The simplest finite difference approximations for spatial derivatives are centered, explicit, and applied to "regular" equispaced grids. Well-established generalizations include the use of implicit (compact) approximations and staggered grids. We find here that the combination of these two concepts, together with high formal order of accuracy, is very effective for approximating the first derivatives in space that occur in many wave-type PDEs.
Design of a low-power CMOS baseband circuit for wideband CDMA testbed (poster session)
Authors: Chunlei Shi, Yue Wu, Mohammed Ismail
Venue: Proceedings of the 2000 international symposium on Low power electronics and design (2000)

In this paper, the design and performance of a CMOS baseband circuit for WCDMA direct conversion receiver are presented. Consisting of one 5th-order anti-aliasing filter, one 4th-order tunable channel filter, and three variable gain amplifier (VGA) stages, the baseband chain provides 72dB gain range with 2dB gain step and is tunable to select three different bandwidths (from 5MHz to 20MHz radio-frequency spacing). It dissipates only 18mW from a single 3V supply. The input IP3 is 10dBm, and the input-referred noise in the passband is 41nV/$\sqrt{Hz}$.
The active MultiSync controller of the cubetree storage organization
Authors: Nick Roussopoulos, Yannis Kotidis, Yannis Sismanis
Venue: ACM SIGMOD Record (1999)

The Cubetree Storage Organization (CSO)1 logically and physically clusters materialized-views data, multi-dimensional indices on them, and computed aggregate values all in one compact and tight storage structure that uses a fraction of the conventional table-based space. This is a breakthrough technology for storing and accessing multi-dimensional data in terms of storage reduction, query performance and incremental bulk update speed. CSO has been extended with an Active MultiSync controller for synchronizing multiple concurrent access and continuous asynchronous online updates for a non-stop data warehouse.
Two-grid Method for Linear Elasticity on Unstructured Meshes
Authors: Petr Vanek, Marian Brezina, Radek Tezaur
Venue: SIAM Journal on Scientific Computing (1999)

We propose an abstract two-grid algorithm with convergence independent of the coarse-space size. The abstract algorithm is applied to problems of three-dimensional linear elasticity discretized on unstructured meshes. With no regularity assumptions we prove uniform convergence with respect to coarse-space size, domain, essential boundary conditions, and jumps in Young modulus. Numerical experiments confirm the theory and show that the method works well even if some assumptions of the theory are violated.
Efficient atomic broadcast using deterministic merge
Authors: Marcos Kawazoe Aguilera, Robert E. Strom
Venue: Proceedings of the nineteenth annual ACM symposium on Principles of distributed computing (2000)

We present an approach for merging message streams from producers distributed over a network, using a deterministic algorithm that is independent of any nondeterminism of the system, such as the amount of time the messages are delayed by the network, or their arrival order. Thus, if this algorithm is replicated at multiple &ldquo;mergers&rdquo;, then each merger will merge the message streams in exactly the same way. The technique is therefore a solution to atomic broadcast and global atomic multicast [12]. We assume that each producer has access to (approximately) synchronized clocks and can estimate the expected message rates of all producers. We propose an algorithm, called the Bias Algorithm. To measure the performance of the Bias Algorithm, we assume that messages are generated by memoryless processes operating at known message rates, and we measure the expected total merge delay at a given time L. For the case of two producer processes, we give optimal algorithms in this metric, and show that the optimal algorithm converges to our Bias algorithm when L &rArr; &infin;. We reconfirm our optimality result using Dynamic Programming theory, and we use simulations to validate the robustness of this optimality result under more realistic conditions.
Computer Assisted Outcomes Research in Orthopedics: Total Joint Replacement
Authors: Chris Arslanian, Malcolm Bond
Venue: Journal of Medical Systems (1999)

Long-term studies are needed to determine clinically relevant outcomes within the practice of orthopedic surgery. Historically, the patient's subjective feelings of quality of life have been largely ignored. However, there has been a strong movement toward measuring perceived quality of life through such instruments as the SF-36. In a large database from an orthopedic practice results are presented. First, computerized data entry using touch screen technology is not only cost effective but user friendly. Second, patients undergoing hip or knee arthroplasty surgeries make statistically significant improvements in seven of the eight domains of the SF-36 in the first 3 months after surgery. Additional statistically significant improvements over the next 6 to 12 months are also seen. The data are presented here in detail to demonstrate the benefits of a patient outcomes program, to enhance the understanding and use of outcomes data and to encourage further work in outcomes measurement in orthopedics.