ppxscal/embedding_network huggingface dataset:
Fast video segment retrieval by sort-merge feature selection, boundary refinement, and lazy evaluation
Authors: Yan Liu, John R. Kender
Venue: Computer Vision and Image Understanding (2003)

We present a fast video retrieval system with three novel characteristics. First, it exploits the methods of machine learning to construct automatically a hierarchy of small subsets of features that are progressively more useful for indexing. These subsets are induced by a new heuristic method called Sort-Merge feature selection, which exploits a novel combination of Fastmap for dimensionality reduction and Mahalanobis distance for likelihood determination. Second, because these induced feature sets form a hierarchy with increasing classification accuracy, video segments can be segmented and categorized simultaneously in a coarse-fine manner that efficiently and progressively detects and refines their temporal boundaries. Third, the feature set hierarchy enables an efficient implementation of query systems by the approach of lazy evaluation, in which new queries are used to refine the retrieval index in real-time. We analyze the performance of these methods, and demonstrate them in the domain of a 75-min instructional video and a 30-min baseball video.
Uses of information sources in an internet-era firm: online and offline
Authors: Anabel Quan-Haase, Joseph Cothrel
Venue: Communities and Technologies (2003)

Most research on the role of information and communication technologies (ICT) in the workplace has focused on companies that adopted ICT after many years of working without it. However, companies that have been "always connected" may offer different lessons. In this study, we look at how workers at an Internet-era company obtain information they need to do their jobs. We look at both human and documentary sources of information; whether those sources are accessed online or offline; and the impact of type of information source and access on individual performance. Results parallel past research with two significant differences: 1) workers accessed human sources via online channels more frequently than via offline channels, and 2) higher individual performance was associated with online access to human sources rather than offline access to human sources. The findings have implications for theories of knowledge management and uses and effects of technology in organizations.
On super-irreducible forms of linear differential systems with rational function coefficients
Authors: M. A. Barkatou
Venue: Journal of Computational and Applied Mathematics (2004)

Consider a system of n linear first-order differential equations (d/dx)y = A(x)y in which A(x) is an n × n matrix of rational functions over a subfield F of the field C of complex numbers and let Γ = {α1; .... ,αd} ⊆ C be a set of conjugate singularities of this system, i.e., poles of A(x) which are roots in C of some irreducible polynomial p(x) in F[x]. We propose an algorithm for transforming the given system into an equivalent system over F(x) which is super-irreducible in each element α ∈ Γ. This algorithm does not require working in the algebraic extension F(Γ) that appears when one applies Hilali-Wazner's algorithm (Numer. Math. 50 (1987) 429) successively with the individual singularities α1,...,αd. The transformation matrix as well as the resulting system have their coefficients in F(x) and all the computations are performed in F[x]/(p) instead of the splitting field of p.
The parametrized complexity of knot polynomials
Authors: J. A. Makowsky, J. P. Mariño
Venue: Journal of Computer and System Sciences (2003)

We study the parametrized complexity of the knot (and link) polynomials known as Jones polynomials, Kauffman polynomials and HOMFLY polynomials. It is known that computing these polynomials is #P hard in general. We look for parameters of the combinatorial presentation of knots and links which make the computation of these polynomials to be fixed parameter tractable, i.e., in the complexity class FPT. If the link is explicitly presented as a closed braid, the number of its strands is known to be such a parameter. In a generalization thereof, if the link is explicitly presented as a combination of compositions and rotations of k-tangles the link is called k-algebraic, and its algebraicity k is such a parameter. The previously known proofs that, for this parameter, the link polynomials are in FPT uses the so called skein modules, and is algebraic in its nature. Furthermore, it is not clear how to find such an algebraic presentation from a given link diagram. We look at the treewidth of two combinatorial presentation of links: the crossing diagram and its shading diagram, a signed graph. We show that the treewidth of these two presentations and the algebraicity of links are all linearly related to each other. Furthermore, we characterize the k-algebraic links using the pathwidth of the crossing diagram. Using this, we can apply algorithms for testing fixed treewidth to find k-algebraic presentations in polynomial time. From this we can conclude that also treewidth and pathwidth are parameters of link diagrams for which the knot polynomials are FPT. For the Kauffman and Jones polynomials (but not for the HOMFLY polynomials) we get also a different proof for FPT via the corresponding result for signed Tutte polynomials.
A bijection for triangulations of a polygon with interior points and multiple edges
Authors: Dominique Poulalhon, Gilles Schaeffer
Venue: Theoretical Computer Science (2003)

Loopless triangulations of a polygon with k vertices in k + 2n triangles (with interior points and possibly multiple edges) were enumerated by Mullin in 1965, using generating functions and calculations with the quadratic method.In this article we propose a simple bijective interpretation of Mullin's formula. The argument rests on the method of conjugacy classes of trees, a variation of the cycle lemma designed for planar maps. In the much easier case of loopless triangulations of the sphere (k = 3), we recover and prove correct an unpublished construction of the second author.
Variable Independence in Constraint Databases
Authors: Jan Chomicki, Dina Goldin, Gabriel Kuper, David Toman
Venue: IEEE Transactions on Knowledge and Data Engineering (2003)

In this paper, we study constraint databases with variable independence conditions (vics). Such databases occur naturally in the context of temporal and spatiotemporal database applications. Using computational geometry techniques, we show that variable independence is decidable for linear constraint databases. We also present a set of rules for inferring vics in relational algebra expressions. Using vics, we define a subset of relational algebra that is closed under restricted aggregation.
A graphical approach for reducing spreadsheet linking errors
Authors: Charles M. Morrison, Joline Morrison, John Melrose, E. Vance Wilson
Venue: Advanced topics in end user computing (2003)

Spreadsheet programs are deceptively simple tools that are widely used by end user developers in organizations. However, recent studies have shown that spreadsheets often contain significant, decision-affecting errors. One study that addressed "linking errors," i.e., incorrect references to spreadsheet cell values on separate work areas, found these errors to be a major error source in complex spreadsheets that use distinct work areas spread across multiple worksheets. This paper describes a code inspection approach that visually represents the structure of a linked spreadsheet and graphically identifies linked cells and their sources. We tested this approach in an experimental study where subjects created a complex spreadsheet. Results indicate that subjects who used the approach made significantly fewer errors and experienced no decrease in speed of spreadsheet production or satisfaction with the production process.
Traversing the Web: Mobility Heuristics for Visually Impaired Surfers
Authors: Simon Harper, Carole Goble, Robert Stevens
Venue: Proceedings of the Fourth International Conference on Web Information Systems Engineering (2003)

Movement, or mobility, is key to the accessibility, design, and usability of many websites. While some peripheral mobility issues have been addressed few have centered on the mobility problems of visually impaired users. We use our past work to address these issues and derive mobility heuristics from mobility models, use these heuristics to place mobility objects within a web page, and describe the construction of a prototype mobility instrument, in the form of a Netscape plug-in, to process these objects. Our past work extends the notion of movement to include environment, feedback and the purpose of the current travel task. Specifically, we likened web use to travelling in a virtual space, compared it to travelling in a physical space,and introduced the idea of mobility - the ease of travel - as opposed to travel opportunity.
Self-Similarity Bounds for Locally Thin Set Families
Authors: Emanuela Fachini, János Körner, Angelo Monti
Venue: Combinatorics, Probability and Computing (2001)

A family of subsets of an n-set is k-locally thin if, for every k-tuple of its members, the ground set has at least one element contained in exactly one of them. For k = 5 we derive a new exponential upper bound for the maximum size of these families. This implies the same bound for all odd values of k > 3. Our proof uses the graph entropy bounding technique to exploit a self-similarity in the structure of the hypergraph associated with such set families.
Simple blurry reflections with environment maps
Authors: Michael Ashikhmin, Abhijeet Ghosh
Venue: Journal of Graphics Tools (2002)

We present a technique which uses existing OpenGL capabilities to approximate the effect of blurry specular reflections and indirect diffuse illumination. It makes use of environment maps, mipmapping with level of detail control, and possibly texture borders. The method is extremely simple to implement, in some cases requiring just a single additional OpenGL statement.
Performance Issues of Bandwidth Reservations for Grid Computing
Authors: Lars-Olof Burchard, Hans-Ulrich Heiss, César A. F. De Rose
Venue: Proceedings of the 15th Symposium on Computer Architecture and High Performance Computing (2003)

In general, two types of resource reservations in computer networks can be distinguished: immediate reservations which are made in a just-in-time manner and advance reservations which allow to reserve resources a long time before they are actually used. Advance reservations are especially useful for grid computing but also for a variety of other applications that require network quality-ofservice, such as content distribution networks or even mobileclients, which need advance reservation to support handovers for streaming video. With the emerged MPLS standard, explicit routing can be implemented also in IP networks, thus overcoming the unpredictable routing behavior which so far prevented the implementation of advance reservation services. The impact of such advance reservation mechanisms on the performance of the network with respect to the amount of admitted requests and the allocatedbandwidth has so far not been examined in detail. In this paper, we show that advance reservations can lead to a reduced performance of the network with respect to both metrics. The analysis of the reasons shows a fragmentation of the network resources. In advance reservation environments, additional new services can be de.ned such as malleable reservations which are introduced in this paper and can lead to an increased performance of the network. Four strategies for scheduling malleable reservations are presented and compared. The results of the comparisons show that some strategies increase the resource fragmentation and are therefore unsuitable in the considered environment while others lead to a significantly better performance of the network. Besides discussing the performance issue, in this paper the software architecture of a management system for advance reservations is presented.
The Poisson&ndash;Dirichlet Distribution and the Scale-Invariant Poisson Process
Authors: Richard Arratia, A. D. Barbour, Simon Tavaré
Venue: Combinatorics, Probability and Computing (1999)

We show that the Poisson&ndash;Dirichlet distribution is the distribution of points in a scale-invariant Poisson process, conditioned on the event that the sum T of the locations of the points in (0,1] is 1. This extends to a similar result, rescaling the locations by T, and conditioning on the event that T&le;1. Restricting both processes to (0, &beta;] for 0<&beta;&le;1, we give an explicit formula for the total variation distance between their distributions. Connections between various representations of the Poisson&ndash;Dirichlet process are discussed.
ICA for watermarking digital images
Authors: Stéphane Bounkong, Borémi Toch, David Saad, David Lowe
Venue: The Journal of Machine Learning Research (2003)

We present a domain-independent ICA-based approach to watermarking. This approach can be used on images, music or video to embed either a robust or fragile watermark.In the case of robust watermarking, the method shows high information rate and robustness against malicious and non-malicious attacks, while keeping a low induced distortion. The fragile watermarking scheme, on the other hand, shows high sensitivity to tampering attempts while keeping the requirement for high information rate and low distortion. The improved performance is achieved by employing a set of statistically independent sources (the independent components) as the feature space and principled statistical decoding methods. The performance of the suggested method is compared to other state of the art approaches. The paper focuses on applying the method to digitized images although the same approach can be used for other media, such as music or video.
Efficient decomposition of separable algebras
Authors: W. Eberly, M. Giesbrecht
Venue: Journal of Symbolic Computation (2004)

We present new, efficient algorithms for computations on separable matrix algebras over infinite fields. We provide a probabilistic method of the Monte Carlo type to find a generator for the center of a given algebra 2l ⊆ Fm × m over an infinite field F. The number of operations used is within a logarithmic factor of the cost of solving m × m systems of linear equations. A Las Vegas algorithm is also provided under the assumption that a basis and set of generators for the given algebra are available. These new techniques yield a partial factorization of the minimal polynomial of the generator that is computed, which may reduce the cost of computing simple components of the algebra in some cases.
A multi-phase constructive heuristic for the vehicle routing problem with multiple trips
Authors: R. J. Petch, S. Salhi
Venue: Discrete Applied Mathematics (2003)

An extension to the classical vehicle routing problem where vehicles can be assigned more than one route within a working time period is investigated. A multi-phase constructive heuristic, which is enhanced by suitable data structure, is proposed. Results are given comparing to benchmarks from the literature.
Making patterns explicit with metaprogramming
Authors: Daniel von Dincklage
Venue: Proceedings of the 2nd international conference on Generative programming and component engineering (2003)

Design patterns have been a useful tool for a better understanding of the collaboration between several classes and objects in a program.One drawback of this approach is the lack of an explicit representation of the patterns used in a program, as the collaboration between classes is normally expressed in the code of the class itself.In this paper, we present a method for explicitly representing patterns in a program with the help of metaprogramming techniques. The method presented has benefits compared to traditional approaches with respect to documentation and reusability of the program, as well as providing a better separation of the protocol contained in the pattern.
Cyclic Economic Processes in Systems with Monopsonic Labor Markets
Authors: Ye. P. Belan, M. V. Mikhalevich, I. V. Sergienko
Venue: Cybernetics and Systems Analysis (2003)

A dynamical macromodel of an economic system with a competitive commodity market and a monopsonic labor market is considered. For this model, conditions of the onset of economic cycles that are similar to classical business cycles are investigated. Mechanisms of formation of such cycles as a result of interaction between the commodity market and the labor market are analyzed.
Correlation Analysis of the Alternating Step Generator
Authors: Jovan D. J. Golić, Renato Menicocci
Venue: Designs, Codes and Cryptography (2004)

The alternating step generator is a well-known keystream generator consisting of two stop/go clocked LFSRs, LFSR1 and LFSR2, whose clocks are controlled by another LFSR, LFSR3, which is clocked regularly. A probabilistic analysis of this generator is conducted which shows that the posterior probabilites of individual bits of the first derivatives of the regularly clocked LFSR1 and LFSR2 sequences, when conditioned on a given segment of the first derivative of the keystream sequence, can be computed efficiently in a number of probabilistic models of interest. The expected values of these probabilities, for a random keystream sequence, are derived by an approximate theoretical analysis and are also verified by systematic computer experiments. It is pointed out that these posterior probabilities can be enhanced in a resynchronization scenario and thus used for a low-complexity fast correlation attack on the two LFSRs. More generally, it is argued that even without resynchronization these probabilities may be significantly different from one half for fast correlation attacks based on iterative decoding algorithms to be successful, although with incresead complexity. A related method for computing the posterior probabilities of individual bits of the LFSR3 sequence, when conditioned on both the keystream sequence and the LFSR1 and LFSR2 sequences, is also developed. As these posterior probabilities are much more different from one half, they can be used for a low-complexity fast correlation attack on LFSR3, provided that the initial states of LFSR1 and LFSR2 are previously reconstructed.
Implicit user profiling for on demand relevance feedback
Authors: Yoshinori Hijikata
Venue: Proceedings of the 9th international conference on Intelligent user interfaces (2004)

In the area of information retrieval and information filtering, relevance feedback is a popular technique which searches similar documents based on the documents browsed by the user. If the user wants to conduct relevance feedback on demand, which means the user wants to see similar documents while reading a document, the existing user profiling techniques cannot acquire keywords in high precision that the user is interested in at such a short time. This paper proposes a method for extracting text parts which the user might be interested in from the whole text of the Web page based on the user's mouse operation in the Web browser. The objective of this research is to (1) find what kind of mouse operation represent users' interests, (2) see the effectiveness of the found mouse operation in selecting keywords, and (3) compare our method with tf-idf, which is the most fundamental method used in many user profiling systems. From the user experiment, the precision to select keywords of our method is about 1.4 times compared with that of tf-idf.
Frequent loop detection using efficient non-intrusive on-chip hardware
Authors: Ann Gordon-Ross, Frank Vahid
Venue: Proceedings of the 2003 international conference on Compilers, architecture and synthesis for embedded systems (2003)

Dynamic software optimization methods are becoming increasingly popular for improving software performance and power. The first step in dynamic optimization consists of detecting frequently executed code, or "critical regions." Previous critical region detectors have been targeted to desktop processors. We introduce a critical region detector targeted to embedded processors, with the unique features of being very size and power efficient, and being completely non-intrusive to the software's execution - features needed in timing-sensitive embedded systems. Our detector not only finds the critical regions, but also determines their relative frequencies, a potentially important feature for selecting among alternative dynamic optimization methods. Our detector uses a tiny cache coupled with a small amount of logic. We provide results of extensive explorations across seventeen embedded system benchmarks. We show that highly accurate results can be achieved with only a 0.02% power overhead and acceptable size overhead. Our detector is currently being used as part of a dynamic hardware/software partitioning approach, but is applicable to a wide-variety of situations.
Open nested serializability in multidatabase systems
Authors: Dexter P. Bradshaw
Venue: Proceedings of the 1992 conference of the Centre for Advanced Studies on Collaborative research - Volume 2 (1992)

Most previous work on transaction management in multidatabase systems assumes a two-level architecture consisting of a multidatabase and a set of simple participant database management systems. In this paper we relax this assumption and allow for the arbitrary hierarchical composition of other multidatabase systems as participants. We refer to this architecture as an open nested architecture and develop a correctness criterion for transactions that run concurrently in this environment.Our correctness criterion generalizes both hierarchical serializability and multidatabase serializability because no restrictions are imposed on the depth of nesting of subtransactions across a hierarchically composed set of multidatabases. Given that each multidatabase is autonomous, we show that previous correctness criteria can be applied recursively to each multidatabase, provided that a particular ordering properties of subtransactions and their underlying actions are maintained at each level of a multilevel transaction.
Concepts for usable patterns of groupware applications
Authors: Thomas Herrmann, Marcel Hoffmann, Isa Jahnke, Andrea Kienle, Gabriele Kunau, Kai-Uwe Loser, Natalja Menold
Venue: Proceedings of the 2003 international ACM SIGGROUP conference on Supporting group work (2003)

Patterns, which are based on in-depth practical experience, can be instructing for the design of groupware applications as socio-technical systems. On the basis of a summary of the concept of patterns - as elaborated by the architect Christopher Alexander - its adoptions within computer science are retraced and relationships to the area of groupware are described. General principles for patterns within this domain are formulated and supported by examples from a wide range of experience with knowledge management systems. The analysis reveals that every pattern of a groupware application has to combine the description of social as well as technical structures, and that a single pattern can only be understood in the context of a pattern language. It also shows that such a language has to integrate patterns of socio-technical solutions with measures and procedures for introducing them, and that the language not only has to express one type of directed relationship between the patterns but a variety of different types which have to be deliberately assigned to the patterns.