ppxscal/embedding_network huggingface dataset:
Randomized Reductions and Isomorphisms
Authors: Jie Wang
Venue:  (1999)

Randomizing reductions have provided new techniques for tackling average-case complexity problems. For example, although some NP-complete problems with uniform distributions on instances cannot be complete under deterministic one-one reductions [Wang and Belanger], they are complete under randomized reductions [Venkatesan and Levin]. We study randomized reductions in this paper on reductions that are one-one and honest mappings over certain input domains. These are reasonable assumptions since all the randomized reductions in the literature that are used in proving average-case completeness results possess this property. We consider whether randomized reductions can be inverted efficiently. This gives rise to the issue of randomized isomorphisms. By generalizing the notion of isomorphisms under deterministic reductions, we define what it means for two distributional problems to be isomorphic under randomized reductions. We then show a randomized version of the Cantor-Bernstein-Myhill theorem, which provides a sufficient condition for two distributional problems to be isomorphic under randomized reductions. Based on that condition we show that all the known average-case NP-complete problems (including those that are complete under deterministic reductions) are indeed isomorphic to each other under randomized reductions. 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
Compiling Object-Oriented Queries
Authors: Theodore W. Leung
Venue:  (1994)

The effectiveness of database query optimization is dependent on the optimizer''s ability to make efficient use of physical resources in a computer system. The optimizer decides how to use those resources in the plan generation step. We describe an approach to plan generation where physical level rewriting produces performance increases which cannot be obtained via source level transformations. Example optimizations serve as a demonstration of a new rule language based on list and tree pattern matching. A formalism similar to attribute grammars computes information needed by the plan generator. Many of the techniques presented are reminiscent of compiler optimizations. We conclude by describing the work that will be completed in the thesis.
Botanical Visualization of Huge Hierarchies
Authors: Ernst Kleiberg, Huub van de Wetering, Jarke J. Van Wijk
Venue: Proceedings of the IEEE Symposium on Information Visualization 2001 (INFOVIS'01) (2001)

A new method for the visualization of huge hierarchical data structures is presented. The method is based on the observation that we can easily see the branches, leaves and their arrangement in a botanical tree, despite of the large number of elements. The strand model of Holton is used to convert an abstract tree into a geometric model. Non-leaf nodes are mapped to branches and child nodes to sub-branches. A naive application of this model leads to unsatisfactory results, hence it is tailored to suit our purposes better. Continuing branches are emphasized, long branches are contracted, and sets of leaves are shown as fruit. The method is applied to the visualization of directory structures. The elements, directories and files, as well as their relations can easily be extracted, thereby showing that the use of methods from botanical modeling can be effective for information visualization.
Binary space partitioning trees: a multiresolution approach
Authors: J. Huerta, M. Chover, R. Quiros, R. Vivo, J. Ribelles
Venue: Proceedings of the IEEE Conference on Information Visualisation (1997)

Space partitioning techniques are a useful means of organizing geometric models into data structures. Such data structures provide easy and efficient access to a wide range of computer graphics and visualization applications like real time rendering of large databases, collision detection, point classification, etc. Binary space partitioning (BSP) trees are one of the most successful space partitioning techniques, since they allow both object modeling and classification in one single structure. However, with the advent of networked graphics applications, there is an increasing need for multiresolution geometric representations. The paper presents a novel method that extends BSP trees to provide such a representation. The models we present have the advantages of both BSP trees and multiresolution representations. Nodes near the root of the BSP tree store coarser versions of the geometry, while leaf nodes provide the finest details of the representation. We present different algorithms to construct multiresolution BSP trees in 2D. Then we propose extensions of our methods to 3D space.
Learning New Words from Spontaneous Speech: A Project Summary
Authors: Sheryl R. Young
Venue:  (1993)

This research develops methods that enable spoken language systems to detect and correct their own errors, automatically extending themselves to incorporate new words. The occurrence of unknown or out-of-vocabulary words is one of the major problems frustrating the use of automatic speech understanding systems in real world tasks. Novel words cause recognition errors and often result in recognition and understanding failures. Yet, they are common. Real system users speak in a spontaneous and relatively unconstrained fashion. They do not want words the system can recognize and thereby are likely to exceed the system''s coverage. Even if speakers constrained their speech, there would still be a need for self-extending systems as certain tasks inherently require dynamic vocabulary expansion (e.g. new company names, new flight destinations, etc.). Further, it is costly and labor intensive to collect enough training data to develop a representative vocabulary (lexicon) and language model for a spoken interface application. Unlike transcription tasks where it is often possible to find large amounts of on-line data from which a lexicon and language model can be developed, for many tasks this is not feasible. Developers of applications and database interfaces will probably not have the resources to gather a large corpus of examples to train a system to their specific task. Yet, most current speech and language model research is oriented toward training from large corpora. This research enables systems to be developed from small amounts of data and then "bootstrapped. A simple version of a system is initially created using only a small set of examples. Its coverage is then automatically extended as the system encounters new input through interaction with users. The system learns new words from spontaneous speech and incrementally augments its grammar and lexicon. There are two important aspects of our approach: Conjoined use of many knowledge sources to detect recognition errors and determine whether an out-of-vocabulary word is present. The system uses its higher-level knowledge sources to determine the meaning of new words to determine how to add the new words to the system grammar, language models and lexicon. 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 Aggregation Technique for the Transient Analysis of Stiff Markov Chains
Authors: Andrea Bobbio, S K Trivedi
Venue:  (1984)

An approximation algorithm for systematically converting a stiff Markov chain into a non-stiff chain with a smaller state space is discussed in this paper. After classifying the set of all states into fast and slow states, the algorithm proceeds by further classifying fast states into fast recurrent subsets and a fast transient subset. A separate analysis of each of these fast subsets is done and each fast recurrent subset is replaced by a single slow state while the fast transient subset is replaced by a probabilistic switch. After this reduction, the remaining small and non-stiff Markov chain is analyzed by a conventional technique. The algorithm produces asymptotically exact results with respect to the aggregation of fast transient states, while for fast recurrent subsets the asymptotic accuracy depends on the degree of coupling between the fast subset and the remaining states. The algorithm is illustrated using two examples.
Cost distributions in symmetric euclidean traveling salesman problems -- a supplement to TSPLIB
Authors: Florian Waas
Venue:  (1999)

We present analytically and experimentally determined cost distributions for all euclidean two-dimensional symmetric instances of the Traveling Salesman Problem in the TSPLIB library. Results obtained show characteristic cost distributions in all cases with and a high stability against degeneration.
A Counter-example for ``A Simpler Construction for Showing the IntrinsicallyExponential Complexity of the Circularity Problem for Attribute Grammars''''
Authors: Jens M. Dill
Venue:  (1987)

Jazayeri proposes a simpler construction for use in the proof by Jazayeri, Ogden, and Rounds that the circularity problem for attribute grammars has inherent exponential complexity. The simplification introduces a flaw that invalidates the proof. Correcting the flaw leaves the new construction only slightly simpler than the old.
Data Distribution and Communication Schemes for IQMR Method on Massively Distributed Memory Computers
Authors: Laurence Tianruo Yang
Venue: Proceedings of the 2000 International Workshop on Parallel Processing (2000)

In this paper, we study the parallelization of IQMR method for the solutions of linear systems of equations with unsymmetric coefficient matrices. The IQMR method is an improved version of the quasi-minimal residual (IQMR) method by using the Lanczos process as a major component combining elements of numerical stability and parallel algorithm design. The algorithm is derived such that all inner products and matrix-vector multiplications of a single iteration step are independent and communication time required for inner product can be overlapped efficiently with computation time. Two important schemes are discussed. What is the best possible data distribution and which communication network topology is most suitable for IQMR method on massively parallel-distributed memory computers. A theoretical model of data distribution and communication phases is presented mainly based on [14, 15] which allows us to give a detail execution time complexity analysis and investigates its usefulness. It is shown that the implementation of IQMR, with a row-block decomposition of the coefficient matrix, on a ring of communication structure is the most efficient choice. Performance tests of the developed parallel IQMR algorithm have been carried out on the massively distributed memory system and experimental timing results are compared with the theoretical execution time complexity analysis. 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
Adaptive Transmission Parameters Optimization in Wireless Multi-Access Communication
Authors: Fraser Cameron, Moshe Zukerman, Maxim Gitlits
Venue: Proceedings of the 7th IEEE International Conference on Networks (1999)

The purpose of this paper is to optimize a wireless link which uses Forward Error Correction (FEC), Modulation Gain, and for data services, Automatic Repeat Request (ARQ) protocols, with the aim to minimize the bandwidth required. Simulations are used to derive Bit Error Rate values for a range of modulation and FEC Code Rate parameters. These parameters are optimized to maximize efficiency. We demonstrate that optimal adaptive modulation provides significant efficiency gains. We actually question the use of FEC for a wide (practical) range of Signal to Noise ratios, and demonstrate that in the case of data traffic, optimal adaptive modulation together with ARQ retransmission, in the absence of FEC, provides better efficiency, and/or QoS, than the same system with FEC. Similar results are achieved also for video, where ARQ is not used.
Building a programmable multiplexing service using concast
Authors: K. L. Calvert, J. Griffioen, A. Sehgal, Su Wen
Venue: Proceedings of the 2000 International Conference on Network Protocols (2000)

Concast is a scalable "inverse-multicast" network service: messages sent from multiple sources toward the same destination are merged into a single message that is delivered to the destination. The mapping from sent messages to received messages is programmable, so the service can be tailored to the needs of specific applications. However the service can also be used as a building block for other generic network services, such as a packet multiplexing service that encapsulates multiple small packets into a single larger packet and then unencapsulates the small packets at their (common) destination. Such a service offers several potential benefits, including reduced packet processing overhead and increased rate-sharing, but must also be carefully designed to avoid problems caused by added packet delays. We show how concast can serve as the basis for a multiplexing service that can be tailored to the needs of the application. We present simulation results showing that the benefits of our multiplexing service vary with delay. We also show that given certain queue-manipulation capabilities, benefits can be achieved with zero added delay.
A Reconfigurable Low-Power High-Performance Matrix Multiplier Design
Authors: Rong Lin
Venue: Proceedings of the 1st International Symposium on Quality of Electronic Design (2000)

A novel reconfiguable low-power high-performance matrix multiplier architecture and its component circuits are presented. The processor can be easily reconfigured to compute the product of matrices Xnk and Ykm for any integers n, k, m and any item precision b (ranging from 4 to 64 bits) thus maximizing the utilization of the hardware available.As a typical example, the hardware equivalent to one 64 x 64 bit high precision multiplier in the system can be directly reconfigured to produce the product of two matrices X(8x8) and Y(8x8) of 8-bit items in 9 pipeline cycles, which would require 512 multiplications (done by large multipliers) in a non-reconfigurable high precision system.Given an input stream of h x h matrix pairs with b-bit items, the processor, called matrix multiplier of size s (note s=hb), may consist of an array of (s / m)2 of m x m small multipliers (m=4 case is illustrated), a few arrays of adders each adding three numbers, an array of accumulators and corresponding simple reconfiguration switches. To compute the product of Xnk and Ykm of item precision b on the proposed processor of size s we only need to partition Xnk and Ykm into (s/b) x (s/b) sub-matrices, reconfigure the processor according to the values of s (fixed) and b (input parameter), compute the products of sub-matrices, and accumulate them for the desired result in pipelined fashion.A recently proposed shift switch logic, a non-binary logic for arithmetic circuits, is utilized in the design. The novel logic operates 4-bit state signals where no more than half of the signal bits are subject to value-change at any logic stage, which, verified by SPICE simulation, significantly reduces the large circuit power dissipation while keeping high performance in speed and small VLSI area.
VoiceXML 2.0 Developer's Guide
Venue:  (2002)

:Engineer your way to excellence! This professional resource explains in full detail how to build VoiceXML-based applications using real-world programs you can adapt for your own projects. The book includes three full-scale, enterprise-level applications complete with all source code. 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
Selection of information types based on personal utility: a testbed for traffic information markets
Authors: Franziska Klügl, Ana L. C. Bazzan, Joachim Wahle
Venue: Proceedings of the second international joint conference on Autonomous agents and multiagent systems (2003)

Traffic is an interesting research area for multi-agent systems, as the inter-dependence of actions leads to a high frequency of implicit coordination decisions among agents. The present work investigates the simulation of a market for traffic information. This market is implemented as a traffic centre where some measurements of the traffic conditions are evaluated. Simulated data generates information which is "sold" to drivers. Different levels of data aggregation, at different costs, are available. We simulate drivers buying this information and evaluating their utility. Based on their perception of this worthiness they will continue with their strategy of buying (or not) particular forms of information, or will abandon or change such a strategy. Our results are twofold. First, they corroborate previous studies from traffic engineers and traffic economists which i) question the presumption that information is necessarily beneficial for traffic as a whole, and ii) state that drivers who rely only on conventional information are likely to have an inaccurate knowledge of traffic conditions. Second, we show that not all types of simple information bring the same payoff to the informed drivers.
GeoTORA: a protocol for geocasting in mobile ad hoc networks
Authors: Young-Bae Ko, N. H. Vaidya
Venue: Proceedings of the 2000 International Conference on Network Protocols (2000)

This paper considers the problem of providing a geocast service in mobile ad hoc networks and presents a novel geocasting algorithm combining unicasting and flooding. Geocast is useful for sending messages to everyone in a specified geographical region. The proposed protocol is named GeoTORA, because it is derived from the TORA (unicast) routing protocol. Flooding is also incorporated in GeoTORA, but it is limited to nodes within a small region. This integration of TORA and flooding can significantly reduce the overhead of geocast delivery while maintaining reasonably high accuracy.
Two-dimensional substring indexing
Authors: Paolo Ferragina, Nick Koudas, S. Muthukrishnan, Divesh Srivastava
Venue: Journal of Computer and System Sciences (2003)

As databases have expanded in scope to storing string data (XML documents, product catalogs), it has become increasingly important to search databases based on matching substrings, often on multiple, correlated dimensions. While string B-trees are I/O optimal in one dimension, no index structure with non-trivial query bounds is known for two-dimensional substring indexing. In this paper, we present a technique for two-dimensional substring indexing based on a reduction to the geometric problem of identifying common colors in two ranges containing colored points. We develop an I/O efficient algorithm for solving the common colors problem, and use it to obtain an I/O efficient (poly-logarithmic query time) algorithm for the two-dimensional substring indexing problem. Our techniques result in a family of secondary memory index structures that trade space for time, with no loss of accuracy.
Fast Texture Transfer
Authors: Michael Ashikhmin
Venue: IEEE Computer Graphics and Applications (2003)

A simple technique for fast texture transfer between images can produce quality results similar to current state of the art methods but at a fraction of the cost. The article demonstrates several application of the method including artistic style transfer, image enhancement, and novel nonphotorealistic filter creation.
A Replication Protocol to Support Dynamically Configurable Groups of Servers
Authors: Christos T. Karamanolis, Jeff N. Magee
Venue: Proceedings of the 3rd International Conference on Configurable Distributed Systems (1996)

The paper addresses the problem of dynamic configuration management of highly available services. In particular, we are concerned with services that are provided by a group of actively replicated servers and are used by a large, rapidly changing set of clients. In this system model, we propose a Replication Management Protocol to facilitate the dynamic configuration management of the server group, while maintaining service state consistency. We argue about the correctness of the protocol and report on initial implementation results.
Logical not Polynomial Forms to represent Multiple-Valued Functions
Authors: Elena N. Zaitseva, Tatyana G. Kalganova, Evgeny G. Kochergov
Venue: Proceedings of the 26th International Symposium on Multiple-Valued Logic (1996)

The synthesis of logical not polynomial forms to represent completely and incompletely defined multiple-valued logic functions is proposed. To compute these forms, discrete orthogonal transforms are used. The matrix and vector procedures are the founda
Two Papers on the Linearity of Finite Automata
Authors: Bernd Reusch
Venue:  (1976)

NO SUPPLIED
Matrix Approximation Problems and Nonsymmetric Iterative Methods
Authors: Kim C Toh
Venue:  (1996)

The following contains mathematical formulae and symbols that may become distorted in ASCII text format. The GMRES algorithm, which solves systems of equations Ax = b, constructs the nth iterate as the solution to the vector approximation problem min (sub p) ||p(A)b|| =:||p(sub b)(A)b||, for polynomials p of degree n normalized at z=0. The ideal GMRES problem is obtained if one considers the matrix approximation problem min (sub p) ||p(A)|| =:||p*(sub n)(A)|| instead. The Arnoldi and ideal Arnoldi problems are the analogs of the GMRES and ideal GMRES problems, except that the minimizations are over monic polynomials of degree n. In the usual convergence analysis of Krylov subspace methods, the vector approximation problems actually solved by the iterations (exactly or approximately) are replaced by the conceptually simpler ideal problems, which are in turn analyzed in terms of scalar approximation problems on the complex plane. This thesis explores certain connections between the GMRES and Arnoldi iterations and various approximation problems.
Arc Diagrams: Visualizing Structure in Strings
Authors: Martin Wattenberg
Venue: Proceedings of the IEEE Symposium on Information Visualization (InfoVis'02) (2002)

This paper introduces a new visualization method, the arc diagram, which is capable of representing complex patterns of repetition in string data. Arc diagrams improve over previous methods such as dotplots because they scale efficiently for strings that contain many instances of the same subsequence. This paper describes design and implementation issues related to arc diagrams and shows how they may be applied to visualize such diverse data as music, text, and compiled code.
A generalized storage model for tertiary storage based systems
Authors: R. V. Tikekar, F. Fotouhi, D. Ragan
Venue: Proceedings of the 1997 International Symposium on Database Engineering & Applications (1997)

Most of the research in the area of database query optimization has dealt with data that is either in main memory or on disk. Lately there has been growing interest in making tertiary memory part of an information system. The authors propose a model for a generic storage system and generic data placement techniques. Such a model provides one with a tool to study query performance and optimization techniques in tertiary device based systems by varying the different storage system, data placement, and system configuration parameters. They then demonstrate one use of the model by using it in a tertiary storage system setup to measure the cost of relational join algorithms.