ppxscal/embedding_network huggingface dataset:
Computing the Singular Value Decomposition on a Distributed System of Vector Processors
Authors: Christian H. Bischof
Venue:  (1987)

Jacobi methods for computing the singular value decomposition (SVD) of a matrix are ideally suited for multiprocessor environments due to their inherent parallelism. In this paper we show how a block version of the two-sided Jacobi method can be used to compute the SVD efficiently on a distributed architecture. We compare two variants of this method that differ mainly in the degree to which they diagonalize a given subproblem. The first method is a true block generalization of the scalar scheme in that each off-diagonal block is completely annihilated. The second method is a scalar Jacobi algorithm reorganized in such a manner that it conforms to the block decomposition of the problem. We have performed experiments on the Loosely Coupled Array Processor (LCAP) system at IBM Kingston which for the purposes of this article can be viewed as a ring of up to ten FPS-164/MAX array processors. These experiments show that the block Jacobi algorithm performs well on a distributed system, especially when the processors have vector processing hardware. As an example, we were able to achieve a sustained performance of 159 MFlops on a 960-by-720 SVD problem using eight processors. A surprising outcome of these experiments is that the determining factor for the performance of the algorithm on a high-performance architecture is the subproblem solver, not the communication overhead of the algorithm.
X python reference manual
Authors: K. S Mullender
Venue:  (1995)

This document describes the built-in types, exceptions, and functions of the X windows extension to Python. It assumes basic knowledge about the Python language and access to the X windows documentation. For an informal introduction to the language, see the Python Tutorial. The Python Reference Manual gives a more formal definition of the language. The Python Library Reference describes the built-in and standard modules of Python. This document can be seen as en extension to that document.
The Price of Anarchy with Polynomial Edge Latency
Authors: Tim Roughgarden
Venue:  (2001)

We consider the problem of routing traffic to optimize the performance of a congested network. We are given a network, a rate of traffic between each pair of nodes, and a latency function for each edge specifying the time needed to traverse the edge given its congestion; the objective is to route traffic such that the sum of all travel times---the total latency---is minimized. In many settings, it is not possible to implement an optimal assignment of routes. In the absence of regulation by some central authority, we assume that each network user routes its traffic on the minimum-latency path available to it, given the network congestion caused by the other users. In general such a ``selfishly motivated'''' assignment of traffic to paths will not minimize the total latency; hence, this lack of regulation carries the cost of decreased network performance. In this paper, we prove that if the latency of each edge is a polynomial function of degree at most $p$ of the edge congestion, then the total latency of the routes chosen by selfish network users is at most $[1 p \cdot (p+1)^{-(p+1)/p}]^{-1} = \Theta(\frac{p}{\ln p})$ times the minimum possible total latency. A simple example shows that this result is best possible for all values of $p$.
Semantics of Digital Networks Containing Indeterminate Modules
Authors: Robert M. Keller, Prakash Panangaden
Venue:  (1985)

We discuss a formal model based upon dataflow, usable for high-level digital hardware design, among other things. One of our goals is to give a denotational semantics for this model, which includes indeterminate modules. While it is well known that denotational semantics for networks containing only determinate modules can be simply expressed as a composition of stream functions, this aproach has previously been shown unacceptable for networks with indeterminate modules. Our approach is to devise composition rules based on modelling a network by the set of its possible behaviors, i.e., sequences of computational events, where each event is the appearance or consumption of a token on a data path. A sequence of such events is called a history and a set of such histories is called an archive. We give composition rules that allow us to derive an archive for a network from the archive of its constituents. We show how causal and operational constraints on network behavior can be inferred from the specification of archives. We also present a construction which allows us to obtain the the denotation of networks containing loops by a process of successive approximations. This construction is carried out using a construction resembling the category-theoretic notion of limit, which differs from that of more traditional domain theory.
Knowledge Source Network Configuration Approach to Knowledge Logistics
Authors: Alexander Smirnov, Mikhail Pashkin, Nikolai Chilov, Tatiana Levashova
Venue: Proceedings of the 2002 IEEE International Conference on Artificial Intelligence Systems (ICAIS'02) (2002)

Today an intensive knowledge exchange between participants of the global information environment is required. Along with a large number of distributed knowledge sources representing knowledge in various formats this leads to appearance of a new direction in knowledge management called knowledge logistics. The paper describes Knowledge SourceNetwork configuration approach (KSNet-approach) to knowledge logistics through knowledge fusion. It is based on such technologies as ontology management and intelligent agents. Themost important ideas of the proposed KSNet-approach were implemented and verified via developed software prototype of the system "KSNet".
Automatic Partitioning and Virtual Scheduling for Efficient Parallel Execution
Authors: Carolyn L. McCreary, D. H. Gill
Venue:  (1991)

The graph decomposition and scheduling method presented in this paper is a heuristic scheme for automatically converting a serial computation into a form suitable for processing on a multiprocessor system. Given a data flow graph of the serial algorithm, it identifies the parallelism in the graph, partitions the graph into grains of suitable size for a given underlying homogenous multiprocessor architecture and defines threads for scheduling the tasks on the processors. The objective function for the conversion is to find the shortest completion time for the computation on a given arbitrary architecture. The technique is based on defining a structure, the clan, that has properties desirable of a grain. A clan is a group of nodes whose sources and sinks are identical in their communication requirements with the rest of the graph, and no internal clan nodes communicate with nodes outside the clan. Clans can be classified as groups of computations that must be executed sequentially or as groups that may be executed in parallel. The data flow graph is parsed into a tree of clans where clans closest to the root are largest and leaves are singleton clans. A metric describing the performance characteristics of a given architecture is applied to the tree nodes, and evaluations are made to determine whether to aggregate or parallelize nodes that can be executed in parallel. Once the partitions have been determined, the graph nodes are grouped into computational threads where each thread it to be activated on a single processor. The threads can then be mapped onto processors. The graph decomposition and scheduling method can be applied to a wide variety of parallel architectures. The technique permits different partitions and different schedules to be discovered for different architectures. Communication overhead as well as execution costs are considered in determining partitions that yield an early completion time for the computation.
Balancing Web Server Load for Adaptable Video Distribution
Authors: Arindam Paul, Wu-chi Feng, D. K. Panda, P. Sadayappan
Venue: Proceedings of the 2000 International Workshop on Parallel Processing (2000)

As Web infrastructures continue to develop, the need to have network sensitive web servers will continue become more important. In particular, current network routers do not bias against flows that use more than their fair share of bandwidth. In the future, however, this will not be true, requiring the web servers to be network sensitive. In this paper, we investigate techniques for balancing web server load in servers that support network-sensitive video delivery. The goal of this research is to provide a scalable infrastructure that is well balanced in response times. Our results show that we can improve current DNS schemes for web server balancing significantly.
A signal-recovery system: asymptotic properties, and construction of an infinite-volume limit
Authors: J. Berg, B. Toth
Venue:  (2000)

We consider a linear sequence of `nodes'', each of which can be in state $0$ (`off'') or $1$ (`on''). Signals from outside are sent to the rightmost node and travel instantaneously as far as possible to the left along nodes which are `on''. These nodes are immediately switched off, and become on again after a recovery time. The recovery times are independent exponentially distributed random variables. We present properties for finite systems and use some of these properties to construct an infinite-volume extension, with signals `coming from infinity''. This construction is related to a question by D. Aldous and we expect that it sheds some light on, and stimulates further investigation of, that question.
Dynamic Memory Model Based Framework for Optimization of IP Address Lookup Algorithms
Authors: Gene Cheung, Steven McCanne
Venue: Proceedings of the Seventh Annual International Conference on Network Protocols (1999)

The design of software-based algorithms for fast IP address lookup targeted for general purpose processors has received tremendous attention in recent years due to its low cost implementation and flexibility. However, all work to date fails to account for the hierarchical memory structure of the processor when designing algorithms. In this work, we propose a dynamic memory model that captures data movement between hierarchical memories and the memory access cost.Using the model, we formulate the design of IP address lookup algorithms as a well-defined optimization problem that minimizes an algorithm's average lookup time. We first show the problem is NP-hard. We then present an optimization framework and associated algorithm based on Lagrange multipliers that terminates in a bounded-error solution. Simulation shows the synthesized algorithm has noticeable performance gain over existing techniques.
Jordan''s Lemma and its application for the analytical solution of integrals
Authors: D. Mugnai, A. Ranfagni, L. Ronchi
Venue:  (2000)

In physics, many integrals of practical interest do not have standard solutions and, in these cases, numerical solutions have to be found. However, it is often useful to know, where possible, also the analytical solution. To this end, we illustrate here how to apply Jordan''s Lemma in order to obtain exact analytical solutions. For example, this technique will be applied to two integrals describing the electromagnetic propagation through an air gap in the case of frustrated total reflection, for two different incident pulses. EMAIL:: mugnai@iroe.fi.cnr.it
Developing Web Applications with ASP.NET and C#
Authors: Hank Meyne, Scott Davis
Venue:  (2002)

:Learn how to create the basic, dynamic, and advanced ASP.NET pages in C#Packed with tips, tricks, and workarounds, this book covers every aspect of developing a Web application for the enterprise using ASP.NET and C#. Written by Microsoft insiders, it shows readers how to create the basic, dynamic, and advanced ASP.NET pages in Microsoft's new C# programming language, and explains how to interact with the database using ADO.NET.The authors review how to transport and display data on the Internet or an Intranet using XML, objects, and Web services. They also explain how to implement security with authentication, integrate important e-commerce issues, and optimize the ASP.NET Web application for optimal performance.Companion Web site features complete source code samples for the applications developed and explained in the book.Microsoft Technologies.NET Platform: The next big overhaul to Microsoft's technologies that will bring enterprise distributed computing to the next level by fully integrating the Internet into the development platform. This will allow interaction between any machine, on any platform, and on any device.Visual Basic.NET: The update to this popular visual programming language will offer greater Web functionality, more sophisticated object-oriented language features, links to Microsoft's new common runtime, and a new interface.ASP.NET: A programming framework (formerly known as Active Server Pages) for building powerful Web-based enterprise applications; can be programmed using VB.NET or C#.C#: Microsoft's new truly object-oriented programming language that builds on the strengths of C++ and the ease of Visual Basic; promises to give Sun's Java a run for its money.
Constructive Floorplanning with a Yield Objective
Venue: Proceedings of the 2nd International Symposium on Quality Electronic Design (2001)

The ability to improve the yield of integrated circuits through layout modification has been recognized, and several techniques for yield enhanced routing and compaction have been developed. Still, yield issues are rarely a factor in the choice of the floorplan mainly due to the tendency to focus on the more important timing and area objectives. Consequently, floorplanning tools have been developed with only these primary objectives in mind. We show in this paper that it is possible to generate a better floorplan with respect to yield, with very little penalty in the main objectives. We describe a constructive floorplanning approach which is based on analytical techniques and produces near optimal floorplans in terms of area utilization, wiring length and yield. 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
The Geobucket Data Structure for Polynomials
Authors: Thomas Yan
Venue:  (1996)

The {\em geobucket\/} data structure is suitable as an intermediate representation of polynomials for performing large numbers of polynomial additions and lead term extractions. A sum involving {$N$} terms has worst-case running time {$O(N\log{N})$} both online and offline, matching or surpassing the obvious/standard alternatives. This makes the geobucket a good choice for performing the reduction step of \grobner\ basis computations.
Geometric Spanners for Wireless Ad Hoc Networks
Authors: Yu Wang, Xiang-Yang Li
Venue: Proceedings of the 22 nd International Conference on Distributed Computing Systems (ICDCS'02) (2002)

We propose a new geometric spanner, for wireless ad hoc networks, which can be constructed efficiently in a distributed manner. It combines the connected dominating set and the local Delaunay graph to form the backbone of wireless network. This new spanner has these following attractive properties: (1) the backbone is a planar graph;(2) the node degree of the backbone is bounded from above by a positive constant;(3) it is a spanner both for hops and length; moreover, we show that, given any two nodes u and v, there is a path connecting them in the backbone such that its length is no more than 6 times of the shortestpath and the number of links is no more than 3 times of the shortest path;(4) it can beconstructed locally and is easy to maintain when the nodes move around;(5) moreover, we show that the computation cost of each node is at most O(d log d), whered is its 1-hop neighbors in the original unit disk graph, and the communication cost of each node is bounded by a constant. Simulation results are also presented for studying its practical performance.
The Umts (Universal Mobile Telecom Standard) Physical Layer Basics,Standard,and Frontend Matters
Authors: Andreas Springer, Robert Weigel
Venue:  (2002)

:This book describes the physical layer of UMTS (Universal Mobile Telecommunication System) which is one of the five members of the IMT-2000 family of standards. It compiles in a clear fashion, the main technical features of the physical layer standard together with a description of the basics digital communications and spread spectrum technology on which UMTS relies. In addition the test cases specified in the standard are described together with their implications on any practical frontend design. The reader will benefit from the standard description which exempts him from studying lots of standardization documents. Additional explanations of the standard and especially the test cases will help to better understand the effects on any frontend system design. Many references are provided for readers interested in in-depth treatments of certain topics.
Tree-width and the monadic quantifier hierarchy
Authors: J. A. Makowsky, J. P. Mariño
Venue: Theoretical Computer Science (2003)

It is well known that on classes of graphs of bounded tree-width, every monadic second-order property is decidable in polynomial time. The converse is not true without further assumptions. It follows from the work of Robertson and Seymour, that if a class of graphs K has unbounded tree-width and is closed under minors, then K contains all planar graphs. But on planar graphs, three-colorability is NP-complete. Hence, if P ≠ NP and on K every existential monadic second-order property is in P, then K has bounded tree-width. In other words, for K closed under minors, K is of bounded tree-width iff all monadic second-order properties are decidable in P.In this note we prove that in order to characterize classes of graphs of bounded tree-width where the monadic quantifier hierarchy collapses, closure under minors can be replaced by closure under topological minors. Closure under minors of K implies that K is in P, whereas we also note that there is a class of graphs K closed under topological minors which is not even r.e.We also show, that closure under induced subgraphs or even under subgraphs alone does not suffice to show that the collapse of the monadic quantifier hierarchy on K implies that K is of bounded tree-width or clique-width.Other characterizations of classes of bounded tree-width in terms of collapses of the monadic quantifier hierarchy to levels above the existential are discussed.
Head Tracking via Robust Registration in Texture Map Images
Authors: Marco La Cascia, John Isidoro, Stan Sclaroff
Venue:  (1997)

Abstract A novel method for 3D head tracking in the presence of large head rotations and facial expression changes is described. Tracking is formulated in terms of color image registration in the texture map of a 3D surface model. Model appearance is recursively updated via image mosaicking in the texture map as the head orientation varies. The resulting dynamic texture map provides a stabilized view of the face that can be used as input to many existing 2D techniques for face recognition, facial expressions analysis, lip reading, and eye tracking. Parameters are estimated via a robust minimization procedure; this provides robustness to occlusions, wrinkles, shadows, and specular highlights. The system was tested on a variety of sequences taken with low quality, uncalibrated video cameras. Experimental results are reported.
The Far Infra Red Molecular Dynamics of Circular Dichroism and Optical Rotatory Dispersion
Authors: M. W. Evans, S. Wozniak, G. Wagniere
Venue:  (1991)

The nature of the far infra red molecular dynamics of circular dichroism (CD) and optical rotatory dispersion (ORD) is investigated with field applied molecular dynamics simulation (FMD) in chiral (S)-CHBrCIF and achiral water ensembles. Rosenfeld tensor symmetries show that femtosecond transients and steady state correlation functions are different in the chiral ensemble but identical in the achiral ensemble for right and left circularly polarised components of a laser.
Transient analysis of traffic generated by bursty sources, and its application to measurement-based admission control
Authors: Michel R.H. Mandjes, M. J.G. Uitert
Venue:  (2000)

The first part of the paper is devoted to a transient analysis of traffic generated by bursty sources. These sources are governed by a modulating process, whose state determines the traffic rate at which the source transmits. The class of modulating processes contains e.g. on/off traffic sources with general on and off times (but is considerably broader). We focus on the probability of extreme fluctuations of the resulting traffic rate, or more precisely, we determine the probability of the number of sources being in the on state reaching a certain threshold, given a measurement of the number of sources in the on state $t$ units of time ago. In particular, we derive large deviations asymptotics of this probability when the number of sources is large. These asymptotics are numerically manageable, and it is empirically verified that they lead to an overestimation of the probability of our interest. The analysis is extended to alternative measurement procedures. These procedures allow to take into account for instance more historic measurements than just one, possibly combined with an exponential weighting of these measurements.\\ In the second part of the paper, we apply the asymptotic calculation methods to gain insight into the feasibility of measurement-based admission control (MBAC) algorithms for ATM or IP networks. These algorithms attempt to regulate the network''s load (to provide the customers with a sufficient Quality of Service), and at the same time achieve an acceptable utilization of the resources. An MBAC algorithm may base acceptance or rejection of a new request on the measured momentary load imposed on the switch or router; if this load is below a given threshold, the source can be admitted. We investigate whether such a scheme is robust under the possible stochastic properties of the traffic offered. Both the burst level (i.e., the distribution of the on and off times of the sources) and the call level (particularly the distribution of the call duration) are taken into account. Special attention is paid to the influence of the bursts, silences, or call durations having a distribution with a `heavy tail''.