ppxscal/embedding_network huggingface dataset:
Transient Behaviors of TCP-friendly Congestion Control Protocols
Authors: Y. R Yang, Min S Kim, Simon S. Lam
Venue:  (2000)

We investigate the fairness, smoothness, responsiveness, and aggressiveness of TCP and three representative TCP-friendly congestion control protocols: GAIMD, TFRC, and TEAR. The properties are evaluated both analytically and experimentally by studying protocol responses to three network environment changes. The first environment change is the inherent fluctuations in a stationary network environment. We consider three types of sending rate variations: smoothness, short-term fairness, and long-term fairness. For a stationary environment, we observe that smoothness and fairness are positively correlated. We derive an analytical expression for the sending rate coefficient of variation for each of the four protocols. These analytical results match well with experimental results. The other two environment changes we study are a step increase of network congestion and a step increase of available bandwidth. Protocol responses to these changes reflect their responsiveness and aggressiveness, respectively.
Contragredient Transformations Applied to the Optimal Projection Equations
Authors: Dragan Zigic, Layne T. Watson, Christopher A. Beattie
Venue:  (1992)

The optimal projection approach to solving the H2 reduced order model problem produces two coupled, highly nonlinear matrix equations with rank conditions as constraints. It is not obvious from their original form how they can be differentiated and how some algorithm for solving nonlinear equations can be applied to them. A contragredient transformation, a transformation which simultaneously diagonalizes two symmetric positive semi-definite matrices, is used to transform the equations into forms suitable for algorithms for solving nonlinear problems. Three different forms of the equations obtained using contragredient transformations are given. An SVD-based algorithm for the contragredient transformation and a homotopy algorithm for the transformed equations are given, together with a numerical example.
Video and Audio Streams Over an IP/ATM Wide Area Network
Authors: Mark McCutcheon, Mabo R. Ito, Gerald W. Neufeld
Venue:  (1997)

This is a survey of the state of the art in delivering IP services over ATM networks, as it stands in the second quarter of 1997. It also includes a look at the alternatives to that set of technologies. The technology and the choices are changing "on the fly", and have evolved significantly during the course of this project. Moreover, the issues are not exclusively technical, but in many respects reflect the great schism in the data communications world: connection-oriented versus connectionless networks. We have tried to present the technical issues and solutions along with an unbiased overview of the more "philosophical" issues. We indicate how we think the technology and the installed base of equipment is going to develop over the next few years, in order to give a picture of the future of ATM in data networking.
Knowledge Representation Issues in Default Reasoning
Authors: Jane T Nutter
Venue:  (1989)

Most existing approaches to reasoning in uncertainty and with incomplete information appeal to formal theories, with relatively little attention to the phenomena they are intended to capture. This has had two major consequences. First, it has led to the spurious disputes, in which participants criticize alternative approaches in the belief that they are competing, when in fact they are investigating different aspects of related phenomena, and should ultimately be viewed as cooperative efforts. Second, it has led to wasted efforts of models which fail to reflect important aspects of kinds of reasoning which they are trying to capture, because the representational requirements have not been adequately spelled out. This paper delineates several different kinds of reasoning in uncertainty, establishes some directions within the field, and attempts to begin setting some ground rules for representational adequacy.
Stepwise Transformations for Fault-Tolerant Design of CCS Processes
Authors: Tomasz Janowski
Venue:  (1994)

This paper provides an approach to the formal design of distributed, fault-tolerant processes, using the language of CCS and the theory of bisimulations. The novel feature of the method is the language by which hypotheses about faults can be specified and also combined. The development of a fault-tolerant process, under a fault hypothesis, makes use of the structure of this hypothesis. This allows to first design a process which does not tolerate any faults and then to stepwise transform this process to tolerate an increasing variety of faults. We illustrate this approach designing a protocol which ensures a reliable transmission for weak assumptions about the faults of the underlying medium.
Investigation of Parallel Computations: Machines, Tools and Programs
Authors: Roberto Togneri
Venue:  (1994)

Parallel and distributed computing are proving to be the next logical step for high performance computing. As single processor systems approach the limits of current VLSI technology, multiple processor systems will present a feasible architecture for scalable high performance computing and resource utilisation. Furthermore as workstations are becoming more diffuse and morereliant on network technology, distributed computing presents an attractivemeans of optimal utilisation of networked resources. In this report both multi-processor and distributed computing systems are studied in the parallelisation of the VA, Chirp, LBG and Move-Means algorithms common in digital signal processing research. Multi-processors are shown toprovide a more friendly development environment due to the shared memory programming model and better efficiency due to low communication latencies. A workstation cluster is shown to be harder to use for application programmers due to the message-passing model and parallelisation efficiency is lower due to the high communication latencies. The message-passing paradigm both facilitates and enforces optimal parallelisation considerations (like data locality) at the cost of greater effort. The Chirp and LBG algorithms parallelise well on both architectures, but the VA and Move-Means are poor candidates for parallelisation. Issues like development environment, program analysis and debugging, task allocation, migration and load balancing and resource utilisation are shown to be important factors in the use of parallel and distributed computing system.
UNSUPERVISED LEARNING OF DISTRIBUTIONS ON BINARY VECTORS USING TWO LAYER NETWORKS
Authors: Yoav Freund, David Haussler
Venue:  (1994)

We present a distribution model for binary vectors, called the influence combination model and show how this model can be used as the basis for unsupervised learning algorithms for feature selection. The model can be represented by a particular type of Boltzmann machine with a bipartite graph structure that we call the combination machine. This machine is closely related to the Harmonium model defined by Smolensky. In the first part of the paper we analyze properties of this distribution representation scheme. We show that arbitrary distributions of binary vectors can be approximated by the combination model. We show how the weight vectors in the model can be interpreted as high order correlation patterns among the input bits, and how the combination machine can be used as a mechanism for detecting these patterns. We compare the combination model with the mixture model and with principle component analysis. In the second part of the paper we present two algorithms for learning the combination model from examples. The first learning algorithm is the standard gradient ascent heuristic for computing maximum likelihood estimates for the parameters of the model. Here we give a closed form for this gradient that is significantly easier to compute than the corresponding gradient for the general Boltzmann machine. The second learning algorithm is a greedy method that creates the hidden units and computes their weights one at a time. This method is a variant of projection pursuit density estimation. In the third part of the paper we give experimental results for these learning methods on synthetic data and on natural data of handwritten digit images.
On Parallel ELLPACK for Shared Memory Machines
Authors: Calvin J. Ribbens
Venue:  (1990)

This report outlines design goals and criteria for a new version of ELLPACK for shared memory multiprocessors. We discuss several specific issues in detail, and suggest paths for further work. An example is given which illustrates some of the tradeoffs necessary in parallelizing a large and complicated mathematical software package such as ELLPACK. We also raise several important questions that must be dealt with as packages such as ELLPACK evolve along with modern high-performance architectures.
Building the CODER Lexicon: The Collins English Dictionary and Its Adverb Definitions
Authors: Edward A. Fox, Robert C. Wohlwend, Phyllis R. Sheldon, Qi Chen, Robert K. France
Venue:  (1986)

The CODER (COmposite Document Expert/extended/effective Retrieval) project is an investigation of the applicability of artificial intelligence techniques to the information retrieval task of analyzing, storing, and retrieving heterogeneous collections of "composite documents." In order to support some of the processing desired, and to allow experimentation in information retrieval and natural language processing, a lexicon was constructed from the machine readable Collins dictionary of the English Language. After giving background, motivation, and a survey of related work, the Collins lexicon is discussed. Following is a description of the conversion process, the format of the resulting Prolog database, and characteristics of the dictionary and relations. To illustrate what is present and to explain how it relates to the files produced from Webster''s Seventh New Collegiate Dictionary, a number of comparative charts are given. Finally, a summary of adverb definitions is presented, together with a description of defining formula that usually indicate the type of the adverb. Ultimately it is hoped that definitions for adverbs and other words will be parsed so that the relational lexicon being constructed will include many additional relationships and other knowledge about words and their usage.
The Design and Implementation of Concurrent Input/Output Facilities in ACT++ 2.0
Authors: Dennis G. Kafura, Manibrata Mukherji
Venue:  (1992)

ACT++ 2.0 is the most recent version of a class library for concurrent programming in C++. Programs in ACT++ consist of a collection of active objects called actors. Actors execute concurrently and cooperate by sending request and reply messages. An agent, termed the behavior of an actor, is responsible for processing a single request message and for specifying a replacement behavior which processes the next available request message. One of the salient features of ACT++ is its realization of I/O as an actor operation. A special type of actor, called an interface actor, provides a high level interface for a file. Interface actors are sent request messages whenever I/O is necessary and can also transparently perform asynchronous I/O. ACT++ has been implemented on the Sequent Symmetry multiprocessor using the PRESTO threads package.
Distributed Matroid Basis Completion via Elimination Upcast and Distributed Correction of Minimum-Weight Spanning Trees
Authors: D. Peleg
Venue:  (1998)

This paper proposes a time-efficient distributed solution for the matroid basis completion problem. The solution is based on a technique called elimination upcast, enabling us to reduce the amount of work necessary for the upcast by relying on the special properties of matroids. As an application, it is shown that the algorithm can be used for correcting a minimum weight spanning tree computed for a D-diameter network, after k edges have changed their weight, in time O(k+D). 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
Shape from Shading (SFS) und Integration von SFS und Stereo unterperspektivischer Projektion
Authors: An Luo, Hans Burkhardt
Venue:  (1993)

This paper presents a new unified global method of monocular and binocular Shape from Shading (SFS) that can reconstruct both the depth map and slope maps at the same time directly from a grey image or stereo images. The condition of perspective projections which is necessary to consider on the strony relative depth variation is used easily into the integration with the stereo analyse, so that the integrability can be satisfied. By this algorithm, the reliabilty and accuracy of the estimation is improved compared with other SFS methods.
The Optimized Segment Support Map for the Mining of Frequent Patterns
Authors: Carson K Leung, Raymond T. Ng, Heikki Mannila
Venue:  (2001)

Computing the frequency of a pattern is a key operation in data mining algorithms. We describe a simple, yet powerful, way of speeding up any form of frequency counting satisfying the monotonicity condition. Our method, the optimized segment support map (OSSM), is based on a simple observation about data: Real life data sets are not necessarily be uniformly distributed. The OSSM is a light-weight structure that partitions the collection of transactions into m segments, so as to reduce the number of candidate patterns that require frequency counting. We study the following problems: (i) What is the optimal value of m, the number of segments to be used (the segment minimization problem)? (ii) Given a user-determined m, what is the best segmentation/composition of the m segments (the constrained segmentation problem)? For the segment minimization problem, we provide a thorough analysis and a theorem establishing the minimum value of m for which there is no accuracy lost in using the OSSM. For the constrained segmentation problem, we develop various algorithms and heuristics to help facilitate segmentation. Our experimental results on both real and synthetic data sets show that our segmentation algorithms and heuristics can efficiently generate OSSMs that are compact and effective.
A Semantic Model for UNITY
Authors: Zhiming Liu
Venue:  (1989)

This paper develops a semantic model for UNITY that reflects its particular aspects, such as nondeterminism, absence of control flow etc.. The proposed model is a kind of state-transition system within which observations and actions are the basic semantic objects. An alternative semantics for UNITY programs based on different fairness conditions is also defined using this model. Specially, the fairness condition assumed in [CM88] is defined and the UNITY logic based on it is modelled to show how the safety and liveness (progress) properties can be represented. This model is beeing used as the basis for developing some formal techniques for fault-tolerance within a UNITY framework. 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
Continuous Homotopies for the Linear Complementarity Problem
Authors: Layne T. Watson, J. P Bixler, Aubrey B. Poore
Venue:  (1987)

There are various formulations of the linear complementarity problem as a Kakutani fixed point problem, a constrained optimization, or a nonlinear system of equations. These formulations have remained a curiosity since not many people seriously thought that a linear combinatorial problem should be converted to a nonlinear problem. Recent advances in homotopy theory and new mathematical software capabilities such as HOMPACK indicate that continuous nonlinear formulations of linear and combinatorial problems may not be far-fetched. Several different types of continuous homotopies for the linear complementarity problem are presented and analyzed here, with some numerical results. The homotopies with the best theoretical properties (global convergence and no singularities along the zero curve) turn out to also be the best in practice.
FRAME-BASED FAIR QUEUEING: A NEW TRAFFIC SCHEDULING ALGORITHM FOR PACKET-SWITCHED NETWORKS
Authors: Dimitrios Stiliadis, Anujan Varma
Venue:  (1995)

In this paper we introduce and analyze frame-based fair queueing, a novel traffic scheduling algorithm for packet-switched networks. The algorithm provides end-to-end delay bounds identical to those of PGPS (packet-level generalized processor sharing), without the complexity of simulating the fluid-model system in the background as required in PGPS. The algorithm is therefore ideally suited for implementation in packet switches supporting a large number of sessions. Implementations of the algorithm are described for both general packet switches supporting variable packet sizes, and ATM switches supporting fixed-size cells. In addition, we prove that the algorithm is fair in the sense that sessions are not penalized for excess bandwidth they received while other sessions were idle. Frame-based fair queueing belongs to a general class of scheduling algorithms, which we call Rate-Proportional Servers. This class of algorithms provides the same end-to-end delay and burstiness bounds as PGPS, but allows more flexibility in the design and implementation of the algorithm. We provide a systematic analysis of this class of schedulers and obtain bounds on their fairness.
Givens and Householder Reductions for Linear Least Squares on a Cluster of Workstations
Authors: Omer Egecioglu
Venue:  (1995)

We report on the properties of implementations of fast-Givens rotation and Householder reflector based parallel algorithms for the solution of linear least squares problems on a cluster of workstations. It is shown that the Givens rotations enable communication hiding and take greater advantage of parallelism than Householder reflectors, provided the matrices are sufficiently large.
Generalization to Novel Images in Upright and Inverted Faces
Authors: Y. Moses, S. Ullman, S. Edelman
Venue:  (1993)

An image of a face depends not only on its shape, but also on the viewing position, illumination conditions, and facial expression. Any face recognition system must overcome the changes in face appearance induced by these factors. To assess the ability of human vision to genralize across changes in illumination and pose of faces, we studied the performance of subjects in a discrimination task with eiether upright or inverted faces. Subjects first learned to discriminate among images of three faces, taken under fixed viewing position an illumination. They were then tested on images of the same faces taken under all combinations of four illuminations and five viewing positions. For upright faces, we found remarkably good generalization to novel conditions. For inverted faces, the generalization to novel views was significantly worse, although the performance on the training images was similar in both cases.
Representing Metadata in the ADAMS Database System
Authors: John L. Pfaltz, David R. Mikesell, William R. Emael
Venue:  (1998)

A major concern of environmental scientists, and others with long term data requirements, has been the establishment of metadata standards so that data recorded today will be accessible 50 to 100 years hence. We contend that more important than the standards themselves will be the context in which they can be represented and can evolve as new requirements and technologies emerge. In this paper, we discuss an object oriented language which facilitates both the representation of metadata as well as its graceful evolution.
TRANSIENT ANALYSIS OF INTERCONNECTS WITH NONLINEAR DRIVER USING MIXED EXPONENTIAL FUNCTION APPROXIMATION
Authors: Haifang Liao, Rui Wang, Wayne W Dai
Venue:  (1993)

The timing-driven routing of a critical net can be implemented as a delay-bounded minimum Steiner tree. This routing tree has the path delays always limited no larger than a delay bound D, while the total wire length is minimized. The delay bound is usually specified at the system/logic design stage. The routing maintains this delay bound to guarantee the correct timing of the finally implemented system in physical layout. We propose a new algorithm of constructing delay bounded minimum Steiner tree. This algorithm is designed based on the observation that this tree can be obtained based on the trade-off between two other special types of Steiner tree: (1) minimum Steiner tree and (2) minimum path delay Steiner tree, by taking into account of a delay bound D. We also proposed a new algorithm of constructing the minimum delay Steiner tree. During the tree growing, the Elmore delay is incremently updated in constant time. These novel Steiner tree algorithms have been applied on a clock routing scheme for multi-chip modules based on area pad interconnections.
Analysis and Synthesis of Environmental Sounds
Authors: V. Guggiana, A. Darvishi, E. Munteanu, H. Schauer, M. Motavalli, M. Rauterberg
Venue:  (1995)

This technical report describes steps toward synthesis of environmental sounds like impact, bouncing, breaking, scraping and other impact sounds.
Numeration models of $\lambda$B-Calculus
Authors: K, Akira a
Venue:  (1984)

Numeration models of extensional $\lambda$-calculus have been studied (see [5,7]). In this paper, we study numeration models of $\lambda \beta$-calculus. Engeler''s graph algebra construction [3] is applied to the category of numerations and is used as a tool to obtain numeration models of $\lambda \beta$-calculus. Several classes of numeration models are studied and several examples of them are presented.
General Framework, Stability and Error Analysis for Numerical Stiff Boundary Value Methods
Authors: Uri Ascher, R. M. Mattheij
Venue:  (1987)

This paper provides a general framework, called ``theoretical multiple shooting'''', within which various, numerical methods for stiff boundary value ordinary differential problems can be analyzed. A global stability and error analysis is given, allowing (as much as possible) the specificities of an actual numerical method to come in only locally. We demonstrate the use of our results for both one-sided and symmetric difference schemes. The class of problems treated includes some with internal (e.g. ``turning point'''') layers.
Selection Networks
Authors: Nicholas Pippenger
Venue:  (1990)

We establish an upper bound asymptotic to $2n \log_{2}n$ for the number of comparators required in a network that classifies $n$ values into two classes each containing $n/2$ values, with each value in one class less than or equal to each value in the other. (The best lower bound known for this problem is asymptotic to $(n/2) \log_{2}n.$)