ppxscal/embedding_network huggingface dataset:
An Optical Bus Computer Cluster with a deferred cache coherence protocol
Authors: S. Shibayama, K. Hamaguchi, T. Fukui, Y. Sudo, T. Shimoyama, S. Nakamura
Venue: Proceedings of the 1996 International Conference on Parallel and Distributed Systems (1996)

In this paper, we first propose a class of workstation cluster which utilizes optical wavelength-division multiplexing (WDM) technology to connect nodes (work-stations) of the cluster. The Optical Bus Computer Cluster (OBCC) falls in the class of cache coherent non-uniform memory access (CC-NUMA) multiprocessors. The basic topology of the cluster is star-shaped with an optical star-coupler in the center to enable one-hop simultaneous broadcasting of information packets from one node to all other cluster nodes. WDM technology not only multiplies by N times the network bandwidth using a single optical fiber, where N is the degree of wavelength multiplexing, but also provides independent communication paths between pairs of cluster nodes by properly assigning wavelengths to inter-node communication. Then we identify the cache subsystem requirements for the OBCC and propose or deferred cache coherence protocol suitable for the OBCC. The basic coherence maintenance scheme is to lazy-evaluate the cache coherence transactions among cluster nodes, utilizing the weak consistency memory model. By deferring the transactions, it is possible to combine multiple transaction issues into one transaction by accumulating modified status bits in the enhanced cache status fields. Since not only the remote memory access but also coherence transaction are costly operations in CC-NUMA systems, the deferred invocation of coherence transactions is particularly useful in CC-NUMA systems such as OBCC. We then give a performance evaluation by simulation that the coherence protocol effectively reduces coherence transactions, particularly in situations where false sharing of longer cache lines becomes noticeable.
Features of the Logic-and-Probabilistic Risk Theory with Groups of Incompatible Events
Authors: E. D. Solozhentsev
Venue: Automation and Remote Control (2003)

The propositions and characteristics of the logic-and-probabilistic theory of unsuccess risk with groups of incompatible events were presented, as well as examples of unsuccess risk scenarios and logic and probabilistic models. The problem of identification (training) of the risk logic-and-probabilistic model from the statistical data was stated, and a training algorithm was set forth. Statistical, combinatorial, and logic-and-probabilistic methods of risk analysis were described. High precision and robustness of the logic-and-probabilistic models of unsuccess risk were explained, and in terms of these characteristics the models were compared with other theories of risk and classification of objects. The results obtained can be used for modeling, analysis, and management of risks in complex organizational and technical systems.
Optimal Parallel Merging Algorithms on BSR
Venue: Proceedings of the 2000 International Symposium on Parallel Architectures, Algorithms and Networks (2000)

Merging is one of the most fundamental problems in computer science. It is well lcnown that\Omega( N \over p + log log N) time is required to merge two sortedsequences each of length N on CRCW PRAM with pprocessors, where p \leq N log\alpha,N for any constant a. Inthis paper, we describe two optimal O(1) time solutionsto the problem for p = N on BSR (Broadcasting withSelective Reduction). They are the first constant timesolutions to the problem on any model of computation.We also give an optimal solution to the problem forp
Interpolating Polynomials from Their Values
Authors: Richard Zippel
Venue:  (1989)

A fundamental technique used by many algorithms in computer algebra is interpolating polynomials from their values. This paper discusses two algorithms for solving this problem for sparse multivariate polynomials, an updated version of a probabilistic one and a new deterministic technique that uses some ideas due to Ben-Or and Tiwari (1988). In addition, algorithms are presented for quickly finding points that are not zeroes of sparse multivariate polynomials the zero avoidance problem.
The Horus and Ensemble Projects: Accomplishments and Limitations
Authors: Kenneth P. Birman, Robert Constable, Mark Hayden, Jason Hickey, Christoph Kreitz, Robbert Van Renesse, Ohad Rodeh, Werner Vogels
Venue:  (1999)

The Horus and Ensemble efforts culminated a multi-year Cornell research program in process group communication used for fault-tolerance, security and adaptation. Our intent was to understand the degree to which a single system could offer flexibility and yet maintain high performance, to explore the integration of fault-tolerance with security and real-time mechanisms, and to increase trustworthiness of our solutions by applying formal methods. Here, we summarize the accomplishments of the effort and evaluate the successes and failures of the approach.
A Parallel Execution Model for Logic Programming
Authors: Peyyun P Li
Venue:  (1986)

The Sync Model, a parallel execution method for logic programming, is proposed. The Sync Model is a multiple-solution data driven model that realizes AND-parallelism and OR-parallelism in a logic program assuming a message-passing multiprocessor system. AND parallelism is implemented by constructing a dynamic data flow graph of the literals in the clause body with an ordering algorithm. OR parallelism is achieved by adding special Synchronization signals to the stream of partial solutions and synchronizing the multiple streams with a merge algorithm. The Sync Model is proved to be sound and complete. Soundness means it only generates correct solutions and completeness means it generates all the correct solutions. The soundness and completeness of the Sync Model are implied by the correctness of the merge algorithm. A new class of interconnection networks, the Sneptree, is also presented. The Sneptree is an augmented complete binary tree which can simulate an unbounded complete binary tree optimally. Amongst different connection patterns of the Sneptree, some are regular and extensible so as to be well suited for VLSI implementation. A recursive method is presented to generate the H-structure layout of one type of the Sneptree, called the Cyclic Sneptree. A message routing algorithm between any two leaf nodes of the Cyclic Sneptree is also presented. The routing algorithm, which is of O(n) complexity, gives a good approximation to the shortest path. The Sneptree is an ideal architecture for the Sync model, in which a dynamic process tree is constructed. With a simple mapping algorithm, the Sync Model can be mapped onto the Sneptree with highly-balanced load and low overhead. 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
Validating year 2000 compliance
Authors: Arie Deursen, Paul Klint, M. P. A Sellink
Venue:  (1997)

Validating year 2000 compliance involves the assessment of the correctness and quality of a year 2000 conversion. This entails inspecting both the quality of the conversion \emph{process} followed, and of the \emph{result} obtained, i.e., the converted system. This document provides an overview of the techniques that can be used to validate year 2000 compliance. It includes typical code fragments, and a discussion of existing technology, impact analysis, solution strategies, code correction, testing, and tools.
Distributed Java Virtual Machine For Message Passing Architectures
Authors: Mihai Surdeanu
Venue: Proceedings of the The 20th International Conference on Distributed Computing Systems ( ICDCS 2000) (2000)

This paper introduces a distributed shared memory Java Virtual Machine architecture. This project is targeted for any distributed message-passing architecture, and specifically for networks of workstations. The whole system is implemented in user space, which offers portability and flexibility. The memory consistency is provided by one of four protocols implementing Release Consistency. The novelty of the consistency protocols presented is that access faults are avoided by replicating objects ahead-of-time where necessary. The relative performance of these protocols is evaluated for three benchmark applications. Our experimental results indicate that, in the majority of cases, update protocols outperform invalidate protocols.
Simple Cell Interaction for Iterative Contrast Detection
Authors: Marina Kolesnik, Alexander Barlit, Evgeny Zubkov
Venue: Proceedings of the 2002 IEEE International Conference on Artificial Intelligence Systems (ICAIS'02) (2002)

This work describes a novel model for contrast detection inspired by regular spatial structure of simple cells in the visual cortex of mammals. The model employs major cortical connections in the laminar circuitry of extrastriate visual pathways and the area V1 of the visual cortex. The model employs two new features, namely, the iterative processing of visual inputs and amplification of tuned responses of spatially close simple cells in V1. Results show that after several iterations the processing converges to a stable solution while making edge detection being largely contrast independent. The model suppresses spurious noise in the vicinity of contrastive luminance changes while enhancing isolated low-intensity changes. We demonstrate the capabilities of the model by processing synthetic as well as natural images and compare our results to Canny edge detector.
A Neural Network Model for Assisting Project SERENDIP
Authors: Taylor, D, Towsey, M, J. Diederich
Venue:  (1998)

Project SERENDIP currently uses a signal-to-noise ratio threshold method for the extraction of features from power spectra for further analysis. This paper details the results of a small-scale experiment conducted to test the viability of replacing this method with an artificial neural network approach. A simple recurrent network is trained to recognise simulated extra-terrestrial signals in a time-frequency sequence. The output of the network is used as a mask to extract the appropriate features from power spectra. Simulation results for the network integrated into a simple receiver model demonstrate the potential advantage of this approach over current practice.
Modelling of adaptive structures using layerwise models
Authors: J. E. Semedo Garção, C. M. Mota Soares, C. A. Mota Soares, J. N. Reddy
Venue: Proceedings of the sixth conference on Computational structures technology (2002)

This paper deals with the development of finite element formulations of a layerwise theory for laminated plate structures with piezoelectric materials (layers or patches). The formulation includes full electromechanical coupling. Several approximations are used for the problem primary variables in the thickness direction and different interpolation schemes are considered in the surface directions. The predictions of the displacement components, electrical potential, stress components and electrical displacement components, are compared with a three-dimensional closed-form solution for two benchmark problems. A very good agreement is obtained for the models using cubic approximation in the thickness direction. The advantages of these models on the prediction of layer stresses are fully illustrated.
A Backward Error Analysis of a Null Space Algorithm in Sparse Quadratic Programming
Authors: Mario Arioli
Venue:  (1999)

We present a roundoff error analysis of a null space method for solving quadratic programming minimization problems. This method combines the use of a direct $LU$ factorization of the constraints with an iterative solver on the corresponding null space. Numerical experiments are presented, which give evidence of the good performances of the algorithm on sparse matrices.
Event-Based Retrieval from Digital Libraries Containing Streamed Data
Authors: Mohamed Kholief, Stewart Shen, Kurt Maly
Venue: Proceedings of the The International Conference on Information Technology: Coding and Computing (ITCC'00) (2000)

Data streams are a very important source of information for both researchers and ordinary users. Data streams might be video or audio streams or might be a stream of sensor readings, satellite images, etc. Saving data, streams in digital libraries add the advantages of using digital libraries from archival, preservation, administration, access control, etc to this information. For this specific type of digital libraries, event-based retrieval provides an alternative, yet a very natural way of retrieving information. People tend to remember or search by a specific event that happened in the stream better than by the time at which this event happened.In this paper, we describe the organization and services of a prototype digital library system that contains streamed data and enables event-based retrieval from them. We present a preliminary formal definition of data streams and events. We also show some possible applications of this system. We conclude by presenting the ongoing and future extensions to our research.
Curve Finder Combining Perceptual Grouping and a Kalman Like Fitting
Authors: Frédéric Guichard Jean-Philippe Tarel
Venue: Proceedings of the International Conference on Computer Vision-Volume 2 - Volume 2 (1999)

We present an algorithm that extracts curves from a set of edgels within a specific class in a decreasing order of their "length". The algorithm inherits the perceptual grouping approaches. But, instead of using only local cues, a global constraint is imposed to each extracted subset of edgels, that the underlying curve belongs to a specific class.In order to reduce the complexity of the solution, we work with a linearly parameterized class of curves, function of one image coordinate. This allows, first, to use a recursive Kalman based fitting and, second, to cast the problem as an optimal path search in an directed graph. Experiments on finding lane-markings on roads demonstrate that real-time processing is achievable.
Managing adaptive presentation executions in distributed multimedia database systems
Authors: H. Thimm, W. Klas, J. Walpole, C. Pu, C. Cowan
Venue: Proceedings of the 1996 International Workshop on Multi-Media Database Management Systems (IW-MMDBMS '96) (1996)

The paper describes recent progress in research on database system support for executing multimedia presentations. It proposes the general concept of reactive playout management to adjust multimedia presentations. This adjustment can be required due to performance fluctuations as in the absence of end-to-end quality of service guarantees, cost constraints specified by the user and other reasons. A concrete concept to realize performance-based reactive playout management in distributed multimedia database systems is proposed. This covers the identification of respective components in distributed database system architectures along with corresponding algorithms.
Connectionist Networks for Feature Indexing and Object Recognition
Authors: Clark F. Olson
Venue:  (1996)

Feature indexing techniques are promising for object recognition because of their ability to eliminate many feature set matches from consideration without much computation. This work exploits another property of such techniques. They have inherently parallel structure and connectionist network formulations are easy to develop. Once indexing has been performed, a voting scheme such as geometric hashing [Lamdan et al. 1990] can be used to generate object hypotheses in parallel. We give a framework for the connectionist implementation for such indexing and recognition techniques. With sufficient processing elements, recognition can be performed in a small number of time steps. The number of processing elements necessary to achieve peak performance and the fan-in/fan-out required for the processing elements is determined. These techniques have been simulated on a conventional architecture with good results.
Capturing User Access Patterns in the Web for Data Mining
Authors: I-Yuan Lin, Xin-Mao Huang, Ming-Syan Chen
Venue: Proceedings of the 11th IEEE International Conference on Tools with Artificial Intelligence (1999)

Existing methods for knowledge discovery in the Web are mostly server-oriented and approaches taken are affected by the use of proxy servers. As a result, it is difficult to capture individual Web user behavior from the current log mechanism. As an effort to remedy this problem, we develop in this paper methods for design and implementation of an access pattern collection server to conduct data mining in the Web. We also devise an innovative method, called pages conversion, which converts the original Web pages to enciphered ones so that the devised data collection mechanism will not be deliberately bypassed. With the concept of page conversion, the methods we proposed involves a mechanism of software downloading to resolve the difficulty imposed by proxy servers and to effectively capture the Web user behavior. Using the devised mechanism, traversal patterns are generated and compared to those produced by the ordinary Web servers to validate our results. It is shown that the traversal patterns resulting from the devised system are not only more informative but also more accurate than those generated by ordinary Web servers, showing the importance and the usefulness of the mechanism devised.
Experimental Comparison of Scheduling Policies on Coarse-Grain Multiprocessors
Authors: Christopher Connelly
Venue:  (1995)

Scalable shared memory multiprocessors commonly employ replication and the associated coherency maintenance of memory blocks, but differ in the granularity from fine-grain (e.g. cache-coherent multiprocessors) to coarse-grain (e.g. page-based distributed shared memory systems). Regardless of the size of coherency blocks, attaining good performance may depend on the number of copies of cached data staying small, due to the inability of current architectures to support widely shared, writable data. Previous workload characterization studies of fine-grain systems have shown sharing patterns that tend toward small worker sets. Coarse-grain architectures offer scalability advantages unless sharing patterns for larger blocks are considerably less favorable. In the first portion of this dissertation, we investigate data sharing patterns in coarse-grain multiprocessors. Our results are encouraging in that, despite the coarse granularity, worker sets scale reasonably. This has implications for directory protocol design, the scalability of coarse-grain directory protocols, and the exploitation of locality in coarse-grain multiprocessors. In the second portion of this dissertation, we examine techniques to reduce memory system overhead by exploiting the data sharing patterns observed in our workload applications. Distributed shared memory multiprocessors exploit locality of reference by transparently replicating remote data in a processor''s local memory. This automatic replication of data can impose substantial memory system overhead on an application since all replicated data must be kept coherent. We examine the effect of task scheduling on data replication and memory system overhead due to coherency requirements. We show that simple policies using programmer hints can reduce memory coherence overhead and application execution time. Finally, the field of high-performance parallel computing is rapidly expanding to include clusters of commodity workstations. In the final portion of this dissertation, we examine the effectiveness of our scheduling techniques in the more distributed environments that characterize cluster-based parallel computing. We show that as communication becomes more expensive relative to computation, our techniques for reducing memory coherence overhead become more beneficial.
Theory and Simulation of Optical NMR
Authors: M. W. Evans
Venue:  (1991)

A theory and field applied computer simulation (FMD) is developed of magnetisation by a circularly polarised laser directed into the sample tube of a contemporary NMR spectrometer, a technique called "optical NMR." The mechanism considered in this paper involves a non-vanishing term in the energy made up of the product, of the conjugate product, of the laser, the magnetic flux density of the permanent magnet, and the imaginary part of a rank three mediating molecular property tensor, a transition magnetic/electric/electric hyperpolarisability called the "beta tensor." The diagrammatic perturbation calculus and properties of beta close to optical resonance are examined, the point group symmetries and selection rules of beta tabulated for all molecular dynamics and transient ensemble responses mediated by beta, and generalised Langevin Kielich functions given of the beta mediated orientational response of the molecular ensemble. Suggestions are made for the experimental development of optical NMR spectroscopy.
A few logs suffice to build (almost) all trees (I)
Authors: P. L. Erdos, M. A. Steel, L. A. Szekely, T. J. Warnow
Venue:  (1997)

A phylogenetic tree (also called an ``evolutionary tree'''') is a leaf-labelled tree which represents the evolutionary history for a set of species, and the construction of such trees is a fundamental problem in biology. Here we address the issue of how many sequence sites are required in order to recover the tree with high probability when the sites evolve under standard Markov- style (i.i.d.) mutation models. We provide analytic upper and lower bounds for the required sequence length, by developing a new (and polynomial time) algorithm. In particular we show that when the mutation probabilities are bounded the required sequence length can grow surprisingly slowly (a power of log n) in the number n of sequences, for almost all trees.
XML retrieval: what to retrieve?
Authors: Jaap Kamps, Maarten Marx, Maarten de Rijke, Börkur Sigurbjörnsson
Venue: Proceedings of the 26th annual international ACM SIGIR conference on Research and development in informaion retrieval (2003)

The fundamental difference between standard information retrieval and XML retrieval is the unit of retrieval. In traditional IR, the unit of retrieval is fixed: it is the complete document. In XML retrieval, every XML element in a document is a retrievable unit. This makes XML retrieval more difficult: besides being relevant, a retrieved unit should be neither too large nor too small. The research presented here, a comparative analysis of two approaches to XML retrieval, aims to shed light on which XML elements should be retrieved. The experimental evaluation uses data from the Initiative for the Evaluation of XML retrieval (INEX 2002).
From concept to image with computer art graphics
Authors: A. Ursyn
Venue: Proceedings of the IEEE Conference on Information Visualisation (1997)

Discusses how to train computer graphics-oriented students to be able to use the computer to its full artistic potential, with application both of programming and art-related issues. Students create computer art graphics inspired by scientific concepts, to match the curricular content of other courses they are taking concurrently. The integrative visual training involves both the process and the product of the students' work. Due to the integrative instruction of art and science issues, students might learn about specific subject areas by applying visual thinking and inventing subject-related activities which involve visualizing information. Two main methods of integration were applied: (1) integrative project assignments, aimed at provoking the students to apply visual thinking and learning, and (2) art assignments, inspiring the students to create artwork inspired by scientific concepts.