ppxscal/embedding_network huggingface dataset:
Deadlock Properties of Queueing Networks with Finite Capacities and Multiple Routing Chains
Authors: Jorg Liebeherr, Ian F. Akyildiz
Venue:  (1994)

Blocking in queueing network models with finite capacities can lead to deadlock situations. In this paper, deadlock properties are investigated in queueing networks with multi- ple routing chains. The necessary and sufficient conditions for deadlock-free queueing networks with blocking are pro- vided. An optimization algorithm is presented for finding deadlock-free capacity assignments with the least total capacity. The optimization algorithm maps the queueing net- work into a directed graph and obtains the deadlock freedom conditions from a specified subset of cycles in the directed graph. In certain network topologies, the number of deadlock freedom conditions can be large, thus, making any optimiza- tion computationally expensive. For a special class of topo- logies, so-called {\m tandem networks}, it is shown that a minimal capacity assignment can be directly obtained without running an optimization algorithm. Here, the solution to the minimal capacity assignment takes advantage of the regular topology of tandem networks. March 21, 1994
Labeling Schemes for Flow and Connectivity,
Authors: M. Katz, N. A. Katz, A. Korman, D. Peleg
Venue:  (2001)

This paper studies labeling schemes for flow and connectivity functions. A flow labeling scheme using O(logn?log[^(w)])-bit labels is presented for general n-vertex graphs with maximum (integral) capacity [^(w)]. This is shown to be asymptotically optimal. For edge-connectivity, this yields a tight bound of Q(log2 n) bits. A k-vertex connectivity labeling scheme is then given for general n-vertex graphs using at most 3logn bits for k = 2, 5logn bits for k = 3 and 2klogn bits for k < 3. Finally, a lower bound of W(klogn) is established for k-vertex connectivity on n-vertex graphs where k is polylogarithmic in n.
Experimental Implementation of Dynamic Access Ordering
Authors: S. A. McKee, R. H. Klenke, A. J. Schwab, Wm Wulf, S. A. Moyer, C. Hitchcock, J. H. Aylor
Venue:  (1993)

As microprocessor speeds increase, memory bandwidth is rapidly becoming the performance bottleneck in the execution of vector- like algorithms. Although caching provides adequate performance for many problems, caching alone is an insufficient solution for vector applications with poor temporal and spatial locality. More- over, the nature of memories themselves has changed. Current DRAM components should not be treated as uniform access-time RAM: achieving greater bandwidth requires exploiting the charactistics of components at every level of the memory hierarchy. This paper describes hardware-assisted access ordering and our hardware development effort to build a Stream Memory Controller (SMC) that implements the technique for a commercially available high-performance microprocessor, the Intel i860. Our strategy augments caching by combining compile-time detection of memory access patterns with a memory subsystem that decouples the order of requests generated by the processor from that issued to the memory system. This decoupling permits requests to be issued in an order that optimizes use of the memory system.
Current State of Data Mining
Authors: Darren T. Drewry, Lin Gu, A. B Hocking, Kyoung Kang, Robert C. Schutt, Christopher M. Taylor, John L. Pfaltz
Venue:  (2002)

This report is a compendium of results uncovered in CS 851, spring semester 2002. Our goal is to provide direction to other graduate students who want to explore the fascinating field of "data mining." Be aware that this represents the topics and the papers that we found most interesting. We made no attempt to be either `fair'' or to be `comprehensive'' as in a Computing Reviews article. Instead we tried to pick just one or two references in each of our interest areas that were both relatively recent and, in our opinion, worth reading. Their bibliographies can direct a reader to other sources.
The implementation of a multi-agent system for construction claims negotiation
Authors: Z. Ren, C. J. Anumba, O. O. Ugwu
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

Negotiation is an important stage in construction claims management process. Unfortunately, most construction claims negotiations are conducted inefficiently due to various reasons. The recent development of multi-agent systems provides an innovative approach to facilitating various negotiations. This research has developed a multi-agent system for construction claims negotiation (MASCOT) to resolve the inefficiency problem. This paper discusses the key points of the MASCOT model. Of particular interest is the computer implementation of the developed MASCOT model using the ZEUS agent building toolkit.
A Survey of Database Support for Process-Centered SoftwareDevelopment Environments.
Authors: Dimitrios Tombros, Andreas Geppert
Venue:  (1995)

Database management systems (DBMSs) are a basic component of integrated project support environments (IPSEs). They are used for the modeling, storage and management of data produced by various software tools during the development process. In environments where the development process is explicitly supported (process-centered software development environments - PCDEs), processes can also be modelled, persistently stored and managed. In the present paper, we survey how DBMSs are integrated in the architec- ture of PCDEs and in particular how DBMS mechanisms are used to provide parts of their functionality. The systems we consider are Adele/Tempo, ALF, Arcadia, Epos, Marvel/Provence, Merlin, Oikos, SPADE, and several commercial systems. A number of open issues with respect to database support in these PCDEs are identified and discussed.
Elimination Forest Guided 2D Sparse LU Factorization
Authors: Kai Shen, Xiangmin Jiao, Tao Yang
Venue:  (1998)

Sparse LU factorization with partial pivoting is important for many scientific applications and delivering high performance for this problem is difficult on distributed memory machines. Our previous work has developed an approach called $S^*$ that incorporates static symbolic factorization, supernode partitioning and graph scheduling. This paper studies the properties of elimination forests and uses them to guide supernode partitioning/amalgamation and execution scheduling. The new design with 2D mapping effectively identifies dense structures without introducing too many zeros in the BLAS computation and exploits asynchronous parallelism with low buffer space cost. The implementation of this code, called $S^+$, uses supernodal matrix multiplication which retains the BLAS-3 level efficiency and avoids unnecessary arithmetic operations. The experiments show that $S^+$ improves our previous code substantially and can achieve up to 11.04GFLOPS on 128 Cray T3E 450MHz nodes, which is the highest performance reported in the literature.
Simple Alternate Routing for Differentiated Services Networks
Authors: Stephen D. Patek, Raja Venkateswaran, Jorg Liebeherr
Venue:  (2000)

Recent work on differentiated services in the Internet has defined new notions of Quality of Service (QoS) that apply to aggregates of traffic in networks with coarse spatial granularity. Most proposals for differentiated services involve traffic control algorithms for aggregate service levels, packet marking and policing, and preferential treatment of marked packets in the network core. The issue of routing for enhancing aggregate QoS has not received a lot of attention. This study investigates the potential benefit of using alternate routing strategies in support of differentiated services. We propose a traffic control scheme, called Simple Alternate Routing, wherein portions of unmarked packet flows can be assigned to alternate paths through a Service Provider Network (SPN) in response to congestion feedback information. The scheme is simple, requiring only minor changes to the SPN border routers so that alternately routed packets can be tunneled via conventional paths to an intermediate border node and then tunneled from there to the original egress border node. We present distributed algorithms for (1) discovering congestion within the SPN, and (2) allocating traffic to alternate paths that are uncongested. We have implemented the scheme in a packet-level simulation, and we have examined the transient response of the algorithm to perturbations in the nominal traffic levels experienced by the SPN. The experimental study of this paper provides some understanding of the scheme''s ability to adapt in routing packets around congestion. Our results indicate that the alternate routing framework shows promise and warrants further consideration.
The Global Stability of a Rigid Solid Supported by Elastic Columns
Authors: William I. Thacker, C. Y. Wang, Layne T. Watson
Venue:  (1994)

A new stability index, the global critical load, is advocated. This index is useful for flexible structures prone to large disturbances such as earthquakes. A symmetric rigid body supported by flexible legs is studied in detail. The nonlinear equilibrium equations are solved and the results show that global stability depends heavily on the height of the mass center and the distance between the legs.
A Commuting Diagram Relating Threaded and Non-threaded JVM Models
Authors: George Porter
Venue:  (2001)

We establish a commuting diagram that relates two models of the Java Virtual Machine (JVM). The first model, M3, supports much of Java, including classes, objects, and dynamic method resolution. The second model, M4, builds upon M3 by adding threads, monitors, and synchronized methods. We describe a theorem, Main, that asserts that running certain "single-threaded" states on M4 is equivalent to transforming those states to the domain of M3, running the transformed state there, and translating the result back to the domain of M4. We define the criteria we use to determine if the resulting states are equivalent, and we define our notion of "single-threaded". We then discuss a few lessons learned during the development of Main.
Efficient object-oriented implementation of boundary element software
Authors: I. A. Jones, P. Wang, A. A. Becker, D. Chen, T. H. Hyde
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

This paper describes an experiment in the writing of an object-oriented boundary element (BE) system in Microsoft Visual C++ intended to serve two substantially different purposes. One is the conventional (forward) BE system for the solution of solid mechanics problems to find stresses etc. from a known set of boundary conditions. The other is to implement an inverse BE technique to find the set of boundary conditions from photoelastic data that relate to the difference of principal stress and their orientations at chosen interior points.The initial attempt was to design the system as a "purist" object-oriented system in which container classes were used to represent all arrays, matrices etc. in order for the arrays to have in-built intelligence such as dynamic resizing. This was believed to be the reason for the running time of the program being typically two or more orders of magnitude slower than the corresponding FORTRAN program.The present design focuses on the construction of the BE Model class and its members: Element class and Node class etc. representing real-world entities. These describe the key features of a BE approach and can only be properly implemented using object-oriented programming technology. Conventional C/C++ array, pointer and reference data types are used inside classes and their derived classes. The resulting system not only has the advantages of the OOP technique but also more readable code and faster implementation CPU time even compared to the corresponding FORTRAN code.
DATA DEPENDENT OPTIMIZATIONS FOR PERMUTATION VOLUME RENDERING
Authors: Craig M. Wittenbrink, Kwansik Kim, Alex T. Pang
Venue:  (1996)

Volume rendering or volume visualization is an algorithm for creating images from three-dimensional and four-dimensional data sets, without computing intermediate surface representations. Because of the inherent O(N^3) run time, numerous approximations are used to provide interactivity. As compute platforms have become more capable in their operations per second, and in their memory capacities, the requirements of volume rendering become more and more advanced. The goal of application users is high fidelity renderings of medical, simulation, and remotely sensed data sets. Interactivity provides a tractable means for setting the many input parameters, but interactivity is challenging because of the run time complexity. We investigate the further optimization of massively parallel algorithm solutions, in an effort to have the efficiency of the parallel approaches reach that of sequential ones, without sacrificing fidelity. This paper discusses experiments in extending permutation warping on the MasPar MP-2 implementation to include data dependent coherency optimizations, and object space to screen space precompositing communication savings. We start with a description of the base algorithm, and then describe the extensions, showing results of nearly 400% speed improvement or a factor of 5 speedup.
Abstract Geometry for Design in an Empirical Modelling Context
Authors: W. M. Beynon, R. Cartwright, A. Cartwright, Y. P. Yung
Venue:  (1996)

We review research from an agenda set out in a previous paper, which investigated the application of definitive programming principles to the implementation of CAD systems. This has led us to the development of a new Empirical Modelling paradigm. We outline the principles of Empirical Modelling, and explain and illustrate the significance and potential role of definitive notations for shape such as CADNO, Eden CAD and HyperJazz in this context. We also describe the motivation for Empirical Modelling as a modelling method for open development that can assist the integration of geometric modelling, non-geometric modelling, and meta-modelling aspects of concurrent engineering.
VERITY VISUALIZATION: VISUAL MAPPINGS
Authors: Craig Wittenbrink, Alex Pang, Suresh Lodha
Venue:  (1995)

Visualized data often has dubious origins. One way to define data lineage is by describing the uncertainty. In addition, different forms of uncertainty and errors are also introduced as the data is derived, transformed, interpolated, and finally rendered. In the absence of integrated presentation of data and its associated uncertainty, the analysis of the visualization is incomplete at best and often leads to inaccurate or incorrect conclusions. This paper presents several techniques of presenting data together with uncertainty. The idea behind these techniques can be applied to both spatial (e.g. surface) and temporal (i.e. animation) domains. We describe these techniques of representing the truths about the data as verity visualization. The same techniques can also be used to make the users aware of the data quality or to emphasize and draw their attention to the uncertainty.
Report on Quasi-Experiment for Evaluating SEES
Authors: Arthur James, Frakes William, Gupta Sanjay, Cannon Martha, Groener Markus, Khan Zakia
Venue:  (1995)

The purpose of this document is to describe the design and execution of the quasi-experiment conducted in the Department of Computer Science, Virginia Tech, in accordance with the procedures described in the document, "An Experimental Design for Evaluating SEES" prepared for NASA under contract NASI-19610, Task 17. (Hereafter that report is called the general design document.) The quasi-experiment serves three important purposes. First, the quasi-experiment is the proof of concept of the general experiment design. It shows that the procedures defined in the general experiment design can be implemented. Second, provides details for setting up a true experiment: identifying the research hypothesis, designing the investigation, selecting various variables, procedures, and controls, measuring the variables, and evaluating the results. Third, any insights revealed during the course of the quasi-experiment can be incorporated in the costly true experiment, thus providing a cost-effective experimental methodology. This report contains sufficient information so that the quasi-experiment can be replicated at an appropriate level of abstraction. We also document and interpret all the results of the quasi-experiment.
Representation of Similarity in 3D Object Discrimination
Authors: S. Edelman
Venue:  (1994)

How does the brain represent visual objects? In simple perceptual generalization tasks, the human visual system performs as if it represents the stimuli in a low-dimensional metric psychological space. In theories of 3D shape recognition, the role of feature-space representations (as opposed to structural or pictorial descriptions) has been for a long time a major point of contention. If shapes are indeed represented as points in a feature space, patterns of perceived similarity among different objects must reflect the structure of this space. The feature space hypothesis can then be tested by presenting subjects with complex parameterized 3D shapes, and by relating the similarities among subjective representations, as revealed in the response data by multidimensional scaling, to the objective parameterization of the stimuli. The results of four such tests, reported below, support the notion that discrimination among 3D objects may rely on a low-dimensional feature space representation, and suggest that this space may be spanned by explicitly encoded class prototypes. 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
A software with integrated graphics platform for limit analyses of geotechnical problems
Authors: L. Santos da Silva, M. M. Farias, C. L. Sahlit
Venue: Proceedings of the eighth international conference on The application of artificial intelligence to civil and structural engineering computing (2001)

This paper presents the development of software with a CAD graphics interface, which implements a numerical formulation for plastic limit analyses of geotechnical problems. The formulation combines finite element discretisation and optimisation methods based on mathematical programming techniques applied to plane strain conditions. The graphics interface was coded programmed using the object oriented Delphi language. Computational routines for the generation of the governing system of equations were coded using Fortran 95 language to created dynamic link libraries (DLL) which were linked to the visual interface. The failure mechanism can be visualized with the same interface or, alternatively, by means of another module written with C++, which uses graphical routines of the OpenGL library. The software has the capability to import and export files in text (ASCII) or DXF formats. The later format allows good interactivity with graphics editors such as AutoCad and Microstation.
Multiresolution Image Segmentation
Authors: A. Bhalerao, R. G. Wilson
Venue:  (1989)

The segmentation of images into regions that have some common property is a fundamental problem in image processing. Traditional approaches to segmentation have been either edge based or region based. It is clear, however, that a multiresolution approach, where image properties are measured at varying scales, is the only way to overcome the inherent uncertainty between the class of a region and its position. A review is presented of both boundary and region bsed schemes concentrating on multiresolution methods. Taking boundary information as input, these operators can detect features such as corners, and could be employed to provide shape information in a segmentation scheme. A new quad-tree segmentation method is described and some initial results presented.
A New Explanation of the Glitch Phenomenon
Authors: James H. Anderson, Mohamed G. Gouda
Venue:  (1989)

We consider a discrete model for asynchronous circuits and show that, under very mild restrictions, this model excludes the existence of glitch-free arbiters. This result contradicts a long standing conjecture that the nonexistence of glitch-free arbiters is due to the continuous nature of such circuits.
Filtering Normal Maps and Creating Multiple Surfaces
Authors: Alain Fournier
Venue:  (1992)

``Bump'''' mapping is a variant of texture mapping where the texture information is used to alter the surface normal. Current techniques to pre-filter textures are all relying on the fact that the texture information can be linearly "factored out" of the shading equation, and therefore can be pre-averaged in some way. This is not the case with bump maps, and those techniques fail to filter them correctly. We propose here a technique to pre-filter bump maps by building a pyramid where each level stores distributions of normal vectors reconstructed from the distribution given by the underlying bump map. The distributions are represented as sums of a small number of Phong-like spreads of normal vectors. The technique, besides allowing an effective and smooth transition between a bump map and a single surface description, gives rise to the concept of a multiple surface, where each point of the single surface is characterized by more than one normal vector. This allows the description of visually complex surfaces by a trivial modification of current local illumination models. When a surface has an underlying microstructure, masking and self-shadowing are important factors in its appearance. Along with the filtering of normals we include the filtering of the masking and self-shadowing information. This is accomplished by computing the limiting angles of visibility and their variance along the two texture axes for the reconstructed distribution of normals. These techniques allow the modeling of any surface whose microstructure we can model geometrically. This includes complex but familiar surfaces such as anisotropic surfaces, many woven cloth, and stochastic surfaces.
Confluence of Processes and Systems of Objects
Authors: Xinxin Liu, D. J. Walker
Venue:  (1994)

An extension to the theory of confluence in the process calculus CCS is presented. The theory is generalized to an extension of the 9-calculus. This calculus is used to provide semantics by translation for a parallel object-oriented programming language. The confluence theory is applied to prove the indistinguishability in an arbitrary program context of two class definitions which generate binary tree data structures one of which allows concurrent operations.