ppxscal/embedding_network huggingface dataset:
Further Considerations on Residual-Free Bubbles for Advective-Diffusive Equations
Authors: F. Brezzi, L. P. Franca, A. Russo
Venue:  (1997)

We further consider the Galerkin method for advective-diffusive equations in two-dimensions. The finite dimensional space employed is of piecewise polynomials enriched with residual-free bubbles (RFB). We show that, in general, this method does not coincide with the SUPG method, unless the piecewise polynomials are spanned by linear functions. Furthermore, a simple stability analysis argument displays the effect of the RFB on the reduced space of piecewise polynomials, which is not equivalent to streamline diffusion for bilinears, in some situations.
New Bounds on Crossing Numbers
Authors: Pach Janos, Spencer Joel, Toth Geza
Venue:  (1999)

The crossing number, ${\mbox {cr}}(G)$, of a graph $G$ is the least number of crossing points in any drawing of $G$ in the plane. Denote by $\kappa(n,e)$ the minimum of ${\mbox {cr}}(G)$ taken over all graphs with $n$ vertices and at least $e$ edges. We prove a conjecture of P. Erd\H os and R. Guy by showing that $\kappa(n,e)n^2/e^3$ tends to a positive constant as $n\rightarrow\infty$ and $n\ll e\ll n^2$. Similar results hold for graph drawings on any other surface of fixed genus. We prove better bounds for graphs satisfying some monotone properties. In particular, we show that if $G$ is a graph with $n$ vertices and $e\ge 4n$ edges, which does not contain a cycle of length four (resp. six), then its crossing number is at least $ce^4/n^3$ (resp. $ce^5/n^4$), where $c<0$ is a suitable constant. These results cannot be improved, apart from the value of the constant. This settles a question of M. Simonovits.
ObServer: A Storage System for Object-Oriented Applications
Authors: Mary F. Fernandez, Stanley B. Zdonik, Alan N. Ewald
Venue:  (1990)

ObServer is a storage system designed to support object-oriented applications such as computer-aided design systems, interactive programming environments and object-oriented databases. For these systems to be used effectively, the underlying storage server must support interactive transactions, provide share access to objects and perform efficiently in a distributed workstation environment. In this paper, we present the design and implementation of ObServer, consider its limitations and discuss areas of current and future research. We also provide performance statistics obtained from three types of example databases.
A Conceptual Model for Pervasive Computing
Authors: Laurent Ciarletta, Alden Dima
Venue: Proceedings of the 2000 International Workshop on Parallel Processing (2000)

As an emerging field, pervasive computing has not had the opportunity to develop a conceptual model similar to the OSI Reference Model used to describe computer networks. Such a model would be useful in properly classifying design issues and providing needed context. Inspired by the layers of abstraction provided by the OSI Reference Model, we present our Layered Pervasive Computing (LPC) model to facilitate discussion and analysis of pervasive computing systems by providing a much-needed conceptual framework. A key feature of our model is its representation of the human user at each layer of abstraction of the model. We will then use our model to analyze a research prototype created as part of our Aroma pervasive computing project. This analysis is illustrative because it quickly reveals issues that must be addressed to realize our research prototype as a commercial product.
Scaling an Object-Oriented System Execution Visualizer through Sampling
Authors: Andrew Chan, Reid Holmes, Gail C. Murphy, Annie T. T. Ying
Venue: Proceedings of the 11th IEEE International Workshop on Program Comprehension (2003)

Increasingly, applications are being built by combining existing software components. For the most part, a software developer can treat the components as black-boxes. However, for some tasks, such as when performance tuning, a developer must consider how the components are implemented and how they interact. In these cases, a developer may be able to perform the task more effectively by using dynamic information about how the system executes. In previous work, we demonstrated the utility of a tool, called AVID (Architectural VIsualization of Dynamics), that animates dynamic information in terms of developer-chosen architectural views. One limitation of this earlier work was that AVID relied on trace information collected about the system's execution; traces for even small parts of a system's execution can be enormous, limiting the duration of execution that can be considered. To enable AVID to scale to larger, longer-running systems, we have been investigating the visualization and animation of sampled dynamic information. In this paper, we discuss the addition of sampling support to AVID, and we present two case studies in which we experimented with animating sampled dynamic information to help with performance tuning tasks.
Real Functions for Representation of Rigid Solids
Authors: Vadim Shapiro
Venue:  (1991)

A range of values of a real function $f$ : $E^{d} $\rightarrow \Re$ can be used to implicitly define a subset of Euclidean space $E^{d}$. Such `implicit functions'' have many uses in geometric and solid modeling. This paper focuses on the properties and construction of real functions for the representation of rigid solids (compact, semi-analytic, and regular subsets of $E^{d}$). We review some known facts about real functions defining compact semi-analytic sets, and their applications. The theory of $R$-functionsdeveloped in [Rva82] provides means for constructing real function representations of solids described by the standard (non-regularized) set operations. But solids are not closed under the standard set operations and such representations are rarely available in modern modeling systems. More generally, assuring that a real function $f$ represents a regular set may be difficult. Until now, the regularity has either been assumed, or treated in an ad hoc fashion. We show that topological and extremal properties of real functions can be used to test for regularity, and discuss procedures for constructing real functions with desired properties for arbitrary solids.
MCSA Self-Paced Training Kit: Managing a Microsoft Windows 2000 Network Environment (Exam 70-218)
Authors: Microsoft Corporation
Venue:  (2002)

:Official Microsoft study guide for managing a Microsoft Windows 2000 network environment. This official MCSA Training Kit teaches system administrators how to manage a Microsoft Windows-based network environmentas they prepare for MCP Exam 70-218, a core requirement on the new Microsoft Certified Systems Administrator (MCSA) track. Students learn through an integrated system of skill-building lessons, hands-on exercises, and self-assessment tools. Topics map directly to the objectives measured by the exam, including managing file, print, and Web resources; configuring network infrastructure; monitoring servers and client computers; managing Active Directory organization units and Group Policy; and implementing and troubleshooting remote access. An economical alternative to classroom instruction, this MCSA Training Kit enables students to set their own pace and learn by doing! Offers in-depth instruction on how to manage a Microsoft Windows network environment Helps prepare certification candidates for elective MCP Exam 70-218, a core credit toward MCSA certification and an elective on the MCSE track Features entire study guide on CD-ROMfor easy searches and reference
Schemes of Evolution Strategies
Authors: Sergey I. Rodzin
Venue: Proceedings of the 2002 IEEE International Conference on Artificial Intelligence Systems (ICAIS'02) (2002)

Theoretical and some practical problems of evolution strategies (ES) construction are considered. In contrast to genetic algorithms ES reflect the evolution progress on the phenotype level. The ES basic scheme is analyzed; variants of basic algorithm modification and adaptation for different optimization tasks are investigated. The problems of evaluation of selection schemes and ES convergence computing complexity are analyzed. 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
Regularity results for stochastic Navier-Stokes equations
Authors: Benedetta Ferrario
Venue:  (1997)

Regularity results for the 2D Navier-Stokes equations perturbed by a white noise term are presented. First of all, we remark that a cylindrical Wiener process is not enough to obtain any solution for the 2D case. Therefore, starting from the analysis of the problem under the weakest assumption on the noise, the framework to prove the existence of a weak solution is introduced. The study of the stochastic Navier-Stokes equations is divided into two subproblems; results on the linear Ornstein-Uhlenbeck equation are obtained by means of It\^{o} calculus, whereas Galerkin method is applied to the other non-linear random equation. Moreover, regular solutions are investigated, obtaining strong and smooth solutions. According to the regularity of the covariance of the Wiener process, remarks on different results on the existence and/or uniqueness are provided. EMAIL:: ian@microian.ian.pv.cnr.it 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
Dynamic and I/O-Efficient Algorithms for Computational Geometry and Graph Problems: Theoretical and Experimental Results
Authors: Yi Chiang
Venue:  (1995)

As most important applications today are large-scale in nature, high-performance methods are becoming indispensable. Two promising computational paradigms for large-scale applications are dynamic and I/O-efficient computations. We give efficient dynamic data structures for several fundamental problems in computational geometry, including point location, ray shooting, shortest path, and minimum-link path. We also develop a collection of new techniques for designing and analyzing I/O-efficient algorithms for graph problems, and illustrate how these techniques can be applied to a wide variety of specific problems, including list ranking, Euler tour, expression-tree evaluation, least-common ancestors, connected and biconnected components, minimum spanning forest, ear decomposition, topological sorting, reachability, graph drawing, and visibility representation. Finally, we present an extensive experimental study comparing the practical I/O efficiency of four algorithms for the orthogonal segment intersection problem with large-scale test data. The experiments provide detailed quantitative evaluation of the performance of the four algorithms, and the observed behavior of the algorithms is consistent with their theoretical properties.
Cryptography: It''s Not Just For Electronic Mail Anymore
Authors: J. D Tygar, Bennet Yee
Venue:  (1993)

We extend cryptographic techniques to the protection of the application of stamps for mail. We show how to provide electronic stamps (using off-the-shelf bar code technology to represent a cryptographic message) to use in a fully integrated franking system that provides protection against: 1. Tampering with postage meter to given the user additional credit; 2. Forged or copied electronic stamps; 3. Unauthorized use of a postage meter; and 4. Stolen postage meters. We relate the question of electronic stamps to broader issues in electronic currency and secure coprocessors.
Parallel Programming Languages: Do They Meet the Needs of Scientists and Engineers?
Authors: Cherri M. Pancake, Donna Bergmark
Venue:  (1989)

Although computer scientists use parallel programming languages to model concurrency, scientists and engineers approach parallelism with a different objective. The physical world they model is inherently parallel, but scientific programmers have become accustomed to using sequential techniques for its study. It is the ability to handle massive amounts of data that motivates their conversion to parallelism. This report considers the current state of the art of parallel programming languages from the perspective of scientists and engineers. It reviews the problem-solving strategies commonly employed by scientific programmers and compares them with the conceptual models for parallelism supported by high-level programming languages available to the general user community. The fact that existing languages were designed and implemented by members of the computer science profession is reflected in the prevalence of features representing that community''s view of parallelism. Consequently, scientific programmers are unlikely to find language models that map cleanly to their problem-solving approaches.
Unsupervised Image Classification with a Hierarchical EM Algorithm
Authors: Annabelle Chardin, Patrick Pérez
Venue: Proceedings of the International Conference on Computer Vision-Volume 2 - Volume 2 (1999)

This work takes place in the context of hierarchical stochastic models for the resolution of discrete inverse problems from low level vision. Some of these models lie on the nodes of a quad-tree which leads to non-iterative inference procedures. Nevertheless, if they circumvent the algorithmic drawbacks of grid-based models (computational load and/or great dependence on the initialization), they admit modeling shortcomings (cumbersome and somehow artificial). We investigate a new hierarchical stochastic model which takes benefit from both the spatial and the hierarchical prior modelings. The independence graph is based on a tree which has been pollarded with the nodes at the coarsest resolution exhibiting a grid-based interaction structure. For this class of models, we address the critical problem of parameter estimation. To this end, we derive an EM algorithm on the hybrid structure which mixes an exact EM algorithm on each subtrees and a low cost Gibbsian EM algorithm on the coarse spatial grid. Experiments on a synthetic image and on multi-spectral satellite images are reported.
On the total/sub k/-diameter of connection networks
Authors: Y. Dinitz, T. Eilam, S. Moran, S. Zaks
Venue: Proceedings of the Fifth Israel Symposium on the Theory of Computing Systems (ISTCS '97) (1997)

We study connection networks in which certain pairs of nodes have to be connected by k edge-disjoint paths, and study bounds for the minimal sum of lengths of such k paths. We define the related notions of total/sub k/-distance for a pair of nodes and total/sub k/-diameter of a connection network, and study the value TD/sub k/(d) which is the maximal such total/sub k/-diameter of a network with diameter d. These notions have applications in fault-tolerant routing problems, in ATM networks, and in compact routing in networks. We prove an upper bound on TD/sub k/(d) and a lower bound on the growth of TD/sub k/(d) as functions of k and d; those bounds are tight, /spl theta/(d/sup k/), when k is fired. Specifically, we prove that TD/sub k/(d)/spl les/2/sup k-1/d/sup k/, with the exceptions TD/sub 2/(1)=3, TD/sub 3/(1)=5, and that for every k, d/sub 0/>0, there exists (a) an integer d/spl ges/d/sub 0/ such that TD/sub k/(d)/spl ges/d/sup k/k/sup k/; and (b) a k-connected simple graph G with diameter d such that d/spl ges/d/sub 0/, and td/sub k/(G)/spl ges/(d-2)/sup k//k/sup k/.
A sizing measure for adaptive maintenance work products
Authors: A. Abran, M. Maya
Venue: Proceedings of the International Conference on Software Maintenance (1995)

A requirement for productivity models and productivity analysis is the ability to define a sizing technique of the product of a work process. There is currently a lack of measurement techniques for sizing the work product of software maintenance activities. This paper reports on research work carried out to define a sizing technique for the work product of the maintenance activities of the adaptive category. The proposed sizing technique is based on an extension to the Function Points technique which has been designed to measure the functional size of software applications from a user's perspective. However, it has been used mostly to measure either medium or large development or enhancement projects. An extended version of Function Points is proposed to take into account a finer level of granularity congruent with the small maintenance work products. This extension provides the ability to adequately size products that would have been previously bundled within the same size interval when using the conventional technique. This extension was field tested in an organization over a four-year period and preliminary results are discussed.
Little languages: little maintenance?
Authors: Arie Deursen, Paul Klint
Venue:  (1997)

So-called little, or domain-specific languages (DSLs), have the potential to make software maintenance simpler: domain-experts can directly use the DSL to make required routine modifications. At the negative side, however, more substantial changes may become more difficult: such changes may involve altering the domain-specific language. This will require compiler technology knowledge, which not every commercial enterprise has easily available. Based on experience taken from industrial practice, we discuss the role of DSLs in software maintenance, the dangers introduced by using them, and techniques for controlling the risks involved.
Blocking for External Graph Searching
Authors: Mark H. Nodine, Michael T. Goodrich, Jeffrey S Vitter
Venue:  (1992)

In this paper we consider the problem of using disk blocks efficiently in searching graphs that are too large to fit in internal memory. Our model allows a vertex to be represented any number of times on the disk in order to take advantage of redundancy. We give matching upper and lower bounds for complete d-ary trees and d-dimensional grid graphs, as well as for classes of general graphs that intuitively speaking have a close to uniform number of neighbors around each vertex.
Smart Business
Authors: Dave L. Chapman, Barry Sheehy
Venue:  (2002)

:Technology investment is the fastest-rising issue on corporate agendas. In Smart Business, Dave Chapman and Barry Sheehy reveal how to reduce the risks inherent in information technology investments by identifying the right questions to ask. Smart Business provides answers to managers who wonder why they spend so much money on information technology without receiving commensurate payoffs. This book also delivers immense value to all concerned with reducing risk, creating economic value, and achieving real breakthroughs in technology investment.
Dynamic Adaptive File Management in a Local Area Network
Authors: Jiong Yang, Wei Wang, Richard Muntz, Silvia Nittel
Venue: Proceedings of the The 20th International Conference on Distributed Computing Systems ( ICDCS 2000) (2000)

In light of advances in processor and networking technology, especially the emergence of network attached disks; the traditional client-server architecture of file systems has become sub-optimal for many computation/data intensive applications. In this paper, we introduce a revised architecture for file management employing network-attached storage: the dynamic file server environment (Dynamo). Dynamo introduces two main architectural innovations: (1) To provide high scalability, the clients mainly perform the file management functions cooperatively in the system. Furthermore, data is transferred directly to the client's cache from network-attached disks, thus avoiding copies from a disk to the server buffer and then over the network to the client. (2) Dynamo uses a cooperative cache management, which employs a decentralized lottery-based page re-placement strategy. We show via performance benchmarks run on the Dynamo system and simulation results how this architecture increases the system's adaptability, scalability and cost performance.
Note on the GI/GI/1 queue with LCFS-PR observed at arbitrary times
Authors: Rudesindo N\''{u}\~{n}ez Queija
Venue:  (2000)

Consider the GI/GI/1 queue with the Last-Come First-Served Preemptive-Resume service discipline. We give intuitive explanations for (i) the geometric nature of the stationary queue length distribution and (ii) the mutual independence of the residual service requirements of the customers in the queue, both considered at arbitrary time points. These distributions have previously been established in the literature by either first considering the system at arrival instants or using balance equations. Our direct arguments provide further understanding of (i) and (ii).
Pipelined Asynchronous Circuits
Authors: Andrew M Lines
Venue:  (1998)

This thesis presents a design style for implementing communicating sequential processes (CSP) as quasi delay insensitive asynchronous circuits, based on the compilation method of [1]. Although hand compilation can always yield optimal circuits to a good designer, a restricted approach is suggested which can easily implement circuits with some slack between inputs and outputs. These circuits are fast and versatile building blocks for highly pipelined designs. The first chapter presents the implementation approach for individual cells. The second chapter investigates the time behavior of complex pipelined circuits, with the goal of adding slack where necessary and adjusting transistor sizes to optimize the overall throughput.
Using Multiple Feedback Loops for Object Profiling, Scheduling and Migration in Soft Real-Time Distributed Object Systems
Authors: V. Kalogeraki, P. M. Melliar-Smith, L. E. Moser
Venue: Proceedings of the 2nd IEEE International Symposium on Object-Oriented Real-Time Distributed Computing (1999)

Complex soft real-time distributed object systems require object profiling, scheduling and migration algorithms to respond to transient changes in the load or in the availability of the resources. We have developed a Resource Management System for a soft real-time distributed object system that is based on a three-level feedback loop which employs a profiling algorithm that monitors the usage of the resources, a least laxity scheduling algorithm that schedules the tasks, and hot spot and cooling algorithms that allocate and migrate objects to balance the load on the resources. The Resource Management System consists of a single (but possibly replicated and distributed) Resource Manager, and Profilers and Schedulers located on each of the processors in the distributed system.
Deadlock prevention by acyclic orientations
Authors: Jean-Claude Bermond, Miriam Di Ianni, Michele Flammini, Stéphane Pérennès
Venue: Discrete Applied Mathematics (2003)

Deadlock prevention for routing messages has a central role in communication networks, since it directly influences the correctness of parallel and distributed systems. In this paper, we extend some of the computational results presented in Second Colloquium on Structural Information and Communication Complexity (SIROCCO), Carleton University Press, 1995, pp. 1-12 on acyclic orientations for the determination of optimal deadlock-free routing schemes. In this context, minimizing the number of buffers needed to prevent deadlocks for a set of communication requests is related to finding an acyclic orientation of the network which minimizes the maximum number of changes of orientations on the dipaths realizing the communication requests. The corresponding value is called the rank of the set of dipaths.We first show that the problem of minimizing the rank is NP-hard if all shortest paths between the couples of nodes wishing to communicate have to be represented and even not approximable if only one shortest path between each couple has to be represented. This last result holds even if we allow an error which is any sublinear function in the number of couples to be connected.We then improve some of the known lower and upper bounds on the rank of all possible shortest dipaths between any couple of vertices for particular topologies, such as grids and hypercubes, and we find tight results for tori.