ppxscal/embedding_network huggingface dataset:
Failure recovery for structured P2P networks: protocol design and performance evaluation
Authors: Simon S. Lam, Huaiyu Liu
Venue: ACM SIGMETRICS Performance Evaluation Review (2004)

Measurement studies indicate a high rate of node dynamics in p2p systems. In this paper, we address the question of how high a rate of node dynamics can be supported by structured p2p networks. We confine our study to the hypercube routing scheme used by several structured p2p systems. To improve system robustness and facilitate failure recovery, we introduce the property of K-consistency, K ≥ 1, which generalizes consistency defined previously. (Consistency guarantees connectivity from any node to any other node.) We design and evaluate a failure recovery protocol based upon local information for K-consistent networks. The failure recovery protocol is then integrated with a join protocol that has been proved to construct K-consistent neighbor tables for concurrent joins. The integrated protocols were evaluated by a set of simulation experiments in which nodes joined a 2000-node network and nodes (both old and new) were randomly selected to fail concurrently over 10,000 seconds of simulated time. In each such "churn" experiment, we took a "snapshot" of neighbor tables in the network once every 50 seconds and evaluated connectivity and consistency measures over time as a function of the churn rate, timeout value in failure recovery, and K. Storage and communication overheads were also evaluated. We found our protocols to be effective, efficient, and stable for an average node lifetime as low as 8.3 minutes (the median lifetime measured for Napster and Gnutella was 60 minutes [10]).
New hardness results for congestion minimization and machine scheduling
Authors: Julia Chuzhoy, Joseph (Seffi) Naor
Venue: Proceedings of the thirty-sixth annual ACM symposium on Theory of computing (2004)

We study the approximability of two natural NP-hard problems. The first problem is congestion minimization in directed networks. We are given a directed capacitated graph and a set of source-sink pairs. The goal is to route all pairs with minimum congestion on the network edges. A special well-studied case of this problem is the edge-disjoint paths problem, where all edges have unit capacities. The second problem is discrete machine scheduling, where we are given a set of jobs, and for each job a list of intervals in which it can be scheduled. The goal is to find the smallest number of machines on which all jobs can be scheduled, such that no two jobs assigned to the same machine overlap. Both problems are known to be O(log n/log log n)-approximable via the randomized rounding technique of Raghavan and Thompson. However, until recently, only a Max SNP hardness was known for each problem. We make some progress in closing this gap by showing that both problem are Ω(log log n)-hard to approximate unless NP ⊆ DTIME(nO(log log log n)). Our hardness proof for congestion minimization holds even for the special case of the edge-disjoint paths problem.
Spectral gradients for color-based object recognition and indexing
Authors: Daniel Berwick, Sang Wook Lee
Venue: Computer Vision and Image Understanding (2004)

In the past decade color has been developed as an effective cue for object recognition and image indexing. The initial draw of color was how easily object signatures could be captured and compared. Simple histograms of colors radiated from an object proved to be a stable representation of many objects without requiring complex geometric processing to address object pose. While recognition/indexing should depend only on colors intrinsic to object reflectance, a color signature computed from raw image colors is highly sensitive to the color and pose (direction) of incident illumination. Several methods have explored illumination-color invariants, and most of the recent invariants to illumination color and pose employ some form of chromacity representations based on the ratios of image color values or their combinations. This paper presents a comprehensive framework for logarithmic chromacities for the interpretation of image color change due to illumination pose and color. A log-chromacity space is developed from spectral (color) derivatives of logarithmic image irradiance, called Spectral gradients, to achieve invariance to global illumination color and pose. In this space, the multiplicative influence of illumination color and pose on image irradiance become additive effects, and this facilitates the analysis of illumination color and pose. A representation from spatial derivatives of spectral gradients, called spectral-spatial gradients is also developed to additionally provide invariance to local variation of illumination color within an image. Experimental results are presented to demonstrate the efficacy of the proposed descriptors.
The Intelligent Transportation System and the Ethics of Intelligent Computers
Authors: James Wentworth
Venue: ACM SIGCAS Computers and Society (2003)

Machines that think are already here. This was demonstrated in May of 1997 when IBMs Deep Blue defeated Gary Kasparov (grandmaster and world champion chess player) in a well publicized chess match. Sometime between 2020 and 2040 intelligent machines will match or surpass humans in learning, thinking and reasoning, and will have the consciousness and emotions critical to setting or changing their goals. These intelligent machines will most likely also be an integral component of the future ITS. How much free will and level of abstraction (to explore their world and cyberspace and to learn) will these intelligent machines have and who will decide? In scientific fields it often takes a disaster for the practitioners to address fundamental problems, like stress corrosion in suspension bridge eyebar links. Intelligent machines have the potential capacity for artificial evil (to do harm) indicating that the morals and ethics of intelligent machines should be considered prior to their field implementation. What does this all mean for the distant future of ITS? 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
Elastoplastic Torsion: Twist and Stress
Authors: Dianne P. O'Leary
Venue: Computing in Science and Engineering (2004)

Consider a long rod made of metal, plastic, rubber, or some other homogeneous material. Hold the rod at the ends and twist one end clockwise and the other end counterclockwise. This torsion (twisting) causes stresses in the rod. If the force we apply is small enough, the rod behaves as an elastic body: when we release it, it will return to its original state. But if we apply a lot of twisting force, we will eventually change the rod's structure: some portion of it will behave plastically and will be permanently changed. If the whole rod behaves elastically, or if it all behaves plastically, then modeling is rather easy. More difficult cases occur when there is a mixture of elastic and plastic behavior. Here, we'll investigate the rod's behavior over a full range of torsion.
A superlinearly convergent predictor-corrector method for degenerate LCP in a wide neighborhood of the central path with *-iteration complexity
Authors: Florian A. Potra
Venue: Mathematical Programming: Series A and B (2004)

An interior point method for monotone linear complementarity problems acting in a wide neighborhood of the central path is presented. The method has *-iteration complexity and is superlinearly convergent even when the problem does not possess a strictly complementary solution.
System-Level Power Optimization
Authors: Wolfgang Nebel
Venue: Proceedings of the Digital System Design, EUROMICRO Systems (2004)

More features and higher bandwidth needed for new mobile services consume more power than battery technology can provide. Higher performance in information processing produces more heat than cooling technology can dissipate. These trends require power aware design methodologies throughout the entire design. The largest impact on the power consumption can be achieved at the system level where the algorithms and the system architecture are defined. In this contribution we present a System-Level design flow and respective EDA support tools for low power designs. We analyze the requirements for such a design technology, which shifts more responsibility to the system architect. We exemplify this approach with a design flow for low power systems. The architecture of a power estimation tool is presented, which is capable to guide the designer in system level and architecture level decisions in the pre-implementation phase. The effectiveness of the approach is demonstrated through some use cases.
Active learning for automatic classification of software behavior
Authors: James F. Bowring, James M. Rehg, Mary Jean Harrold
Venue: ACM SIGSOFT Software Engineering Notes (2004)

A program's behavior is ultimately the collection of all its executions. This collection is diverse, unpredictable, and generally unbounded. Thus it is especially suited to statistical analysis and machine learning techniques. The primary focus of this paper is on the automatic classification of program behavior using execution data. Prior work on classifiers for software engineering adopts a classical batch-learning approach. In contrast, we explore an active-learning paradigm for behavior classification. In active learning, the classifier is trained incrementally on a series of labeled data elements. Secondly, we explore the thesis that certain features of program behavior are stochastic processes that exhibit the Markov property, and that the resultant Markov models of individual program executions can be automatically clustered into effective predictors of program behavior. We present a technique that models program executions as Markov models, and a clustering method for Markov models that aggregates multiple program executions into effective behavior classifiers. We evaluate an application of active learning to the efficient refinement of our classifiers by conducting three empirical studies that explore a scenario illustrating automated test plan augmentation.
Demand Flow Network
Authors: Linyan Sun, Bo Liu, Xiting Wu
Venue: Proceedings of the E-Commerce Technology for Dynamic E-Business, IEEE International Conference (2004)

This paper had brought up the conceptual model of Demand Flow Network (DFN) on the basis of supply chains theories. The DFN Model, DFN Value Model and DFN Core Competency Model had also been established and analyzed separately in accordance with related theory. The application of DFN theory also had been studied.
ASCI Application Performance and the Impact of Commodity Processor Architectural Trends
Venue: Proceedings of the 1998 International Workshop on Innovative Architecture (1998)

The purpose of this paper is to summarize recent performance results from an important ASCI-related application and to speculate on how trends within the computer industry and in computer architecture relate to these results. 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
Managing Quality-of-Control Performance Under Overload Conditions
Authors: Giorgio Buttazzo, Manel Velasco, Pau Marti, Gerhard Fohler
Venue: Proceedings of the 16th Euromicro Conference on Real-Time Systems (2004)

A common method for dealing with overload conditionsin periodic task systems is to reduce the load by enlargingactivation periods. When a periodic task implementsa digital controller, however, the variation appliedon the task period also affects the control law, whichneeds to be recomputed for the new activation rate. Ifcomputing a new control law requires too much time tobe performed at runtime, a set of controllers has to bedesigned off line for different rates and the system hasto switch to the proper controller in the presence of anoverload condition. In this paper, we present a methodfor reducing the number of controllers to be designedoff line, while still guaranteeing a given control performance.The proposed approach has been integrated withthe elastic scheduling theory to promptly react to overloadconditions. The effectiveness of the proposed approachhas been verified through extensive simulationexperiments performed on an inverted pendulum.
Microarchitecture Optimizations for Exploiting Memory-Level Parallelism
Authors: Yuan Chou, Brian Fahs, Santosh Abraham
Venue: ACM SIGARCH Computer Architecture News (2004)

The performance of memory-bound commercial applicationssuch as databases is limited by increasing memory latencies. Inthis paper, we show that exploiting memory-level parallelism(MLP) is an effective approach for improving the performance ofthese applications and that microarchitecture has a profound impacton achievable MLP. Using the epoch model of MLP, we reasonhow traditional microarchitecture features such as out-of-orderissue and state-of-the-art microarchitecture techniques suchas runahead execution affect MLP. Simulation results show that amoderately aggressive out-of-order issue processor improvesMLP over an in-order issue processor by 12-30%, and that aggressivehandling of loads, branches and serializing instructionsis needed to attain the full benefits of large out-of-order instructionwindows. The results also show that a processor's issue windowand reorder buffer should be decoupled to exploit MLP more efficiently.In addition, we demonstrate that runahead execution ishighly effective in enhancing MLP, potentially improving the MLPof the database workload by 82% and its overall performance by60%. Finally, our limit study shows that there is considerableheadroom in improving MLP and overall performance by implementingeffective instruction prefetching, more accurate branchprediction and better value prediction in addition to runahead execution.
An Efficient Algorithm to Compute Differences between Structured Documents
Authors: Kyong-Ho Lee, Yoon-Chul Choy, Sung-Bae Cho
Venue: IEEE Transactions on Knowledge and Data Engineering (2004)

SGML/XML are having a profound impact on data modeling and processing. This paper presents an efficient algorithm to compute differences between old and new versions of an SGML/XML document. The difference between the two versions can be considered to be an edit script that transforms one document tree into another. The proposed algorithm is based on a hybridization of bottom-up and top-down methods: The matching relationships between nodes in the two versions are produced in a bottom-up manner and then the top-down breadth-first search computes an edit script. Faster matching is achieved because the algorithm does not need to investigate the possible existence of matchings for all nodes. Furthermore, it can detect structurally meaningful changes such as the movement and copy of a subtree as well as simple changes to the node itself like insertion, deletion, and update.
The controlled estimation method in the multiobjective linear fractional problem
Authors: R. Caballero, M. Hernández
Venue: Computers and Operations Research (2004)

This paper introduces a new method to estimate the weakly efficient set for the Multiobjective Linear Fractional Programming problem. The main idea is based on the procedure proposed by Tzeng and Hsu (In: G.H. Tzeng, H.F. Wang, U.P. Wen, L. Yu (Eds.), Multiple Criteria Decision Making, Springer, New York, 1994, pp. 459-470), called CONNISE, However, as we will explain in this paper, the CONNISE method is not always convergent for problems with more than two objectives. For this reason, we have developed a new method, called "The Controlled Estimation Method", based on the same concept as CONNISE regarding the decision-maker being able to control distances between points from the estimation set he/she wants to find, while ensuring the method is convergent with problems with more than two objectives. Thus, we propose an algorithm able to calculate a discrete estimation of the weakly efficient set that verifies this property of the CONNISE method, but further, improves it thanks to its convergence and the fact that it satisfies the three good properties suggested by Sayin (Math. Programming 87(3) (2000) 543): Coverage, Uniformity, and Cardinality.
How Higher-Education Systems Influence Software Engineering Degree Programs
Authors: Oscar Dieste, Natalia Juristo, Ana M. Moreno
Venue: IEEE Software (2004)

Undergraduate programs that cover knowledge related to software engineering range from software engineering-specific programs to traditional computer science programs, which might teach some subjects related to software engineering. Software engineering-specific programs have proliferated in countries such as the US, Australia, and the UK. However, this isn't the case in continental Europe. This difference is due largely to the organization of the higher-education systems in those countries. Organizational factors responsible for this difference include the type of accreditation system and whether the government or the higher-education institution defines the syllabus.
Gone with the wind in sixty seconds
Venue: ACM SIGGRAPH 2003 video review on Animation theater program: part 2 - Volume 146 (2003)

The plot of the Hollywood epic Gone With The Wind" is compressed to one minute, with hilarious results in this short student film. Copyright held by creator. 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
Finding the Sink Takes Some Time: An Almost Quadratic Lower Bound for Finding the Sink of Unique Sink Oriented Cubes
Authors: Ingo Schurr, Tibor Szab&#x00f3;
Venue: Discrete Computational Geometry (2004)

We give a worst-case &#x03a9;(n2/log n) lower bound on the number of vertex evaluations a deterministic algorithm needs to perform in order to find the (unique) sink of a unique sink oriented n-dimensional cube. We consider the problem in the vertex-oracle model, introduced in [18]. In this model one can access the orientation implicitly, in each vertex evaluation an oracle discloses the orientation of the edges incident to the queried vertex. An important feature of the model is that the access is indeed arbitrary, the algorithm does not have to proceed on a directed path in a simplex-like fashion, but could &#x201c;jump around&#x201d;. Our result is the first superlinear lower bound on the problem. The strategy we describe works even for acyclic orientations. We also give improved lower bounds for small values of n and fast algorithms in a couple of important special classes of orientations to demonstrate the difficulty of the lower bound problem.
Extracting mathematical expressions from postscript documents
Authors: Michael Yang, Richard Fateman
Venue: Proceedings of the 2004 international symposium on Symbolic and algebraic computation (2004)

Full-text indexing of documents containing mathematics cannot be considered a complete success unless the mathematics symbolism is extracted and represented in a standardized form permitting both searching for formulas, and re-use of this information in (for example) computer algebra systems. Most documents produced in the past and subsequently digitally encoded, and even most of those potentially "born digital" in current journal production are---at best---encoded in a printer form such as Adobe Postscript [1], in which mathematics is not explicitly marked or easily identifiable. While one might look forward in the future to other document encodings such as MathML, the common journal or textbook product is essentially without semantic content: a jumble of odd characters. Sometimes it is just a jumble of black and white dots! In this paper we demonstrate an approach to decoding, to recognizing and extracting mathematical expressions, from a Postscript document. We can produce a syntactic representation of the extracted expressions which can then be used to generate various forms. For example, if we extract TeX or Presentation MathML, we can re-typeset the expression, but perhaps in a different size or font family. More significantly, if we start from this presentation information, we can hope to combine it with additional contextual processing of the surrounding text and meta-data associated with the document, to assign semantics,(e.g. content MathML), or provide versions in computer algebra system languages such as Maple or Mathematica. Finally, it is possible to use this material to present audio or braille versions of mathematics for the visually disabled. We have previously addressed some aspects of the higher level of processing (parsing TeX for example). In this paper we address the only first stage and concentrate on what may seem to be overly simple, but is in fact difficult to do precisely: extracting the mathematics parts from text.
Behavioral modeling and simulation of mixed-signal system-on-a-chip using SystemC
Authors: Johnny Bjørnsen, Thomas E. Bonnerud, Trond Ytterdal
Venue: Analog Integrated Circuits and Signal Processing (2003)

We describe an efficient software framework for rapid behavioral modeling and simulation of mixed-signal System-on-a-Chip (SoC). The framework is based on the SystemC C++ class libraries and has been proven to be a very effective tool for exploring different system-level architectures in the early stages of the design process. We also present the results of three case studies where we have used the framework: a 10-bit, 60 Mega-sample/s pipelined ADC, 14-bit, 100 Mega-sample/s pipelined ADC with background calibration, and a CMOS camera-on-a-chip.
Agent-Based Model of Flow in the Urethra
Authors: Ian R. Greenshields
Venue: Proceedings of the 17th IEEE Symposium on Computer-Based Medical Systems (2004)

This short paper describes ongoing work which is an extension of earlier work exploringow models in elastic deformable tubes. In this paper we describe an application of SmoothedParticle Hydrodynamics (SPH) married to the earlier model implemented in an agent-basedplatform.
Structural Evolution of an Open Source System: A Case Study
Venue: Proceedings of the 12th IEEE International Workshop on Program Comprehension (2004)

Software evolution empirical studies are madepossible only when data is available and easilycollectable. Open Source software provides a goodopportunity for observing software products in variousphases of their evolution, growth and maturity.One of the aspects that have not been analyzed yetthrough empirical studies is the relation that existsbetween code components growth and the evolving codestructure. In this paper we look at the growth of codeelements by measuring the total number of files perrelease and also by visualizing the folder structure as atree. Both, the number of files and the shape of the foldertree structure offer proxies to study the evolvingcomplexity of the system. In this study, a number ofhypotheses about the evolutionary patterns in the size offiles and folders, in the folder tree structure, reflectingcommon assumptions on software engineering and OpenSource are tested against empirical data reflecting theevolution of the ARLA system. We also relate some of theobserved patterns to the arrival rate of new developers.Results show that the number of code components(files and folders) over releases can be interpreted as alinear trend with a superimposed ripple. We alsodescribe the more apparent characteristics of theevolution of the folder tree structure. Furthermore, weobserve that the average size of files and folders tends tostabilize over releases. The cumulative number of peoplewho have been involved as developers of the systemfollows a trend which resembles that of the size in filesover releases, suggesting that the latter could provide agood indicator for rate of work and productivity. Therewas no apparent relation between the arrival rate ofdevelopers and the changes observed in the codestructure.