ppxscal/embedding_network huggingface dataset:
Distributed algorithms for finding and maintaining a k-tree core in a dynamic network
Authors: Saurabh Srivastava, R. K. Ghosh
Venue: Information Processing Letters (2003)

A k-core Ck of a tree T is subtree with exactly k leaves for k ≤ nl, where nl the number of leaves in T, and minimizes the sum of the distances of all nodes from Ck. In this paper first we propose a distributed algorithm for constructing a rooted spanning tree of a dynamic graph such that root of the tree is located near the center of the graph. Then we provide a distributed algorithm for finding k-core of that spanning tree. The spanning tree is constructed in two stages. In the first stage, a forest of trees is generated. In the next stage these trees are connected to form a single rooted tree. An interesting aspect of the first stage of proposed spanning algorithm is that it implicitly constructs the (convex) hull of those nodes which are not already included in the spanning forest. The process is repeated till all non root nodes of the graph have chosen a unique parent. We implemented the algorithms for finding spanning tree and its k-core. A core can be quite useful for routing messages in a dynamic network consisting of a set of mobile devices.
An Iterative Scheme for Maximum Likelihood Estimation in Software Reliability Modeling
Authors: Hiroyuki Okamura, Yasuhiro Watanabe, Tadashi Dohi
Venue: Proceedings of the 14th International Symposium on Software Reliability Engineering (2003)

This paper focuses on an estimation problem of modelparameters in software reliability modeling. We introducethe EM (expectation-maximization) algorithms for softwarereliability models and compare them with the classical parameterestimation methods. Especially, we extensively developthe EM algorithms for two cases; (i) the time intervaldata of software fault detection are available, (ii) additivesoftware reliability models based on non-homogeneousPoisson processes are used. In numerical examples, wecompare the iterative schemes based on the EM algorithmswith classical methods such as the Newton's method and theFisher's scoring method and show that the EM algorithmsare attractive in terms of convergence property.
CNB: a critical-network-based timing optimization method for standard cell global routing
Authors: XianLong Hong, Tong Jing, JingYu Xu, HaiYun Bao, Jun Gu
Venue: Journal of Computer Science and Technology (2003)

A novel method, named critical-network-based (CNB), for timing optimization in global routing is presented in this paper. The essence of this method is different from that of the typical existing ones, named nets-based (NB) and critical-path-based (CPB). The main contribution of this paper is that the CNB delay reduction method is more efficient than the typical existing ones. This new method makes it possible to reduce the delay in an overall survey. Based on CNB, a timing optimization algorithm for global routing is implemented and tested on Microelectronics Center of North Carolina (MCNC) benchmarks in this paper. The experimental results are compared between this algorithm and the existing ones. The experimental results show that this algorithm is able to control the delay efficiently.
On the automated implementation of modal logics used to verify security protocols
Authors: Tom Coffey, Reiner Dojen, Tomas Flanagan
Venue: Proceedings of the 1st international symposium on Information and communication technologies (2003)

Formal verification provides a rigid and thorough means of evaluating the correctness of cryptographic protocols so that even subtle defects can be identified. As the application of formal techniques is highly involved, software has been developed in order to facilitate protocol verification. Protocol weaknesses or flaws can thus be identified and corrected during the design process. In this paper the verification process is illustrated by analysing the ASK protocol using the tool AAPA2. The virtues and limitations of the tool are discussed. Overall, the analysis shows that the use of automated tools in verifying security protocols offers significant advantages to the protocol designer.
A type system for well-founded recursion
Authors: Derek Dreyer
Venue: Proceedings of the 31st ACM SIGPLAN-SIGACT symposium on Principles of programming languages (2004)

In the interest of designing a recursive module extension to ML that is as simple and general as possible, we propose a novel type system for general recursion over effectful expressions. The presence of effects seems to necessitate a backpatching semantics for recursion similar to that of Scheme. Our type system ensures statically that recursion is well-founded---that the body of a recursive expression will evaluate without attempting to access the undefined recursive variable---which avoids some unnecessary run-time costs associated with backpatching. To ensure well-founded recursion in the presence of multiple recursive variables and separate compilation, we track the usage of individual recursive variables, represented statically by "names". So that our type system may eventually be integrated smoothly into ML's, reasoning involving names is only required inside code that uses our recursive construct and need not infect existing ML code, although instrumentation of some existing code can help to improve the precision of our type system.
Microsoft's Compact Framework Targets Smart Devices
Authors: Alexander Wolfe
Venue: Queue (2003)

Welcome to my first installment of ACM Queue’s ToolKit column. Each issue I’ll dig beneath the market-friendly, feature-rich exterior of some of the best-known (and some of the least-known) development tools in an attempt to separate the core app from the product spec sheet.
Power-driven Design of Router Microarchitectures in On-chip Networks
Authors: Hangsheng Wang, Li-Shiuan Peh, Sharad Malik
Venue: Proceedings of the 36th annual IEEE/ACM International Symposium on Microarchitecture (2003)

As demand for bandwidth increases in systems-on-a-chipand chip multiprocessors, networks are fast replacing busesand dedicated wires as the pervasive interconnect fabric foron-chip communication. The tight delay requirements facedby on-chip networks have resulted in prior microarchitecturesbeing largely performance-driven. While performanceis a critical metric, on-chip networks are also extremelypower-constrained. In this paper, we investigate on-chipnetwork microarchitectures from a power-driven perspective.We first analyze the power dissipation of existing networkmicroarchitectures, highlighting insights that promptus to devise several power-efficient network microarchitectures:segmented crossbar, cut-through crossbar and write-throughbuffer. We also study and uncover the power savingpotential of an existing network architecture: expresscube. These techniques are evaluated with synthetic as wellas real chip multiprocessor traces, showing a reduction innetwork power of up to 44.9%, along with no degradationin network performance, and even improved latency-throughputin some cases.
Gate Sizing and Buffer Insertion using Economic Models for Power Optimization
Authors: Ashok K. Murugavel, N. Ranganathan
Venue: Proceedings of the 17th International Conference on VLSI Design (2004)

In this paper, we propose new algorithms for gatesizing and buffer insertion that aim at reducing the switchedcapacitance in gate level circuits. We have formulated the gatesizing and the buffer insertion problems as competitive resourceallocation based auction theoretic games and develop solutionsbased on the Nash equilibrium function. The main contributionof this work is in the application of economic models andgame theoretic solutions to logic synthesis problems for poweroptimization. The gate sizing problem is modeled as a ProgressiveSecond Price (PSP) auction, where the players of the auction(representing the gates) bid for partial delays in each path ofthe circuit. The PSP auction process attempts to optimize thepower consumption of each path in the circuit. The bids suppliedby the players are used to determine the allocation for eachplayer in the auction, using a game theoretic formulation. Thesize of a gate is determined based on its delay allocation. The gatesizing problem can be integrated with buffer insertion for betterpower optimization and we develop a game theoretic algorithmfor combined gate sizing and buffer insertion. Experimentalresults on MCNC '91 benchmark circuits indicate that theproposed algorithms provide better power optimization thansimilar approaches in the literature, and are comparable in termsof run times.
From users to consumers
Authors: Bo Dahlbom
Venue: Scandinavian Journal of Information Systems (2003)

The perspective on technology of the Scandinavian approach was the perspective of a work oriented society. And work was mainly factory work, the production of goods. The world is different now with most everyone employed in services and a growing consumer market. We can look forward to a forceful wave of industrialization of services-using information technology to automate, standardize, and package services. A professional systems developer will again be faced with the challenge of achieving nonoppressive automation. A new agenda for action research will have to be developed, new large scale projects with trade unions and public agencies are waiting to be initiated, involving both users of information technology and, more important, consumers as well, in a consumer oriented approach to services.
Maximum likelihood and conditional maximum likelihood learning algorithms for hidden Markov models with labeled data: application to transmembrane protein topology prediction
Authors: P. G. Bagos, TH. D. Liakopoulos, S. J. Hamodrakas
Venue: Proceedings of the international conference on Computational methods in sciences and engineering (2003)

Hidden Markov Models (HMMs) have been widely used in applications in computational biology, during the last few years. In this paper we are reviewing the main algorithms proposed in the literature for training and decoding a HMM with labeled sequences, in the context of the topology prediction of bacterial integral membrane proteins. We evaluate the Maximum Likelihood algorithms traditionally used for the training of a Hidden Markov Model, against the less commonly used Conditional Maximum Likelihood-based algorithms and, after combining results previously obtained in the literature, we propose a new variant for Maximum Likelihood training. We compare the convergence rates of each algorithm showing the advantages and disadvantages of each method in the context of the problem at hand. Finally, we evaluate the predictive performance of each approach, using state of the art algorithms proposed for Hidden Markov Model decoding and mention the appropriateness of each one.
Eliciting coordination policies from requirements
Authors: Henry Muccini, Fabio Mancinelli
Venue: Proceedings of the 2003 ACM symposium on Applied computing (2003)

Software coordination models and languages describe how agents, resources and processes work together to implement a software system. One of their limitations is that they are used late in the software development and they are not integrated in a typical software development process.What we claim, with our research, is that if coordination becomes explicit and formalized as soon as possible in the life cycle, then it is possible to create coordinated-aware software systems. Moreover, it is possible to verify the adequacy of a Software Architecture model (or of the code itself) with respect to these dynamic constraints as well as refine or disambiguate coordination requirements themselves.In previous work, we presented a UML-based development process to elicit, describe, analyze and validate system coordination properties that might be then specified with a suitable coordination language. In this general picture, the aim of this paper is to implement the first step, i.e., to elicit and formalize coordination policies. We propose a five steps approach that incrementally identifies the elements to be coordinated (i.e., static coordination) and how these entities may be coordinated (i.e., dynamic coordination).
Hysteresis loop of a nanoscopic magnetic array
Authors: A. Kaczanowski, K. Malarz, K. Kulakowski
Venue: Proceedings of the international conference on Computational methods in sciences and engineering (2003)

Dynamics of nanoscopic arrays of monodomain magnetic elements is simulated by means of the Pardavi-Horvath algorithm. Experimental hysteresis loop is reproduced for the arrays of Ni, with period 100 nm and the mean coercive field 710 Oe. We investigate the fractal character of the cluster of elements with positive magnetic moments. No fractal is found. We apply also the technique of damage spreading. The consequences of a local flip of a magnetic element remain limited to a finite area. We conclude that the system does not show a complex behaviour.
Union of shadows
Authors: Béla Bollobás, Imre Leader
Venue: Theoretical Computer Science (2003)

Our aim in this note is to show that if A is a family of (k 3) 3-sets then there are at least (k 4) 4-sets that may be written as unions of two 2-sets in the shadow of A. This is the first non-trivial case of a more general conjecture about unions of shadows.
Stochastic Analysis of Convergence via Dynamic Representation for a Class of Line-search Algorithms
Authors: L. Pronzato, H. P. Wynn, A. A. Zhigljavsky
Venue: Combinatorics, Probability and Computing (1997)

Certain convergent search algorithms can be turned into chaotic dynamic systems by renormalisation back to a standard region at each iteration. This allows the machinery of ergodic theory to be used for a new probabilistic analysis of their behaviour. Rates of convergence can be redefined in terms of various entropies and ergodic characteristics (Kolmogorov and R&eacute;nyi entropies and Lyapunov exponent). A special class of line-search algorithms, which contains the Golden-Section algorithm, is studied in detail. Their associated dynamic systems exhibit a Markov partition property, from which invariant measures and ergodic characteristics can be computed. A case is made that the R&eacute;nyi entropy is the most appropriate convergence criterion in this environment.
Testability analysis of hierarchical finite state machines
Authors: F. Martinolle, J. C. Geffroy, B. Soulas
Venue: Proceedings of the conference on European design automation (1991)

We present a hierarchical analysis of interconnected finite state machines helpful for testability evaluation. Formal operators determine the controllable and observable functional parts of the modules of the hierarchy; several kinds of functional redundancies are deduced and their causes are diagnosed. A prototype written in Prolog validates these concepts.
An implementation and empirical evaluation of the tasking facilities in ADA
Authors: Seif Haridi, John-Olof Bauner, Gert Svensson
Venue: ACM SIGPLAN Notices (1981)

An implementation of Ada's tasking facilities, on the LSI-11 microcomputer, is described.The performance and the size of the kernel are compared with those of another language having the same basic characteristics, but with a synchronization mechanism based on shared data.The execution of typical test examples shows that the time spent in the two kernels is more or less the same.
Design and Behavioral Modeling Tools for Optical Network-on-Chip
Authors: M. Brière, L. Carrel, T. Michalke, F. Mieyeville, I. O'Connor, F. Gaffiot
Venue: Proceedings of the conference on Design, automation and test in Europe - Volume 1 (2004)

In this paper, we present a tool to analyse photonic devices that can be used to realize basic building blocks of an optical network-on-chip (ONoC). Co-design between electrical tools and optical tools is possible. The VHDL-AMS language has been used to implement behavioral models of photonic devices. For low-level simulation, a gateway between an optical simulator, based on the finite elements method, and a typical EDA layout editor has been realized.
Research on scheduling algorithms in Web cluster servers
Authors: YingChun Lei, YiLi Gong, Song Zhang, GuoJie Li
Venue: Journal of Computer Science and Technology (2003)

This paper analyzes quantitatively the impact of the load balance scheduling algorithms and the locality scheduling algorithms on the performance of Web cluster servers, and brings forward the Adaptive_LARD algorithm. Compared with the representative LARD algorithm, the advantages of the Adaptive_LARD are that: (1) it adjusts load distribution among the back-ends through the idea of load balancing to avoid learning steps in the LARD algorithm and reinforce its adaptability; (2) by distinguishing between TCP connections accessing disks and those accessing cache memory, it can estimate the impact of different connections on the back-ends' load more precisely. Performance evaluations suggest that the proposed method outperforms the LARD algorithm by up to 14.7%.
A Conversation with Dan Dobberpuhl
Authors: David Ditzel
Venue: Queue (2003)

The computer industry has always been about power. The development of the microprocessors that power computers has been a relentless search for more power, higher speed, and better performance, usually in smaller and smaller packages. But when is enough enough?
Functionality Defense by Heterogeneity: A new paradigm for Securing Systems
Authors: Raj Sharman, H. R. Rao, Shambhu Upadhyaya, Partha Khot, Sumit Manocha, Saumitra Ganguly
Venue: Proceedings of the Proceedings of the 37th Annual Hawaii International Conference on System Sciences (HICSS'04) - Track 7 - Volume 7 (2004)

The human race has evolved and thrived despite perpetually being attacked by different kinds of viruses, infections, diseases, etc. The body's natural immune system and self healing mechanism as well as the assisted healing systems in human communities has played a major role in this accomplishment. This model has served as an inspiration for the development of a new paradigm for security that we have proposed in this paper. While most security systems focus on defense of a single machine or a cluster of machines we have taken a radically different approach to security. We look at defense of functionalities rather than systems in thetraditional sense. In this paper, we propose a new way to look at security called the functionality (such as e-mail server, web services server, etc) defense by heterogeneity. Further we present an analysis, architecture and an algorithm for defending functionality.
Self-maintaining web pages
Authors: M. Schrefl, M. Bernauer, E. Kapsammer, B. Pröll, W. Retschitzegger, T. Thalhammer
Venue: Information Systems (2003)

Data-intensive web-based information systems usually employ database systems to store the contents forming the basis for web page construction. Generating web pages on the fly, especially in peak times, can lead to severe performance problems. Thus, pre-generation of web pages has been suggested to be ready for prime time, allowing to reliably deliver several hundred pre-generated pages per second. Maintaining the consistency of these web pages with respect to changes within the database in an efficient way, however, represents a major challenge. This paper presents a novel approach for "self-maintaining" web pages that is, different to previous approaches, characterized by a simple (and thus, easy to maintain) database-to-web page mapping and very low page re-generation costs. This is achieved by utilizing fragmentation techniques from distributed databases, by allocating parameterized fragment classes to web page classes (rather than individual fragments to single web pages), and using the Extensible Markup Language (XML) as an intermediate layer between the database and the final web pages.
Computing raster images from grid picture grammars
Authors: Frank Drewes, Sigrid Ewert, Renate Klempien-Hinrichs, Hans-Jörg Kreowski
Venue: Journal of Automata, Languages and Combinatorics (2003)

While a 2-dimensional grid picture grammar may generate pictures (defined as subsets of the unit square) with arbitrarily small details, only a finite number of them can be made visible as raster images for any given raster. We present an algorithm based on bottom-up tree automata which computes the set of all raster images of the pictures generated by a given grid picture grammar.
Exploring the influence of rewards on attitudes towards knowledge sharing
Authors: Gee Woo Bock, Young-Gul Kim
Venue: Advanced topics in information resources management (2003)

This study theoretically examines and empirically tests factors expected to affect an individual's knowledge sharing attitudes, intention and behavior in an organizational context. The research model is constructed based on the economic exchange theory, the social exchange theory, the self-efficacy theory and the theory of reasoned action. Results from the field survey of 467 employees of four large and government-invested organizations show that 'anticipated reciprocal relationships' and 'perceived personal contribution to the organization' are the major determinants of the individual's attitudes towards knowledge sharing. 'Anticipated extrinsic rewards,' believed by many as the most important motivating factor for knowledge sharing, are not significantly related to the attitudes towards knowledge sharing. As expected, positive attitudes towards knowledge sharing are found to lead to a positive intention to share knowledge and, finally, to actual knowledge sharing behaviors.
Studying the Chaos of Code Development
Authors: Ahmed E. Hassan, Richard C. Holt
Venue: Proceedings of the 10th Working Conference on Reverse Engineering (2003)

As large software systems evolve, controlling their complexityis a major challenge for many companies, as they striveto deliver future releases on time and within budget. Severalsource code based metrics have been proposed to assist indetermining the complexity of code to help control developmentcosts and outcome.In this paper we offer a novel view on the problem of complexityin software. We present a complexity metric that isbased on the process followed by the developers to producethe code instead of on the code directly. We conjecture thata chaotic/complex development process negatively affect itsoutcome, the source code. We validate our hypothesis empiricallyusing data derived from the development processhistory of six large open source projects (three operatingsystems: NetBSD, FreeBSD, OpenBSD; a window manager:KDE; an office productivity suite: KOffice; and a databasemanagement system: Postgres).
News 2.0
Venue: Queue (2003)

The majority of U.S. banks are migrating their ATMs from IBM’s OS/2 to a stripped-down version of Windows. The obvious reason: IBM is ceasing support for OS/2 after 2004. But under the surface there might be something more interesting at play.
Set constraints for destructive array update optimization
Authors: Mitchell Wand, William D. Clinger
Venue: Journal of Functional Programming (2001)

Destructive array update optimization is critical for writing scientific codes in functional languages. We present set constraints for an interprocedural update optimization that runs in polynomial time. This is a multi-pass optimization, involving interprocedural flow analyses for aliasing and liveness. We characterize and prove the soundness of these analyses using small-step operational semantics. We also prove that any sound liveness analysis induces a correct program transformation.