ppxscal/embedding_network huggingface dataset:
National Web Library 2.0: Are national libraries ready for the new version?
Authors: Lars G. Svensson
Venue: Information Services and Use (2007)

Community building and community-generated content are central concepts in both Web 2.0 and Library 2.0. So far, the discussion and most of the activity in the library sphere have focused on public libraries (in the North American sense) and some academic libraries whereas e.g. national libraries have not been mentioned in this context. It can be argued, that whereas public and academic libraries serve a well-defined community (the local population or the university's students and faculty), this does not apply to national libraries. In this paper we will show that national libraries have already adopted some of the most important concepts of both Web 2.0 and Library 2.0 - but within their own specialised community and without using the Web.
On Requirements Visualization
Authors: Orlena C. Z. Gotel, Francis T. Marchese, Stephen J. Morris
Venue: Proceedings of the Second International Workshop on Requirements Engineering Visualization (2007)

This paper summarizes the typical objectives and process of visualization and highlights the primary areas in which visualization systems and artifacts have been used to support requirements engineering activities to date. The paper suggests that the field has yet to realize some of the benefits that can arise from a well designed and task-oriented information visualization, falling behind other areas of software engineering in which visualization has been used to better effect. By way of an exemplar, the paper proposes the need for a way to visualize the multi-dimensional nature of requirements to help bring about a shared and rapid comprehension on the health of a project's requirements, and so support various diagnostic activities and decision making tasks during software development. It examines how new ways to "see' the requirements could be developed, based on metaphor and mapping, provides some samples, and outlines a research agenda to explore a vision related to requirements sensing.
A New Dynamic Wavelength Assignment Scheme in Wavelength-Convertible WBS Networks
Authors: Ching-Fang Hsu, Fang-Sheng Lin, Ke-Kuan Hsu
Venue: Proceedings of the 22nd International Conference on Advanced Information Networking and Applications (2008)

In the paper, we study the wavelength assignment problem in waveband switching (WBS) networks, which is composed of multi-granular optical cross-connect (MG-OXCs) interconnected by fiber links. WBS networks with MG-OXCs can route traffic at multiple granularities at the same time; therefore, the complexity of switching fabrics can be efficiently reduced. Moreover, in order to relax the wavelength continuity constraint on lightpath establishments, each MG-OXC node is equipped with certain number of wavelength converters. Focusing on minimizing the extra port consumption and utilizing wavelength converters in an efficient manner, we propose a heuristic algorithm, named Least-Configuration with Bounded Conversion (LCBC), under the dynamic traffic environment. Simulation results show that our algorithm can achieve a considerable port saving and significant performance gain by a well-design cost function.
A Solution Framework on Fundamentals in Model Transformation
Authors: Yucong Duan, Kyo-Chul Kang, Yuqing Gu
Venue: Proceedings of the Seventh IEEE/ACIS International Conference on Computer and Information Science (icis 2008) (2008)

With the great achievements and successes in model transformations (MT), we propose to study MTs from an open and general cognitive background which differs from most current practice. Issues under study cover the broad scope of openness, incompleteness, uncertainty, quality management, human vs. machine aspects, etc, in the evolving process composed of MTs. A solution framework corresponding to some of these issues is proposed to help promote its use and deployment.
An obligation model bridging access control policies and privacy policies
Authors: Qun Ni, Elisa Bertino, Jorge Lobo
Venue: Proceedings of the 13th ACM symposium on Access control models and technologies (2008)

In this paper, we present a novel obligation model for the Core Privacy-aware Role Based Access Control (P-RBAC), and discuss some design issues in detail. Pre-obligations, post-obligations, conditional obligations, and repeating obligations are supported by the obligation model. Interaction between permissions and obligations is discussed, and efficient algorithms are provided to detect undesired effects.
Time-Stamping Authority Grid
Authors: T. Nishikawa, S. Matsuoka
Venue: Proceedings of the 2008 Eighth IEEE International Symposium on Cluster Computing and the Grid (2008)

Distributed time-stamping enables tolerance to distributed denial of service attacks. However, they involve high cost due to the requirement that all time-stamping units (TSUs), whose number could be numerous, must be audited by trusted third parties. We propose a distributed multi-generation time-stamping scheme with predictable expectation time of notary and minimizing the cost of administration. The scheme is called the "Time-Stamping Authority Grid" with "K = L + M among N in G generations scheme", where K is the number of issued requests, L is the number of requests to reliable TSUs, M is the number of requests to randomly chosen TSUs, N is the total number of TSUs, and G is the number of the generation that the requests are propagated. Our scheme solves the problems involving both centralized and previous distributed time-stamping schemes by constructing a peer-to-peer network of TSUs, thereby attaining the scalability and dramatically reduced cost.
Maximizing non-linear concave functions in fixed dimension
Authors: S. Toledo
Venue: Proceedings of the 33rd Annual Symposium on Foundations of Computer Science (1992)

Consider a convex set P in R/sup d/ and a piece wise polynomial concave function F: P to R. Let A be an algorithm that given a point x in IR/sup d/ computes F(x) if x in P, or returns a concave polynomial p such that p(x) or= 0. The author assumes that d is fixed and that all comparisons in A depend on the sign of polynomial functions of the input point. He shows that under these conditions, one can find max/sub P/ F in time which is polynomial in the number of arithmetic operations of A. Using this method he gives the first strongly polynomial algorithms for many nonlinear parametric problems in fixed dimension, such as the parametric max flow problem, the parametric minimum s-t distance, the parametric spanning tree problem and other problems. In addition he shows that in one dimension, the same result holds even if one only knows how to approximate the value of F. Specifically, if one can obtain an alpha -approximation for F(x) then one can alpha -approximate the value of maxF. He thus obtains the first polynomial approximation algorithms for many NP-hard problems such as the parametric Euclidean traveling salesman problem.
Joint cluster analysis of attribute data and relationship data: The connected k-center problem, algorithms and applications
Authors: Rong Ge, Martin Ester, Byron J. Gao, Zengjian Hu, Binay Bhattacharya, Boaz Ben-Moshe
Venue: ACM Transactions on Knowledge Discovery from Data (TKDD) (2008)

Attribute data and relationship data are two principal types of data, representing the intrinsic and extrinsic properties of entities. While attribute data have been the main source of data for cluster analysis, relationship data such as social networks or metabolic networks are becoming increasingly available. It is also common to observe both data types carry complementary information such as in market segmentation and community identification, which calls for a joint cluster analysis of both data types so as to achieve better results. In this article, we introduce the novel Connected k-Center (CkC) problem, a clustering model taking into account attribute data as well as relationship data. We analyze the complexity of the problem and prove its NP-hardness. Therefore, we analyze the approximability of the problem and also present a constant factor approximation algorithm. For the special case of the CkC problem where the relationship data form a tree structure, we propose a dynamic programming method giving an optimal solution in polynomial time. We further present NetScan, a heuristic algorithm that is efficient and effective for large real databases. Our extensive experimental evaluation on real datasets demonstrates the meaningfulness and accuracy of the NetScan results.
Electronic Voting Scheme to Maintain Anonymity in Small-scale Election by Hiding the Number of Votes
Authors: Tsukasa Endo, Isao Echizen, Hiroshi Yoshiura
Venue: Proceedings of the 2008 Third International Conference on Availability, Reliability and Security (2008)

Loss of anonymity, bribery, and coercion are more serious in small-scale voting than in large-scale voting. This paper shows that the entropy of each vote can be decreased, i.e., the anonymity of voting can be compromised, if the number of votes for each candidate is disclosed. It gives two strict definitions of anonymity instead of the previous definition and, based on the new definitions, proposes a new e-voting scheme that keeps the number of votes secret. The security of the proposed scheme is equivalent to that of an existing multiparty protocol.
Neighbourhood detection and identification of spatio-temporal dynamical systems using a coarse-to-fine approach
Authors: L. Z. Guo, S. S. Mei, S. A. Billings
Venue: International Journal of Systems Science (2007)

A novel approach to the determination of the neighbourhood and the identification of spatio-temporal dynamical systems is investigated. It is shown that thresholding to convert the pattern to a binary pattern and then applying cellular automata (CA) neighbourhood detection methods can provide an initial estimate of the neighbourhood. A coupled map lattice model can then be identified using the CA detected neighbourhood as the initial conditions. This provides a coarse-to-fine approach for neighbourhood detection and identification of coupled map lattice models. Three examples are used to demonstrate the application of the new approach.
Patently false?
Authors: Laurie Rowell
Venue: netWorker (2008)

A lawsuit now in federal appeals court may spell the end for software patents
Intersecting convex sets by rays
Authors: Radoslav Fulek, Andreas F. Holmsen, János Pach
Venue: Proceedings of the twenty-fourth annual symposium on Computational geometry (2008)

What is the smallest number τ = τ(n) such that for any collection of n pairwise disjoint convex sets in d-dimensional Euclidean space, there is a point such that any ray (half-line) emanating from it meets at most τ sets of the collection? This question of Urrutia is closely related to the notion of regression depth introduced by Rousseeuw and Hubert (1996). We show the following: Given any collection C of n pairwise disjoint compact convex sets in d-dimensional Euclidean space, there exists a point p such that any ray emanating from p meets at most dn+1)/d+1) members of C. There exist collections of n pairwise disjoint (i) equal length segments or (ii) disks in the Euclidean plane such that from any point there is a ray that meets at least 2n/3--2 of them. We also determine the asymptotic behavior of τ(n) when the convex bodies are fat and of roughly equal size.
A compiler-based infrastructure for software-protection
Authors: Clifford Liem, Yuan Xiang Gu, Harold Johnson
Venue: Proceedings of the third ACM SIGPLAN workshop on Programming languages and analysis for security (2008)

Not long after the introduction of stored-program computing machines, the first high-level language compilers appeared. The need for automatically and efficiently mapping abstract concepts from high-level languages onto low-level assembly languages has been recognized ever since. A compiler has a unique ability to gather and analyze large amounts of data in a manner that would be an unwieldy manual endeavor. It is this property that makes known compiler techniques and technology ideally suited for the purposes of software protection against reverse engineering and tampering attacks. In this paper, we present a code transformation infrastructure combined with build-time security techniques that are used to integrate protection into otherwise vulnerable machine programs. We show the applicability of known compiler techniques such as aliasanalysis, whole program analysis, data-flow analysis, and control-flow analysis and how these capabilities provide the basis for program transformations that provide comprehensive software protection. These methods are incorporated in an extensible framework allowing efficient development of new code transformations, as part of a larger suite of security tools for the creation of robust applications. We describe a number of successful applications of these tools.
Multivariate L∞ approximation in the worst case setting over reproducing kernel Hilbert spaces
Authors: Frances Y. Kuo, Grzegorz W. Wasilkowski, Henryk Woźniakowski
Venue: Journal of Approximation Theory (2008)

We study the worst case setting for approximation of d variate functions from a general reproducing kernel Hilbert space with the error measured in the L"~ norm. We mainly consider algorithms that use n arbitrary continuous linear functionals. We look for algorithms with the minimal worst case errors and for their rates of convergence as n goes to infinity. Algorithms using n function values will be analyzed in a forthcoming paper. We show that the L"~ approximation problem in the worst case setting is related to the weighted L"2 approximation problem in the average case setting with respect to a zero-mean Gaussian stochastic process whose covariance function is the same as the reproducing kernel of the Hilbert space. This relation enables us to find optimal algorithms and their rates of convergence for the weighted Korobov space with an arbitrary smoothness parameter @a>1, and for the weighted Sobolev space whose reproducing kernel corresponds to the Wiener sheet measure. The optimal convergence rates are n^-^(^@a^-^1^)^/^2 and n^-^1^/^2, respectively. We also study tractability of L"~ approximation for the absolute and normalized error criteria, i.e., how the minimal worst case errors depend on the number of variables, d, especially when d is arbitrarily large. We provide necessary and sufficient conditions on tractability of L"~ approximation in terms of tractability conditions of the weighted L"2 approximation in the average case setting. In particular, tractability holds in weighted Korobov and Sobolev spaces only for weights tending sufficiently fast to zero and does not hold for the classical unweighted spaces.
Virtualizing the data plane through source code merging
Authors: Eric Keller, Evan Green
Venue: Proceedings of the ACM workshop on Programmable routers for extensible services of tomorrow (2008)

Virtualization is a key technology that enables multiple research groups to test new protocols simultaneously on the same physical network and also allows service providers to incrementally add new services. In this paper we focus on virtualization of the data plane, allowing for customized packet handling in each virtual network. Much work has been done on virtualization technology. However, this has been focused on the user application experience or on a fixed networking stack. Rather than running custom data planes in user space or running separate guest operating systems, both of which come at a performance hit, we propose running a single kernel-level custom data-plane by synthesizing the configuration of the per-virtual-network data planes. In this paper we present this idea using Click, where packet processing is specified as an interconnection of fixed networking tasks. We then demonstrate the idea using an unvirtualized Linux kernel as the target platform, showing how we provided isolation between the customized data plane.
An efficient three-step iterative method with sixth-order convergence for solving nonlinear equations
Authors: A. Rafiq, S. Hussain, F. Ahmad, M. Awais, F. Zafar
Venue: International Journal of Computer Mathematics (2007)

In this paper, we present a new three-step predictor corrector type iterative method for finding simple and real roots of nonlinear equations in a single variable. Experiments show that the new method is more efficient than the well known methods available in the literature. Comparison tables are given demonstrating the importance of the proposed approach.
Promoting B2B Integration with Semantic Web Service Technologies
Authors: Seyyed Ali Rokni Dezfouli, Jafar Habibi, Soheil Hassas Yeganeh
Venue: Proceedings of the 2008 Second Asia International Conference on Modelling & Simulation (AMS) (2008)

Several e-business frameworks are developed to definestandards for information sharing within and betweencompanies. These frameworks only standardizestructure of messages and aren’t able to definesemantics. It leads to slow and costly dynamicBusiness-to-Business (B2B) integration. The use ofSemantic Web Service (SWS) technologies has beensuggested to enable more dynamic B2B integration ofheterogeneous systems and partners. We present asemantic B2B mediator based on the WSMX –a SWSexecution environment, to tackle heterogeneities inB2B services. We particularly show how WSMX can bemade to support the RosettaNet e-business frameworkand how it can add dynamics to B2B interactions byautomating mediation of heterogeneous messages. Weused a reasoner in interaction with WSMX forautomatic consistency checking of instances in runtime.The benefits of applying SWS technologiesinclude more flexibility in accepting heterogeneity inB2B integrations and easing back-end integrations.This allows introducing more competition into thepurchasing process within e-business frameworks.
Students learn CS in different ways: insights from an empirical study
Authors: Anders Berglund, Mattias Wiggberg
Venue: Proceedings of the tenth conference on Australasian computing education - Volume 78 (2008)

This empirical study demonstrates that students' learning of computer science takes place in qualitatively different ways. The results consist of categories, where each category describes a certain way in which the students approach their learning. The paper demonstrates that some of the ways of tackling learning do better than others in producing a good learning outcome, and that they should therefore be encouraged. The data underlying these results were collected through interviews with third and fourth year students in two countries, and were analysed using a phenomenographic research approach.
How medical expertise influences web search interaction
Authors: Ryen W. White, Susan Dumais, Jaime Teevan
Venue: Proceedings of the 31st annual international ACM SIGIR conference on Research and development in information retrieval (2008)

Domain expertise can have an important influence on how people search. In this poster we present findings from a log-based study into how medical domain experts search the Web for information related to their expertise, as compared with non-experts. We find differences in sites visited, query vocabulary, and search behavior. The findings have implications for the automatic identification of domain experts from interaction logs, and the use of domain knowledge in applications such as query suggestion or page recommendation to support non-experts.
Automated hardware-independent scenario identification
Authors: Juan Hamers, Lieven Eeckhout
Venue: Proceedings of the 45th annual Design Automation Conference (2008)

Scenario-based design exploits the time-varying execution behavior of applications by dynamically adapting the system on which they run. This is a particularly interesting design methodology for media applications with soft realtime constraints such as decoders: frames can be classified into scenarios based on their decode complexity, and the system can be configured on a per-scenario basis such that energy consumption is reduced while still meeting the deadlines. At the foundation of scenario-based design lies the ability to identify scenarios, or recurring modes of operation with similar run time characteristics. There are two opposite ends to scenario identification. Some researchers have proposed techniques that, based on domain knowledge, identify hardware-independent scenarios in a media input stream. At the other end, other researchers have proposed techniques that identify hardware-dependent scenarios in a (semi-) automated way. This paper proposes a scenario identification approach that bridges both opposite ends, and finds hardware-independent scenarios in an automated way. It does so by computing execution profiles on a per-frame basis that capture the application's code execution patterns. We find that Edge Vectors (EVs) are more accurate than Basic Block Vectors (BBVs) at capturing the variation in frame-level decode complexity. The complexity of the proposed automated scenario identification is comparable to existing hardware-dependent scenario identification approaches, yet the scenarios can be used across hardware implementations.
Brushless DC motor: position linear control simulation
Authors: F. A. Barata, J. C. Quadrado, J. Fernando Silva
Venue: Proceedings of the 9th WSEAS International Conference on Systems (2005)

The Brushless Direct Current (BLDC) motor is one of the motors types rapidly gaining attractiveness. Actually they are becoming widely used in various consumer and industrial systems. As the name implies, BLDC motors do not use brushes for commutation, they are electronically commutated. This paper presents a Matlab simulation model that includes the control speed and position of a trapezoidal back-emf BLDC motor. The model consists of position and speed linear controllers, reference current generation, current controller and a three phase voltage inverter. Most of the applications now use a Pulse Width Modulation (PWM) current controller. The solution here proposed it new because it uses a hysteretic vectorial control in αβ to control the current.
Long-range percolation mixing time
Authors: Itai Benjamini, Noam Berger, Ariel Yadin
Venue: Combinatorics, Probability and Computing (2008)

We provide an estimate, sharp up to poly-logarithmic factors, of the asymptotic almost sure mixing time of the graph created by long-range percolation on the cycle of length N (<inline-graphic mime-subtype="gif" xlink="S0963548308008948_inline1"><alt-text>$\Integer/N\Integer$</alt-text></inline-graphic>). While it is known that the asymptotic almost sure diameter drops from linear to poly-logarithmic as the exponent s decreases below 2 [4, 9], the asymptotic almost sure mixing time drops from N2 only to Ns-1 (up to poly-logarithmic factors).
ACM 2007 Kanellakis Award Honours Bruno Buchberger Innovator of Automated Tools for Mathematics
Authors: Mark Giesbrecht
Venue: ACM Communications in Computer Algebra (2008)

SIGSAM is pleased to announce that Bruno Buchberger of the Research Institute for Symbolic Computation (RISC) at Johannes Kepler University in Linz, Austria, has been awarded the 2007 ACM Paris Kanellakis Theory and Practice Award. This is one of the ACM's top prizes and recognizes his role in developing Gröbner bases. We congratulate Bruno for this outstanding achievement and honour!