ppxscal/embedding_network huggingface dataset:
MeshChord: A Location-Aware, Cross-Layer Specialization of Chord for Wireless Mesh Networks (concise contribution)
Authors: Simone Burresi, Claudia Canali, M. Elena Renda, Paolo Santi
Venue: Proceedings of the 2008 Sixth Annual IEEE International Conference on Pervasive Computing and Communications (2008)

Wireless mesh networks are a promising area for the deployment of new wireless communication and networking technologies. In this paper, we address the problem of enabling effective peer-to-peer resource sharing in this type of networks. Starting from the well-known Chord protocol for resource sharing in wired networks,we propose a specialization (called MeshChord) that accounts for peculiar features of wireless mesh networks: namely,the availability of a wireless infrastructure, and the 1-hop broadcast nature of wireless communication.Through extensive packet-level simulations, we show that MeshChord reduces message overhead of as much as 40%with respect to the basic Chord design, while at the same time improving the information retrieval performance. Overall, the results of our study suggest thatMeshChord can be successfully utilized for implementing file/resource sharing applications in wireless mesh networks.
Visualizing and exploring planar algebraic arrangements: a web application
Authors: Pavel Emeliyanenko, Michael Kerber
Venue: Proceedings of the twenty-fourth annual symposium on Computational geometry (2008)

A web application is presented to compute, plot, and interactively explore planar arrangements induced by algebraic plane curves of arbitrary degree. It produces accurate curve plots and reflects the exact topology for any arrangement, including degenerated cases. Various user interface features allow the interactive exploration of the arrangement structure. This makes the tool useful for demonstrative and educational purposes, especially as it runs without initial installation process.
An extension of Fisher's discriminant analysis for stochastic processes
Authors: Hyejin Shin
Venue: Journal of Multivariate Analysis (2008)

In this paper we present a general notion of Fisher's linear discriminant analysis that extends the classical multivariate concept to situations that allow for function-valued random elements. The development uses a bijective mapping that connects a second order process to the reproducing kernel Hilbert space generated by its within class covariance kernel. This approach provides a seamless transition between Fisher's original development and infinite dimensional settings that lends itself well to computation via smoothing and regularization. Simulation results and real data examples are provided to illustrate the methodology.
EMI reduction technique by employing a conductive connection between frames
Authors: Eun-Kwang Koh, Min-Kyu Shim, Eun-Ju Hong, Jai-Yeol Lee, Seung-Hun Park, In-Gu Kwak, Wansoo Nah
Venue: Proceedings of the 2nd international conference on Ubiquitous information management and communication (2008)

In this paper, we propose an EMI (Electromagnetic Interference) reduction technique by employing a conductive connection between frames. Several cconductors were used to connect two frames, which might provide another return path of signal current loop, and reduce the DM (Differential Mode) radiation from the cable. To prove the effectiveness of the conductor connection, we investigated two cases: (1) without any conductor below cable, (2) installing three different conductors of small, medium, and large sized-conductors. The results were obtained from both measurement and full-wave simulation, and we observed that EMI decreased about 1 to 10 dB &mu;V in the frequency range from 30MHz to 1GHZ.
Fault tolerance in cellular automata at high fault rates
Authors: Mark McCann, Nicholas Pippenger
Venue: Journal of Computer and System Sciences (2008)

A commonly used model for fault-tolerant computation is that of cellular automata. The essential difficulty of fault-tolerant computation is present in the special case of simply remembering a bit in the presence of faults, and that is the case we treat in this paper. We are concerned with the degree (the number of neighboring cells on which the state transition function depends) needed to achieve fault tolerance when the fault rate is high (nearly 1/2). We consider both the traditional transient fault model (where faults occur independently in time and space) and a recently introduced combined fault model which also includes manufacturing faults (which occur independently in space, but which affect cells for all time). We also consider both a purely probabilistic fault model (in which the states of cells are perturbed at exactly the fault rate) and an adversarial model (in which the occurrence of a fault gives control of the state to an omniscient adversary). We show that there are cellular automata that can tolerate a fault rate 1/2-@x (with @x>0) with degree O((1/@x^2)log(1/@x)), even with adversarial combined faults. The simplest such automata are based on infinite regular trees, but our results also apply to other structures (such as hyperbolic tessellations) that contain infinite regular trees. We also obtain a lower bound of @W(1/@x^2), even with only purely probabilistic transient faults.
Integrating Direct3D Programming into Computer Science Curriculum
Authors: Delin Tan, Shou-Hsuan Stephen Huang
Venue: Proceedings of the Fifth International Conference on Information Technology: New Generations (2008)

In recent years, Computer Graphics and Game Programming has become a popular topic among students. We propose a course that uses Microsoft DirectX as the platform for teaching undergraduate computer graphics. This course can be taught in a one-semester undergraduate course with a data structure course as prerequisite. The design of the course is described in the paper.
A Co-Evolutionary Fuzzy System for Real-Time Signal Pre-Processing
Authors: Sedigheh Khajoui Nejad, Amir Najafi-Ardabili, Mohammad-R. Akbarzadeh-T, M-Hossein Moeinzadeh
Venue: Proceedings of the 2008 Second Asia International Conference on Modelling & Simulation (AMS) (2008)

By their nature, Real-Time applications impose the conflicting goals of providing a fast algorithm and reducing the rate of error as much as possible. The Remote Terminal Units (RTU) has a real-time system to convert the data from the field into pulses/counts at the converter stage and transmits them to the main processor. In this paper we take advantage of the fuzzy logic inference system, as a pre-processor which is optimized by an evolutionary algorithm in a cooperative co-evolutionary manner. The novelty of the proposed method is that our system will be optimized by a co-evolutionary algorithm and the output would then be implemented as a lookup table suitable for real-time processing. Simulations demonstrate the most significant improvement to reduce the time complexity down to O (1) and enhance the precision simultaneously.
A simple local-control approximation algorithm for multicommodity flow
Authors: B. Awerbuch, T. Leighton
Venue: Proceedings of the 1993 IEEE 34th Annual Foundations of Computer Science (1993)

In this paper, we describe a very simple (1+/spl epsi/)-approximation algorithm for the multicommodity flow problem. The algorithm runs in time that is polynomial in N (the number of nodes in the network) and /spl epsiv//sup -1/ (the closeness of the approximation to optimal). The algorithm is remarkable in that it is much simpler than all known polynomial time flow algorithms (including algorithms for the special case of one-commodity flow). In particular, the algorithm does not rely on augmenting paths, shortest paths, min-cost paths, or similar techniques to push flow through a network. In fact, no explicit attempt is ever made to push flow towards a sink during the algorithm. Because the algorithm is so simple, it can be applied to a variety of problems for which centralized decision making and flow planning is not possible. For example, the algorithm can be easily implemented with local control in a distributed network and it can be made tolerant to link failures. In addition, the algorithm appears to perform well in practice. Initial experiments using the DIMACS generator of test problems indicate that the algorithm performs as well as or better than previously known algorithms, at least for certain test problems.
Simulation Experiments with Self Tuning PSD Control Algorithm
Authors: Mikulá Alexík
Venue: Proceedings of the Tenth International Conference on Computer Modeling and Simulation (2008)

This paper introduces self-tuning identification free PSD control algorithm and its new modification. On the basis of detailed analysis of algorithm function made by simulation experiments, several modification of original algorithm have been proposed, realized and checked. These were executed in simulation environments created by real time operating analogue models of controlled processes, connected with PC through A/D and D/A converters. Verification of control loop performance quality was executed by simulation experiments with proportional second to five order controlled processes for step responses on set point and disturbance. These experiments were executed in real time. Loop responses were characterized with numeric data quality of control loop step response behavior.
Multiplex polymerase chain reaction (PCR) on a SU-8 chip
Authors: Troels Balmer Christensen, Dang Doung Bang, Anders Wolff
Venue: Microelectronic Engineering (2008)

We present the detection of Campylobacter at species level using multiplex PCR in a micro fabricated PCR chip. The chip is based on the polymer SU-8 that allows integration with different microfluidic components, e.g., sample pre-treatment before PCR, and DNA detection simultaneously with or after the PCR. The chip performs very well with respect to heating and cooling rates with values up to around 40^oC/s and 20^oC/s, respectively, and has low power consumption (0.5-2.5W depending on temperature). Multiplex DNA amplification by PCR for the detection of Campylobacter at species level was performed successfully on the chip with results comparable to conventional PCR methods. Microsystems often show serious PCR inhibition due to a high surface to volume ratio which causes an increased proclivity of the PCR mix ingredients to stick to the surfaces. To avoid this, a simple method of dynamic surface modification by adding BSA to the PCR mix was utilized.
Algorithm 880: A testing infrastructure for symmetric tridiagonal eigensolvers
Authors: Osni A. Marques, Christof Vömel, James W. Demmel, Beresford N. Parlett
Venue: ACM Transactions on Mathematical Software (TOMS) (2008)

LAPACK is often mentioned as a positive example of a software library that encapsulates complex, robust, and widely used numerical algorithms for a wide range of applications. At installation time, the user has the option of running a (limited) number of test cases to verify the integrity of the installation process. On the algorithm developer's side, however, more exhaustive tests are usually performed to study algorithm behavior on a variety of problem settings and also computer architectures. In this process, difficult test cases need to be found that reflect particular challenges of an application or push algorithms to extreme behavior. These tests are then assembled into a comprehensive collection, therefore making it possible for any new or competing algorithm to be stressed in a similar way. This article describes an infrastructure for exhaustively testing the symmetric tridiagonal eigensolvers implemented in LAPACK. It consists of two parts: a selection of carefully chosen test matrices with particular idiosyncrasies and a portable testing framework that allows for easy testing and data processing. The tester facilitates experiments with algorithmic choices, parameter and threshold studies, and performance comparisons on different architectures.
Computational complexity of auditing finite attributes in statistical databases
Authors: Peter Jonsson, Andrei Krokhin
Venue: Journal of Computer and System Sciences (2008)

We study the computational complexity of auditing finite attributes in databases allowing statistical queries. Given a database that supports statistical queries, the auditing problem is to check whether an attribute can be completely determined or not from a given set of statistical information. Some restricted cases of this problem have been investigated earlier, e.g. the complexity of statistical sum queries is known by the work of Kleinberg et al. (J. Comput. System Sci. 66 (2003) 244-253). We characterize all classes of statistical queries such that the auditing problem is polynomial-time solvable. We also prove that the problem is coNP-complete in all other cases under a plausible conjecture on the complexity of constraint satisfaction problems (CSP). The characterization is based on the complexity of certain CSP problems; the exact complexity for such problems is known in many cases. This result is obtained by exploiting connections between auditing and constraint satisfaction, and using certain algebraic techniques. We also study a generalization of the auditing problem where one asks if a set of statistical information imply that an attribute is restricted to K or less different values. We characterize all classes of polynomial-time solvable problems in this case, too.
Towards Automatic Middleware Generation
Authors: Bechir Zalila, Laurent Pautet, Jérôme Hugues
Venue: Proceedings of the 2008 11th IEEE Symposium on Object Oriented Real-Time Distributed Computing (2008)

Building middleware for distributed applications is a complex task, mixing antagonistic concerns: heterogeneity, performance, reliability, quality of services. Optimization and fine-tuning of middleware for a particular application is even a harder task, usually done manually or through complex design patterns. The advent of "schizophrenic'' middleware which separates concerns between distribution model, communication protocols, and their implementation by refining the definition and role of "personalities'' brought some elements to solve this problem by enabling full tailoring of the middleware by the developer. In this paper we extend this approach to full automation by generating middleware from an architectural model of the system expressed in a modeling language. This enables precise tuning and configuration of the middleware by generating exactly the required code, prior to runtime. We finally show how this approach fits the requirements of high-integrity or real-time distributed systems.
Accelerated AES implementations via generalized instruction set extensions
Authors: A. J. Elbirt
Venue: Journal of Computer Security (2008)

Efficient implementation of block ciphers is critical towards achieving both high security and high-speed processing. Numerous block ciphers, including the Advanced Encryption Standard (AES), have been proposed and implemented, using a wide and varied range of functional operations. Existing microprocessor architectures do not provide this broad range of support. However, the advent of intellectual property (IP) processor cores presents the opportunity to augment existing datapaths with instruction set extensions to add acceleration modules in the form of new instructions. We will present a general purpose instruction set extension to a 32-bit SPARC V8 compatible processor core that accelerates the performance of Galois Field fixed field constant multiplication, a core element of the AES algorithm. This extension will be shown to accelerate AES encryption versus pure software implementations at a small hardware cost. This matches the improvement demonstrated in previously proposed AES-specific instruction set extensions while maintaining a generalized implementation format capable of supporting other algorithms that use Galois Field fixed field constant multiplication.
A numerical study for the homogenisation of one-dimensional models describing the motion of dislocations
Authors: M-A. Ghorbel, P. Hoch, R. Monneau
Venue: International Journal of Computing Science and Mathematics (2008)

In this paper we are interested in the collective motion of dislocations defects in crystals. Mathematically, we study the homogenisation of a non-local Hamilton-Jacobi equation. We prove some qualitative properties on the effective Hamiltonian and we provide a numerical scheme which is proved to be monotone under some suitable CFL conditions. Using this scheme, we compute numerically the effective Hamiltonian. Furthermore, we provide numerical computations of the effective Hamiltonian for several models corresponding to the dynamics of dislocations where no theoretical analysis is available.
Digmap: a service for searching and browsing old maps
Authors: Gilberto Pedrosa, João Luzio, Hugo Manguinhas, Bruno Martins
Venue: Proceedings of the 8th ACM/IEEE-CS joint conference on Digital libraries (2008)

DIGMAP aims to become the main international resource discovery service for digitized old maps existing in libraries. The service reuses metadata from European national libraries and other relevant third party metadata sources. The gathered metadata is enhanced locally with geographical indexing and with record linking/clustering, leveraging on geographic gazetteers and authority files. When available, the images of the maps are also processed to extract potentially relevant features. This made it possible to develop a rich integrated environment for searching and browsing services with four perspectives: image's features, textual, geographic and temporal information.
Toward a Message-Oriented Application Model and its Middleware Support in Ubiquitous Environments
Authors: Chun-Feng Liao, Ya-Wen Jong, Li-Chen Fu
Venue: Proceedings of the 2008 International Conference on Multimedia and Ubiquitous Engineering (2008)

Context-awareness has become a distinguishing feature of Ubiquitous systems. Contrary to desktop and web applications, Ubiquitous applications gather environmental context and provide services without user intervention. In this paper, we propose a message-oriented application model that is capable of modeling both user and system initiative interaction paradigms [1]. Systems designed based on this model are inherently loosely-coupled and scalable. Results of this research include a systematic development procedure and its supporting middleware. We show the feasibility of this model by constructing several Ubiquitous applications for two dissimilar demo sites, and discuss experiences when adopting this model.
Game chromatic index of k-degenerate graphs
Authors: Leizhen Cai, Xuding Zhu
Venue: Journal of Graph Theory (2001)

We consider the following edge coloring game on a graph G. Given t distinct colors, two players Alice and Bob, with Alice moving first, alternately select an uncolored edge e of G and assign it a color different from the colors of edges adjacent to e. Bob wins if, at any stage of the game, there is an uncolored edge adjacent to colored edges in all t colors; otherwise Alice wins. Note that when Alice wins, all edges of G are properly colored. The game chromatic index of a graph G is the minimum number of colors for which Alice has a winning strategy. In this paper, we study the edge coloring game on k-degenerate graphs. We prove that the game chromatic index of a k-degenerate graph is at most &Delta;&thinsp;+&thinsp;3k&thinsp;-&thinsp;1, where &Delta; is the maximum vertex degree of the graph. We also show that the game chromatic index of a forest of maximum degree 3 is at most 4 when the forest contains an odd number of edges. &copy; 2001 John Wiley & Sons, Inc. J Graph Theory 36: 144&ndash;155, 2001
Global information technology and global citizenship education
Authors: Richard Ennals, Les Stratton, Noura Moujahid, Serhiy Kovela
Venue: AI Society (2008)

The Council for Education in World Citizenship has been working with Kingston University and the UK National Commission for UNESCO, taking advantage of global information technology developments in order to build new programmes for global citizenship education. The paper reports on practical experience, inviting new network partners. The IST-Africa 2007 conference provided an opportunity to build on these foundations, with initiatives in primary, secondary, further, adult and higher education, and continuing professional development for teachers.
Multi-reflection based on chip label free molecules detection
Authors: L. Billot, A. Plecis, Y. Chen
Venue: Microelectronic Engineering (2008)

We report on results of a simple optical method based on multi-reflection in a microfluidic device. The multi-reflection mirrors were integrated into the device of a Glass-PDMS-Glass sandwich configuration. To evaluate the performance of such a simple label free detection method, absorption spectra of a variety of chemical and biological species were analysed by changing mirror reflectance as well as the molecular concentration of the samples.
Comparative evaluation of the non-contiguous processor allocation strategies based on a real workload and a stochastic workload on multicomputers
Authors: S. Bani-Mohammad, M. Ould-Khaoua, I. Ababneh, Lewis M. Mackenzie
Venue: Proceedings of the 13th International Conference on Parallel and Distributed Systems - Volume 02 (2007)

The performance study of the existing noncontiguous processor allocation strategies has been traditionally carried out by means of simulation based on a stochastic workload model to generate a stream of incoming jobs that are submitted to and run on a given message passing parallel machine for a period of time. To validate the performance of the existing allocation algorithms, there has been need to evaluate the algorithms&#x2019; performance based on a real workload trace. In this study, we evaluate the performance of several well-known processor allocation and job scheduling strategies based on a real workload trace and compare the results against those obtained from using a stochastic workload. Our results reveal that the conclusions reached on the relative performance merits of the allocation strategies when a real workload trace is used are in general compatible with those obtained when a stochastic workload is used.
Fuzzy algorithm representation for its application in intelligent tutoring systems for the learning of programming
Authors: Francisco Jurado, Miguel Ángel Redondo, Manuel Ortega
Venue: Proceedings of the 2007 Euro American conference on Telematics and information systems (2007)

Intelligent Tutoring Systems (ITS) allow an adaptation of the instructional strategy to the student. The ITS that operate with the Problem Based Learning (PBL) educative paradigm need to model the domain and the solution. It will allow determining which learning activity the student has to do next in an adaptive learning process. This paper is centered on those ITS oriented to the teaching of algorithm programming. A proposal that makes use of fuzzy logic applied to a set of metric characteristics of an algorithm will be shown, with the purpose of obtaining a fuzzy representation. Thus, it can be used to analyze the algorithms written by the students, as solutions to the problems presented.
Towards human-like spoken dialogue systems
Authors: Jens Edlund, Joakim Gustafson, Mattias Heldner, Anna Hjalmarsson
Venue: Speech Communication (2008)

This paper presents an overview of methods that can be used to collect and analyse data on user responses to spoken dialogue system components intended to increase human-likeness, and to evaluate how well the components succeed in reaching that goal. Wizard-of-Oz variations, human-human data manipulation, and micro-domains are discussed in this context, as is the use of third-party reviewers to get a measure of the degree of human-likeness. We also present the two-way mimicry target, a model for measuring how well a human-computer dialogue mimics or replicates some aspect of human-human dialogue, including human flaws and inconsistencies. Although we have added a measure of innovation, none of the techniques is new in its entirety. Taken together and described from a human-likeness perspective, however, they form a set of tools that may widen the path towards human-like spoken dialogue systems.