ppxscal/embedding_network huggingface dataset:
Edge-and-corner preserving regularization for image interpolation and reconstruction
Authors: Wen-Ze Shao, Zhi-Hui Wei
Venue: Image and Vision Computing (2008)

The edge and corner structures are two categories of perceptually important image characteristics, and hence, edge-and-corner preserving regularization is required for many problems in image processing. In this paper, the first novelty is to propose a new edge-and-corner preserving approach for image interpolation, based on the coupling of robust orientation diffusion, edge shock filtering, and a type of newly designed corner shock filtering. The proposed interpolation scheme is not only able to remove the staircase artifacts along the edge structures, but also able to restrain the rounding artifacts around the corner structures. The second novelty in this paper is to analyze the filtering behavior of two standard structure tensor based variational PDE (partial differential equation) approaches, following which an edge-and-corner preserving common PDE framework is proposed for different applications in image processing. Numerous experimental results confirm the effectiveness of the proposed interpolation approach, and demonstrate its superiority to other interpolation algorithms. The common PDE framework is applied to several other image processing problems, including image denoising, deringing, deblocking, inpainting, and super-resolution reconstruction.
Resource-Aware Verification Using Randomized Exploration of Large State Spaces
Authors: Nazha Abed, Stavros Tripakis, Jean-Marc Vincent
Venue: Proceedings of the 15th international workshop on Model Checking Software (2008)

Exhaustive verification often suffers from the state-explosion problem, where the reachable state space is too large to fit in main memory. For this reason, and because of disk swapping, once the main memory is full very little progress is made, and the process is not scalable. To alleviate this, partial verification methods have been proposed, some based on randomized exploration, mostly in the form of random walks. In this paper, we enhance partial, randomized state-space exploration methods with the concept of resource-awareness: the exploration algorithm is made aware of the limits on resources, in particular memory and time. We present a memory-aware algorithm that by design never stores more states than those that fit in main memory. We also propose criteria to compare this algorithm with similar other algorithms. We study properties of such algorithms both theoretically on simple classes of state spaces and experimentally on some preliminary case studies.
Local Terminations and Distributed Computability in Anonymous Networks
Authors: Jérémie Chalopin, Emmanuel Godard, Yves Métivier
Venue: Proceedings of the 22nd international symposium on Distributed Computing (2008)

We investigate the computability of distributed tasks in reliable anonymous networks with arbitrary knowledge. More precisely, we consider tasks computable with local termination, i.e., a node knows when to stop to participate in a distributed algorithm, even though the algorithm is not necessarily terminated elsewhere. We also study weak local termination, that is when a node knows its final value but continues to execute the distributed algorithm, usually in order to provide information to other nodes.We give the first characterization of distributed tasks that can be computed with weak local termination and we present a new characterization of tasks computed with local termination. For both terminations, we also characterize tasks computable by polynomial algorithms.
Analysis of a Spectrum Awareness Algorithm for Cognitive Radios
Authors: Cuiran Li, Shubin Liu, Chengshu Li
Venue: Proceedings of the 2008 Congress on Image and Signal Processing, Vol. 4 - Volume 04 (2008)

Recently, the technology of cognitive radio (CR) has captured the attention of many researchers in that it promises an effective way of enhancing spectrum usage and solving the problem of heterogeneity of radio devices. For the CR network, a fundamental issue is how to identify the spectrum opportunities. To improve the sensing performance, cooperative spectrum sensing has been proposed. With the conventional sensing method, every cognitive user conducts its individual spectrum sensing by comparing the observation with a pre-fixed threshold and then sends a binary local decision to the common receiver. In the paper, we introduce a novel spectrum scheme based on the trustiness factor (TF) and fussy decision. According to the energy detection, if the energy is located in the energy region with TF=1, then the cognitive user sends 1 bit quantization for reporting its sensing result. Otherwise, the cognitive user sends 2 bits quantization. A final decision therefore is made according to the reporting results. Simulation results show that the proposed sensing scheme outperforms the conventional method in terms of missing probability without noticeable loss in quantization performance.
An Educational Component-Based Digital TV Middleware for the Brazilian's System
Authors: Juliano Rodrigues Costa, Vicente Ferreira Lucena,  Jr.
Venue: Proceedings of the 3rd international conference on Technologies for E-Learning and Digital Entertainment (2008)

One of the major problems faced by the Brazilian population is the low level of the fundamental schools. Television is the most popular source of entertainment and information of the Brazilian population being present in approximately 54 million families all over the country. These families watch television for more than 8 hours daily. Moreover, at this moment, the Brazilian TV system is moving from analog to digital. That means not only that image and sound will be delivered with much better quality but also that it will be possible to send interactive multimedia programs, creating a brand new way of watching TV. That is in fact the main novelty of the digital system it will be possible to offer personal interactive services such as banking, games and most importantly educational programs. This work introduces a software framework called "Extended Middleware for Digital TV (EMTV)" which is suitable for the generation of interactive applications executed over digital television systems. Its concept was developed focusing on the Brazilian technological options for Digital TV. Technically, EMTV is a procedural GEM compliant application which, from the programmer's point of view, acts as a declarative middleware extension. The framework was developed to be component-based in order to minimize the need for programming knowledge to deploy the digital TV applications using EMTV. The main goal of the platform is to facilitate the construction of interactive multimedia educational applications, a crucial field for the Brazilian population. The concept is tested and validated by the construction of a Quiz application presented at the end of the paper.
A Timing-Resistant Elliptic Curve Backdoor in RSA
Authors: Adam L. Young, Moti Yung
Venue: Information Security and Cryptology: Third SKLOIS Conference, Inscrypt 2007, Xining, China, August 31 - September 5, 2007, Revised Selected Papers (2007)

We present a fast algorithm for finding pairs of backdoor RSA primes (p,q) given a security parameter. Such pairs posses an asymmetric backdoor that gives the designer the exclusive ability to factor n = pq, even when the key generation algorithm is public. Our algorithm uses a pair of twisted curves over GF(2257) and we present the first incremental search method to generate such primes. The search causes the $\frac{1}{2}$log(n)+O(log(log(n))) least significant bits of n to be modified during key generation after p is selected and before q is determined. However, we show that this is tolerable by using point compression and ECDH. We also present the first rigorous experimental benchmarks of an RSA asymmetric backdoor and show that our OpenSSL-based implementation outperforms OpenSSL RSA key generation. Our application is highly efficient key recovery. Of independent interest, we motivate the need to find large binary twists. We present the twist we generated and how we found it.
An exploration into two solutions to propagating web accessibility for blind computer users
Authors: Bambang Parmanto
Venue:  (2007)

A model is presented depicting the driving forces (Web industry, consumers, U.S. federal government, and technology) promoting an accessible Web and potential solutions within those forces. This project examines two distinct solutions, lawsuits (a consumer-driven solution) and AcceSS 2.1 transcoder (a technology-driven solution) to provide more information on two under-researched methods that could have far-reaching impacts on Web accessibility for the blind. First, an evaluation of the intraclass correlation (ICC) between homepage Web Accessibility Barrier (WAB) scores and WAB scores of levels 1-3 found that the homepage is not sufficient to detect the accessibility of the website. ICC of the homepage and average of levels 1-3 is 0.250 (p=0.062) and ICC of levels 1, 2, 3 is 0.784 (p < 0.0001). Evaluating the homepage and first-level pages gives more accurate results of entire site accessibility. Second, an evaluation of the WAB scores of the homepage and first-level pages of websites of five companies sued for alleged inaccessible websites found mixed results: lawsuits worked in two cases, but didn&rsquo;t in three. This is seen through an examination of accessibility and complexity of the websites for years surrounding the lawsuits. Each sued website is compared to a control website within the same industry and to a random group of websites representing the general Web. Third, a usability study of the AcceSS 2.1 transcoding intermediary found that technology can increase users&rsquo; efficiency, effectiveness, and satisfaction in Web interaction, regardless of universal design. The study entails a within-subject cross-over design wherein 15 users performed tasks on three websites: one universally designed, one non-universally designed, and one reference site. Paired t-tests examine the effect of AcceSS 2.1 on time, errors, and subjective satisfaction and mixed-model analysis examines the effect of study design on outcomes. Results show that users perform tasks faster, with fewer errors, and with greater satisfaction when accessing pages via AcceSS 2.1, but users where less satisfied with the universally designed website and significant differences were found in the universally designed website and not the non-universally designed website. Website usability and ease of navigation are more important to users than simple accessibility.
Iterative Parameter Estimation of Chirp Signals Based on Cyclostationarity
Authors: Yan Jin, Hongbing Ji
Venue: Proceedings of the 2008 Congress on Image and Signal Processing, Vol. 5 - Volume 05 (2008)

The problem of concern here is the parameter estimation of chirp signals in the presence of additive noise. An improved cyclostationarity based algorithm is proposed to estimate the phase parameters. The novelty of the proposed algorithm lies in the iterative estimation of the second-order parameters. The main characteristics of the method include reduction in error propagation effect, increase in estimation accuracy, and operation over a wider range of phase parameter values. Simulation results demonstrate that the proposed algorithm has better performance as compared with the conventional cyclostationary estimation method.
Multi-agent Learning Dynamics: A Survey
Authors: H. Jaap Herik, D. Hennes, M. Kaisers, K. Tuyls, K. Verbeeck
Venue: Proceedings of the 11th international workshop on Cooperative Information Agents XI (2007)

In this paper we compare state-of-the-art multi-agent reinforcement learning algorithms in a wide variety of games. We consider two types of algorithms: value iteration and policy iteration. Four characteristics are studied: initial conditions, parameter settings, convergence speed, and local versus global convergence. Global convergence is still difficult to achieve in practice, despite existing theoretical guarantees. Multiple visualizations are included to provide a comprehensive insight into the learning dynamics.
The Equitable Edge-Coloring of Series-Parallel Graphs
Authors: Huimin Song, Jianliang Wu, Guizhen Liu
Venue: Proceedings of the 7th international conference on Computational Science, Part III: ICCS 2007 (2007)

An edge-coloring of a graph G is equitable if, for each vertex v of G, the number of edges of any one color incident with v differs from the number of edges of any other color incident with v by at most one. A graph G is called equitable if G has an equitable edge-coloring with k colors for any integer k ¿ 1. A plane graph is series-parallel graph if it contains no subgraphs homeomorphic to K 4. In the paper, we prove that any simple and connected series-parallel graph is equitable if and only if it is not an odd circuit.
Genetic-Greedy Hybrid Approach for Topological Active Nets Optimization
Authors: José Santos, Óscar Ibáñez, Noelia Barreira, Manuel G. Penedo
Venue: Proceedings of the 8th international conference on Adaptive and Natural Computing Algorithms, Part I (2007)

In this paper we propose a genetic and greedy algorithm combination for the optimization of the Topological Active Nets (TAN) model. This is a deformable model used for image segmentation that integrates features of region-based and edge-based segmentation techniques, being able to fit the edges of the objects and model their inner topology. The hybrid approach we propose can optimize the active nets through the minimization of the model energy functions and, moreover, it can provide some segmentation results unreachable by the GA method alone such as changes in the net topology.
Web Based Distributed Marine Education System
Authors: Yang Xiao, Jin Yicheng
Venue: Proceedings of the 2008 Fifth International Conference on Computer Graphics, Imaging and Visualisation (2008)

This paper presents a web based distributed marine education system. This system allow more users pursue training from anywhere and at anytime, via a PC and Web browser. It integrates the simulation to effectively makes up the limitation of traditional e-Learning, in which students tend to be restricted to a predetermined learning path through reading, listening and observation. We present the concept and characteristics of a web-based maritime simulated training environment. We design an open and strong compatible web-based three-level architectre and the function of each module. Models in virtual scene are classified and generated in VRML format. Scene data, including vertex coordinates, normal, textures, are effectively compressed and take progressive transmission strategy. Browser side implements users' dynamic interactive in virtual scene with the combining of EAI and Java Applet.
Evaluation of eigenfunctions from compound matrix variables in non-linear elasticity - II. Sixth order systems
Authors: D. M. Haughton
Venue: Journal of Computational Physics (2008)

We show how the compound matrix method can be extended to give eigenfunctions as well as eigenvalues to bifurcation problems in non-linear elasticity. The non-trivial boundary conditions create some difficulties and we find that sixth order systems for elasticity problems will require a shooting method for two functions of two unknown parameters over and above the calculations required for comparable problems in fluids.
Numerical solutions of second-order matrix models using cubic-matrix splines
Authors: M. M. Tung, E. Defez, J. Sastre
Venue: Computers Mathematics with Applications (2008)

Many studies of mechanical systems in engineering are based on second-order matrix models. This work discusses the second-order generalization of previous research on matrix differential equations dealing with the construction of approximate solutions for the initial problem Y^''(x)=f(x,Y(x),Y^'(x)) using matrix-cubic splines without any dimensional increase. An estimation of the approximation error, the corresponding algorithm of our approach and some illustrative examples are presented.
Bicriteria Approximation Tradeoff for the Node-Cost Budget Problem
Authors: Yuval Rabani, Gabriel Scalosub
Venue: Proceedings of the 11th Scandinavian workshop on Algorithm Theory (2008)

We consider an optimization problem consisting of an undirected graph, with cost and profit functions defined on all vertices. The goal is to find a connected subset of vertices with maximum total profit, whose total cost does not exceed a given budget. The best result known prior to this work guaranteed a (2,O(logn)) bicriteria approximation, i.e. the solution's profit is at least a fraction of $\frac{1}{O(\log n)}$ of an optimum solution respecting the budget, while its cost is at most twice the given budget. We improve these results and present a bicriteria tradeoff that, given any ¿ ¿ (0,1], guarantees a $(1+\varepsilon,O(\frac{1}{\varepsilon}\log n))$-approximation.
Media Synchronization Framework for SVC Video Transport over IP Networks
Authors: Kwang-Deok Seo, Jin-Won Lee, Soon-Heung Jung, Jae-Gon Kim
Venue: Proceedings of the 7th international conference on Computational Science, Part IV: ICCS 2007 (2007)

This paper proposes an efficient media synchronization framework for SVC video transport over IP networks. To support synchronization between SVC video and audio signals transported over IP networks, RTP/RTCP protocol suite is usually employed. To provide a framework for media synchronization, we suggest an efficient RTP packetization mode and propose a computationally simple RTCP packet processing method. With the suggested RTP packetization mode, layer synchronization among scalable layers of the SVC video can be effectively achieved. Also by adopting the computationally simple RTCP packet processing, we do not need to process every RTCP SR packet for inter-media synchronization between video and audio signals.
Automatic Synthesis for Quantum Circuits Using Genetic Algorithms
Authors: Cristian Ruican, Mihai Udrescu, Lucian Prodan, Mircea Vladutiu
Venue: Proceedings of the 8th international conference on Adaptive and Natural Computing Algorithms, Part I (2007)

This paper proposes an automated quantum circuit synthesis approach, using a genetic algorithm. We consider the circuit as a successive rippling of the so-called gate sections; also, the usage of a database is proposed in order to specify the gates that will be used in the synthesis process. Details are presented for an appropriate comparison with previous approaches, along with experimental results that prove the convergence and the effectiveness of the algorithm.
Joint Freehand Ultrasound and Endoscopic Reconstruction of Brain Tumors
Authors: Ruben Machucho-Cadena, Sergio Cruz-Rodríguez, Eduardo Bayro-Corrochano
Venue: Proceedings of the 13th Iberoamerican congress on Pattern Recognition: Progress in Pattern Recognition, Image Analysis and Applications (2008)

We present an approach for reconstructing the 3D shape of brain tumors for applications in neurosurgery from 2D ultrasound (US) images. We record simultaneously endoscopic and ultrasonic images, and the pose of the endoscopic camera by an optical tracking system. The 3D pose of the ultrasound probe is determined by tracking the 2D position of the ultrasound probe in successive endoscopic images by image processing techniques (Hough Transform, Particle Filtering) and finally the 3D position is computed by the known camera geometry and multiple view geometry using conformal geometric algebra. When the 3D US probe position is calculated, we compound multiple 2D US images into a 3D volume.
A Parallel Sparse Linear Solver for Nearest-Neighbor Tight-Binding Problems
Authors: Mathieu Luisier, Gerhard Klimeck, Andreas Schenk, Wolfgang Fichtner, Timothy B. Boykin
Venue: Proceedings of the 14th international Euro-Par conference on Parallel Processing (2008)

This paper describes an efficient sparse linear solver for block tri-diagonal systems arising from atomistic device simulation based on the nearest-neighbor tight-binding method. The algorithm is a parallel Gaussian elimination of blocks corresponding to atomic layers instead of single elements. It is known in the physics community as the renormalization method introduced in 1989 by Grosso et al, [Phys. Rev. B 40 12328 (1989)]. Here, we describe in details the functionality of the algorithm and we show that it is faster than direct sparse linear packages like Pardiso, MUMPS or SuperLU_DIST and that it scales well up to 512 processors.
Visualization of Shock Waves around Hypersonic Spiked Blunt Cones Using Electric Discharge
Authors: M. Viren, G. Jagadeesh, K. P. J. Reddy, M. Sun, K. Takayama
Venue: Journal of Visualization (2005)

The hypersonic flow fields around a 120&deg; apex angle blunt cone fitted with spikes have been visualized using electric discharge technique at Mach 5.75 in a hypersonic shock tunnel. The blunt cone has been fitted with a flat tipped spike and a flat aerodisc tipped spike assembly. The length of the aerodisc tipped spike assembly has been kept equal to the model base diameter (L/D=1) and the length of the flat tipped spike has been kept at 12mm. The flow field pictures reveal all the salient features of the flow fields around the spiked bodies. Numerical simulations carried out to complement the experiments agree well with the experimental pictures.
A Reproduction of Inflow Restriction in the Mock Circulatory System to Evaluate a Hydrodynamic Performance of a Ventricular Assist Device in Practical Conditions
Authors: Masateru Furusato, Tomohiro Shima, Yuma Kokuzawa, Kazuhiko Ito, Takashi Tanaka, Kiyotaka Iwasaki, Yi Qian, Mitsuo Umezu, Zhikun Yan, Ling Zhu
Venue: Proceedings of the international conference on Life System Modeling and Simulation (2007)

A novel in vitro mock circulatory system, which enables to reproduce an inflow restriction, simulating blood volume pooling due to heart failure, was developed to evaluate a hydrodynamic performance of a pulsatile ventricular assist device (VAD) in practical conditions. The concept of this development was motivated by a difference of an inflow restriction between in vitro and in vivo environments. The major idea of this study is to reproduce an inflow restriction by using a centrifugal pump placed at an inflow side of a left ventricular model instead of a constant head reservoir in a conventional circuit. In the novel circuit, the maximum flow rate was obtained at lower systolic fraction as compared with a conventional circuit. This similar tendency by the novel one was observed in an acute animal experiment in sheep. This result suggests that a new mock circuit is effective to confirm a practical drive strategy of the VAD for various diseased conditions.
Customized Predictive Models for Process Improvement Projects
Authors: Thomas Birkhölzer, Christoph Dickmann, Harald Klein, Jürgen Vaupel, Stefan Ast, Ludger Meyer
Venue: Proceedings of the 9th international conference on Product-Focused Software Process Improvement (2008)

A methodology is presented to quantitatively model the expected relationships between investments in process improvements and improvements in business measures. Such a predictive model can be used as an auxiliary in process improvement planning in addition to established models like CMMI. Different from a generic model like CMMI, the proposed methodology allows for creating a fully customized model focusing on the context or product at hand. To manage the inherent parameter uncertainty of quantitative modelling of software processes a novel approach in this context is used by explicitly handling the parameter variations using interval arithmetic. The paper outlines the methodology and presents results from a study at Siemens.