ppxscal/embedding_network huggingface dataset:
Additive Spanners for Circle Graphs and Polygonal Graphs
Authors: Feodor F. Dragan, Derek G. Corneil, Ekkehard Köhler, Yang Xiang
Venue: Graph-Theoretic Concepts in Computer Science: 34th International Workshop, WG 2008, Durham, UK, June 30 --- July 2, 2008. Revised Papers (2008)

A graph G = (V,E) is said to admit a system of μ collective additive tree r-spanners if there is a system $\cal{T}$(G) of at most μ spanning trees of G such that for any two vertices u,v of G a spanning tree $T\in \cal{T}$(G) exists such that the distance in T between u and v is at most r plus their distance in G. In this paper, we examine the problem of finding "small" systems of collective additive tree r-spanners for small values of r on circle graphs and on polygonal graphs. Among other results, we show that every n-vertex circle graph admits a system of at most $2\log_{\frac{3}{2}}n$ collective additive tree 2-spanners and every n-vertex k-polygonal graph admits a system of at most $2\log_{\frac{3}{2}}k+7$ collective additive tree 2-spanners. Moreover, we show that every n-vertex k-polygonal graph admits an additive (k + 6)-spanner with at most 6n ¿ 6 edges and every n-vertex 3-polygonal graph admits a system of at most 3 collective additive tree 2-spanners and an additive tree 6-spanner. All our collective tree spanners as well as all sparse spanners are constructible in polynomial time.
Occlusion Boundaries from Motion: Low-Level Detection and Mid-Level Reasoning
Authors: Andrew N. Stein, Martial Hebert
Venue: International Journal of Computer Vision (2009)

The boundaries of objects in an image are often considered a nuisance to be "handled" due to the occlusion they exhibit. Since most, if not all, computer vision techniques aggregate information spatially within a scene, information spanning these boundaries, and therefore from different physical surfaces, is invariably and erroneously considered together. In addition, these boundaries convey important perceptual information about 3D scene structure and shape. Consequently, their identification can benefit many different computer vision pursuits, from low-level processing techniques to high-level reasoning tasks.While much focus in computer vision is placed on the processing of individual, static images, many applications actually offer video, or sequences of images, as input. The extra temporal dimension of the data allows the motion of the camera or the scene to be used in processing. In this paper, we focus on the exploitation of subtle relative-motion cues present at occlusion boundaries. When combined with more standard appearance information, we demonstrate these cues' utility in detecting occlusion boundaries locally. We also present a novel, mid-level model for reasoning more globally about object boundaries and propagating such local information to extract improved, extended boundaries.
How to Choose Basis Functions in Meshless Methods?
Authors: Vratislava Mošová
Venue: Numerical Analysis and Its Applications: 4th International Conference, NAA 2008, Lozenetz, Bulgaria, June 16-20, 2008. Revised Selected Papers (2009)

Technical progress in construction of computers, their higher speed, and larger memory gave possibility to develop new numerical methods for solution of boundary value problems. A lot of meshless methods have been developed in last years. Some of them are in a way identical with the Galerkin method, where the trial space is formed by especially constructed functions. The choice of the proper trial space is important, because the error in the Galerkin method is determined by the fact how well the exact solution can be approximated by the elements from this finite dimensional space.In this contribution different trial spaces are considered. We will construct spaces generated by means of B-splines and shape functions received by means of the RKP technique. Examples of using trial spaces mentioned for solution of some boundary value problems will be given. We focus our attention on error estimates in these cases too.
How Applicable is Your Evaluation Methods - Really? Analysis and Re-design of Evaluation Methods for Fun and Entertainment
Authors: Charlotte Wiberg, Kalle Jegers, Heather Desurvire
Venue: Proceedings of the 2009 Second International Conferences on Advances in Computer-Human Interactions (2009)

This paper presents an approach to analyze and re-design evaluation methods. The domain explored in this paper is evaluation methods for evaluating fun and entertainment. However, the approach presented may be applied in other domains as well. The approach is conceptually described and two examples of processes where the approach were used in practice are further discussed. As the map of IT applications and digital media is continuously re-designed, there is a constant need of re-designing evaluation methods.
A HyperTransport 3 Physical Layer Interface for FPGAs
Authors: Heiner Litz, Holger Froening, Ulrich Bruening
Venue: Proceedings of the 5th International Workshop on Reconfigurable Computing: Architectures, Tools and Applications (2009)

This paper presents the very first implementation of a HyperTransport 3 physical layer interface for Field Programmable Gate Arrays. HyperTransport is a low latency, high bandwidth point-to-point interconnect technology that can be used to directly connect hardware accelerators to AMD's Opteron CPUs. Providing support for HyperTransport 3 on FPGAs is highly relevant for increasing the performance of accelerators based on reconfigurable logic. This paper shows the challenges of such an implementation and novel ideas to solve them successfully. A new architecture is presented that uses Fast Serializer Logic to keep up with the increasing speeds of current host interface protocols. A solid evaluation is provided using a specially developed FPGA board as a verification platform.
Finite difference time domain algorithm for electromagnetic problems involving material movement
Authors: C. D. Sijoy, Shashank Chaturvedi
Venue: Journal of Computational Physics (2009)

The finite difference time domain (FDTD) method, adapted for magnetic field diffusion problems, is used to study the electromagnetic induction in moving materials by including motional emf in standard FDTD electromagnetic equations. The material movement is implemented by continuously changing material properties in each computational cell consistent to material advection. The flux corrected transport (FCT) algorithm is used to transport magnetic field in a fixed eulerian cell. A higher time-step is achieved by artificially increasing permittivity of the medium. This new approach is validated with standard analytical solutions for planar magnetic flux compression system and magnetic field diffusion in moving conductors with a non-relativistic velocity. To our knowledge, this is the first approach to use FDTD method for electromagnetic problems involving material motion.
A New Optimization Scheme for Resource Allocation in OFDMA Based WiMAX Systems
Authors: Arijit Ukil, Jaydip Sen, Debasish Bera
Venue: Proceedings of the 2009 International Conference on Computer Engineering and Technology - Volume 01 (2009)

In this paper, an efficient scheme to optimize resource allocation for dynamic OFDMA based WiMAX systems is presented, which provides priority estimated resource allocation with individual QoS provisioning. Our proposed scheme dynamically assigns OFDMA resources to the users to optimize the overall system performance in heterogeneous traffic and diverse QoS based WiMAX systems. To achieve this goal, we have introduced priority indexed long-term (PILTPF) resource allocation algorithm, which dynamically allocates the OFDMA resources to the users to meet their QoS requirement, which is dependent on user’s derived priority profile. It also considers the time diversity gain achieved in long-term computation of Proportional Fair (PF) metric. PILTPF algorithm emphasizes on individual user’s true priority in allocating system resources in order to maintain as well as optimize the requirements of different QoS classes, existing in the current and next generation broadband wireless networks like WiMAX. Simulation results show considerable improvement of performance due to priority based resource allocation with long term PF calculation with respect to traditional PF algorithm.
Green Computing: Energy Consumption Optimized Service Hosting
Authors: Walter Binder, Niranjan Suri
Venue: Proceedings of the 35th Conference on Current Trends in Theory and Practice of Computer Science (2009)

Green Computing is a recent trend towards designing, building, and operating computer systems to be energy efficient. While programs such as Energy Star have been around since the early 1990s, recent concerns regarding global climate change and the energy crisis have led to renewed interest in Green Computing. Data centers are a significant consumers of energy - both to power the computers as well as to provide the necessary cooling. This paper proposes a new approach to reduce energy utilization in data centers. In particular, our approach relies on consolidating services dynamically onto a subset of the available servers and temporarily shutting down servers in order to conserve energy. We present initial work on a probabilistic service dispatch algorithm that aims at minimizing the number of running servers such that they suffice for meeting the quality of service required by service-level agreements. Given the estimated energy consumption and projected growth in data centers, the proposed effort has the potential to positively impact energy consumption.
JCL-Step by Step
Authors: Andrew Robert Chapman
Venue:  (2008)

Job Entry System Job Control Language, or more simply JES JCL, is almost as old as the original IBM System/360 mainframes for which it was written, and over recent years hasn't evolved all that much. But why should something evolve, when it is already highly effective at doing what it was designed for? Most programmers and operators may scoff at this statement, but then again most programmers and operators code JCL badly.This book dismantles the woefully common and typical style of programming JCL, and introduces methods for the production of highly maintainable, analysis friendly application jobs. Ways in which JCL and job architecture can be constructed, and how the features of JES2 can be combined to form a modern and efficient infrastructure. The book contains many generic procedure examples drawn from the real world, and details logic, include and procedure members, variables, semaphores, dynamic JCL, out of control execution and much more.A must have handbook for any technician whose job is associated with JCL programming, the accompanying software is available at www.arcware-ltd.de.A few years after graduating with a BSc Honours Degree in Computing Science the author moved from his native England to Germany in 1991, where he is currently the Managing Director of a specialised software company which focuses on the optimisation of legacy z/OS systems written in COBOL and Assembler, and controlled with JES2 JCL. He has also written Cobol: Optimised and Maintainable Application Programming (ISBN-13: 978-0595432592).
Issues in the development of natural language front-ends
Authors: James Hendler, Thomas P. Kehler, Paul Roller Michaelis, Brian Phillips, Kenneth M. Ross, Harry R. Tennant
Venue: Proceedings of the May 4-7, 1981, national computer conference (1981)

This paper will discuss some issues we believe to be important to the design of a natural language front-end. These are divided into three categories: conceptual coverage, linguistic coverage, and implementation issues. The section on conceptual coverage discusses the use of a domain expert, which understands what the user is saying even though the system to which the front-end is interfaced might not be able to properly do what the user wants. The section on linguistic coverage discusses attempts to allow a natural language interface to handle natural, interactive human communication. Two solutions are explored: First, the design of a robust natural-language-understanding system, composed of many experts that know about some aspect of the organization of language, is considered; second, because the design of a robust system is a large task, the intermediate goal of limiting the vocabulary and constructions that can be used while retaining all the user-oriented benefits of natural language is considered. The implementation issues considered are the design of a system in which the grammar and the domain of discourse can be easily extended and which can be used for more than one domain without extensive rewrite.
Uniqueness of positive solutions for Neumann problems in unbounded domain
Authors: Wei Dong, Nianpeng Wang, Chenghua Dang
Venue: WSEAS Transactions on Mathematics (2008)

In this paper, we consider the existence and uniqueness positive solutions of the following boundary Neumann problem. -Δu=a(x)u - b(x)f(u) x ∈ T, ∂u/∂n = 0, on ∂T, where T ={x=(x1,x2,...,xN): xN > 0}, (N ≥ 2), a(x) and b(x) are continuous functions with b(x) positive on RN and n is outward pointing unit normal vector of ∂T, we show that under rather general conditions on a(x) and b(x) for large | x | and f(u) behaves like uq, where constant q > 1, the above problems possesses a minimal positive solution and a maximal positive solution, respectively, Moreover, we establish a relationship between the above problem and the following problem -Δu = a(x)u - b(x)f(u) x ∈ RN, We establish a comparison principal which our proof of the existence results rely essentially on. and make use of a rather intuitive squeezing method to get the existence theorems. Furthermore, by analyzing the behavior of the positive solution for the problem in whole space, we show the boundary Neumann problem in half space has only one positive solution. Our results improve the previous works.
TOA estimation for UWB through-wall application
Authors: Ma Lin, Zhang Zhongzhao, Tan Xuezhi
Venue: Proceedings of the 2008 International Conference on Advanced Infocomm Technology (2008)

The wall filter effect on the UWB through-wall impulse is investigated. The problem addressed is the TOA estimation error for the UWB indoor application. Simulation and analysis point out that it is advisable to employ the proper impulse to achieve the high time resolution rather than to employ the impulse as short as possible. The high time resolution and distortion by wall filter effect should be trade off and well considered when the impulse is chosen for the through-wall application. The shorter through-wall impulse it is, the greater distortion it suffers. For templates mismatching with the received signal, the receiver estimates the wrong TOA against the peak of the correlation. The proposed solution is to modify the template according to the application scenarios for different wall materials. Mathematical analysis is exploited to show the validity of this method.
A streamline diffusion method for a singularly perturbed conservative convection-diffusion problem
Authors: Zhongdi Cen, Lifeng Xi
Venue: Proceedings of the 3rd WSEAS international conference on Computer engineering and applications (2009)

In this paper we apply a streamline diffusion finite element method (SDFEM) to a singularly perturbed conservative convection-diffusion problem. The stability and accuracy of the SDFEM on arbitrary grids are studied. We derive the pointwise error estimates and the approximation of derivatives. Numerical experiments support our theoretical results.
Optimal Placement of Detection Nodes against Distributed Denial of Service Attack
Authors: Muhammad Hasan Islam, Kamran Nadeem, Shoab A. Khan
Venue: Proceedings of the 2009 International Conference on Advanced Computer Control (2009)

Distributed denial of service (DDoS) attacks have become a major threat to organizations and especially to internet and intranet. In DDoS attacks targets are overwhelmed by sending an enormous amount of traffic from a number of attack sites. The major tasks of any defense system are to detect these attacks accurately and early on, before it causes an unrecoverable loss. Most of the research in this regard has been focused on the detection techniques without exploiting spatial placement of detection system in a network. The ideal way to completely eliminate the DDoS threat is to run detection mechanism on every node in the network, which is not a practical solution. In this paper, we focus on the optimized placement of detection nodes in a network for distributed detection of DDoS attacks, which not only minimize the number of these node required but also reduce the cost, processing overheads and larger delays in identifying an attack. We examine the placement problem of finding a minimum cardinality set of nodes to detect DDoS attacks such that no attack traffic can reach the target without being monitored by these sensors. The placement problem is formulated as set packing.
Utilizing Multi-Agent Modelling to Develope Urban Simulations
Authors: Jinfeng Ma, Feng Mao, Wensheng Zhou
Venue: Proceedings of the 2009 International Asia Conference on Informatics in Control, Automation and Robotics (2009)

Cities are faced with many problems such as urban sprawl, congestion, and segregation. They are constantly changing. The heterogeneous nature of cities, make it difficult to generalize localized problems from that of city-wide problems. Computer modeling is becoming an increasingly important tool when examining how cities operate. Agent-based models allow for testing of different hypotheses and theories for urban changes, thus leading to a greater understanding of how cities work. This paper propose a multi-agents systems/simulation model based on integration among parallel processing, coupling with vector GIS,temporal logic analysis and the integration with the rule engine. The efficiency of our approach is shown through some experimental results, which highlights how different theories can be incorporated into one model and demonstrates how the well-known principle that local action can give rise to global pattern but also how such pattern emerges as the consequence of positive feedback and learned behavior.
Aspects of quality assurance in medical devices production
Authors: Luciana Cristea, Mihaela Baritz, Diana Cotoros, Angela Repanovici
Venue: Proceedings of the 8th conference on Signal processing, computational geometry and artificial vision (2008)

The control methods used for medical devices parts have to secure the accomplishment of the special conditions required by the characteristics of the measuring (some slight measuring errors, narrow measuring field, and diminished tolerance zone). Taking into account these characteristics, as far as the medical devices industry is concerned, in this paper are analyzed so-called classical methods (with contact), as well as methods with no contact (optical).
A recommendation method considering users' time series contexts
Authors: Kenta Oku, Shinsuke Nakajima, Jun Miyazaki, Shunsuke Uemura, Hirokazu Kato
Venue: Proceedings of the 3rd International Conference on Ubiquitous Information Management and Communication (2009)

This paper proposes a recommendation method considering users' time series contexts which are situations that have occurred / will occur in the past/future. There are some recommendation methods that provide information suitable for users' action patterns as the recommendation methods considering them. These methods provide information referring to the other users that have a similar action pattern to that of an active user. However, since a user's action pattern changes depending on the user's contexts, the methods need to refer to the other users' action patterns related to the current user's contexts. In this paper, we propose a recommendation method considering the user's time series contexts considering that the user's action pattern changes depending on the user's contexts.
Curves with chord length parameterization
Authors: Wei Lü
Venue: Computer Aided Geometric Design (2009)

Motivated by the recent work (Farin, G., 2006. Rational quadratic circles are parameterized by chord length, Computer Aided Geometric Design 23, 722-724), we identify a family of curves that can be parameterized by chord length. The @a- and (@a,@b)-schemes are presented for characterizing planar and spatial curves respectively. Rational chord-length parameterizations are thoroughly investigated. In particular, the low-degree rational curves such as cubics and quartics are studied and applied to geometric Hermite interpolation. The results advise that this new class of curves, subsuming straight lines and circular arcs, have several obvious advantages over general polynomial and rational curves.
Automatic contour model creation out of polygonal CAD models for markerless Augmented Reality
Authors: Juri Platonov, Marion Langer
Venue: Proceedings of the 2007 6th IEEE and ACM International Symposium on Mixed and Augmented Reality (2007)

We present a solution for automatic extraction of contour models out of polygonal CAD models. Such contour models can be used for markerless initialization and tracking purposes. To create a contour model we synthesize different views of the object using its CAD model. During the view generation we alternate the camera pose as well as light conditions in order to extract the most stable contours in terms of illumination invariance and view independence. We project the extracted 2D edges back into the 3D space and accumulate for every 3D point statistics over different views describing its visibility and stability under different illumination conditions. After filtering out all 3D points with probability below a certain threshold value we use the Euclidean Minimum Spanning Tree algorithm to get the connected contours out of the 3D point cloud. The result is a B-Spline or VRML representation of the most stable contours.
Optimal strong (κ,d)-orientation of complete k-partite graphs
Authors: Huifang Miao, Xiaofeng Guo
Venue: Discrete Applied Mathematics (2009)

For two vertices u and v in a strong oriented graph D, the strong distance sd(u,v) between u and v is the minimum size (the number of arcs) of a strong sub-digraph of D containing u and v. For a vertex v of D, the strong eccentricity se(v) is the strong distance between v and a vertex farthest from v. The strong diameter sdiam(D) is the maximum strong eccentricity among the vertices of D. The lower orientable strong diameter sdiam(G) of a graph G is the minimum strong diameter over all strong orientations of G. An orientation D of a graph G is said to be an optimal strong (@k,d)-orientation of G if @k(D)=@?@k(G)/2@? and sdiam(D)=sdiam(G), where @k(D) (resp. @k(G)) is the strong connectivity of D (resp. connectivity of G). In this paper, we will show that each complete k-partite graph has an optimal strong (@k,d)-orientation.
A Novel Multi-channel Multi-radio Wireless Mesh Node Architecture for NS-2
Authors: MyungIn Ji, Yonggyu Kim, Myunghwan Seo, Joongsoo Ma
Venue: Proceedings of the 2009 WRI International Conference on Communications and Mobile Computing - Volume 02 (2009)

In this paper, we propose new network simulator architecture to simulate the performance of multi-channel multi-radio mesh network in the NS-2. We add Multi-radio abstraction layer to manage multiple radio instances, and we are able to simulate regardless of the number of channels and radios in each node. Most of all, we implement some important procedures for realistic multi-channel multi-radio experiments such as channel switching mechanism and multiple radio usage policy. Using this architecture, we evaluate the performance when all of nodes utilize 3 radios according to the number of available channels. Simulation results show that the performance can be improved up to 2.15 times compared to using 2 radios.