ppxscal/embedding_network huggingface dataset:
The analysis of Nash equilibria of the one-shot random-access game for wireless networks and the behavior of selfish nodes
Authors: Hazer Inaltekin, Stephen B. Wicker
Venue: IEEE/ACM Transactions on Networking (TON) (2008)

We address the fundamental question of whether or not there exist stable operating points in a network in which selfish nodes share a common channel, and if they exist, how the nodes behave at these stable operating points. We begin with a wireless communication network in which n nodes (agents), which might have different utility functions, contend for access on a common, wireless communication channel. We characterize this distributed multiple-access problem in terms of a one-shot random-access game, and then analyze the behavior of the nodes using the tools of game theory. We give necessary and sufficient conditions on nodes for the complete characterization of the Nash equilibria of this game for all n ≥ 2. We show that all centrally controlled optimal solutions are a subset of this game theoretic solution, and almost all (w.r.t. Lebesgue measure) transmission probability assignments chosen by a central authority are supported by the game theoretic solution. We analyze the behavior of the network throughput at Nash equilibria as a function of the costs of the transmitters incurred by failed transmissions. Finally, we conclude the paper with the asymptotic analysis of the system as the number of transmitters goes to infinity. We show that the asymptotic distribution of the packet arrivals converges in distribution to a Poisson random variable, and the channel throughput converges to - (c/ (1 + c)) In (c/ (1 + c)) with c > 0 being the cost of failed transmissions. We also give the best possible bounds on the rates of convergence of the packet arrival distribution and the channel throughput.
Graph sketcher: extending illustration to quantitative graphs
Authors: Robin Stewart, m.c. schraefel
Venue: Proceedings of the 27th international conference on Human factors in computing systems (2009)

Scientists, engineers, and educators commonly need to make graphs that quickly illustrate quantitative ideas yet are not based on specific data sets. We call these graphs quantitative concept diagrams (QCDs). Existing charting and illustration programs make it possible to produce such graphs, but they are so time-consuming that users tend to sketch the graphs by hand instead. To reduce the cost of creating QCDs, we developed Graph Sketcher, a quantitative graphing tool that deeply integrates the data plotting capabilities of charting programs with the direct manipulation techniques of illustration programs. We show that our integrated interface substantially reduces the time needed to create QCDs, and we further show that real Graph Sketcher users both enjoy and take advantage of the interface improvements to create QCDs in a wide range of fields.
Hiding the complexity of LBS
Authors: Matthias Böhmer, Gernot Bauer, Wolfgang Wicht
Venue: Proceedings of the 2nd International Workshop on Location and the Web (2009)

While the demand for Location-based Services (LBS) is strongly increasing, technical laymen are not yet able to build and provide location-aware applications. This paper presents a radical simplification of the lifecycle of LBSs. An authoring toolkit enables non-technicians to easily develop context-aware mobile applications. In addition, an adaptive user interface makes the consumption of LBSs easier. The platform we present, in covering the whole LBS supply chain, is hiding the complexity of providing and consuming LBSs from the end-users.
Distraxion
Authors: Mike Stern
Venue: ACM SIGGRAPH ASIA 2008 computer animation festival (2008)

"Distraxion" is a computer-animated narrative film that relies on traditional storytelling and animation principles. The film represents a successful creator-driven project as well as an accomplishment in the field of online animation education. The majority of the film was developed during the short film curriculum at the online school animationmentor.com. It was then polished by the individual artists working remotely over the course of the following year.
Automated test data generation for aspect-oriented programs
Authors: Mark Harman, Fayezin Islam, Tao Xie, Stefan Wappler
Venue: Proceedings of the 8th ACM international conference on Aspect-oriented software development (2009)

Despite the upsurge of interest in the Aspect-Oriented Programming (AOP) paradigm, there remain few results on test data generation techniques for AOP. Furthermore, there is no work on search-based optimization for test data generation, an approach that has been shown to be successful in other programming paradigms. In this paper, we introduce a search-based optimization approach to automated test data generation for structural coverage of AOP systems. We present the results of an empirical study that demonstrates the effectiveness of the approach. We also introduce a domain reduction approach for AOP testing and show that this approach not only reduces test effort, but also increases test effectiveness. This finding is significant, because similar studies for non-AOP programming paradigms show no such improvement in effectiveness, merely a reduction in effort. We also present the results of an empirical study of the reduction in test effort achieved by focusing specifically on branches inside aspects.
Cause effect graph to decision table generation
Authors: Praveen Ranjan Srivastava, Parshad Patel, Siddharth Chatrola
Venue: ACM SIGSOFT Software Engineering Notes (2009)

Cause-Effect Graphing (CEG) is used to identify test cases from a given specification to validate its corresponding implementation. This paper gives detail about this technique of software testing. It also shows how the CEG technique can be used to test that software fulfill requirement specification or not. This paper surveys how CEG converted into decision table. The aim of this paper is to overcome existing algorithm's shortcomings and generate all possible test cases.
Multithreaded Hybrid Feature Tracking for Markerless Augmented Reality
Authors: Taehee Lee, Tobias Höllerer
Venue: IEEE Transactions on Visualization and Computer Graphics (2009)

We describe a novel markerless camera tracking approach and user interaction methodology for augmented reality (AR) on unprepared tabletop environments. We propose a real-time system architecture that combines two types of feature tracking. Distinctive image features of the scene are detected and tracked frame-to-frame by computing optical flow. In order to achieve real-time performance, multiple operations are processed in a synchronized multi-threaded manner: capturing a video frame, tracking features using optical flow, detecting distinctive invariant features, and rendering an output frame. We also introduce user interaction methodology for establishing a global coordinate system and for placing virtual objects in the AR environment by tracking a user's outstretched hand and estimating a camera pose relative to it. We evaluate the speed and accuracy of our hybrid feature tracking approach, and demonstrate a proof-of-concept application for enabling AR in unprepared tabletop environments, using bare hands for interaction.
Analyzing and optimizing energy efficiency of algorithms on DVS systems a first step towards algorithmic energy minimization
Authors: Tetsuo Yokoyama, Gang Zeng, Hiroyuki Tomiyama, Hiroaki Takada
Venue: Proceedings of the 2009 Asia and South Pacific Design Automation Conference (2009)

The energy efficiency at the algorithmic level on DVS systems and its analysis and optimization methods are presented. Given a problem the most energy efficient algorithm is not uniquely determined but dependent on multiple factors, including intratask dynamic voltage scaling (IntraDVS) policies, the size of intermediate data structure, and the size of inputs. We show that at the algorithmic level principles behind energy optimization and performance optimization are not identical. We propose a metric for evaluating optimal energy efficiency of static voltage scaling (SVS) and a few new effective IntraDVS policies employing data flow information. Experimental results on sorting algorithms show the existence of several tradeoffs in terms of energy consumption. Transforming algorithms by employing problem specific knowledge and data flow information successfully improves their energy efficiency.
GVP model based temporal visualisation of user-centric data
Authors: T. Mala, P. Bhargavi, T. V. Geetha
Venue: International Journal of Metadata, Semantics and Ontologies (2008)

Information that can be transformed to visual form is of various types, and here it is proposed to develop a system that performs temporal visualisation of a user's personal interest information. The system performs visualisation of the user's profile recorded automatically from his browsing interest and visualises the search results of a search query which is a temporal data by applying the identified personalised user profile. Thus the system performs a user-centric temporal visualisation based on a novel Gestalt Visual Perception model (GVP model) as it focuses on a user's personal interest that changes over a period of time.
From eLearning to eUniversity
Authors: Roumen Nikolov
Venue: Proceedings of the 9th International Conference on Computer Systems and Technologies and Workshop for PhD Students in Computing (2008)

This paper analyses the specifics and the tendencies in building the knowledge society as well as the role of the universities in this process. Some European policies and programs dedicated to the new role of the universities in realizing the Lisbon Strategy are analysed as well. It is emphasized on the importance of integration of the 'knowledge triangle' (education, research and innovation) into a research university and on the urgent need to re-design the university activities according to the new requirements. A model of eUniversity is defined as a research and entrepreneurial university which integrates ICT in all university activities, including the ones related to the outside knowledge intensive organisations. The paper describes also some real experiences, emerging models and lessons learnt based on the case of Software Engineering education and research at Sofia University.
New cryptosystems design based on hybrid-mode problems
Authors: Pin-Chang Su, Chien-Hua Tsai
Venue: Computers and Electrical Engineering (2009)

Though a lot of public key cryptographic algorithms have been proposed, practically some cryptographic systems' security will no longer be secure unless the corresponding hard problems are solved in the future. Enhancing security is the major objective for public key cryptosystems on the basis of the hardness of the intractable computational problems. In this paper, we present a new cryptosystem design based on linearly shift knapsack and elliptic curve discrete logarithm problems. Having concatenated Knapsack and ECC hard problems, the presented scheme has solid structure and will hopelessly leave the eavesdropper baffled. The performance analysis has been given to describe the proposed scheme in terms of security level. In addition, the security performance in encryption/decryption complexity is equivalent to related cryptosystems with the nature of security. At the moment, no malicious attacks are capable of ''breaking'' this scheme in a reasonable amount of time obviously.
Performance evaluation of GPON vs EPON for multi-service access
Authors: T. Orphanoudakis, H.-C. Leligou, E. Kosmatos, J. D. Angelopoulos
Venue: International Journal of Communication Systems (2009)

Recently both ITU and IEEE have standardized solutions for passive optical networks (PONs) operating at gigabit per second line rates and optimized for the transport of packet-based traffic to improve the efficiency of previously standardized broadband PONs, which used the ATM cell as the data transport unit. The efficiency and performance of PON systems depend on the transmission convergence layer and mainly on the implemented medium access protocol. Although the latter is not part of the standards and left to the implementer, the standards describe a set of control fields that constitute the tool-set for the media access control (MAC) operation. Though starting from a common and quite obvious basis, the two standards present significant differences with the legacy of Ethernet marking the IEEE approach, while the emphasis of ITU is on demanding services. In this paper we compare the efficiency and performance of the two systems assuming the implementation of as close as possible MAC protocols. The target is twofold: assess and compare the traffic handling potential of each of the two standards and identify the range of applications they can support. Useful insight can also be gained to the MAC tools that could be designed into the next generation extra large WDM PONs. Copyright &copy; 2008 John Wiley & Sons, Ltd.
Development of an Ansys interface for FE solid modeling and analysis of corroded pipelines
Authors: Rita C. C. Silva, João N. C. Guerreiro, Patrícia R. C. Drach
Venue: Proceedings of the 8th conference on Applied computer scince (2008)

The assessment of the structural integrity of corroded pipes has become of main interest to help engineers to take the important decision of maintaining or repairing a pipeline. Solid finite element (FE) models have been widely used to perform failure analyses but the generation of the required models is, in many cases, a hard task to do. In this work, we present the PIPE program that provides an Ansys Interface to automatically generate solid models and to manage the FE analyses of pipes with multiple rectangular defects in arbitrary position. The code is totally developed within the general-purpose program Ansys and the whole process is guided by a friendly interface. A validation test comparing the experimental to the numerical results is presented.
An improved smart card based password authentication scheme with provable security
Authors: Jing Xu, Wen-Tao Zhu, Deng-Guo Feng
Venue: Computer Standards Interfaces (2009)

Password authentication has been adopted as one of the most commonly used solutions in network environment to protect resources from unauthorized access. Recently, Lee-Kim-Yoo [S.W. Lee, H.S. Kim, K.Y. Yoo, Improvement of Chien et al.'s remote user authentication scheme using smart cards, Computer Standards & Interfaces 27 (2) (2005) 181-183] and Lee-Chiu [N.Y. Lee, Y.C. Chiu, Improved remote authentication scheme with smart card, Computer Standards & Interfaces 27 (2) (2005) 177-180] respectively proposed a smart card based password authentication scheme. We show that these two schemes are both subject to forgery attacks provided that the information stored in the smart card is disclosed by the adversary. We also propose an improved scheme with formal security proof.
Comparing Gesture and Touch for Notification System Interactions
Authors: Maria Karam, Jason Chong Lee, Travis Rose, Francis Quek, Scott McCrickard
Venue: Proceedings of the 2009 Second International Conferences on Advances in Computer-Human Interactions (2009)

We explore some of the characteristics of multimodal input interaction spaces for notification systems within a multi-tasking environment like a command and control center using two promising interaction methods: gestures and touch based input through a laboratory experiment comparing both techniques. Results of our study suggest that gestures are better suited for multi-tasking situations because they are less interruptive than touch interaction to users' primary tasks and are subjectively preferred by users in certain situations.
Three Dimensional Geological Modeling from Component-based Topological Data Model
Authors: Zhou Zhao, En-ke Hou, Zhi-hua Zhang, Nian-dong Deng
Venue: Proceedings of the 2009 International Conference on Computer Modeling and Simulation (2009)

Three-dimensional geological modeling (3DGM) is a complicated project in the research of the three-dimensional geographic information system, and there have many data model for the geological modeling by now. The thesis introduces a kind of object-oriented data model: the Component-based Topological Data Model (CTDM). Based on the modeling principles analysis, the author discusses and gives out the modeling steps, especially on the spatial section location, coordinates conversion, Component definition and the geological volume representation from this data model. In the end of the paper, an example was completed by the primal system for geological modeling, which was accomplished by using the CTDM.
Web robot detection: A probabilistic reasoning approach
Authors: Athena Stassopoulou, Marios D. Dikaiakos
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2009)

In this paper, we introduce a probabilistic modeling approach for addressing the problem of Web robot detection from Web-server access logs. More specifically, we construct a Bayesian network that classifies automatically access log sessions as being crawler- or human-induced, by combining various pieces of evidence proven to characterize crawler and human behavior. Our approach uses an adaptive-threshold technique to extract Web sessions from access logs. Then, we apply machine learning techniques to determine the parameters of the probabilistic model. The resulting classification is based on the maximum posterior probability of all classes given the available evidence. We apply our method to real Web-server logs and obtain results that demonstrate the robustness and effectiveness of probabilistic reasoning for crawler detection.
High-performance sharing of consistent data in ad hoc networks
Authors: F. J. Knaesel, M. A. R. Dantas
Venue: International Journal of Networking and Virtual Organisations (2009)

In mobile wireless environments, Personal Digital Assistants (PDAs) may cache data to work, even when the mobile client is far from the structured network. However, the same cached data may be shared by two or more users and this can be done in an ad hoc wireless network. In this case, it is necessary to always have the most updated data. To solve this problem, we developed software that shares data between the server and mobile devices using a timestamp protocol to always have the most updated data. The experimental environment has one server in a structured network and two mobile clients getting and sending data between the client and the server (when it is covered by the structured wireless network) and between the mobile clients (when a structured wireless network is absent) using an ad hoc network. In this paper, we describe the experimental environment and detail what and how we have done this software.
Telecommunications Feature Subscription as a Partial Order Constraint Problem
Authors: Michael Codish, Vitaly Lagoon, Peter J. Stuckey
Venue: Proceedings of the 24th International Conference on Logic Programming (2008)

This paper describes the application of a partial order constraint solver to a telecommunications feature subscription configuration problem. Partial order constraints are encoded to propositional logic and solved using a state-of-the-art Boolean satisfaction solver. The encoding is based on a symbol-based approach: symbols are viewed as variables which take integer values and are interpreted as indices in the order. Experimental evaluation indicates that partial order constraints are a viable alternative to previous solutions which apply constraint programming techniques and integer linear programming.
Error Analysis in Homography Estimation by First Order Approximation Tools: A General Technique
Authors: Pei Chen, David Suter
Venue: Journal of Mathematical Imaging and Vision (2009)

This paper shows how to analytically calculate the statistical properties of the errors in estimated parameters. The basic tools to achieve this aim include first order approximation/perturbation techniques, such as matrix perturbation theory and Taylor Series. This analysis applies for a general class of parameter estimation problems that can be abstracted as a linear (or linearized) homogeneous equation.Of course there may be many reasons why one might which to have such estimates. Here, we concentrate on the situation where one might use the estimated parameters to carry out some further statistical fitting or (optimal) refinement. In order to make the problem concrete, we take homography estimation as a specific problem. In particular, we show how the derived statistical errors in the homography coefficients, allow improved approaches to refining these coefficients through subspace constrained homography estimation (Chen and Suter in Int. J. Comput. Vis. 2008).Indeed, having derived the statistical properties of the errors in the homography coefficients, before subspace constrained refinement, we do two things: we verify the correctness through statistical simulations but we also show how to use the knowledge of the errors to improve the subspace based refinement stage. Comparison with the straightforward subspace refinement approach (without taking into account the statistical properties of the homography coefficients) shows that our statistical characterization of these errors is both correct and useful.
Local edge colouring of Yao-like subgraphs of Unit Disk Graphs
Authors: J. Czyzowicz, S. Dobrev, E. Kranakis, J. Opatrny, J. Urrutia
Venue: Theoretical Computer Science (2009)

The focus of the present paper is on providing a local deterministic algorithm for colouring the edges of Yao-like subgraphs of Unit Disk Graphs. These are geometric graphs such that for some positive integers l,k the following property holds at each node v: if we partition the unit circle centered at v into 2k equally sized wedges then each wedge can contain at most l points different from v. We assume that the nodes are location aware, i.e. they know their Cartesian coordinates in the plane. The algorithm presented is local in the sense that each node can receive information emanating only from nodes which are at most a constant (depending on k and l, but not on the size of the graph) number of hops (measured in the original underlying Unit Disk Graph) away from it, and hence the algorithm terminates in a constant number of steps. The number of colours used is 2kl+1 and this is optimal for local algorithms (since the maximal degree is 2kl and a colouring with 2kl colours can only be constructed by a global algorithm), thus showing that in this class of graphs the price for locality is only one additional colour.
A new smoothing strategy for computing nearly singular integrals in 3D Galerkin BEM
Authors: Letizia Scuderi
Venue: Journal of Computational and Applied Mathematics (2009)

In this paper we propose an efficient strategy to compute nearly singular integrals over planar triangles in R^3, arising in 3D Galerkin BEM. The strategy is based on a proper use of various nonlinear transformations, which smooth, or move away or quite eliminate all the singularities close to the domain of integration. We will deal with near singularities of the form 1/r and 1/r^3, r=@?x-y@? being the distance between two generic points x and y lying on triangles which are disjoint, but very close to each other. The approach proposed here is demonstrated by numerical experiments.