ppxscal/embedding_network huggingface dataset:
Efficient security policy enforcement for the mobile environment
Authors: Vijayalakshmi Atluri, Heechang Shin, Jaideep Vaidya
Venue: Journal of Computer Security (2008)

In the last decade, mobile communication has enjoyed unprecedented growth all over the world. The recent advances in mobile communication technologies including Global Positioning System (GPS) and Radio Frequency Identification (RFID) have propelled the growth of a number of mobile services. Typically, these require maintaining the mobile objects' location and profile information and efficiently serving access requests on the past, present and future status of the moving objects. This creates inherent security and privacy challenges. One solution to this is to specify security policies to ensure controlled access. However, this significantly degrades system performance. To alleviate this, Atluri and Guo have proposed an unified index structure, STPR-tree, to organize both the moving objects and authorizations specified over them. A significant limitation of this approach is that it is unable to store past location information of objects and is therefore not capable of supporting security policies based on tracking of mobile users. In this paper, we propose a new unified index structure, called the S PPF-tree, which maintains past, present and future positions of the moving objects along with authorizations by employing partial persistent storage. Besides demonstrating how the S PPF-tree can be constructed and maintained, we provide algorithms to process queries where either the subject or the object or both are mobile. We provide a comprehensive experimental evaluation to establish the scalability and performance of our approach.
Preventing DDoS Attacks Based on Credit Model for P2P Streaming System
Authors: Jun Yang, Ying Li, Benxiong Huang, Jiuqiang Ming
Venue: Proceedings of the 5th international conference on Autonomic and Trusted Computing (2008)

Distributed Denial of Service (DDoS) attack is a serious threat to the Internet communications especially to P2P streaming system. P2P streaming system is vulnerable to DDoS attacks due to its high bandwidth demand and strict time requirement. In this paper, we propose a distributed framework to defense DDoS attack based on Credit Model(CM) which takes the responsibility to identify malicious nodes and categorize nodes into different credit level. We also introduce a Message Rate Controlling Model (MRCM)to control the message rate of a node according to its credit level. Combining CM and MRCS together, our framework can improve the resistibility against DDoS for P2P streaming system.
RFID-Based Interactive Learning in Science Museums
Authors: Yo-Ping Huang, Yueh-Tsun Chang, Frode Eika Sandnes
Venue: Proceedings of the 5th international conference on Ubiquitous Intelligence and Computing (2008)

Science and engineering education play a very important role in the industrial development of a country. Although most people are aware of the importance of science, students often find science boring and uninteresting as traditional textbooks only provide static information. Students who achieve better usually have practical experiences related to the subject or have been exposed to interactive learning tools. In order to promote science education development, a learning system based on RFID is proposed to provide personalized learning service. This paper introduces the architecture of the proposed service and the technologies used including RFID and collaborative filtering. The contributions of the proposed system and how the profiles are used to provide personalization are also discussed. Evaluations of the system reveal that the system inspires and nurtures their interest in science.
Towards a Better Blended Learning: Experiences of Adult Learners in Hong Kong
Authors: Po Wan Lee, F. T. Chan
Venue: Proceedings of the 1st international conference on Hybrid Learning and Education (2008)

The rapid development of information and communication technology brings along many impacts to education and training. Though delivery of courses solely based on e-learning on its own is not totally satisfactory to students and course providers, distance learning and face-to-face courses benefit from the use of e-learning as a support in the teaching and learning process. Surveys of Hong Kong part-time students clearly indicated that they preferred a blended learning mode that retains some form of face-to-face teaching and utilizes e-learning at the same time. However, effective blended learning is not simply using technology as an additional communication means or organizing extra learning activities. Web-based technology should be used as communication and collaborative tools. Pedagogy has to be adjusted to incorporate e-learning as an integral part of the teaching and learning process. Through the proper design of course, better integration of assessment, learning activities and use of technology for facilitating interactions via online community, meaningful blended learning experience can be resulted.
Books
Authors: R. Torsten Clay, Richard Gass
Venue: Computing in Science and Engineering (2008)

This installment of the Book Review department features two full reviews: one on an "Introduction to Computational Science: Modeling and Simulation for the Sciences" by A.B. Shiflet and G.W. Shiflet ("A System Dynamics Approach to Teaching Computational Science"), and the other on "Computer Algebra Recipes: An Advanced Guide to Scientific Modeling" by R. Torsten Clay ("Computational Recipes").
KAIFIA: Knowledge Assisted Intelligent Framework for Information Access
Authors: Atta Badii, Chattun Lallah, Oleksandr Kolomiyets, Meng Zhu, Michael Crouch
Venue: Scaling Topic Maps: Third International Conference on Topic Maps Research and Applications, TMRA 2007 Leipzig, Germany, October 11-12, 2007 Revised Selected Papers (2008)

Accessing information, which is spread across multiple sources, in a structured and connected way, is a general problem for enterprises. A unified structure for knowledge representation is urgently needed to enable integration of heterogeneous information resources. Topic Maps seem to be a solution for this problem. The Topic Map technology enables connecting information, through concepts and relationships, and their occurrences across multiple systems. In this paper, we address this problem by describing a framework built on topic maps, to support the current need of knowledge management. New approaches for information integration, intelligent search and topic map exploration are introduced within this framework.
Geometry optimization and computational electromagnetics: methods and applications
Authors: Daniel S. Weile
Venue:  (2007)

A new geometry optimization scheme, based on computational geometry methods, is developed and applied to electromagnetic problems. Geometry optimization is an important problem and has applications in inverse scattering and electromagnetic device design. The basic method uses a novel geometric representation that can represent any topology and is also amenable to stochastic optimization methods. Though only developed here for two-dimensional problems, the method can be extended to three dimensions without altering any of its useful properties. As motivation, a phononic bandgap design problem is first developed and attempted using a pixel filling approach. Though decent results are achieved, the possible solutions are inherently limited by the geometric representation. The new method is then introduced and applied to the inverse scattering of conducting cylinders. Subsequently, homogeneous and inhomogeneous dielectric inverse scattering problems are solved and the efficiency of the method is addressed using local search methods. Finally, several advances in electromagnetic solvers, specifically time domain Nystr&ouml;m methods, are reported. These methods offer advantages over other competing methods and could be used with different geometry design problems.
Hybrid intelligent path planning for articulated rovers in rough terrain
Authors: Mahmoud Tarokh
Venue: Fuzzy Sets and Systems (2008)

The paper develops a hybrid intelligent approach to path planning for high mobility robots operating in rough environments. Path planning consists of characterization of the environment using a fuzzy logic framework, and a two-stage genetic algorithm planner. A global planner determines the path that optimizes a combination of terrain roughness and path curvature. A local planner uses sensory information, and in case of detection of previously unknown and unaccounted for obstacles, performs an on-line replanning to get around the newly discovered obstacle. Fuzzy adaptation of the genetic operators is achieved by adjusting the probabilities of the operators based on a diversity measure of the paths population and traversability measure of the paths. Path planning for an articulated rover in a rugged Mars terrain is presented to demonstrate the effectiveness of the proposed path planner.
An Audio-Haptic Aesthetic Framework Influenced by Visual Theory
Authors: Angela Chang, Conor O'Sullivan
Venue: Proceedings of the 3rd international workshop on Haptic and Audio Interaction Design (2008)

Sound is touch at a distance. The vibration of pressure waves in the air creates sounds that our ears hear, at close range, these pressure waves may also be felt as vibration. This audio-haptic relationship has potential for enriching interaction in human-computer interfaces. How can interface designers manipulate attention using audio-haptic media? We propose a theoretical perceptual framework for design of audio-haptic media, influenced by aesthetic frameworks in visual theory and audio design. The aesthetic issues of the multimodal interplay between audio and haptic modalities are presented, with discussion based on anecdotes from multimedia artists. We use the aesthetic theory to develop four design mechanisms for transition between audio and haptic channels:synchronization, temporal linearization, masking andsynchresis. An example composition using these mechanisms, and the multisensory design intent, is discussed by the designers.
Adaptive iterative thresholding algorithms for magnetoencephalography (MEG)
Authors: Massimo Fornasier, Francesca Pitolli
Venue: Journal of Computational and Applied Mathematics (2008)

We provide fast and accurate adaptive algorithms for the spatial resolution of current densities in MEG. We assume that vector components of the current densities possess a sparse expansion with respect to preassigned wavelets. Additionally, different components may also exhibit common sparsity patterns. We model MEG as an inverse problem with joint sparsity constraints, promoting the coupling of non-vanishing components. We show how to compute solutions of the MEG linear inverse problem by iterative thresholded Landweber schemes. The resulting adaptive scheme is fast, robust, and significantly outperforms the classical Tikhonov regularization in resolving sparse current densities. Numerical examples are included.
Towards the quality of service for voip traffic in ieee 802.11 wireless networks
Authors: Sangho Shin
Venue:  (2008)

The usage of voice over IP (VoIP) traffic in IEEE 802.11 wireless networks is expected to increase in the near future due to widely deployed 802.11 wireless networks and VoIP services on fixed lines. However, the quality of service (QoS) of VoIP traffic in wireless networks is still unsatisfactory. In this thesis, I identify several sources for the QoS problems of VoIP traffic in IEEE 802.11 wireless networks and propose solutions for these problems. The QoS problems discussed can be divided into three categories, namely, user mobility, VoIP capacity, and call admission control. User mobility causes network disruptions during handoffs. In order to reduce the handoff time between Access Points (APs), I propose a new handoff algorithm, Selective Scanning and Caching, which finds available APs by scanning a minimum number of channels and furthermore allows clients to perform handoffs without scanning, by caching AP information. I also describe a new architecture for the client and server side for seamless IP layer handoffs, which are caused when mobile clients change the subnet due to layer 2 handoffs. I also present two methods to improve VoIP capacity for 802.11 networks, Adaptive Priority Control (APC) and Dynamic Point Coordination Function (DPCF). APC is a new packet scheduling algorithm at the AP and improves the capacity by balancing the uplink and downlink delay of VoIP traffic, and DPCF uses a polling based protocol and minimizes the bandwidth wasted from unnecessary polling, using a dynamic polling list. Additionally, I estimated the capacity for VoIP traffic in IEEE 802.11 wireless networks via theoretical analysis, simulations, and experiments in a wireless test-bed and show how to avoid mistakes in the measurements and comparisons. Finally, to protect the QoS for existing VoIP calls while maximizing the channel utilization, I propose a novel admission control algorithm called QP-CAT (Queue size Prediction using Computation of Additional Transmission), which accurately predicts the impact of new voice calls by virtually transmitting virtual new VoIP traffic.
On optimal condition numbers for Markov chains
Authors: Stephen J. Kirkland, Michael Neumann, Nung-Sing Sze
Venue: Numerische Mathematik (2008)

Let T and $${\tilde{T}=T-E}$$be arbitrary nonnegative, irreducible, stochastic matrices corresponding to two ergodic Markov chains on n states. A function &#x03ba; is called a condition number for Markov chains with respect to the (&#x03b1;, &#x03b2;)&#x2013;norm pair if $${\|\pi-\tilde{\pi}\|_\alpha \leq \kappa(T)\|E\|_\beta}$$. Here &#x03c0; and $${\tilde \pi}$$are the stationary distribution vectors of the two chains, respectively. Various condition numbers, particularly with respect to the (1, &#x221e;) and (&#x221e;, &#x221e;)-norm pairs have been suggested in the literature. They were ranked according to their size by Cho and Meyer in a paper from 2001. In this paper we first of all show that what we call the generalized ergodicity coefficient $${\tau_p(A^\#)={\rm sup}_{y^{t}e=0} \frac{\|y^tA^\#\|_p}{\|y\|_1}}$$, where e is the n-vector of all 1&#x2019;s and A # is the group generalized inverse of A&#x00a0;=&#x00a0;I&#x00a0;&#x2212;&#x00a0;T, is the smallest condition number of Markov chains with respect to the (p, &#x221e;)-norm pair. We use this result to identify the smallest condition number of Markov chains among the (&#x221e;, &#x221e;) and (1, &#x221e;)-norm pairs. These are, respectively, &#x03ba; 3 and &#x03ba; 6 in the Cho&#x2013;Meyer list of 8 condition numbers. Kirkland has studied &#x03ba; 3(T). He has shown that $${\kappa_3(T)\geq\frac{n-1}{2n}}$$and he has characterized transition matrices for which equality holds. We prove here again that 2&#x03ba; 3(T)&#x00a0;&#x2264; &#x03ba;(6) which appears in the Cho&#x2013;Meyer paper and we characterize the transition matrices T for which $${\kappa_6(T)=\frac{n-1}{n}}$$. There is actually only one such matrix: T&#x00a0;=&#x00a0;(J n &#x00a0;&#x2212;&#x00a0;I)/(n&#x00a0;&#x2212;&#x00a0;1), where J n is the n&#x00a0;&#x00d7; n matrix of all 1&#x2019;s.
Assessment of the Accuracy of the Process of Ceramics Grinding with the Use of Fuzzy Interference
Authors: Dariusz Lipiński, Wojciech Kacalak
Venue: Proceedings of the 8th international conference on Adaptive and Natural Computing Algorithms, Part I (2007)

Grinding of ceramic materials is an expensive process considering the cost of abrasive tools and a relatively small machining efficiency. This paper presents methods to increase the use of the technological potential of automatic machining of ceramic materials with a concurrent control of the machining accuracy. A method of an assessment of the influence of process variables monitored on the accuracy of the sizes and shape of ceramic elements machined was presented. An application of fuzzy interference methods facilitated a creation of a universal algorithm to assess the accuracy of machining independent of the accepted parameters and machining conditions.
Towards a Semi-automatic Situation Diagnosis System in Surveillance Tasks
Authors: José Mira, Rafael Martínez, Mariano Rincón, Margarita Bachiller, Antonio Fernández-Caballero
Venue: Proceedings of the 2nd international work-conference on Nature Inspired Problem-Solving Methods in Knowledge Engineering: Interplay Between Natural and Artificial Computation, Part II (2007)

This paper describes an ongoing project that develops a set of generic components to help humans (semi-automatic system) in surveillance and security tasks in several scenarios. These components are based in the computational model of a set of selective and Active VISual Attention mechanisms with learning capacity (AVISA) and in the superposition of an "intelligence" layer that incorporates the knowledge of human experts in security tasks. The project described integrates the responses of these alert mechanisms in the synthesis of the three basic subtasks present in any surveillance and security activity: real-time monitoring, situation diagnosing, and action planning and control. In order to augment the diversity of environments and situations where AVISA system may be used, as well as its efficiency as support to surveillance tasks, knowledge components derived from situating cameras on mobile platforms are also developed.
Note: Efficient edge domination in regular graphs
Authors: Domingos M. Cardoso, J. Orestes Cerdeira, Charles Delorme, Pedro C. Silva
Venue: Discrete Applied Mathematics (2008)

An induced matching of a graph G is a matching having no two edges joined by an edge. An efficient edge dominating set of G is an induced matching M such that every other edge of G is adjacent to some edge in M. We relate maximum induced matchings and efficient edge dominating sets, showing that efficient edge dominating sets are maximum induced matchings, and that maximum induced matchings on regular graphs with efficient edge dominating sets are efficient edge dominating sets. A necessary condition for the existence of efficient edge dominating sets in terms of spectra of graphs is established. We also prove that, for arbitrary fixed p>=3, deciding on the existence of efficient edge dominating sets on p-regular graphs is NP-complete.
A Framework for Distributing Real-Time Functions
Authors: Frédéric Boniol, Pierre-Emmanuel Hladik, Claire Pagetti, Frédéric Aspro, Victor Jégu
Venue: Proceedings of the 6th international conference on Formal Modeling and Analysis of Timed Systems (2008)

The design of critical embedded real-time systems requires high confidence in the architecture and the implemented functionalities. Classically, such functions are supported on a single monoprocessor, behavior of which is completely predictable, while the execution is totally deterministic. With the growing complexity of systems, it becomes quite unavoidable to implement these systems on distributed architectures. Scaling from mono to multiprocessor raises several issues which we address in this paper: we propose a simple executive model based on time triggered paradigm and an automated approach to allocate real-time tasks based on constraint resolution techniques. We illustrate the method on an industrial case study.
Performance prediction of large-scale parallell system and application using macro-level simulation
Authors: Ryutaro Susukita, Hisashige Ando, Mutsumi Aoyagi, Hiroaki Honda, Yuichi Inadomi, Koji Inoue, Shigeru Ishizuki, Yasunori Kimura, Hidemi Komatsu, Motoyoshi Kurokawa, Kazuaki J. Murakami, Hidetomo Shibamura, Shuji Yamamura, Yunqing Yu
Venue: Proceedings of the 2008 ACM/IEEE conference on Supercomputing (2008)

To predict application performance on an HPC system is an important technology for designing the computing system and developing applications. However, accurate prediction is a challenge, particularly, in the case of a future coming system with higher performance. In this paper, we present a new method for predicting application performance on HPC systems. This method combines modeling of sequential performance on a single processor and macro-level simulations of applications for parallel performance on the entire system. In the simulation, the execution flow is traced but kernel computations are omitted for reducing the execution time. Validation on a real terascale system showed that the predicted and measured performance agreed within 10% to 20 %. We employed the method in designing a hypothetical petascale system of 32768 SIMD-extended processor cores. For predicting application performance on the petascale system, the macro-level simulation required several hours.
Interest of Spatial Context for a Place Cell Based Navigation Model
Authors: Nicolas Cuperlier, Philippe Gaussier, Mathias Quoy
Venue: Proceedings of the 10th international conference on Simulation of Adaptive Behavior: From Animals to Animats (2008)

After a short review of properties of biological place cells, mainly found in the hippocampal region of rodents, and a brief presentation of a biologically inspired navigation architecture relying on these cells, we will show how contextual information could facilitate scale changes to large environments. We thus present a simple model of spatial context allowing to both reduce noise effects on place cells (in biological model) and increase its computational performance.
Voicing Detection in Noisy Speech Signal
Authors: Aïcha Bouzid, Noureddine Ellouze
Venue: Proceedings of the 3rd international conference on Image and Signal Processing (2008)

An algorithm for voicing detection in noisy speech signal is proposed. This algorithm is based on the product of wavelet transforms at some scales called multi-scale product. The multi-scale product has the ability to reinforce the edge in the signal while suppressing additive noise. Motivated by the fact that unvoiced sounds are, in most important speech production models, considered as filtered noise, we apply the multi-scale product on speech signal for detection of voiced segments. In fact, the multi-scale product anneals the signal frames corresponding to unvoiced sounds and frames of silence, while it conserves speech periodicity for voiced frames.
A Lyapunov shortest-path characterization for Markov decision processes
Authors: Julio Clempner, Jesus Medel
Venue: Proceedings of the American Conference on Applied Mathematics (2008)

In this paper we introduce a modeling paradigm for developing decision process representation for shortest-path problems. Whereas, in previous work attention was restricted to tracking the net using Bellman's equation as a utility function, this work uses a Lyapunov-like function. In this sense, we are changing the traditional cost function by a trajectory-tracking function which is also an optimal cost-to-target function for tracking the net. The main point of the Markov decision process is its ability to represent the system-dynamic and trajectory-dynamic properties of a decision process. Within the system-dynamic properties framework we prove new notions of equilibrium and stability. In the trajectory-dynamic properties framework, we optimize the value of the trajectory-function used for path planning via a Lyapunov-like function, obtaining as a result new characterizations for final decision points (optimum points) and stability. Moreover, we show that the system-dynamic and Lyapunov trajectory-dynamic properties of equilibrium, stability and final decision points (optimum points) meet under certain restrictions.