ppxscal/embedding_network huggingface dataset:
The age of gossip: spatial mean field regime
Authors: Augustin Chaintreau, Jean-Yves Le Boudec, Nikodin Ristanovic
Venue: Proceedings of the eleventh international joint conference on Measurement and modeling of computer systems (2009)

Disseminating a piece of information, or updates for a piece of information, has been shown to benefit greatly from simple randomized procedures, sometimes referred to as gossiping, or epidemic algorithms. Similarly, in a network where mobile nodes occasionally receive updated content from a base station, gossiping using opportunistic contacts allows for recent updates to be efficiently maintained, for a large number of nodes. In this case, however, gossiping depends on node mobility. For this reason, we introduce a new gossip model, with mobile nodes moving between different classes that can represent locations or states, which determine gossiping behavior of the nodes. Here we prove that, when the number of mobile nodes becomes large, the age of the latest updates received by mobile nodes approaches a deterministic mean-field regime. More precisely, we show that the occupancy measure of the process constructed, with the ages defined above, converges to a deterministic limit that can be entirely characterized by differential equations. This major simplification allows us to characterize how mobility, source inputs and gossiping influence the age distribution for low and high ages. It also leads to a scalable numerical evaluation of the performance of mobile update systems, which we validate (using a trace of 500 taxicabs) and use to propose infrastructure deployment.
Plenary lecture 8: towards opposition and center-based sampling for high-dimensional search spaces
Authors: Shahryar Rahnamayan
Venue: Proceedings of the 8th WSEAS international conference on Artificial intelligence, knowledge engineering and data bases (2009)

Footprints of the opposition concept can be observed in many areas around us. But it has sometimes been called by different names. Opposite particles in physics, complement of an event in probability, absolute or relative complement in set theory, and theses and antitheses in dialectic just are some examples to mention. Recently for the first time, Opposition-Based Learning (OBL) was proposed and then the opposition-based methods have been introduced in different artificial intelligence areas. All of them have tried to enhance searching or leaning process by utilizing the opposition concept. Opposition-based evolutionary algorithms, opposition-based neural networks, and also opposition-based reinforcement learning are some efforts in this direction. The main idea behind OBL is the simultaneous consideration of a candidate and its corresponding opposite candidate in order to achieve a better approximation for the current solution. The first and second parts of this lecture introduce the opposition-based sampling and its applications in various soft computing techniques and center-based sampling, respectively. Population-based algorithms, such as Differential Evolution (DE), Particle Swarm Optimization (PSO), Genetic Algorithms (GAs), and Evolutionary Strategies (ES) are commonly used approaches to solve complex problems from science and engineering. They work with a population of candidate solutions. In this lecture, a novel center-based sampling is introduced for these algorithms. Reducing the number of function evaluations to tackle with high-dimensional problems is a worthwhile attempt; the proposed center-based sampling can open a new research area in this direction. Our simulation results confirm that this kind of sampling, which can be utilized during population initialization and/or generating successive generations, can be valuable in solving high-dimensional problems efficiently. Quasi-Oppositional Differential Evolution (QODE) will briefly be discussed as an evidence to support the proposed sampling theory. Finally, the opposition-based sampling and center-based sampling will be compared in this lecture.
JUnitMX - A change-aware unit testing tool
Authors: Jan Wloka, Barbara G. Ryder, Frank Tip
Venue: Proceedings of the 2009 IEEE 31st International Conference on Software Engineering (2009)

Developers use unit testing to improve the quality of software systems. Current development tools for unit testing help with automating test execution, with reporting results, and with generating test stubs. However, they offer no aid for designing tests aimed specifically at exercising the effects of changes to a program. This paper describes a unit testing tool that leverages a change model to assist developers in the creation of new unit tests. The tool provides developers with quantitative feedback and detailed information about change effects, which not only facilitate the writing of more effective tests, but also motivate developers with an achievable coverage goal.
Unrestored Flow Optimization in Survivable Networks Based on p-Cycles
Authors: Adam Smutnicki
Venue: Proceedings of the 9th International Conference on Computational Science: Part I (2009)

This paper deals with Unrestorable Flow Optimisation (UFO) problem in networks protected by p-cycles. This novel protection technique is used as the efficient tool for ensuring survivability of computer networks. In this paper there have been formulated mathematical model of UFO problem, discussed its theoretical properties, and proposed the original solution algorithm based chiefly on metaheuristics. The algorithm combines k-shortest paths method, multi knapsack problem, p-cycles generator, linear programming and some local search procedures.
Tight bounds from a path based formulation for the tree of hub location problem
Authors: Ivan Contreras, Elena Fernández, Alfredo Marín
Venue: Computers and Operations Research (2009)

This paper considers the tree of hub location problem. We propose a four index formulation which yields much tighter LP bounds than previously proposed formulations, although at a considerable increase of the computational burden when obtained with a commercial solver. For this reason we propose a Lagrangean relaxation, based on the four index formulation, that exploits the structure of the problem by decomposing it into independent subproblems which can be solved quite efficiently. We also obtain upper bounds by means of a simple heuristic that is applied at the inner iterations of the method that solves the Lagrangean dual. As a consequence, the proposed Lagrangean relaxation produces tight upper and lower bounds and enable us to address instances up to 100 nodes, which are notably larger than the ones previously considered in the literature, with sizes up to 20 nodes. Computational experiments have been performed with benchmark instances from the literature. The obtained results are remarkable. For most of the tested instances we obtain or improve the best known solution and for all tested instances the deviation between our upper and lower bounds, never exceeds 10%.
Network Design with Weighted Players
Authors: Ho-Lin Chen, Tim Roughgarden
Venue: Theory of Computing Systems (2009)

We consider a model of game-theoretic network design initially studied by Anshelevich et&#x00a0;al. (Proceedings of the 45th Annual Symposium on Foundations of Computer Science (FOCS), pp. 295&#x2013;304, 2004), where selfish players select paths in a network to minimize their cost, which is prescribed by Shapley cost shares. If all players are identical, the cost share incurred by a player for an edge in its path is the fixed cost of the edge divided by the number of players using it. In this special case, Anshelevich et&#x00a0;al. (Proceedings of the 45th Annual Symposium on Foundations of Computer Science (FOCS), pp. 295&#x2013;304, 2004) proved that pure-strategy Nash equilibria always exist and that the price of stability&#x2014;the ratio between the cost of the best Nash equilibrium and that of an optimal solution&#x2014;is &#x0398;(log&#x2009;k), where k is the number of players. Little was known about the existence of equilibria or the price of stability in the general weighted version of the game. Here, each player i has a weight w i &#x2265;1, and its cost share of an edge in its path equals w i times the edge cost, divided by the total weight of the players using the edge. This paper presents the first general results on weighted Shapley network design games. First, we give a simple example with no pure-strategy Nash equilibrium. This motivates considering the price of stability with respect to &#x03b1;-approximate Nash equilibria&#x2014;outcomes from which no player can decrease its cost by more than an &#x03b1; multiplicative factor. Our first positive result is that O(log&#x2009;w max&#x2009;)-approximate Nash equilibria exist in all weighted Shapley network design games, where w max&#x2009; is the maximum player weight. More generally, we establish the following trade-off between the two objectives of good stability and low cost: for every &#x03b1;=&#x03a9;(log&#x2009;w max&#x2009;), the price of stability with respect to O(&#x03b1;)-approximate Nash equilibria is O((log&#x2009;W)/&#x03b1;), where W is the sum of the players&#x2019; weights. In particular, there is always an O(log&#x2009;W)-approximate Nash equilibrium with cost within a constant factor of optimal. Finally, we show that this trade-off curve is nearly optimal: we construct a family of networks without o(log&#x2009;w max&#x2009;/ log&#x2009;log&#x2009;w max&#x2009;)-approximate Nash equilibria, and show that for all &#x03b1;=&#x03a9;(log&#x2009;w max&#x2009;/log&#x2009;log&#x2009;w max&#x2009;), achieving a price of stability of O(log&#x2009;W/&#x03b1;) requires relaxing equilibrium constraints by an &#x03a9;(&#x03b1;) factor.
A Variational Model for Interactive Shape Prior Segmentation and Real-Time Tracking
Authors: Manuel Werlberger, Thomas Pock, Markus Unger, Horst Bischof
Venue: Proceedings of the Second International Conference on Scale Space and Variational Methods in Computer Vision (2009)

In this paper, we introduce a semi-automated segmentation method based on minimizing the Geodesic Active Contour energy incorporating a shape prior. We increase the robustness of the segmentation result using the additional shape information that represents the desired structure. Furthermore the user has the possibility to take corrective actions during the segmentation and adapt the shape prior position. Interaction is often desirable when processing difficult data like in medical applications. To facilitate the user interaction we add a shape deformation which allows to change the shape position manually by the user and automatically in terms of underlying image features. Using a variational formulation, the optimization can be done in a globally optimal manner for a fixed shape representation. To obtain real-time behavior, which is especially important for an interactive tool, the whole method is implemented on the GPU. Experiments are done on medical, as well as on video data and camera streams that are processed in real-time. In terms of medical data we compare our method with a segmentation done by an expert. The GPU based binaries will be available online on our homepage.
Six-DoF haptic rendering of contact between geometrically complex reduced deformable models: Haptic demo
Authors: Jernej Barbic, Doug L. James
Venue: Proceedings of the World Haptics 2009 - Third Joint EuroHaptics conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (2009)

In this demonstration, we show haptic results from our research on distributed contact between deformable objects with complex geometry [1, 2, 3]. The demos run at 1000 Hz, and support 6-DoF haptic rendering. Real-time evaluation of distributed contact forces between rigid or deformable 3D objects is a key ingredient of 6-DoF force-feedback rendering. We demonstrate a spatially and temporally adaptive approach to approximate distributed contact forces under hard real-time constraints. Our method is CPU based, and supports contact between rigid or reduced deformable models with complex geometry. We propose a contact model that uses a point-based representation for one object, and a signed-distance field for the other. This model is related to the Voxmap Pointshell Method (VPS), but gives continuous contact forces and torques, enabling stable rendering of stiff penalty-based distributed contacts.
Speeding up HMM algorithms for genetic linkage analysis via chain reductions of the state space
Authors: Dan Geiger, Christopher Meek, Ydo Wexler
Venue: Bioinformatics (2009)

We develop an hidden Markov model (HMM)-based algorithm for computing exact parametric and non-parametric linkage scores in larger pedigrees than was possible before. The algorithm is applicable whenever there are chains of persons in the pedigree with no genetic measurements and with unknown affection status. The algorithm is based on shrinking the state space of the HMM considerably using such chains. In a two g-degree cousins pedigree the reduction drops the state space from being exponential in g to being linear in g. For a Finnish family in which two affected children suffer from a rare cold-inducing sweating syndrome, we were able to reduce the state space by more than five orders of magnitude from 250 to 232. In another pedigree of state-space size of 227, used for a study of pituitary adenoma, the state space reduced by a factor of 8.5 and consequently exact linkage scores can now be computed, rather than approximated. Contact: dang@cs.technion.ac.il Supplementary information: Supplementary data are available at Bioinformatics online.
Automated Scoring for Creative Problem Solving Ability with Ideation-Explanation Modeling
Authors: Hao-Chuan Wang, Chun-Yen Chang, Tsai-Yen Li
Venue: Proceeding of the 2005 conference on Towards Sustainable and Scalable Educational Innovations Informed by the Learning Sciences: Sharing Good Practices of Research, Experimentation and Innovation (2005)

This paper describes an automated scorer for assessing students' Creative Problem-Solving (CPS) abilities via modeling the intra-structure of students' essays describing their thoughts on solving particular problems. The automated scorer aims to grade students' open-ended responses to an essay-question-type CPS ability test, instead of using typical Likert-type or multiple-choice questions that may be imperfect to assess the creative perspective of human problem-solving. The scorer is distinguishable to most generic automated essay scoring systems that a bipartite graph-based representation is explicitly built for the pair-wise relation between a student's ideas and self-explained reasons for a CPS task. This design will enable several analytical approaches for CPS, such as quantitative scoring and qualitative diagnoses. The preliminary empirical evaluation with 20 students' data shows that the scoring results of the scorer is satisfactory and highly correlated with those of human experts (Pearson's r=.67∼.82) in terms of quantitative scoring task. The approach provides a promising solution to support large-scaled studies on human creativity and may further enable CPS-aware personalization systems.
Advanced Digital Black & White Photography
Authors: John Beardsworth
Venue:  (2007)

Digital photographers can now attain the enduring beauty of black-and-white photography in their own work! Theres more to monochrome than just discarding the color in Photoshop, but many books simply treat it as an afterthought. Not this one! John Beardsworth teaches every major method of making a color picture black and white, and explains what kind of images are best, and why. Both ambitious newcomers and advanced enthusiasts will learn how to achieve the richest tonal depth and balance, use black and white to interpret the subject for the viewer, reproduce historic and darkroom processes, add creative and special effects, and produce exhibition-quality prints. The ACM Portal is published by the Association for Computing Machinery. Copyright © 2010 ACM, Inc. Terms of Usage Privacy Policy Code of Ethics Contact Us Useful downloads: Adobe Acrobat QuickTime Windows Media Player Real Player
A Fast VQ Codebook Generation Algorithm Based on Otsu Histogram Threshold
Authors: Chang-Chin Huang, Du-Shiau Tsai, Gwoboa Horng
Venue: Fundamenta Informaticae (2009)

In vector quantization, the codebook generation problem can be formulated as a classification problem of dividing N$_{p}$ training vectors into N$_{c}$ clusters, where N$_{p}$ is the training size of input vectors and N$_{c}$ is the codeword size of codebook. For large N$_{p}$ and N$_{c}$, a traditional search algorithmsuch as the LBG method can hardly find the global optimal classification and needs a great deal of calculation. In this paper, a novel VQ codebook generation method based on Otsu histogram threshold is proposed. The computational complexity of squared Euclidean distance can be reduced to O(N$_{p}$ log$_{2}$ N$_{c}$) for a codebook with gray levels. Our method provides better image quality than recent proposed schemes in high compression ratio. The experimental results and the comparisons show that this method can not only reduce the computational complexity of squared Euclidean distance but also find better codewords to improve the quality of the resulted VQ codebook.
Adaptive Tabu Search and Applications in Engineering Design
Authors: Sarawut Sujitjorn, Thanatchai Kulworawanichpong, Deacha Puangdownreong, Kongpan Areerak
Venue: Proceeding of the 2006 conference on Integrated Intelligent Systems for Engineering Design (2006)

This chapter presents detailed step-by-step description of an intelligent search algorithm namely Adaptive Tabu Search (ATS). The proof of its convergence, and its performance evaluation are illustrated. The chapter demonstrates the effectiveness and usefulness of the ATS through various engineering applications and designs in the following fields: power system, identification, and control.
Agilla: A mobile agent middleware for self-adaptive wireless sensor networks
Authors: Chien-Liang Fok, Gruia-Catalin Roman, Chenyang Lu
Venue: ACM Transactions on Autonomous and Adaptive Systems (TAAS) (2009)

This article presents Agilla, a mobile agent middleware designed to support self-adaptive applications in wireless sensor networks. Agilla provides a programming model in which applications consist of evolving communities of agents that share a wireless sensor network. Coordination among the agents and access to physical resources are supported by a tuple space abstraction. Agents can dynamically enter and exit a network and can autonomously clone and migrate themselves in response to environmental changes. Agilla's ability to support self-adaptive applications in wireless sensor networks has been demonstrated in the context of several applications, including fire detection and tracking, monitoring cargo containers, and robot navigation. Agilla, the first mobile agent system to operate in resource-constrained wireless sensor platforms, was implemented on top of TinyOS. Agilla's feasibility and efficiency was demonstrated by experimental evaluation on two physical testbeds consisting of Mica2 and TelosB nodes.
A novel network mobility handoff scheme using SIP and SCTP for multimedia applications
Authors: Fang-Yie Leu
Venue: Journal of Network and Computer Applications (2009)

In a heterogeneous wireless environment, seamless mobility is the basis of network support with which mobile users who roam between or among various wireless access networks are able to fully enjoy uninterrupted wireless services. When users are in a mass transportation vehicle, e.g., a bus or a train that provides network service, the vehicle can be regarded as a network which is serving users as it moves from one location to another. The movement of a network is called network mobility (NEMO). The network mobility protocol based on Mobile IPv6 as proposed by the Internet Engineering Task Force (IETF) in 2005 has some fundamental drawbacks, such as header overhead and the pinball problem. In this paper, we propose a novel hybrid method for network mobility called Hybrid-NEMO, which provides a soft handoff scheme at the transport layer basically utilizing SIP and SCTP protocols to ensure a lossless packet-transmission environment and less handoff-delay variation, which are critical in providing QoS voice and multimedia applications. Experimental validation and performance evaluation were also conducted in this study.
Teaching Cryptography Activity in Taiwan's High Schools
Authors: Long-Yuan Yan
Venue: Proceeding of the 2007 conference on Supporting Learning Flow through Integrative Technologies (2007)

This article tries to experiment with a cryptography activity in Taiwan's high schools. In this activity it is unnecessary to use the computer; instead, the hand-on activity is used to teach the concepts of cryptography. We teach the “Can I do the cryptography as well?” and “Funny Code --The Dancing Men” in normal classrooms with activity-based course, and these concepts originally can only be taught in the university. The results of experiment show some positive facts. Before the learning activities, 60% students thought that cryptography was very difficult and 56% students thought that cryptography was not easy to understand. However, after the learning activities, 41% students like this new method; 44% students think that cryptography is simple; 24% students think that cryptography is easy to understand. These data show this pedagogy deserves further analysis and to be put into practice on a large scale.
An auction-based dynamic bandwidth allocation with sensitivity in a wireless networked control system
Authors: Yodyium Tipsuwan, Suwatchai Kamonsantiroj, Jirat Srisabye, Prabhas Chongstitvattana
Venue: Computers and Industrial Engineering (2009)

Applications of control systems on wireless networks have been widely utilized due to their mobility. However, the performances of these networked control systems (NCS) could be degraded and become unstable by network-induced delays. Existing dynamic bandwidth allocation methods for NCS assign bandwidth to each system with respect to different priorities in an ascending order. However, these NCS may not be given bandwidths at equilibrium such that each of these NCS is satisfied with respect to bandwidth requests of other NCS. Therefore, some NCS may always consume most of given bandwidths, while others may never be given satisfied bandwidths. This paper proposes a dynamic bandwidth allocation methodology that controls bandwidths given to open-loop NCS to be at Nash equilibrium. In this paper, the average sensitivities of NCS are used in utility functions in order to evaluate the effects of network-induced delays for NCS. Then, a control center or an access point will use the proposed methodology to allocate bandwidths for all NCS based on Nash equilibrium. Simulations and experiments were setup from a set of DC motors controlled over a wireless network. Simulation and experimental results show good performances of the proposed methodology compared with three other methods.
OntoMusic: from Scores to Expressive Music Performances
Authors: Pere Ferrera, Josep Puyol-Gruart
Venue: Proceeding of the 2005 conference on Artificial Intelligence Research and Development (2005)

The literal performance of the symbols contained in a traditional score is not enough to produce expressive music. Human interpreters use musical knowledge that is not explicitly represented in it. This paper presents a knowledge-based approach to introduce expressiveness to the performance of a score by calculating dynamics and tempo envelopes of the piece, combining implicit musical knowledge with the explicit one contained in the score.