ppxscal/embedding_network huggingface dataset:
Proceedings of the 8th ACM conference on Electronic commerce
Venue: Electronic Commerce (2007)

These proceedings present the technical contributions to the 8th ACM Conference on Electronic Commerce EC'07, held June 11-15, 2007, at the Federated Computer Research Conference in San Diego, California, USA. Since its inception in 1999, ACM EC has served as the leading scientific conference on advances in theory, systems, and applications for electronic commerce. The natural focus of the conference is on computer science issues, but the conference is interdisciplinary and addresses many facets of electronic commerce including (1) theory and foundations; (2) languages; (3) automation, personalization, and targeting; (4) security, privacy, encryption, and digital rights; (5) applications and empirical studies; and (6) social factors. In addition to the main technical program, EC'07 featured three workshops and four tutorials. The call for papers attracted 154 submissions from academia and industry around the world, including Africa, Asia, Canada, Europe, the Middle East, and the United States. Each paper was reviewed by at least three program committee members on the basis of scientific novelty, technical quality, and importance to the field. The program committee selected 42 papers for presentation at the conference, of which 40 are published in the proceedings. At the authors' request, only abstracts for the remaining papers are included along with pointers to full versions of these "working papers". This accommodates the practices of fields outside of computer science in which journal rather than conference publishing is the norm and conference publishing sometimes precludes journal publishing. Several papers were invited to a special issue of Games and Economic Behavior. Moshe Tennenholtz (Technion University) will join David Parkes as a guest editor of this special issue and invited papers will be subject to a thorough round of additional review. In addition, a couple of papers will be invited for fast-track journal publication in the ACM Transactions on the Web (TWEB).
The value of shared visual information for task-oriented collaboration
Authors: Robert E. Kraut
Venue:  (2006)

For several decades, researchers and engineers have struggled with the development of systems to support distance collaboration. The failure of many collaborative technologies is due, in part, to a limited understanding of how groups coordinate in collocated environments and how the coordination mechanisms of face-to-face collaboration are impacted by technology. The major goal of this thesis is to address this deficiency by building a theoretical understanding of the role that shared visual information plays in supporting group communication and performance during task-oriented collaboration. This understanding is developed over three major stages: (1) the development of a paradigm and a series of empirical studies that decompose the features of shared visual information and task structure and explore their interactions in detail, (2) the development and application of a methodology for describing the sequential structure of how visible actions support the understanding of discourse, and (3) the development of a computational model of discourse to further our theoretical understanding of the ways in which shared visual information serves communication in task-oriented collaborative discourse.
Information assurance vulnerability assessment for identifying data quality based risks
Authors: Edward J. Wegman
Venue:  (2007)

As the Department of Defense (DoD) moves to create decision superiority through the use of network centric operations, decision-makers become increasingly exposed to data quality vulnerabilities that mimic integrity failures within the Information Assurance (IA) security program. This outcome is a result of the current IA enforcement mechanism known as Defense Information Assurance Certification and Accreditation Process (DIACAP) not begin designed to mitigate risks involving data quality (accuracy, relevance, timeliness, usability, completeness, brevity, and security) beyond those associated with security. Misconceptions and the uncertainty created by the inability of decision-makers to distinguish between poor quality data and breaches of IA integrity lead to a reduced trust of critical DoD information systems. This research presents a modified Action Research process to expand IA risk evaluation criteria beyond the current security paradigm with the purpose of identifying undocumented data quality based risks.
Incentive-Compatible, Energy-Optimal, and Efficient Ad Hoc Networking in a Selfish Milieu
Authors: Stephan Eidenbenz, Luzi Anderegg, Roger Wattenhofer
Venue: Proceedings of the 40th Annual Hawaii International Conference on System Sciences (2007)

We propose SARP, a provably incentive-compatible and energy-efficient routing protocol for ad hoc networks. The key distinguishing factor when compared to previous proposals is the practicality and (relative) scalability of SARP due to a small communication complexity (analytically and practically), which is achieved by computing routing paths in a novel manner that borrows techniques from geometric routing. We also propose a solution on how to deliver payments (rather than only computing them). We support our claim that SARP works in realistic settings through comparative simulation results obtained from an implementation of SARP in GloMoSim.
A perceptual approach to trimming unstructured lumigraphs
Authors: Yann Morvan, Carol O'Sullivan
Venue: Proceedings of the 4th symposium on Applied perception in graphics and visualization (2007)

We present a novel perceptual method to reduce the visual redundancy of unstructured lumigraphs, an image based representation designed for interactive rendering. We combine features of the unstructured lumigraph algorithm and image fidelity metrics to efficiently rank the perceptual impact of the removal of sub-regions of input views (sub-views). We use a greedy approach to estimate the order in which sub-views should be pruned to minimize perceptual degradation at each step. Renderings using varying numbers of sub-views can then be easily visualized with confidence that the retained sub-views are well chosen, thus facilitating the choice of how many to retain. The regions of the input views that are left are repacked into a texture atlas. Our method takes advantage of any scene geometry information available but only requires a very coarse approximation. We perform a user study to validate its behaviour, as well as investigate the impact of the choice of image fidelity metric. The three metrics considered fall in the physical, statistical and perceptual categories. The overall benefit of our method is the semi-automation of the view selection process, resulting in unstructured lumigraphs that are thriftier in texture memory use and faster to render. (Note to reviewers: a video is available at http://isg.cs.tcd.ie/ymorvan/paper37.avi. The figure occupying the ninth page is intended to appear on a color plate.)
The effect of blanking of TDMA interference on radio-astronomical observations: experimental results
Authors: A. J. Boonstra
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 2000. on IEEE International Conference - Volume 06 (2000)

The fast growth of the wireless communication industry poses severe limitations on radio-astronomical observations. This is largely due to the fact that in radio astronomy, in contrast to communication systems, the signals of interest are many orders of magnitude below the receiver noise power levels. The structure of some communication signals opens the possibility to reduce the effect on radio-astronomical observations using advanced array processing techniques. One such structure is time slots, used in TDMA communication systems such as the Iridium system and the GSM system. We present the results of blanking of time-slotted interfering signals measured at the Westerbork Synthesis Radio Telescope.
Dynamic Video Resolution Control Based on Haptic Media in Haptic and Visual Communications
Authors: Seiji Kameyama, Yutaka Ishibashi
Venue: Proceedings of the Second Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (2007)

This paper proposes dynamic video resolution control based on haptic media in haptic and visual communications, where we can touch a real object located at a remote place by using haptic interface devices while watching the video of the object. Under the control, if the surface of the object being touched by a user is smooth, the temporal resolution of video is decreased; otherwise, we increase the resolution. We judge whether the surface of the object is smooth or not by using the positional information of haptic media. By experiment, we demonstrate the effectiveness of the control.
Computing all efficient solutions of the biobjective minimum spanning tree problem
Authors: Sarah Steiner, Tomasz Radzik
Venue: Computers and Operations Research (2008)

A common way of computing all efficient (Pareto optimal) solutions for a biobjective combinatorial optimisation problem is to compute first the extreme efficient solutions and then the remaining, non-extreme solutions. The second phase, the computation of non-extreme solutions, can be based on a ''k-best'' algorithm for the single-objective version of the problem or on the branch-and-bound method. A k-best algorithm computes the k-best solutions in order of their objective values. We compare the performance of these two approaches applied to the biobjective minimum spanning tree problem. Our extensive computational experiments indicate the overwhelming superiority of the k-best approach. We propose heuristic enhancements to this approach which further improve its performance.
A fast motion estimation algorithm based on multi-resolution frame structure
Authors: R. Chellappa
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1999. on 1999 IEEE International Conference - Volume 06 (1999)

We present a novel multi-resolution block matching algorithm (BMA) for fast motion estimation. At the coarsest level, a full search BMA (FSBMA) is performed for searching complex or random motion. Concurrently, spatial correlation of motion vector (MV) field is used for searching continuous motion. Here we present an efficient method for searching full resolution MVs without MV decimation even at the coarsest level. After the coarsest level search, two or three initial MV candidates are chosen for the next level. At the further levels, the MV candidates are refined within much smaller search areas. Simulation results show that in comparison with FSBMA, the proposed BMA achieves a speed-up factor over 710 with minor PSNR degradation of 0.2 dB at most, under a normal MPEG-2 coding environment. Furthermore, our scheme is also suitable for hardware implementation due to regular data-flow. 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
Multi-modal nonmonotonic logics of minimal knowledge
Authors: Riccardo Rosati
Venue: Annals of Mathematics and Artificial Intelligence (2006)

In this paper we introduce multi-modal logics of minimal knowledge. Such a family of logics constitutes the first proposal in the field of epistemic nonmonotonic logic in which the three following aspects are simultaneously addressed: (1) the possibility of formalizing multiple agents through multiple modal operators; (2) the possibility of using first-order quantification in the modal language; (3) the possibility of formalizing nonmonotonic reasoning abilities for the agents modeled, based on the principle of minimal knowledge. We illustrate the expressive capabilities of multi-modal logics of minimal knowledge to provide a formal semantics to peer-to-peer data integration systems, which constitute one of the most recent and complex architectures for distributed information systems.
Bayesian video object tracking
Authors: Jun Zhang
Venue:  (2006)

This is a study of tracking moving objects robustly and efficiently from a video stream. Video object tracking aids higher level image analysis by providing richer image information more efficiently. It can find many applications in smart video surveillance, video conferencing, human computer interface, traffic measurement, image stabilization, video compression, etc. However, it is still an open problem due to the difficulties from over/under segmentations, the different views of a moving object, the morphology of nonrigid objects, the occlusions of multiple moving objects, lighting changes, shadows, reflections, etc. These difficulties often result in frequent object loss, high false alarm ratio, and other problems. In this thesis we describe a Bayesian framework, combining with a novel model and an efficient particle filtering implementation, to combat those difficulties. The Bayesian approach is optimal in that it gives the minimum square error (MSE) estimation of the object's states being tracked. Because the key issue of this approach is modelling, a unique model was proposed and studied in this research. It consists of a compact representation of a moving object, a unique state vector formed from robust shape and colour features in addition to the often-used kinetic features, observations from motion detection, and their relationships described by the state dynamic and observation equations. This model has the advantages of being able to track non-rigid or shape-changing objects and being robust with lighting variations. In order to track multiple objects simultaneously, we studied the typical multiple hypothesis tracking algorithms and proposed a variation of the joint probability data association (JPDA) algorithm to solve the data association problem in video object tracking. For fully automatic tracking, a new technique based on sequential likelihood test is combined into the system for the object initialisation and deletion. This technique can greatly reduce the false-alarm ratio and track-loss frequency. The robustness and efficacy of the system are demonstrated by tracking various objects in a variety of applications, such as video based parking-plot surveillance, and video tracking from Unmanned Aerial Vehicles (UAVs).
A Laplacian spectral method for stereo correspondence
Authors: Jun Tang, Dong Liang, Nian Wang, Yi zheng Fan
Venue: Pattern Recognition Letters (2007)

This paper presents a novel algorithm of stereo correspondence by using Laplacian spectra of graphs. Firstly, according to the feature points of two images to be matched, a Laplacian matrix with Gaussian-weighted distance is defined and a closed-form solution is given in terms of the matching matrix constructed on the vectors of eigenspace of the Laplacian matrix. Secondly, we introduce a new method to judge correspondences by using doubly stochastic matrix. Thirdly, in order to render our method robust, we describe an approach to embedding the Laplacian spectral method within the framework of iterative correspondence and transformation estimation. Experimental results show the feasibility and comparatively high accuracy of our methods.
Braille Display by Lateral Skin Deformation with the STReSS2 Tactile Transducer
Authors: Vincent Levesque, Jerome Pasquero, Vincent Hayward
Venue: Proceedings of the Second Joint EuroHaptics Conference and Symposium on Haptic Interfaces for Virtual Environment and Teleoperator Systems (2007)

Earlier work with a 1-D tactile transducer demonstrated that lateral skin deformation is sufficient to produce sensations similar to those felt when brushing a finger against a line of Braille dots. Here, we extend this work to the display of complete 6-dot Braille characters using a general purpose 2-D tactile transducer called STReSS2. The legibility of the produced Braille was evaluated by asking seven expert Braille readers to identify meaningless 5-letter strings as well as familiar words. Results indicate that reading was difficult but possible for most individuals. The superposition of texture to the sensation of a dot improved performance. The results contain much information to guide the design of a specialized Braille display operating by lateral skin deformation. They also suggest that rendering for contrast rather than realism may facilitate Braille reading when using a weak tactile transducer.
Well: a language-agnostic foundation for compact and inherently safe mobile code
Authors: Michael Franz
Venue:  (2006)

This dissertation is inspired by the desire to enable the safe, flexible, and efficient transport of programs. The traditional solution to this problem is to compile the program into some lower-level representation, such as bytecode or machine code. This is unsatisfactory mainly because it ties the code format to a specific machine model and because it is impossible for the code receiver to verify safety properties and annotations at the appropriate level of abstraction. In this dissertation we present the WELL framework for mobile code specification and compression. WELL generalizes abstract syntax trees to static semantic trees (SSTs). SSTs are built according to a static semantic specifications (SSSs), which are a novel kind of higher-order data type with binding specifications. We establish a direct correspondence between SSTs and proofs and use it, for example, to present an adequate specification of System F. In an effort to make the specification of common programming language constructs such as Scheme's letrec practically feasible we introduce a new finitary binding concept. In WELL each SSS corresponds to a pair of encoding and decoding functions. On a logical level, the encoding function maps SSTs to their G&ouml;del number and the decoding function maps such numbers, i.e., bit strings or files, back to SSTs. The decoded SST exhibits by construction all the properties mandated by its SSS, in particular, its corresponding proof. Interestingly, the inherent safety feature does not necessarily increase program representation size. On the contrary, we are able to exploit the constraints specified in the SSS to significantly enhance the compression of SSTs. To this end, we adapted a statistical compression technique, namely prediction by partial match (PPM), to operate naturally on SSTs and to benefit from the knowledge of the SSS. Using compressed SSTs we are able to improve the compression of Java programs by 15--60% over the best know Java-specific compression technique. Furthermore, we present a new variation of escape analysis, whose results can be encoded as safe code annotations. Finally, we propose WELL as the foundation for a new code distribution infrastructure.
A posteriori probability source localization in an uncertain shallow water environment (Hudson Canyon)
Authors: L. W. Nolte
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1996. on Conference Proceedings., 1996 IEEE International Conference - Volume 02 (1996)

A wideband optimum uncertain field processor (OUFP) is presented, which when combined with Monte Carlo techniques, provides a computationally efficient and robust technique for matched-field processing (MFP). Under a simulated Hudson Canyon environment, a quantitative, probabilistic analysis of the sensitivity of matched field processing, assuming a known ocean (OMFP), to various kinds of environmental mismatch is shown. Similarly, the performance of the OUFP is calculated. Finally, it is shown that the localization performance of the wideband OUFP and the suboptimum Bartlett processor are in very good agreement with the performance predicted from the simulation results.
Object-oriented pattern-based parallel programming with automatically generated frameworks
Authors: Steve MacDonald, Duane Szafron, Jonathan Schaeffer
Venue: Proceedings of the 5th conference on USENIX Conference on Object-Oriented Technologies & Systems - Volume 5 (1999)

The CO2P3S parallel programming system uses design patterns and object-oriented programming to reduce the complexities of parallel programming. The system generates correct frameworks from pattern template specifications and provides a layered programming model to address both the problems of correctness and openness. This paper describes the highest level of abstraction in CO2P3S, using two example programs to demonstrate the programming model and the supported patterns. Further, we introduce phased parallel design patterns, a new class of patterns that allow temporal phase relationships in a parallel program to be specified, and provide two patterns in this class. Our results show that the frameworks can be used to quickly implement parallel programs, reusing sequential code where possible. The resulting parallel programs provide substantial performance gains over their sequential counterparts.
Business models and financial impacts of future mobile broadband networks
Authors: Erik Bohlin
Venue: Telematics and Informatics (2007)

This paper presents a financial simulation of a future 4G mobile network. The simulation suggests that the average revenue per user required to break even will be considerably lower than break-even level for 3G networks. Sensitivity analyses suggest that certain variables will have considerable impact on profitability. In particular, policies for spectrum management may the most sizeable critical impact.
A Novel Session Recovery Mechanism for Cluster-based Signaling Architecture for Conferencing in MANETs
Authors: Chunyan Fu, Roch Glitho, Ferhat Khendek
Venue: Proceedings of the 27th International Conference on Distributed Computing Systems Workshops (2007)

Mobile Ad hoc NETworks (MANETs) are networks that do not require pre-configuration. Nodes in MANETs are arbitrarily connected with wireless links. Detecting and handling link/node failures is a challenging issue in MANETs. Many solutions have been proposed. However, only a few of them can be directly used at the application layer. Conferencing in MANETs includes a set of "killer' applications, such as audio/video conferencing, gaming and distance-learning. Signaling is a critical component of conferencing. It handles conference session's initiation, modification and termination. We have recently proposed a cluster-based signaling architecture for conferencing in MANETs. However the architecture does not address the unintentional departures of participants from the conference caused by link and/or node failures. This paper aims at tackling this issue. A novel session recovery mechanism is proposed. It is based on the well known concept of heartbeat. We modeled and partially validated the recovery formalism using Promela/SPIN.
A directory index for Ext2
Authors: Daniel Phillips
Venue: Proceedings of the 5th annual Linux Showcase & Conference - Volume 5 (2001)

In recent years, filesystem designers have tended to favor the use of BTrees and variants thereof to eliminate directory performance bottlenecks. The idea of adding BTree directory indexing to Linux's Ext2 filesystem has been much discussed but never implemented, more probably due to an aversion to complexity than any laziness on the part of developers. Recently, I conceived and implemented a new kind of indexing technique using hashed keys held in a uniform-depth tree. I gave this structure the name "HTree". Compared to a BTree, the HTree has a considerable simpler implementation but offers similar performance. Furthermore, it turned out to be possible to achieve not only backward compatibility with existing Ext2 filesystems, but forward compatibility with earlier versions of Linux as well.