ppxscal/embedding_network huggingface dataset:
The Neurophysiological Basis of the Auditory Continuity Illusion: A Mismatch Negativity Study
Authors: Christophe Micheyl, Robert P. Carlyon, Yury Shtyrov, Olaf Hauk, Tara Dodson, Friedemann Pullvermüller
Venue: Journal of Cognitive Neuroscience (2003)

A sound turned off for a short moment can be perceived as continuous if the silent gap is filled with noise. The neural mechanisms underlying this "continuity illusion" were investigated using the mismatch negativity (MMN), an event-related potential reflecting the perception of a sudden change in an otherwise regular stimulus sequence. The MMN was recorded in four conditions using an oddball paradigm. The standards consisted of 500-Hz, 120-msec tone pips that were either physically continuous (Condition 1) or were interrupted by a 40-msec silent gap (Condition 2). The deviants consisted of the interrupted tone, but with the silent gap filled by a burst of bandpass-filtered noise. The noise either occupied the same frequency region as the tone and elicited the continuity illusion (Conditions 1a and 2a), or occupied a remote frequency region and did not elicit the illusion (Conditions 1b and 2b). We predicted that, if the continuity illusion is determined before MMN generation, then, other things being equal, the MMN should be larger in conditions where the deviants are perceived as continuous and the standards as interrupted or vice versa, than when both were perceived as continuous or both interrupted. Consistent with this prediction, we observed an interaction between standard type and noise frequency region, with the MMN being larger in Condition 1a than in Condition 1b, but smaller in Condition 2a than in Condition 2b. Because the subjects were instructed to ignore the tones and watch a silent movie during the recordings, the results indicate that the continuity illusion can occur outside the focus of attention. Furthermore, the latency of the MMN (less than approximately 200 msec postdeviance onset) places an upper limit on the stage of neural processing responsible for the illusion.
Stability Region Based Expectation Maximization for Model-based Clustering
Authors: Chandan K. Reddy, Hsiao-Dong Chiang, Bala Rajaratnam
Venue: Proceedings of the Sixth International Conference on Data Mining (2006)

In spite of the initialization problem, the Expectation- Maximization (EM) algorithm is widely used for estimating the parameters in several data mining related tasks. Most popular model-based clustering techniques might yield poor clusters if the parameters are not initialized properly. To reduce the sensitivity of initial points, a novel algorithm for learning mixture models from multivariate data is introduced in this paper. The proposed algorithm takes advantage of TRUST-TECH (TRansformation Under STability-reTaining Equilibra CHaracterization) to compute neighborhood local maxima on likelihood surface using stability regions. Basically, our method coalesces the advantages of the traditional EM with that of the dynamic and geometric characteristics of the stability regions of the corresponding nonlinear dynamical system of the log-likelihood function. Two phases namely, the EM phase and the stability region phase, are repeated alternatively in the parameter space to achieve improvements in the maximum likelihood. Though applied to Gaussian mixtures in this paper, our technique can be easily generalized to any other parametric finite mixture model. The algorithm has been tested on both synthetic and real datasets and the improvements in the performance compared to other approaches are demonstrated. The robustness with respect to initialization is also illustrated experimentally.
Restoration Strategies In Mesh Optical Networks: Cost Vs. Service Availability
Authors: Daniel R. Jeske, Ashwin Sampath
Venue: Proceedings of the 12th Pacific Rim International Symposium on Dependable Computing (2006)

Availability is an important attribute of optical transport networks, and is enabled through many alternative restoration schemes. Different restoration schemes tradeoff network cost, as measured by provisioned capacity, and network reliability to match diverse application needs. We provide a systematic quantification of these tradeoffs for commonly employed restoration schemes and illustrate them for several networks. In this paper, we analyze a dedicated capacity 1+1 protection scheme and two commonly employed shared capacity mesh restoration schemes: path and link based restoration.
Collective tree exploration
Authors: Pierre Fraigniaud, Leszek Gąsieniec, Dariusz R. Kowalski, Andrzej Pelc
Venue: Networks (2006)

An n-node tree has to be explored by k mobile agents (robots), starting at its root. Every edge of the tree must be traversed by at least one robot, and exploration must be completed as fast as possible. Even when the tree is known in advance, scheduling optimal collective exploration turns out to be NP-hard. We investigate the problem of how communication among robots influences the time for exploring unknown trees. To this end, we consider two scenarios. In the first scenario, robots can communicate by writing at the currently visited node previously acquired information, and reading information available at this node. In the second scenario robots are oblivious of one another, and each of them knows only the part of the tree previously explored by itself. We show that this difference of communication capability significantly influences time of collective exploration. Under the first scenario, we construct an exploration algorithm whose running time for any tree is only O(k&sol; log k) larger than the optimal exploration time with full knowledge of the tree, while under the second scenario we prove that every algorithm works in time &Omega;(k) larger than optimal, for some trees. &copy; 2006 Wiley Periodicals, Inc. NETWORKS, Vol. 48(3), 166&ndash;177 2006
Error sensitivity analysis of a bandwidth expansion technique in spectral analysis
Authors: W. S. McCormick
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1995. on International Conference - Volume 02 (1995)

The paper presents an error sensitivity analysis of a bandwidth expansion technique in spectral analysis based on a noise-protected version of the Chinese Remainder Theorem. Necessary and sufficient conditions on remainder percent error and sampling period/time delay error are derived using various properties from number theory. The developed design criteria have special relevance to real-time, wide bandwidth spectral estimation in the EW passive receiver. 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
The Effects of Case Mixing on Word Recognition: Evidence from a PET Study
Authors: Kate Mayall, Glyn W. Humphreys, Andrea Mechelli, Andrew Olson, Cathy J. Price
Venue: Journal of Cognitive Neuroscience (2001)

The early stages of visual word recognition were investigated by scanning participants using PET as they took part in implicit and explicit reading tasks with visually disrupted stimuli. CaSe MiXiNg has been shown in behavioral studies to increase reaction times (RTs) in naming and other word recognition tasks. In this study, we found that during both an implicit (feature detection) task and an explicit word-naming task, mixed-case words compared to same-case words produced increased activation in an area of the right parietal cortex previously associated with visual attention. No effect of case was found in this area for pseudowords or consonant strings. Further, lowering the contrast of the stimuli slowed RTs as much as case mixing, but did not lead to the same increase in right parietal activation. No significant effect of case mixing was observed in left-hemisphere language areas. The results suggest that reading mixed-case words requires increased attentional processing. However, later word recognition processes may be relatively unaffected by the disruption in presentation.
Greedy algorithms for on-line set-covering and related problems
Authors: Giorgio Ausiello, Aristotelis Giannakos, Vangelis Th. Paschos
Venue: Proceedings of the 12th Computing: The Australasian Theroy Symposium - Volume 51 (2006)

We study the following on-line model for set-covering: elements of a ground set of size n arrive one-by-one and with any such element ci, arrives also the name of some set Si0 containing ci and covering the most of the uncovered ground set-elements (obviously, these elements have not been yet revealed). For this model we analyze a simple greedy algorithm consisting of taking Si0 into the cover, only if ci is not already covered. We prove that the competitive ratio of this algorithm is √n and that it is asymptotically optimal for the model dealt, since no on-line algorithm can do better than √n/2. We next show that this model can also be used for solving minimum dominating set with competitive ratio bounded above by the square root of the size of the input graph. We finally deal with the maximum budget saving problem. Here, an initial budget is allotted that is destined to cover the cost of an algorithm for solving set-covering. The objective is to maximize the savings on the initial budget. We show that when this budget is at least equal to √n times the size of the optimal (off-line) solution of the instance under consideration, then the natural greedy off-line algorithm is asymptotically optimal.
Independent Moving Object Detection Using a Colour Background Model
Authors: Fabian Campbell-West, Paul Miller, Hongbin Wang
Venue: Proceedings of the IEEE International Conference on Video and Signal Based Surveillance (2006)

An independent moving objection detection system is described which uses a colour background model for a nonstationary sensor. Over time the RGB distribution of a static point in a scene, observed from a static or moving camera, is cylindrical rather than spherical and is modelled as such. The background model is recursively updated over time and is robustly aligned to the most recent frame. Discrepancies between the current observed frame and the background model are considered foreground events and are determined using a classification framework which combines per-pixel colour and brightness differences. In principle the colour (RGB) images provide greater discriminative power than greyscale (brightness). However for several sequences tested, which are of road scenes from an airborne sensor, it was found that the colour information did not improve the classification of foreground pixels significantly.
Structured eLearning for Depth
Authors: Masha Etkind, Uri Shafrir
Venue: Proceedings of the Sixth IEEE International Conference on Advanced Learning Technologies (2006)

In this presentation we describe a new pedagogy that focuses learners' attention on deep comprehension of the conceptual content of learned material. Two new eLearning tools are described in some detail: Interactive Concept Discovery (InCoD) Learning; and Meaning Equivalence Reusable Learning Objects (MERLO). These semantic technologies were developed at Ontario Institute for Studies in Education and Resource Centre for Academic Technology of University of Toronto, and tested since 2001 in several academic institutions in Canada and at the Russian Academy of Sciences (patents pending). We describe the rationale for developing these instructional tools; their main characteristics; and results of several evaluative implementations that demonstrate their potential to enhance learning outcomes and to provide authentic, credible, evidence-based formative and summative assessments of learning processes.
Spectral problems with mixed Dirichlet-Neumann boundary conditions: isospectrality and beyond
Authors: Dmitry Jakobson, Michael Levitin, Nikolai Nadirashvili, Iosif Polterovich
Venue: Journal of Computational and Applied Mathematics (2006)

Consider a bounded domain with the Dirichlet condition on a part of the boundary and the Neumann condition on its complement. Does the spectrum of the Laplacian determine uniquely which condition is imposed on which part? We present some results, conjectures and problems related to this variation on the isospectral theme.
Technology supported collaborative learning for higher education: comparative case studies in Tanzania
Authors: Gert-Jan de Vreede, Rabson J. S. Mgaya
Venue: Information Technology for Development (2006)

To learn, a person has to be able to communicate effectively with others about the knowledge to be learned. Communication processes in classrooms can be supported by Group Support Systems (GSS), that enable students to communicate anonymously and in parallel. Group Support Systems experiences suggest that the technology increases observed learning, self-reported learning, on-task participation, and satisfaction with the learning experience. The authors discuss case studies from higher education in Tanzania. The particular benefit of GSS in this environment was threefold: First, it encouraged meaningful interaction among students and between students and teachers. Local culture normally hinders this. Second, it allowed all participants to discuss sensitive topics freely. Finally, it exposed students to collaborative technologies that are expected to play a pivotal role in (global) collaborative development activities. Clearly, the use of collaborative technologies enables the participation of a broader range of students.
Skolem Functions and Herbrand Universes in a Tree Generalization of First Order Logic
Authors: Roger Villemaire, Sylvain Halle, Rudy Deca, Omar Cherkaoui
Venue: Proceedings of the Fifth Mexican International Conference on Artificial Intelligence (2006)

Skolem functions and Herbrand universes are fundamental concepts in first-order logic that form the basis of many works in artificial intelligence. In this paper, we study a fragment of the XML Query Language (XQuery) that generalizes first-order logic to a setting where variables form a forest instead of a set. A formal description of the logic and its semantics is given; Skolem functions and Herbrand universes are generalized to this setting.
A string extension for Pascal
Authors: F. D. Boswell, M. J. Carmody, T. R. Grove
Venue: ACM SIGSMALL Newsletter (1982)

The Pascal language, as defined by the ISO Third Draft Proposal or Jensen and Wirth (in the Pascal User Manual and Report (Second Edition)), does not facilitate the manipulation of character strings. Standard Pascal defines a string type to be simply a fixed-length array of characters. This definition is, of course, adequate from a theoretic point of view, but leads to several problems for the Pascal programmer from a practical viewpoint.
A board game for teaching internet engineering
Authors: Peter Komisarczuk, Ian Welch
Venue: Proceedings of the 8th Austalian conference on Computing education - Volume 52 (2006)

This paper describes elements in the development of a board game for teaching Internet peering as part of an Internet engineering class.
Secure access to IP multimedia services using generic bootstrapping architecture (GBA) for 3G & beyond mobile networks
Authors: Muhammad Sher, Thomas Magedanz
Venue: Proceedings of the 2nd ACM international workshop on Quality of service security for wireless and mobile networks (2006)

The IP Multimedia Subsystem (IMS) defined by Third Generation Partnership Projects (3GPP and 3GPP2) is a technology designed to provide robust multimedia services across roaming boundaries and over diverse access technologies with promising features like quality-of-service (QoS), reliability and security. The IMS defines an overlay service architecture that merges the paradigms and technologies of the Internet with the cellular and fixed telecommunication worlds. Its architecture enables the efficient provision of an open set of potentially highly integrated multimedia services, combining web browsing, email, instant messaging, presence, VoIP, video conferencing, application sharing, telephony, unified messaging, multimedia content delivery, etc. on top of possibly different network technologies. As such IMS enables various business models for providing seamless business and consumer multimedia applications. In this communication converged world, the challenging issues are security, quality of service (QoS) and management & administration. In this paper our focus is to manage secure access to multimedia services and applications based on SIP and HTTP on top of IP Multimedia Subsystem (IMS). These services include presence, video conferencing, messaging, video broadcasting, and push to talk etc. We will utilize Generic Bootstrapping Architecture (GBA) model to authenticate multimedia applications before accessing these multimedia services offered by IMS operators. We will make enhancement in GBA model to access these services securely by introducing Authentication Proxy (AP) which is responsible to implement Transport Layer Security (TLS) for HTTP and SIP communication. This research work is part of Secure Service Provisioning (SSP) Framework for IP Multimedia System at Fokus Fraunhofer IMS 3Gb Testbed
Comparing energy-saving MAC protocols for wireless sensor networks
Authors: G. P. Halkes, T. van Dam, K. G. Langendoen
Venue: Mobile Networks and Applications (2005)

Applications for wireless sensor networks have notably different characteristics and requirements from standard WLAN applications. Low energy consumption is the most important consideration. The low message rate that is typical for sensor network applications and the relaxed latency requirements allow for significant reductions in energy consumption of the radio. In this article we study the energy saved by two MAC protocols optimized for wireless sensor networks, S-MAC and T-MAC, in comparison to standard CSMA/CA, We also report on the effects of low-power listening, a physical layer optimization, in combination with these MAC protocols. The comparison is based on extensive simulation driven by traffic that varies over time and location; sensor nodes are inactive unless they observe some physical event, or send status updates to the sink node providing the connection to the wired world. T-MAC in combination with low-power listening saves most energy, but can not handle the same peak loads as CSMA/CA and S-MAC.
The Ubiquitous Museum Learning Environment: Concept, Design, Implementation, and a Case Study
Authors: Tsung-Yu Liu, Tan-Hsu Tan, Yu-Ling Chu
Venue: Proceedings of the Sixth IEEE International Conference on Advanced Learning Technologies (2006)

Many problems have been found in museum learning activities that apply tour guide systems. In this research, a ubiquitous museum learning environment is developed to overcome these problems by applying the radio frequency identification, wireless network, and embedded system technologies. A case study is conducted and experimental results verify the effectiveness of the proposed learning environment.
Decoherence in Holonomic Quantum Computation
Authors: Giuseppe Florio
Venue: Open Systems Information Dynamics (2006)

Geometric phases are an interesting field of research in quantum mechanics. Recently both abelian and nonabelian geometric phases have been proposed as a useful resource for the experimental implementation of quantum computation. In this paper we focus on a particular physical model and study the effect of a bosonic bath on a class of holonomic transformations. We write a general master equation for time-dependent Hamiltonians and derive analytical and numerical solutions for the system considered. The fidelity is analyzed in the adiabatic and nonadiabatic regime. We also determine an optimal finite operation time for this class of gates.
Analysis of traceback techniques
Authors: Udaya Kiran Tupakula, Vijay Varadharajan
Venue: Proceedings of the 2006 Australasian workshops on Grid computing and e-research - Volume 54 (2006)

Today's Internet is extremely vulnerable to Distributed Denial of service (DDoS) attacks. There is tremendous pressure on the sites performing online business and ISP's to protect their networks from DDoS attacks. Recently, several novel traceback techniques have been proposed to trace the approximate spoofed source of attack. Each proposed traceback technique has some unique advantages and disadvantages over the others. In this paper we will consider some of the novel traceback techniques and focus our discussion i) to raise some of the real time issues that can be addressed in the further research and ii) from the attackers perspective on how to generate DDoS attacks and remain untraced even if any of the traceback technique is deployed in the Internet. We will also demonstrate how attacks can be further amplified if ICMP traceback technique is deployed in the Internet and discuss techniques to minimise the additional attack traffic. We believe that the networks tend to become complex and more vulnerable to DDoS attacks if some of the proposed traceback techniques are deployed in the Internet.
A Formal Framework for Component Pr otocols Behavioural Compatibility
Authors: Nabil Hameurlain
Venue: Proceedings of the XIII Asia Pacific Software Engineering Conference (2006)

In this paper, we present a new and optimistic approach to the definition of component protocols compatibility, and we provide a framework for modeling component protocols together with their composition. This framework is discussed in terms of compatibility and substitutability checks of protocols. According to the optimistic approach, two protocols are compatible if they are composable and their composition leads to a usable protocol, that is a protocol such that there exists an environment ensuring safety and liveness property of the composed protocol, which is obtained by the composition of the involved protocol and that environment. Safety and liveness properties such as deadlock-freeness and proper termination of protocols are considered up to different extents. Based on that, we present two protocols compatibility relations related to the usability concept, together with two behavioural subtyping relations related to the principle of substitutability. We address their soundness by showing the existing link between compatibility and substitutability relations, which have found necessary when dealing with incremental design of protocols.
Racial disparities in health information access: resilience of the digital divide
Authors: Daniel P. Lorence, Heeyoung Park, Susannah Fox
Venue: Journal of Medical Systems (2006)

Policy initiatives of the late 1990s were believed to have largely eliminated the information "Digital Divide." For healthcare consumers, access to information is an essential part of the consumer-centric framework outlined in the recently proposed national health information initiative. This study sought to examine how racial/ethnic characteristics are associated with Internet use and online health information. Using a cross-sectional nationwide study of reported Internet use and information search in 2000 and 2002, we studied a stratified sample of computer users from the Pew Internet American Life Project surveys. Adjusted estimates of race/ethnicity and income effects on Internet use and search behaviors were derived from generalized estimating equations. Results show wide gaps in the use of computers between Hispanics and Whites (OR = 0.593 [0.440, 0.798]) and between African-Americans and Whites (OR = 0.554 [0.427, 0.720]) in 2000 significantly narrowed in 2002 (OR of Hispanic to white = 1.250 [0.874, 1.789]; OR of African-American to Whites = (0.793 [0.551, 1.141]). Gaps in access to the Internet, however, remained consistent between 2000---2002. Differences in health information seeking between Hispanics and Whites existed in both 2000 and 2002. 56% of White Internet users at some time searched for online health information, whereas 42% of Hispanic Internet users did so in 2000. By 2002, these percentages had increased to 13.4 and 15.8%, respectively. Data highlight the persistence of "Digitally Underserved Groups," despite recent Divide reduction strategies.