ppxscal/embedding_network huggingface dataset:
Feedback control for a heat equation under a white-noise excitation
Authors: A. Bratus, A. P. Ivanova
Venue: Proceedings of the 2003 International Conference on Physics and Control - Volume 4 (2003)

An optimal feedback control problem for a heat conduction equation under white-noise random excitation is considered. The problem is to minimize expected response for integral value of squared difference among current and preassigned temperature during a given time instant T. The control forces are concentrated in the fixed points (heat actuators). The magnitude of control forces are restricted by positive values. Using dynamic programming method this problem can be reduced to the Couchy problem for Hamilton-Jacobi-Bellman (HJB) partial nonlinear differential equation for a Bellman function H in unbounded domain. Specifically, an exact analytical solution has been obtained within a certain unbounded outer domain on the phase plane, which provides necessary boundary conditions for numerical solution within a bounded (finite) inner domain, thereby alleviating problem of numerical analysis for an unbounded domain. The size of outer domain can be chosen such way that the values of Bellman function H and its corresponding derivatives will coincide in the boundary of outer and inner domains. As an example the case of control problem for one heat actuator in the rod is considered.
Classical symmetric functions in superspace
Authors: Patrick Desrosiers, Luc Lapointe, Pierre Mathieu
Venue: Journal of Algebraic Combinatorics: An International Journal (2006)

We present the basic elements of a generalization of symmetric function theory involving functions of commuting and anticommuting (Grassmannian) variables. These new functions, called symmetric functions in superspace, are invariant under the diagonal action of the symmetric group on the sets of commuting and anticommuting variables. In this work, we present the superspace extension of the classical bases, namely, the monomial symmetric functions, the elementary symmetric functions, the completely symmetric functions, and the power sums. Various basic results, such as the generating functions for the multiplicative bases, Cauchy formulas, involution operations as well as the combinatorial scalar product are also generalized.
Investigating Response Bias in an Information Technology Survey of Physicians
Authors: Nir Menachemi, Neset Hikmet, Mary Stutzman, Robert G. Brooks
Venue: Journal of Medical Systems (2006)

Monitoring the diffusion of electronic health records (EHR) into ambulatory clinical practice has important policy implications. However, estimates of EHR use are typically derived from survey data and may be subject to significant response bias. The current study is a retrospective analysis testing for response bias in a large information technology survey of physicians (n=14,921). To detect bias, respondents were compared to nonrespondents on known characteristics. Moreover, early respondents were compared to late respondents with respect to key variables in the survey that are likely to influence participation. The 4203 respondents (28.2% participation rate) did not differ demographically from nonrespondents. Response rates, by specialty, differed slightly. When comparing early and late survey respondents, no differences were detected in EHR use, length of time since EHR installation, practice size, physician age, years since medical school graduation, and years of practice in their current community. Overall, response bias was not detected using established methodologies in this mailed survey of physician EHR use. Similar surveys of physicians, even with a lower than expected response rate, may still be valid.
Enhanced PCF Protocols for Real-time Multimedia Services over 802.11 Wireless Networks
Authors: Ming-Chuan Hsu, Yaw-Chung Chen
Venue: Proceedings of the 26th IEEE International ConferenceWorkshops on Distributed Computing Systems (2006)

In wireless network environment, different traffic classes exhibit a variety of characteristics and service requirements [4,5,7], such as data rate, maximum tolerable packet error rate and delay bounds. Although IEEE 802.11e [9,10] addresses the QoS issues and classifies the traffic into four prioritized access categories, there is still no guarantee of real-time transmission service due to the lack of an effective coordinating mechanism [11] among contending clients and a satisfactory scheduling method for various delay-sensitive packets from multiple traffic flows. In this work, we propose a nearly complete polling list solution to IEEE 802.11 WLAN by enhancing the original PCF protocol with better demand assignment features. A flexible and fair polling list method among the various time bounds is investigated in the proposed scheme. The performance evaluation based on NS-2 network simulator [12,13] shows that our schemes are well suited for variable bit rate service in real-time multimedia applications.
Patterns Approach in the Re-Engineering Process of Learning Scenario
Authors: Noa Randriamalaka, Sebastien Iksal
Venue: Proceedings of the Sixth IEEE International Conference on Advanced Learning Technologies (2006)

This paper presents a knowledge capitalization methodology, which is proposed inside a project concerning the assistance in the learning scenarios' design process, which is based on designers' expertise. The community of designers has an important knowledge on the design of learning resources (scenarios...) and learning session. But this expertise is never capitalized and shared. Designers cannot use and re-use it to facilitate their activity. Our work focuses on the detection, the capitalization, and the re-use of this knowledge in order to support design activity.
Computer support for children's collaborative fantasy play and storytelling
Authors: Kimiko Ryokai, Justine Cassell
Venue: Proceedings of the 1999 conference on Computer support for collaborative learning (1999)

Collaborative fantasy play and storytelling serve an important role in preschool children's development. Making up characters and telling stories are activities through which children make sense of and test their hypotheses about the world. While computers are increasingly present to support young children's collaboration in school tasks, there is a lack of computational systems to support children's voice in this kind of important collaborative activity.StoryMat is a system that supports children's collaborative fantasy play and storytelling. With StoryMat, however, collaboration can take place among co-present peers, or between a child and a previous user, mediated by the StoryMat. StoryMat records and recalls children's own narrating voices and the movements they make with their toys on the mat. Stories from the past are conjured up on the mat as a narrating moving shadow of the toy, when they are triggered by the present stories that are similar. By hearing peer stories in response to their own story, children's stories and the experience of telling them seem to become richer. This paper addresses the importance of supporting children's collaboration in fantasy play and storytelling and suggests a new way for technology to play an integral part in that activity.
Oscillation of linear ordinary differential equations: on a theorem of A. Grigoriev
Authors: Sergei Yakovenko
Venue: Journal of Dynamical and Control Systems (2006)

We give a simplified proof and an improvement of a recent theorem of A. Grigoriev, placing an upper bound for the number of roots of linear combinations of solutions of systems of linear equations with polynomial or rational coefficients.
A Novel Linear Feedback Control Approach of Lorenz Chaotic System
Authors: Zongmin Qiao, Jiaxing Cheng
Venue: Proceedings of the International Conference on Computational Inteligence for Modelling Control and Automation and International Conference on Intelligent Agents Web Technologies and International Commerce (2006)

In chaos control fields, the nonfeedback and the nonlinear feedback approaches are inevitable much less flexible. However linear feedback controllers are easy to implement, especially in electrical systems. In this paper, based on linear feedback control strategy and Lyapunov stability theory, some effective linear feedback controllers of variable states are given which can realize the control purposes of unstable equilibriums by a dislocated adaptive control of variables x and y. A numerical example is given to illuminate the design procedure and advantage of the results derived. It is noted that in principle, the dislocated adaptive control approaches developed in this paper can be applied to general smooth chaotic systems satisfying some mild required properties such as Chen system, lu.... system, etc.
Dynamic connectivity management with an intelligent route service control point
Authors: J. Van der Merwe, A. Cepleanu, K. D'Souza, B. Freeman, A. Greenberg, D. Knight, R. McMillan, D. Moloney, J. Mulligan, H. Nguyen, M. Nguyen, A. Ramarajan, S. Saad, M. Satterlee, T. Spencer, D. Toll, S. Zelingher
Venue: Proceedings of the 2006 SIGCOMM workshop on Internet network management (2006)

Increased use of demanding network applications, as well as the increase of unwanted network traffic in the form of DDoS attacks, are putting new pressures on service providers to meet the expectations of customers in terms of network availability and performance. Providers are expected to deal with potential problems in near real-time fashion. Further, many of these demanding application, such as VoIP and online gaming, are very sensitivity to even small periods of disruption. In this work we therefore specifically focus on dynamic connectivity management, which we broadly define as the ability to dynamically manage how and where traffic flows across a network. Because it is intimately involved with how traffic flows through the network, BGP would be an ideal candidate for many of these management tasks. Unfortunately, BGP is itself a complicated protocol and up to now the prospect of using it to perform routine management tasks has not been considered a feasible approach. In this paper we show how the simplification introduced by a centralized Intelligent Route Service Control Point (IRSCP) that allows route selection to be performed outside the routers and also allows such route selection to be informed by external network intelligence, address this quandary. We present several examples of connectivity management tasks that can benefit from our approach. We describe our trial implementation of the IRSCP and show how our approach raise the level of abstraction, allowing operators to focus on what functions need to be performed, rather than getting bogged down with how to perform them.
Toward a model of the everyday life information needs of urban teenagers, Part 2: Empirical model: Research Articles
Authors: Denise E. Agosto, Sandra Hughes-Hassell
Venue: Journal of the American Society for Information Science and Technology (2006)

This is the second part of a two-part article that presents a theoretical and an empirical model of the everyday life information needs of urban teenagers. Part 2 focuses on the derivation of the empirical model and on its relationship to the theoretical model presented in Part 1. Part 2 also provides examples from the project data to support each of the components of the empirical model, which ties 28 information needs topics to the seven independent variables in the theoretical model. Comparison of the empirical model to the results of past youth information behavior research shows that the participants in this study tended to have the same types of information needs as previous researchers have found with more advantaged, nonminority groups of teens. This finding is significant because it suggests that teenagers have similar information needs across socioeconomic, ethnic, cultural, and geographic boundaries. Due to the exploratory nature of this study, however, additional research is necessary to confirm this possibility. &copy; 2006 Wiley Periodicals, Inc.
Universal Access and Content Adaptation in Mobile Learning
Authors: Stephen J. H. Yang, Irene Y. L. Chen
Venue: Proceedings of the Sixth IEEE International Conference on Advanced Learning Technologies (2006)

Universal access is known as the concept of facilitating accesses to the desired data according to the varying capabilities and characteristics of users [1]. Universal access aims to be capable of recognizing and responding to the presence of different context in a seamless, unobtrusive and often invisible way. To achieve this goal, two important issues need to be solved, they are context awareness and content adaptation. In this paper, context is referred to as contextual information that can be used to characterize the situation of an entity where an entity can be a person, a place, a physical or computational object [2]. The contextual information can be where and when the users are (time and space), as well as what the content are available nearby, and etc.
Working Memory Maintenance Contributes to Long-term Memory Formation: Neural and Behavioral Evidence
Authors: Charan Ranganath, Michael X. Cohen, Craig J. Brozinsky
Venue: Journal of Cognitive Neuroscience (2005)

Theories of human memory have led to conflicting views regarding the relationship between working memory ( WM) maintenance and episodic long-term memory (LTM) formation. Here, we tested the prediction that WM maintenance operates in two stages, and that processing during the initial stage of WM maintenance promotes successful LTM formation. Results from a functional magnetic resonance imaging study showed that activity in the dorsolateral prefrontal cortex and hippocampus during the initial stage of WM maintenance was predictive of subsequent LTM performance. In a behavioral experiment, we demonstrated that interfering with processing during the initial stage of WM maintenance impaired LTM formation. These results demonstrate that processing during the initial stage of WM maintenance directly contributes to successful LTM formation, and that this effect is mediated by a network that includes the dorsolateral prefrontal cortex and the hippocampus.
Characterization of Empathy Deficits following Prefrontal Brain Damage: The Role of the Right Ventromedial Prefrontal Cortex
Authors: S. G. Shamay-Tsoory, R. Tomer, B. D. Berger, J. Aharon-peretz
Venue: Journal of Cognitive Neuroscience (2003)

Impaired empathic response has been described in patients following brain injury, suggesting that empathy may be a fundamental aspect of the social behavior disturbed by brain damage. However, the neuroanatomical basis of impaired empathy has not been studied in detail. The empathic response of patients with localized lesions in the prefrontal cortex (n = 25) was compared to responses of patients with posterior (n = 17) and healthy control subjects (n = 19). To examine the cognitive processes that underlie the empathic ability, the relationships between empathy scores and the performance on tasks that assess processes of cognitive flexibility, affect recognition, and theory of mind (TOM) were also examined. Patients with prefrontal lesions, particularly when their damage included the ventromedial prefrontal cortex, were significantly impaired in empathy as compared to patients with posterior lesions and healthy controls. However, among patients with posterior lesions, those with damage to the right hemisphere were impaired, whereas those with left posterior lesions displayed empathy levels similar to healthy controls. Seven of nine patients with the most profound empathy deficit had a right ventromedial lesion. A differential pattern regarding the relationships between empathy and cognitive performance was also found: Whereas among patients with dorsolateral prefrontal damage empathy was related to cognitive flexibility but not to TOM and affect recognition, empathy scores in patients with ventromedial lesions were related to TOM but not to cognitive flexibility. Our findings suggest that prefrontal structures play an important part in a network mediating the empathic response and specifically that the right ventromedial cortex has a unique role in integrating cognition and affect to produce the empathic response.
Picture languages: tiling systems versus tile rewriting grammars
Authors: Alessandra Cherubini, Stefano Crespi Reghizzi, Matteo Pradella, Pierluigi San Pietro
Venue: Theoretical Computer Science (2006)

Two formal models of pictures, i.e., two dimensional (2D) languages are compared: tiling systems and tile rewriting grammars, which resp. extend to 2D the regular and context-free languages. Two results extending classical language properties into 2D are proved. First, non-recursive tile writing grammars (TRG) coincide with tiling systems (TS). Second, non-self-embedding TRG are suitably defined as corner grammars, showing that they generate TS languages. The proofs exploit newly introduced language substitutions, also nested and iterated.
Design alternatives for scalable Web server accelerators
Authors: Junehwa Song
Venue: Proceedings of the 2000 IEEE International Symposium on Performance Analysis of Systems and Software (2000)

We study design alternatives for, and describe implementations and performance of, a scalable and highly available Web server accelerator. The accelerator runs under an embedded operating system and improves Web server performance by caching data. The basic design alternatives include a content router or a TCP router (without content routing) in front of a set of Web cache accelerator nodes, with the cache memory distributed across the accelerator nodes. Content based routing reduces cache node CPU cycles but can make the front-end router a bottleneck. With the TCP router, a request for a cached object may initially be sent to the wrong cache node; this results in larger cache node CPU cycles, but can provide a higher aggregate throughput, because the TCP router becomes a bottleneck at a higher throughput than the content router. Based on measurement of implementations, we quantify the throughput ranges in which different designs are preferable. We also examine a combination of content based and TCP routing techniques. We examine optimizations, such as different communication and data delivery methods, replication of hot objects, and cache replacement policies that take into account the fact that there might be different bottlenecks in the system at different times; depending upon which resource is likely to become a bottleneck, a different cache replacement algorithm is applied.
Transformation of XML data using updates without side effects
Authors: A. A. Boldakov, M. N. Grinev
Venue: Programming and Computing Software (2006)

One of the key technologies of XML data management is XQuery, the query language for both retrieving and transforming XML data. In the paper, limitations of the XQuery facilities for transforming XML data are discussed. It is shown that, for one important class of queries, XQuery expressions are too cumbersome and computationally inefficient. In the paper, it is suggested to extend the XQuery language by functional update expressions. From the syntax standpoint, such expressions are similar to expressions of XML update languages. However, they can be evaluated without side effects, which makes it possible to integrate them in XQuery in a natural way. The expressiveness of the extended language is demonstrated, and approaches to efficient implementation of the suggested extension are considered. In addition, the problem of arbitrary compositions of XML query and update expressions (the problem of nested update expressions) is discussed. The existing XML update languages are based, as a rule, on the XQuery language; however, the possibility of constructing arbitrary compositions of XQuery expressions and those of the XML update language is not provided. This impedes development of practical XML applications in the XQuery language. In the paper, an approach to solving the composition problem based on the use of functional update expressions is suggested. Possibilities of the implementation of the suggested extension are discussed.
Attention and Sensory Gain Control: A Peripheral Visual Process?
Authors: Todd C. Handy, Wayne Khoe
Venue: Journal of Cognitive Neuroscience (2005)

Attention-related sensory gain control in human extrastriate cortex is believed to improve the acuity of visual perception. Yet given wide variance in the spatial resolution of vision across the retina, it remains unclear whether sensory gain operates homogenously between foveal and nonfoveal retinotopic locations. To address this issue, we used event-related potentials (ERPs) in a variant of the canonical spatial attention task. Participants were cued to expect targets at either fixation (foveal targets) or at a location several degrees above fixation (parafoveal targets). At both target locations, manual reaction times were shorter for cued relative to uncued targets, indicating that attention was consistently oriented to the cued location. Nevertheless, attention-related increases in sensory-evoked cortical activity were only observed at the parafoveal target location, as measured by the amplitude of the lateral occipital P1 ERP component. A second experiment replicated this data pattern using targets with lower stimulus contrast, indicating that the absence of a P1 effect for foveal targets could not be attributed to a saturated P1 response under higher-contrast stimulus conditions. When considered in light of retinogeniculate projections to cortex showing systematic changes in their physiological organization beginning within a degree of visual angle of the fovea, our findings support the proposal that the strategic functions of visual attention may vary with the retinotopic location involved.
Contextualizing commitment protocol
Authors: Amit K. Chopra, Munindar P. Singh
Venue: Proceedings of the fifth international joint conference on Autonomous agents and multiagent systems (2006)

Commitment protocols are modularized specifications of interactions understood in terms of commitments. Purchase is a classic example of a protocol. Although a typical protocol would capture the essence of the interactions desired, in practice, it should be adapted depending on the circumstances or context and the agents' preferences based on that context. For example, when applying purchase in different contexts, it may help to allow sending reminders for payments or returning goods to obtain a refund. We contextualize a protocol by adapting it via different transformations.Our contributions are the following: (1) a protocol is transformed by composing its specification with a transformer specification; (2) contextualization is characterized operationally by relating the original and transformed protocols; and (3) contextualization is related to protocol compliance.
Introducing the Future of AI
Authors: James Hendler
Venue: IEEE Intelligent Systems (2006)

To explore our field's future, we invited a number of well-known AI scientists to contribute articles speculating about where AI is headed and how we might get there. This article is part of a special issue on the Future of AI.
New Hadamard matrices of order 4 p2 obtained from Jacobi sums of order 16
Authors: Ka Hin Leung, Siu Lun Ma, Bernhard Schmidt
Venue: Journal of Combinatorial Theory Series A (2006)

Let p ≡ 7 mod 16 be a prime. Then there are integers a, b, c, d with a ≡ 15 mod 16, b ≡ 0 mod 4, p2 = a2 + 2(b2 + c2 + d2), and 2ab = c2 - 2cd - d2. We show that there is a regular Hadamard matrix of order 4p2 provided that p = a ± 2b or p = a + δ12b + 4δ2c + 4δ1δ2d with δi = ±1.