ppxscal/embedding_network huggingface dataset:
A continuation BSOR-Lanczos-Galerkin method for positive bound states of a multi-component Bose-Einstein condensate
Authors: Shu-Ming Chang, Yuen-Cheng Kuo, Wen-Wei Lin, Shih-Feng Shieh
Venue: Journal of Computational Physics (2005)

We develop a continuation block successive over-relaxation (BSOR)-Lanczos-Galerkin method for the computation of positive bound states of time-independent, coupled Gross-Pitaevskii equations (CGPEs) which describe a multi-component Bose-Einstein condensate (BEC). A discretization of the CGPEs leads to a nonlinear algebraic eigenvalue problem (NAEP). The solution curve with respect to some parameter of the NAEP is then followed by the proposed method. For a single-component BEC, we prove that there exists a unique global minimizer (the ground state) which is represented by an ordinary differential equation with the initial value. For a multi-component BEC, we prove that m identical ground/bound states will bifurcate into m different ground/bound states at a finite repulsive inter-component scattering length. Numerical results show that various positive bound states of a two/three-component BEC are solved efficiently and reliably by the continuation BSOR-Lanczos-Galerkin method.
On the multi-radius cover problem
Authors: Julián Mestre
Venue: Information Processing Letters (2006)

An instance of the multi-radius cover problem consists of a graph G = (V, E) with edge lengths l: E → R+. Each vertex u ∈ V represents a transmission station for which a transmission radius ru must be picked. Edges represent a continuum of demand points to be satisfied, that is, for every edge (u, v) ∈ E we ask that ru + rv ≥ luv. The cost of transmitting at radius r from vertex u is given by an arbitrary non-decreasing cost function cu (r). Our goal is to find a cover with minimum total cost Σu cu (ru).The multi-radius cover problem is NP-hard as it generalizes the well-known vertex cover problem. In this paper we present a 2-approximation algorithm for it.
The impact and implications of the growth in residential user-to-user traffic
Authors: Kenjiro Cho, Kensuke Fukuda, Hiroshi Esaki, Akira Kato
Venue: Proceedings of the 2006 conference on Applications, technologies, architectures, and protocols for computer communications (2006)

It has been reported worldwide that peer-to-peer traffic is taking up a significant portion of backbone networks. In particular, it is prominent in Japan because of the high penetration rate of fiber-based broadband access. In this paper, we first report aggregated traffic measurements collected over 21 months from seven ISPs covering 42% of the Japanese backbone traffic. The backbone is dominated by symmetric residential traffic which increased 37%in 2005. We further investigate residential per-customer trafficc in one of the ISPs by comparing DSL and fiber users, heavy-hitters and normal users, and geographic traffic matrices. The results reveal that a small segment of users dictate the overall behavior; 4% of heavy-hitters account for 75% of the inbound volume, and the fiber users account for 86%of the inbound volume. About 63%of the total residential volume is user-to-user traffic. The dominant applications exhibit poor locality and communicate with a wide range and number of peers. The distribution of heavy-hitters is heavy-tailed without a clear boundary between heavy-hitters and normal users, which suggests that users start playing with peer-to-peer applications, become heavy-hitters, and eventually shift from DSL to fiber. We provide conclusive empirical evidence from a large and diverse set of commercial backbone data that the emergence of new attractive applications has drastically affected traffic usage and capacity engineering requirements.
Mean value analysis for polling systems in heavy traffic
Authors: R. D. van der Mei, E. M. M. Winands
Venue: Proceedings of the 1st international conference on Performance evaluation methodolgies and tools (2006)

In this paper we present a new approach to derive heavy-traffic asymptotics for polling models. We consider the classical cyclic polling model with exhaustive service at each queue, and with general service-time and switch-over time distributions, and study its behavior when the load tends to one. For this model, we explore the recently proposed mean value analysis (MVA), which takes a new view on the dynamics of the system, and use this view to provide an alternative way to derive closed-from expressions for the expected asymptotic delay; the expressions were derived earlier in [31], but in a different way. Moreover, the MVA-based approach enables us to derive closed-form expressions for the heavy-traffic limits of the covariances between the successive visit periods, which are key performance metrics in many application areas. These results, which have not been obtained before, reveal a number of insensitivity properties of the covariances with respect to the system parameters under heavy-traffic assumptions, and moreover, lead to simple approximations for the covariances between the successive visit times for stable systems. Numerical examples demonstrate that the approximations are accurate when the load is close enough to one.
Combining optimization and simulation in supply chain models
Authors: Andy Siprelle, Mike Denzien
Venue: Proceedings of the 36th conference on Winter simulation (2004)

This case study presents how we have combined simulation with optimization to address problems in supply chain design. This case study illustrates the feasibility and benefits of combining optimization with simulaiton. We also present applications which employ dynamic programming and other mathematical programming techniques to determine where to place inventory in the supply chain.
Visualisation improves the usability of voice-operated mobile phone services
Authors: Mark Howell, Steve Love, Mark Turner
Venue: International Journal of Human-Computer Studies (2006)

Three different versions of a voice-operated mobile city guide service with a hierarchically structured dialogue were evaluated in a mobile setting. One numbered menu style (standard) service, and two services which contained terms derived from underlying real-world referents, were implemented. The real-world referents (metaphors) used were: an office filing system and a computer desktop. It was hypothesized that the use of interface metaphors would allow more participants to visualize the service structure, leading to an improvement in performance relative to the standard service. Forty-two phone users undertook three different tasks with one of the three phone services. User performance and attitudes to the services were recorded, and post-task interviews were conducted. Results showed that significantly more participants using the metaphor-based services visualized the services. Visualizers performed significantly better than non-visualizers, with visualization emerging as a significant predictor of both attitude and performance. We argue that designing speech-based mobile phone services using an appropriate spatial metaphor leads to high levels of visualisation, which allows participants to orient themselves and to navigate more effectively within the hierarchical service architecture. The usability benefits afforded by visualization may become especially important when using phone services in cognitively demanding mobile settings.
Estimating the effects of stress during operational conditions
Authors: Jon French, Jeff Miller
Venue: Proceedings of the 37th conference on Winter simulation (2005)

The Physiological Stress Index (PSI) was developed to provide a rational means for estimating the physiological and behavioral impact of exposure to physical stressors, in this case extreme temperatures and fatigue related to insufficient sleep. Stress can be life threatening and certainly threatens mission effectiveness. It is often derived from combinations of sources such as overheating and lack of sleep, particularly on individuals involved in physically demanding activities such as shipboard firefighting. The PSI was used as a performance modifying adjunct to existing discrete event simulation models designed to estimate shipboard manning requirements given various operational scenarios. Additionally, the PSI was used to estimate the most effective work rest cycles and recovery time required before selected crewmembers could be returned to duties involving significant levels of physical exertion.
Give learners questions to answer while watching animated examples
Authors: Brian D. Gane, Richard Catrambone
Venue: Proceedings of the 7th international conference on Learning sciences (2006)

Participants (N = 93) watched animated examples of a computer algorithm. Participants had either a small set of examples (6) to watch or a larger set of examples (21) from which they could choose which examples to watch. Additionally, participants either watched the animations before answering questions or had questions to answer while watching animations. Participants scored highest when they had questions with the animations; giving these participants a choice amongst multiple examples also reduced learning time.
Shift invariant wavelet packet bases
Authors: I. Cohen, S. Raz, D. Malah
Venue: Proceedings of the Acoustics, Speech, and Signal Processing, 1995. on International Conference - Volume 02 (1995)

A shifted wavelet packet (SWP) library, containing all the time shifted wavelet packet bases, is defined. A corresponding shift-invariant wavelet packet decomposition (SIWPD) search algorithm for a "best basis" is introduced. The search algorithm is representable by a binary tree, in which a node symbolizes an appropriate subspace of the original signal. We prove that the resultant "best basis" is orthonormal and the associated expansion, characterized by the lowest "information cost", is shift-invariant. The shift-invariance stems from an additional degree of freedom, generated at the decomposition stage, and incorporated into the search algorithm. We prove that for any subspace it suffices to consider one of two alternative decompositions, made feasible by the SWP library. The computational complexity of SIWPD may be controlled at the expense of the attained information cost, to an extent of O(2Nlog/sub 2/N).
Coordinated Multilevel Buffer Cache Management with Consistent Access Locality Quantification
Authors: Song Jiang, Kei Davis, Xiaodong Zhang
Venue: IEEE Transactions on Computers (2007)

This paper proposes a protocol for effective coordinated buffer cache management in a multilevel cache hierarchy typical of a client/server system. Currently, such cache hierarchies are managed suboptimally—decisions about block placement and replacement are made locally at each level of the hierarchy without coordination between levels. Though straightforward, this approach has several weaknesses: 1) Blocks may be redundantly cached, reducing the effective total cache size, 2) weakened locality at lower-level caches makes recency-based replacement algorithms such as LRU less effective, and 3) high-level caches cannot effectively identify blocks with strong locality and may place them in low-level caches. The fundamental reason for these weaknesses is that the locality information embedded in the streams of access requests from clients is not consistently analyzed and exploited, resulting in globally nonsystematic, and therefore suboptimal, placement and replacement of cached blocks across the hierarchy. To address this problem, we propose a coordinated multilevel cache management protocol based on consistent access-locality quantification. In this protocol, locality is dynamically quantified at the client level to direct servers to place or replace blocks appropriately at each level of the cache hierarchy. The result is that the block layout in the entirely hierarchy dynamically matches the locality of block accesses. Our simulation experiments on both synthetic and real-life traces show that the protocol effectively ameliorates these caching problems. As anecdotal evidence, our protocol achieves a reduction of block accesses of 11 percent to 71 percent, with an average of 35 percent, over uniLRU, a unified multilevel cache scheme.
Algorithms for solving systems of linear diophantine equations in integer domains
Authors: S. L. Kryvyi
Venue: Cybernetics and Systems Analysis (2006)

Algorithms are described that solve homogeneous systems of linear Diophantine equations over natural numbers and over the set {0, 1}. Properties of the algorithms and their time estimates are given.
A note on determination of oscillation startup condition
Authors: Vimal Singh
Venue: Analog Integrated Circuits and Signal Processing (2006)

There prevails a widespread notion that, given a closed-loop system, oscillation will commence and build up therein if the magnitude of loop gain is greater than unity at the frequency at which the angle of loop gain is zero degree. Three novel examples in which this notion fails are presented.
Extracting Lip Parameters in Speech Synthesis System Driven by Visual-Speech
Authors: Gang Li, Mengjun Wang, Ling Lin
Venue: Proceedings of the First International Conference on Innovative Computing, Information and Control - Volume 2 (2006)

A speech synthesis system is designed for automatically recognizing visual speech generated by the speech impaired and present a new communication approach for the speech-impaired people. In order to acquire more parameters of lip contours, a new model is made up, which can extract the degree of pouting from it. At the same time, the differential coefficients of some parameters are calculated to describe dynamic characteristic of the lip contours. Movement detection and morphological processing are used to extract mouth area and parameters of lip contours from the image sequence.
Analysis of Server Workload and Client Interactions in a News-on-Demand Streaming System
Authors: Frank T. Johnsen, Trude Hafsoe, Carsten Griwodz
Venue: Proceedings of the Eighth IEEE International Symposium on Multimedia (2006)

This paper investigates several aspects of streaming in News-on-Demand services on the Internet by analyzing log files of a news service from Norway's largest online newspaper. We investigate both short and long term effects of client usage of the service. By comparing our results with earlier work, we found that variations in server load depend strongly on local culture. Furthermore, we found that there are slight variations between client usage of the audio and video material.
Performance Monitoring and Visualization of Large-Sized and Multi-Threaded Applications with the Pajé Framework
Authors: Mehdi Kessis, Jean-Marc Vincent
Venue: Proceedings of the International Multi-Conference on Computing in the Global Information Technology (2006)

Performance is a critical issue in the context of massively parallel programs. In practice, it is almost impossible to observe and understand the behavior of such programs without the assistance of automated tools which offer the program developer insights into the execution behavior of complex applications. Most of these tools are based on event-based and tracing techniques. As the size of the parallel system grows, it generates a huge size of events. Visualizing and animating gathered traces often produce a complex and non understandable diagrams and displays. Recently, the Pajé visualization frameworks have been developed in our laboratory ID (Informatique et Distribution). This framework provides interactive and scalable behavioral visualizations of parallel and distributed applications. This papers presents an empirical performance monitoring and visualization study with two large scale applications (JonAS (200.000 LOC1) and Jboss (400.000 LOC)). We have developed an event-based tracing framework for large scale applications monitoring. We use Pajé framework to observe and visualize a large amount of harvested events.
Comparing conceptual designs for mobile access to geo-spatial information
Authors: Peter Fröhlich, Rainer Simon, Lynne Baillie, Hermann Anegg
Venue: Proceedings of the 8th conference on Human-computer interaction with mobile devices and services (2006)

Spatial information appliances (SIA), which enable mobile users to interact with the physical environment, have recently received an increasing amount of interest from the research community. This paper presents a comparative outdoor user study on conceptual designs for 4 interaction areas considered important for SIAs: selection, search, information sniffing, and remote viewing. Implications for future research are discussed.
Precedence-inclusion patterns and relational learning
Authors: Frank J. Oles
Venue: Theoretical Computer Science (2005)

In this paper we introduce precedence-inclusion patterns, which are sets with a strictly partially ordered set of strict partial orders, along with some additional structure. The definition of these structures reflects how multiple partial orders interact in a number of situations such as in text, images, and video. In particular, precedence-inclusion patterns generalize constituent structure trees familiar to computational linguists. Our interest in these objects was initially sparked by their connection with problems of relational learning. We develop the general mathematical theory of precedence-inclusion patterns, we show that each finite set of finite precedence-inclusion relations has a minimal most specific generalization that is unique up to isomorphism, and we explain how this result relates to relational learning.
A low-cost memory remapping scheme for address bus protection
Authors: Lan Gao, Jun Yang, Marek Chrobak, Youtao Zhang, San Nguyen, Hsien-Hsin S. Lee
Venue: Proceedings of the 15th international conference on Parallel architectures and compilation techniques (2006)

The address sequence on the processor-memory bus can reveal abundant information about the control flow of a program. This can lead to critical information leakage such as encryption keys or proprietary algorithms. Addresses can be observed by attaching a hardware device on the bus that passively monitors the bus transaction. Such side-channel attacks should be given rising attention especially in a distributed computing environment, where remote servers running sensitive programs are not within the physical control of the client.Two previously proposed hardware techniques tackled this problem through randomizing address patterns on the bus. One proposal permutes a set of contiguous memory blocks under certain conditions, while the other approach randomly swaps two blocks when necessary. In this paper, we present an anatomy of these attempts and show that they impose great pressure on both the memory and the disk. This leaves them less scalable in high-performance systems where the bandwidth of the bus and memory are critical resources. We propose a lightweight solution to alleviating the pressure without compromising the security strength. The results show that our technique can reduce the memory traffic by a factor of 10 compared with the prior scheme, while keeping almost the same page fault rate as a baseline system with no security protection.
Combining conceptual modeling and active rules for the design of adaptive web applications
Authors: Florian Daniel, Maristella Matera, Giuseppe Pozzi
Venue: Workshop proceedings of the sixth international conference on Web engineering (2006)

In this paper we propose a framework for the design and development of adaptive Web applications. The framework leverages on the integration of two well established approaches: a conceptual model, complemented with a CASE tool for automatic code generation, and a language for expressing ECA rules, supported by an engine for rule execution. Such integration leads to a versatile and flexible adaptivity environment, whose advantage is twofold: on one hand, conceptual modeling and automatic code generation support an efficient development process; on the other hand a detached rule engine allows us to widen the set of adaptivity requirements that can be handled and to overcome some limitations of current modeling approaches.
Resource selection games with unknown number of players
Authors: Itai Ashlagi, Dov Monderer, Moshe Tennenholtz
Venue: Proceedings of the fifth international joint conference on Autonomous agents and multiagent systems (2006)

In the context of pre-Bayesian games we analyze resource selection games with unknown number of players. We prove the existence and uniqueness of a symmetric safety-level equilibrium in such games and show that in a game with strictly increasing linear cost functions every player benefits from the common ignorance about the number of players. In order to perform the analysis we define safety-level equilibrium for pre-Bayesian games, and prove that it exists in a compact-continuous-concave setup; in particular it exists in a finite setup.
Towards the Detection of Breaking News from Online Web Search Keywords
Authors: Tsuyoshi Murata
Venue: Proceedings of the 2006 IEEE/WIC/ACM international conference on Web Intelligence and Intelligent Agent Technology (2006)

People perform keyword search on search engines in order to find information from the Web. Keywords given to search engines can be regarded as the resources for detecting people's information needs. It is often reported that many people perform search intensively after worldwide disasters or accidents. This paper describes a method for detecting breaking news from search keywords that are available online. In our method, real time search keywords are obtained and matched with news words extracted from a news site. Experimental results show that our method has abilities of detecting search keywords related to worldwide news.
List Scheduling Method for Service Oriented Grid Applications
Authors: SungHo Chin, JongHyuk Lee, TaeMyoung Yoon, HeonChang Yu
Venue: Proceedings of the Second International Conference on Semantics, Knowledge, and Grid (2006)

Recently, grid computing environment has being changed to the service-oriented grid integrated with Web Services for supporting more open, scalable and flexible grid architecture. In this architecture, a grid application is the service-oriented grid application in which Grid Services are executed according to the workflow of the grid application. This implies that the grid scheduling method needs to consider grid service characteristics. Although many grid scheduling methods have been developed, we need new grid scheduling method to reflect the service-oriented grid concept and to ensure performance of the grid application. Therefore, we propose the grid service performance model based on factors such as service availability, accessibility, reliability, throughput, and slowdown, and develop grid scheduling method to increase performance of the service-oriented grid application.
Evaluating CSCL log files by social network analysis
Authors: Kari Nurmela, Erno Lehtinen, Tuire Palonen
Venue: Proceedings of the 1999 conference on Computer support for collaborative learning (1999)

In this paper our aim is to present a methodology which can be used in analyzing the interaction processes in a groupware environment. We demonstrate how the social network analysis approach can be used as a method to evaluate the social level structures and processes of a group studying in a CSCL environment. This approach tries to highlight in particular the participatory aspects of collaborative learning processes, but it can also serve as a starting point for more detailed analysis of knowledge building and acquisition processes. The relations between learners and the structure between documents written are the examples studied here.There are some features that make log files especially important in CSCL systems. First, log files can be used automatically, precisely and effectively for data collection. Second, analyzing this information enables evaluative perspective to the collaborative action as a whole. Third, this feedback can be made available immediately for the learning community. As a contribution, we can assume that the network analysis of log files helps us to understand the working processes in CSCL.