ppxscal/embedding_network huggingface dataset:
Highly accurate verified error bounds for Krylov type linear system solvers
Authors: Axel Facius
Venue: Applied Numerical Mathematics (2003)

Preconditioned Krylov subspace solvers are an important and frequently used technique for solving large sparse linear systems. There are many advantageous properties concerning convergence rates and error estimates. However, implementing such a solver on a computer, we often observe an unexpected and even contrary behavior.The purpose of this paper is to show that this gap between the theoretical and practical behavior can be narrowed by using a problem-oriented arithmetic. In addition we give rigorous error bounds to our computed results.
ObjectGlobe: Ubiquitous query processing on the Internet
Authors: R. Braumandl, M. Keidl, A. Kemper, D. Kossmann, A. Kreutz, S. Seltzsam, K. Stocker
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (2001)

We present the design of ObjectGlobe, a distributed and open query processor for Internet data sources. Today, data is published on the Internet via Web servers which have, if at all, very localized query processing capabilities. The goal of the ObjectGlobe project is to establish an open marketplace in which data and query processing capabilities can be distributed and used by any kind of Internet application. Furthermore, ObjectGlobe integrates cycle providers (i.e., machines) which carry out query processing operators. The overall picture is to make it possible to execute a query with &ndash; in principle &ndash; unrelated query operators, cycle providers, and data sources. Such an infrastructure can serve as enabling technology for scalable e-commerce applications, e.g., B2B and B2C market places, to be able to integrate data and data processing operations of a large number of participants. One of the main challenges in the design of such an open system is to ensure privacy and security. We discuss the ObjectGlobe security requirements, show how basic components such as the optimizer and runtime system need to be extended, and present the results of performance experiments that assess the additional cost for secure distributed query processing. Another challenge is quality of service management so that users can constrain the costs and running times of their queries.
Transformation of SDL specifications for system-level timing analysis
Authors: Marek Jersak, Kai Richter, Rafik Henia, Rolf Ernst, Frank Slomka
Venue: Proceedings of the tenth international symposium on Hardware/software codesign (2002)

Complex embedded systems are typically specified using multiple domain-specific languages. After code-generation, the implementation is simulated and tested. Validation of non-functional properties, in particular timing, remains a problem because full test coverage cannot be achieved for realistic designs. The alternative, formal timing analysis, requires a system representation based on key application and architecture properties. These properties must first be extracted from a system specification to enable analysis. In this paper we present a suitable transformation of SDL specifications for system-level timing analysis. We show ways to vary modeling accuracy in order to apply available formal techniques. A practical approach utilizing a recently developed system model is presented.
Congestion minimization during placement without estimation
Authors: Bo Hu, Malgorzata Marek-Sadowska
Venue: Proceedings of the 2002 IEEE/ACM international conference on Computer-aided design (2002)

This paper presents a new congestion minimization technique for standard cell global placement. The most distinct feature of this approach is that it does not follow the traditional "estimate-then-eliminate" strategy. Instead, it avoids the excessive usage of routing resources by the "local" nets so that more routing resources are available for the uncertain "global" nets. The experimental results show that our new technique, SPARSE, achieves better routability than the traditional total wire length (Bounding Box) guided placers, which had been shown to deliver the best routability results among the placers optimizing different cost functions [2]. Another feature of SPARSE is the capability of allocating white space implicitly. SPARSE exploits the well known empirical Rent's rule and is able to improve the routability even more in the presence of white space. Compared to the most recent academic routability-driven placer Dragon[8], SPARSE is able to produce solutions with equal or better routability.
Sensitivity Analysis of Insurance Risk Models Via Simulation
Authors: Søren Asmussen, Reuven Y. Rubinstein
Venue: Management Science (1999)

We show how, from a single simulation run, to estimate the ruin probabilities and their sensitivities (derivatives) in a classic insurance risk model under various distributions of the number of claims and the claim size. Similar analysis is given for the tail probabilities of the accumulated claims during a fixed period. We perform sensitivity analysis with respect to both distributional and structural parameters of the underlying risk model. In the former case, we use the score function method and in the latter, a combination of the push-out method and the score function. We finally show how, from the same sample path, to derive a consistent estimator of the optimal solution in an optimization problem associated with excess-of-loss reinsurance.
Impacts of net-generation attributes, seductive properties of the internet, and gratifications-obtained on internet use
Authors: Louis Leung
Venue: Telematics and Informatics (2003)

The Net-generation is a new generation who was born between 1977 and 1997. But unlike their parents, they are not defined by demographics alone, but rather by a combination of their demographic cohort, values, life experiences, and behavior. Based on the assumption that the Net-geners will exhibit differences from the boomers, the purpose of this study is to (1) identify attributes that can distinctly characterize the Net-generation and (2) examine how these attributes, together with perceived seductive properties of the Internet (e.g., pleasure of control and fluidity of identity) and gratifications-obtained from Internet use can predict Net-geners' popular Internet activities. Using a probability sample, a telephone survey was conducted with 976 respondents in the age of 16-24. Exploratory factor analysis found that Net-geners are (1) strongly principled and believe in fundamental rights to information, (2) emotionally open on the Net, (3) innovative and investigative, and (4) independent, confident, and preoccupied with maturity. Results of hierarchical regression analysis show that Net-geners are emotionally open individuals who use the Internet primarily as a social technology. Heavy users of the Internet were motivated by the ability through the Internet to show affections, to establish social bonds, and to escape. Most important, heavy users of the Internet often enjoyed the illusory power of being able to control the world inside the computer when playing online games and attracted by the ability of the Internet to offer companionship in the virtual world. Furthermore, Net-geners were fascinated by the capacity of the Internet to allow them to present a different persona when interacting online such as chatting on ICQ. This "fluidity of identity" gives Net-geners a feeling of status and modernity, which may bolster their self-esteem.
Best possible componentwise parameter inclusions computable from a priori estimates, measurements, and bounds for the measurement errors
Authors: G. Heindl
Venue: Journal of Computational and Applied Mathematics (2003)

We consider problems of parameter estimation which can be described as follows: The available information about the parameter x ∈ Rn to be estimated is x ∈ f-1(Y) ∩ X0, where f:D → Rm, D ⊂ Rn, is a given two times continuously differentiable mapping, Y a given box in Rm, and X0 a given box in D.Then the best possible componentwise inclusion of x is the smallest box X ⊆ X0 containing f-1(Y) ∩ X0. Therefore we try to compute boxes X(i), X(o) sufficiently close to X and such that X(i) ⊂ X ⊂ X(o).It will be shown that this can be done under conditions usually fulfilled in practice. Then the problem can be reduced to the solvable problem to compute inner and outer approximations of the interval hull of a given tolerance polyhedron.As a typical practical case, a problem of deriving best inclusions of coordinates of points from a priori estimates, distance measurements, and bounds for the measurement errors is considered.Computed solutions for some illustrating numerical examples are presented.
Integrated Simulation, Heuristic and Optimisation Approaches to Staff Scheduling
Authors: Andrew J. Mason, David M. Ryan, David M. Panton
Venue: Operations Research (1998)

This paper details a new simulation and optimisation based system for personnel scheduling (rostering) of customs staff at the Auckland International Airport, New Zealand. An integrated approach using simulation, heuristic descent, and integer programming techniques has been developed to determine near-optimal staffing levels. The system begins by using a new simulation system embedded within a heuristic search to determine minimum staffing levels for arrival and departure work areas. These staffing r equirements are then used as the input to an integer programming model, which optimally allocates full- and part-time staff to each period of the working day. These shifts are then assigned to daily work schedules having a six-day-on, three-day-off structure. The application of these techniques has resulted in significantly lower staffing levels, while at the same time creating both high-quality rosters and ensuring that all passenger processing targets are met. This paper charts the development of this system, outlines failures where they have occurred, and summarises the ongoing impacts of this work on the organisation.
A Method to Design a Hierarchical Network of Field Pipelines by Solving a Sequence of Extremal Problems
Authors: O. A. Babich, O. Yu. Pershin, A. V. Mushtonin
Venue: Automation and Remote Control (2003)

Consideration was given to the problem of optimal design of the field pipeline network for oil collection and transportation. The object was described; the problem was formulated; and the formulations of extremal problems were presented. A numerical method of solution was proposed on the basis of the universal procedure of determining the spanning trees of the edge-weighted graph arranged in the nondecreasing order of their lengths. The method was illustrated by a numerical example.
Topological Design of Two-Level Telecommunication Networks with Modular Switches
Authors: Steven Chamberland, Brunilde Sansò, Odile Marcotte
Venue: Operations Research (2000)

In this article we propose a mixed 0-1 linear programming model for the topological network design problem with modular switches such as the ones that will be used in asynchronous transfer mode (ATM) frame relay and other broadband networks. The model includes the location of switches, their configuration with respect to ports and multiplexers, the design of an access network with a star topology, and a backbone network with a fixed topology (ring or tree). To obtain a solution, we propose a greedy heuristic that provides a good starting solution, and a tabu search heuristic to improve the solution. Finally, we present an example of the application of the heuristics and results for a set of randomly generated problems with up to 500 users and 30 potential switch sites. For the hundreds of problems generated, the tabu algorithm produced solutions that were, on average, within 1.5% of the optimal solution, and in the worst case within 4.95% of the optimal solution.
Moments of infinite convolutions of symmetric Bernoulli distributions
Authors: C. Escribano, M. A. Sastre, E. Torrano
Venue: Journal of Computational and Applied Mathematics (2003)

We study the infinite convolution of symmetric Bernoulli distributions associated to a parameter r. We obtain an explicit formula for the moments as a function of Bernoulli numbers and conditioned partitions. Applying this formula we obtain the moments as a quotient of polynomials in the parameter r. The leading coefficient of the numerator is related to the asymptotic behavior of the moments and, unexpectedly, this coefficients are the absolute values of Euler numbers.
Coevolution of Firm Absorptive Capacity and Knowledge Environment: Organizational Forms and Combinative Capabilities
Authors: Frans A. J. Van Den Bosch, Henk W. Volberda, Michiel De Boer
Venue: Organization Science (1999)

This paper advances the understanding of absorptive capacity for assimilating new knowledge as a mediating variable of organization adaptation. Many scholars suggest a firm's absorptive capacity plays a key role in the process of coevolution (Lewin et al., this issue). So far, most publications, in following Cohen and Levinthal (1990), have considered the level of prior related knowledge as the determinant of absorptive capacity. We suggest, however, that two specific organizational determinants of absorptive capacity should also be considered: organization forms and combinative capabilities. We will show how these organizational determinants influence the level of absorptive capacity, ceteris paribus the level of prior related knowledge. Subsequently, we will develop a framework in which absorptive capacity is related to both micro- and macrocoevolutionary effects. This framework offers an explanation of how knowledge environments coevolve with the emergence of organization forms and combinative capabilities that are suitable for absorbing knowledge. We will illustrate the framework by discussing two longitudinal case studies of traditional publishing firms moving into the turbulent knowledge environment of an emerging multimedia industrial complex.
Likelihood-based inference for asymmetric stochastic volatility models
Authors: F. Bartolucci, G. De Luca
Venue: Computational Statistics Data Analysis (2003)

A likelihood approach for fitting asymmetric stochastic volatility models is proposed. It is first shown that, using a quadrature method, the likelihood of these models may be approximated, with the required level of accuracy, by a function that may be easily evaluated using matrix calculus along with its first and second derivatives. The approximated likelihood may be maximized using a standard Newton-Raphson algorithm, and confidence intervals for the parameters may be computed. Moreover, the hypothesis of an asymmetric response of volatility to shocks in the series may be simply tested. Before applying the procedure to real data, a simulation study investigates the reliability of the parameter estimates.
Modeling Stream-Based Applications Using the SBF Model of Computation
Authors: Bart Kienhuis, Ed F. Deprettere
Venue: Journal of VLSI Signal Processing Systems (2003)

Modeling applications and architectures at various levels of abstraction is becoming more and more an accepted approach in embedded system design. When looking at the modeling of applications in the domain of video, audio, and graphics applications, we notice that they exhibit a high degree of task parallelism and operate on streams of data. Models that we can use to specify such stream-based applications on a high level of abstraction are the dataflow models and process network models. Each of these models has its own merits. Therefore, an alternative approach is to introduce a model of computation that combines the semantics of both models of computation. In this article, we introduce such a model of computation, which we call the Stream-Based Functions (SBF) model of computation and show an example. Furthermore, we discuss the composition and decomposition of SBF objects and put the SBF model of computation in the context of relevant dataflow models and process network models.
Alternative Models of Restructured Electricity Systems, Part 1: No Market Power
Authors: Jacqueline Boucher, Yves Smeers
Venue: Operations Research (2001)

Different equilibrium concepts have been proposed by various authors (Schweppe et al., Hogan et al., Chao and Peck, Wu et al.) to analyse competitive electricity systems. We establish correspondences between these different models through a single framework and provide additional interpretations of these equilibrium concepts. This unifying conceptual view also provides a computationally feasible approach to simulate the market. It also opens the way to the modeling of some imperfect markets.
Symbolic Computation of Moments in Priority Queues
Authors: Steve Derkic, James E. Stafford
Venue: INFORMS Journal on Computing (2002)

Analytical tools such as Laplace-Stieltjes transforms and z-transforms are commonly used to characterize queueing-theoretic quantities such as busy-period, waiting-time, and queue-size distributions. Many of these transforms, particularly in M/G/1 priority queueing applications, tend to be cumbersome expressions that involve both implicit and recursive functional relationships. Due to these complications, even the task of deriving moments becomes an algebraically intensive exercise. The focus of this paper is to describe a collection of efficient symbolic procedures useful for automating the tedious mathematical computations one encounters in working with these kinds of transforms. Central to this development is the introduction of a set-partition operator that enables moment expressions for delay cycles to be determined quickly and exactly, without having to derive any sort of higher-order derivative or Taylor-series expansion. Making use of this operator eliminates laborious derivations by hand and permits moments of various priority queueing-related quantities to be easily determined. In particular, the procedures are applied to the classical non-preemptive and preemptive resume queues, as well as two advanced variants of these models.
Teamwork Quality and the Success of Innovative Projects: A Theoretical Concept and Empirical Evidence
Authors: Martin Hoegl, Hans Georg Gemuenden
Venue: Organization Science (2001)

An extensive body of literature indicates the importance of teamwork to the success of innovative projects. This growing awareness, that "good teamwork" increases the success of innovative projects, raises new questions: What is teamwork, and how can it be measured? Why and how is teamwork related to the success of innovative projects? How strong is the relationship between teamwork and various measures of project success such as performance or team member satisfaction? This article develops a comprehensive concept of the collaboration in teams, called Teamwork Quality (TWQ). The six facets of the TWQ construct, i.e., communication, coordination, balance of member contributions, mutual support, effort, and cohesion, are specified. Hypotheses regarding the relationship between TWQ and project success are tested using data from 575 team members, team leaders, and managers of 145 German software teams. The results of the structural equation models estimated show that TWQ (as rated by team members) is significantly associated with team performance as rated by team members, team leaders, and team-external managers. However, the magnitude of the relationship between TWQ and team performance varies by the perspective of the performance rater, i.e., manager vs. team leader vs. team members. Furthermore, TWQ shows a strong association with team members' personal success (i.e., work satisfaction and learning).
An Adaptive User Interface Based On Personalized Learning
Authors: Jiming Liu, Chi Kuen Wong, Ka Keung Hui
Venue: IEEE Intelligent Systems (2003)

In human-computer interaction, user interface events and frequencies can be recorded and organized into episodes. By computing episode frequencies and implication relations, we can automatically derive application-specific episode associations and therefore enable an application interface to adaptively provide just-in-time assistance to a user. The authors identify five issues related to designing an adaptive user interface: interaction tracking, episodes identification, user pattern recognition, user intention prediction, and user profile update. In particular, they demonstrate how to identify episodes and associate them with an interface that can act on a user's behalf to interact with an application based on certain recognized plans. To adapt to different users' needs, the interface can personalize its assistance by learning user profiles. For example, by detecting and analyzing users' behavior patterns in using Microsoft Word, the interface can automatically assist users in several Word tasks. The authors' Word interface provides episode associations at two levels: text-level (phrase association) and paragraph-level (formatting automation). They conducted two pilot experiments to evaluate the interface's performance. The suggestions it provided and its ease of use were well received by users, and the interface can to a certain extent increase the productivity of type-setting.
Flash flood forecast hydrological model
Authors: V. Estupina Borrell, C. Llovel, D. Dartus
Venue: Development and application of computer techniques to environmental studies (2002)

Flash floods are characterized by their violence and the rapidity of their occurrence. Because they don't occur frequently and are so unpredictable their anticipation is still subject to research : when flash floods occur, tools usually used by the Sercice d'Annonce des Crues (SAC : national flood forecast services of France) are not efficient to protect people form this kind of event. Our main goal here is to develop an operational and robust methodology for flash flood forecasting. This methodology should give relevant data about the flood evolution and should be applicable even if historical and observed data are sparse.The flash flood evolution model that we have developed consists in two steps : first, the flood runoff generation in the upstream part of the basin, then it's propagation in the main river. Flash flood generation model (MARINE) is a rainfall - runoff model that only integrates data from space. Classical hydrology equations are resolved with enough hypothesis to allow real time exploitation. The minimum data required by the model are the Digital Elevation Model, used to calculate slopes that generate runoff, the rainfall data from meteorological radar and the soil properties viewed from space and that have hydrological influence (land cover map, main rivers). Flood propagation model resolves Saint Venant equations and simulates flood propagation in main rivers.In this paper, we will insist on the hypotheses we did to simplify hydraulic equations and their resolution in our model to do so we based our analysis on known past events defining how space data can replace observed data in hydrological simulation.This analysis has been tested in a 2D flood propagation model. Results for the Aude flood of November 1999 are very encouraging.
The effect of the order of nonlinear dispersive equation on the compact and noncompact solutions
Authors: Abdul-Majid Wazwaz
Venue: Applied Mathematics and Computation (2003)

The effect of the order of nonlinear dispersive partial differential equation on the compact and noncompact solutions is studied in this paper. Two variants of the KdV equation of odd orders are examined. Our analysis reveals that the physical nature of these nonlinear KdV-type of equations are different. Two distinct sets of general formulas for each type of variants are performed to present a fairly complete understanding of the compact and noncompact structures.