ppxscal/embedding_network huggingface dataset:
On the performance of nonparametric specification tests in regression models
Authors: Daniel Miles, Juan Mora
Venue: Computational Statistics Data Analysis (2003)

Some recently developed nonparametric specification tests for regression models are described in a unified way. The common characteristic of these tests is that they are consistent against any alternative hypothesis. The performance of the test statistics is compared by means of Monte Carlo simulations, analysing how heteroskedasticity, number of regressors and bandwidth selection influence the results. The statistics which do not use a bandwidth perform slightly better if the regression model has only one regressor; otherwise, some of the statistics which use a bandwidth behave better if the bandwidth is chosen adequately. These statistics are applied to test the specification of three commonly used Mincer-type wage equations with Uruguayan and Spanish data; all of them are rejected.
Experiences from health information system implementation projects reported in Canada between 1991 and 1997
Authors: Francis Lau, Marilynne Hebert
Venue: Advanced topics in end user computing (2002)

Canada's Health Informatics Association has been hosting annual conferences since the 1970's as a way of bringing information systems professionals, health practitioners, policy makers, researchers, and industry together to share their ideas and experiences in the use of information systems in the health sector. This paper describes our findings on the outcome of information systems implementation projects reported at these conferences in the 1990's. Fifty implementation projects published in the conference proceedings were reviewed, and the authors or designates of 24 of these projects were interviewed. The overall experiences, which are consistent with existing implementation literature, suggest the need for organizational commitment; resource support and training; managing project, change process, and communication; organizational/user involvement and teams approach; system capability; information quality; and demonstrable positive consequences from computerization.
An efficient deterministic parallel algorithm for two processors precedence constraint scheduling
Authors: Hermann Jung, Maria Serna, Paul Spirakis
Venue: Theoretical Computer Science (2003)

We present here a new deterministic parallel algorithm for the two-processor scheduling problem. The algorithm uses only O(n3) processors and takes O(log2n) time on a CREW PRAM. In order to prove the above bounds we show how to compute in NC the lexicographically first matching for a special kind of convex bipartite graphs.
Complete inference systems for weak bisimulation equivalences in the π-calculus
Authors: Huimin Lin
Venue: Information and Computation (2003)

Proof systems for weak bisimulation equivalences in the π-calculus are presented, and their soundness and completeness are shown. Two versions of π-calculus are investigated, one without and the other with the mismatch operator. For each version of the calculus proof systems for both late and early weak bisimulation equivalences are studied. Thus there are four proof systems in all. These inference systems are related in a natural way: the inference system for early equivalence is obtained from the one for late equivalence by replacing the inference rule for input prefix, while the inference system for the version of π-calculus with mismatch is obtained by adding a single inference rule for mismatch to the one for the version without it. The proofs of the completeness results rely on the notion of symbolic bisimulation.
A Parallel Fictitious Domain Method for the Three-Dimensional Helmholtz Equation
Authors: Erkki Heikkola, Tuomo Rossi, Jari Toivanen
Venue: SIAM Journal on Scientific Computing (2002)

The application of a fictitious domain (domain embedding) method to the three-dimensional Helmholtz equation with absorbing boundary conditions is considered. The finite element discretization is performed by using locally fitted meshes, and an algebraic fictitious domain method with a separable preconditioner is used in the iterative solution of the resultant linear systems. Such a method is based on embedding the original domain into a larger one with a simple geometry. With this approach, it is possible to realize the GMRES iterations in a low-dimensional subspace and use the partial solution method to solve the linear systems with the preconditioner. An efficient parallel implementation of the iterative algorithm is introduced. Results of numerical experiments demonstrate good scalability properties on distributed-memory parallel computers and the ability to solve high frequency acoustic scattering problems.
GridG: generating realistic computational grids
Authors: Dong Lu, Peter A. Dinda
Venue: ACM SIGMETRICS Performance Evaluation Review (2003)

A realistic workload is essential in evaluating middleware for computational grids. One important component of that workload is the raw grid itself: an annotated graph representing the network topology and the hardware and software available on each node and link within it. GridG is an extensible synthetic generator of such graphs that is implemented as a series of transformations on a common graph format. The paper provides a definition of and requirements for grid generation. We then describe the GridG process in two steps: topology generation and annotation. For topology generation, we have both a model and a mechanism. We leverage Tiers, an existing tool commonly used in the networking community, but we extend it to produce graphs that conform to recently discovered power laws of Internet topology. We also contribute to the theory of network topology by pointing out a contradiction between two laws, and proposing a new version of one of them. For annotation, we have developed a mechanism, the requirements for a model, and identified the open problem of characterizing the distribution and correlation of hardware and software resources on the network.
Technological Innovation in the Pharmaceutical Industry: The Use of Organizational Control in Managing Research and Development
Authors: Laura B. Cardinal
Venue: Organization Science (2001)

The literature on the management of R&D professionals strongly advocates managing R&D projects on a project-by-project basis. This literature suggests that projects should be managed differently depending upon project characteristics such as risk, ambiguity, and nonroutineness. While the primary emphasis of the R&D professional literature has been on project teams, the purpose of this study is to examine the impact of organization-wide controls on innovativeness at the firm level.In a sample of 57 pharmaceutical firms, this study investigates the influence of organizational controls on the research and development activities of R&D professionals. This study is one of a handful of studies that simultaneously explores the use of input, behavior, and output controls. Two categories of innovation are considered as dependent variables: incremental innovations in the form of drug enhancements and radical innovations in the form of new drugs. Contrary to existing theory and hypotheses developed in this study, the results show that input, behavior, and output control enhanced radical innovation, and input and output controls enhanced incremental innovation.These results challenge several important features of existing models of R&D management and diverge from common beliefs about R&D management at the project level. While it is commonly accepted that incremental and radical innovation should be managed differently, the results of this study suggest otherwise. In this instance, the management of R&D activities may be considered more similar than previously thought.
Book Reviews
Authors: Benjamin Lev, Hanif D. Sherali, Antanas Zilinskas, Stefan Voss, Arnold Reisman
Venue: Interfaces (2000)

The range of books reviewed is wide, covering theory and applications in operations research, statistics, management science, econometrics, mathematics, computers, and information systems (no software is reviewed). In addition, we include books in other fields that emphasize technical applications. Publishers who wish to have their books reviewed should send them to Professor Benjamin Lev. We list the books received; not all books received can be reviewed because space and time are limited. Those who would like to review books are urged to send me their names, addresses, and specific areas of expertise. We commission all reviews and do not accept unsolicited book reviews. Readers are encouraged to suggest books that might be reviewed or to ask publishers to send me copies of such books.
Finite difference, finite element and finite volume methods applied to two-point boundary value problems
Authors: Qing Fang, Takuya Tsuchiya, Tetsuro Yamamoto
Venue: Journal of Computational and Applied Mathematics (2002)

This paper considers the finite difference, finite element and finite volume methods applied to the two-point boundary value problem -d/dx(p(x) du/dx) = f(x), a < x < b, u(a) = u(b) = 0. By using an inversion formula of a nonsingular tridiagonal matrix, explicit expressions of approximate solutions by three methods are given, which lead to a unified understanding of these methods as well as their unified error estimates. Numerical examples are also given.
Semi-Online Maintenance of Geometric Optima and Measures
Authors: Timothy M. Chan
Venue: SIAM Journal on Computing (2003)

We give the first nontrivial worst-case results for dynamic versions of various basic geometric optimization and measure problems under the semi-online model, where during the insertion of an object we are told when the object is to be deleted. Problems that we can solve with sublinear update time include the Hausdorff distance of two point sets, discrete 1-center, largest empty circle, convex hull volume in three dimensions, volume of the union of axis-parallel cubes, and minimum enclosing rectangle. The decision versions of the Hausdorff distance and discrete 1-center problems can be solved fully dynamically. Some applications are mentioned.
The typical spectral shape of an economic variable
Authors: C. W. J. Granger
Venue: Essays in econometrics: Spectral analysis, seasonality, nonlinearity, methodology, and forecasting (2001)

In recent years, a number of power spectra have been estimated from economic data and the majority have been found to be of a similar shape. A number of implications of this shape are discussed, particular attention being paid to the reality of business cycles, stability and control problems, and model building.
An expert system for multiobjective decision making: application of fuzzy linguistic preferences and goal programming
Authors: M. H. Rasmy, Sang M. Lee, W. F. Abd El-Wahed, Ali M. Ragab, M. M. El-Sherbiny
Venue: Fuzzy Sets and Systems (2002)

This paper introduces an interactive approach for solving multiobjective decision making (MODM) problems based on linguistic preferences and architecture of a fuzzy expert system. The aim of this paper is to consider the decision maker's (DMs) preferences in determining the priorities and aspiration levels, in addition to analysis of conflict among the goals. The main concept presented in this paper is to convert the MODM problem into its equivalent goal programming (GP) problem by appropriately setting the priority and aspiration level for each objective. The conversion approach introduced is based on fuzzy linguistic preferences of DM, in addition to the concepts of conflict analysis among objective functions and fuzzy set theory.
Power-aware virtual base stations for wireless mobile ad hoc communications
Authors: Ahmed Safwat, Hossam Hassanein, Hussein Mouftah
Venue: Computer Networks: The International Journal of Computer and Telecommunications Networking (2003)

In this paper, we propose a novel infrastructure formation scheme for wireless mobile ad hoc networks. The proposed architecture, namely, power-aware virtual base stations (PA-VBS), mimics and maintains the operation of the conventional fixed infrastructure in cellular networks. In the PA-VBS protocol, a mobile node is elected from a set of nominees to act as a temporary base station within its zone based on its residual battery capacity. We study the characteristics and performance of PA-VBS by means of simulation. It is shown that PA-VBS scales well to large networks of mobile stations, and that it outperforms other infrastructure-formation protocols in terms of load balancing. The PA-VBS architecture facilitates the development of a comprehensive and promising framework for quality of service (QoS) management in wireless mobile ad hoc networks once the proper integration of the MAC protocol with the routing and call admission control mechanisms is established. Moreover, it lays the groundwork for assigning bandwidth, and/or implementing priorities, and hence for QoS-based routing by conveying the quality of a path prior to call setup. To the authors' best knowledge, this is the first time that energy is used as a basis for developing a wireless mobile infrastructure, and achieving load balancing.
A Fast, Two-Dimensional Panel Method
Authors: Prabhu Ramachandran, S. C. Rajan, M. Ramakrishna
Venue: SIAM Journal on Scientific Computing (2002)

A new two-dimensional panel technique has been developed to solve Laplacian flows, which eliminates the edge effect present in traditional panel methods. Such a method is very useful for applications where the velocity induced by the panels is required at arbitrary locations. Particle based flow solvers are a prime example. The method, however, requires considerably more computational effort. In this paper the method is modified to improve computational efficiency by adapting the fast multipole algorithm for the panel method. Significant improvement in computational efficiency is obtained while ensuring that the edge effects are eliminated.
What's hot and what's not: tracking most frequent items dynamically
Authors: Graham Cormode, S. Muthukrishnan
Venue: Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2003)

Most database management systems maintain statistics on the underlying relation. One of the important statistics is that of the "hot items" in the relation: those that appear many times (most frequently, or more than some threshold). For example, end-biased histograms keep the hot items as part of the histogram and are used in selectivity estimation. Hot items are used as simple outliers in data mining, and in anomaly detection in networking applications.We present a new algorithm for dynamically determining the hot items at any time in the relation that is undergoing deletion operations as well as inserts. Our algorithm maintains a small space data structure that monitors the transactions on the relation, and when required, quickly outputs all hot items, without rescanning the relation in the database. With user-specified probability, it is able to report all hot items. Our algorithm relies on the idea of "group testing", is simple to implement, and has provable quality, space and time guarantees. Previously known algorithms for this problem that make similar quality and performance guarantees can not handle deletions, and those that handle deletions can not make similar guarantees without rescanning the database. Our experiments with real and synthetic data shows that our algorithm is remarkably accurate in dynamically tracking the hot items independent of the rate of insertions and deletions.
Stochastic pyramid revisited
Authors: J. M. Jolion
Venue: Pattern Recognition Letters (2003)

We focus in this paper on a new model for graph decimation which is based on the stochastic pyramid algorithm. In this study, we present some trends towards a better understanding of the new properties arising from the removal of the sequentiality constraint of this so-called technique.
Automated test case generation for the stress testing of multimedia systems
Authors: Jian Zhang, S. C. Cheung
Venue: Software&mdash;Practice Experience (2002)

With the advancement in network bandwidth and computing power, multimedia systems have become a popular means for information delivery. However, general principles of system testing cannot be directly applied to testing of multimedia systems on account of their stringent temporal and synchronization requirements. In particular, few studies have been made on the stress testing of multimedia systems with respect to their temporal requirements under resource saturation. Stress testing is important because erroneous behavior is most likely to occur under resource saturation. This paper presents an automatable method of test case generation for the stress testing of multimedia systems. It adapts constraint solving techniques to generate test cases that lead to potential resource saturation in a multimedia system. Coverage of the test cases is defined upon the reachability graph of a multimedia system. The proposed stress testing technique is supported by tools and has been successfully applied to a real-life commercial multimedia system. Although our technique focuses on the stress testing of multimedia systems, the underlying issues and concepts are applicable to other types of real-time systems.
A Note on An Axiomatization of the Core of Market Games
Authors: Peter Sudhölter, Bezalel Peleg
Venue: Mathematics of Operations Research (2002)

As shown by Peleg (1993), the core of market games is characterized by nonemptiness, individual rationality, superadditivity, the weak reduced game property, the converse reduced game property, and weak symmetry. It was not known whether weak symmetry was logically independent. With the help of a certain transitive 4-person TU game, it is shown that weak symmetry is redundant in this result. Hence, the core on market games is axiomatized by the remaining five properties, if the universe of players contains at least four members.
Effective Computer Technology for Data Processing
Authors: O. D. Zhukov, Naphtali Rishe
Venue: Proceedings of the 1997 International Conference on Parallel and Distributed Systems (1997)

In this paper the possibility of creating an effective computer algebra on the basis of special polynomial conversions within GF(p**e) and mixed number systems is considered.It is shown that this technique are defined by the transforming which maps the problem of multiplication or addition of two polynomials onto a completely parallel scheme where the mapped polynomial coefficients are multiplied or added pairwise. Thus, it allows to obtain a product of two degree 'n' polynomials using 'n' multiplications instead of n**2 (without summations!).In the case of multiplication of two complex numbers a number of operations is reduced to two real multiplications instead of four (without summations).The modified GF(p**e), are defined over irreducible polynomials, R(x), of order e, and elements in GF(x**e) are computed as PP's, mod R(x) over GF(p). If, instead,the GF(x**e) multiplication is performed mod Q(x), where Q(x) is factorizable and of a suitably high degree, the Polynomial Ring Mapping (PRM) decomposition can be used.A final reduction, mod R(x), realizes the GF(p**e) product. By appropriate choice of PRM and R(x), all operations occure over GF(p), and reduction by an irregular polynomial modulus is eliminated. Solutions for large m and small p are possible using multidimensional PRM technique. The three conventional methods to perform GF(p**e) multiplication use standard basis, normal basis, or dual basis scheme of multiplication but all three methods require at least more than e**2 general multiplications, mod p.In contrary, polynomial products (PP's) can be decomposed by the PRM into a small number of autonomous products, mod p, performed in parallel. Of course, an effect of using the represented technique will be high if density of the described procedures relatively a general volume of computations is enough large. In this case a rate of data processing can exceed a rate got by usual tools more than one order.Techniques described in this paper can be used in media of parallel systems. It is well-known that GF(p**e) data processing is required in number of enough important applications, for example, cyclic convolutions as well as erro-correction, cryptographic, and multivalued logic systems. A further development of the represented methods can essentally extend a field of such applications.The PRM-based modified GF(p**e) system could be realized on the basis of the introduced modified binary number system BMA.The BMA could provide the rate of number processing comparable with other approaches requesting special computers.
The Bounded Cycle-Cover Problem
Authors: Dorit S. Hochbaum, Eli V. Olinick
Venue: INFORMS Journal on Computing (2001)

We consider the bounded cycle-cover problem, which is to find a minimum cost cycle cover of a two-connected graph such that no cycle in the cover contains more than a prescribed numbered of edges. This problem arises in the design of fiber-optic telecommunications networks that employ multiple self-healing rings to provide routing for communication traffic, even in the event of a fiber cut or other type of link failure. We present this problem, along with several related problems, and develop heuristic algorithms that find near optimal solutions for the bounded cycle-cover problem based on solution techniques for these related problems. Empirical results of these algorithms, applied to randomly generated problem instances, are presented and discussed.
A method for isolating morphological effects on evolved behaviour
Authors: Josh C. Bongard, Rolf Pfeifer
Venue: Proceedings of the seventh international conference on simulation of adaptive behavior on From animals to animats (2002)

As the field of embodied cognitive science begins to mature, it is imperative to develop methods for identifying and quantifying the constraints and opportunities an agent's body places on its possible behaviours. In this paper we present results from a set of experiments conducted on 10 different legged agents, in which we evolve neural controllers for locomotion. The genetic algorithm and neural network architecture were kept constant across the agent set, but the agents had different sizes, masses and body plans. It was found that increased mass has a negative effect on the evolution of locomotion, but that this does not hold for all of the agents tested. Also, the number of legs has an effect on evolved behaviours, with hexapedal agents being the easiest for which to evolve locomotion, and wormlike agents being the most difficult. Moreover, it was found that repeating the experiments with a larger neural network increased the evolutionary potential of some of the agents, but not for all of them. The results suggest that by employing this methodology we can test hypotheses about the behavioural effect of specific morphological features, which has to date eluded precise quantitative analysis.
On discrete preference structures
Authors: Bernard De Baets, János Fodor
Venue: Technologies for constructing intelligent systems: Tasks (2002)

In this paper, we introduce and study discrete preference structures. Such structures are expressed on finite chains and arise in the context of ordinal or linguistic preference modelling. Two classes of discrete preference structures are identified and characterized.
Understanding and enhancing call centre computer-
Authors: Anette Steel
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

There are many interactions that take place at a call centre; between the customer and agent, the agent and computer, and indirectly between the customer and computer. This paper proposes areas of research, eg auditory feedback and human-human communication, which could provide insight and possible improvement to the interaction. The paper also describes studies that have been carried out, as well as studies that are being planned.