ppxscal/embedding_network huggingface dataset:
Materializing views with minimal size to answer queries
Authors: Rada Chirkova, Chen Li
Venue: Proceedings of the twenty-second ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems (2003)

In this paper we study the following problem. Given a database and a set of queries, we want to find, in advance, a set of views that can compute the answers to the queries, such that the size of the viewset (i.e., the amount of space, in bytes, required to store the viewset) is minimal on the given database. This problem is important for many applications such as distributed databases, data warehousing, and data integration. We explore the decidability and complexity of the problem for workloads of conjunctive queries. We show that results differ significantly depending on whether the workload queries have self-joins. If queries can have self-joins, then a disjunctive viewset can be a better solution than any set of conjunctive views. We show that the problem of finding a minimal-size disjunctive viewset is decidable, and give an upper bound on its complexity. If workload queries cannot have self-joins, there is no need to consider disjunctive viewsets, and we show that the problem is in NP. We describe a very compact search space of conjunctive views, which contains all views in at least one optimal disjunctive viewset. We give a dynamic-programming algorithm for finding minimal-size disjunctive viewsets for queries without self-joins, and discuss heuristics to make the algorithm efficient.
Principles for mujltimodal user inteface desgin
Authors: James A. Larson, Sharon Oviatt
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

The goal of this workshop is to identify ten guiding principles for designing multimodal user interfaces. Researchers will use these principles to identify topics requiring further research. Practitioners will use these principles to generate guidelines for designing multimodal user interfaces.
Propagation of Interval Values in Simple Processing Networks
Authors: Brett W. Schug, Matthew J. Realff
Venue: INFORMS Journal on Computing (1999)

Process network optimization problems are prevalent in the processing industries. Streams of differing compositions undergo mixing and splitting steps to attain product streams of desired properties. Constraint propagation of system variable bounds across a process network allows identification of system capabilities prior to optimization, and expedites solution of the optimization itself. In this article, an improved generalized algorithm for interval propagation in simple networks, and an extension of the model structure of the pooling problem beyond that of simple pools and streams, are presented. An application of preprocessing to a branch-and-bound approach to process network NLP global optimization is given. The importance of model structure to tightness of derived bounds is illustrated. This work demonstrates that knowledge of the problem structure may be used to integrate reasoning and optimization, and that specialized structures and specific domain constraints can lead to customized algorithms that are significantly more efficient than general algorithms.
The virtual corporation and trust: balancing between identity and innovation
Authors: Wendy Jansen, Hans P. M. Jägers, Wilchard Steenbakkers
Venue: Managing virtual web organizations in the 21st century: issues and challenges (2002)

Virtual corporations are seen as new organisational forms to ensure knowledge sharing and innovation. In this chapter the reason for the knowledge-creating competence of virtual corporations is explained. A shared identity and mutual trust of the participants are of paramount importance to innovation. Virtual corporations are in fact balancing on a tightrope. They have to create an identity which is strong enough for the participants to trust each other. At the same time the identity shared by the participants of the virtual corporation must not become so strong that very promising innovative avenues are blocked. ICT will fulfil an important function here which is mainly aimed at the support of the social relation between the participants.
Query processing and optimization in Oracle Rdb
Authors: Gennady Antoshenkov, Mohamed Ziauddin
Venue: The VLDB Journal &mdash; The International Journal on Very Large Data Bases (1996)

This paper contains an overview of the technology used in the query processing and optimization component of Oracle Rdb, a relational database management system originally developed by Digital Equipment Corporation and now under development by Oracle Corporation. Oracle Rdb is a production system that supports the most demanding database applications, runs on multiple platforms and in a variety of environments.
Real-time thresholding with Euler numbers
Authors: L. Snidaro, G. L. Foresti
Venue: Pattern Recognition Letters (2003)

The problem of finding an automatic thresholding technique is well known in applications involving image differencing like visual-based surveillance systems, autonomous vehicle driving, etc. Among the algorithms proposed in the past years, the thresholding technique based on the stable Euler number method is considered one of the most promising in terms of visual results. Unfortunately its high computational complexity made it an impossible choice for real-time applications. The implementation here proposed, called fast Euler numbers, overcomes the problem since it calculates all the Euler numbers in just one single raster scan of the image. That is, it runs in O(hw), where h and w are the image's height and width, respectively. A technique for determining the optimal threshold, called zero crossing, is also proposed.
A Simplex-Based Tabu Search Method for Capacitated Network Design
Authors: Teodor Gabriel Crainic, Michel Gendreau, Judith M. Farvolden
Venue: INFORMS Journal on Computing (2000)

The fixed charge capacitated multicommodity network design problem is a well-known problem, of both practical and theoretical significance. This paper presents an efficient procedure to determine tight upper bounds on the optimal solution of realistically sized problem instances. Feasible solutions are obtained by using a tabu search framework that explores the space of the continuous flow variables by combining pivot moves with column generation, while evaluating the actual mixed integer objective. Computational experiments on a large set of randomly generated test problems show that this procedure outperforms the other available methods and is particularly suited to large problem instances with many commodities.
Variation of rainwater quality due to interactive mass transfer between raindrops and atmosphere
Authors: S. Shiba, Y. Hirata, S. Yagi
Venue: Development and application of computer techniques to environmental studies (2002)

In order to investigate the acidification of raindrops due to washout (below cloud scavenging) of air pollutants, the characteristics of interactive mass transfer between raindrops and the atmosphere is simulated numerically with use of a mathematical model. This is based on the idea that the chemical species concentration of not only the raindrop but also the atmosphere controls washout of pollutants interactively. The model equations are derived from the mass conservation of chemical species in liquid phase (raindrops) and gas phase (the atmosphere), taking account of the time and space variations of the atmospheric concentration due to the interactive mass transfer, which is usually not considered for simplicity.The numerical results show that: (1) the distribution feature of the atmospheric concentration varies considerably with the physical properties of chemicals; (2) the later the raindrop falling is, the lower the raindrop H+ concentration becomes and the less the raindrop is acidified; and (3) the acidity prediction error due to neglecting the interactive mass transfer grows more and more with passage of time.
Multi-objective abstract data type refinement for mapping tables in telecom network applications
Authors: Ch. Ykman-Couvreur, J. Lambrecht, A. van der Togt, F. Catthoor
Venue: ACM SIGPLAN Notices (2003)

We present a new multi-objective exploration method at the system level to select customized implementations for mapping tables, dynamically allocated, as encountered in telecom network, database, and multimedia applications. Our method fits in the context of embedded system synthesis for such applications, and it enables the optimization of the system-level memory management of these applications. To this end it mainly aims at trading off the average memory footprint, number of memory accesses, and memory power. Compared with existing methods, for large mapping tables, 90% (resp. 80%) of the average memory footprint (resp. power) can be saved, without decreasing the performance.
Stability and instability in discrete tomography
Authors: Andreas Alpers, Peter Gritzmann, Lionel Thorens
Venue: Digital and image geometry: advanced lectures (2001)

The paper gives strong instability results for a basic reconstruction problem of discrete tomography, an area that is particularly motivated by demands from material sciences for the reconstruction of crystalline structures from images produced by quantitative high resolution transmission electron microscopy. In particular, we show that even extremely small changes in the data may lead to entirely different solutions. We will also give some indication of how one can possibly handle the ill-posedness of the reconstruction problem in practice.
Observations on the monoidal t-norm logic
Authors: Petr Hájek
Venue: Fuzzy Sets and Systems (2002)

The paper is a contribution to the theory of the monoidal t-norm based logic MTL and stronger logics analogous to the well-known extensions of the basic fuzzy logic (Lukasiewicz, Gödel and product logic). Main attention is payed to the logic IIMTL (MTL plus the characteristic axioms II1, II2 of product logic).
EyePliances: attention-seeking devices that respond to visual attention
Authors: Jeffrey S. Shell, Roel Vertegaal, Alexander W. Skaburskis
Venue: CHI '03 extended abstracts on Human factors in computing systems (2003)

We present EyePliances: appliances and devices that detect and respond to human visual attention using eye contact sensors. EyePliances receive implicit input from users, in the form of eye gaze, and respond by opening communication channels. By allowing devices to recognize the attentional cues people already provide, requests for explicit input from users can be reduced. Further, eye contact sensing gives devices a mechanism to determine whether a user is available for interruption, and can provide the missing environmental context to improve speech recognition.
Singular integral equations method for computations of the scattering characteristics of a model heart exposed to electromagnetic radiation
Authors: L. Knisevskaja, V. Engelson, K.-F. Berggren
Venue: Applied Mathematics and Computation (2003)

The singular integral equations method elaborated in this paper allows us to solve accurately the Maxwell's equations for a three-dimensional (3D) model heart exposed to electromagnetic radiation in the frequency range SHF and EHF. To test our algorithm we have computed the back scattering cross-section for a metal disc. Our computations are in good agreement with experiment given in literature. To demonstrate the usefulness of the algorithm we have computed the scattering characteristics of a simplified model of the human heart. This model is composed of the myocardium, the right and left atria and ventricles. All surfaces of the model are defined a triangular mesh in 3D covering the heart surfaces and normals →n to the triangles.
Automating Scenario-Driven Structured Requirements Engineering
Authors: Hong Zhu, Lingzi Jin
Venue: 24th International Computer Software and Applications Conference (2000)

Scenario analysis is a vehicle of separating concerns in the elicitation of users' requirements. It is also a means of requirements validation and verification. In the practical application of the method, a number of key activities must be supported by automated tools, which include: (a) the analysis of consistency among scenarios, (b) the analysis of the consistency and completeness of a set of scenarios with respect to requirements models, (c) the synthesis of requirements models from a set of scenarios, and (d) the generation of scenarios from requirements models for requirements validation. This paper presents an automatic toolkit that supports these activities. It adapts the idea of scenario analysis originally proposed in OO analysis to the structured analysis method.
Bayesian networks for discrete multivariate data: an algebraic approach to inference
Authors: J. Q. Smith, J. Croft
Venue: Journal of Multivariate Analysis (2003)

In this paper we demonstrate how Gröbner bases and other algebraic techniques can be used to explore the geometry of the probability space of Bayesian networks with hidden variables. These techniques employ a parametrisation of Bayesian network by moments rather than conditional probabilities. We show that whilst Gröbner bases help to explain the local geometry of these spaces a complimentary analysis, modelling the positivity of probabilities, enhances and completes the geometrical picture. We report some recent geometrical results in this area and discuss a possible general methodology for the analyses of such problems.
The effect of individual differences on computer attitudes
Authors: Claudia Orr, David Allen, Sandra Poindexter
Venue: Advanced topics in end user computing (2002)

Computer competency is no longer a skill to be learned only by students majoring in technology-related fields. All individuals in our society must acquire basic computer literacy to function successfully. Despite the wide-spread influx of technology in all segments of our society, the literature often reports high levels of anxiety and negative attitudes about using computers. Monitoring the computer attitudes and developing an understanding of the variables that affect computer attitudes will assist educators and adult trainers in providing appropriate learning experiences in which learners can succeed. This study examined the relationship between computer attitude and experience, demographic/educational variables, personality type, and learning style of 214 students enrolled in a university computer literacy course.
Summed squared distance error reduction by simultaneous multiprojections and applications
Authors: Yair Censor, Nir Cohen, Tuvia Kutscher, Joseph Shamir
Venue: Applied Mathematics and Computation (2002)

A parallel projection scheme in which projections are performed simultaneously on all constraints at each iteration is presented. It is a multiprojections scheme because different distance functions can be minimized for each projection as long as they are based on weighted L2 norms. The use of multiple distance functions enables simplifications of the various projection operations, leading to an efficient implementation of this algorithm. This is true especially for constrained deconvolution type problems. Due to the inherent parallelism of the algorithm, projections onto more than two sets can be performed, even if one (or more) of the sets are nonconvex, maintaining a monotone decrease of a cost functional (with no further restrictions). This is in contrast to the serial projections onto convex sets (POCS) algorithm where no more than two sets can be treated if one of the sets is nonconvex. Our method is a special case of a multiprojections method proposed by Censor and Elfving where generalized distance functions of the Bregman type are used. The restriction to weighted L2 norms leads to a simple and explicit form of this algorithm and allows relaxation and the use of nonconvex sets.
On Organizational Becoming: Rethinking Organizational Change
Authors: Haridimos Tsoukas, Robert Chia
Venue: Organization Science (2002)

Traditional approaches to organizational change have been dominated by assumptions privileging stability, routine, and order. As a result, organizational change has been reified and treated as exceptional rather than natural. In this paper, we set out to offer an account of organizational change on its own terms--to treat change as the normal condition of organizational life. The central question we address is as follows: What must organization(s) be like if change is constitutive of reality? Wishing to highlight the pervasiveness of change in organizations, we talk about organizational becoming. Change, we argue, is the reweaving of actors' webs of beliefs and habits of action to accommodate new experiences obtained through interactions. Insofar as this is an ongoing process, that is to the extent actors try to make sense of and act coherently in the world, change is inherent in human action, and organizations are sites of continuously evolving human action. In this view, organization is a secondary accomplishment, in a double sense. Firstly, organization is the attempt to order the intrinsic flux of human action, to channel it towards certain ends by generalizing and institutionalizing particular cognitive representations. Secondly, organization is a pattern that is constituted, shaped, and emerging from change. Organization aims at stemming change but, in the process of doing so, it is generated by it. These claims are illustrated by drawing on the work of several organizational ethnographers. The implications of this view for theory and practice are outlined.
Improved Design of Queueing Simulation Experiments with Highly Heteroscedastic Responses
Authors: Russell C. H. Cheng, Jack P. C. Kleijnen
Venue: Operations Research (1999)

Simulation experiments for analysing the steady-state behaviour of queueing systems over a range of traffic intensities are considered, and a procedure is presented for improving their design. In such simulations the mean and variance of the response output can increase dramatically with traffic intensity; the design has to be able to cope with this complication. A regression metamodel of the likely mean response is used consisting of two factors, namely, a low-degree polynomial and a factor accounting for the exploding mean as the traffic intensity approaches its saturation. The best choice of traffic intensities at which to make simulation runs depends on the variability of the simulation output, and this variability is estimated using analytical heavy traffic results. The optimal numbers of customers simulated at each traffic intensity are built up using a multistage procedure. The asymptotic properties of the procedure are investigated theoretically. The procedure is shown to be robust and to be more efficient than more naive procedures. A result of note is that even when the range of interest includes high traffic intensities, the highest traffic load simulated should remain well away from its upper limit; but the number of customers simulated should be concentrated at the higher traffic intensities used. Empirical results are included for simulations of a single server queue with different priority rules and for a complicated queueing network. These results support the theoretical results, demonstrating that the proposed procedure can increase the accuracy of the estimated metamodel significantly compared with more naive methods.
Interval Protection of Confidential Information in a Database
Authors: Ram D. Gopal, Paulo B. Goes, Robert S. Garfinkel
Venue: INFORMS Journal on Computing (1998)

We deal with the question of how to maintain security of confidential information in a database while answering as many queries as possible. The database is assumed to operate in a query restriction (as opposed to perturbation) mode in which exact answers are given to those queries which, together with those already answered, will not compromise any confidential datum. Those which fail this criterion are not answered. We introduce the concept of interval disclosure where a datum is compromised if the answered queries provide enough information to establish that it is contained in a given interval even if the datum cannot be determined exactly. Models are presented for the problem of deciding whether to answer a query and three techniques, one based on linear programming, are developed and tested.
An extension of Bar-Hen's preliminary test procedure
Authors: Radosław Kala, Mirosław Krzyśko
Venue: Journal of Multivariate Analysis (2003)

An asymptotic test procedure, proposed by Bar-Hen (J. Multivariate Anal. 57 (1996) 266), for deciding if a given set of data represents a new population or one of k a priori known populations, is extended to the case when the new population is described by more than one parameter.
Bringing Work Back In
Authors: Stephen R. Barley, Gideon Kunda
Venue: Organization Science (2001)

In this essay we argue that organization theory's effort to make sense of postbureaucratic organizing is hampered by a dearth of detailed studies of work. We review the history of organization theory to show that, in the past, studies of work provided an empirical foundation for theories of bureaucracy, and explain how such research became marginalized or ignored. We then discuss methodological requirements for reintegrating work studies into organization theory and indicate what the conceptual payoffs of such integration might be. These payoffs include breaking new conceptual ground, resolving theoretical puzzles, envisioning organizing processes, and revitalizing old concepts.
Facial expression recognition: a clustering-based approach
Authors: Xue-wen Chen, Thomas Huang
Venue: Pattern Recognition Letters (2003)

This paper describes a new clustering based feature extraction method for facial expression recognition. We demonstrate the effectiveness of this method and compare it with commonly used principal component analysis method and linear discriminant analysis method.
Numerical Methods for Fitting and Simulating Autoregressive-To-Anything Processes
Authors: Marne C. Cario, Barry L. Nelson
Venue: INFORMS Journal on Computing (1998)

An ARTA (AutoRegressive-to-Anything)Process is a time series with arbitrary marginal distribution and autocorrelation structure specified through finite lag p. We develop an efficient numerical method forfitting ARTA processes and discuss its implementation in the software ARTAFACTS. We also present the software ARTAGEN that generates observations from ARTA processes for use as inputs to a computer simulation. We illustrate the use of the software with a real-world example.
Evacuation planning and spatial decision making: designing effective spatial decision support systems through integration of technologies
Authors: F. N. de Silva, R. W. Eglese, M. Pidd
Venue: Decision making support systems: achievements, trends and challenges for (2002)

Issues concerning the development of Spatial Decision Systems for evacuation planning include realistic modelling of evacuee behavior, decision-making processes that take place during an evacuation, logistics, generating realistic scenarios, validation, technology development and trends for the future. These issues are discussed with reference to the development of a prototype system called CEMPS, which integrates simulation and GIS technology for emergency planning.
Computation and homotopical applications of induced crossed modules
Authors: Ronald Brown, Christopher D. Wensley
Venue: Journal of Symbolic Computation (2003)

We explain how the computation of induced crossed modules allows the computation of certain homotopy 2-types and, in particular, second homotopy groups. We discuss various issues involved in computing induced crossed modules and give Some examples and applications.
Kolmogorov ε-Entropy in the Problems on Global Attractors for Evolution Equations of Mathematical Physics
Authors: M. I. Vishik, V. V. Chepyzhov
Venue: Problems of Information Transmission (2003)

We study the Kolmogorov &epsiv;-entropy and the fractal dimension of global attractors for autonomous and nonautonomous equations of mathematical physics. We prove upper estimates for the &epsiv;-entropy and fractal dimension of the global attractors of nonlinear dissipative wave equations.