1,720,994 research outputs found
Slide: A Useful Special Case of the Cardpath Constraint
No full textWe study the cardpath constraint. This ensures a given constraint
holds a number of times down a sequence of variables. We show that slide, a special case of cardpath where the slid constraint must hold always, can be used to encode a wide range of sliding sequence constraints including cardpath itself. We consider how to propagate slide and provide a complete propagator for cardpath . Since propagation is NP-hard in general, we identify special cases where propagation takes polynomial time. Our experiments demonstrate that using slide to encode global constraints can be as efficient and effective as specialised propagators
The Fifth Workshop on Modelling and Solving Problems with Constraints. Held at the Nineteenth International Joint Conference on Artificial Intelligence ( IJCAI 2005 ), Edindurgh, Scotland, 31 July, 2005.
No full textConstraint Programming (CP) is a powerful technology to solve combinatorial problems which are ubiquitous in academia and industry. The last ten years have witnessed significant research devoted to modelling and solving problems with constraints. CP is now a mature field and has been successfully used for tackling a wide range of real-life complex applications.
As constraint solving is intractable in general, problems can become difficult to solve as their size increase. Therefore, there is always a need for more efficient solvers to cope with ever difficult problems. Techniques such as the design of specialised filtering algorithms for recurring constraints, sophisticated search techniques, heuristics to guide the search, symmetry breaking have significant impact on the time spent to solve problems. Efficiency can be improved also by bridging the gap between CP and the other communities such as Operations Research, Local Search, SAT, Planning, and Machine Learning.
Formulating an effective model for a given problem often requires trying alternate models and using ``modelling tricks'' such as redundant modelling and channelling. This could be a challenge even for modelling experts. The increasing use of CP necessitates higher level modelling languages to facilitate the exploitation of the available technology and to make CP reachable to a wider user base. The hope is that the next generation modelling languages will assist modellers by for instance helping acquire and validate constraints, automatically generating alternate models and selecting the most appropriate one for the application in hand, and synthesising propagators for complex constraints.
It is desirable to extend the classical framework for modelling and solving with constraints to adapt to some real-life scenarios. For instance, many problems contain uncertainty and thus the user may require robust solutions. In some cases, problems are over-constrained and the user has preferences for which constraints to relax. Explanations can be necessary to understand the solution process. Real-life problems are often optimisation problems and the users might want to improve the quality of their solutions as quickly as possible.
The rapidly growing use of CP in industrial applications makes it crucial to fill the gap between the user's needs and the answers provided by the technology. Developing more efficient ways to solve constraints, assisting the users in the modelling phase, and extending the classical modelling and solving framework to capture real-life scenarios are important steps towards a better applicability of CP technology to real-life problems. This one-day workshop will address modelling and solving jointly, looking for ways to enrich the efficiency, usability and the expressiveness of the CP tools. It will interest both academics in the AI community working on constraint reasoning, and people in industry using CP technology to solve problems.
Workshop topics include (but are not limited to):
* filtering algorithms
* synthesising propagators
* symmetry and constraints
* search algorithms and heuristics
* local and hybrid search
* modelling
* constraint acquisition and validation
* model generation and selection
* preferences
* optimization and over-constrained problems
* uncertainty and robustness
* explanations
* real-life applications
This workshop is the fifth in the series, following the successful earlier workshops held alongside ECAI 2000, IJCAI 2001, ECAI 2002, and ECAI 2004. There have also been related workshops at CP 2001/2002/2003/2004, IJCAI 1999/2003 and ECAI 1998.
URL: http://homes.ieu.edu.tr/~bhnich/ijcai05ws
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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