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Lincoln Wallen

Bio: Lincoln Wallen is an academic researcher from University of Edinburgh. The author has contributed to research in topics: Parsing & Parser combinator. The author has an hindex of 11, co-authored 66 publications receiving 715 citations.

Papers published on a yearly basis

Papers
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Book ChapterDOI
01 Jan 1984
TL;DR: Two programs are provided, one that generates Ipc and autocorrelation coefficients from the speech utterances and the other that, using dynamic programming, compares the test utterance with the reference utterance and finds the best match.
Abstract: Two programs are provided, one that generates Ipc and autocorrelation coefficients from the speech utterances and the other that, using dynamic programming, compares the test utterance with the reference utterances and finds the best match. The method used is Constrained Endpoint with 2-to-l range of slope.

412 citations

Book ChapterDOI
01 Jan 1984
TL;DR: RUP’s TMS aiso ensures that there is an entry on a contradiction queue for every propositional clause all of whose atoms are false.
Abstract: A truth maintenance system (TMS) is used to record justifications for assertions. Such justifications can be used to generate explanations and to track down the assumptions underlying assertions. In RUP every justification is a disjunctive clause of sentential (propositional) atoms and any such clause can be treated as a justification. RUP’s TMS takes a set of such propositional clauses and performs propositional constraint propagation to ensure that every assertion with a valid justification is in fact believed by the system (thus ensuring a deduction invariant). RUP’s TMS aiso ensures that there is an entry on a contradiction queue for every propositional clause all of whose atoms are false.

115 citations

Book ChapterDOI
01 Jan 1984
TL;DR: This is a theory of evidence potentially suitable for knowledge-based systems based on “basic probabilities” which can be visualized as probability masses that are constrained to stay within the subset with which they are associated, but are free to move over every point in the subset.
Abstract: This is a theory of evidence potentially suitable for knowledge-based systems. The system is based on “basic probabilities” which can be visualized as probability masses that are constrained to stay within the subset with which they are associated, but are free to move over every point in the subset. From these basic probabilities we can derive upper and lower probabilities (Dempster) or belief functions and plausibilities (Shafer). The means of combining basic probabilities is using Dempster’s Rule which is valid given independent evidences. A position of complete ignorance about an hypothesis is represented by having an upper probability of one and a lower probability of zero. Complete certainty about the probability of an hypothesis is represented when the upper and lower probabilities are equal. The approach can suffer from high computation times, although this can be reduced when each piece of evidence confirms or denies a single proposition rather than a disjunction. The method has been extended to allow fuzzy subsets as an expression of knowledge.

89 citations

Book ChapterDOI
01 Jan 1984
TL;DR: An uninformed graph searching strategy in which each level is searched before going to the next deeper level, which guarantees finding the shortest path to the node sought first.
Abstract: An uninformed graph searching strategy in which each level is searched before going to the next deeper level. This strategy guarantees finding the shortest path to the node sought first: any path to the solution that is of length n will be found when the search reaches depth n, and this is guaranteed to be before any node of depth < n is searched.

64 citations

Book ChapterDOI
01 Jan 1984
TL;DR: An uninformed graph searching strategy which searches the graph by exploring each possible path through it until either the required solution or a previously encountered node is encountered, which is neither guaranteed to produce the shortest path to the solution if one exists, nor to find a solution evenif one exists.
Abstract: An uninformed graph searching strategy which searches the graph by exploring each possible path through it until either the required solution or a previously encountered node is encountered. The nodes are expanded in order of depth; with the deepest node expanded first and nodes of equal depth expanded in an arbitrary order. To prevent searching of an infinite path, a depth-bound is usually fixed and nodes below this depth are never generated, thus the strategy is neither guaranteed to produce the shortest path to the solution if one exists, nor to find a solution even if one exists.

48 citations


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Book
01 Apr 2003
TL;DR: This chapter discusses methods related to the normal equations of linear algebra, and some of the techniques used in this chapter were derived from previous chapters of this book.
Abstract: Preface 1. Background in linear algebra 2. Discretization of partial differential equations 3. Sparse matrices 4. Basic iterative methods 5. Projection methods 6. Krylov subspace methods Part I 7. Krylov subspace methods Part II 8. Methods related to the normal equations 9. Preconditioned iterations 10. Preconditioning techniques 11. Parallel implementations 12. Parallel preconditioners 13. Multigrid methods 14. Domain decomposition methods Bibliography Index.

13,484 citations

Journal ArticleDOI
TL;DR: This paper surveys the recent advances in multimodal machine learning itself and presents them in a common taxonomy to enable researchers to better understand the state of the field and identify directions for future research.
Abstract: Our experience of the world is multimodal - we see objects, hear sounds, feel texture, smell odors, and taste flavors Modality refers to the way in which something happens or is experienced and a research problem is characterized as multimodal when it includes multiple such modalities In order for Artificial Intelligence to make progress in understanding the world around us, it needs to be able to interpret such multimodal signals together Multimodal machine learning aims to build models that can process and relate information from multiple modalities It is a vibrant multi-disciplinary field of increasing importance and with extraordinary potential Instead of focusing on specific multimodal applications, this paper surveys the recent advances in multimodal machine learning itself and presents them in a common taxonomy We go beyond the typical early and late fusion categorization and identify broader challenges that are faced by multimodal machine learning, namely: representation, translation, alignment, fusion, and co-learning This new taxonomy will enable researchers to better understand the state of the field and identify directions for future research

1,945 citations

Book
01 Jan 2006
TL;DR: Researchers from other fields should find in this handbook an effective way to learn about constraint programming and to possibly use some of the constraint programming concepts and techniques in their work, thus providing a means for a fruitful cross-fertilization among different research areas.
Abstract: Constraint programming is a powerful paradigm for solving combinatorial search problems that draws on a wide range of techniques from artificial intelligence, computer science, databases, programming languages, and operations research. Constraint programming is currently applied with success to many domains, such as scheduling, planning, vehicle routing, configuration, networks, and bioinformatics. The aim of this handbook is to capture the full breadth and depth of the constraint programming field and to be encyclopedic in its scope and coverage. While there are several excellent books on constraint programming, such books necessarily focus on the main notions and techniques and cannot cover also extensions, applications, and languages. The handbook gives a reasonably complete coverage of all these lines of work, based on constraint programming, so that a reader can have a rather precise idea of the whole field and its potential. Of course each line of work is dealt with in a survey-like style, where some details may be neglected in favor of coverage. However, the extensive bibliography of each chapter will help the interested readers to find suitable sources for the missing details. Each chapter of the handbook is intended to be a self-contained survey of a topic, and is written by one or more authors who are leading researchers in the area. The intended audience of the handbook is researchers, graduate students, higher-year undergraduates and practitioners who wish to learn about the state-of-the-art in constraint programming. No prior knowledge about the field is necessary to be able to read the chapters and gather useful knowledge. Researchers from other fields should find in this handbook an effective way to learn about constraint programming and to possibly use some of the constraint programming concepts and techniques in their work, thus providing a means for a fruitful cross-fertilization among different research areas. The handbook is organized in two parts. The first part covers the basic foundations of constraint programming, including the history, the notion of constraint propagation, basic search methods, global constraints, tractability and computational complexity, and important issues in modeling a problem as a constraint problem. The second part covers constraint languages and solver, several useful extensions to the basic framework (such as interval constraints, structured domains, and distributed CSPs), and successful application areas for constraint programming. - Covers the whole field of constraint programming - Survey-style chapters - Five chapters on applications Table of Contents Foreword (Ugo Montanari) Part I : Foundations Chapter 1. Introduction (Francesca Rossi, Peter van Beek, Toby Walsh) Chapter 2. Constraint Satisfaction: An Emerging Paradigm (Eugene C. Freuder, Alan K. Mackworth) Chapter 3. Constraint Propagation (Christian Bessiere) Chapter 4. Backtracking Search Algorithms (Peter van Beek) Chapter 5. Local Search Methods (Holger H. Hoos, Edward Tsang) Chapter 6. Global Constraints (Willem-Jan van Hoeve, Irit Katriel) Chapter 7. Tractable Structures for CSPs (Rina Dechter) Chapter 8. The Complexity of Constraint Languages (David Cohen, Peter Jeavons) Chapter 9. Soft Constraints (Pedro Meseguer, Francesca Rossi, Thomas Schiex) Chapter 10. Symmetry in Constraint Programming (Ian P. Gent, Karen E. Petrie, Jean-Francois Puget) Chapter 11. Modelling (Barbara M. Smith) Part II : Extensions, Languages, and Applications Chapter 12. Constraint Logic Programming (Kim Marriott, Peter J. Stuckey, Mark Wallace) Chapter 13. Constraints in Procedural and Concurrent Languages (Thom Fruehwirth, Laurent Michel, Christian Schulte) Chapter 14. Finite Domain Constraint Programming Systems (Christian Schulte, Mats Carlsson) Chapter 15. Operations Research Methods in Constraint Programming (John Hooker) Chapter 16. Continuous and Interval Constraints(Frederic Benhamou, Laurent Granvilliers) Chapter 17. Constraints over Structured Domains (Carmen Gervet) Chapter 18. Randomness and Structure (Carla Gomes, Toby Walsh) Chapter 19. Temporal CSPs (Manolis Koubarakis) Chapter 20. Distributed Constraint Programming (Boi Faltings) Chapter 21. Uncertainty and Change (Kenneth N. Brown, Ian Miguel) Chapter 22. Constraint-Based Scheduling and Planning (Philippe Baptiste, Philippe Laborie, Claude Le Pape, Wim Nuijten) Chapter 23. Vehicle Routing (Philip Kilby, Paul Shaw) Chapter 24. Configuration (Ulrich Junker) Chapter 25. Constraint Applications in Networks (Helmut Simonis) Chapter 26. Bioinformatics and Constraints (Rolf Backofen, David Gilbert)

1,527 citations

Book
01 Jan 1986
TL;DR: An example of the advantage of intertwining generating and testing can be seen with programs solving the N queens problem, which requires the placement of N pieces on an Nby-N rectangular board so that no two pieces are on the same line.
Abstract: ly, this program guesses nondeterministically the correct permutation via permutation(Xs,Ys), and ordered checks that the permutation is actually ordered. Operationally, the behavior is as follows. A query involving sort is reduced to a query involving permutation and ordered. A failure-driven loop ensues. A permutation of the list is generated by permutation and tested by ordered. If the permuted list is not ordered, the execution backtracks to the permutation goal, which generates another permutation to be tested. Eventually an ordered permutation is generated and the computation terminates. Permutation sort is a highly inefficient sorting algorithm, requiring time super-exponential in the size of the list to be sorted. Pushing the tester into the generator, however, leads to a reasonable algorithm. The generator for permutation sort, permutation, selects an arbitrary element and recursively permutes the rest of the list. The tester, ordered, verifies that the first two elements of the permutation are in order, then recursively checks the rest. If we view the combined recursive permutation and ordered goals as a recursive sorting process, we have the basis for insertion sort, Program 3.21. To sort a list, sort the tail of the list and insert the head of the list into its correct place in the order. The arbitrary selection of an element has been replaced by choosing the first element. Another example of the advantage of intertwining generating and testing can be seen with programs solving the N queens problem. The N queens problem requires the placement of N pieces on an Nby-N rectangular board so that no two pieces are on the same line: horizontal, vertical, or diagonal. The original formulation called for 8 queens to be placed on a chessboard, and the criterion of not being on the same line corresponds to two queens not attacking each other under the rules of chess. Hence the problem's name. 253 Nondeterministic Programming

1,422 citations

Journal ArticleDOI
TL;DR: A large number of problems in AI and other areas of computer science can be viewed as special cases of the constraint-satisfaction problem, and a number of different approaches have been developed for solving them.
Abstract: A large number of problems in AI and other areas of computer science can be viewed as special cases of the constraint-satisfaction problem. Some examples are machine vision, belief maintenance, scheduling, temporal reasoning, graph problems, floor plan design, the planning of genetic experiments, and the satisfiability problem. A number of different approaches have been developed for solving these problems. Some of them use constraint propagation to simplify the original problem. Others use backtracking to directly search for possible solutions. Some are a combination of these two techniques. This article overviews many of these approaches in a tutorial fashion.

1,069 citations