Introduction to Two Dimensional Kinematics

Introduction to Two Dimensional Kinematics tài liệu, giáo án, bài giảng , luận văn, luận án, đồ án, bài tập lớn về tất c...

Proceedings of the COLING/ACL 2006 Main Conference Poster Sessions, pages 905–912, Sydney, July 2006. c 2006 Association for Computational Linguistics A Grammatical Approach to Understanding Textual Tables using Two-Dimensional SCFGs Dekai WU 1 Ken Wing Kuen LEE Human Language Technology Center HKUST Department of Computer Science and Engineering University of Science and Technology Clear Water Bay, Hong Kong {dekai,cswkl}@cs.ust.hk Abstract We present an elegant and extensible model that is capable of providing seman- tic interpretations for an unusually wide range of textual tables in documents. Un- like the few existing table analysis mod- els, which largely rely on relatively ad hoc heuristics, our linguistically-oriented ap- proach is systematic and grammar based, which allows our model (1) to be concise and yet (2) recognize a wider range of data models than others, and (3) disambiguate to a significantly finer extent the under- lying semantic interpretation of the table in terms of data models drawn from rela- tion database theory. To accomplish this, the model introduces Viterbi parsing under two-dimensional stochastic CFGs. The cleaner grammatical approach facilitates not only greater coverage, but also gram- mar extension and maintenance, as well as a more direct and declarative link to se- mantic interpretation, for which we also introduce a new, cleaner data model. In disambiguation experiments on recogniz- ing relevant data models of unseen web ta- bles from different domains, a blind evalu- ation of the model showed 60% precision and 80% recall. 1 Introduction Natural language processing has historically tended to emphasize understanding of linear strings—sentences, paragraphs, discourse struc- ture. The vast body of work that focuses on text understanding is often seen as an approximation of 1 The authors would like to thank the Hong Kong Re- search Grants Council (RGC) for supporting this research in part through grants RGC6083/99E, RGC6256/00E, and DAG03/04.EG09. spoken language understanding. Yet real-life text is actually heavily dependent on visual layout and formatting, which compensate for cues normally found in spoken language but are absent in text. As Scott (2003) reiterated in the opening ACL’03 invited talk: “The overlay of graphics on text is in many ways equivalent to the overlay of prosody on speech Just as prosody undoubtedly contributes to the meaning of utterances, so too does a text’s graphical presentation contribute to its meaning. However few natural language understanding systems use graphical presentational features to aid interpretation ” (Power et al., 2003). Nowhere is this more evident than in the wide- spread use of tables in real-world, unsimplified text documents. Tables have a comparable or greater complexity as other elements of text. Un- fortunately, in mainstream NLP it is not uncom- mon for tables to be regarded as a somehow “de- generate” form of text, unworthy of the same de- gree of attention as the rest of the text. But as we will discuss, the degree of ambiguity in ta- ble understanding is at least as great as for many sense and attachment problems. Many of the same mechanisms used for understanding linear text are also required for table understanding. The same division of surface syntax and underlying seman- tics is found. Indeed, to perceive the limitations of existing table understanding models, we may distinguish several very different levels of table analysis tasks. In table classification, the table is classified into one of several coarse categories (in the extreme case, some models simply predict whether the pur- pose of the table is for page layout versus tabular data). In table synactic recognition, the surface types of individual cells or block regions are la- beled (e.g., as heading Introduction to Two-Dimensional Kinematics Introduction to TwoDimensional Kinematics Bởi: OpenStaxCollege Everyday motion that we experience is, thankfully, rarely as tortuous as a rollercoaster ride like this—the Dragon Khan in Spain’s Universal Port Aventura Amusement Park However, most motion is in curved, rather than straight-line, paths Motion along a curved path is two- or threedimensional motion, and can be described in a similar fashion to one-dimensional motion (credit: Boris23/Wikimedia Commons) The arc of a basketball, the orbit of a satellite, a bicycle rounding a curve, a swimmer diving into a pool, blood gushing out of a wound, and a puppy chasing its tail are but a few examples of motions along curved paths In fact, most motions in nature follow curved paths rather than straight lines Motion along a curved path on a flat surface or a plane (such as that of a ball on a pool table or a skater on an ice rink) is two-dimensional, and thus described by two-dimensional kinematics Motion not confined to a plane, such as a car following a winding mountain road, is described by three-dimensional kinematics Both two- and three-dimensional kinematics are simple extensions of the one-dimensional kinematics developed for straight-line motion in the previous chapter This simple extension will allow us to apply physics to many more situations, and it will also yield unexpected insights about nature 1/1 I.D.Chueshov D issipative S ystems Infinite-Dimensional Introduction Theory I. D. Chueshov Introduction to the Theory of InfiniteDimensional Dissipative Systems 966–7021–64–5 ORDER www.acta.com.ua I . D . Chueshov Chueshov Universitylecturesincontemporarymathematics D issipative issipative S ystems ystems of Infinite-Dimensional Infinite-Dimensional Introduction ntroduction Theory Theory to the This book provides an exhau - stive introduction to the scope of main ideas and methods of the theory of infinite-dimensional dis - sipative dynamical systems which has been rapidly developing in re - cent years. In the examples sys tems generated by nonlinear partial differential equations arising in the different problems of modern mechanics of continua are considered. The main goal of the book is to help the reader to master the basic strategies used in the study of infinite-dimensional dissipative systems and to qualify him/her for an independent scien - tific research in the given branch. Experts in nonlinear dynamics will find many fundamental facts in the convenient and practical form in this book. The core of the book is com - posed of the courses given by the author at the Department of Me chanics and Mathematics at Kharkov University during a number of years. This book con - tains a large number of exercises which make the main text more complete. It is sufficient to know the fundamentals of functional analysis and ordinary differential equations to read the book. Translated by Constantin I. Chueshov from the Russian edition («ACTA», 1999) Translation edited by Maryna B. Khorolska Author: I. D. Chueshov I. D. Chueshov Title: Introduction to the Theory Introduction to the Theory of InfiniteDimensional of InfiniteDimensional Dissipative Systems Dissipative Systems ISBN: 966–7021–64–5 You can ORDER ORDER this book while visiting the website of «A CTA» Scientific Publishing House http://www.acta.com.ua www.acta.com.ua /en/ « A CTA » 2002 I. D. Chueshov Introduction IntroductionIntroduction Introduction to the Theory of Infinite-Dimensional to the Theory of Infinite-Dimensionalto the Theory of Infinite-Dimensional to the Theory of Infinite-Dimensional Dissipative Systems Dissipative SystemsDissipative Systems Dissipative Systems A CTA 2002 UDC 517 2000 Mathematics Subject Classification: primary 37L05; secondary 37L30, 37L25. This book provides an exhaustive introduction to the scope of main ideas and methods of the theory of infinite-dimen- sional dissipative dynamical systems which has been rapidly developing in recent years. In the examples systems genera- ted by nonlinear partial differential equations arising in the different problems of modern mechanics of continua are con- sidered. The main goal of the book is to help the reader to master the basic strategies used in the study of infinite-di- mensional dissipative systems and to qualify him/her for an independent scientific research in the given branch. Experts in nonlinear dynamics will find many fundamental facts in the convenient and practical form in this book. The core of the book is composed of the courses given by the author at the Department of Mechanics and Mathematics at Kharkov University during a number of years. This book contains a large number of exercises which make the main text more complete. It is sufficient to know the fundamentals of functional analysis Revue Contribution of two-dimensional electrophoresis of proteins to maritime pine genetics N Bahrman. C Plomion RJ Petit. A Kremer Laboratoire de Génétique et Amélioration des arbres forestiers, Inra, BP 45, F-33611 Gazinet cedex, France (Received 24 November 1995; accepted 17 June 1996) Summary - Several investigations undertaken on maritime pine genetics using two-dimensional gel electrophoresis of megagametophyte, collected from germinated or non-germinated seed, needle, bud and pollen proteins, are reviewed in the present paper. Different extraction methods adapted to each tissue or organ allowed reproducible protein patterns to be obtained. Genetic studies deal with genetic diversity, differential genome expression and genome mapping. Using 16 protein loci, the allelic frequencies were scored and the mean genetic diversity and differentiation were estimated in 192 indi- viduals from six different origins. Proteins whose expression is restricted to a single organ were shown to be more variable than unspecific proteins in a study comparing needle, bud and pollen proteins from 18 unrelated trees. The level of variability was slightly higher in the bud than that in the needle or the pollen. Moreover, larger proteins were shown to display more allelic diversity than proteins having a lower molecular weight. Ninety protein loci were found polymorphic in megaga- metophyte (haploid tissue) and were used to construct a linkage map containing 12 linkage groups. Twenty-seven and 17 protein loci showing Mendelian segregation in germinated seed megagame- tophyte and in needles of an F2 progeny, respectively, were introduced in another linkage map con- taining 436 random amplified polymorphic DNA (RAPD) markers. These studies outline the usefulness of the two-dimensional gel electrophoresis technique in genetic studies of conifers. diversity / linkage map / genome expression / 2D PAGE / Pinus pinaster Résumé - Apport de l’électrophorèse bidimensionnelle des protéines de mégagamétophytes à la génétique du pin maritime. Dans cet article de synthèse, nous présentons les recherches effectuées sur la génétique du pin maritime, en utilisant l’électrophorèse bidimensionnelle des protéines de mégagamétophytes prélevés sur des graines germées et non germées, d’aiguilles, de bourgeons et de pollens. Plusieurs méthodes d’extraction ont été utilisées afin d’obtenir des diagrammes protéiques reproductibles. Les études génétiques concernent la diversité génétique, l’expression différentielle du génome et la cartographie génétique. En utilisant 16 locus protéiques, les fréquences alléliques, la diver- * Correspondence and reprints Tel: (33) 05 57 97 90 76; fax: (33) 05 57 97 90 88; e-mail: plomion@pierroton.inra.fr sité génétique moyenne et la différentiation ont été calculées sur 192 individus de six origines dif- férentes. Dans une étude concernant les aiguilles, bourgeons et pollens de 18 génotypes non apparentés, les bourgeons sont un peu plus variables que les deux autres organes ; par ailleurs les protéines spé- cifiques d’un organe sont plus variables que les protéines communes. Les protéines de haut poids molé- culaire montrent plus de variation allélique que celles de petit poids moléculaire. Quatre-vingt dix mar- queurs polymorphes du mégagamétophyte ont été cartographiés dans 12 groupes de liaisons. Dans une autre carte, 27 et 17 protéines polymorphes extraites respectivement de mégagamétophytes et d’aiguilles d’une famille F2 ont été cartographiées avec 436 marqueurs RAPDs. Ces études Two Dimensional Colloidal Assembly under an Alternating Electric Field: from Introduction to Structure LIU YU (B.Sc., Xiamen University) A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF PHYSICS NATIONAL UNIVERSITY OF SINGAPORE 2008 Acknowledgements I would like to express my gratitude to my supervisors, Prof. Liu Xiang-Yang, and A/P Janaky Narayanan for their instructive and patient supervision throughout this project. I am also grateful to Dr. Zhang Ke-Qin for the enlightening instructions. I take this opportunity to express my gratitude to Dr. Christina Strom who has contributed a lot through my PhD study. I owe much to her for helping me throughout the period of my research by providing advice, support and editing the papers. I gratefully acknowledge the financial supports from the National University of Singapore. I also gratefully acknowledge the help and support of all my fellow lab mates, past and present, who have spent countless hours of insightful discussion. I am pleased to thank all of you, Yanwei, Huaidong, Huiping, Dawei, Junying, Junxue, Jingliang, Perry, Junfeng, Du Ning, Rongyao, Yanhua, Tianhui, Zhou Kun, Gangqin, Xiaodan, Yang Zheng, Tingting, Wang Lei, Xiuzhong, Rongguo, Dai Liang, and Li Yang. Special thanks are due to Mr. Teo, Eric, and Michael for their support and i help throughout my research work, as well as many other close friends that could not fit in the available space. I would like to thank those closest to me, especially Sun Han, Zhuang Ying, Xiaoju, Liu Yan, Guowen, Wang Peng, and aunt Zhang, whose presence helped me to complete my graduate work and made me feel at home, I extend them my deepest appreciation. Last but not least, I would like to express my deepest gratefulness to my family, in particular, my mother Zhang Zhi-Min, my father Liu He-Ping, and my husband Xie Rong-Guo for their endless support and encouragement. ii Table of Contents Acknowledgements Summary Publications i vi viii List of Tables ix List of Figures x Introduction 1.1 Colloidal System . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Implications and Applications . . . . . . . . . . . . . . . . . . . . . 1.3 Self-Assembly Strategies for Colloid Arrays . . . . . . . . . . . . . . 1.4 Review on 2D Colloidal Assembly under an Alternating Current Electric Field . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1.5 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 1.6 Scope and Summary . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Techniques, Materials and Data Analysis 2.1 Experimental Techniques . . . . . . . . . . . . . . . . . . . . . . . . 25 25 iii 2.2 2.1.1 Experimental Setup . . . . . . . . . . . . . . . . . . . . . . . 25 2.1.2 Zetasizer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 2.1.3 Temperature Control System . . . . . . . . . . . . . . . . . 31 2.1.4 Scanning Electron Microscope . . . . . . . . . . . . . . . . . 31 Data Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 2.2.1 Radial Pair Correlation Function g 2D (r) . . . . . . . . . . . 35 2.2.2 Bond-orientational Correlation Function g6 (r) . . . . . . . . 35 Mechanism of 2D Colloidal Assembly under an AC Field 37 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 3.2 Experiments and Data Analysis . . . . . . . . . . . . . . . . . . . . 39 3.3 Colloidal Assembly under an AC Field . . . . . . . . . . . . . . . . 41 3.3.1 Phase Behaviors of Colloidal Particles at different Zeta Potentials, Field Strengths and Frequencies . . . . . . . . . . . 41 3.3.2 Effects of Ionic Strength and Salt Specificity . . . . . . . . . 45 3.3.3 The Role Played by the Particle Size on Colloidal Assembly 48 3.4 Discussions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 3.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . .