Exploring Mathematics
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Reference and Book List, Volume 47
Reference and Book List The Reference section of the Notices for the managing editor. Postal mail: [email protected] is intended to provide the reader with addresses may be found in the or [email protected]. frequently sought information in masthead. April 28, 2000: Nominations for an easily accessible manner. New the Maria Mitchell Women in Science information is printed as it becomes Upcoming Deadlines Award. Contact Maria Mitchell Asso- available and is referenced after the April 18, 2000: Proposals for 2001 ciation, 2 Vestal Street, Nantucket, MA first printing. As soon as information 02554; telephone: 508-228-9198; or NSF-CBMS Regional Conferences. See is updated or otherwise changed, it see http://www.mmo.org/. http://www.maa.org/cbms/ will be noted in this section. May 1 and October 1, 2000: Appli- nsf/2000_conf.htm or contact the cations for NSF/AWM Travel Grants Contacting the Notices Conference Board of the Mathemati- for Women. See http://www. The preferred method for contacting cal Sciences, 1529 18th St. NW, Wash- awm-math.org/travelgrants.html; the Notices is electronic mail. The ington, DC 20036-1385; telephone: telephone: 301-405-7892; e-mail: editor is the person to whom to send 202-293-1170; fax: 202-293-3412; e- [email protected]. articles and letters for consideration. Articles include feature articles, Where to Find It Mathematical Sciences Education memorial articles, book reviews and A brief index to information that Board and Staff other communications, columns for appears in this and previous issues of April 2000, p. 495 “Another Opinion”, and “Forum” the Notices. -
Sonobe Assembly Guide for a Few Polyhedra
Model Shape # of Units Finished Unit to Fold Crease Pattern Toshie Takahama’s 3 Jewel Cube 6 Large Cube 12 Octahedral Assembly 12 Icosahedral Assembly 30 Spiked Pentakis Dodecahedral 60 Assembly Dodecahedral 90 Assembly 2 Sonobe Variations Sonobe Assembly Basics Sonobe assemblies are essentially “pyramidized” constructing a polyhedron, the key thing to re- polyhedra, each pyramid consisting of three So- member is that the diagonal ab of each Sonobe nobe units. The figure below shows a generic So- unit will lie along an edge of the polyhedron. nobe unit and how to form one pyramid. When a Pocket Tab Forming one Tab pyramid Pocket b A generic Sonobe unit representation Sonobe Assembly Guide for a Few Polyhedra 1. Toshie’s Jewel: Crease three finished units as tabs and pockets. This assembly is also sometimes explained in the table on page 2. Form a pyramid known as a Crane Egg. as above. Then turn the assembly upside down 2. Cube Assembly: Crease six finished units as and make another pyramid with the three loose explained in the table on page 2. Each face will be made up of 3 the center square of one unit and the tabs of two other units. 4 Do Steps 1 and 2 to form one face. Do Steps 3 and 4 to form one corner or vertex. Continue 1 2 interlocking in this manner to arrive at the finished cube. Sonobe Variations 3 3. Large Cube Assembly: Crease 12 finished units as explained on page 2. 5 6 3 The 12-unit large cube is the only assembly that does not involve pyramidizing. -
Hexaflexagons, Probability Paradoxes, and the Tower of Hanoi
HEXAFLEXAGONS, PROBABILITY PARADOXES, AND THE TOWER OF HANOI For 25 of his 90 years, Martin Gard- ner wrote “Mathematical Games and Recreations,” a monthly column for Scientific American magazine. These columns have inspired hundreds of thousands of readers to delve more deeply into the large world of math- ematics. He has also made signifi- cant contributions to magic, philos- ophy, debunking pseudoscience, and children’s literature. He has produced more than 60 books, including many best sellers, most of which are still in print. His Annotated Alice has sold more than a million copies. He continues to write a regular column for the Skeptical Inquirer magazine. (The photograph is of the author at the time of the first edition.) THE NEW MARTIN GARDNER MATHEMATICAL LIBRARY Editorial Board Donald J. Albers, Menlo College Gerald L. Alexanderson, Santa Clara University John H. Conway, F.R. S., Princeton University Richard K. Guy, University of Calgary Harold R. Jacobs Donald E. Knuth, Stanford University Peter L. Renz From 1957 through 1986 Martin Gardner wrote the “Mathematical Games” columns for Scientific American that are the basis for these books. Scientific American editor Dennis Flanagan noted that this column contributed substantially to the success of the magazine. The exchanges between Martin Gardner and his readers gave life to these columns and books. These exchanges have continued and the impact of the columns and books has grown. These new editions give Martin Gardner the chance to bring readers up to date on newer twists on old puzzles and games, on new explanations and proofs, and on links to recent developments and discoveries. -
A Survey of Folding and Unfolding in Computational Geometry
Combinatorial and Computational Geometry MSRI Publications Volume 52, 2005 A Survey of Folding and Unfolding in Computational Geometry ERIK D. DEMAINE AND JOSEPH O’ROURKE Abstract. We survey results in a recent branch of computational geome- try: folding and unfolding of linkages, paper, and polyhedra. Contents 1. Introduction 168 2. Linkages 168 2.1. Definitions and fundamental questions 168 2.2. Fundamental questions in 2D 171 2.3. Fundamental questions in 3D 175 2.4. Fundamental questions in 4D and higher dimensions 181 2.5. Protein folding 181 3. Paper 183 3.1. Categorization 184 3.2. Origami design 185 3.3. Origami foldability 189 3.4. Flattening polyhedra 191 4. Polyhedra 193 4.1. Unfolding polyhedra 193 4.2. Folding polygons into convex polyhedra 196 4.3. Folding nets into nonconvex polyhedra 199 4.4. Continuously folding polyhedra 200 5. Conclusion and Higher Dimensions 201 Acknowledgements 202 References 202 Demaine was supported by NSF CAREER award CCF-0347776. O’Rourke was supported by NSF Distinguished Teaching Scholars award DUE-0123154. 167 168 ERIKD.DEMAINEANDJOSEPHO’ROURKE 1. Introduction Folding and unfolding problems have been implicit since Albrecht D¨urer [1525], but have not been studied extensively in the mathematical literature until re- cently. Over the past few years, there has been a surge of interest in these problems in discrete and computational geometry. This paper gives a brief sur- vey of most of the work in this area. Related, shorter surveys are [Connelly and Demaine 2004; Demaine 2001; Demaine and Demaine 2002; O’Rourke 2000]. We are currently preparing a monograph on the topic [Demaine and O’Rourke ≥ 2005]. -
Arxiv:2105.14305V1 [Cs.CG] 29 May 2021
Efficient Folding Algorithms for Regular Polyhedra ∗ Tonan Kamata1 Akira Kadoguchi2 Takashi Horiyama3 Ryuhei Uehara1 1 School of Information Science, Japan Advanced Institute of Science and Technology (JAIST), Ishikawa, Japan fkamata,[email protected] 2 Intelligent Vision & Image Systems (IVIS), Tokyo, Japan [email protected] 3 Faculty of Information Science and Technology, Hokkaido University, Hokkaido, Japan [email protected] Abstract We investigate the folding problem that asks if a polygon P can be folded to a polyhedron Q for given P and Q. Recently, an efficient algorithm for this problem has been developed when Q is a box. We extend this idea to regular polyhedra, also known as Platonic solids. The basic idea of our algorithms is common, which is called stamping. However, the computational complexities of them are different depending on their geometric properties. We developed four algorithms for the problem as follows. (1) An algorithm for a regular tetrahedron, which can be extended to a tetramonohedron. (2) An algorithm for a regular hexahedron (or a cube), which is much efficient than the previously known one. (3) An algorithm for a general deltahedron, which contains the cases that Q is a regular octahedron or a regular icosahedron. (4) An algorithm for a regular dodecahedron. Combining these algorithms, we can conclude that the folding problem can be solved pseudo-polynomial time when Q is a regular polyhedron and other related solid. Keywords: Computational origami folding problem pseudo-polynomial time algorithm regular poly- hedron (Platonic solids) stamping 1 Introduction In 1525, the German painter Albrecht D¨urerpublished his masterwork on geometry [5], whose title translates as \On Teaching Measurement with a Compass and Straightedge for lines, planes, and whole bodies." In the book, he presented each polyhedron by drawing a net, which is an unfolding of the surface of the polyhedron to a planar layout without overlapping by cutting along its edges. -
The Miura-Ori Opened out Like a Fan INTERNATIONAL SOCIETY for the INTERDISCIPLINARY STUDY of SYMMETRY (ISIS-SYMMETRY)
The Quarterly of the Editors: International Society for the GyiSrgy Darvas and D~nes Nag¥ interdisciplinary Study of Symmetry (ISIS-Symmetry) Volume 5, Number 2, 1994 The Miura-ori opened out like a fan INTERNATIONAL SOCIETY FOR THE INTERDISCIPLINARY STUDY OF SYMMETRY (ISIS-SYMMETRY) President ASIA D~nes Nagy, lnslltute of Apphed Physics, University of China. t~R. Da-Fu Ding, Shangha~ Institute of Biochemistry. Tsukuba, Tsukuba Soence C~ty 305, Japan Academia Stoma, 320 Yue-Yang Road, (on leave from Eotvos Lot’find Umve~ty, Budapest, Hungary) Shanghai 200031, PR China IGeometry and Crystallography, H~story of Science and [Theoreucal B~ology] Tecbnology, Lmgmsucs] Le~Xiao Yu, Department of Fine Arts. Nanjmg Normal Umvers~ty, Nanjmg 210024, P.R China Honorary Presidents }Free Art, Folk Art, Calhgraphy] Konstantin V. Frolov (Moscow) and lndta. Kirti Trivedi, Industrial Design Cenlre, lndmn Maval Ne’eman (TeI-Avw) Institute of Technology, Powa~, Bombay 400076, India lDes~gn, lndmn Art] Vice-President Israel. Hanan Bruen, School of Education, Arthur L. Loeb, Carpenter Center for the V~sual Arts, Umvers~ty of Hallo, Mount Carmel, Haffa 31999, Israel Harvard Umverslty. Cambridge, MA 02138, [Educanon] U S A. [Crystallography, Chemical Physics, Visual Art~, Jim Rosen, School of Physics and Astronomy, Choreography, Music} TeI-Av~v Umvers~ty, Ramat-Avtv, Tel-Av~v 69978. Israel and [Theoretical Physms] Sergei V Petukhov, Instnut mashmovedemya RAN (Mechamcal Engineering Research Institute, Russian, Japan. Yasushi Kajfl~awa, Synergel~cs Institute. Academy of Scmnces 101830 Moskva, ul Griboedova 4, Russia (also Head of the Russian Branch Office of the Society) 206 Nakammurahara, Odawara 256, Japan }Design, Geometry] }B~omechanlcs, B~ontcs, Informauon Mechamcs] Koichtro Mat~uno, Department of BioEngineering. -
Universal Folding Pathways of Polyhedron Nets
Universal folding pathways of polyhedron nets Paul M. Dodda, Pablo F. Damascenob, and Sharon C. Glotzera,b,c,d,1 aChemical Engineering Department, University of Michigan, Ann Arbor, MI 48109; bApplied Physics Program, University of Michigan, Ann Arbor, MI 48109; cDepartment of Materials Science and Engineering, University of Michigan, Ann Arbor, MI 48109; and dBiointerfaces Institute, University of Michigan, Ann Arbor, MI 48109 Contributed by Sharon C. Glotzer, June 6, 2018 (sent for review January 17, 2018; reviewed by Nuno Araujo and Andrew L. Ferguson) Low-dimensional objects such as molecular strands, ladders, and navigate, thermodynamically, from a denatured (unfolded) state sheets have intrinsic features that affect their propensity to fold to a natured (folded) one. Even after many decades of study, into 3D objects. Understanding this relationship remains a chal- however, a universal relationship between molecular sequence lenge for de novo design of functional structures. Using molecular and folded state—which could provide crucial insight into the dynamics simulations, we investigate the refolding of the 24 causes and potential treatments of many diseases—remains out possible 2D unfoldings (“nets”) of the three simplest Platonic of reach (11–13). shapes and demonstrate that attributes of a net’s topology— In this work, we study the thermodynamic foldability of 2D net compactness and leaves on the cutting graph—correlate nets for all five Platonic solids. Despite being the simplest and with thermodynamic folding propensity. To -
Mathematical Theory of Big Game Hunting
DOCUMEWT RESUME ED 121 522 SE 020 770 AUTHOR Schaaf, Willie' L. TITLE A Bibliography of Recreational Mathematics, Volume 1. Fourth, Edition. INSTITUTION National Council of Teachers of Mathematics, Inc., Reston, Va. PUB DATE 70 NOTE 160p.; For related documents see Ed 040 874 and ED 087 631 AVAILABLE FROMNational Council of Teachers of Mathematics, Inc., 1906 Association Drive, Reston, Virginia 22091 EDRS PRICE MP-$0.83 Plus Postage. HC Not Available from EDRS. DESCRIPTORS *Annotated Bibliographies; *Games; Geometric Concepts; History; *Literature Guides; *Mathematical Enrichment; Mathematics; *Mathematics Education; Number Concepts; Reference Books ABSTRACT This book is a partially annotated bibliography of books, articles, and periodicals concerned with mathematical games, puzzles, and amusements. It is a reprinting of Volume 1 of a three-volume series. This volume, originally published in 1955, treats problems and recreations which have been important in the history of mathematics as well as some of more modern invention. The book is intended for use by both professional and amateur mathematicians. Works on recreational mathematics are listed in eight broad categories: general works, arithmetic and algebraic recreations, geometric recreations, assorted recreations, magic squares, the Pythagorean relationship, famous problems of antiquity, and aathematical 'miscellanies. (SD) *********************************************************************** Documents acquired by ERIC include many informal unpublished * materials not available from other sources. ERIC sakes every effort * * to obtain the best copy available. Nevertheless, items of marginal * * reproducibility are often encountered and this affects the quality* * of the microfiche and hardcopy reproductions ERIC aakes available * * via the ERIC Document Reproduction Service (EDRS). EDRS is not * responsible for the quality of the original document. -
Marvelous Modular Origami
www.ATIBOOK.ir Marvelous Modular Origami www.ATIBOOK.ir Mukerji_book.indd 1 8/13/2010 4:44:46 PM Jasmine Dodecahedron 1 (top) and 3 (bottom). (See pages 50 and 54.) www.ATIBOOK.ir Mukerji_book.indd 2 8/13/2010 4:44:49 PM Marvelous Modular Origami Meenakshi Mukerji A K Peters, Ltd. Natick, Massachusetts www.ATIBOOK.ir Mukerji_book.indd 3 8/13/2010 4:44:49 PM Editorial, Sales, and Customer Service Office A K Peters, Ltd. 5 Commonwealth Road, Suite 2C Natick, MA 01760 www.akpeters.com Copyright © 2007 by A K Peters, Ltd. All rights reserved. No part of the material protected by this copyright notice may be reproduced or utilized in any form, electronic or mechanical, including photo- copying, recording, or by any information storage and retrieval system, without written permission from the copyright owner. Library of Congress Cataloging-in-Publication Data Mukerji, Meenakshi, 1962– Marvelous modular origami / Meenakshi Mukerji. p. cm. Includes bibliographical references. ISBN 978-1-56881-316-5 (alk. paper) 1. Origami. I. Title. TT870.M82 2007 736΄.982--dc22 2006052457 ISBN-10 1-56881-316-3 Cover Photographs Front cover: Poinsettia Floral Ball. Back cover: Poinsettia Floral Ball (top) and Cosmos Ball Variation (bottom). Printed in India 14 13 12 11 10 10 9 8 7 6 5 4 3 2 www.ATIBOOK.ir Mukerji_book.indd 4 8/13/2010 4:44:50 PM To all who inspired me and to my parents www.ATIBOOK.ir Mukerji_book.indd 5 8/13/2010 4:44:50 PM www.ATIBOOK.ir Contents Preface ix Acknowledgments x Photo Credits x Platonic & Archimedean Solids xi Origami Basics xii -
Exploring Mathematics
ii A Teacher’s Guide to Exploring Mathematics Ames Bryant Kit Pavlekovsky Emily Turner Tessa Whalen-Wagner Adviser: Deanna Haunsperger ii Contents Contents I Introduction V I Number Sense 1 Counting Basics 3 Grocery Shopping 4 Units 5 Modular Arithmetic 6 Logarithms and Exponents 8 Changing Bases 11 II Geometry 15 Construction I 17 Construction II 21 Möbius Strips 22 Pythagorean Theorem 23 How Far Can a Robot Reach? 25 Spherical Geometry 27 I II CONTENTS III Sets 29 De Morgan’s Law 31 Building Sets 32 Subsets 34 Investigating Infinity 36 IV Probability 39 Probability vs. Reality 41 Game Theory 43 Continuous Probability 45 Bayes’ Theorem 45 V Patterns 51 Math in Nature 53 Fibonacci in Nature 53 Counting Patterns 55 Tiling 57 VI Data 61 Bad Graphs 63 Graphs 64 Introduction to Statistics 66 CONTENTS III VII Logic 71 Pigeonhole Principle 73 Formal Logic 74 Logical Paradoxes 76 Logic Puzzles 77 VIII Miscellaneous 85 Map Coloring 87 Shortest Path Problem 88 Flexagons 90 Math in Literature 92 IV CONTENTS Introduction V VI Part I Number Sense 1 Number Sense Counting Basics Goals Learn basic skills for counting possible choices, estimating number of possible outcomes Supplies N/A Prior Knowledge N/A 9. How many ways are there for the word "light?" How many ways can you rearrange the word "happy" and end up with "happy"? 10. Think about using the shepherd’s principle. The sheep are the number of circular arrange- ments, and their legs seem to be linear arrangements of the same number of people. How many legs on each sheep? 11. -
Extending Bricard Octahedra
Extending Bricard Octahedra Gerald D. Nelson [email protected] Abstract We demonstrate the construction of several families of flexible polyhedra by extending Bricard octahedra to form larger composite flexible polyhedra. These flexible polyhedra are of genus 0 and 1, have dihedral angles that are non-constant under flexion, exhibit self- intersections and are of indefinite size, the smallest of which is a decahedron with seven vertexes. 1. Introduction Flexible polyhedra can change in spatial shape while their edge lengths and face angles remain invariant. The first examples of such polyhedra were octahedra discovered by Bricard [1] in 1897. These polyhedra, commonly known as Bricard octahedra, are of three types, have triangular faces and six vertexes and have self-intersecting faces. Over the past century they have provided the basis for numerous investigations and many papers based in total or part on the subject have been published. An early paper published in 1912 by Bennett [2] investigated the kinematics of these octahedra and showed that a prismatic flexible polyhedra (polyhedra that have parallel edges and are quadrilateral in cross section) could be derived from Bricard octahedra of the first type. Lebesgue lectured on the subject in 1938 [3]. The relationship between flexible prismatic polyhedra and Bricard octahedra was described in more detail in 1943 by Goldberg [4]. The well known counter-example to the polyhedra rigidity conjecture [5] was constructed by Connelly in 1977 using elements of Bricard octahedra to provide flexibility. A 1990 study [6] by Bushmelev and Sabitov described the configuration space of octahedra in general and of Bricard octahedra specifically. -
Anne Ray Advanced Math Project
Anne Ray ‘Horizontal Enrichment: Avoiding the “Why Do I Have to do More Work?” Question’ International School of Islamabad Islamabad, Pakistan. [email protected] Advanced Math Project STEP ONE……… 1st, begin by deciding what kind of project you wish to do. Some possibilities include: PEOPLE of MATH Study a famous mathematician and strive to understand both what he or she discovered and why it is important. The math department has biographical “starter packets.” PLACES of MATH Investigating mathematics is done differently part in some other region of the world or how the focus of mathematics might be different from the focus of math with which you are familiar. The library has a few books on the math of other regions and there is a lot of information on the web. Also, there is a book titled Math Elsewhere that you might be able to find. IDEAS of Math Consider some major concept of math, such as: zero, or coordinate graphing, or the Golden Ratio or pi, or logarithms, or the use of unknowns; and try to follow the history of this concept back in time and understand how it evolved and why it became important to the future progress of math. This is a research project, that can be pursued both on the internet and in popular math literature. CONNECTIONS to Math Investigate how math relates to some other field of interest, such as art, music, or sports. Design a project that will help you better understand the connection between mathematic and some other interest of yours, and help you gain the skills necessary to become more proficient at both.