Letöltés (13MB)
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Eminescu and the Transition to Peak-Ring Basins on Mercury
41st Lunar and Planetary Science Conference (2010) 1263.pdf EMINESCU AND THE TRANSITION TO PEAK-RING BASINS ON MERCURY. S. C. Schon,1 J. W. Head,1 L. M. Prockter2, and the MESSENGER Science Team.3 1Dept. of Geological Sciences, Brown University, Providence, RI 02906 USA; 2JHU/APL, Laurel, MD; 3http://messenger.jhuapl.edu/who_we_are/science_team.html. Introduction: The MESSENGER [1] flybys have yielded a range of new scientific findings for Mercury [2] including evidence of embayment relationships indicative of volcanic plains activity [3,4] and an im- proved size estimate for the Caloris basin [5]. These new data reveal a broad continuum of Mercurian crater morphologies [6] in greater detail than prior studies that relied on Mariner 10 or Earth-based radar observa- tions [7]. This study focuses on mapping the interior deposits of Eminescu, a central peak-ring basin, and is part of a larger comparative analysis of transitional crater morphologies observed on Mercury and the Moon in new data sets [8]. Impacts on Mercury occur at much higher veloci- ties than lunar impacts and correspondingly generate more impact melt. Cintala [9] estimated that for a given projectile, the velocity difference will lead to twice as much impact melt on Mercury than on the Moon. Here we examine images at ~150 m/pixel reso- Figure 1: Eminescu Crater, ~125-km in diameter (10.8°N, lution of the fresh impact crater Eminescu to document 114.1°E), imaged during the first MESSENGER flyby. the nature of fresh crater interiors on Mercury at the transition from complex to peak-ring morphology. -
Classes of Semigroups Modulo Green's Relation H
Classes of semigroups modulo Green’s relation H Xavier Mary To cite this version: Xavier Mary. Classes of semigroups modulo Green’s relation H. Semigroup Forum, Springer Verlag, 2014, 88 (3), pp.647-669. 10.1007/s00233-013-9557-9. hal-00679837 HAL Id: hal-00679837 https://hal.archives-ouvertes.fr/hal-00679837 Submitted on 16 Mar 2012 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Classes of semigroups modulo Green’s relation H Xavier Mary∗ Universit´eParis-Ouest Nanterre-La D´efense, Laboratoire Modal’X Keywords generalized inverses; Green’s relations; semigroups 2010 MSC: 15A09, 20M18 Abstract Inverses semigroups and orthodox semigroups are either defined in terms of inverses, or in terms of the set of idempotents E(S). In this article, we study analogs of these semigroups defined in terms of inverses modulo Green’s relation H, or in terms of the set of group invertible elements H(S), that allows a study of non-regular semigroups. We then study the interplays between these new classes of semigroups, as well as with known classes of semigroups (notably inverse, orthodox and cryptic semigroups). 1 Introduction The study of special classes of semigroups relies in many cases on properties of the set of idempo- tents, or of regular pairs of elements. -
Mercury's Low-Reflectance Material: Constraints from Hollows
Mercury’s low-reflectance material: Constraints from hollows Rebecca Thomas, Brian Hynek, David Rothery, Susan Conway To cite this version: Rebecca Thomas, Brian Hynek, David Rothery, Susan Conway. Mercury’s low-reflectance material: Constraints from hollows. Icarus, Elsevier, 2016, 277, pp.455-465. 10.1016/j.icarus.2016.05.036. hal-02271739 HAL Id: hal-02271739 https://hal.archives-ouvertes.fr/hal-02271739 Submitted on 27 Aug 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Accepted Manuscript Mercury’s Low-Reflectance Material: Constraints from Hollows Rebecca J. Thomas , Brian M. Hynek , David A. Rothery , Susan J. Conway PII: S0019-1035(16)30246-9 DOI: 10.1016/j.icarus.2016.05.036 Reference: YICAR 12084 To appear in: Icarus Received date: 23 February 2016 Revised date: 9 May 2016 Accepted date: 24 May 2016 Please cite this article as: Rebecca J. Thomas , Brian M. Hynek , David A. Rothery , Susan J. Conway , Mercury’s Low-Reflectance Material: Constraints from Hollows, Icarus (2016), doi: 10.1016/j.icarus.2016.05.036 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. -
3. Inverse Semigroups
3. INVERSE SEMIGROUPS MARK V. LAWSON 1. Introduction Inverse semigroups were introduced in the 1950s by Ehresmann in France, Pre- ston in the UK and Wagner in the Soviet Union as algebraic analogues of pseu- dogroups of transformations. One of the goals of this article is to give some insight into inverse semigroups by showing that they can in fact be seen as extensions of presheaves of groups by pseudogroups of transformations. Inverse semigroups can be viewed as generalizations of groups. Group theory is based on the notion of a symmetry; that is, a structure-preserving bijection. Un- derlying group theory is therefore the notion of a bijection. The set of all bijections from a set X to itself forms a group, S(X), under composition of functions called the symmetric group. Cayley's theorem tells us that each abstract group is isomor- phic to a subgroup of a symmetric group. Inverse semigroup theory, on the other hand, is based on the notion of a partial symmetry; that is, a structure-preserving partial bijection. Underlying inverse semigroup theory, therefore, is the notion of a partial bijection (or partial permutation). The set of all partial bijections from X to itself forms a semigroup, I(X), under composition of partial functions called the symmetric inverse monoid. The Wagner-Preston representation theorem tells us that each abstract inverse semigroup is isomorphic to an inverse subsemigroup of a symmetric inverse monoid. However, symmetric inverse monoids and, by extension, inverse semigroups in general, are endowed with extra structure, as we shall see. The first version of this article was prepared for the Workshop on semigroups and categories held at the University of Ottawa between 2nd and 4th May 2010. -
Impact Melt Emplacement on Mercury
Western University Scholarship@Western Electronic Thesis and Dissertation Repository 7-24-2018 2:00 PM Impact Melt Emplacement on Mercury Jeffrey Daniels The University of Western Ontario Supervisor Neish, Catherine D. The University of Western Ontario Graduate Program in Geology A thesis submitted in partial fulfillment of the equirr ements for the degree in Master of Science © Jeffrey Daniels 2018 Follow this and additional works at: https://ir.lib.uwo.ca/etd Part of the Geology Commons, Physical Processes Commons, and the The Sun and the Solar System Commons Recommended Citation Daniels, Jeffrey, "Impact Melt Emplacement on Mercury" (2018). Electronic Thesis and Dissertation Repository. 5657. https://ir.lib.uwo.ca/etd/5657 This Dissertation/Thesis is brought to you for free and open access by Scholarship@Western. It has been accepted for inclusion in Electronic Thesis and Dissertation Repository by an authorized administrator of Scholarship@Western. For more information, please contact [email protected]. Abstract Impact cratering is an abrupt, spectacular process that occurs on any world with a solid surface. On Earth, these craters are easily eroded or destroyed through endogenic processes. The Moon and Mercury, however, lack a significant atmosphere, meaning craters on these worlds remain intact longer, geologically. In this thesis, remote-sensing techniques were used to investigate impact melt emplacement about Mercury’s fresh, complex craters. For complex lunar craters, impact melt is preferentially ejected from the lowest rim elevation, implying topographic control. On Venus, impact melt is preferentially ejected downrange from the impact site, implying impactor-direction control. Mercury, despite its heavily-cratered surface, trends more like Venus than like the Moon. -
Geologic Map of the Victoria Quadrangle (H02), Mercury
H01 - Borealis Geologic Map of the Victoria Quadrangle (H02), Mercury 60° Geologic Units Borea 65° Smooth plains material 1 1 2 3 4 1,5 sp H05 - Hokusai H04 - Raditladi H03 - Shakespeare H02 - Victoria Smooth and sparsely cratered planar surfaces confined to pools found within crater materials. Galluzzi V. , Guzzetta L. , Ferranti L. , Di Achille G. , Rothery D. A. , Palumbo P. 30° Apollonia Liguria Caduceata Aurora Smooth plains material–northern spn Smooth and sparsely cratered planar surfaces confined to the high-northern latitudes. 1 INAF, Istituto di Astrofisica e Planetologia Spaziali, Rome, Italy; 22.5° Intermediate plains material 2 H10 - Derain H09 - Eminescu H08 - Tolstoj H07 - Beethoven H06 - Kuiper imp DiSTAR, Università degli Studi di Napoli "Federico II", Naples, Italy; 0° Pieria Solitudo Criophori Phoethontas Solitudo Lycaonis Tricrena Smooth undulating to planar surfaces, more densely cratered than the smooth plains. 3 INAF, Osservatorio Astronomico di Teramo, Teramo, Italy; -22.5° Intercrater plains material 4 72° 144° 216° 288° icp 2 Department of Physical Sciences, The Open University, Milton Keynes, UK; ° Rough or gently rolling, densely cratered surfaces, encompassing also distal crater materials. 70 60 H14 - Debussy H13 - Neruda H12 - Michelangelo H11 - Discovery ° 5 3 270° 300° 330° 0° 30° spn Dipartimento di Scienze e Tecnologie, Università degli Studi di Napoli "Parthenope", Naples, Italy. Cyllene Solitudo Persephones Solitudo Promethei Solitudo Hermae -30° Trismegisti -65° 90° 270° Crater Materials icp H15 - Bach Australia Crater material–well preserved cfs -60° c3 180° Fresh craters with a sharp rim, textured ejecta blanket and pristine or sparsely cratered floor. 2 1:3,000,000 ° c2 80° 350 Crater material–degraded c2 spn M c3 Degraded craters with a subdued rim and a moderately cratered smooth to hummocky floor. -
CERTAIN FUNDAMENTAL CONGRUENCES on a REGULAR SEMIGROUP! by J
CERTAIN FUNDAMENTAL CONGRUENCES ON A REGULAR SEMIGROUP! by J. M. HOWIE and G. LALLEMENT (Received 21 June, 1965) In recent developments in the algebraic theory of semigroups attention has been focussing increasingly on the study of congruences, in particular on lattice-theoretic properties of the lattice of congruences. In most cases it has been found advantageous to impose some re- striction on the type of semigroup considered, such as regularity, commutativity, or the property of being an inverse semigroup, and one of the principal tools has been the consideration of special congruences. For example, the minimum group congruence on an inverse semigroup has been studied by Vagner [21] and Munn [13], the maximum idempotent-separating con- gruence on a regular or inverse semigroup by the authors separately [9, 10] and by Munn [14], and the minimum semilattice congruence on a general or commutative semigroup by Tamura and Kimura [19], Yamada [22], Clifford [3] and Petrich [15]. In this paper we study regular semigroups and our primary concern is with the minimum group congruence, the minimum band congruence and the minimum semilattice congruence, which we shall con- sistently denote by a, P and t] respectively. In § 1 we establish connections between /? and t\ on the one hand and the equivalence relations of Green [7] (see also Clifford and Preston [4, § 2.1]) on the other. If for any relation H on a semigroup S we denote by K* the congruence on S generated by H, then, in the usual notation, In § 2 we show that the intersection of a with jS is the smallest congruence p on S for which Sip is a UBG-semigroup, that is, a band of groups [4, p. -
Green's Relations and Dimension in Abstract Semi-Groups
University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 8-1964 Green's Relations and Dimension in Abstract Semi-groups George F. Hampton University of Tennessee - Knoxville Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Mathematics Commons Recommended Citation Hampton, George F., "Green's Relations and Dimension in Abstract Semi-groups. " PhD diss., University of Tennessee, 1964. https://trace.tennessee.edu/utk_graddiss/3235 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by George F. Hampton entitled "Green's Relations and Dimension in Abstract Semi-groups." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the requirements for the degree of Doctor of Philosophy, with a major in Mathematics. Don D. Miller, Major Professor We have read this dissertation and recommend its acceptance: Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) July 13, 1962 To the Graduate Council: I am submitting herewith a dissertation written by George Fo Hampton entitled "Green's Relations and Dimension in Abstract Semi groups.-" I recommend that it be accepted in partial fulfillment of the requirements for the degree of Doctor of Philosop�y, with a major in Mathematics. -
Von Neumann Regular Cellular Automata
Von Neumann Regular Cellular Automata Alonso Castillo-Ramirez and Maximilien Gadouleau May 29, 2017 Abstract For any group G and any set A, a cellular automaton (CA) is a transformation of the configuration space AG defined via a finite memory set and a local function. Let CA(G; A) be the monoid of all CA over AG. In this paper, we investigate a generalisation of the inverse of a CA from the semigroup-theoretic perspective. An element τ ∈ CA(G; A) is von Neumann regular (or simply regular) if there exists σ ∈ CA(G; A) such that τ ◦ σ ◦ τ = τ and σ ◦ τ ◦ σ = σ, where ◦ is the composition of functions. Such an element σ is called a generalised inverse of τ. The monoid CA(G; A) itself is regular if all its elements are regular. We establish that CA(G; A) is regular if and only if |G| = 1 or |A| = 1, and we characterise all regular elements in CA(G; A) when G and A are both finite. Furthermore, we study regular linear CA when A = V is a vector space over a field F; in particular, we show that every regular linear CA is invertible when G is torsion-free elementary amenable (e.g. when G = Zd, d ∈ N) and V = F, and that every linear CA is regular when V is finite-dimensional and G is locally finite with char(F) ∤ o(g) for all g ∈ G. Keywords: Cellular automata, linear cellular automata, monoids, von Neumann regular elements, generalised inverses. 1 Introduction Cellular automata (CA), introduced by John von Neumann and Stanislaw Ulam in the 1940s, are models of computation with important applications to computer science, physics, and theoretical biology. -
UNIT-REGULAR ORTHODOX SEMIGROUPS by R
UNIT-REGULAR ORTHODOX SEMIGROUPS by R. B. McFADDEN (Received 5 May, 1983) Introduction. Unit-regular rings were introduced by Ehrlich [4]. They arose in the search for conditions on a regular ring that are weaker than the ACC, DCC, or finite Goldie dimension, which with von Neumann regularity imply semisimplicity. An account of unit-regular rings, together with a good bibliography, is given by Goodearl [5]. The basic definition of unit-regularity is purely multiplicative; it is simply that for each element x of a monoid S (initially a ring R with identity) there is a unit u of S for which x = xux. The concept of a unit-regular semigroup is a natural one; for example, the full transformation semigroup on a finite set, and the semigroup of endomorphisms of a finite-dimensional vector space, are unit-regular semigroups [1]. Unit-regularity has been studied by Chen and Hsieh [2], by Tirasupa [9], and by McAlister [6]. The connection between unit-regularity and finiteness conditions has been considered by D'Alarcao [3]. The problem of describing the structure of an arbitrary unit-regular semigroup S is difficult. It appears reasonable to attempt to provide such a description in terms of the group of units of S and the set of idempotents of S, and in this direction Blyth and McFadden did determine the structure of a narrow class of unit-regular semigroups. Calling a semigroup S uniquely unit orthodox if it is orthodox and, for each x in S, there exists a unique unit u of S for which x = xux, they proved that every such semigroup is a semidirect product of a group (the group of units of S) and a band (the band of idempotents of S). -
Back Matter (PDF)
Index Page numbers in italic denote Figures. Page numbers in bold denote Tables. ‘a’a lava 15, 82, 86 Belgica Rupes 272, 275 Ahsabkab Vallis 80, 81, 82, 83 Beta Regio, Bouguer gravity anomaly Aino Planitia 11, 14, 78, 79, 83 332, 333 Akna Montes 12, 14 Bhumidevi Corona 78, 83–87 Alba Mons 31, 111 Birt crater 378, 381 Alba Patera, flank terraces 185, 197 Blossom Rupes fold-and-thrust belt 4, 274 Albalonga Catena 435, 436–437 age dating 294–309 amors 423 crater counting 296, 297–300, 301, 302 ‘Ancient Thebit’ 377, 378, 388–389 lobate scarps 291, 292, 294–295 anemone 98, 99, 100, 101 strike-slip kinematics 275–277, 278, 284 Angkor Vallis 4,5,6 Bouguer gravity anomaly, Venus 331–332, Annefrank asteroid 427, 428, 433 333, 335 anorthosite, lunar 19–20, 129 Bransfield Rift 339 Antarctic plate 111, 117 Bransfield Strait 173, 174, 175 Aphrodite Terra simple shear zone 174, 178 Bouguer gravity anomaly 332, 333, 335 Bransfield Trough 174, 175–176 shear zones 335–336 Breksta Linea 87, 88, 89, 90 Apollinaris Mons 26,30 Brumalia Tholus 434–437 apollos 423 Arabia, mantle plumes 337, 338, 339–340, 342 calderas Arabia Terra 30 elastic reservoir models 260 arachnoids, Venus 13, 15 strike-slip tectonics 173 Aramaiti Corona 78, 79–83 Deception Island 176, 178–182 Arsia Mons 111, 118, 228 Mars 28,33 Artemis Corona 10, 11 Caloris basin 4,5,6,7,9,59 Ascraeus Mons 111, 118, 119, 205 rough ejecta 5, 59, 60,62 age determination 206 canali, Venus 82 annular graben 198, 199, 205–206, 207 Canary Islands flank terraces 185, 187, 189, 190, 197, 198, 205 lithospheric flexure -
The Unique Cultural & Innnovative Twelfty 1820
Chekhov reading The Seagull to the Moscow Art Theatre Group, Stanislavski, Olga Knipper THE UNIQUE CULTURAL & INNNOVATIVE TWELFTY 1820-1939, by JACQUES CORY 2 TABLE OF CONTENTS No. of Page INSPIRATION 5 INTRODUCTION 6 THE METHODOLOGY OF THE BOOK 8 CULTURE IN EUROPEAN LANGUAGES IN THE “CENTURY”/TWELFTY 1820-1939 14 LITERATURE 16 NOBEL PRIZES IN LITERATURE 16 CORY'S LIST OF BEST AUTHORS IN 1820-1939, WITH COMMENTS AND LISTS OF BOOKS 37 CORY'S LIST OF BEST AUTHORS IN TWELFTY 1820-1939 39 THE 3 MOST SIGNIFICANT LITERATURES – FRENCH, ENGLISH, GERMAN 39 THE 3 MORE SIGNIFICANT LITERATURES – SPANISH, RUSSIAN, ITALIAN 46 THE 10 SIGNIFICANT LITERATURES – PORTUGUESE, BRAZILIAN, DUTCH, CZECH, GREEK, POLISH, SWEDISH, NORWEGIAN, DANISH, FINNISH 50 12 OTHER EUROPEAN LITERATURES – ROMANIAN, TURKISH, HUNGARIAN, SERBIAN, CROATIAN, UKRAINIAN (20 EACH), AND IRISH GAELIC, BULGARIAN, ALBANIAN, ARMENIAN, GEORGIAN, LITHUANIAN (10 EACH) 56 TOTAL OF NOS. OF AUTHORS IN EUROPEAN LANGUAGES BY CLUSTERS 59 JEWISH LANGUAGES LITERATURES 60 LITERATURES IN NON-EUROPEAN LANGUAGES 74 CORY'S LIST OF THE BEST BOOKS IN LITERATURE IN 1860-1899 78 3 SURVEY ON THE MOST/MORE/SIGNIFICANT LITERATURE/ART/MUSIC IN THE ROMANTICISM/REALISM/MODERNISM ERAS 113 ROMANTICISM IN LITERATURE, ART AND MUSIC 113 Analysis of the Results of the Romantic Era 125 REALISM IN LITERATURE, ART AND MUSIC 128 Analysis of the Results of the Realism/Naturalism Era 150 MODERNISM IN LITERATURE, ART AND MUSIC 153 Analysis of the Results of the Modernism Era 168 Analysis of the Results of the Total Period of 1820-1939