25 research outputs found

    The further chameleon groups of Richard Thompson and Graham Higman : automorphisms via dynamics for the Higman groups Gn,r

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    Funding: The first and second authors wish to acknowledge support from EPSRC grant EP/R032866/1 received during the editing process of this article. The fourth author would like to thank St. Andrews University for its hospitality during the Workshop on the Extended Family of Thompson’s Groups in 2014, and acknowledges the support of DySYRF (Anillo Project 1103, CONICYT) and Fondecyt’s project 1120131. The fifth author was partly supported by Leverhulme Trust Research Project Grant RPG-2017-159.We characterise the automorphism groups of the Higman groups Gn,r as groups of specific homeomorphisms of Cantor spaces Cn,r, through the use of Rubin's theorem. This continues a thread of research begun by Brin, and extended later by Brin and Guzmán: to characterise the automorphism groups of the 'Chameleon groups of Richard Thompson,' as Brin referred to them in 1996. The work here completes the first stage of that twenty-year-old program, containing (amongst other things) a characterisation of the automorphism group of V, which was the 'last chameleon.' As it happens, the homeomorphisms which arise naturally fit into the framework of Grigorchuk, Nekrashevich, and Suschanskiī's rational group of transducers, and exhibit fascinating connections with the theory of reset words for automata (arising in the Road Colouring Problem), while also appearing to offer insight into the nature of Brin and Guzmán's exotic automorphisms.PostprintPeer reviewe

    All things being equal: uncertainty, ambivalence and trust in a Namibian conservancy

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    This thesis is about how experiences of uncertainty shape the way people share with one another. It is an ethnographic study of a rural conservancy in north-eastern Namibia, the Nyae Nyae Conservancy, and the urban town at its centre, Tsumkwe—between which people “roam in order to live”. The people at the centre of this study are the Ju|’hoansi (meaning “true people” or “people of proper custom”), known to anthropology both as hunter-gatherers and as a famously “egalitarian society”. In Namibia, they are a “traditional community” with ancestral rights to a communal land region that they now manage largely as a commercial enterprise. In doing so, they aim to perform the complementary work of conserving their ancestral way of life and the diverse fauna and flora they share it with, and enticing tourists, entrepreneurs, and trophy-hunters to provide the cash now necessary to do so. This work only goes so far in making people self-sufficient, however, giving rise to a regular push and pull between their territories and town. These movements reflect broader shifts towards informality, precariousness, and rising inequality across southern Africa, but they are also extensions of a much longer history of “roaming” that has been the subject of extensive writing within the discipline on hunter-gatherers and their fiercely egalitarian values. This writing sees roaming as a practice circumscribed by the assumption that those who have more than they can immediately use or consume will give in to the demands of roaming others without expecting repayment. In its contemporary guise, however, roaming necessitates encounters not with “true people”, like themselves, whom they expect will share without hesitation, but with “other people” who “want to refuse you”, “want to ruin you”, or who “cannot be trusted”. This thesis takes this nexus—between the values ordinarily associated with egalitarianism and the contemporary social context—as a productive space within which to explore the way that people go about sharing in the face of uncertainty and negotiating the ambivalence that emerges in the process. This thesis is based on ethnographic fieldwork carried out in the Nyae Nyae conservancy between October 2014 – December 2015. It contributes to current debates within the anthropology of value on redistributive regimes and within the anthropology of ethics on experiences of moral ambivalence, and to broader fields of research on the relationship between state processes and informal economies in southern Africa

    Bootstrapping Hypotheses Tests

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    Transitivity in Bakel Soninke

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    Dans cet article, après avoir présenté les principales particularités du soninké de Bakel dans le domaine de la phonologie et de la morphosyntaxe, nous examinons de façon détaillée les mécanismes morphosyntaxiques liés à la transitivité : alternances de transitivité non marquées morphologiquement et dérivations exprimant une opération sur la valence verbale. Dans ce domaine, les caractéristiques les plus saillantes du soninké sont une dérivation antipassive productive allant de pair avec la rareté des verbes A-labiles, et un phénomène de P-labilité concernant presque exclusivement les lexèmes verbaux terminés par i ou e, en quasi-complémentarité avec une dérivation à fonction médiopassive propre aux verbes terminés par a, o ou u.In this paper, after presenting the main particularities of the phonology and morphosyntax of Bakel Soninke, we provide a detailed analysis of the morphosyntactic mechanisms involving transitivity: morphologically unmarked transitivity alternations and derivations expressing operations on verbal valency. In this domain, the most salient characteristics of Soninke are the combination of productive antipassive derivation and scarcity of A-labile verbs, and P-lability concerning almost exclusively verbal lexemes ending in -iand‑e, in near-complementary distribution with a mediopassive derivation found only with verbs ending in –a, -o, -u.В данной статье, после изложения базовых сведений по фонологии и морфологии сонинке р-на Бакел, даётся подробный анализ морфосинтаксического механизма переходности: морфологически немаркированная вариативность и валентностные деривации. Наиболее заметные в этом отношении особенности сонинке представлены продуктивной антипассивной деривацией, а также редкостью А-лабильных глаголов. Интересно также, что Р-лабильность затрагивает почти исключительно глагольные лексемы с исходом на –i и –e, оказываясь таким образом почти в дополнительной дистрибуции с медиопассивной деривацией, характерной для глаголов с исходом на –a, -o, -u

    State v. Lemmons Clerk\u27s Record Dckt. 41278

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    https://digitalcommons.law.uidaho.edu/not_reported/2560/thumbnail.jp

    XHaskell - Adding regular expression types to haskell

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    Ph.DDOCTOR OF PHILOSOPH

    Verfahren zur Verarbeitung von XML-Werten in SQL-Anfrageergebnissen

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    Gemäß der aktuellen Version der SQL-Norm kann ein Anfrageergebnis beliebige XQuery-Sequenzen als Spaltenwerte enthalten. Dies schließt insbesondere auch aus mehreren Sequenzeinträgen bestehende XQuery-Sequenzen ein, deren Knoten mit Typinformationen angereichert sind. Auf die Frage, wie sich derartige (in einem SQL-Anfrageergebnis enthaltene) XQuery-Sequenzen adäquat mit Hilfe eines Anwendungsprogramms verarbeiten lassen, liefert bisher allerdings weder die SQL-Norm noch ein RDBMS-Produkt eine zufriedenstellende Antwort. Zum Schließen dieser Lücke wird in der vorliegenden Arbeit das Verfahren der Sequenzcursor-basierten Verarbeitung eingeführt. Die Grundidee dieses Verfahrens (welches eine angemessene und komfortable Verarbeitung der in einem SQL-Anfrageergebnis enthaltenen XQuery-Sequenzen ermöglicht) besteht darin, mit Hilfe einer neuen Cursorart, den so genannten Sequenzcursorn, in die XQuery-Sequenzen des aktuellen Ergebnistupels einzutauchen, um Sequenzausschnitte zu definieren. Diese Sequenzausschnitte werden dann ins Anwendungsprogramm übertragen und dort lokal verarbeitet. Sofern dabei Änderungen an den Sequenzausschnitten vorgenommen werden, kann das Anwendungsprogramm entscheiden, ob diese Änderungen in die Datenbank (wieder)eingebracht werden sollen

    Adaptive anwendungsspezifische Verarbeitung von XML-Dokumenten

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    In dieser Arbeit wird ein Konzept vorgeschlagen, mit dem neue hohere Operatoren auf der Grundlage existierender Operatoren einer XML-Transformationsprache aufgebaut werden können. Durch das Zusammenfassen von immer wieder auftretenden Operatorkombinationen zu höheren Operatoren können Transformationsdefinitionen bspw. kürzer und verständlicher beschrieben werden. Zur Umsetzung des Konzeptes ist die Ausführungsumgebung XTC entstanden. XTC koordiniert den Ablauf, um höhere Operatoren in niedrigere, letztendlich elementare Operatoren einer Basistransformationssprache zu überführen. Neben XTC wird das Generatorsystem XOpGen entwickelt, welches den Implementierungsaufwand für die neuen höheren Operatoren weiter verringert. Das Potential von höheren Operatoren wird an der vom W3C standardisierten XML-Transformationssprache XSLT demonstriert. XSLT wird mit verschiedenen, sowohl universellen als auch domänenspezifischen, Operatoren erweitert

    Scalable XQuery type matching

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    XML Schema awareness has been an integral part of the XQuery language since its early design stages. Matching XML data against XML types is the main operation that backs up XQuery type expressions, such as typeswitch, instance of, or certain XPath operators. This interaction is particularly vital in data-centric XQuery applications, where data come with detailed type information from an XML Schema document. So far there has been little work on the optimization of those operations. This work presents an efficient implementation of the runtime aspects of XML Schema support. We propose type ranks as a novel and uniform way to implement all facets of type matching in the W3C XQuery Recommendation. As a concise encoding of the type hierarchy defined by an XML Schema document, type ranks minimize the cost of checking the runtime type of XQuery singleton items. By aggregating type ranks, we leverage the grouping capabilities of modern DBMS implementations to efficiently execute type matching on XQuery sequences. In addition, we improve the complexity bounds incurring with typeswitch expressions over existing approaches. Experiments on an off-the-shelf database system demonstrate the potential of our approach
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