Combined permutation codes for synchronization

Abstract: A combined code is a code that combines two or more characteristics of other codes. A construction is presented in this paper of permutation codes that are self-synchronizing and able to correct a number of deletion errors per codeword, thus a combined permutation code. Synchronization errors, modelled as deletion(s) and/or insertion(s) of bits or symbols, can be catastrophic if not detected and corrected. Some classes of codes have been proposed that are synchronizable, i.e. they can be used to regain synchronization although the error leading to the loss of synchronization is not corrected. Typically, different classes of codes are needed to correct deletion and/or insertion errors after codeword boundaries have been detected. The codebooks presented in this paper consist of codewords divided into segments. By imposing restrictions on the segments, the codewords are synchronizable. One deletion error can be detected and corrected per segment

The compressive failure of graphite/epoxy plates with circular holes

The behavior of fiber reinforced composite plates containing a circular cutout was characterized in terms of geometry (thickness, width, hole diameter), and material properties (bending/extensional stiffness). Results were incorporated in a data base for use by designers in determining the ultimate strength of such a structure. Two thicknesses, 24 plies and 48 plies were chosen to differentiate between buckling and strength failures due to the presence of a cutout. Consistent post-buckling strength was exhibited by both laminate configurations

An extensive English language bibliography on graph theory and its applications, supplement 1

Graph theory and its applications - bibliography, supplement

Verb prefixes in Latgalian : a discussion based on data found in a collection of Latgalian folk tales

Latgalian originated in the eastern part of Latvia (see Maps 1 and 2, Appendix 1 ) . Although still spoken, it is gradually becoming extinct as it is being replaced by the more prestigious official, literary, standard Latvian which in turn is being replaced in many sectors of administration by Russian; eastern Latvia has a high concentration of Russian inhabitants (see Map 3, Appendix 1). In spite of the fact that it has been and is the language of literary expression of a number of poets and writers and that it even has its own newspaper published in Munich, Latgalian outside Latvia is spoken by an ever decreasing number of exiled Latgalians. Its speakers, coming from some of the poorest areas of rural Latvia, have traditionally been labelled as mostly uneducated and uncultured and it is only comparatively recently that such labels have begun to disappear

A grammar of Papuan Malay

This book presents an in-depth linguistic description of Papuan Malay, a non-standard variety of Malay. The language is spoken in coastal West Papua which covers the western part of the island of New Guinea. The study is based on sixteen hours of recordings of spontaneous narratives and conversations between Papuan Malay speakers, recorded in the Sarmi area on the northeast coast of West Papua. Papuan Malay is the language of wider communication and the first or second language for an ever-increasing number of people of the area. While Papuan Malay is not officially recognized and therefore not used in formal government or educational settings or for religious preaching, it is used in all other domains, including unofficial use in formal settings, and, to some extent, in the public media. After a general introduction to the language, its setting, and history, this grammar discusses the following topics, building up from smaller grammatical constituents to larger ones: phonology, word formation, noun and prepositional phrases, verbal and nonverbal clauses, non-declarative clauses, and conjunctions and constituent combining. Of special interest to linguists, typologists, and Malay specialists are the following in-depth analyses and descriptions: affixation and its productivity across domains of language choice, reduplication and its gesamtbedeutung, personal pronouns and their adnominal uses, demonstratives and locatives and their extended uses, and adnominal possessive relations and their non- canonical uses. This study provides a starting point for Papuan Malay language development efforts and a point of comparison for further studies on other Malay varieties

Essays in Behavioural Economics

The goal of behavioural economics is to improve classic microeconomic theory by introducing motives and concepts from related fields like psychology and sociology. The driving paradigm of most neo-classical economic research is the concept of the Homo Oeconomicus, a human who approaches all problems in a rational and typically selfish way and who possesses boundless computational power and flawless reasoning. Despite the obvious oversimplification, the given assumptions allow the precise analysis of a large number of complex problems and have led to many interesting and often surprising findings and theories. While the value of constructing theoretical economic models is beyond doubt, it is important to be aware that the simplifying assumptions made within limit the scope of the predictions made. The assumption that perfectly reasonable people interact in a strictly logical way often leads to conclusions which bear no resemblance to real-world observations. The role of behavioural economic research is not to abandon theoretical research but to question and test the assumptions made by economic models, to identify contradictions to actual observations when they occur and to develop alternative models to capture apparent flaws in the models, or, as one might argue, flaws in human behaviour. Examples for such flaws include loss aversion1 and non-exponential discounting which, despite being irrational from a theoretical perspective, seem to be prevalent themes in human behaviour. Social preferences play a role when people interact and social norms cause them to behave in a nice way when treated well or to reciprocate and punish their counterpart even at their own expense. Furthermore humans have difficulties when dealing with complex problems, which is referred to as bounded rationality. People tend to make calculation mistakes, use rough approximations and imprecise simplifications when facing difficult problems. The first three chapters of this dissertation cover three different topics tied to behavioural economics. They connect concepts originating from psychology and sociology like intrinsic and extrinsic motivation and the so-called locus of control and apply them to microeconomic problems like the optimal effort provision in a principal-agent setting. The fourth chapter is strongly related to computer science as it describes the development of a computer system intended to simplify the design and conduction of economic experiments. While it is the project most distant to economics, it is arguably also the most ambitious of the four projects

Opening Public Transit Data in Germany

Open data has been recognized as a valuable resource, and public institutions have taken to publishing their data under open licenses, also in Germany. However, German public transit agencies are still reluctant to publish their schedules as open data. Also, two widely used data exchange formats used in German transit planning are proprietary, with no documentation publicly available. Through this work, one of the proprietary formats was reverse-engineered, and a transformation process into the open GTFS schedule format was developed. This process allowed a partnering transit operator to publish their schedule as open data. Also, through a survey taken with German transit authorities and operators, the prevalence of transit data exchange formats, and reservations concerning open transit data were evaluated. The survey brought a series of issues to light which serve as obstacles for opening up transit data. Addressing the issues found through this work, and partnering with open-minded transit authorities to further develop transit data publishing processes can serve as a foundation for wider adoption of publishing open transit data in Germany

An analysis of hinneh as a discourse marker in Genesis - 2 Kings

Please find Abstract included as a separate fil

Proof-checking mathematical texts in controlled natural language

The research conducted for this thesis has been guided by the vision of a computer program that could check the correctness of mathematical proofs written in the language found in mathematical textbooks. Given that reliable processing of unrestricted natural language input is out of the reach of current technology, we focused on the attainable goal of using a controlled natural language (a subset of a natural language defined through a formal grammar) as input language to such a program. We have developed a prototype of such a computer program, the Naproche system. This thesis is centered around the novel logical and linguistic theory needed for defining and motivating the controlled natural language and the proof checking algorithm of the Naproche system. This theory provides means for bridging the wide gap between natural and formal mathematical proofs. We explain how our system makes use of and extends existing linguistic formalisms in order to analyse the peculiarities of the language of mathematics. In this regard, we describe a phenomenon of this language previously not described by other logicians or linguists, the implicit dynamic function introduction, exemplified by constructs of the form "for every x there is an f(x) such that ...". We show how this function introduction can lead to a paradox analogous to Russell's paradox. To tackle this problem, we developed a novel foundational theory of functions called Ackermann-like Function Theory, which is equiconsistent to ZFC (Zermelo-Fraenkel set theory with the Axiom of Choice) and can be used for imposing limitations to implicit dynamic function introduction in order to avoid this paradox. We give a formal account of implicit dynamic function introduction by extending Dynamic Predicate Logic, a formalism developed by linguists to account for the dynamic nature of natural language quantification, to a novel formalism called Higher-Order Dynamic Predicate Logic, whose semantics is based on Ackermann-like Function Theory. Higher-Order Dynamic Predicate Logic also includes a formal account of the linguistic theory of presuppositions, which we use for clarifying and formally modelling the usage of potentially undefined terms (e.g. 1/x, which is undefined for x=0) and of definite descriptions (e.g. "the even prime number") in the language of mathematics. The semantics of the controlled natural language is defined through a translation from the controlled natural language into an extension of Higher-Order Dynamic Predicate Logic called Proof Text Logic. Proof Text Logic extends Higher-Order Dynamic Predicate Logic in two respects, which make it suitable for representing the content of mathematical texts: It contains features for representing complete texts rather than single assertions, and instead of being based on Ackermann-like Function Theory, it is based on a richer foundational theory called Class-Map-Tuple-Number Theory, which does not only have maps/functions, but also classes/sets, tuples, numbers and Booleans as primitives. The proof checking algorithm checks the deductive correctness of proof texts written in the controlled natural language of the Naproche system. Since the semantics of the controlled natural language is defined through a translation into the Proof Text Logic formalism, the proof checking algorithm is defined on Proof Text Logic input. The algorithm makes use of automated theorem provers for checking the correctness of single proof steps. In this way, the proof steps in the input text do not need to be as fine-grained as in formal proof calculi, but may contain several reasoning steps at once, just as is usual in natural mathematical texts. The proof checking algorithm has to recognize implicit dynamic function introductions in the input text and has to take care of presuppositions of mathematical statements according to the principles of the formal account of presuppositions mentioned above. We prove two soundness and two completeness theorems for the proof checking algorithm: In each case one theorem compares the algorithm to the semantics of Proof Text Logic and one theorem compares it to the semantics of standard first-order predicate logic. As a case study for the theory developed in the thesis, we illustrate the working of the Naproche system on a controlled natural language adaptation of the beginning of Edmund Landau's Grundlagen der Analysis.Beweisprüfung mathematischer Texte in kontrollierter natürlicher Sprache Die Forschung, die für diese Dissertation durchgeführt wurde, basiert auf der Vision eines Computerprogramms, das die Korrektheit von mathematischen Beweisen, die in der gewöhnlichen mathematischen Fachsprache verfasst sind, überprüfen kann. Da die zuverlässige automatische Bearbeitung von uneingeschränktem natürlich-sprachlichen Input außer Reichweite der gegenwärtigen Technologie ist, haben wir uns auf das erreichbare Ziel fokussiert, eine kontrollierte natürliche Sprache (eine Teilmenge der natürlichen Sprache, die durch eine formale Grammatik definiert ist) als Eingabesprache für ein solches Programm zu verwenden. Wir haben einen Prototypen eines solchen Computerprogramms, das Naproche-System, entwickelt. Die vorliegende Dissertation beschreibt die neuartigen logischen und linguistischen Theorien, die benötigt werden, um die kontrollierte natürliche Sprache und den Beweisprüfungs-Algorithmus des Naproche-Systems zu definieren und zu motivieren. Diese Theorien stellen Methoden zu Verfügung, die dazu verwendet werden können, die weite Kluft zwischen natürlichen und formalen mathematischen Beweisen zu überbrücken. Wir erklären, wie unser System existierende linguistische Formalismen verwendet und erweitert, um die Besonderheiten der mathematischen Fachsprache zu analysieren. In diesem Zusammenhang beschreiben wir ein Phänomen dieser Fachsprache, das bisher von Logikern und Linguisten nicht beschrieben wurde – die implizite dynamische Funktionseinführung, die durch Konstruktionen der vorm "für jedes x gibt es ein f(x), so dass ..." veranschaulicht werden kann. Wir zeigen, wie diese Funktionseinführung zu einer der Russellschen analogen Antinomie führt. Um dieses Problem zu lösen, haben wir eine neuartige Grundlagentheorie für Funktionen entwickelt, die Ackermann-artige Funktionstheorie, die äquikonsistent zu ZFC (Zermelo-Fraenkel-Mengenlehre mit Auswahlaxiom) ist und verwendet werden kann, um der impliziten dynamischen Funktionseinführung Grenzen zu setzen, die zur Vermeidung dieser Antinomie führen. Wir beschreiben die implizite dynamische Funktionseinführung formal, indem wir die Dynamische Prädikatenlogik – ein Formalismus, der von Linguisten entwickelt wurde, um die dynamischen Eigenschaften der natürlich-sprachlichen Quantifizierung zu erfassen – zur Dynamischen Prädikatenlogik Höherer Stufe erweitern, deren Semantik auf der Ackermann-artigen Funktionstheorie basiert. Die Dynamische Prädikatenlogik Höherer Stufe formalisiert auch die linguistische Theorie der Präsuppositionen, die wir verwenden, um den Gebrauch potentiell undefinierter Terme (z.B. der Term 1/x, der für x=0 undefiniert ist) und bestimmter Kennzeichnungen (z.B. "die gerade Primzahl") in der mathematischen Fachsprache zu modellieren. Die Semantik der kontrollierten natürlichen Sprache wird definiert durch eine Übersetzung dieser in eine Erweiterung der Dynamischen Prädikatenlogik Höherer Stufe mit der Bezeichnung Beweistext-Logik. Die Beweistext-Logik erweitert die Dynamische Prädikatenlogik Höherer Stufe in zwei Hinsichten: Sie stellt Funktionalitäten für die Repräsentation von vollständigen Texten, und nicht nur von Einzelaussagen, zur Verfügung, und anstatt auf der Ackermann-artigen Funktionstheorie zu basieren, basiert sie auf einer reichhaltigeren Grundlagentheorie – der Klassen-Abbildungs-Tupel-Zahlen-Theorie, die neben Abbildungen/Funktionen auch noch Klassen/Mengen, Tupel, Zahlen und boolesche Werte als Grundobjekte zur Verfügung stellt. Der Beweisprüfungs-Algorithmus prüft die deduktive Korrektheit von Beweistexten, die in der kontrollierten natürlichen Sprache des Naproche-Systems verfasst sind. Da die Semantik dieser kontrollierten natürlichen Sprache durch eine Übersetzung in die Beweistext-Logik definiert ist, ist der Beweisprüfungs-Algorithmus für Beweistext-Logik-Input definiert. Der Algorithmus verwendet automatische Beweiser für die Überprüfung einzelner Beweisschritte. Dadurch müssen die Beweisschritte in dem Eingabetext nicht so kleinschrittig sein wie in formalen Beweiskalkülen, sondern können mehrere Deduktionsschritte zu einem Schritt vereinen, so wie dies auch in natürlichen mathematischen Texten üblich ist. Der Beweisprüfungs-Algorithmus muss die impliziten Funktionseinführungen im Eingabetext erkennen und Präsuppositionen von mathematischen Aussagen auf Grundlage der oben erwähnten Präsuppositionstheorie behandeln. Wir beweisen zwei Korrektheits- und zwei Vollständigkeitssätze für den Beweisprüfungs-Algorithmus: Jeweils einer dieser Sätze vergleicht den Algorithmus mit der Semantik der Beweistext-Logik und jeweils einer mit der Semantik der üblichen Prädikatenlogik erster Stufe. Als Fallstudie für die in dieser Dissertation entwickelte Theorie veranschaulichen wir die Funktionsweise des Naproche-Systems an einem an die kontrollierte natürliche Sprache angepassten Anfangsabschnitt von Edmund Landaus Grundlagen der Analysis