Experimental research on the development of Ceratium hirundinella O.F.Muller [Translation from: Z.Bot. 14, 337-371, 1922]

The most important aim of this study lay in filling in the great gap in our knowledge of the processes of germination in the Ceratium cyst and the early developmental stages in the standing stock of Ceratium hirundinella. contained rich cysts, we now succeeded extraordinarily well in pursuing the consistent development of Ceratium from the cyst to the completed cell. A series of experiments were carried out on the cysts and the juvenile stages of Ceratium, which showed very interesting results. The author presents in a general descriptive part the normal processes of germination in Ceratium cysts and the development of the juvenile stages in order to show in an experimental part the changes in form of C. hirundinella under the influence of temperature, light and varying salinities

Verified Analysis of Functional Data Structures

In recent work the author has analyzed a number of classical functional search tree and priority queue implementations with the help of the theorem prover Isabelle/HOL. The functional correctness proofs of AVL trees, red-black trees, 2-3 trees, 2-3-4 trees, 1-2 brother trees, AA trees and splay trees could be automated. The amortized logarithmic complexity of skew heaps, splay trees, splay heaps and pairing heaps had to be proved manually

Making security type systems less ad hoc

We present a uniform, top-down design method for security type systems applied to a parallel while-language. The method takes the following route: from a notion of end-to-end security via a collection of stronger notions of anytime security targeting compositionality to a matching collection of type-system-like syntactic criteria. This method has emerged by distilling and unifying security type system results from the literature while formalizing them in a proof assistant. Unlike in our previous papers on this topic, here we focus entirely on high-level ideas instead of technical proof details

Zum Verständnis von Bildung und Erziehung bei der Werte-Erziehung in der Schule

Das Verständnis von Bildung und Erziehung einschließlich Werte-Erziehung ist von übergreifenden und sich geschichtlich verändernden Voraussetzungen in der Gesellschaft und allgemeinen Funktionen der Schule abhängig. Zunächst ist auf diesen zweifachen Rahmen einzugehen, der bereits wichtige Aspekte des Themas erhellt. Erst anschließend sei gezeigt, welche wertpädagogische Relevanz eine integrative formale Definition von „Bildung" hat, die „Erziehung" und „Werte-Erziehung" mit umfasst. Sodann soll im Anschluss an eine zweite, normative Definition kritischer Bildung im Kontext der Didaktik aufgewiesen werden, wie sich Bildung und Erziehung von „Indoktrination" unterscheiden, die jede Erziehung potenziell als Schatten begleitet. (DIPF/Orig.

Remote-scope Promotion: Clarified, Rectified, and Verified

Modern accelerator programming frameworks, such as OpenCL, organise threads into work-groups. Remote-scope promotion (RSP) is a language extension recently proposed by AMD researchers that is designed to enable applications, for the first time, both to optimise for the common case of intra-work-group communication (using memory scopes to provide consistency only within a work-group) and to allow occasional inter-work-group communication (as required, for instance, to support the popular load-balancing idiom of work stealing). We present the first formal, axiomatic memory model of OpenCL extended with RSP. We have extended the Herd memory model simulator with support for OpenCL kernels that exploit RSP, and used it to discover bugs in several litmus tests and a work-stealing queue, that have been used previously in the study of RSP. We have also formalised the proposed GPU implementation of RSP. The formalisation process allowed us to identify bugs in the description of RSP that could result in well-synchronised programs experiencing memory inconsistencies. We present and prove sound a new implementation of RSP that incorporates bug fixes and requires less non-standard hardware than the original implementation. This work, a collaboration between academia and industry, clearly demonstrates how, when designing hardware support for a new concurrent language feature, the early application of formal tools and techniques can help to prevent errors, such as those we have found, from making it into silicon

Religion in pedagogics?

Im eröffnenden Abschnitt (I) wird aus wissenschafts-, gesellschafts- und problemgeschichtlichen Gründen zu erklären versucht, warum Religion in der Pädagogik seit den 60er Jahren fast gar nicht mehr thematisiert wird, es sei denn, die Doppelfrage nach Zusammenhang und Einheit der Pädagogik und nach ihrer Beziehung zur gesellschaftlichen Gesamtpraxis holt die Erziehungswissenschaft ein und führt die individuelle und kulturelle Funktion von Religion wieder vor Augen. Im Rückgang auf den neuzeitlichen Prozeß der gesellschaftlich-kulturellen Ausdifferenzierung legt der zweite Abschnitt (II) nahe, die christliche Religion nicht pauschal zu beurteilen sondern ebenfalls in ihrer geschichtlichen Ausdifferenzierung als kirchliches, gesellschaftliches und persönliches Christentum wahrzunehmen (so schon Rousseau und Pestalozzi) sowie bestimmte Grundmotive pädagogischen Denkens seit der Aufklärung in ihrem dialektischen Verhältnis zur voraufgehenden christentumsgeschichtlichen Entwicklung (Pietismus) einschließlich der biblischen Ursprünge zu begreifen. Vorbereitet durch reformatorische Unterscheidungen gelingt es Schleiermacher, die moderne Differenzierung wissenschaftstheoretisch so zu berücksichtigen, daß Theologie und Pädagogik nicht einander subordiniert werden und religiöse Bildung als eigenständiges Thema hier wie dort behandelt wird (III). Die Ergebnisse werden im Schlußabschnitt (IV) präzisiert und entfaltet. Hierbei wird klargestellt, daß die vertretenen Ansichten nicht ein überall geteiltes Selbstverständnis der Pädagogik und der Evangelischen Theologie spiegeln. Gegenüber Mißverständnissen wird herausgearbeitet, daß jede Verständigung zwischen Pädagogik und Theologie unter dem Prinzip der uneingeschränkten Achtung vor den bestehen bleibenden Differenzen zu suchen ist. (DIPF/Orig.)In the opening section (I), the author attempts a historical explanation of the fact that, since the 1960s, religion has hardly been dealt with in pedagogics and, if so, only when the twofold question of the coherence and unity of pedagogics and its relation to the overall social practice caught up with educational science and reminded us of the individual and cultural function of religion. Referring to the modern process of socio-cultural differentiation, the author then (II) suggests to refrain from passing a sweeping judgement on Christian religion but rather to perceive it, too, in its historical development as ecclesiastical, social, and personal Christianity (just as Rousseau and Pestalozzi did before) and to conceive certain basic motives of pedagogical thought since the Enlightenment in their dialectical relation to the preceding development in the history of Christianity (Pietism), including biblical origins. On the basis of reformatory distinctions, Schleiermacher is able to show that theology and pedagogics are not subordinated to one another and that religious education is considered an independent topic in both fields (III). In a final part (IV), the results are specified and enlarged upon. In this, it is made clear that the view the author has taken does not reflect a common self-concept shared by the whole of pedagogics and of Protestant theology. In order to avoid misunderstandings, it is shown that the discourse between pedagogics and theology has to be based on the principle of unrestricted respect for the persisting differences. (DIPF/Orig.

Möglichkeiten und Grenzen eines evolutionären Paradigmas in der Erziehungswissenschaft

Die Evolutionsforschung ist ausdifferenziert und erfordert einen entsprechend differenzierenden Umgang. Es werden ein sektoraler und ein paradigmatischer Gebrauch beschrieben. Ein geschlossenes "evolutionäres Paradigma" existiert nicht; zwei Hauptvarianten werden hinsichtlich ihrer Brauchbarkeit für die Pädagogik untersucht: der Ansatz der Soziobiologie und der einer systemtheoretisch orientierten Allgemeinen Evolutionstheorie. Anthropologische Kernprobleme betreffen die menschliche Freiheit und die Frage des Bösen in der menschlichen Natur. An den Themenfeldern von Kooperation und Abgrenzung, Indoktrinierbarkeit und Indoktrination werden fruchtbare Rezeptionsmöglichkeiten konkretisiert. (DIPF/Orig.)Evolutionary research is by now well differentiated and requests, in turn, a differentiated approach. The author describes both a sectoral and a paradigmatic use. A self-contained “evolutionary paradigm” does not exist; two major variants are examined as to their use for pedagogics, - the socio-biological approach and that of a system-theoretically oriented general evolutionary theory. Core problems in anthropology concern human liberty and the question of evil in human nature. The topics of cooperation, delimitation, and indoctrination are used to explain more concretely promising ways of adoption. (DIPF/Orig.

Noninterfering schedulers: when possibilistic noninterference implies probabilistic noninterference

We develop a framework for expressing and analyzing the behavior of probabilistic schedulers. There, we define noninterfering schedulers by a probabilistic interpretation of Goguen and Meseguer’s seminal notion of noninterference. Noninterfering schedulers are proved to be safe in the following sense: if a multi-threaded program is possibilistically noninterfering, then it is also probabilistically noninterfering when run under this scheduler

Making security type systems less ad hoc

We present a uniform, top-down design method for security type systems applied to a parallel while-language. The method takes the following route: from a notion of end-to-end security via a collection of stronger notions of anytime security targeting compositionality to a matching collection of type-system-like syntactic criteria. This method has emerged by distilling and unifying security type system results from the literature while formalizing them in a proof assistant. Unlike in our previous papers on this topic, here we focus entirely on high-level ideas instead of technical proof details