RelAndXML

Diese Dissertation stellt das neu entwickelte SystemRelAndXML vor, das für das Management und dieSpeicherung von hypertextzentrierten XML-Dokumenten und dendazugehörenden XSL-Stylesheets spezialisiert ist. DerAnwendungsbereich sind die Vorlesungsmaterialien anUniversitäten. RelAndXML speichert die XML-formatiertenÜbungsblätter in Textbausteinen und weiterenTeilen in einer speziellen Datenbank.Die Speicherung von XML-Dokumenten in Datenbanken ist seiteinigen Jahren ein wichtiges Thema der Datenbankforschung.Ansätze dafür gliedern sich in solche fürdatenzentrierte und andere für dokumentenzentrierteDokumente. Die Dissertation präsentiert einen Ansatzzur Speicherung von hypertextzentrierten XML-Dokumenten, derAspekte von datenzentrierten und dokumentenzentriertenAnsätzen kombiniert. Der Ansatz erlaubt dieWiederverwendung von Textbausteinen und speichert dieReihenfolge dort, wo sie wichtig ist. Mit RelAndXML könnennicht nur Elemente gespeichert werden, wie mit einigenanderen Ansätzen, sondern auch Attribute, Kommentareund Processing Instructions. Algorithmen für dieFragmentierung und Rekonstruktion von Dokumenten werdenbereit gestellt.RelAndXML wurde mit Java und unter Verwendung einerobjektrelationalen Datenbank implementiert. Das System hateine graphische Benutzungsoberfläche, die das Erstellenund Verändern der XML- und XSL-Dokumente, dasEinfügen von neuen oder schon gespeichertenTextbausteinen sowie das Erzeugen von HTML-Dokumenten zurVeröffentlichung ermöglicht.

Empirische Studie zum Leseverständnis und Lernen mit hypermedialen Texten bei Grundschulkindern

Die zentrale Untersuchungsfrage lautet: Welche Voraussetzungen müssen Kinder mitbringen, um Lernsoftware optimal nutzen zu können? Diese Frage wurde anhand der Voraussetzung „Leseverständnis“, als Basiskompetenz, sowie darüber hinausgehenden Voraussetzungen, „Interesse“ und „PC-Erfahrung“, untersucht. Die Studie „Lesen am Computer“ (LaC) betrachtete erstmals die effiziente Nutzung von Informationsquellen. Das Verhältnis von Print- und Hypertext-Lesekompetenz sowie Einflussfaktoren wurden hierbei erkundet. Es handelte sich um eine Zusatzstudie zur Internationalen Grundschul-Leseuntersuchung (IGLU) bzw. zur Erhebung „Kompetenzen und Einstellungen von Schülerinnen und Schülern (KESS). Die vorliegende Arbeit stellt eine quantitative Studie dar, wobei qualitative Methoden die Aussagen unterstützen. Es wurde das Leseverständnis von Mädchen und Jungen einer Hamburger Grundschule gemessen. Unter Berücksichtigung der Faktoren „Interesse am Thema und/oder Lernsoftware“ sowie „PC-Erfahrung“ wurde das Leseverständnis zum Multimediaverständnis in Beziehung gesetzt. Darüber hinaus wurden die Rezeptionsprozesse beobachtet und einzelne Fallbeispiele zur Interpretation herangezogen. Die Untersuchung hat gezeigt, dass die wichtigste Basisqualifikation beim Lernen mit neuen Medien ein gutes Leseverständnis ist und die Mädchen zum einen über ein besseres Leseverständnis und zum anderen über ein besseres Multimediaverständnis als die Jungen verfügen. Des Weiteren konnte dargelegt werden, dass sich die PC-Praxis eines Kindes nicht zwangsläufig mit seinen Fertigkeiten im Programm deckt und eine gute PC-Praxis hauptsächlich bei Kindern mit einem mäßigen Leseverständnis förderlich ist. Es lässt sich außerdem festhalten, dass die meisten Kinder Interesse am Thema aufweisen und dies überwiegend mit einem guten Leseverständnis und einem überdurchschnittlichen Multimediaverständnis gekoppelt ist. Die Hauptaufgaben des Unterrichts beziehen sich folglich auf das Arrangement von Lernprozessen. Die Einteilung in Rezeptionstypen ist eine wesentliche Aufgabe, um dementsprechend Teams zu bilden und Defizite auszugleichen. Ferner müssen Kinder mit einem guten bzw. mäßigen Leseverständnis unterschiedlich gefördert werden.

Linguistic Stylistics

Marina Katnic-Bakarsic. Linguistic Stylistics The practical, i.e. educational, objective of this research was to produce lectures on linguistic stylistics for the students of Sarajevo University, while the theoretical one was to produce a monograph on the subject. This monograph, which can also be used as a university textbook, includes twenty-nine chapters, an index of topics, a bibliography and a list of sources. The theoretical postulates are followed by examples from texts in various functional styles in Bosnian, Croatian, Serbian, and in some cases Russian or English. Linguo-stylistic problems were investigated from both the structuralist and post-structuralist points of view. Linguistic stylistics is therefore understood as a discipline which studies expressive, stylistically marked language units on all language levels, functional-stylistic language variation and various aspects of intertextuality and metatext. The author introduces a notion of stylistic competence. The stylistic competence of a speaker is directly proportional to his/her knowledge of different varieties of language (i.e. subcodes) and to the successful switching from one subcode to another. Stylistic creativity is a special segment of stylistic competence as a feature of individual style. A new classification of functional styles has also been introduced. This includes six primary styles (scientific, colloquial, administrative, publicistic, journalistic and literary-artistic) and five secondary styles (oratorical, the style of advertisements and commercials, that of comics, that of essays and that of screenplays). A special place is given to the analysis of the style of hypertext and hypermedia, which can be understood only within the post-structuralist theory of text deconstruction and intertextuality. The project also analysed some new topics, including reregistration in literary texts, gender and style of dialogue, and citations as metatextual signals and their role in different types of text. The results therefore offer a new approach to the study of linguistic stylistics both in Bosnia and Herzegovina and in the field in general.

Lernen im digitalen Themenraum. Exploratives Lernen im Internet aus kunsthistorischer Sicht

Die Vorteile der verbesserten Präsentation von Informationen durch Neue Medien auch im Seminarkontext und die komfortable Beschaffung von Informationen im Internet sind evident. Sie ergänzen und verbessern die herkömmlichen Arbeits- und Lernstrukturen. Möchte man die Neuen Medien aber als didaktisches Mittel einsetzen, so müssen die medienspezifischen Bedingungen der Hypertextstruktur bei der Realisierung berücksichtigt werden. Für den Rezipienten bedeutet dies, dass er im Internet zur Aktivität aufgefordert werden muss, um sich im Wissensnetz zu bewegen. Während beim Buch die Textualität durch die Seitenfolge vorgegeben ist, muss der Anwender sich in der Hypertextstruktur seine Textualität selber konstruieren. Dahinter steht das Konzept des explorativen Lernens, in dem der Lernende Akteur ist, der seinen Lernweg selbst bestimmt und entscheidet, wann er welche Fragen stellen und beantworten möchte. Der Inhalt und seine Präsentation sind hierbei direkt voneinander abhängig. Daraus folgt zwingend eine gleichberechtigte Zusammenarbeit von Mediendidaktik, Design, Informatik und Fachwissenschaft. Nur eine solche ermöglicht die gemeinsame Realisierung eines digitalen Themenraums im Netz, dessen Konzeption an einem Beispiel veranschaulicht wird.

The Inverted Phantom Giant

In his famous children’s book, “Jim Button and Luke the Engine Driver”, Michael Ende describes a curious character: A phantom giant. Clothed in rags and with a long beard, the phantom giant appears enormous from far away, but shrinks to normal size as one gets closer. Most people avoid the poor creature, but the ones that dare approach it encounter a gentle, lonely being called Mr. Tur Tur. Chemical ecology is just the opposite of Mr. Tur Tur: A phantom dwarf. Or, in other words, an inverted phantom giant. From a distance, chemical ecology appears like a slightly odd, marginal section of biology and chemistry. But, as the interested scholar approaches, it starts growing and very quickly reaches gigantic dimensions, because all life is explained by chemistry, and all biological chemistry is guided by ecological principles. Herein lies the difficulty with chemical ecology: As it is not perceived well by biologists and chemists, few approach it to understand its significance, and the ones that do find themselves in front of a giant that defies their attempts to define and contain it. This is where the Journal of Chemical Ecology comes in: It invites us to take a closer look at an underestimated discipline and supports us to explore it and deal with its multidimensionality through the promotion of knowledge and methods. These services are unique and make the journal stand out of the crowd of scientific journals. Writing children’s books has become difficult in the era of information technology. And, so has the job of the Journal of Chemical Ecology. Young scientists gather information through accessible, dynamic websites and social platforms. They want articles that are available through a single mouse click, anywhere, anytime. They prefer advanced interactive hypertext protocols over clumsy pdf files. They care about transparency, non-profit and open access just as much as about traditional journal properties. In my view, reaching “the kids” is the major challenge of the Journal over the next years. Promoting an inverted phantom giant in the 21st century requires a combination of high-quality information and boosted visibility. In Michael Ende’s book, Jim and Luke follow exactly this strategy with Mr. Tur Tur: They become friends and offer him a job as a living lighthouse to protect their small island. They combine a quality relationship with high visibility, et voilà, the story ends well! I am looking forward to seeing if the Journal of Chemical Ecology will follow a similar path to reach the next generation of biologists and chemists. If yes, there is a good chance that in 40 years from now, somebody will write a laudation and refer to another famous book by Michael Ende: “The Neverending Story”.

La divulgación científica de análisis sensorial de vinos en soporte web

En esta tesis se trabaja sobre la hipótesis de que el componente didáctico del discurso divulgativo queda delimitado por estrategias discursivas originadas en el tratamiento modal y actualizadas en los niveles funcional, situacional, semántico y formal-gramatical. El objetivo es caracterizar tales estrategias para identificar tendencias en la realización lingüísticodiscursiva del componente didáctico. El corpus se ha formado teniendo en cuenta soporte (web), formato (hipertexto) y dominio disciplinar (Análisis Sensorial de Vinos). La metodología es, fundamentalmente, cualitativo-ejemplar, basada en el modelo multinivel propuesto por Ciapuscio (2003) para el análisis de textos especializados. Los resultados sugieren que en el nivel funcional, el componente didáctico se distingue por el predominio de los términos positivos de las categorías modales epistémica (función informar) y ética (función dirigir); en el nivel situacional, por tres tipos de construcciones discursivas: la del enunciador experto, la del enunciatario lego y la de la pertenencia del lego a la comunidad especializada; en el nivel semántico, por la estandarización de partes textuales y por el predominio tanto de axiologización eufórica ética y cognoscitiva, como de secuencias expositivas y de procedimientos explicativos causales, descriptivos e ilustrativos; en el nivel formal, por recursos paratextuales e hipertextuales que refuerzan la actualización del componente didáctico.

De la rueda de libros a la escritura enciclopédica

En 1588, el inventor italiano Agostino Ramelli publicó el libro Le diverse et artificiose machine. Entre las muchas máquinas de ingeniería hidráulica y militar, un total de 195 aparatos, destaca un artilugio construido para facilitar la lectura de varios libros a la vez. Esta llamada "rueda de libros" se suele citar en publicaciones recientes como precursora del hipertexto ya que esta máquina para leer permite saltar de un texto a otro de la misma manera que nos movemos entre páginas WEB y módulos textuales. Se trata de una invención que los investigadores describen como reacción al desafío que plantea la enorme cantidad de saber libresco que circula gracias a otra invención que era la imprenta con letras móviles. Aunque muy posiblemente nunca hubiera llegado a construirse, se trata de un artefacto que funciona potencialmente como una máquina de producir textos o, dicho de otra manera, como dispositivo de impulsar un determinado tipo de escritura. Me propongo leer florilegios, obras enciclopédicas y polianteas como Lugares comunes de Juan de Aranda o la escritura enciclopédica en obras como el Guzmán de Alfarache, La pícara Justina o el Libro de todas las cosas como productos virtuales de la rueda de libros.

De la rueda de libros a la escritura enciclopédica

En 1588, el inventor italiano Agostino Ramelli publicó el libro Le diverse et artificiose machine. Entre las muchas máquinas de ingeniería hidráulica y militar, un total de 195 aparatos, destaca un artilugio construido para facilitar la lectura de varios libros a la vez. Esta llamada "rueda de libros" se suele citar en publicaciones recientes como precursora del hipertexto ya que esta máquina para leer permite saltar de un texto a otro de la misma manera que nos movemos entre páginas WEB y módulos textuales. Se trata de una invención que los investigadores describen como reacción al desafío que plantea la enorme cantidad de saber libresco que circula gracias a otra invención que era la imprenta con letras móviles. Aunque muy posiblemente nunca hubiera llegado a construirse, se trata de un artefacto que funciona potencialmente como una máquina de producir textos o, dicho de otra manera, como dispositivo de impulsar un determinado tipo de escritura. Me propongo leer florilegios, obras enciclopédicas y polianteas como Lugares comunes de Juan de Aranda o la escritura enciclopédica en obras como el Guzmán de Alfarache, La pícara Justina o el Libro de todas las cosas como productos virtuales de la rueda de libros.

De la rueda de libros a la escritura enciclopédica

En 1588, el inventor italiano Agostino Ramelli publicó el libro Le diverse et artificiose machine. Entre las muchas máquinas de ingeniería hidráulica y militar, un total de 195 aparatos, destaca un artilugio construido para facilitar la lectura de varios libros a la vez. Esta llamada "rueda de libros" se suele citar en publicaciones recientes como precursora del hipertexto ya que esta máquina para leer permite saltar de un texto a otro de la misma manera que nos movemos entre páginas WEB y módulos textuales. Se trata de una invención que los investigadores describen como reacción al desafío que plantea la enorme cantidad de saber libresco que circula gracias a otra invención que era la imprenta con letras móviles. Aunque muy posiblemente nunca hubiera llegado a construirse, se trata de un artefacto que funciona potencialmente como una máquina de producir textos o, dicho de otra manera, como dispositivo de impulsar un determinado tipo de escritura. Me propongo leer florilegios, obras enciclopédicas y polianteas como Lugares comunes de Juan de Aranda o la escritura enciclopédica en obras como el Guzmán de Alfarache, La pícara Justina o el Libro de todas las cosas como productos virtuales de la rueda de libros.

Efficient local unfolding with ancestor stacks for full prolog

The integration of powerful partial evaluation methods into practical compilers for logic programs is still far from reality. This is related both to 1) efficiency issues and to 2) the complications of dealing with practical programs. Regarding efnciency, the most successful unfolding rules used nowadays are based on structural orders applied over (covering) ancestors, i.e., a subsequence of the atoms selected during a derivation. Unfortunately, maintaining the structure of the ancestor relation during unfolding introduces significant overhead. We propose an efficient, practical local unfolding rule based on the notion of covering ancestors which can be used in combination with any structural order and allows a stack-based implementation without losing any opportunities for specialization. Regarding the second issue, we propose assertion-based techniques which allow our approach to deal with real programs that include (Prolog) built-ins and external predicates in a very extensible manner. Finally, we report on our implementation of these techniques in a practical partial evaluator, embedded in a state of the art compiler which uses global analysis extensively (the Ciao compiler and, specifically, its preprocessor CiaoPP). The performance analysis of the resulting system shows that our techniques, in addition to dealing with practical programs, are also significantly more efficient in time and somewhat more efficient in memory than traditional tree-based implementations.

Abstraction-carrying code

Proof-Carrying Code (PCC) is a general approach to mobile code safety in which programs are augmented with a certifícate (or proof). The practical uptake of PCC greatly depends on the existence of a variety of enabling technologies which allow both to prove programs correct and to replace a costly verification process by an efñcient checking procedure on the consumer side. In this work we propose Abstraction-Carrying Code (ACC), a novel approach which uses abstract interpretation as enabling technology. We argüe that the large body of applications of abstract interpretation to program verification is amenable to the overall PCC scheme. In particular, we rely on an expressive class of safety policies which can be defined over different abstract domains. We use an abstraction (or abstract model) of the program computed by standard static analyzers as a certifícate. The validity of the abstraction on the consumer side is checked in a single-pass by a very efficient and specialized abstract-interpreter. We believe that ACC brings the expressiveness, flexibility and automation which is inherent in abstract interpretation techniques to the área of mobile code safety. We have implemented and benchmarked ACC within the Ciao system preprocessor. The experimental results show that the checking phase is indeed faster than the proof generation phase, and that the sizes of certificates are reasonable.

Experiments in abstract interpretation-based code certification for pervasive systems

Proof carrying code (PCC) is a general is originally a roof in ñrst-order logic of certain vermethodology for certifying that the execution of an un- ification onditions and the checking process involves trusted mobile code is safe. The baste idea is that the ensuring that the certifícate is indeed a valid ñrst-order code supplier attaches a certifícate to the mobile code proof. which the consumer checks in order to ensure that the The main practical difñculty of PCC techniques is in code is indeed safe. The potential benefit is that the generating safety certiñeates which at the same time: i) consumer's task is reduced from the level of proving to allow expressing interesting safety properties, ii) can be the level of checking. Recently, the abstract interpre- generated automatically and, iii) are easy and efficient tation techniques developed, in logic programming have to check. In [1], the abstract interpretation techniques been proposed as a basis for PCC. This extended ab- [5] developed in logic programming1 are proposed as stract reports on experiments which illustrate several is- a basis for PCC. They offer a number of advantages sues involved in abstract interpretation-based certifica- for dealing with the aforementioned issues. In particution. First, we describe the implementation of our sys- lar, the xpressiveness of existing abstract domains will tem in the context of CiaoPP: the preprocessor of the be implicitly available in abstract interpretation-based Ciao multi-paradigm programming system. Then, by code certification to deñne a wide range of safety propermeans of some experiments, we show how code certifi- ties. Furthermore, the approach inherits the automation catión is aided in the implementation of the framework. and inference power of the abstract interpretation en- Finally, we discuss the application of our method within gines used in (Constraint) Logic Programming, (C)LP. the área, of pervasive systems

Efficient negation using abstract interpretation

While negation has been a very active área of research in logic programming, comparatively few papers have been devoted to implementation issues. Furthermore, the negation-related capabilities of current Prolog systems are limited. We recently presented a novel method for incorporating negation in a Prolog compiler which takes a number of existing methods (some modified and improved by us) and uses them in a combined fashion. The method makes use of information provided by a global analysis of the source code. Our previous work focused on the systematic description of the techniques and the reasoning about correctness and completeness of the method, but provided no experimental evidence to evalúate the proposal. In this paper, we report on an implementation, using the Ciao Prolog system preprocessor, and provide experimental data which indicates that the method is not only feasible but also quite promising from the efficiency point of view. In addition, the tests have provided new insight as to how to improve the proposal further. Abstract interpretation techniques are shown to offer important improvements in this application.

Abstract Interpretation-based verification/certification in the ciaoPP system

CiaoPP is the abstract interpretation-based preprocessor of the Ciao multi-paradigm (Constraint) Logic Programming system. It uses modular, incremental abstract interpretation as a fundamental tool to obtain information about programs. In CiaoPP, the semantic approximations thus produced have been applied to perform high- and low-level optimizations during program compilation, including transformations such as múltiple abstract specialization, parallelization, partial evaluation, resource usage control, and program verification. More recently, novel and promising applications of such semantic approximations are being applied in the more general context of program development such as program verification. In this work, we describe our extensión of the system to incorpórate Abstraction-Carrying Code (ACC), a novel approach to mobile code safety. ACC follows the standard strategy of associating safety certificates to programs, originally proposed in Proof Carrying- Code. A distinguishing feature of ACC is that we use an abstraction (or abstract model) of the program computed by standard static analyzers as a certifícate. The validity of the abstraction on the consumer side is checked in a single-pass by a very efficient and specialized abstractinterpreter. We have implemented and benchmarked ACC within CiaoPP. The experimental results show that the checking phase is indeed faster than the proof generation phase, and that the sizes of certificates are reasonable. Moreover, the preprocessor is based on compile-time (and run-time) tools for the certification of CLP programs with resource consumption assurances.

Abstract specialization and its applications

The aim of program specialization is to optimize programs by exploiting certain knowledge about the context in which the program will execute. There exist many program manipulation techniques which allow specializing the program in different ways. Among them, one of the best known techniques is partial evaluation, often referred to simply as program specialization, which optimizes programs by specializing them for (partially) known input data. In this work we describe abstract specialization, a technique whose main features are: (1) specialization is performed with respect to "abstract" valúes rather than "concrete" ones, and (2) abstract interpretation rather than standard interpretation of the program is used in order to propágate information about execution states. The concept of abstract specialization is at the heart of the specialization system in CiaoPP, the Ciao system preprocessor. In this paper we present a unifying view of the different specialization techniques used in CiaoPP and discuss their potential applications by means of examples. The applications discussed include program parallelization, optimization of dynamic scheduling (concurreney), and integration of partial evaluation techniques.