1,721,195 research outputs found
dlvhex: A System for Integrating Multiple Semantics in an Answer-Set Programming Framework
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
A practical view of answer-set programming transformations
Full text linkThe focus of this thesis is the examination of the practicality of applying known formal transformations of answer-set programs.Answer-set programming (ASP) is a formalism for declarative problem solving, based on the principles of non-monotonic reasoning. The research is started by constructing an overview of well-defined transformations existing in the scientific literature. We consider two systems of transformations -- one composed of certain syntactic transformations; the other of the semantic removal of rules and literals. This work then discusses algorithms for implementing applicability checking within the two systems, either existing ones from the literature, or new ones. Next, it is shown how to effectively process input data within the defined frameworks, utilizing properties related to the interactions between the transformations. With the help of a Python implementation, several data sets composed of answer-set programs are checked for transformation applicability, including: student-written programs, randomly-generated programs, and programs created by various front-ends for declarative problem solving.The results obtained show that the utility of applying the considered program transformations is quite low. Barring random input, only a small number of applicable transformation instances is found. Moreover, sequences of transformation applications are almost non-existent. Hence, there is little gain in using the considered transformation for online or offline optimization.Diese Arbeit beschäftigt sich mit der Untersuchung des praktisches Nutzens von formalen Transformationen in der Answer-Set Programmen. Answer-Set Programmierung (ASP) ist ein für deklaratives Problemlösen bestimmter Formalismus, der auf Prinzipien des nichtmonotonen Schließens aufbaut.Wir beginnen mit einer Übersicht des heutigen Stands in dem Feld. Unsere Unter- suchungen basieren auf zwei unterschiedlichen Transformationssysteme - eines, dass auf bestimmten syntaktischen Transformationen basiert; und ein zweites, welches auf semantischen Bedingungen aufbaut und redundante Regeln so wie Literale entfernt.Anschließend wird eine Diskussion über die Implementierung von Algorithmen zur Bestimmung der Anwendbarkeit von Regeln für diese zwei Systeme durchgeführt. Danach zeigen wir mit Hilfe der Interaktionseigenschaften der Transformationen, wie die Eingabedaten intern effektiv behandelt werden können.Eine Implementierung in Python wird benutzt, um eine Untersuchung der Anwend- barkeit der Transformationen bezüglich unterschiedlichen Beispielprogrammen durchzuführen. Analysiert werden, unter anderem, Studentenprogramme, zufallsgenerierte Programme, und automatisch generierte Programme erzeugt von verschiedenen Frontends für deklaratives Problemlösen.Die Resultate zeigen, dass die betrachteten Transformationen nur eine geringe Anwendbarkeit besitzen. Außer für den Fall von Zufallsprogrammem wird nur eine kleine Anzahl von Anwendungsinstanzen gefunden. Folgen von anwendbaren Transformationen sind praktisch nicht existent.Somit ist der praktische Nutzen für diese in der Literatur diskutierten Transformationen für Online- oder Offline-Optimierung gering.<br /
Nested HEX-Programs
No full textAnswer-Set Programming (ASP) is an established declarative programming paradigm. However, classical ASP lacks subprogram calls as in procedural programming, and access to external computations (like remote procedure calls) in general. The feature is desired for increasing modularity and---assuming proper access in place---(meta-)reasoning over subprogram results. While HEX-programs extend classical ASP with external source access, they do not support calls of (sub-)programs upfront. We present nested HEX-programs, which extend HEX-programs to serve the desired feature, in a user-friendly manner. Notably, the answer sets of called sub-programs can be individually accessed. This is particularly useful for applications that need to reason over answer sets like belief set merging, user-defined aggregate functions, or preferences of answer sets
Methods of affective artificial intelligence and an application for traffic simulation with emotional drivers
Full text linkEmotionen spielen eine zentrale Rolle in unserem Leben, dennoch wurden sie bis noch vor kurzem im Bereich der KI ignoriert. Dies änderte sich durch die Entstehung des neuen Forschungsgebietes Affective Computing. Dieses behandelt hauptsächlich die Erkennung und die Synthese von Emotionen.Diese Arbeit liefert einen Überblick über manche der Methoden des Affective Computings, einschliesslich diverser Theorien zur menschlichen Emotion sowie relevante Emotionsmodelle zur Anwendung in Agentensystemen. Weiters wird -- aufbauend auf einem speziellen hormonellen Emotionsmodell -- eine Anwendung zur Verkehrssimulation mit emotionalen Agenten vorgestellt, die im Zuge dieser Arbeit entwickelt wurde. Mit diesem Modell haben die Agenten die Möglichkeit sich glücklich, traurig, zornig oder ängstlich zu "fühlen" -- Zustände, die ihr Fahrverhalten beeinflussen. Experimente mit dieser Simulation bestätigen Erkenntnisse aus der Verkehrspsychologie; so konnte mit verschiedenen Persönlichkeitstypen reproduziert werden, dass Emotionen einen negativen Einfluss auf das Fahrverhalten und somit auf die Staubildung haben.Emotions play a vital role in our lives, yet they have been largely ignored by AI until the recent emergence of the field of Affective Computing that mainly deals with the recognition and synthesis of emotions. This thesis gives an overview about some methods of Affective Computing, including emotion theories and relevant models concerning agent behavior. Furthermore, based on a specific hormonal emotion model, an application for traffic simulation using emotional agents was developed. In the employed model, the agents have the ability to "feel" happy, sad, angry, or fearful---states affecting their driving behavior.Experiments with the implementation support findings in traffic research, where the evaluation of the simulation of various personality types led to the conclusion that emotions have a negative effect on driving behavior and the formation of traffic jams
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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