Duality of Channel Encoding and Decoding - Part I: Rate-1 Binary Convolutional Codes

In this paper, we revisit the forward, backward and bidirectional Bahl-Cocke-Jelinek-Raviv (BCJR) soft-input soft-output (SISO) maximum a posteriori probability (MAP) decoding process of rate-1 binary convolutional codes. From this we establish some interesting explicit relationships between encoding and decoding of rate-1 convolutional codes. We observe that the forward and backward BCJR SISO MAP decoders can be simply represented by their dual SISO channel encoders using shift registers in the complex number field. Similarly, the bidirectional MAP decoding can be implemented by linearly combining the shift register contents of the dual SISO encoders of the respective forward and backward decoders. The dual encoder structures for various recursive and non-recursive rate-1 convolutional codes are derived.Comment: 32 pages, 20 figures, to appear in ET

Challenges and prospects of spatial machine learning

The main objective of this thesis is to improve the usefulness of spatial machine learning for the spatial sciences and to allow its unused potential to be exploited. To achieve this objective, this thesis addresses several important but distinct challenges which spatial machine learning is facing. These are the modeling of spatial autocorrelation and spatial heterogeneity, the selection of an appropriate model for a given spatial problem, and the understanding of complex spatial machine learning models.Das wesentliche Ziel dieser Arbeit ist es, die Nützlichkeit des räumlichen maschinellen Lernens für die Raumwissenschaften zu verbessern und es zu ermöglichen, ungenutztes Potenzial auszuschöpfen. Um dieses Ziel zu erreichen, befasst sich diese Arbeit mit mehreren wichtigen Herausforderungen, denen das räumliche maschinelle Lernen gegenübersteht. Diese sind die Modellierung von räumlicher Autokorrelation und räumlicher Heterogenität, die Auswahl eines geeigneten Modells für ein gegebenes räumliches Problem und das Verständnis komplexer räumlicher maschineller Lernmodelle

The Potential of Qualitative Content Analysis for Empirical Educational Research

Researchers carrying out empirical studies in education are faced with complex and multifaceted phenomena that need to be investigated from different perspectives and with various methodological approaches. A suitable, often-applied method in empirical educational research is qualitative content analysis (QCA), developed by Philipp MAYRING (1983, 2015). This method can be used for inductive and deductive strategies of analysis, and is appropriate for combining qualitative and quantitative analyses, especially for research strategies based on mixed methods approaches (CRESWELL, 2015), which have for several years now been extensively discussed in empirical educational research (GLÄSER-ZIKUDA, SEIDEL, ROHLFS, GRÖSCHNER & ZIEGELBAUER, 2012; HAGENAUER & GLÄSER-ZIKUDA, 2019; MAYRING & GLÄSER-ZIKUDA, 2008). In this article, we discuss the potential of QCA for empirical educational research by giving insights into the basics of analysis and by providing research examples. We also briefly address the relevance of digitally supported analysis and describe specific software packages. Finally, we discuss the potential and challenges of applying QCA within mixed methods designs in the field of empirical educational research.Wissenschaftler_innen, die empirische Studien im Bildungsbereich durchführen, stehen einem komplexen Forschungsfeld gegenüber, das aus unterschiedlichen Perspektiven sowie mit vielfältigen methodischen Zugängen zu bearbeiten ist. Eine speziell in der empirischen Bildungsforschung häufig angewandte und geeignete Auswertungsmethode ist die von Philipp MAYRING (1983, 2015) entwickelte qualitative Inhaltsanalyse. Sie kann für induktive und deduktive Analysestrategien verwendet werden. Insbesondere wird sie in Studien genutzt, die eine Kombination qualitativer und quantitativer Analysen speziell im Sinne von Mixed-Methods-Ansätzen (CRESWELL 2015) anstreben. Diese werden seit geraumer Zeit intensiv in der empirischen Bildungsforschung diskutiert (GLÄSER-ZIKUDA, SEIDEL, ROHLFS, GRÖSCHNER & ZIEGELBAUER 2012; HAGENAUER & GLÄSER-ZIKUDA 2019; MAYRING & GLÄSER-ZIKUDA 2008). In diesem Beitrag diskutieren wir die qualitative Inhaltsanalyse hinsichtlich ihres Potenzials für die empirische Bildungsforschung, indem wir einen Überblick über die Grundlagen der Methode geben und ausgewählte Forschungsbeispiele vorstellen. Wir gehen dabei auch kurz auf die Möglichkeiten und die Bedeutung digital unterstützter Datenanalyse ein und beschreiben ausgewählte Software. Abschließend werden Chancen sowie Herausforderungen der Anwendung qualitativer Inhaltsanalyse mit Blick auf Mixed-Method-Designs in der empirischen Bildungsforschung diskutiert

University teachers’ perceptions of appropriate emotion display and high-quality teacher-student relationship: Similarities and differences across cultural-educational contexts

 Research on teachers’ emotion display and the quality of the teacher-student relationship in higher education is increasingly significant in the context of rapidly developing internationalization in higher education, with scholars (and students) moving across countries for research and teaching. However, there is little theoretically grounded empirical research in this area, and the different research strands remain relatively unconnected. The present study aimed to address this gap. Psychological, educational and cross-cultural theories were brought together to investigate the interplay of emotion display and the quality of the teacher-student relationship from a teachers’ perspective and across “cultural-educational” context. Given that social interaction, and the mores and norms associated with emotions display are often culturally underpinned, this study explored how university teachers in two so-called “individualistic” countries with different educational systems displayed positive and negative emotions in their teaching and what they perceived as an ideal teacher-student relationship. Australian (N = 15) and German (N = 9) university teachers in teacher education were interviewed. The study revealed that while both groups viewed the open expression of positive emotions as integral to teaching, and negative emotions to be controlled based on their understanding of professionalism, significant group differences also emerged. While the Australian teacher educators reported higher and more intense expression of positive emotions their German counterparts reported more open anger display. Subtle yet noteworthy difference in the TSR quality between the two groups of teachers also emerged. The findings of this study have implications for research and practice in international higher education.

Pubertal hormones alter circadian timekeeping: Evidence from two rodent models, Rattus norvegicus and Octodon degus.

There is overwhelming evidence that the circadian timekeeping system is sensitive to gonadal hormones during perinatal development and adulthood. However, there is a noticeable lack of research in animal models focusing on circadian rhythms during puberty, a developmental window of dramatic hormonal change. This dissertation addresses this research gap using experiments in both fast-developing and slow-developing rodent species (Rattus norvegicus and Octodon degus). The results indicate that the circadian system continues to develop across the post-weaning and pubertal periods in both species in a manner that exhibits strong sex differences. In males, pubertal changes in activity rhythms were robust, involving a switch from bimodal to unimodal activity patterns as well as a 3-5 hr magnitude phase-advance of activity rhythms relative to the environmental light-dark cycle. Pre-pubertal gonadectomy diminished these changes in both species, indicating that pubertal hormones were involved in producing the changes. Overall, females showed smaller circadian phase changes than males during puberty. In the degu, these sex differences were extreme, with female degus almost completely lacking phase changes during puberty. Results suggest that pubertal hormones could act on multiple components of the circadian system. For example, preliminary data from the degu suggest that a photosensitive rhythmic component of the central circadian oscillator (Per1) exhibits phase changes during puberty that parallel phase changes in behavioral rhythms. However, pubertal rats exhibited a reorganization of activity rhythms under constant conditions, independent of photic entrainment. Thus, both the photic entrainment pathway and downstream circadian elements may be altered during puberty. Taken in tandem with growing evidence from multiple species, as well as sleep electrophysiological studies from our own lab, it appears that the processes governing daily sleep and activity rhythms continue to develop far into the pubertal period in many mammals. This conclusion is discussed in the context of the developmental ecology of these rodent species. The ramifications of these results for the wide-spread use of young animals by the scientific community for patch-clamp experiments of the circadian system are also discussed. Finally, this evidence can inform the national debate regarding teenage sleep patterns and high school start times.Ph.D.NeuroscienceUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/77936/1/hagenaue_1.pd

Focus estimation in academic environments using Computer Vision

In this paper we propose a system capable of monitoring students’ focus through cameras and using Computer Vision algorithms. Experimental results show that our system is capable of identifying students and tracking their focus during a class. At the end of the class, the system outputs graphical feedback to teachers regarding the average level of students’ focus. Moreover, it can identify lecture periods in which students were less watchful and the corresponding topics that potentially need extra focus. In this paper we start by presenting the architecture of the system, followed by results obtained both during a small-group workshop and a classroom with a large number of attending students. The main goal of this work is to contribute to the transformation of the classroom as a sensing environment, providing information to both teachers and students about their engagement during the class.publishe

SymbioCity: Smart Cities for Smarter Networks

The "Smart City" (SC) concept revolves around the idea of embodying cutting-edge ICT solutions in the very fabric of future cities, in order to offer new and better services to citizens while lowering the city management costs, both in monetary, social, and environmental terms. In this framework, communication technologies are perceived as subservient to the SC services, providing the means to collect and process the data needed to make the services function. In this paper, we propose a new vision in which technology and SC services are designed to take advantage of each other in a symbiotic manner. According to this new paradigm, which we call "SymbioCity", SC services can indeed be exploited to improve the performance of the same communication systems that provide them with data. Suggestive examples of this symbiotic ecosystem are discussed in the paper. The dissertation is then substantiated in a proof-of-concept case study, where we show how the traffic monitoring service provided by the London Smart City initiative can be used to predict the density of users in a certain zone and optimize the cellular service in that area.Comment: 14 pages, submitted for publication to ETT Transactions on Emerging Telecommunications Technologie

La gouvernance de l’implémentation curriculaire. Les variables explicatives de l’acceptation de l’innovation par les directeurs et directrices d’établissement scolaire

Schulleiterinnen und Schulleiter sind wichtige "change agents" bei der Einführung eines neuen Lehrplans (Lehrplan 21) in der Deutschschweiz. Aus interdisziplinärer Perspektive, welche governancetheoretische mit organisationspsychologischen Konzepten verknüpft, untersucht die vorliegende Studie, inwiefern ausser- und innerorganisationale Governancemerkmale der Lehrplaneinführung, sowie das individuelle Merkmal der emotionalen Gestimmtheit in Bezug auf die Lehrplaneinführung mit der Akzeptanz des Lehrplans 21 als Innovation zusammenhängen. Befragt wurden 359 Schulleiter/innen im Kanton Bern. Die Ergebnisse zeigen, dass das Erleben positiver Emotionen im Zusammenhang mit der Governance der Lehrplaneinführung hohe Erklärungskraft in Bezug auf die Akzeptanz der Innovation besitzt. Ausserdem weisen die Befunde darauf hin, dass ausserorganisationale Governancefaktoren für die Innovationsakzeptanz weniger bedeutsam sind als innerorganisationale Aspekte. (DIPF/Orig.)Les directeurs et directrices d’école sont des agents de changement clés dans la mise en place du nouveau plan d’études (Lehrplan 21 / Plan d’études 21) dans les cantons suisses alémaniques. Dans une perspective interdisciplinaire qui allie des concepts de la gouvernance éducative et de la psychologie organisationnelle, la présente étude examine les liens que les facteurs de gouvernance externes et internes à l’école et l’expérience émotionnelle de ces facteurs de gouvernance lors de la mise en place du plan d’études entretiennent avec l’acceptation de l’innovation par les directions d’établissement. Les données ont été recueillies à l’aide d’un questionnaire standardisé renseigné par 359 directions d’établissement du canton de Berne. Les résultats montrent que les facteurs de gouvernance internes à l’école et l’expérience émotionnelle positive de la gouvernance du changement prédisent fortement l’acceptation de l’innovation par les directeurs-trices, alors que les facteurs de gouvernance externes à l’école n’ont qu’un faible pouvoir explicatif. (DIPF/Orig.