Anomaly Detection in Paleoclimate Records using Permutation Entropy

Permutation entropy techniques can be useful in identifying anomalies in paleoclimate data records, including noise, outliers, and post-processing issues. We demonstrate this using weighted and unweighted permutation entropy of water-isotope records in a deep polar ice core. In one region of these isotope records, our previous calculations revealed an abrupt change in the complexity of the traces: specifically, in the amount of new information that appeared at every time step. We conjectured that this effect was due to noise introduced by an older laboratory instrument. In this paper, we validate that conjecture by re-analyzing a section of the ice core using a more-advanced version of the laboratory instrument. The anomalous noise levels are absent from the permutation entropy traces of the new data. In other sections of the core, we show that permutation entropy techniques can be used to identify anomalies in the raw data that are not associated with climatic or glaciological processes, but rather effects occurring during field work, laboratory analysis, or data post-processing. These examples make it clear that permutation entropy is a useful forensic tool for identifying sections of data that require targeted re-analysis---and can even be useful in guiding that analysis.Comment: 15 pages, 7 figure

Sequential non-rigid structure from motion using physical priors

© 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.We propose a new approach to simultaneously recover camera pose and 3D shape of non-rigid and potentially extensible surfaces from a monocular image sequence. For this purpose, we make use of the Extended Kalman Filter based Simultaneous Localization And Mapping (EKF-SLAM) formulation, a Bayesian optimization framework traditionally used in mobile robotics for estimating camera pose and reconstructing rigid scenarios. In order to extend the problem to a deformable domain we represent the object's surface mechanics by means of Navier's equations, which are solved using a Finite Element Method (FEM). With these main ingredients, we can further model the material's stretching, allowing us to go a step further than most of current techniques, typically constrained to surfaces undergoing isometric deformations. We extensively validate our approach in both real and synthetic experiments, and demonstrate its advantages with respect to competing methods. More specifically, we show that besides simultaneously retrieving camera pose and non-rigid shape, our approach is adequate for both isometric and extensible surfaces, does not require neither batch processing all the frames nor tracking points over the whole sequence and runs at several frames per second.Peer ReviewedPostprint (author's final draft

Instructional variables involved in problems associated with diglossia in Arabic speaking schools in Israel. PIRLS 2006 findings

PIRLS 2006 findings establish that reading literacy attainments of 4th graders in Arabic-speaking countries are poor. This low attainment is also reflected in the findings of PIRLS 2006 in Israel when comparing Arabic-speaking 4th graders\u27 reading literacy mean score with that of their Hebrew-speaking peers (428 vs. 528). Findings of a previous study (Zuzovsky, 2008) supported an explanation that the existence of diglossia typical of the Arabic language (two linguistic codes - written and spoken) is the main cause of the low results of Arabic-speaking students in Israel and recommended educational interventions aimed to directly treat the problems of diglossia. Following these recommendations the present study aims to identify specific instructional activities that are significant in the effort to overcome the problems associated with Arabic diglossia. Of fourteen reading literacy activities positively associated with reading attainment, six exhibited significant interaction effects with the ethnic group variable indicating their relatively higher contribution to the achievement of students in Arabic-speaking schools. The most effective variables for Arabic-speaking students appear to be those indicating early home literacy activities that foster phonemic awareness and letter sound recognition. Among the school literacy activities, repeated listening to the sounds of written Arabic and being actively engaged in reading text and gradually in more challenging tasks, are promising school practices. (DIPF/Orig.)Bei PIRLS 2006 zeigen die Viertklässler in arabischsprachigen Ländern nur schwache Leseleistungen. Diese geringen Leistungswerte lassen sich auch in den israelischen PIRLS 2006-Resultaten nachweisen, wenn man dort den Leistungsmittelwert der arabischsprechenden Viertklässler mit dem ihrer hebräischsprechenden Mitschüler vergleicht (428 vs. 528 Skalenpunkte). Ergebnisse einer früheren Studie (…) unterstützen einen Erklärungsansatz, dem zufolge die für die arabische Sprache typische Diglossie (zwei unterschiedliche linguistische Codes für geschriebene und gesprochene Sprache) der Hauptgrund für die geringen Leistungswerte der arabischsprechenden Schüler in Israel ist. Diese Studie empfiehlt pädagogische Interventionen, die direkt auf die mit Diglossie verbundenen Probleme wirken sollen. Die vorliegende Studie folgt diesen Empfehlungen und zielt darauf ab, diejenigen spezifischen Unterrichtsaktivitäten zu identifizieren, die sich bei dem Bemühen, die mit arabischer Diglossie verbundenen Probleme zu überwinden, als signifikant herausstellen. Von 14 Leseaktivitäten, die mit positiven Auswirkungen auf die Leseleistung verbunden sind, zeigen 5 einen signifikanten Interaktionseffekt mit der Variable der ethnischen Gruppenzugehörigkeit, was auf ihren relativ gesehen höheren Beitrag zu der Leseleistung in arabischsprachigen Schulen hindeutet. Die Variablen mit dem großen leseförderlichen Effekt für arabischsprachige Schüler scheinen Aktivitäten früher Leseförderung in den Elternhäusern zu sein, die sich auf phonemische Bewusstheit und auf das Erkennen von Buchstaben und Lauten beziehen. Zu den schulischen Leseaktivitäten, die sich als vielversprechend erweisen, zählen das wiederholte Anhören von Lauten der geschriebenen arabischen Sprache und ein aktives Eingebundensein in das Lesen von Texten und zunehmend anspruchsvollere Leseaufgaben. (DIPF/Orig.

The developmental effects of media-ideal internalization and self-objectification processes on adolescents’ negative body-feelings, dietary restraint, and binge eating

Despite accumulated experimental evidence of the negative effects of exposure to media-idealized images, the degree to which body image, and eating related disturbances are caused by media portrayals of gendered beauty ideals remains controversial. On the basis of the most up-to-date meta-analysis of experimental studies indicating that media-idealized images have the most harmful and substantial impact on vulnerable individuals regardless of gender (i.e., “internalizers” and “self-objectifiers”), the current longitudinal study examined the direct and mediated links posited in objectification theory among media-ideal internalization, self-objectification, shame and anxiety surrounding the body and appearance, dietary restraint, and binge eating. Data collected from 685 adolescents aged between 14 and 15 at baseline (47 % males), who were interviewed and completed standardized measures annually over a 3-year period, were analyzed using a structural equation modeling approach. Results indicated that media-ideal internalization predicted later thinking and scrutinizing of one’s body from an external observer’s standpoint (or self-objectification), which then predicted later negative emotional experiences related to one’s body and appearance. In turn, these negative emotional experiences predicted subsequent dietary restraint and binge eating, and each of these core features of eating disorders influenced each other. Differences in the strength of these associations across gender were not observed, and all indirect effects were significant. The study provides valuable information about how the cultural values embodied by gendered beauty ideals negatively influence adolescents’ feelings, thoughts and behaviors regarding their own body, and on the complex processes involved in disordered eating. Practical implications are discussed