Telling identities: In Search of an Analytic Tool for Investigating Learning as a Culturally Shaped Activity

In this article, we make an attempt to operationalize the notion of identity so as to justify the claim about its potential as an analytic tool for investigating learning. According to our definition, identity is a set of reifying, significant, endorsable stories about a person. The subsequent analysis of the dynamics of narratives makes it clear that identities, even if individually told, are products of a collective storytelling. Our main claim is that learning may be thought of as closing the gap between actual identity and designated identity, two particular sets of reifying significant stories about the learner, endorsed by this learner. The theoretical substantiation of this assertion is accompanied by vignettes from a study in which mathematical learning practices of a group of 17 year old immigrant students from the former Soviet Union newly arrived in Israel were compared to those of native Israelis

Premiums and Discounts in Business Valuation

Głównym celem artykułu jest ukazanie rodzajów i zasad stosowania korekt w wycenie przedsiębiorstw. Na podstawie literatury przedmiotu zaprezentowano wyniki badań dotyczące różnych koncepcji kalkulacji premii oraz dyskont, ich poziomów i czynników je kształtujących. Zaznaczono, iż podczas ich stosowania w wycenie spółki do każdego przypadku należy podchodzić indywidualnie i uwzględniać jego charakterystykę. W drugiej części opracowania przedstawiono wyniki badań przeprowadzonych na podstawie 1101 raportów finansowych, sporządzonych w latach 2009-2012 celem wydania rekomendacji dla spółek notowanych na Giełdzie Papierów Wartościowych w Warszawie. Ukazano rodzaje korekt, ich poziomy, a także uzasadnienia ich stosowania w procesie wyceny akcji.The main purpose of this paper is to present different types of adjustments and rules of applying them for the purpose of business valuation. On the basis of the literature review, various concepts of premium and discount calculation, along with their values and determinants on Polish and foreign markets, are shown. It is emphasized that any premium or discount must be individually adjusted to each case of business valuation. In the second part of the publication, the results of conducted survey are described. The sample consisted of 1,101 financial reports prepared in the years 2009-2012 to provide stock recommendations for the companies listed on the Warsaw Stock Exchange. Types and levels of premiums and discounts as well as causes of their application are [email protected] Błażej Prusak – Wydział Zarządzania i Ekonomii, Politechnika Gdańsk

Use of the PMD camera in mobile robotics for obstacle detection and obstacle avoidance as well as for self-localization

Diese Arbeit befasst sich mit der Hindernis- und Fahrwegerkennung, der Hindernisvermeidung sowie mit der Selbstlokalisierung eines mobilen Fahrzeugs. Während dafür bisher 2D-Laserscanner, 3D-Laserscanner oder Stereovision eingesetzt wurden, wird hier die Anwendung der PMD-Kamera gezeigt. Als Experimentierplattform wurde ein mobiler Roboter mit Differentialantrieb (Tom3D) und ein weiterer mobiler Roboter mit Ackermannantrieb (Merlin3D) vorgestellt. Beide mobilen Fahrzeuge sind mit der gleichen Systemarchitektur ausgestattet und besitzen je einen Embedded-PC für Sensordatenverarbeitung, Bildverarbeitung und Kommunikation sowie einen Mikrocontroller C167 für Geschwindigkeitsregelung und Hindernisvermeidung. Für die Geschwindigkeitsregelung und für die grobe Selbstlokalisierung kommen Rad-Encoder zum Einsatz. GPS- und Inklinations-sensoren dienen zur Unterstützung der Selbstlokalisierung. Der Zugriff auf das mobile Fahrzeug durch den Operator ist einerseits als manuelle Steuerung möglich oder kann andererseits per Wireless-LAN (WLAN) realisiert werden. Eine Telepräsenz bzw. Telemetrie via Mobilfunk oder Satellitenfunk ist denkbar. Eine PMD-Kamera zusammen mit einer 2D-Kamera wurde mit einem definierten Neigungswinkel in das mobile Fahrzeug integriert. Dabei wurden der Eindeutigkeitsbereich (7,5 m), der optische Öffnungswinkel und die Montagehöhe der PMD-Kamera berücksichtigt. Aus dieser Perspektive nimmt die PMD-Kamera stets Hindernisse und Fahrweg des Frontbereichs des mobilen Fahrzeugs insgesamt auf. Eine Unterscheidung zwischen Hindernissen und Fahrweg innerhalb des PMD-Videobildes ist notwendig. Auch muss zwischen sog. negativen und positiven Hindernissen differenziert werden. Für eine echtzeitfähige Separierung von Fahrweg, negativen und positiven Hindernissen müssen bei jedem PMD-Videobild der Neigungswinkel der PMD-Kamera sowie der Pitch- und der Roll-Winkel des mobilen Fahrzeugs berücksichtigt werden. Nach erfolgter Extrahierung der negativen und positiven Hindernisse wird das PMD-Videobild in gleich große vertikale Segmente unterteilt. Daraus wird das Segment (Segment-Nummer) ermittelt, welches die kleinste Distanz inne hat. Die Segment-Nummer und der minimale Distanzwert stellen die linguistischen Eingangsvariablen zweier Fuzzy-Logic-Reger dar. Nach der Fuzzifizierung folgt die Fuzzy-Inferenz, in der die Fahrmanöver zur Hindernisvermeidung linguistisch formuliert sind. Die daraus resultierenden Ergebnisse werden in der Defuzzifizierung schließlich in konkrete Motorsteuerungssignale umgesetzt. Mit Hilfe dieser Schritte ist eine Navigation ohne Umgebungskarte und ohne Pfad- bzw. Bahnregelung realisierbar. Das mobile Fahrzeug kann damit bereits für ungesteuertes Fahren bzw. Zufallsfahren für Explorationsaufgaben genutzt werden. Erst mit der Verfügbarkeit einer Selbstlokalisierung, hier speziell der relativen Selbst-lokalisierung und Koppelnavigation, sind Pfad- / Bahnfahren und Kartengenerierung möglich. Fahrbewegungen eines mobilen Fahrzeugs können durch Lageänderungen von Objekten bzw. deren markanten Merkmalen innerhalb der PMD-Videobildfolge einer PMD-Kamera beobachtet werden. Diese Lageänderungen gilt es stets innerhalb zweier aufeinander folgender PMD-Videobilder zu bestimmen. Proble-matisch dabei ist jedoch, die markanten Merkmale des ersten PMD-Videobildes im zweiten PMD-Videobild wieder zu finden und einander zuzuordnen. Aus diesen Lageänderungen können dann Translationsvektor und Rotationsmatrix bzw. die Poseänderung (Position und Orientierung) des mobilen Fahrzeugs errechnet werden. Markante Merkmale innerhalb der beteiligten PMD-Videobilder lassen sich u.a. mit Hilfe des sog. Moravec- bzw. Interest-Operators extrahieren. Die Korrespondenz-bildung zwischen beiden Merkmalspunktmengen kann nun mit Hilfe der Euklidischen Distanz bzw. der Euklidischen Norm erfolgen. Auf Basis dieser Paarbildungen können mittels der Einheitsquaternionen-Methode für 3D-Bewegungen oder mittels der HAYAI (Highspeed And Yet Accurate Indoor/outdoor-tracking) -Methode für 2D-Bewegungen nun die gesuchte Rotationsmatrix und anschließend der Translationsvektor bestimmt werden. Translationsvektor und Rotationsmatrix weisen Fehler auf, die mit Hilfe der ICP (Iterative Closest/Corresponding Points) -Methode iterativ verringert werden können. Einfache Fahrmanöver, Hinderniserkennung und -vermeidung, Selbstlokalisation, Pfad- / Bahnfahren, usw. lassen sich miteinander kombinieren und somit teilautonome Funktionen kreieren. Eine hierarchische Zusammenstellung zeigt den Übergang von reiner Fernsteuerung, über teilautonome und autonome Funktionen bis hin zu brauchbaren Dienstleistungen eines mobilen Fahrzeugs.The subject of this thesis is the obstacle and driveway recognition, the obstacle avoidance and the self-localization of a mobile vehicle. In the past therefore were used 2D, 3D laser scanner and stereo vision. This thesis shows the application of the PMD camera. As experimental platform was presented a mobile vehicle with differential drive (Tom3D) and another vehicle with Ackermann-drive (Merlin3D). Both mobile vehicles are equipped with the same system architecture, and each has an embedded PC for sensor data processing, image processing and communications, as well as a C167 microcontroller for speed control and obstacle avoidance. For the speed control and for a rough estimate of self-localization there are used wheel encoders. GPS and inclination sensors provide the self-localization. The access to such a mobile vehicle by the operator is possible as a manual control or can be realized by Wireless-LAN (WLAN). A tele-presence respectively telemetry is conceivable via mobile radio or satellite radio. A PMD camera and a 2D camera were integrated with a defined inclination angle onto the mobile vehicle. The unambiguity interval of 7.5 m, the optical field of view and the mounting height of the PMD-camera were considered. From this perspective, the PMD camera always records obstacles and driveway together in the front area of the mobile vehicle. There must be a differentiation between obstacles and the driveway within the PMD-video image. It also applies to differentiate between so-called negative and positive obstacles. For a real-time separation of driveway, negative and positive obstacles at every PMD video image must consider the inclination angle of the PMD-camera, as well as pitch and roll angle of the mobile vehicle. After successful extraction of the driveway and negative and positive obstacles inside the PMD-video image, it is divided into equal vertical segments. The segment (segment number) with the smallest distance will be selected. The segment number and the minimum distance value are the linguistic input variables for the Fuzzy-Logic-Controller. After the fuzzification of these values follows the fuzzy-inference, in this are the driving manoeuvres linguistically formulated for obstacle avoidance. Finally within the defuzzification the result data are converted into concrete motor control signals. With the help of these steps navigation is realizable without environment map and without path or driveway control. The mobile vehicle thereby can be already used for uncontrolled driving or random driving for tasks of exploration. Only with the availability of a self-localization, here specifically the relative self-localization, path driving and map generation are possible. Movements of a mobile vehicle can be observed by position changes of objects or their significant features within the continuous PMD image sequence of a PMD camera. These position changes must be determined within two sequential PMD video images. The problem is, however, to find the significant features of the first PMD video image again in the second PMD video image and assign them to each other. From these position changes the translation vector and rotation matrix respectively the pose change (position and orientation) of the mobile vehicle can be calculated. Significant features within the participating PMD-video images can be extracted with the help of the so-called Moravec- respectively Interest-operator. Now the correspondence between two feature point sets can be done by using the Euclidean distance respectively Euclidean norm. Based on these pairings, and by using the Unit-Quaternion-Method for 3D movements or by using the HAYAI-Method for 2D movements can be determined the desired rotation matrix and thereafter the translation vector. Translation vector and rotation matrix still have errors, which can be reduced iteratively by using the ICP-Method. Simple manoeuvres, obstacle detection, obstacle avoidance, self-localization, path driving, etc. can be combined with each other and thus create semi-autonomous functions. A hierarchical compilation will show the transition from pure remote control, via semi-autonomous and autonomous functions to useful services with the help of a mobile vehicle

Self-Regulation of Physical Education Teacher Education Students\u27 Attitudes Towards Exercise and Diet

The purpose of this study was to assess differences in self-regulation of attitudes towards engaging in exercise and eating a healthy diet between physical education teacher education (PETE) students and general education (GE) students, and between male students and female students. Participants were university students (n = 194) at a university in the Intermountain West in the U.S. Results showed that PETE students were more autonomous in their attitudes towards exercise than other students, all female students were more controlled in their attitudes towards diet than males, and PETE females’ attitudes towards diet were more controlled than PETE males. PETE curricula should include experiences to help students internalize exercise and healthy diet values so they will develop attitudes towards engaging in exercise and eating a healthy diet for autonomous reasons

Characteristics of the peanut chain in Europe – Implications for peanut allergy

Background. Peanuts are one of the main food allergens, occasionally responsible for life-threatening reactions. Thus, many studies have tried to find a connection between peanut allergy prevalence and processes in the peanut chain that may contribute to the peanut allergenicity. To inform this discussion, this paper outlines experiences in peanut cultivation, trade and processing in Europe, focusing on four European countries with different peanut experiences (Poland, Bulgaria, Spain and the UK). Material and method. Results here are based on documentary analysis and semi-structured, face-to-face interviews with 32 experts involved in various stages of the peanut chain, including peanut farmers, processors, traders, food technologists and manufacturers. Results. A common peanut chain diagram has been drawn considering shelled and in-shell peanuts. The analysis of each stage of peanut processing has been made in accordance with this peanut chain schema. Thermal and mechanical processes are discussed alongside the resultant end peanut products available for European consumers. The paper also analyses the main trends of peanut trade in Europe. The results suggest that the majority of peanut products in Europe are roasted, implying enhanced exposure of the population to more allergenic peanuts. Conclusion. The presented schema and related discussion bring together diverse aspects of peanut production, trade and processing. The main factor associated with the increased allergenicity of peanuts appears to be high temperature roasting. Frying and boiling are also thermal processes, but fried and boiled peanuts have been associated with reduce peanut allergenicity. Neither country of origin nor cultivar type appear to be related to differential peanut allergenicity. More research is needed as regards the impact of various additives, such as chocolate (which is also considered an allergen) on the allergenicity of peanut products. The use of peanuts in non-food products also needs more investigation.This project was funded by the EU via the EuroPrevall project (FOOD-CT-2005-514000

Pupils’ and teachers’ experiences of school-based physical education: A qualitative study

Objectives: To explore pupils’ and teachers’ experiences of P.E. Study Design: A qualitative investigation employing semi-structured interviews. Self Determination Theory was used as a guiding theory and Template Analysis was used to analyse the data. Setting: A secondary school in the North East of England. Participants: 14 pupils (aged 13 and 14, boys and girls) with a range of self-perceived competencies regarding P.E. and 4 P.E. teachers of the pupils (3 male, 1 female). Primary and secondary outcomes: (1) Attitudes and perceptions of P.E. pupils regarding their experiences of compulsory school P.E. lessons. (2) P.E. teachers experiences of teaching P.E. Results: Key results from pupils and teachers suggest pupils enjoy participation in P.E. when they feel competent, in control and supported by others. Feeling competent depended on i) the activity within P.E. and ii) the pupils perceived physical capabilities/aptitude. Feeling in control related to i) having a choice of activities, ii) being able to set exertion levels and iii) control over clothes worn whilst taking part. Relationships within pupil groups and between pupils and teachers were perceived as important. Teachers could positively influence their pupils’ enjoyment by understanding and supporting their personal goals, as opposed to dictating and controlling what they did and for how long, and by promoting a non-threatening atmosphere between pupils. Conclusions: Rising obesity levels and concerns over the fitness of children and young people has returned the focus of P.E. to its potential as a vehicle for promoting health. This study suggests schools and P.E. teachers in particular can positively influence the P.E. experience of both boys and girls by providing more choice of activities and letting pupils make their own decisions based on their personal needs

The Effects of the Type of Skill Test, Choice, and Gender on the Situational Motivation of Physical Education Students

The purpose of this study was to examine the effects of (a) skill test type, (b) choices, and (c) gender on the situational motivation profiles of adolescents during skill testing in physical education. Participants were 507 students (53% male) aged 12–16 years (M = 13.87; SD = 0.94) attending a suburban junior high school in a western state in the U.S. All participants experienced either a norm-referenced, summative or a criterion-referenced, formative skill test with or without choices. The Situational Intrinsic Motivation Scale (SIMS) was administered to assess situational motivation. A 2 (test type) × 2 (choice) × 2 (gender) MANOVA was used to test for significant differences on each of the four SIMS indices. Significant test type and gender and a significant test type by gender interaction were found. These findings suggest practitioners should use criterion-referenced, formative skill tests especially when teaching girls in physical education