Die vorliegende Dissertation ist in der empirischen Bildungsforschung angesiedelt und beschäftigt sich mit der Erfassung sprachlicher Kompetenzen im Deutschen. Dabei werden sowohl methodische als auch didaktische Überlegungen angestellt und empirische Befunde präsentiert, die sich auf Analysen zu den Bildungsstandards im Fach Deutsch für den Primarbereich beziehen. Die Dissertation umfasst vier empirische Beiträge, die von einer integrierenden Rahmung umschlossen werden. Der erste empirische Beitrag mit dem Titel „Zur Abgrenzung des Hörverstehens gegenüber dem Leseverstehen mit Hilfe schwierigkeitsbestimmender Merkmale bei der Entwicklung von Testaufgaben“ thematisiert die Operationalisierung des Hörverstehens im Rahmen von Large-Scale Assessments und analysiert schwierigkeitsbestimmende Merkmale in bildungsstandardbasierten Testaufgaben. Der zweite empirische Beitrag trägt den Titel „Aspekte der Kodierung von Schreibaufgaben“ und widmet sich diagnostischen Fragen der Operationalisierung der Schreibkompetenz und der Bewertung von Schreibprodukten. Neben einer Analyse der Interraterreliabilität werden zwei Kodierstrategien miteinander vergleichen und hinsichtlich ihrer Eignung in Large-Scale Assessments untersucht. Der dritte empirische Beitrag mit dem Titel „Diagnostik der Rechtschreibkompetenz in der Grundschule – Konstruktprüfung mittels Fehler- und Dimensionsanalysen“ befasst sich mit der Evaluierung der Rechtschreibkompetenz und wählt hierfür einen diagnostischen Ansatz, der sowohl quantitative Aussagen über das globale Kompetenzniveau als auch Aussagen auf der Ebene von qualitativen Fehleranalysen gestattet. Der vierte empirische Beitrag trägt den Titel „Methodische Aspekte der Erfassung der Lesekompetenz“ und beleuchtet messmethodische Herausforderungen bei der testdiagnostischen Erfassung und Modellierung der Lesekompetenz. / This doctoral dissertation is based in the field of educational science and explores the assessment of language abilities in German. In my thesis, I address both measurement aspects and didactical considerations in language assessment and present the empirical results of analyses of the National Education Standards for German language at the elementary school level. The thesis consists of four empirical articles and is embedded in a theoretical framework. The first article, entitled “On the distinction of listening and reading comprehension with the help of characteristics that affect item difficulty”, focuses on the Large-Scale-Assessment of listening comprehension and presents results of the analyses of the effect of item characteristics on item difficulty in the development of standards-based assessment tasks. The second article, entitled “Issues of the evaluation of writing”, explores aspects of writing assessment and different evaluation procedures for writing products. An investigation of inter-rater-reliability, as well as a comparison between analytic and holistic coding is conducted and the practicality of both strategies in Large-Scale-Assessment is discussed. The third article, entitled “The assessment of orthographic competence at elementary level – an evaluation of dimensionality”, focuses on the study of orthographic competency as defined by the National Educational Standards. The analyses combine quantitative analyses of the general level of competence, as well as qualitative error-analyses at the orthographic level. The fourth article, entitled “Methodological aspects of reading assessment”, illustrates methodological challenges in testing and modeling reading comprehension. The content of this article is twofold: On the one hand, it examines methodological means to identify the dimensionality of constructs and on the other hand, it addresses differential item functioning in groups with dissimilar levels of competency.

Ein Vierteljahrhundert nach der Wiedervereinigung Deutschlands gibt es zwischen Ost- und Westdeutschland nach wie vor differierende Anteile von Personen, die eine schulische Hochschulzugangsberechtigung erlangen und diese anschließend durch den Übergang an eine Hochschule einlösen. Mittels eines selbst entwickelten Modells, das sich an die soziologische Wert-Erwartungs-Theorie von Erikson & Jonsson sowie den lebensverlaufstheoretischen Ansatz von Mayer anlehnt, werden verschiedene individuelle und kontextuelle Einflussfaktoren der Studienentscheidung erstmals in einem Kohortenvergleich seit 1990 betrachtet. Neben der Schwelle Hochschulzugang werden zudem erstmals die Bildungsverläufe von zwei Studienberechtigtenkohorten in ihrer Gesamtheit, also unter Berücksichtigung von Fortbildung, Erwerbs- und Familienverläufen über einen Zeitraum von zehneinhalb Jahren vergleichend in den Blick genommen und mittels Sequenzmusteranalysen jeweils typische Verlaufsmuster für ost- und westdeutsche Studienberechtigte ermittelt. Zur Untersuchung der zentralen Forschungsfrage nach Konvergenzen, Divergenzen und dauerhaften Unterschieden in den individuellen und kontextuellen Einflussfaktoren der Studienentscheidung sowie den nachschulischen Bildungsverläufen seit 1990 in Ost- und Westdeutschland werden Daten der DZHW-Studienberechtigtenpanel 1990, 1994, 1999, 2002 und 2006 verwendet. Zusammenfassend werden zahlreiche Konvergenzen und Gemeinsamkeiten identifiziert, insbesondere bei den individuellen Einflussfaktoren für eine Studienentscheidung. Charakteristische Ost-West-Unterschiede zeigen sich u.a. bei der Bedeutung der bisherigen Bildungsbiografie und der antizipierten Studienkosten für die Studienentscheidung sowie der Hochschulentfernung. Die nachschulischen Bildungs- und Lebensverläufe weisen bereits bei der Kohorte 1990 erhebliche Gemeinsamkeiten auf. Bei der Kohorte 1999 haben sich neue Unterschiede bei der Bedeutung von Arbeitslosigkeit und Familientätigkeit herausgebildet. / A quarter of a century has passed since the reunification of Germany. The proportion of young people who acquire a university entrance qualification and those who attend university subsequently differ in part considerably between East and West Germany. This survey examines different individual and contextual factors, which influence the decision to attend university, for the first time by contrasting cohorts since 1990, using a specifically developed model, which closely follows the rational choice model by Erikson & Jonsson and the life-course theory approach by Mayer. The transition to a university is one threshold in the complete educational after-school career. Therefore, the educational careers of two cohorts entitled to study are for the first time examined as a whole, regarding further training, as well as occupational trajectories and family development over a period of ten and a half years after schooldays; by means of sequence pattern analyses, typical sequential patterns of school leavers from East and respectively West Germany are identified. For the examination of the central research question concerning convergences, divergences and permanent differences with regard to the individual and contextual factors, which have influenced study decisions and after-school educational careers since 1990 in East and West Germany, this investigation uses data from the DZHW panels about persons entitled to study from 1990, 1994, 1999, 2002, and 2006. To sum up, numerous convergences and commonalities can be identified, especially regarding the individual factors, which influence the decision to attend university. But typical East-West differences appear with regard to the importance of the previous educational career and the anticipated costs to study, but also the distance of university. The after-school educational and life courses have already many common features in the cohort from 1990. New differences have developed in the cohort from 1999.

Ausgehend vom Rahmenmodell zur Persönlichkeitsentwicklung von Schüler/inne/n nach Pekrun/Helmke (1991), der „Eingrenzungs- und Kompromisstheorie der Berufswahl“ von Gottfredson (2005) und der Typologie des Aufbaus von Berufsidentitäten Fends (1991) wird der Berufsfindungsprozess von Schüler/inne/n der Grundschule (Kl. 5) bis in die Sekundarstufe (Kl. 9) untersucht. Analysiert werden die Berufswünsche von 600 bis 3000 Befragten und ausgewählte Variablen des längsschnittlichen Datensatzes der DFG-Projekte NOVARA, SABA und AIDA (geleitet von Prof. Dr. Renate Valtin). Es werden zwei Fragestellungen verfolgt: (1) Ist die Berufswahltheorie von Gottfredson geeignet, empirisch verifiziert die früh zu beobachtende geschlechtsspezifische Weichenstellungen in der beruflichen Orientierung fundiert zu erklären? (2) Lassen sich Zusammenhänge zwischen einer krisenhaften Bewältigung der Entwicklungsaufgabe „Berufswahl“ und der Entwicklung ausgewählter schulleistungsrelevanter Persönlichkeitsmerkmale nachweisen? Wenn ja, ab wann? Die Analysen bestätigten die Forschungsbefunde zur Geschlechtstypik der beruflichen Interessenorientierung, zum Wandel vom „Traumberuf“ zum realistischen Berufswunsch sowie zu Schwankungen der Häufigkeit geäußerter Berufswünsche in Abhängigkeit von Klassenstufe und Schulform. Des Weiteren bestätigte sich die in der Berufswahltheorie von Gottfredson beschriebene Bedeutung der Kategorie „Geschlecht“ für die Präferenz bestimmter Berufswünsche, des noch akzeptierten Prestiges der Berufswünsche und des mit der Realisierung und Ausübung des gewünschten Berufs verbundenen noch zu bewältigenden kognitiven Anspruchs. Zusammenhänge zwischen der Entwicklung schulleistungsrelevanter Persönlichkeitsmerkmale ab dem Grundschulalter und einer krisenhaften Bewältigung der Entwicklungsaufgabe „Entwicklung einer beruflichen Orientierung“ in der Sekundarstufe I konnten in Bezug auf die allgemeine Schulfreude der männlichen Befragten nachgewiesen werden. / Based on Rahmenmodell zur Persönlichkeitsentwicklung von Schüler/inne/n by Pekrun and Helmke (1991), "Eingrenzungs- und Kompromisstheorie der Berufswahl" Gottfredson (2005) and Typologie des Aufbaus von Berufsidentitäten Fends (1991), the career choice process of primary school students (Class 5) to secondary school (Class 9) is examined longitudinally. The career desires of 600 to 3000 subjects are examined longitudinally, along with selected variables of the longitudinal dataset from the DFG projects NOVARA, SABA and AIDA (led by Prof. Dr. Renate Valtin). Two questions are considered: (1) is the ''Circumscription und Compromise Theory'' according to Gottfredson suitable for explaining the empirically verified gender-specific directions in career orientation, which can be observed early, on a theoretical basis? (2) Can interconnections between a critical mastering of the development task "career selection" and the development of selected school performance-related personality attributes be demonstrated? If yes, from when? Analyses confirm the gender-specification of career orientation, about the change from "dream job" to realistic career choice and about the fluctuations in frequency of stated career desires depending on school year and type of school. Moreover, the importance of the category "gender" described in the "circumscription and compromise theory" of career choice by Gottfredson is confirmed for the preference of certain career desires, of the still accepted prestige of the career desires and of the cognitive requirement yet to be mastered in conjunction with the realisation and exercise of the desired profession. Connections between the development of school performance-relevant personality attributes from primary school age and a critical mastering of the development task "development of a career orientation" in Sekundarstufe I (equivalent to Key Stage 3) could be demonstrated with regard to general happiness at school of the male subjects.

Efforts to reduce vehicle weight and improve crash performance have resulted in increased application of advanced high strength steels (AHSS) and a recent focus on the weldability of these alloys. Resistance spot welding (RSW) is the primary sheet metal welding process in the manufacture of automotive assemblies. Integration of AHSS into the automotive architecture has brought renewed challenges for achieving acceptable welds. The varying alloying content and processing techniques has further complicated this initiative. The current study examines resistance spot welding of high strength and advance high strength steels including high strength low alloy (HSLA), dual phase (DP) and a ferritic-bainitic steel (590R). The mechanical properties and microstructure of these RSW welded steel alloys are detailed. Furthermore a relationship between chemistries and hardness is produced. The effect of strain rate on the joint strength and failure mode is also an important consideration in the design of welded structures. Current literature, however, does not explain the effects of weld microstructure and there are no comprehensive comparisons of steels. This work details the relationship between the joint microstructure and impact performance of spot welded AHSS. Quasi-static and impact tests were conducted using a universal tensile tester and an instrumented drop tower, respectively. Results for elongation, failure load and energy absorption for each material are presented. Failure modes are detailed by observing weld fracture surfaces. In addition, cross-sections of partially fractured weldments were examined to detail fracture paths during static loading. Correlations between the fracture path and mechanical properties are developed using observed microstructures in the fusion zone and heat-affected-zone. Friction stir spot welding (FSSW) has proven to be a potential candidate for spot welding AHSS. A comparative study of RSW and FSSW on spot welding AHSS has also been completed. The objective of this work is to compare the microstructure and mechanical properties of Zn-coated DP600 AHSS (1.2mm thick) spot welds conducted using both processes. This was accomplished by examining the metallurgical cross-sections and local hardnesses of various spot weld regions. High speed data acquisition was also used to monitor process parameters and attain energy outputs for each process.

Efforts to reduce vehicle weight and improve crash performance have resulted in increased application of advanced high strength steels (AHSS) and a recent focus on the weldability of these alloys. Resistance spot welding (RSW) is the primary sheet metal welding process in the manufacture of automotive assemblies. Integration of AHSS into the automotive architecture has brought renewed challenges for achieving acceptable welds. The varying alloying content and processing techniques has further complicated this initiative. The current study examines resistance spot welding of high strength and advance high strength steels including high strength low alloy (HSLA), dual phase (DP) and a ferritic-bainitic steel (590R). The mechanical properties and microstructure of these RSW welded steel alloys are detailed. Furthermore a relationship between chemistries and hardness is produced. The effect of strain rate on the joint strength and failure mode is also an important consideration in the design of welded structures. Current literature, however, does not explain the effects of weld microstructure and there are no comprehensive comparisons of steels. This work details the relationship between the joint microstructure and impact performance of spot welded AHSS. Quasi-static and impact tests were conducted using a universal tensile tester and an instrumented drop tower, respectively. Results for elongation, failure load and energy absorption for each material are presented. Failure modes are detailed by observing weld fracture surfaces. In addition, cross-sections of partially fractured weldments were examined to detail fracture paths during static loading. Correlations between the fracture path and mechanical properties are developed using observed microstructures in the fusion zone and heat-affected-zone. Friction stir spot welding (FSSW) has proven to be a potential candidate for spot welding AHSS. A comparative study of RSW and FSSW on spot welding AHSS has also been completed. The objective of this work is to compare the microstructure and mechanical properties of Zn-coated DP600 AHSS (1.2mm thick) spot welds conducted using both processes. This was accomplished by examining the metallurgical cross-sections and local hardnesses of various spot weld regions. High speed data acquisition was also used to monitor process parameters and attain energy outputs for each process.

In this study, the spin-splitting energy of the lowest conduction bands in bulk zincblende and wurtzite structures of III-V semiconductors had been investigated by the linear combination of atomic orbital (LCAO) method, the atomic bond-orbital model (ABOM), and the two-band k¡Dp (2KP) model. Spin-splitting calculation for zincblende structures: We develop a 16-band atomic bond-orbital model (ABOM) to compute the spin splitting induced by bulk inversion asymmetry in zincblende materials. This model is derived from the linear combination of atomic orbital (LCAO) scheme such that the characteristics of the real atomic orbitals can be preserved to calculate the spin splitting. The Hamiltonian of 16-band center-zone ABOM (CZABOM) is based on a similarity transformation performed on the nearest-neighbor LCAO Hamiltonian with a second-order Taylor expansion over k at the £F point. The spin-splitting energies in bulk zincblende semiconductors, GaAs and InSb, are calculated, and the results agree with the LCAO and first-principles calculations. However, we find that the spin-orbit coupling between bonding and antibonding p-like states, evaluated by the 16CZABOM, dominates the spin splitting of the lowest conduction bands in the zincblende materials. Spin-splitting calculation for wurtzite structures: The spin-splitting energies in biaxially strained bulk wurtzite material AlN are calculated using the linear combination of atomic orbital (LCAO) method, and the equi-spin-splitting distributions in k-space near the minimum-spin-splitting (MSS) surfaces are illustrated. These data are compared with those derived analytically by two-band k¡Dp (2KP) model. It is found that the results from these two methods are in good agreement for small k. However, the ellipsoidal MSS surface under biaxial compressive strain does not exist in the 2KP model, because the data points are far from the £F point. Instead, three basic shapes of the MSS surface occur in the wurtzite Brillouin zone: a hyperboloid of two sheets, a hexagonal cone, and a hyperboloid of one sheet, evaluated from the LCAO method across the range of biaxial strains from compressive to tensile. The shapes of the equi-spin-splitting (ESS) surfaces near these MSS surfaces have also three types: a hyperboloid of one sheet, an approximate, asymmetric hyperboloid surface, and an opposing hyperboloid of one sheet.

<p>This study examined three schools / namely a Public, Ex model C, and a Youth juvenile rehabilitation school. A non-experimental survey design was used for this study. The sample consisted of 47 educators across the three types of schools. Data was collected by means of two instruments: a demographic questionnaire, and the Maslach Burnout Inventory (MBI) consisting of three subscales namely / Emotional Exhaustion, Depersonalization, and Diminished Personal Accomplishment. It was hypothesised that due to the stressful nature of work in disadvantaged and resource lacking schools, as well as the unstable and unsafe environment in certain schools, burnout among educators in Public and Youth juvenile rehabilitation schools will have a higher prevalence rate than educators in Ex model C schools. The study also aimed to identify which various educator demographic variables correlate with high burnout levels. Correlational results of the study found no significant relationships between the three subscales of the MBI and certain educator demographic variables across the three types of schools. The results of an Analysis of Variance (ANOVA) test revealed a borderline non-significant difference in the Emotional Exhaustion subscale between the Youth juvenile rehabilitation school and Public schools. Post Hoc comparison tests suggested Public school educators in the sample had the highest levels of burnout in terms of Emotional Exhaustion across the three types of schools, while educators in the Youth juvenile rehabilitation schools showed the lowest levels of burnout in terms of Emotional exhaustion. The results of the present study were discussed from the perspective of the Conservation of Resources theory, suggesting resource depletion as a central facet to burnout and how prolonged stress leads to burnout. Future qualitative studies exploring the etiology of burnout was thus recommended.</p>

Magister Psychologiae - MPsych / This study examined three schools; namely a Public, Ex model C, and a Youth juvenile rehabilitation school. A non-experimental survey design was used for this study. The sample consisted of 47 educators across the three types of schools. Data was collected by means of two instruments: a demographic questionnaire, and the Maslach Burnout Inventory (MBI) consisting of three subscales namely; Emotional Exhaustion, Depersonalization, and Diminished Personal Accomplishment. It was hypothesised that due to the stressful nature of work in disadvantaged and resource lacking schools, as well as the unstable and unsafe environment in certain schools, burnout among educators in Public and Youth juvenile rehabilitation schools will have a higher prevalence rate than educators in Ex model C schools. The study also aimed to identify which various educator demographic variables correlate with high burnout levels. Correlational results of the study found no significant relationships between the three subscales of the MBI and certain educator demographic variables across the three types of schools. The results of an Analysis of Variance (ANOVA) test revealed a borderline non-significant difference in the Emotional Exhaustion subscale between the Youth juvenile rehabilitation school and Public schools. Post Hoc comparison tests suggested Public school educators in the sample had the highest levels of burnout in terms of Emotional Exhaustion across the three types of schools, while educators in the Youth juvenile rehabilitation schools showed the lowest levels of burnout in terms of Emotional exhaustion. The results of the present study were discussed from the perspective of the Conservation of Resources theory, suggesting resource depletion as a central facet to burnout and how prolonged stress leads to burnout. Future qualitative studies exploring the etiology of burnout was thus recommended. / South Africa

This thesis discusses the possibility of ensuring the safety, integrity and authenticity of data communication with respect to user privacy. This thesis describes the fundamentals of smart grid networks with capabilities of existing forms of security to communications that have been chosen as a target for application deployment of group signatures to ensure the security, integrity and authenticity of data communications. It describes the concept of a zero-knowledge and cryptography primitives. Further, the basic principles are presented, the history of development, and various schemes are compared based on the construction and performance. The second part is given to the deployment and optimization of group signatures for computationally limited devices. Within the draft report were to be implemented in the Java language chosen scheme HLCCN, DP and BBS. They were then tested under various platforms which were measured and evaluated performance parameters of the schemes. The optimization of the work is focused on the times of signatures, which are critical to a smart grid system. Under the platforms are deployed pre-processed pairing optimization methods and other methods resulting from the deployment platform as JPBWrappera and native libraries to deliver more efficient times of sgnaiture. At the end of the thesis are evaluated achievements of optimization methods and the appropriateness of the deployment of smart grids.

No description available.