Reversible ferromagnetic switching in ZnO:(Co,Mn) powders

We report here on the magnetic properties of ZnO:Mn- and ZnO:Co-doped nanoparticles. We have found that the ferromagnetism of ZnO:Mn can be switched on and off by consecutive low-temperature annealings in O2 and N2, respectively, while the opposite phenomenology was observed for ZnO:Co. These results suggest that different defects (presumably n-type for ZnO:Co and p-type for ZnO:Mn) are required to induce a ferromagnetic coupling in each case. We will argue that ferromagnetism is likely to be restricted to a very thin, nanometric layer at the grain surface. These findings reveal and give insight into the dramatic relevance of surface effects to the occurrence of ferromagnetism in ZnO-doped oxides.

Speech sample estimation from composite zerocrossings and encoding via adaptive switching of transforms

This thesis investigates the potential use of zerocrossing information for speech sample estimation. It provides 21 new method tn) estimate speech samples using composite zerocrossings. A simple linear interpolation technique is developed for this purpose. By using this method the A/D converter can be avoided in a speech coder. The newly proposed zerocrossing sampling theory is supported with results of computer simulations using real speech data. The thesis also presents two methods for voiced/ unvoiced classification. One of these methods is based on a distance measure which is a function of short time zerocrossing rate and short time energy of the signal. The other one is based on the attractor dimension and entropy of the signal. Among these two methods the first one is simple and reguires only very few computations compared to the other. This method is used imtea later chapter to design an enhanced Adaptive Transform Coder. The later part of the thesis addresses a few problems in Adaptive Transform Coding and presents an improved ATC. Transform coefficient with maximum amplitude is considered as ‘side information’. This. enables more accurate tfiiz assignment enui step—size computation. A new bit reassignment scheme is also introduced in this work. Finally, sum ATC which applies switching between luiscrete Cosine Transform and Discrete Walsh-Hadamard Transform for voiced and unvoiced speech segments respectively is presented. Simulation results are provided to show the improved performance of the coder

Service provider switching: a study on the switching process in retail banking

In a business environment that is characterized by intense competition, building customer loyalty has become a key area of focus for most financial institutions. The explosion of the services sector, changing customer demographics and deregulation and emergence of new technology in the financial services industry have had a critical impact on consumers’ financial services buying behaviour. The changes have forced banks to modify their service offerings to customers so as to ensure high levels of customer satisfaction and also high levels of customer retention. Banks have historically had difficulty distinguishing their products from one another because of their relative homogeneity; with increasing competition,the problem has only intensified with no coherent distinguishing theme. Rising wealth, product proliferation, regulatory changes and newer technologies are together making bank switching easier for customers. In order to remain competitive, it is important for banks to retain their customer base. The financial services sector is the foundation for any economy and plays the role of mobilization of resources and their allocation. The retail banking sector in India has emerged as one of the major drivers of the overall banking industry and has witnessed enormous growth. Switching behaviour has a negative impact on the banks’ market share and profitability as the costs of acquiring customers are much higher than the costs of retaining. When customers switch, the business loses the potential for additional profits from the customer the initial costs invested in the customer by the business get . The Objective of the thesis was to examine the relationship among triggers that customers experience, their perceptions of service quality, consumers’ commitment and behavioral intentions in the contemporary India retail banking context through the eyes of the customer. To understand customers’ perception of these aspects, data were collected from retail banking customers alone for the purpose of analysis, though the banks’ views were considered during the qualitative work carried out prior to the main study. No respondent who is an employee of a banking organization was considered for the final study to avoid the possibility of any bias that could affect the results adversely. The data for the study were collected from customers who have switched banks and from those who were non switchers. The study attempted to develop and validate a multidimensional construct of service quality for retail banking from the consumer’s perspective. A major conclusion from the empirical research was the confirmation of the multidimensional construct for perceived service quality in the banking context. Switching can be viewed as an optimization problem for customers; customers review the potential gains of switching to another service provider against the costs of leaving the service provider. As banks do not provide tangible products, their service quality is usually assessed through service provider’s relationship with customers. Thus, banks should pay attention towards their employees’ skills and knowledge; assessing customers’ needs and offering fast and efficient services.

All-Optical Label Stacking: Easing the Trade-offs Between Routing and Architecture Cost in All-Optical Packet Switching

All-optical label swapping (AOLS) forms a key technology towards the implementation of all-optical packet switching nodes (AOPS) for the future optical Internet. The capital expenditures of the deployment of AOLS increases with the size of the label spaces (i.e. the number of used labels), since a special optical device is needed for each recognized label on every node. Label space sizes are affected by the way in which demands are routed. For instance, while shortest-path routing leads to the usage of fewer labels but high link utilization, minimum interference routing leads to the opposite. This paper studies all-optical label stacking (AOLStack), which is an extension of the AOLS architecture. AOLStack aims at reducing label spaces while easing the compromise with link utilization. In this paper, an integer lineal program is proposed with the objective of analyzing the softening of the aforementioned trade-off due to AOLStack. Furthermore, a heuristic aiming at finding good solutions in polynomial-time is proposed as well. Simulation results show that AOLStack either a) reduces the label spaces with a low increase in the link utilization or, similarly, b) uses better the residual bandwidth to decrease the number of labels even more

Effect of arousal increase in predictable and random task switching : Evidence for the involvement of the anterior attentional network in random but not in predictable task switching

Resumen tomado de la publicaci??n

Análisis del comportamiento de la inflación trimestral en Colombia bajo cambios de régimen: Una evidencia a través del modelo "Switching" de Hamilton.

Este trabajo tiene como propósito estudiar la evolución de la inflación trimestral en Colombia, durante el período comprendido entre 1954 y 1996, a través de la metodología de Hamilton(1989) y segundo presentar algunos conceptos relacionados con dicha metodología, la cual introduce cambios de régimen en el análisis convencional de series de tiempo. En general, esta metodología permite estimar modelos ARIMA con parámetros o varianzas cambiantes en el tiempo. En este caso, tales cambios en el modelo de la inflación se suponen asociados a posibles regímenes distintos donde la inflación presenta cambios en su nivel o en su variabilidad. Esta modelación posibilita el reconocimiento de los distintos regímenes a través del tiempo (por ejemplo dos regímenes: inflación alta e inflación baja) en lo referente a su tiempo promedio de duración y a la probabilidad asociada de cada uno de ellos, es decir, la probabilidad de estar en un régimen particular en un momento dado del tiempo. Las probabilidades de transición estimadas, permiten concluir, por ejemplo, que al estar en un régimen de inflación trimestral moderado, la probabilidad de permanecer en éste es muy alta (0.94), en tanto que pasar de éste a un régimen de inflación promedio alta tiene una probabilidad de (0.05), la cual es cinco veces mayor que la estimada para la transición de moderada a baja (0.01). Adicionalmente, se puede observar que la máxima probabilidad de permanecer en un mismo régimen se tiene en aquel caracterizado como de inflación y variabilidad moderadas.

Habilidades sociales y estrategias de aprendizaje en alumnos universitarios : efectos del entrenamiento sobre el rendimento y otras variables psicoeducativas.

Aportar procedimientos de entrenamiento en habilidades sociales y en estrategias de aprendizaje para alumnos de Magisterio. Validar el modelo de intervención psicoeducativa de Román y revisar los conocimientos disponibles sobre estos dos constructos. Estudiantes de segundo curso de Magisterio de Tarragona, de 20 años de edad, de población rural y en su mayoría de clase media y bilingües. Plantea un marco teórico y las hipótesis de trabajo. Variables independientes: entrenamiento en habilidades sociales y estrategias de aprendizaje. Variables dependientes: rendimiento académico y variables psicoeducativas medidas a través de tests estandarizados. Utiliza un diseño quasi-experimental de tipo factorial 2x2. Asigna la muestra a cuatro grupos aleatoriamente. Realiza un estudio de las habilidades sociales más requeridas para hacer frente a las situaciones problemáticas por parte de los alumnos. Realiza una prueba piloto de las pruebas y pasa a las fases de pretest, intervención, postest y seguimiento de los resultados obtenidos. Cuestionario de habilidades sociales de Segura. Cuestionario de motivación y ansiedad de ejecución de Palechano. Escala de asertividad de Rathus. Cuestionario de autocontrol de Roserbaum. Escala de competencia académica percibida de Palenzuela. Inventario de hábitos de estudio para universitarios de Bernard. Cuestionario de autoconcepto de Fitts. Locus de control de Rotter. Estadísticos descriptivos, análisis de varianza para contrastar las hipótesis planteadas y paquete SPSS. Los efectos del entrenamiento se mantienen en el seguimiento en las variables de rendimiento académico (prácticas escolares) y variables de personalidad (locus control, dimensión externa). Los efectos más sensibles a corto plazo son en competencia académica percibida y locus de control, dimensión interna. Las variables estratégicas de estudio no son sensibles al entrenamiento. Los efectos se incrementan a largo plazo en: autoconcepto, autocontrol, habilidades sociales, asertividad, y en rendimiento académico en las asignaturas: psicopedagógicas, de especialidad y comunes. La predicción deducida del modelo de intervención psicoeducativa ha sido parcialmente contrastada por los datos, lo que permite seguir ajustando el modelo en sucesivos trabajos experimentales y/o correlacionales.

Atención a diversidade na Educación Secundaria de Galicia : perfís do alumnado con baixo rendimento escolar e propostas de intervención psicoeducativa. 'Atención a la diversidad en la enseñanza secundaria de Galicia : perfiles educacionales del alumnado con rendimiento académico bajo y propuestas de intervención psicoeducativa'.

Se hace un análisis de los perfiles educacionales más característicos de los alumnos de educación secundaria con niveles bajos de rendimiento escolar, referidos a aspectos relacionados con los recursos culturales y académicos de los alumnos en sus hogares, así como con las interacciones familiares, su emocionalidad, el autoconcepto, sus afectos, sus metas académicas, sus expectativas, habilidades cognitivas y sus niveles de comprensión lectora. Además se hace un estudio concreto de los estilos y patrones atribucionales causales de dichos alumnos y sus enfoques de aprendizaje dominantes. Se hace también una síntesis de las principales variables instruccionales del proceso de enseñanza/aprendizaje y relacionadas con la actividad del profesorado en el aula. Se elaboran unas propuestas de intervención psicoeducativa de atención a la diversidad con este alumnado de educación secundaria de Galicia con bajo nivel de rendimiento académico.

¿Puedo tener un code-switching? : codeswitching en estudiantes de doctorado enseñando cursos de español lengua extranjera.

Memoria de máster (Universidad de Texas, 2010). Resumen basado en el de la publicación

Ensino-aprendizagem da Matem??tica com recurso : a software educativo : atitudes e rendimento acad??mico dos alunos. 'Ense??anza-aprendizaje de las Matem??ticas con recurso : el software educativo : actitudes y rendimiento acad??mico de los alumnos'

Resumen tomado de la publicaci??n

Organização e planeamento do treino de hóquei em patins em equipa de alto rendimento : desenvolvimento do modelo de jogo

Orientador: Jorge Proença

Organização e planeamento do treino de hóquei em patins em equipa de alto rendimento: desenvolvimento das capacidades motoras

Orientador: Jorge Proença

Influência das estratégias de avaliação contínua no rendimento escolar dos alunos

A avaliação contínua é um importante instrumento à disposição do professor. O presente trabalho estuda a medida em que um conjunto de conteúdos ministrados no 10º ano do ensino secundário, acompanhados de procedimentos baseados na avaliação contínua, pode contribuir para melhorar o desempenho e a aprendizagem relativamente a quatro elementos químicos da tabela periódica, nomeadamente o oxigénio, o hidrogénio, o carbono e o azoto. O trabalho será realizado em três turmas do ensino secundário. Os conteúdos programáticos relativos à “Tabela periódica-organização dos elementos químicos” a desenvolver nas três turmas serão os mesmos, mas ministrados por duas docentes distintas. Em duas das turmas, e durante quatro aulas, serão elaborados pequenos testes no início de cada aula sobre a matéria lecionada na aula anterior, que serão recolhidos e classificados pela docente por forma a averiguar uma esperada evolução. Nestas turmas as aprendizagens relativas a estes testes serão avaliadas de forma contínua. Na outra turma, turma de controlo, o programa será tratado da forma tradicional. No final proceder-se-á ao tratamento dos dados recolhidos e à elaboração das conclusões e de possíveis recomendações.