Studies on Thermodynamics and No-hair Theorem in Black hole Spacetime

Department of Physics, Cochin University of Science and Technology

Prospects of sprayed CZTS thin film solar cells from the perspective of material characterization and device performance

This thesis is devoted to the development of a relatively new, rapidly developing quaternary semiconducting material (viz., Cu2ZnSnS4) used for photovoltaic applications. This semiconductor, commonly known as CZTS, is closely related to a family of materials that have been used for solar cell applications. It is a compound semiconductor made of copper, zinc, tin and sulfur, which are sufficiently abundant elements; none of them is harmful to the environment even at large scale usage. Aim of this study is to fabricate CZTS solar cells through chemical spray pyrolysis (CSP) technique. At first the influence of various spray parameters like substrate temperature, spray rate, precursor ratio etc. on the opto-electronic properties of CZTS films will be studied in detail. Then the fabrication of CZTS/In2S3 hetero junctions and various ways to improve the performance parameters will be tried

Length-weight relationship, relative condition factor (Kn) and morphometry of Arius subrostratus (Valenciennes, 1840) from a coastal wetland in Kerala

The length – weight relationship and relative condition factor of the shovel nose catfish, Arius subrostratus (Valenciennes, 1840) from Champakkara backwater were studied by examination of 392 specimens collected during June to September 2008. These fishes ranged from 6 to 29 cm in total length and 5.6 to 218 g in weight. The relation between the total length and weight of Arius subrostratus is described as Log W = -1.530+2.6224 log L for males, Log W = - 2.131 + 3.0914 log L for females and Log W = - 1.742 + 2.8067 log L for sexes combined. The mean relative condition factor (Kn) values ranged from 0.75 to 1.07 for males, 0.944 to 1.407 for females and 0.96 to 1.196 for combined sexes. The length-weight relationship and relative condition factor showed that the well-being of A. subrostratus is good. The morphometric measurements of various body parts and meristic counts were recorded. The morphometric measurements were found to be non-linear and there is no significant difference observed between the two sexes. From the present investigation, the fin formula can be written as D: I, 7; P: I, 12; A: 17 – 20; C: 26 – 32. There is no change in meristic counts with the increase in body length.

Didáctica del Francés lengua extranjera.

Contribuir al desarrollo armónico de la personalidad de los alumnos, tanto individual como socialmente. Objetivos lingüísticos: adquisición de la destreza para comprender y hablar la lengua francesa a nivel elemental, para leer comprensivamente y para escribir frases sencillas sobre un contenido aprendido. Objetivos formativos: acercamiento a una segunda cultura, futuro intercambio técnico o cultural y adquisición de información no disponible a través de la lengua materna para su utilización profesional, investigación, etc.. Un nuevo método de enseñanza del Francés. Se analizan los siguientes aspectos: cómo perfilar el cuadro de estructuras fundamentales del sistema de cada lengua; las diferencias entre la estructura del código hablado y del código escrito; cómo crear situaciones reales para una enseñanza más eficaz del Francés; el paso del oral al escrito; la enseñanza de la fonética; la enseñanza de la civilización francesa; y la evaluación de los objetivos. Se proponen los siguientes tipos de ejercicios estructurales: de repetición (simple, regresiva o con adición), de sustitución (sencilla, y con doble o triple entrada), de transformación (por adición, reducción o transposición), preguntas y respuestas (simples, construidas o abiertas). El proceso de aprendizaje debe seguir las siguientes fases: oir correctamente el francés hablado, comprender lo oido, hablar, entender siempre oralmente, comprensión escrita, expresión escrita. Los medios para crear situaciones reales de aprendizaje son fundamentalmente la imagen (películas fijas, libros con reproducciones de las películas fijas, imágenes creadas en el franelógrafo, películas de cine y vídeos) y la reproducción sonora (cintas magnetofónicas, cassettes y discos). Para la enseñanza del código escrito, se proponen 4 etapas: 1) después de haber memorizado bien la lección, los alumnos dictan y el profesor escribe en el encerado; 2) los alumnos leen las frases escritas por el profesor; 3) los alumnos escriben de nuevo las frases en el encerado, dictándolas el profesor; 4) otros alumnos corrigen las faltas de sus compañeros. Para enseñar la fonética, hay que conseguir que el alumno tome conciencia de la prosodia del Francés: acento, entonación, ritmo, sonidos vocálicos y sonidos consonánticos. La valoración del alumno persigue diferentes fines: orientarle acerca de su aprendizaje, proporcionar al profesor un conocimiento objetivo del alumno y de la clase, facilitar el diagnóstico, motivar a los padres, conocer el nivel alcanzado por los alumnos y ofrecer datos a los niveles superiores para la mejor planificación de la enseñanza. Del campo de la Pedagogía y de la rama didáctica general, se ha desgajado la didáctica de las lenguas extranjeras, como una ciencia en pleno y vigoroso desarrollo.

Número 1 (1995)

Número 1 del Qüern, un butlletí bibliogràfic de literatura i llengua catalanes antigues

Projectes (Enginyeria Industrial) [versió html]

Aquest llibre ha de permetre desenvolupar els criteris que ens permeten d'establir la metodologia de treball que s'ha de seguir en la redacció de Projectes. Tant des del punt de vista d'organització i de gestió, (pràctica i tècnica) i ha de garantir un correcte coneixement de tots i cadascun dels conceptes que intervenen i que permeten d'assolir el producte final: un document redactat pel projectista que recull l'objectiu pel qual ens ha estat encarregat i apte per fer-ne una realitat

Projectes (Enginyeria Industrial) [versió comprimida]

Aquest llibre ha de permetre desenvolupar els criteris que ens permeten d'establir la metodologia de treball que s'ha de seguir en la redacció de Projectes. Tant des del punt de vista d'organització i de gestió, (pràctica i tècnica) i ha de garantir un correcte coneixement de tots i cadascun dels conceptes que intervenen i que permeten d'assolir el producte final: un document redactat pel projectista que recull l'objectiu pel qual ens ha estat encarregat i apte per fer-ne una realitat

Professionals: L'experiència d'un titulat que desenvolupa la seva activitat professional dissenyant circuits electrònics

Seguint amb l’objectiu que titulats a l’Escola Politècnica Superior expliquin detalls de la seva inserció laboral i del seu perfil professional, en aquest segon número de la revista entrevistem el Sr. Albert Pijuan Vila. En aquest cas no es tracta d’un titulat recent, ja que l’Albert va finalitzar els estudis l’any 1988. Recordem que, si bé al 1988 ja disposàvem de d’actual edifici P-I de l’EPS, l’escola encara estava vinculada a la Universitat Politècnica de Catalunya. El principal interès que ens ha mogut a entrevistar l’Albert ha estat el fet de poder presentar les característiques d’un tipus de lloc de treball que pot ser adient per a alguns dels titulats actuals de l’EPS, especialment d’Enginyeria Tècnica Industrial, especialitat Electrònica Industrial i Enginyeria Tècnica en Informàtica de Sistemes. L’entrevista també vol explorar quins són els tipus de coneixements i les competències que haurien d’adquirir els estudiants per adequar-se millor a aquest tipus de sortida professional

Estudiants de la UdG al Festival Internacional de Cinema de Gijón

Breu notícia sobre el Festival Internacional de Cinema de Gijón i presentació de dues pel·lícules de la secció oficial (Welcome i Wakaranai) i dues propostes de la secció retrospectiva (Jean-Gabriel Périot i Harmony Korine)

Multicast extension of unicast charging for QoS Services

In order to successfully deploy multicast services in QoS-aware networks, pricing architectures must take into account the particular characteristics of multicast sessions. With this objective, we propose a charging scheme for QoS multicast services, assuming that the unicast cost of each interconnecting link is determined and that such cost is expressed in terms of quality of service (QoS) parameters. Our scheme allows determining the cost distribution of a multicast session along a cost distribution tree (CDT), and basing such distribution in those pre-existing unicast cost functions. The paper discusses in detail the main characteristics of the problem in a realistic interdomain scenario and how the proposed scheme would contribute to its solution

On the use of QoS requirements as base of multicast charging

We propose a charging scheme for cost distribution along a multicast tree when cost is the responsibility of the receivers. This scheme focuses on QoS considerations and it does not depend on any specific type of service. The scheme has been designed to be used as a bridge between unicast and multicast services, solving the problem of charging multicast services by means of unicast charging and existing QoS routing mechanisms. We also include a numerical comparison and discussions of the case of non-numerical or relative QoS and on the application to some service examples in order to give a better understanding of the proposal

Semi-online neural-Q_leaming for real-time robot learning

Reinforcement learning (RL) is a very suitable technique for robot learning, as it can learn in unknown environments and in real-time computation. The main difficulties in adapting classic RL algorithms to robotic systems are the generalization problem and the correct observation of the Markovian state. This paper attempts to solve the generalization problem by proposing the semi-online neural-Q_learning algorithm (SONQL). The algorithm uses the classic Q_learning technique with two modifications. First, a neural network (NN) approximates the Q_function allowing the use of continuous states and actions. Second, a database of the most representative learning samples accelerates and stabilizes the convergence. The term semi-online is referred to the fact that the algorithm uses the current but also past learning samples. However, the algorithm is able to learn in real-time while the robot is interacting with the environment. The paper shows simulated results with the "mountain-car" benchmark and, also, real results with an underwater robot in a target following behavior

Towards a real-time vision-based navigation system for a small-class UUV

This paper deals with the problem of navigation for an unmanned underwater vehicle (UUV) through image mosaicking. It represents a first step towards a real-time vision-based navigation system for a small-class low-cost UUV. We propose a navigation system composed by: (i) an image mosaicking module which provides velocity estimates; and (ii) an extended Kalman filter based on the hydrodynamic equation of motion, previously identified for this particular UUV. The obtained system is able to estimate the position and velocity of the robot. Moreover, it is able to deal with visual occlusions that usually appear when the sea bottom does not have enough visual features to solve the correspondence problem in a certain area of the trajectory

Mission control system for dam inspection with an AUV

This paper presents a complete control architecture that has been designed to fulfill predefined missions with an autonomous underwater vehicle (AUV). The control architecture has three levels of control: mission level, task level and vehicle level. The novelty of the work resides in the mission level, which is built with a Petri network that defines the sequence of tasks that are executed depending on the unpredictable situations that may occur. The task control system is composed of a set of active behaviours and a coordinator that selects the most appropriate vehicle action at each moment. The paper focuses on the design of the mission controller and its interaction with the task controller. Simulations, inspired on an industrial underwater inspection of a dam grate, show the effectiveness of the control architecture