• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1894
  • 12
  • Tagged with
  • 1906
  • 1906
  • 661
  • 646
  • 250
  • 119
  • 114
  • 94
  • 86
  • 69
  • 66
  • 64
  • 63
  • 53
  • 52
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Organização de um centro de processamento de dados: âmbito EESC-USP not available

José Savério Lia 3 February 1977 (has links)
Este trabalho tem suas origens e baseia-se na experiência que a direção dos negócios de um Centro de Processamento de Dados, no âmbito Universitário, através da Escola de Engenharia de São Carlos, da Universidade de são Paulo, tem ensejado ao autor, durante diversos anos. O caráter das questões abordadas situa-se quase sempre no plano geral. Isto significa que não há a preocupação do estudo de especificidades, não obstante, por muitas vezes, relevantes méritos possam estar associados a estudos de problemas dessa natureza. Mantém-se, consequentemente, a atenção voltada para linhas de ação genéricas e duas legislações, constante de delineamentos básicos para a entidade, assumem importante papel. A primeira, sob a égide da qual surgiu o Centro de Processamento de Dados, representa, ainda nos dias atuais, o documento que oficialmente formaliza a existência do Centro. A segunda traduz a evolução havida entre uma e outra. De permeio e \"a posteriori\", portanto, desenvolve-se este estudo, cuja maior fonte de subsídios é propiciada pelos acontecimentos do dia-a-dia, sintetizados e analisados, sob o enfoque geral já observado. Um comentário é dedicado ao conjunto Centro de Processamento de Dados - Departamento correspondente. São apresentadas algumas comparações entre a atividade de um C.P.D. e aquelas relativas a outros organismos universitários, no intuito de obter-se melhor visualização ou compreensão da função do Centro de Processamento no ambiente considerado - a Universidade. This work has its origins and is based on the experience of the author who has been directing the Processing Data Center of the Engineering School of São Carlos, University of São Paulo, for many years. Therefore it refers mainly the organization and activities of the institution. It considers many aspects of the daily labor in the Center, its relationship and its organizational model by comparison with other universitary organisms in order to visualize and to permit the understanding of its functions, and looks for the aims of the Center in a universitary environment. It considers too its rules and formal structure after having examined some legislations. The extension of its services to the community and some informational aspects such as historical or operational including those referring to the general lines observed in the construction of the building are also mentioned.
2

Propriedades Eletro-Ópticas do Ion Ag+ fora de centro em RbI Not available

Dario Antonio Donatti 10 March 1982 (has links)
O defeito substitucional Ag+, foi investigado em RbI, CsI e CsBr, utilizando técnicas de ITC e eletro-ópticas. Para o RbI: Ag+, utilizando uma técnica de difusão, foi possível obter amostras homogêneas com concentrações controladas. O espectro de absorção óptica do defeito isolado para uma amostra \'quenched\', consiste de 4 bandas UV em 4.82, 4.93, 5.12 e 5.47 eV. Medidas eletro-ópticas, usando técnicas dc, mostraram que o alinhamento dipolar somente é possível acima de 22K. Todas as bandas UV mostraram pequenas mudanças no momento de ordem zero, para campos elétricos aplicados ao longo das direções e (tipica¬mente, Δ K/K ~ 5.10-2 para E ~ 1,3.105V/cm). Com sensibilidade experimental (Δ K/K ~ 5.10-4), não foi observado variação na direção . Os resultados mostram sem dúvida que o íon Prata em RbI, está em posição fora de centro. Medidas de ITC com pressão uniaxial indicaram que o dipolo elástico Ag+ tem uma forma elipsoidal alongada. Dentro dos erros experimentais, os resultados eletro-ópticos indicam que o dipolo está orientado na direção ou na direção com movimento restrito à 90° no plano . Uma definitiva predominância do modelo mais provável ainda não foi obtida. Para o modelo e assumindo que as bandas centradas em 4.82 e 5.12 eV são completamente polarizadas perpendicularmente ao eixo do dipolo, (polarização ?), todos os resultados dão um valor médio para o momento de dipolo como sendo p = 1.16 ± 0.05 eÅ. Para o modelo com movimento restrito, os resultados são bem ajustados usando o valor do momento de dipolo como sendo p = 0.95 ± 0.05 eÅ, e assumindo que as bandas centradas em 4.82 e 5.12 eV tem somente transições elétricas π ao longo da direção . Por outro lado, se essas bandas tem transições elétricas ? iguais ao longo das direções e , o valor do momento de dipolo e p = 1.34 ± 0.05 eÅ. Resultados preliminares mostraram que o processo de relaxação para T < 25K, apresenta um comportamento similar ao encontrado para a reorientação a 90° em RbCl: Ag+ e RbBr: Ag+. Para altas temperaturas, a lei de Arrhenius é obedecida com uma energia de ativação de 62 meV, mostrando um bom acordo entre as técnicas de ITC e eletro-ópticas. O resultado da força do oscilador indica um potencial fora de centro em RbI: Ag+ e em CsBr: Ag+. Medidas de ITC em CsBr: Ag+ e em CsI: Ag+ , não apresentaram pico de corrente de polarização na região entre 12K e 300K. Substitutional Ag+ defects have been investigated in RbI, CsI and CsBr by ITC and electro-optical techniques. For RbI: Ag+ homogeneous and controlled concentration have been achived using a diffusion technique. After quenching and rapid cooling the absorption spectrum of isolated defects consists of 4 UV bands at 4.82, 4.93, 5.12 and 5.47 eV. Electro-optical aligment using a de technique shows that the aligment is only possible down to 22K. Weak zero moment changes have been found for all UV bands for an applied field along the and directions only (tipically Δ K/K ~ 5.10-2 for E ~ 1,3.105V/cm). Within the experimental sensibility (ΔK/K ~ 5.10-4), no variation has been observed along . The results show without ambiguity that silver ions in RbI are in an off-center position. Measurements of ITC under uniaxial pressure indicate that the Ag+ elastic dipole has an elongated ellipsoidal form. Within experimental errors the electro-optical results indicate that the Ag+electric dipole stays either along direction or along direction but with restricted 90° motion in a plane. A definite ruled out of one of the model is not yet possible. For the model and assuming that the main absorption bands at 4.82 and 5.12 eV are polarized perpendicular to the dipole axis (π po1arization ), all the results give a mean value for the dipole moment p = 1.16± 0.05 eÅ For the model with restrictive motion, the results can be fitted as well using a value p = 0.95 ± 0.05 eÅ, assuming that the main bands at 4.82 and 5.12 eV have only a ? electric transition along the direction. On the other hand if these bands have equal ? electric transitions along the and direction the dipole moment value is p = 1.34 ± 0.05 eÅ. Preliminary results of the kinetics of the reorientation process show for TញK a behavior similar to the one found for 90° reorientation in RbCl: Ag+ and RbBr: Ag+. The high temperature behavior follows an Arrhenius law with an activation energy of 62 meV, in good agreement with the ITC measurements. The results of the oscillator strength also confirm an off-center potential in RbI: Ag+, as well as in CsBr: Ag+. ITC measurements in CsBr: Ag+ and CsI: Ag+, do not show a peak of the depolarization current
3

Arquiteturas para fonte de muito alta tensão em instrumentação: estudo comparativo e projeto otimizado para o caso de um osciloscópio not available

Baker Jefferson Mass 2 September 1985 (has links)
A ideia central deste trabalho consiste na síntese de um sistema eletrônico destinado a gerar uma tensão contínua e estável de 2000 V para acelerar elétrons no tubo de raios catódicos de um osciloscópio. Todas as concepções alternativas são examinadas e avaliadas, sendo estabelecida a forma ótima ou quase ótima, que compreende um oscilador harmônico transistorizado alimentado por uma tensão contínua de nível baixo e cuja saída senoidal tem sua amplitude elevada através de um multiplicador de tensão Cockroft-Walton. De modo a obter alta regulação da tensão de saída o circuito e provido de realimentação degenerativa, com o sinal de erro agindo sobre o elemento ativo do oscilador. O componente ativo empregado e um transistor de efeito de campo de porta isolada, de geometria vertical (VHOS). Para se estabelecer uma relação entre a amplitude das oscilações, a tensão final de saída e a variável de controle no elemento ativo, uma análise detalhada é levada a efeito; uma vez que o oscilador intrinsicamente não linear, constituindo um caso particular do problema clássico de Van der Pol. Além disso, o transistor empregado é de concepção recente e suas características diferem das de um transistor convencional. A estabilidade do sistema é estudada e o desempenho de um protótipo é apreciado através de medidas efetuadas. The central idea of this work is the synthesis of an electronic system for generating a continuous and stable voltage of 2000 V to accelerate electrons in the cathode-ray tube of an oscilloscope. All alternative concepts are examined and evaluated, the optimum or quasi optimum form being thus established. That comprises an harmonic transistor oscillator powered by a low level continuous voltage, the sinusoidal output of which has its amplitude upward shifted-through a Cockroft-Walton voltage multiplier. In order to obtain high output voltage regulation the circuit is provided with degenerative feedback, with the error signal acting upon the active element of the oscillater. The active component employed is a power insulated gate field-effect-transistor of vertical geometry (VMOS). To establish a relation between the amplitude of the oscillations, the final output voltage and the control variable in the active element, a detailed analysis is carried out since the oscillator is intrinsically nonlinear constituting a particular case of the classical Van der Pol problem. Furthermore the transistor employed is of recent concept, its characteristics differing from those of a conventional one. The system stability is studied and the performance of a prototype is appreciated through measurements performed.
4

Implantação do reúso de componentes no processo de desenvolvimento de software Not available

Talita Andréa Avante Rozante 19 March 2003 (has links)
Frente à grande demanda por software e à forte competitividade existente no mercado atual, o alcance de alguns objetivos, tais como aumento de qualidade e de produtividade, redução dos prazos de entrega e dos custos globais do desenvolvimento de software, tem sido apresentado como bastante importante para o sucesso de uma organização de desenvolvimento de sistemas. Neste cenário, o reúso sistemático de componentes de software tem exercido o papel de grande colaborador para o alcance desses objetivos. Para a concretização de sua prática efetiva. porém, o reúso vêm enfrentando barreiras de diversas origens, como questões técnicas e organizacionais. Assim, é importante que a introdução do reúso aborde tais questões de maneira integrada e gradativa, respeitando o tempo natural da organização para a absorção de mudanças e cuidando para que seu impacto seja reduzido. Desta maneira, o principal objetivo deste projeto foi o desenvolvimento de uma estratégia que sistematizasse o processo de introdução do reúso em uma organização, considerando mudanças organizacionais, técnicas e processuais, assim como sua sequência de execução, suas consequências e dificuldades. Para criar e validar esta estratégia, foi desenvolvido um estudo de caso no Laboratório de Inteligência Computacional do Instituto de Ciências Matemáticas e de Computação da Universidade de São Paulo. Neste estudo de caso, foi também selecionado um conjunto mínimo de atividades e requisitos importantes para viabilização do reúso e desenvolvida a especificação de um ambiente, denominado RaCooMN [Reusable Components Management ENvironment), que automatiza muitas das atividades propostas na estratégia referentes ao armazenamento e gerenciamento dos componentes. It is very important for thc success of a software development organization to achieve objetives sueh as the productivity and the quality raise, delivery time and software development global costs reduced. In this context, the systematic reuse of software components has assumed the role of an important collaborator in order to reach these objectives. In order to become a concrete practice, however, the reuse faces several barriers regarding technical and organizational issues. Thus, it is important that, when introducing reuse in an organization, we considcr these issues in an integrated and gradual manner, observing the time for the organization to absorb changes and also trying to reduce its impact. The main objective of this project was to develop a strategy to systematize the introduction of the reuse in an organization, considering organizational, technical and processual changes, as well as thcir execution scquence, consequences and difíiculties. In order to crcate and validatc this strategy, we developed a case study at a computing laboratoiy in the ICMC. Additionally, it was selected a minimum set of activities and requirements to make reuse possible. Moreover, it was developed an environment specification, named RaCooMN (Reusable Components Management ENvironment), aimed at automatize some strategy activities regarding component storagc and management.
5

Zeros Elementares de Álgebras de Lie de Campos de Vetores Not available

Luiz Carlos Martins Junior 18 September 1996 (has links)
Quando um grupo de Lie nilpotente age sem pontos fixos sobre uma superfície compacta M, a característica de Euler X(M) de M é zero [11]. Isso sugere a possibilidade de um teorema tipo Poincaré-Hopf para ações destes grupos em variedades compactas. J.F.Plante em seu artigo \"Elementary Zeros of Lie Algebras of Vector Fields\" , [12], obtém urna caracterização dos zeros elementares dessas álgebras em dois casos: quando g é nilpotente e quando g é semi-simples. Ele também mostra que para uma álgebra de Lie abeliana g de campos de vetores de uma superfície compacta, tal que todo zero de g é elementar, existe um subconjunto S ⊂ g tal que g — S tem medida nula e para todo X ∈ S valem: (a) O conjunto de zeros isolados de X coincide com o conjunto (finito) de zeros de g; (b) Se p1,..., pk são os zeros de g então ∑k1=1 índice (X, pi ) = x (M) . Baseado neste teorema e em um exemplo, ele mostra que não é possivel definir o índice de g em um zero isolado p como o índice de um zero de um elemento genérico X ∈ S em p. Embora ele não diga, o leitor fica com a impressão que um teorema do tipo Poincaré-Hopf, como mencionado no começo, não parece existir. Nesta dissertação faço uma exposição detalhada do artigo de J.F.Plante ilustrando com exemplos os teoremas do artigo. When a nilpotent Lie group acts without fixed points on a compact swface M, the Euler characteristic X(M) of (M) of M vanishes [11]. This suggests the possibility of a Poincaré-Hopf type theorem for actions of these groups on compact manifolds. J.F.Plante in his paper \" Elementary Zeros of Lie Algebras of Vector Field,s\" , [12] charactenze the elementary zeros of these algebras in two cases: when g is nilpotent and when g is semi-simple. He also shows that for a abelian Lie aþbra g of vector fields of a compact surface such that every zero of g is elementary, there exists a set S ⊂ g such that g — S has measure zero and for X ∈ S: (a) The set of isolated zeros of X coincides with the (finite) zero set of g; (b) If p1,...,pk are the zeros of g then ∑ki=1, index (X, pi) : X(M) . Based on this last theorem and one example, he shows that it is not possible to define the index of g at an isolated zeto p as the index of a generic element X ∈ S at p. Although he does not say it, the readers get the impression that a Poincaré-Hopf type theorem, as mentioned at the beginning, does not exist. Ln this dissertation I detail Plante\' paper illustrating it with several examples.
6

Teaching about frogs in Grade 7: a case study on integrating indigenous knowledge into the science curriculum.

Minter, Jean Elizabeth 2005 (has links)
Constructivism and worldview theory were translated into the design of a series of science lessons for Grade 7 learners. Indigenous knowledge about frogs, elicited from the local community, was incorporated into the lessons together with frog myths from other cultures, in order to introduce the curricular topics of conservation and biodiversity. The lessons then focussed on pollution of our natural environments and the loss of biodiversity as evidenced by declining frog populations. The lessons were implemented by the researcher and the participants’ activities were assessed using rubrics. Participants’ attitudes towards frogs were assessed using pre- and post-test questionnaires. Qualitative analysis of the data revealed that experiences and learning had taken place amongst the participants, and had resulted in a more positive attitude towards frogs. Participants had also developed a better understanding and appreciation of biodiversity and the need for its conservation. Lessons learnt from the research were that information on indigenous knowledge about frogs was not available in the literature and that no guidance was given to teachers regarding the incorporation of indigenous knowledge into the South African Science curriculum, and that some aspects of the assessment had been subjective and needed to be improved. Nevertheless, the researcher has shown that by introducing indigenous knowledge in a series of science lessons, using constructivist principles, and acknowledging the existence of differing worldviews, it is possible to expose learners to positive and effective learning experiences that foster the development of an appreciation of the importance of conservation and the need to maintain biodiversity. Thesis (M.Sc.) (Education) --University of Limpopo, 2005. Not listed
7

An investigation of the effects of police suicide on the well-being of the South African Police Service members in Polokwane,an area in Limpopo Province.

Mokgobu, Tebogo Suzan 12 May 2010 (has links)
The study is entitled “the effects of police suicide on the well-being of the South African Police Service members in Limpopo”. The study focuses on suicide among members of the South African Police, as this is a serious problem. Police officers are more likely to commit suicide more than members of the general population. The high stressful nature of police work has been cited by police officers to be the primary contributing factor. Suicide among the police officers has a negative impact on their colleagues. They suffer set-backs and as such it affects both their work productivity and morale. This study is comprised of four chapters. Chapter 1 This chapter is mainly an introduction to the study. The chapter includes the problem statement, motivation for the study, aims and objectives and the importance of the study. The chapter also outlines the methodology of the study, the definition of key concepts used in the study and the limitations of the study. Chapter 2 Chapter 2 comprises the literature background for the study. The literature focuses largely on the causes of suicide, aspects that influences suicide, and suicide prevention programmes. The literature reflects on how suicide survivors react to police suicide and also on the services of counseling offered by South African Police. This chapter further discusses the police organizational culture and South African Police Services (SAPS) framework V Chapter 3 Chapter 3 focuses on data analysis and interpretation of the findings of the study. The analysis focuses on the respondents’ personal background and how suicide affect colleagues, families and society at large as recorded during interviews. Chapter 4 Chapter 4 concludes the study by discussing and presenting a summary of the findings of the study and the implications thereof. A conclusive report is made and recommendations for reducing the high rate of suicide in SAPS and for further research are made. Thesis (M.Dev) --University of Limpopo,2006. Not listed
8

The practice of supply chain management in Capricorn District with particular reference to Aganang Municipality

Rabodiba, Malola Japhta 28 May 2010 (has links)
The study investigated the supply-chain management practices in Capricorn District Municipality and Aganang Local Municipality. The study also looked at the implementation of the supply-chain management policies in the Capricorn District and Aganang Local municipalities. The study critically analysed the practice of supply-chain management in Capricorn and Aganang municipalities and the challenges faced by these municipalities in terms of procurement and supply-chain management in general. The findings of the study will assist government with interventions that are necessary for the improvement of the supply-chain management practices in the local sphere of government. The study also investigated and analysed possible non-compliance with supply-chain management legislation and policies, and purchasing and tender irregularities in Capricorn District and Aganang Local municipalities. It also investigated whether the evaluation and adjudication of bids were in accordance with the applicable legislation. The study further recommended possible strategies and mechanisms to improve procurement and supply-chain management to prevent fraud and corruption. Thesis (MPA) --University of Limpopo, 2006. Not listed
9

Exploring the integration of indigenous beliefs in the teaching and learning of school sciences: a case study on lightning

Pabale, Morongwa Fonthy 28 May 2010 (has links)
This research study was carried out to explore the integration of Indigenous Knowledge Systems with a science topic, as advocated by the South African policy document called the National Curriculum Statement. The focus was on the integration of Indigenous Beliefs about lightning with the teaching of Static Electricity. The sample consisted of all my grade 10 learners who are eleven in number and one elder per learner, thus a sample of 22 people was made use of. The research process took place in two phases: the Baseline Study and the Teaching and Learning Process. The intention was to use data collected in the first phase to design the teaching and learning activities in the second phase. A series of four lessons was designed, and a variety of qualitative methods were used to collect data: interviews, questionnaires, and constructivist techniques. The findings presented in this research study are based on an analysis of four videotaped lessons and learners’ responses from the worksheets and evaluation forms. These findings suggest that for maximum results, the integration of Indigenous Knowledge Systems should be an ongoing process. Thesis (MSc Ed) --University of Limpopo, 2006. National Research Foundation (NRF)
10

Teaching about frogs in Grade 7: a case study on integrating indigenous knowledge into the science curriculum.

Minter, Jean Elizabeth 2005 (has links)
Thesis (M.Sc.) (Education) --University of Limpopo, 2005. Constructivism and worldview theory were translated into the design of a series of science lessons for Grade 7 learners. Indigenous knowledge about frogs, elicited from the local community, was incorporated into the lessons together with frog myths from other cultures, in order to introduce the curricular topics of conservation and biodiversity. The lessons then focussed on pollution of our natural environments and the loss of biodiversity as evidenced by declining frog populations. The lessons were implemented by the researcher and the participants’ activities were assessed using rubrics. Participants’ attitudes towards frogs were assessed using pre- and post-test questionnaires. Qualitative analysis of the data revealed that experiences and learning had taken place amongst the participants, and had resulted in a more positive attitude towards frogs. Participants had also developed a better understanding and appreciation of biodiversity and the need for its conservation. Lessons learnt from the research were that information on indigenous knowledge about frogs was not available in the literature and that no guidance was given to teachers regarding the incorporation of indigenous knowledge into the South African Science curriculum, and that some aspects of the assessment had been subjective and needed to be improved. Nevertheless, the researcher has shown that by introducing indigenous knowledge in a series of science lessons, using constructivist principles, and acknowledging the existence of differing worldviews, it is possible to expose learners to positive and effective learning experiences that foster the development of an appreciation of the importance of conservation and the need to maintain biodiversity. Not listed

Page generated in 0.0731 seconds