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  • 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.
21

Prototipação de um torno CNC utilizando realidade virtual. / Prototyping of a lathe CNC using virtual reality.

Antonio Valerio Netto 18 September 1998 (has links)
Este trabalho tem como objetivo o desenvolvimento de um procedimento para a implementação de um protótipo de um torno CNC utilizando realidade virtual. Enfocando principalmente, seu sistema de intertravamento (funcionalidade) e seu modelo geométrico (design físico). Este trabalho se inicia com uma revisão sobre o emprego da realidade virtual em várias áreas inclusive na indústria, e posteriormente discorre sucintamente sobre a estrutura de programação e a justificativa da utilização da ferramenta de construção de ambientes virtuais utilizada no projeto. Em seguida enfoca as especificações do torno CNC virtual e do intertravamento proposto, inclusive com explicações dos passos utilizados para a obtenção da lógica funcional do torno. Adiante é exposto o procedimento adotado para a implementação do protótipo do torno virtual e quais foram os passos utilizados para o desenvolvimento do modelo gráfico incluindo as soluções encontradas para implementação das características deste modelo interativo. Por fim o trabalho apresenta um breve relato sobre a possibilidade do projeto ser empregado nas áreas de prototipação virtual, treinamento e markenting de produtos, e também sugere um roteiro para desenvolvimento de uma máquina-ferramenta utilizando a prototipação virtual. / The aim of this work is the developing of a procedure for the implementation of a CNC lathe prototype using virtual reality, focusing mainly in its interlocking system (functionality) and its geometrical model (physical design). This work starts with a revision about the using of VR in many areas including industry, and afterwards refers briefly on the programming structure and the justificative for the use of the virtual-environment-building tool used in this project. Thereafter it focus the virtual CNC lathing machine’s specifications and the proposed interlocking, with explanations for the steps used in the obtaining of the machine’s functional logic. Later on, are exposed the chosen procedure for the implementation of the virtual machine prototype and which were the steps used for the developing of the graphical model including the found solutions for the implementation of this interactive model. Finally, the work presents a brief report about the possibility of using this project in the virtual prototyping, training and product marketing areas, and also suggests a procedure for the development of a machine tool using virtual prototyping.
22

Formação de estratégias em organizações virtuais / Strategy formation in virtual organizations

Juns, Lúcio Cesar Cury 27 April 2004 (has links)
As organizações virtuais (OVs) se apresentam como uma forma promissora de cooperação entre empresas. Tal forma de organização permite criar um ambiente propício às pequenas e médias empresas que almejam obter acesso a novos mercados e a novas oportunidades de negócios. A função principal das OVs é tornar possível a rápida formação de Empresas Virtuais, que são alianças temporárias entre os componentes de uma OV. O objetivo dessas alianças é explorar oportunidades de negócios específicas, compartilhando habilidades, custos, riscos, infra-estrutura, pesquisa e desenvolvimento. Como toda organização, uma OV necessita formar estratégias que estabeleçam caminhos para atingir seus objetivos organizacionais. No entanto, existe uma carência de métodos e processos de formação de estratégias, adequados à estrutura e às características desse tipo não tradicional de organização. O objetivo deste trabalho é propor um modelo de referência para a formação de estratégias em Organizações Virtuais. Para elaborar o modelo são expostas as várias abordagens relacionadas à formação de estratégias nas organizações tradicionais e determinadas suas adequações à estrutura e às características das OVs. Por fim, o modelo proposto é validado e uma OV real. / The Virtual Organizations (VOs) are presented as a promising way of cooperation between companies. Such a forma of organization allows building a favorable environment to small-medium enterprises that wish to have access to new markets and new business opportunities. The main function of a VO is to make the quick configuration of Virtual Enterprises (VEs), which are temporary alliances between VO partners. The objective of these alliances is to exploit specific opportunities sharing skills, costs, risks, infrastructure, research and development. As all organizations, VOs need to form strategies to establish ways to reach their organizational goals. However, there is a lack of proper methods and processes related to the formation of stategies that adapt to the structure and features of this non-tradicional kind of organization. The goal of this work is to propose a reference model of strategies formation in Virtual Organizations. To elaborate the model, various approaches related to strategy formation in traditional organizations are exposed and established their adequacy to the structure and features of VOs. At last, the model proposed is validated in a real VO.
23

Formação de estratégias em organizações virtuais / Strategy formation in virtual organizations

Lúcio Cesar Cury Juns 27 April 2004 (has links)
As organizações virtuais (OVs) se apresentam como uma forma promissora de cooperação entre empresas. Tal forma de organização permite criar um ambiente propício às pequenas e médias empresas que almejam obter acesso a novos mercados e a novas oportunidades de negócios. A função principal das OVs é tornar possível a rápida formação de Empresas Virtuais, que são alianças temporárias entre os componentes de uma OV. O objetivo dessas alianças é explorar oportunidades de negócios específicas, compartilhando habilidades, custos, riscos, infra-estrutura, pesquisa e desenvolvimento. Como toda organização, uma OV necessita formar estratégias que estabeleçam caminhos para atingir seus objetivos organizacionais. No entanto, existe uma carência de métodos e processos de formação de estratégias, adequados à estrutura e às características desse tipo não tradicional de organização. O objetivo deste trabalho é propor um modelo de referência para a formação de estratégias em Organizações Virtuais. Para elaborar o modelo são expostas as várias abordagens relacionadas à formação de estratégias nas organizações tradicionais e determinadas suas adequações à estrutura e às características das OVs. Por fim, o modelo proposto é validado e uma OV real. / The Virtual Organizations (VOs) are presented as a promising way of cooperation between companies. Such a forma of organization allows building a favorable environment to small-medium enterprises that wish to have access to new markets and new business opportunities. The main function of a VO is to make the quick configuration of Virtual Enterprises (VEs), which are temporary alliances between VO partners. The objective of these alliances is to exploit specific opportunities sharing skills, costs, risks, infrastructure, research and development. As all organizations, VOs need to form strategies to establish ways to reach their organizational goals. However, there is a lack of proper methods and processes related to the formation of stategies that adapt to the structure and features of this non-tradicional kind of organization. The goal of this work is to propose a reference model of strategies formation in Virtual Organizations. To elaborate the model, various approaches related to strategy formation in traditional organizations are exposed and established their adequacy to the structure and features of VOs. At last, the model proposed is validated in a real VO.
24

Implementación de Plataforma Virtual Chamilo para mejorar el rendimiento académico en la I.E. Harvard – Huancayo

Maravi Dominguez, James 17 December 2018 (has links)
Con el presente trabajo se pretende determinar si mediante la utilización de la plataforma de enseñanza virtual Chamilo, mejora el rendimiento académico de alumnos del curso de Ciencias Naturales, segundo grado del nivel secundaria, en el tercer bimestre 2018 en la Institución Educativa. Harvard, Huancayo. Para lo cual se implementó una plataforma de enseñanza virtual Chamilo, diseñando una propuesta de mejora en el desarrollo de la enseñanza aprendizaje a aplicarse al curso de Ciencias Naturales. El diseño de la investigación fue experimental, mediante el promedio de notas de evaluaciones del segundo bimestre (Pre-test) y tercer bimestre (Pos-test), para 1 sección, se tomó una muestra de 30 alumnos. La variable analizada fue la mejora del rendimiento académico mediante el autoaprendizaje. Luego de 6 semanas de prueba, los resultados comparativos entre las notas del 2do y el 3er bimestre, demostró que el uso de la plataforma Chamilo, logró incrementar el puntaje en mayor medida.
25

A framework for immersion in virtual reality

Kanamgotov, Aslan January 2015 (has links)
The purpose of this research is the creation of the framework for immersive Virtual Worlds (VW) development and evaluation of factors affecting user’s immersion experience in 3D virtual worlds. Three experiments have been conducted to evaluate different aspects of the immersion experience in virtual reality. The first experiment aimed to explore the influence of communication on users whilst performing certain activities in a virtual world. The second experiment evaluated how the real-world environment affects users in a virtual world. The third experiment examined the aspect of mobility as a main contributor to a user’s distraction. The fourth experiment partly confirmed previous findings and added new factors, affecting immersion experience. The results of all experiments formed a framework, containing factors which users considered as affecting them during their activities in virtual worlds. During the experimentation phase of this research a combination of qualitative and quantitative methods was used. The Grounded Theory (GT) methodology was applied for data analysis in qualitative part. The major contribution of this research is the framework of factors for building immersive 3D virtual environments. Another contribution is the evaluation of factors affecting users in such an environment.
26

DEVELOPMENT OF AN INTERACTIVE VIRTUAL ENVIRONMENT FOR TRAINING MANUFACTURING OPERATORS

Aoya Sun (9768251) 16 December 2020 (has links)
<div>The use of virtual reality technologies in education and training can provide an opportunity to reduce training costs while increasing the attractiveness and safety for trainees in the manufacturing industry. This thesis strives to show a virtual world which is based upon real world imagery can be embedded in a virtual reality environment and augmented with underlying real world mathematical models to show in real time the consequences of user selected parameters on a running manufacturing process.</div><div>An interactive virtual operator training environment is presented utilizing a VR headset in conjunction with a VR gaming engine which supports the headset and also embeds the behavior details of the underlying manufacturing process.</div><div>To demonstrate this approach an example is developed based on a steel industry roughing mill in which steel slabs are ultimately rolled into coils. This example shows the software application development process given as applied to an interactive training simulator intended for plant operator training which includes the use of the gaming engine Unity 3D, 360-degree video, 3Ds Max and several other software tools.</div><div>The resulting example is a controllable model of the steel plant roughing mill which can be used to enhanced the knowledge of plant operational personnel as to the effects various operating parameters have on the final rolled product while enhancing the understanding of this mill operation for new plant operators.</div>
27

Parities for virtual braids and string links

Gaudreau, Robin January 2016 (has links)
Virtual knot theory is an extension of classical knot theory based on a combinatorial presentation of crossing information. The appropriate extensions of braid groups and string link monoids have also been studied. While some previously known knot invariants can be evaluated for virtual objects, entirely new techniques can also be used, for example, the concept of index of a crossing, and its resulting (Gaussian) parity theory. In general, a parity is a rule which assigns 0 or 1 to each crossing in a knot or link diagram. Recently, they have also been defined for virtual braids. Here, novel parities for knots, braids, and string links are defined, some of their applications are explored, most notably, defining a new subgroup of the virtual braid groups. / Thesis / Master of Science (MSc)
28

Structural optimisation using the principle of virtual work

Walls, Richard Shaun 24 May 2011 (has links)
MSc(Eng),School of Civil and Environmental Engineering, Faculty of Engineering and the Built Environment, University of the Witwatersrand, 2010 / This dissertation presents a new method for the automated optimisation of structures. The method has been developed to: (1) select sections to satisfy strength and deflection requirements using minimum material, and (2) efficiently group members. The member selection method is based on the principle of virtual work, and is called the Virtual Work Optimisation (VWO) method. It addresses multiple deflection and load case constraints simultaneously. The method determines which sections provide the highest deflection and strength resistance per unit mass. When compared to several other methods in the literature, and designs from industry, the VWO method produced savings of up to 15.1%. A parametric investigation of ungrouped, multi-storey frames is conducted using the VWO method to determine optimal mass and stiffness distributions. Unusual mass patterns have been found. Diagonal paths of increased stiffness are formed in the frames, which suggests truss behaviour. A grouping algorithm is presented which determines how efficiently to create a specified number of groups in a structure. The VWO method has been incorporated into the automated algorithm to optimise the grouped structures. Members are grouped according to their mass per unit length. In the algorithm an exhaustive search of all feasible grouping permutations is carried out, and the lightest structure selected. Results produced are up to 5.9% lighter than those obtained using ad hoc grouping configurations found in the literature and based on experience.
29

Virtual factory framework

Borges, Luís Miguel Marques January 2010 (has links)
Estágio realizado na empresa Volkswagem Autoeuropa e orientado pela Eng.ª Margarida Pereira / Tese de mestrado integrado. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 2010
30

Virtual project team performance

Jolly, Richard Paul 08 February 2012 (has links)
The use of Virtual Teams has become substantially more common place as the “global economy” has grown. Technology has enabled teams to collaborate across time and space, but can these teams perform as well or better than their co-located peers? The answer to this question is critical for companies considering offshoring or near shoring specific job functions. This question is also important for companies that require specialized resources that are unavailable in the local market place. The cost of relocating and centralizing specialized resources can be high and can be altogether avoided if virtual team performance is high. This paper addresses the performance question, discusses contingency factors impacting performance, and provides recommendations based both on the research and real world experience of the author / text

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