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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.
31

Multi-User Methods for FEA Pre-Processing

Weerakoon, Prasad 13 June 2012 (has links) (PDF)
Collaboration in engineering product development leads to shorter product development times and better products. In product development, considerable time is spent preparing the CAD model or assembly for Finite Element Analysis (FEA). In general Computer-Aided Applications (CAx) such as FEA deter collaboration because they allow only a single user to check out and make changes to the model at a given time. Though most of these software applications come with some collaborative tools, they are limited to simple tasks such as screen sharing and instant messaging. This thesis discusses methods to convert a current commercial FEA pre-processing program into a multi-user program, where multiple people are allowed to work on a single FEA model simultaneously. This thesis discusses a method for creating a multi-user FEA pre-processor and a robust, stable multi-user FEA program with full functionality has been developed using CUBIT. A generalized method for creating a networking architecture for a multi-user FEA pre-processor is discussed and the chosen client-server architecture is demonstrated. Furthermore, a method for decomposing a model/assembly using geometry identification tags is discussed. A working prototype which consists of workspace management Graphical User Interfaces (GUI) is demonstrated. A method for handling time-consuming tasks in an asynchronous multi-user environment is presented using Central Processing Unit (CPU) time as a time indicator. Due to architectural limitations of CUBIT, this is not demonstrated. Moreover, a method for handling undo sequences in a multi-user environment is discussed. Since commercial FEA pre-processors do not allow mesh related actions to be undone using an undo option, this undo handling method is not demonstrated.
32

The creation of transformative learning cultures in higher education

Messenger, Hazel Susan January 2013 (has links)
This research claims that transformative as opposed to informative learning cultures in higher education are capable of promoting student identity development alongside subject development. It makes a significant pedagogical, conceptual, methodological and contextual contribution to contemporary discussions regarding the nature and purpose of higher education in the 21st century. Transformative learning cultures, based on the pedagogical values of the teachers involved, create an identity workspace where student development is encouraged. This workspace reflects the active demonstration of empathy on the part of the teachers and is represented by an integrated pedagogical pattern consisting of four elements; the development of trust, (ii) the creation of collaborative and supportive communities where students have the opportunities to play different roles, (iii) active confrontation and challenge and (iv) the effective use of pedagogical time and space. A naturalistic, ethnographic methodology and case study approach was used to answer the question ‘what is going on here?’ with teachers of Foundation Degrees in two colleges across several subject disciplines in order to explore the nature and purpose of the learning cultures created. A conceptual framework was developed through the active integration of empirical research and scholarship resulting in a socio- cultural approach to understanding the learning contexts. This was supported by the collection of rich and varied data including photographs, observations and interviews with both teachers and students. Visualisation also supported the interpretation and representation of data in an accessible format. An activity theory approach was adopted to support an integrated analysis of the data, enabling the isolation and identification of the influence of teacher intentions, student dispositions, roles and relationships and how development was influenced by time, space and context.
33

PC software for the teaching of digital signal processing

Katzir, Yoel 03 1900 (has links)
Approved for public release; distribution is unlimited / The Electrical and Computer Engineering Department at the Naval Postgraduate School has a need for additional software to be used in instructing students studying digital signal processing. This software will be used in a PC lab or at home. This thesis provides a set of disks written in APL (A Programming Language) which allows the user to input arbitrary signals from a disk, to perform various signal processing operations, to plot the results, and to save them without the need for complicated programming. The software is in the form of a digital signal processing toolkit. The user can select functions which can operate on the signals and interactively apply them in any order. The user can also easily develop new functions and include them in the toolkit. The thesis includes brief discussions about the library workspaces, a user manual, function listings with examples of their use, and an application paper. The software is modular and can be expanded by adding additional sets of functions. / http://archive.org/details/pcsoftwarefortea00katz / Major, Israeli Air Force
34

Um estudo sobre o espaço de trabalho informativo e o acompanhamento em equipes ágeis de desenvolvimento de software / An study on informative workspaces and tracking in agile development teams

Oliveira, Renan de Melo 24 January 2012 (has links)
Podemos encontrar em métodos ágeis como no Extreme Programming [Beck, 1999, Beck e Andres, 2006], no Scrum [Schwaber, 2008], no Crystal Clear [Cockburn, 2005], e no Lean Software Development [Poppendieck e Poppendieck, 2007] referências relacionadas à manipulação e disponibilização de métricas e outras informações no ambiente de desenvolvimento. Neste trabalho, estas atividades são consideradas como tarefas de acompanhamento ágil. Observamos em métodos ágeis a importância de se realizar ações (práticas) baseadas em alguns princípios como guidelines [Poppendieck e Poppendieck, 2007]. Por isto, realizamos uma análise bibliográca na literatura disponível para compreender princípios ágeis que possam afetar na execução deste tipo de tarefa, além de escrever sobre métricas no contexto de métodos ágeis e engenharia de software. Apesar da bibliograa, não encontramos pesquisas experimentais com o objetivo de levantar e (ou) compreender aspectos relacionados ao sucesso na aplicação deste tipo de tarefa em ambientes de desenvolvimento. Para isto, realizamos neste trabalho uma pesquisa experimental com este objetivo, utilizando uma abordagem de métodos mistos sequenciais de pesquisa [Creswell, 2009]. Escolhemos aplicar esta pesquisa em um conjunto de quinze equipes de desenvolvimento ágil, reunidas em realizações da disciplina Laboratório de Programação Extrema do IME-USP nos anos de 2010 e 2011. Esta pesquisa foi realizada em quatro fases sequenciais. Na primeira fase, realizamos sugestões para as equipes de desenvolvimento vinculadas ao acompanhamento ágil a m de levantar aspectos valiosos em sua aplicação utilizando uma abordagem baseada em pesquisa-ação [Thiollent, 2004]. Baseado nestes resultados, agrupamos alguns destes aspectos como heurísticas para o acompanhamento ágil, modelo similar ao de Hartmann e Dymond [2006]. Na segunda fase, aplicamos um questionário para vericar a validade das heurísticas levantadas. Na terceira fase, realizamos entrevistas semi-estruturadas com alguns integrantes destas equipes para compreender o por quê da validade das heurísticas levantadas, sendo analisadas com técnicas de teoria fundamentada em dados (grounded theory)[Strauss e Corbin, 2008]. Na quarta fase, reaplicamos o questionário da fase 2 em outro ambiente para triangulação da validade das heurísticas. Como resultado nal da pesquisa, estabelecemos um conjunto de heurísticas para o acompanhamento ágil, além de avaliações quantitativas de seus aspectos em dois ambientes, juntamente a diversas considerações qualitativas sobre sua utilização. Realizamos um mapeamento tanto das heurísticas como de seus conceitos relacionados à literatura disponível, identicando aspectos já existentes porém expandidos pela realização da pesquisa, e aspectos ainda não discutidos que podem ser considerados como novos na área. / It is possible to find on the agile methods several references related to managing and displaying relevant information in a software development worplace. These references are available in agile methods such as Extreme Programming [Beck, 1999, Beck e Andres, 2006], Scrum [Schwaber, 2008], Crystal Clear [Cockburn, 2005], Lean Software Development [Poppendieck e Poppendieck, 2007],etc. In our work, we name this kind of activity as agile tracking, relating it to the tracker role defined by Beck [1999]. We noticed the importance of performing actions (practices) based on a set of principles as guidelines [Poppendieck e Poppendieck, 2007], which is deeply associated with agile methods. Taking this matter into account, we performed a literature review in order to discuss a few agile principles that could affect the execution of agile tracking related tasks. We also describe a few works directly related to metrics, both on the agile methods and on the software engineering area in general. Even with related references in the literature, we could not find empirical researches with the goal of raising/understanding aspects related to successfully performing this kind of task on agile environments, which could be helpful on managing informations and informative workspaces. In order to accomplish this goal, we performed a research using a sequential mixed research methods approach [Creswell, 2009]. We chose to apply our research on a set of fifteen agile teams gathered on the IME-USP\'s \"Laboratory of Extreme Programming\" course in 2010 and 2011. This research was performed in four sequential phases. In the first phase, we made several suggestions to the agile teams, regarding agile tracking, using and approach based on action research [Thiollent, 2004]. We used this initial approach in order to gather relevant aspects of their use of agile tracking. Based on these results, we clustered some aspects as \"heuristics for agile tracking\", the same model used by Hartmann e Dymond [2006]. In phase two, we applied a survey to evaluate the validity of the proposed heuristics. In phase three, we gathered data from a few semi-structured interviews performed on team members in order to understand the reasons behind the proposed heuristics, in which we used grounded theory [Strauss e Corbin, 2008] coding techniques for analysis. In phase four, we reapplied phase two survey on a different environment in order to triangulate the heuristics evaluation data gathered on phase 2. As the result of this empirical research, a set of heuristics were established with quantitative evaluation data and several related qualitative concepts. We also relate the set of heuristics and associated concepts with other works in agile methods, highlighting aspects expanded by this research and some others that we could not directly find in the literature, which could be considered as new in the area.
35

Avaliação do comportamento cinemático de um mecanismo paralelo tridimensional. / Evaluation of kinematic performance of a tridimensional parallel mechanism.

Malvezzi, Fernando 14 June 2006 (has links)
Este trabalho propõe uma nova estrutura cinemática paralela tridimensional com três graus de mobilidade que pode ser aplicada como robô manipulador. O volume do espaço de trabalho disponível é empregado como índice para avaliar o desempenho cinemático do mecanismo. As cinemáticas de posição e velocidade são desenvolvidas, tendo em vista o levantamento das configurações singulares e do espaço de trabalho. Os resultados obtidos com as cinemáticas direta e inversa são comparados de modo a verificar a correspondência entre eles. São levantadas diversas configurações singulares que correspondem ao alinhamento entre as barras das cadeias ativas do mecanismo e uma família de singularidades para uma das cadeias ativas é apresentada. O volume do espaço de trabalho do mecanismo é calculado pelo método da discretização, de modo a avaliar o volume do espaço de trabalho disponível, bem como a identificação da influência dos parâmetros dimensionais do mecanismo sobre este volume. O volume do espaço de trabalho com os parâmetros ótimos é expressivo, quando comparado com aqueles alcançados por manipuladores robóticos convencionais. / This dissertation proposes a novel three-degree-of-freedom parallel kinematic structure in order to be applied as a three-dimensional robot manipulator. The volume of the available workspace is employed as a performance index to evaluate the kinematic behavior of the mechanism. The position and velocity kinematics are developed for mapping singular configurations and evaluating the workspace. The results obtained by performing the direct and inverse kinematics are compared in order to verify the consistency between them. It is demonstrated that most of singular configurations is represented by the alignment of the links that belong to each active chain. In addition, a family of singularities for one of the active chains is presented. The volume of the workspace is calculated by using the discretization method not only for evaluating the feasible workspace but also for identifying the influence of dimensional parameters with respect to this volume. The achieved workspace by employing the optimal parameters is comparable to that reached by conventional robot manipulators.
36

Constrained Motion Planning System for MRI-Guided, Needle-Based, Robotic Interventions

Bove, Christopher 25 April 2018 (has links)
In needle-based surgical interventions, accurate alignment and insertion of the tool is paramount for providing proper treatment at a target site while minimizing healthy tissue damage. While manually-aligned interventions are well-established, robotics platforms promise to reduce procedure time, increase precision, and improve patient comfort and survival rates. Conducting interventions in an MRI scanner can provide real-time, closed-loop feedback for a robotics platform, improving its accuracy, yet the tight environment potentially impairs motion, and perceiving this limitation when planning a procedure can be challenging. This project developed a surgical workflow and software system for evaluating the workspace and planning the motions of a robotics platform within the confines of an MRI scanner. 3D Slicer, a medical imaging visualization and processing platform, provided a familiar and intuitive interface for operators to quickly plan procedures with the robotics platform over OpenIGTLink. Robotics tools such as ROS and MoveIt! were utilized to analyze the workspace of the robot within the patient and formulate the motion planning solution for positioning of the robot during surgical procedures. For this study, a 7 DOF robot arm designed for ultrasonic ablation of brain tumors was the targeted platform. The realized system successfully yielded prototype capabilities on the neurobot for conducting workspace analysis and motion planning, integrated systems using OpenIGTLink, provided an opportunity to evaluate current software packages, and informed future work towards production-grade medical software for MRI-guided, needle-based robotic interventions.
37

The Relationship Between Workspace and Office Placement and Workforce Productivity and Wellbeing

Cvijanovic, Mladen 01 January 2019 (has links)
The quality of the physical workspace environment has been widely debated in research and corporate communities. Inadequate workspace conditions have been associated with elevated levels of work-related stress, productivity, and job satisfaction. However, scholarly literature offers very little on the relationship between workspace and office placement, and workforce productivity and wellbeing. The purpose of this non-experimental quantitative study was to examine the impact of customized workspace and strategic office placement on work related stress, productivity, and job satisfaction. Optimal distinctiveness theory and cognitive-motivational-relational theory provided the theoretical framework for this study. Nine research questions in this study were designed to identify any statistically significant difference in any of the three dependent variables(work-related stress, productivity, job satisfaction) in relation to workspace design and office placement. The Work Stress Scale, Individual Work Performance Questionnaire, and the Brief Index of Affective Job Satisfaction served as data collection instruments. Data were collected from a convenience sample of 131 male and female full-time employees from 5 different organizations nationwide. With a 2x2 causal-comparative research design, a multivariate analysis of variance was conducted, which showed statistically significant difference on work-related stress and job satisfaction in relation to workspace design with no statistically significant difference for the remaining seven research questions. This study offers significant insight into best practices for ensuring the highest quality of workspace environment to enable optimal employee performance along with improved overall wellbeing.
38

Express Location : Supporting Coordination of Mobile Delivery Work

Westerlund, Markus, Normark, Maria, Holmquist, Lars Erik January 2011 (has links)
This paper introduces Express Location, a mobile web application, supporting drivers in delivery service in the daily coordination of work. Remote communication and cooperation takes place on a shared map view around the drivers’ locations and next stop, through a drawing/doodling tool and multiple visual object representations. The aim is to understand the working situation and the use of locations in the daily work to better support the coordination of mobile delivery work. / <p>© (2011) ACM. This is the author’s version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version was published in <em>CSCW '11 Proceedings of the ACM 2011 conference on Computer supported cooperative work</em> http://doi.acm.org/10.1145/1958824.1958956</p>
39

Mixed-fidelity prototyping of user interfaces

Petrie, Jennifer 08 February 2006
<p> This research presents a new technique for user interface prototyping, called mixed-fidelity prototyping. Mixed-fidelity prototyping combines low-, medium-, and high-fidelity interface elements within a single prototype in a lightweight manner, supporting independent refinement of individual elements. The approach allows designers to investigate alternate designs, including more innovative designs, and elicit feedback from stakeholders without having to commit too early in the process. As well, the approach encourages collaboration among a diverse group of stakeholders throughout the design process. For example, individuals who specialize in specific fidelities, such as high-fidelity components, are able to become involved earlier on in the process. </p> <p> We developed a conceptual model called the Region Model and implemented a proof-of-concept system called ProtoMixer. We demonstrated the mixed-fidelity approach by using ProtoMixer to design an example application. </p> <p> ProtoMixer has several benefits over other existing prototyping tools. With ProtoMixer, prototypes can be composed of multiple fidelities, and elements are easily refined and transitioned between different fidelities. Individual elements can be tied into data and functionality, and can be executed inside prototypes. As well, traditional informal practices such as sketching and storyboarding are supported. Furthermore, ProtoMixer is designed for collaborative use on a high-resolution, large display workspace. </p>
40

Dynamics and Motion of a Six Degree of Freedom Robot Manipulator

2012 December 1900 (has links)
In this thesis, a strategy to accomplish pick-and-place operations using a six degree-of-freedom (DOF) robotic arm attached to a wheeled mobile robot is presented. This research work is part of a bigger project in developing a robotic-assisted nursing to be used in medical settings. The significance of this project relies on the increasing demand for elderly and disabled skilled care assistance which nowadays has become insufficient. Strong efforts have been made to incorporate technology to fulfill these needs. Several methods were implemented to make a 6-DOF manipulator capable of performing pick-and-place operations. Some of these methods were used to achieve specific tasks such as: solving the inverse kinematics problem, or planning a collision-free path. Other methods, such as forward kinematics description, workspace evaluation, and dexterity analysis, were used to describe the manipulator and its capabilities. The manipulator was accurately described by obtaining the link transformation matrices from each joint using the Denavit-Hartenberg (DH) notations. An Iterative Inverse Kinematics method (IIK) was used to find multiple configurations for the manipulator along a given path. The IIK method was based on the specific geometric characteristic of the manipulator, in which several joints share a common plane. To find admissible solutions along the path, the workspace of the manipulator was considered. Algebraic formulations to obtain the specific workspace of the 6-DOF manipulator on the Cartesian coordinate space were derived from the singular configurations of the manipulator. Local dexterity analysis was also required to identify possible orientations of the end-effector for specific Cartesian coordinate positions. The closed-form expressions for the range of such orientations were derived by adapting an existing dexterity method. Two methods were implemented to plan the free-collision path needed to move an object from one place to another without colliding with an obstacle. Via-points were added to avoid the robot mobile platform and the zones in which the manipulator presented motion difficulties. Finally, the segments located between initial, final, and via-points positions, were connected using straight lines forming a global path. To form the collision-free path, the straight-line were modified to avoid the obstacles that intersected the path. The effectiveness of the proposed analysis was verified by comparing simulation and experimental results. Three predefined paths were used to evaluate the IIK method. Ten different scenarios with different number and pattern of obstacles were used to verify the efficiency of the entire path planning algorithm. Overall results confirmed the efficiency of the implemented methods for performing pick-and-place operations with a 6-DOF manipulator.

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