Tool wear is a significant problem for manufacturing companies and represents a major challenge in their operations, but it is also a way they can gain a competitive advantage. To do this it is important to set up a standard procedure to develop high performing tooling. This thesis outlines how the Finite Element (FE) method can be used to understand and develop tool geometry. FE based simulation, as a numerical method, is a reliable method to assess the performance of a cutting tool before conducting machining tests based on the force and temperature profile predicted by the FE model. Defining a mathematical model which can be used as a built-in algorithm for tool wear prediction is very challenging and time consuming. Instead there is a possibility of using other factors such as stress distribution and temperature profile and correlate them to tool wear. In this research, the performance of different tool edge radius in cutting has been studied through experiments and in parallel Updated Lagrangian Models have been developed through ABAQUS/EXPLICIT for various cutting conditions, and experimental data was used to validate the data that has been generated from the finite element models. These models are very convenient to develop and capable of being applied for other types of material and cutting conditions. Thus, they represent an efficient way to reduce the amount of experiments needed to improve a tooling, the machining process, and thereby provide an effective way to increase the machining productivity of manufacturing companies. / Thesis / Master of Applied Science (MASc)

Thesis (MTech (Dental Technology Discipline))--Cape Peninsula University of Technology, 2007 / Practitioners often modify the powder:liquid ratio of polymethyl methacrylate resins (PMMA) to improve the handling properties of the material for certain procedures or because of personal preferences. While it is known that this influences the mechanical properties of unreinforced resin materials, little is known about its effect on glass fibre reinforced PMMA resin.

Georeferencing is an important task in terrestrial laser scanning (TLS) applications. It means transformation of the 3D data (point clouds) into an external coordinate system so that it can be combined with other spatial data. The aim of this study is to investigate the accuracy and precision of real-time updated free station (RUFS) as a georeferencing method in TLS applications, and to evaluate its efficiency. The RUFS is used in total station surveys, implies determination of the instrument position and orientation based on measurements of two or more backsight targets, whose coordinates are determined with Real Time Kinematic (RTK) GNSS. The field surveying was carried out in May and June 2010. A control point was established based on static GNSS measurements in order to have reference data to evaluate the accuracy of station coordinates. Three different configurations of 10 backsight targets were tested: the targets were evenly spread over the sectors of 200 and 100 gon on one arc and 100 gon on two arcs. The measurements were repeated ten times for each configuration. The precision and accuracy of the station position were then derived by processing the surveying data. The results show that with increasing the number of backsight points from 2 to 10, the planimetric precision of the station position improved from 6 to 3 mm; the height precision was at the level of 3−5 mm. The accuracy of the station position improved from 10 to 2 mm in planimetry, and from 28 to 11 mm in height. The time expense for one set of measurements with RUFS was approximately 15 minutes.

Thesis (MTech (Radiography))--Cape Peninsula University of Technology, 2011 / This thesis records a study undertaken by a radiography lecturer at a satellite campus of a University of Technology (UoT) in the Western Cape Province of South Africa. The study investigated the academic writing practices of first year Radiation Science learners and focused on an intervention to assist learners to enhance their academic writing competence. Three research questions were addressed: 1. What did radiography learners perceive to be the factors that enabled and constrained their academic writing competence during the first year of academic study?; 2. What were the 2010 first year learners’ perceptions of the changes in their academic writing following an academic writing intervention?; and 3. According to the 2010 first year lecturers, how did the academic writing of the learners change following the intervention? To answer these questions, the research comprised two qualitative approaches: firstly a case study approach, to gain an in-depth understanding of learner writing in radiography; then the insights gained allowed for the design of an appropriate academic writing intervention, carried out in two action research spirals. Thereafter the intervention was evaluated for its impact on learners’ writing competence. The findings and interpretations from this study culminated in a forward looking model that is recommended for use by radiography educators to enhance first year learners’ academic writing competence. The model reflects a zone for the optimal enhancement of academic writing competence for entry-level learners. This ‘zone’ is created in the region of overlap of three contributing factors: collaborative guidance and support, peer mentoring and technology. The model also represents applicable underlying theories (critical theory, constructivism, and academic literacies theory) which provide the theoretical framework for enhanced academic writing competence.

Finite element analysis of laminated shells using a three-noded flat triangular shell element is presented. The flat shell element is obtained by combining the Discrete Kirchhoff Theory (DKT) plate bending element and a membrane element similar to the Allman element, but derived from the Linear Strain Triangular (LST) element. Though this combination has been employed in the literature for linear static analysis of laminated plates, the results presented are not adequate to ascertain that the element would perform well in the case of static and dynamic analysis of general shells. The element is first thoroughly tested for linear static analysis of laminated plates and shells and is extended for free vibration, thermal, and geometrically nonlinear analysis. The major drawback of the DKT plate bending element is that the transverse displacement is not explicitly defined within the interior of the element. Hence obtaining the consistent mass matrix or the derivatives of the transverse displacement that are required for forming the geometric stiffness matrix is not straight forward. This problem is alleviated by borrowing shape functions from other similar elements or using simple displacement fields. In the present research, free vibration analysis is performed both by using a lumped mass matrix and a so called consistent mass matrix, obtained by borrowing shape functions from an existing element, in order to compare the performance of the two methods. The geometrically nonlinear analysis is performed using an updated Lagrangian formulation employing Green strain and Second Piola-Kirchhoff (PK2) stress measures. A linear displacement field is used for the transverse displacement in order to compute the derivatives of the transverse displacement that are required to compute the geometric stiffness or the initial stress matrix. Several numerical examples are solved to demonstrate the accuracy of the formulation for both small and large rotation analysis of laminated plates and shells. The results are compared with those available in the existing literature and those obtained using the commercial finite element package ABAQUS and are found to be in good agreement. The element is employed for two main applications involving large flexible structures. The first application is the control of thermal deformations of a spherical mirror segment, which is a segment of a multi-segmented primary mirror used in a space telescope. The feasibility of controlling the surface distortions of the mirror segment due to arbitrary thermal fields, using discrete and distributed actuators, is studied. This kind of study was required for the design of a multi-segmented primary mirror of a next generation space telescope. The second application is the analysis of an inflatable structure, being considered by the US Army for housing vehicles and personnel. The tent structure is made up of membranes supported by arches stiffened by internal pressure. The updated Lagrangian formulation of the flat shell element has been developed primarily for the nonlinear analysis of the tent structure, since such a structure is expected to undergo large deformations and rotations under the action of environmental loads like the wind and snow loads. The wind load is modeled as a nonuniform pressure load and the snow load as lumped concentrated loads. Since the direction of the pressure load is assumed to be normal to the current configuration of the structure, it changes as the structure undergoes deformation. This is called the follower action. As a result, the pressure load is a function of the displacements and hence contributes to the tangent stiffness matrix in the case of geometrically nonlinear analysis. The thermal load also contributes to the system tangent stiffness matrix. In the case of the thermal load this contribution is similar to the initial stress matrix and hence no additional effort is required to compute this contribution. In the case of the pressure load, this contribution (called the pressure stiffness) is in general unsymmetric but can be systematically derived from the principle of virtual work. The follower effects of the pressure load have been included in the updated Lagrangian formulation of the flat shell element and have been validated using standard examples in the literature involving deformation-dependent pressure loads. The element can be used to obtain the nonlinear response of the tent structure under wind and snow loads. / Ph. D.

In an era of digital convergence, people in related fields are devoted to activities of digitalization, especially in digital TV. This research is based on the Information System Success Model from Technology Acceptance Model (TAM) and aimed to understand the factors that affect user satisfaction and acceptance behavior. The researcher adopts the methodology of questionnaire survey. After statistical data analyses, the results show the main factor that influences MOD users¡¦ intention to use is perceived usefulness. Furthermore, perceived usefulness is influenced by perceived ease of use and user satisfaction. Three factors related to perceived ease of use and user satisfaction are program content quality, system quality and service quality of MOD. However, the influence of information quality is not significant. This research successfully constructs a technology acceptance model for MOD development and contributes for reference not only to future researches on users concerning innovative technologies but also to specific guidance for MOD operators to improve their services, expediting the development of digital TV in Taiwan.

Denna rapport kommer täcka utvecklingen av en Realtidsuppdaterad Dashboardför Flex Applications. Dashboarden kan ses som en interaktiv anslagstavla,ochär en ny moduli Flex Applications befintliga personaladministrationssystem. Under utvecklingen haräven en fördjupning inom ämnet informationsöverbelastninggjorts, då detta har relevans till designen av gränssnittet. Resultatet av detta visar på att det inte finns en given lösning utan snarare riktlinjer för hur designen bör se ut. Applikationen som skrevs till Dashboarden skapades med hjälp av språket TypeScript samt ramverket Angular 2. Applikationen skrevs först självständigt, avskiljt från Flex redan befintliga system.Dettaför att få en förståelse för hur TypeScript och Angular 2ska hanteras, och ävendärför att behovet av en direkt koppling till systemet ej behövdes från start. Applikationen kopplades sedansamman med det befintliga systemet för att kunna visualisera faktisk data. Detta blev lyckat och visade på att den valda systemdesignen fungerade som tänkt. / This report will be covering the creation of the Realtime-Updated Dashboard, made for Flex Applications. The Dashboard, which could be seen as an interactive pinboard, is a new product which will be implemented in Flex Applications existing system for employee administration. A deep-dive into the subject of information overload was also made during thedevelopment of the application. This was later used to question the design choices made. The results of this showed that there is no one correct way of designing an interface, but rather guidelines to help in certain situations. The application was written in the TypeScript language together with the framework Angular 2. The application was at first developed as a stand-alone project as there was no need for it to be integrated into the existing system from the start. This also gave a more relaxed environment while learning TypeScript and Angular2. The application was later integrated with the existing system. This integration was seen as a success as the handling of the data from the database worked as expected.

The goal of the present doctoral research is to create a theoretical framework and develop a numerical implementation for a shell finite element that can potentially achieve higher performance (i.e. combination of speed and accuracy) than current Continuum-based (CB) shell finite elements (FE), in particular in applications related to soft biological tissue dynamics. Specifically, this means complex and irregular geometries, large distortions and large bending deformations, and anisotropic incompressible hyperelastic material properties. The critical review of the underlying theories, formulations, and capabilities of the existing CB shell FE revealed that a general nonlinear CB shell FE with the abovementioned capabilities needs to be developed. Herein, we propose the theoretical framework of a new such CB shell FE for dynamic analysis using the total and the incremental updated Lagrangian (UL) formulations and explicit time integration. Specifically, we introduce the geometry and the kinematics of the proposed CB shell FE, as well as the matrices and constitutive relations which need to be evaluated for the total and the incremental UL formulations of the dynamic equilibrium equation. To verify the accuracy and efficiency of the proposed CB shell element, its large bending and distortion capabilities, as well as the accuracy of three different techniques presented for large strain analysis, we implemented the element in Matlab and tested its application in various geometries, with different material properties and loading conditions. The new high performance and accuracy element is shown to be insensitive to shear and membrane locking, and to initially irregular elements.

Due to the short time the updated National School Lunch Program standards have been in place since fall of 2012, few research studies have explored what effect these new standards have had on fruit and vegetable (F/V) consumption, particularly among elementary school students. Because the new standards require schools to offer students more F/V than before, researchers are interested to know if F/V consumption has indeed increased. The participants in the study were enrolled in a program to motivate students to eat more F/V – the Food Dudes program. The results of the data analysis found that most students, regardless of grade, were eating less F/V initially after the new standards were in place. However, the group of students receiving prizes from the Food Dudes program actually ate more F/V over time instead of less. Also, F/V consumption for the first spring under the new standards did not decrease as much as it had during the spring under the old standards. These results indicate that, despite initial declines in F/V consumption, students could be adjusting to the updated standards. Also, students who have participated in the incentives group of the Food Dudes program did not show a drop in F/V consumption, even during the first semester the new standards were in place. Future studies should look at the current F/V intake of students under the updated guidelines now that they have been in place for several school years, as well as at additional intervention programs to increase F/V consumption among this population.

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