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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.
281

Microwave-assisted synthesis of non-oxide ceramic powders

Hassine, Nabile January 1994 (has links)
No description available.
282

A Monte-Carlo approach to tool selection for sheet metal punching and nibbling

Summad, Emad January 2001 (has links)
Selecting the best set of tools to produce certain geometrical shapes/features in sheet metal punching is one of the problems that has a great effect on product development time, cost and achieved quality. The trend nowadays is, where at all possible, to limit design to the use of standard tools. Such an option makes the problem of selecting the appropriate set of tools even more complex, especially when considering that sheet metal features can have a wide range of complex shapes. Another dimension of complexity is limited tool rack capacity. Thus, an inappropriate tool selection strategy will lead to punching inefficiency and may require frequent stopping of the machine and replacing the required tools, which is a rather expensive and time consuming exercise. This work demonstrates that the problem of selecting the best set of tools is actually a process of searching an explosive decision tree. The difficulty in searching such types of decision trees is that intermediate decisions do not necessarily reflect the total cost implication of carrying out such a decision. A new approach to solve such a complex optimisation problem using the Monte Carlo Simulation Methods has been introduced in this thesis. The aim of the present work was to establish the use of Monte Carlo methods as an "assumptions or rule free" baseline or benchmark for the assessment of search strategies. A number of case studies are given, where the feasibility of Monte Carlo Simulation Methods as an efficient and viable method to optimise such a complex optimisation problem is demonstrated. The use of a Monte Carlo approach for selecting the best set of punching tools, showed an interesting point, that is, the effect of dominant "one-to-one" feature/tool matches on the efficiency of the search. This naturally led on to the need of a search methodology that will be more efficient than the application of the Monte Carlo method alone. This thesis presents some interesting speculations for a hybrid approach to tool selection to achieve a better solution than the use of the Monte Carlo method alone to achieve the optimum solution in a shorter time.
283

The Apparatus

de Rooy, Shaun 21 July 2016 (has links)
This document, in conjunction with the body of work within the exhibition The Apparatus, challenges the dichotomy of practical and theoretical definitions of utility. Presented in two opposing formats, the work within this thesis attempts to re-examine the concept of utility as a spectrum, rather than in the binary structure of the practical (functional) and theoretical (aesthetical) methods of encounter. / October 2016
284

Lithic raw material procurement through time at Swartkrans: earlier to Middle Stone Age

Sherwood, Nicole Leoni 08 January 2014 (has links)
A dissertation submitted to the School of Geography, Archaeology and Environmental Studies, Faculty of Science University of the Witwatersrand, Johannesburg for the degree of Master of Science. Johannesburg 2013. / Tool manufacturing played a major role in the development and evolution of our species, and by studying the tools left behind by our ancestors we gain valuable insight into their development and behaviours through time. This study was conducted on the Swartkrans Oldowan (2.2 - 1.7 Ma), early Acheulean (1.5 - 1 Ma), and Middle Stone Age (<110 ka) assemblages to determine the degree of lithic raw material selectivity for making stone tools, and if they practiced ever increasing selection towards better quality stone over time. The presence of quality selection was determined by comparing the various Swartkrans assemblages with experimentally created lithic tools from rock types found in the study area. Three main characteristics that determine selection of rock types were isolated: flaking predictability, durability and sharpness. Analysis of the data provided further evidence that our early stone tool making ancestors had the ability to understand how different rock types behave when knapped and tended to select rocks that had a high flaking predictability, high durability and could produce fairly sharp edges. It was also apparent that they could identify features that diminish the above mentioned characteristics. Variables such as the impurity encounter rate, fracture encounter rate, weathering, grain size and homogeneity were semiquantitatively recorded for the three techno-complexes at Swartkrans and compared to each other to help identify the degree of selectivity that was practiced over time. The data revealed that selection for quality of lithic raw materials was practiced to some extent during the Oldowan and improved slightly in the early Acheulean. The most marked selection for quality was seen for the Middle Stone Age when modern humans used the site. These results indicate that as time progressed in the Sterkfontein valley, and the stone tool technologies became more complex, so too did the selective pressures and thus an increase in selection for quality lithic raw materials over the course of time.
285

Integrating requirements authoring and design tools for heterogeneous and multicore embedded systems. : Using the iFEST Tool Integration Framework

Wolvers, Adrianus Hendrikus Cornelis January 2013 (has links)
In today’s practical reality there are many different tools being used in their respective phases of thesystem development lifecycle. Every tool employs its own underlying metamodel and these metamodelstend to vary greatly in size and complexity, making them difficult to integrate. One solution to overcomethis problem is to build a tool integration framework that is based on a single, shared metamodel.The iFEST project aims to specify and develop such a tool integration framework for tools used in thedevelopment of heterogeneous and multi-core embedded systems. This framework is known as the iFESTTool Integration Framework or iFEST IF.The iFEST IF uses Web services based on the Open Services for Lifecycle Collaboration (OSLC)standards and specifications to make the tools within the tool chain communicate with each other. Tovalidate the framework, an industrial case study called ‘Wind Turbine’, using several embedded systemstools, has been carried out. Tools used to design, implement and test a controller for a wind turbine havebeen integrated in a prototype tool chain. To expose tools’ internal data through Web services, a tooladaptor is needed. This work reports on the development of such a tool adaptor for the RequirementsManagement module of HP Application Lifecycle Management (ALM), one of the tools used in the WindTurbine industrial case study. A generalization of the challenges faced while developing the tool adaptoris made. These challenges indicate that, despite having a tool integration framework, tool integration canstill be a difficult task with many obstacles to overcome. Especially when tools are not developed with tool integration in mind from the start. / Idag existerar det en mängd olika verktyg som kan appliceras i respektive fas isystemutvecklings livscykel. Varje verktyg använder sin egna underliggande metamodell. Dessametamodeller kan variera avsevärt i både storlek och komplexitet, vilket gör dem svåra attintegrera. En lösning på detta problem är att bygga ett ramverk för verktygsintegration sombaseras på en enda, gemensam metamodell.iFEST-projektets mål är att specificera och utveckla ett ramverk för verktygsintegration förverktyg som används i utvecklingen av heterogena och multi-core inbyggda system. Dettaramverk benämns iFEST Tool Integration Framework eller iFEST IF.iFEST IF använder webbtjänster baserade på en standard som kallas OSCL, Open Services forLifecycle Collaboration samt specifikationer som gör att verktygen i verktygskedjan kankommunicera med varandra. För att validera ramverket har en fallstudie vid namn ”WindTurbine” gjorts med flertal inbyggda systemverktyg. Verktyg som används för att designa,implementera och testa en styrenhet för vindturbiner har integrerats i prototyp av enverktygskedja. För att bearbeta och behandla intern data genom webbtjänster behövs enverktygsadapter. Detta arbete redogör utvecklingen av en verktygsadapter förkravhanteringsmodulen HP Application Lifecycle Management (ALM), ett av de verktyg somanvänts i fallstudien av vindturbinen. En generalisering av de utmaningar som uppstod underutvecklingen av verktygsadaptern har genomförts. Dessa utmaningar indikerar att, trots att detfinns ett ramverk för verktygsintegration så är verktygsintegration fortfarande vara en svåruppgift att få bukt med. Detta gäller särskilt när verktyg inte är utvecklade med hänsyn tillverktygsintegration från början. / ARTEMIS iFEST
286

Qualitative and Quantitative Management Tools Used by Financial Officers in Public Research Universities

Trexler, Grant 1961- 14 March 2013 (has links)
This dissertation set out to identify effective qualitative and quantitative management tools used by financial officers (CFOs) in carrying out their management functions of planning, decision making, organizing, staffing, communicating, motivating, leading and controlling at a public research university. In addition, impediments to the use of these tools were identified which may assist in breaking down barriers to the implementation of these tools within higher education. The research endeavor also provided additional significance through the CFOs identifying benefits from the use of quantitative and qualitative management tools. Finally, the study undertook the task of identifying quantitative and qualitative management tools the important to public research university CFOs in carrying out their management functions in the future. In this study, the Delphi method was used to gain consensus from a panel of fifteen public research university CFOs who were experts on qualitative and quantitative management tools. The experts were self-identified through their response to a questionnaire on their use of the management tools and represented 12 different states. Due to the nature of the research, a computer-based Delphi method was used to facilitate a four round, electronically based Delphi study. The questionnaires were based upon a review of the literature and tested by a pilot group of higher education CFOs. Through a series of four electronic questionnaires, the Delphi panel identified twenty-three qualitative and quantitative management tools which they believe are moderately effective for use by public research university CFOs in carrying out their functions of planning, decision making, organizing, staffing, communicating, motivating, leading and controlling. Additionally, the panel of experts identified sixteen barriers/impediments to the use of qualitative and quantitative tools in carrying out the above functions. The panel also identified eighteen benefits that the tools provide to public research university CFOs in carrying out their management functions. Finally, the Delphi panel identified three qualitative and quantitative management tools that will be highly important, and twenty qualitative and quantitative management tools that the panel of experts considered to be important, for public research university CFOs in carrying out their management functions in the future. This dissertation study is significant because the results are expected to provide public research university CFOs qualitative and quantitative management tools that they may use to assist them in carrying out their management functions. The barriers/impediments and benefits noted also provide CFOs with knowledge to assess whether the tools can be used at their institutions, knowing the specific climate and culture which exists. The qualitative and quantitative management tools which were identified as being important in the future can serve as a guide to develop training programs to enhance the knowledge of public research university CFOs.
287

En beskrivning av manuellt test : Svagheter och styrkor med och utan stöd avett testverktyg

Artursson Wissa, Ulrika January 2011 (has links)
Test is an area in system development. Test can be performed manually or automated. Test activities can be supported by Word documents and Excel sheets for documenting and executing test cases and as well for follow up, but there are also new test tools designed to support and facilitate the testing process and the activities of the test. This study has described manual test and identified strengths and weaknesses of manual testing with a testing tool called Microsoft Test Manager (MTM) and of manual testing using test cases and test log templates developed by the testers at Sogeti. The result that emerged from the problem and strength analysis and the analysis of literature studies and firsthand experiences (in terms of creating, documenting and executing test cases) addresses the issue of the following weaknesses and strengths. Strengths of the test tool is that it contains needed functionality all in one place and it is available when needed without having to open up other programs which saves many steps of activity. Strengths with test without the support of test tools is mainly that it is easy to learn and gives a good overview, easy to format text as desired and flexible to changes during execution of a test case. Weaknesses in test with the support of test tools include that it is difficult to get a good overview of the entire test case, that it is not possible to format the text in the test steps. It is as well not possible to modify the test steps during execution. It is also difficult to use some of the test design techniques of TMap, for example a checklist, when using the test tool MTM. Weaknesses with test without the support of the testing tool MTM is that the tester gets many more steps of activities to do compared to doing the same activities with the support of the testing tool MTM. There is more to remember because the documents the tester use are not directly linked. Altogether the strengths of the test tool stands out when it comes to supporting the testing process.
288

Integrated Inspection for Precision Part Production

Chen, Austin Hua-Ren 06 April 2006 (has links)
This research develops a methodology for enhancing the performance of a precision computer numerically controlled (CNC) machine tool. The ability to precisely maintain the desired relative position between the cutting tool and the workpiece along the cutting trajectory has a major impact on the dimensional accuracy of the finished part. It is important to ensure that the workpiece geometry satisfies tolerances before removing it from the machine tool. Traditional manufacturing procedures do not catch bad parts until the post-process inspection stage, when the part has already been removed from the setup. Subsequent attempts at re-machining require that the workpiece be re-fixtured back on the machine which often introduces more error into the process. The objective of this research is to develop a methodology that integrates pre-process calibration and process-intermittent gaging to enhance the ability of a two-axis vertical turning center to cut a circular arc. The developed methodology is straightforward and integrates the usage of commercially available instrumentation such as the ball bar and on-machine probe for error identification, prediction, and compensation.
289

Morphological variation of bolen haftable bifaces function and style among chipped-stone artifacts from the early holocene southeast /

Bissett, Thaddeus G. Faught, Michael K. January 2003 (has links)
Thesis (M.S.)--Florida State University, 2003. / Advisor: Dr. Michael K. Faught, Florida State University, College of Arts and Sciences, Dept. of Anthropology. Title and description from dissertation home page (viewed Apr. 6, 2004). Includes bibliographical references.
290

Application of electrical heating in hot-machining.

Lo, Kwok-chuen. January 1972 (has links)
Thesis--M. Sc.(Eng.), University of Hong Kong. / Offset from typescript.

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