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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.
1

The development of particle image velocimetry for water wave studies

Gray, Callum January 1989 (has links)
No description available.
2

Measurement Approach to the Comparisons of Career Anchor Models

Cai, Mengfei 13 June 2012 (has links) (PDF)
The career anchors concept is an approach to understanding career orientation and motivation. The original career anchor model was introduced by Schein in 1974. Several investigators have created revisions of the model to make it more useful. This dissertation is a continuation of the quest to evaluate the original model and the revised models with respect to empirical support. This study is the first of two studies in which measurement methods are devised to solve the psychometric problems of previous measures. In this study we create and test an "economic exchange" model to correct the problem of acquiescent bias. We test five career anchor models and this new scaling method against two sets of data. The first consists of data from 330 participants we collect in the present study, and the other is a set of correlation matrices from Barclay's dissertation meta-analysis of six previous studies from the literature. We find that the economic exchange method creates greater variances in the ratings (both within each person and across persons) as predicted, but the hypothesis of predicted increase in the range of correlation coefficients for this method is not supported. In its present form the economic exchange method is not found to be superior to the standard Likert scale method. In addition, the oppositionality of career anchor choices does not increase for older respondents as expected. From a confirmatory factor analysis test of goodness of fit of the five models against the six datasets of this dissertation and the six studies from Barclay's meta-analysis, we find no evidence for one best career anchors model. That is, the five competing theoretical models seem to each be "best" in some situations or populations.
3

Review and analysis of work sampling methods : the case of an automated labour performance measurement system using the work sampling method

Van Blommenstein, D., Matope, S., Van der Merwe, A.F. January 2011 (has links)
Published Article / This paper analyses work sampling and time study as work measurement methods with the view of employing them in an automated labour performance measurement system. These are compared with respect to Hawthorn effect, labour intensiveness, cost, tediousness and knowledge extensiveness. The analysis proves that work sampling is a better option for developing an automated labour performance measurement system that employs computer vision. Web cameras are used to feed real-time images to a central computer via USB extenders. The computer runs a standalone C++ application that uses a random function to establish when measurements are to be taken. The developed video camera footage is converted into a pixel matrix using OpenCV. This matrix is then filtered and analysed, enabling the tracking of a worker. The data generated is stored in text files. After the work sampling period has elapsed, the data is transferred into Microsoft Excel for analysis. Finally a report of the labour utilisation is generated in Microsoft Excel and then send to the analyst for review.
4

Clinical and epidemiological issues and applications of mammographic density

Assi, Valentina January 2014 (has links)
Mammographic density, the amount of radiodense tissue on a mammogram, is a strong risk factor for breast cancer, with properties that could be an asset in screening and prevention programmes. Its use in risk prediction contexts is currently limited, however, mainly due to di culties in measuring and interpreting density. This research investigates rstly, the properties of density as an independent marker of breast cancer risk and secondly, how density should be measured. The rst question was addressed by analysing data from a chemoprevention trial, a trial of hormonal treatment, and a cohort study of women with a family history of breast cancer . Tamoxifen-induced density reduction was observed to be a good predictor of breast cancer risk reduction in high-risk una ected subjects. Density and its changes did not predict risk or treatment outcome in subjects with a primary invasive breast tumour. Finally absolute density predicted risk better than percent density and showed a potential to improve existing risk-prediction models, even in a population at enhanced familial risk of breast cancer. The second part of thesis focuses on density measurement and in particular evaluates two fully-automated volumetric methods, Quantra and Volpara. These two methods are highly correlated and in both cases absolute density (cm3) discriminated cases from controls better than percent density. Finally, we evaluated and compared di erent measurement methods. Our ndings suggested good reliability of the Cumulus and visual assessments. Quantra volumetric estimates appeared negligibly a ected by measurement error, but were less variable than visual bi-dimensional ones, a ecting their ability to discriminate cases from controls. Overall, visual assessments showed the strongest association with breast cancer risk in comparison to computerised methods. Our research supports the hypothesis that density should have a role in personalising screening programs and risk management. Volumetric density measuring methods, though promising, could be improved.
5

Measurements of trackways as a method for assessing locomotion in dairy cows /

Telezhenko, Evgenij, January 2005 (has links) (PDF)
Licentiatavhandling (sammanfattning) Skara : Sveriges lantbruksuniversitet, 2005. / Härtill 2 uppsatser.
6

Measurement of Occupational Sound Exposure from Communication Headsets

Nassrallah, Flora G. January 2016 (has links)
Increased use of communication headsets found in various workplaces raises concerns regarding exposure to potentially hazardous noise levels. Current national and international standards specify a wide range of simple and specialized methods for the measurement of sound exposure under communication headsets. However, to date, quantitative data comparing the degree of agreement between the different measurement methods or their relative performance are lacking, and it is not known if occupational health and safety (OHS) or hearing loss prevention (HLP) stakeholders have the necessary training and equipment to integrate them in their daily practice. A three-step study addressing several knowledge gaps on this topic is presented in this thesis. First, a questionnaire survey distributed to OHS and HLP stakeholders has revealed that knowledge of specialized measurement techniques and access to the necessary equipment varies significantly depending on the training of the different professionals. There is therefore reason to specify several methods in measurement standards to meet the specific needs and expertise of the different stakeholders involved. Second, a series of experiments conducted with single and multiple expert participants indicated that the Type 1 artificial ear is not suited for sound exposure measurement with communication headsets, while Type 2 and Type 3.3 artificial ears are in good agreement with the acoustic manikin technique specified in the International standard ISO 11904-2. Finally, laboratory experiments were conducted to test the indirect calculation method proposed in the Canadian standard CSA Z107.56. Results revealed that the calculation method is suitable to identify possible situations of exposure over the regulatory limit (e.g. 85 dBA), but refinements are proposed to improve measurement accuracy. Overall, this thesis provides new knowledge to guide selection of the most suitable methods for the assessment of communication headset exposure taking into account expertise, access to equipment, and field logistic constraints. Results also have direct implications for future revisions of existing measurement standards. Finally, this work could be the basis for detailed guidelines on noise exposure measurements under communication headsets to better inform OHS and HLP professionals and ultimately prevent occupational noise-induced hearing loss.
7

Možnosti měření udržitelného rozvoje na regionální úrovni / Ways of sustainability measurement at the regional level

Kramulová, Jana January 2012 (has links)
This thesis deals with ways of sustainability measurement at the regional level. In the theoretical part apart from definition and evolution of the concept related fields and different approaches to sustainable development are presented. Further, data sources and suitable characteristics of ideal indicators are discussed. In the application part methods applicable to measuring sustainable development along with restraints and possible problematic areas are introduced. Subsequently, these methods are applied to individual regional levels according to CZ-NUTS classification (NUTS 1 to NUTS 3 levels and LAU 1 and LAU 2 levels). At the end of the thesis, the most suitable techniques of results' presentation are introduced. The aim of the thesis is to evaluate and assess the ways of practical use of mainly quantitative methods (statistical methods and modelling techniques) for analysis and measurement of regional development sustainability and to suggest the most convenient methods for individual regional levels. The thesis answers three research questions: if one method is useful for all "regional" levels; if it is better to assess sustainability from the point of view of pillar or capital approach; and finally, if it is for measuring of sustainability more proper one summarizing (composite) indicator or indicators' set including more indicators.
8

Zavedení metodiky měření pomocí technologie 3D skenování do strojírenské výroby / Introduction of measurement methodology using 3D scanning technology into mechanical production

Klein, Adam January 2020 (has links)
This thesis focuses on comparison of the commonly used method of tactile measurement with 3D scanning methods for their introduction into engineering production. The first part summarizes the current state with the description of measurement technologies with emphasis on 3D technologies and their versatile use. The second part presents a practical comparison of three types of measuring devices on a selected component of a bicycle. After numerical and graphical evaluation of the measurement results, these values are further statistically processed and the measurement uncertainties are calculated. The final part of the work evaluates the whole process and presents practical suggestions, options and recommendations.
9

Metodika pro kalibraci objemu nádob a nádrží / Methodology for calibration of containers and tanks

Vrátil, Šimon January 2013 (has links)
This diplomathesis work is dealing with a concept of volumetric calibration of vessels using the volumetric method. The analysis considers current regulations together with influence of uncertainties in measurements. The principal part of the thesis is analysis of metrological uncertainties resulting from application of various volumetric methods during the calibration process. A practical outcome from this research is development of metrological process for calibration of vessels that could be used by the accredited laboratories.
10

Numerické charakteristiky kvality obrazů / Numerical characteristics of digital image quality

Ivičič, Vojtěch January 2013 (has links)
This thesis deals with quality of digital images and with methods for measurement their numerical characteristics. Our attention is drawn to measurement of sharpness, as a main factor of image quality, in both space and spectral domain. For this reason, the Fourier and the discrete Fourier transform is described in one and two dimensions. Methods, presented in this work and implemented on attached CD, can be used for automatic image quality classification and autofocus of optical systems.

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