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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.
11

Evaluation of intelligent medical systems

Tilbury, Julian Bernard January 2002 (has links)
This thesis presents novel, robust, analytic and algorithmic methods for calculating Bayesian posterior intervals of receiver operating characteristic (ROC) curves and confusion matrices used for the evaluation of intelligent medical systems tested with small amounts of data. Intelligent medical systems are potentially important in encapsulating rare and valuable medical expertise and making it more widely available. The evaluation of intelligent medical systems must make sure that such systems are safe and cost effective. To ensure systems are safe and perform at expert level they must be tested against human experts. Human experts are rare and busy which often severely restricts the number of test cases that may be used for comparison. The performance of expert human or machine can be represented objectively by ROC curves or confusion matrices. ROC curves and confusion matrices are complex representations and it is sometimes convenient to summarise them as a single value. In the case of ROC curves, this is given as the Area Under the Curve (AUC), and for confusion matrices by kappa, or weighted kappa statistics. While there is extensive literature on the statistics of ROC curves and confusion matrices they are not applicable to the measurement of intelligent systems when tested with small data samples, particularly when the AUC or kappa statistic is high. A fundamental Bayesian study has been carried out, and new methods devised, to provide better statistical measures for ROC curves and confusion matrices at low sample sizes. They enable exact Bayesian posterior intervals to be produced for: (1) the individual points on a ROC curve; (2) comparison between matching points on two uncorrelated curves; . (3) the AUC of a ROC curve, using both parametric and nonparametric assumptions; (4) the parameters of a parametric ROC curve; and (5) the weight of a weighted confusion matrix. These new methods have been implemented in software to provide a powerful and accurate tool for developers and evaluators of intelligent medical systems in particular, and to a much wider audience using ROC curves and confusion matrices in general. This should enhance the ability to prove intelligent medical systems safe and effective and should lead to their widespread deployment. The mathematical and computational methods developed in this thesis should also provide the basis for future research into determination of posterior intervals for other statistics at small sample sizes.
12

Experimentální ověření parametrů vodní mikroturbíny / Testing of micro water turbine

Zríni, Miroslav January 2018 (has links)
The aim of the diploma thesis is to measure and subsequently to evaluate microturbine characteristics. This is a new type of turbine, which was designed in the diploma thesis and is based on the theory of waterwheels. It is designed for low heads and low flow, where conventional turbines are not suitable. Taking advantage of this low heads area will be very important in the future as the hydroenergetic potential is getting gradually exhausted. The turbine has two ways of regulation - turning blades and shifting the drawer. In the first phase, two complex measurements were performed. The next step was to process the measured data gradually in three programs. The result is the rendering of the characteristics that describe the hydraulic parameters of the turbine. The last chapter shows the design proposals for automatic regulation.
13

Additive polynomial flows on tori in positive characteristic

Ustian, Alex L. 25 June 2012 (has links)
No description available.
14

Orbifold euler characteristic of global quotients

Hsia, Kwok-tung., 夏國棟. January 2010 (has links)
published_or_final_version / Mathematics / Master / Master of Philosophy
15

Natural frequency based damage identification of beams using piezoelectric materials

Zhao, Shengjie 24 December 2015 (has links)
Following the studies of natural frequency based damage detection methods, an advanced technique for damage detection and localization in beam-type structures using a vibration characteristic tuning procedure is developed by an optimal design of piezoelectric materials. Piezoelectric sensors and actuators are mounted on the surface of the host beam to generate excitations for the tuning via a feedback process. The excitations induced by the piezoelectric effect are used to magnify the effect of the damage on the change of the natural frequencies of the damaged structure to realize the high detection sensitivity. Based on the vibration characteristic tuning procedure, a scan-tuning methodology for damage detection and localization is proposed. From analytical simulations, both crack and delamination damage in the beams are detected and located with over 20% change in the natural frequencies. Finite element method (FEM) simulations are conducted to verify the effectiveness of the proposed methodology. / October 2016
16

Discrete event dynamic systems in max-algebra : realisation and related combinatorial problems

Murfitt, Louise January 2000 (has links)
No description available.
17

Factors affecting individuals' competency in organisations using knowledge creation model and HRM practices

Alainati, Shaikhah J. January 2015 (has links)
This thesis is on competent individuals the essential organisational resource, particularly for knowledge work. Managers need to attend to the development of incompetent individuals. What constitutes individuals’ competency (IC), how can it be developed through better human resource management (HRM), and how is it implemented for knowledge management (KM) all needs theoretical explanation. There is disagreement in the research literature on the effect of factors such as education, training, personal characteristic, and environment on IC. The aim of this research is to explore these factors in the context of KM as facilitated by HRM. An exploratory sequential mixed methods and triangulation approach is used. The first phase qualitative research explores IC from employees’ perspective. The findings of this phase are used in the second quantitative phase to develop quantifiable variables. That needs to be further explored. The findings of both phases are triangulated; data consistency between the two phases indicates that the measuring instruments are accurate, which strengthened the thesis argument. The research data is collected from Kuwait, which like any other country suffers from incompetent employees. Forty one interviews were conducted for the qualitative phase and 763 survey questionnaires were collected for the quantitative phase. Knowledge of IC as revealed in the literature suggests four contentious factors that affect it: education, training, personal characteristics and environment, each of which has a prior and on-job occurrence. This thesis postulates: (a) that rather than individual factors, these four factors affect IC holistically; (b) that these four factors apply to each of the four modes of the knowledge creation model (KCM); and (c) that HRM has a significant role in developing IC for KM. Empirical results of the hypothesis show a statistically significant positive effect for each of the four factors on IC and that the effect is holistic. This finding supports the developed model of IC. Therefore, the research hypotheses are accepted and the IC model is proven to be fit. Also, when statistically operationalizing the four factors on the KCM, it was found that not all four factors are absorbed by each of the four modes of the KCM, thus revealing its limitation in practice. Finally, HRM is proven to affect IC and the KCM positively. Nevertheless, this relies on HRM being empowered by the organisation. This thesis makes several contributions. It contributes empirical evidence of the positive and holistic effect of education, training, personal characteristics and environment on IC. This leads to the second contribution that these four factors of IC, as new knowledge, cannot all be processed within a particular mode of the KCM; rather it selectively absorbs particular factors better than others. Thus, the theoretical knowledge creation argument differs from the actual empirical findings. These findings lead to significant contribution to HRM practice. For instance, in hiring or promoting individuals, managers should consider the four theoretically derived and empirically confirmed IC factors, education, training, personal characteristics (PC) and environment.
18

Multiplicativity Of The Euler Characteristic

January 2015 (has links)
Covering maps and fibrations of spaces fulfilling certain technical conditions are known to satisfy a multiplicative formula relating the Euler characteristic of the domain to that of the codomain. An open question posed by Albrecht Dold in 1980 asks in general when this is true and can be stated as: for which classes of maps is it true that if χ(X) denotes the Euler characteristic of a space X, and if f : X → Y has the property that the Euler characteristic of the preimage of y is k for all y ∈ Y and for some integer k, the multiplicative formula χ(X) = k · χ(Y ) holds? A corroborative answer is given herein for simplicial maps of finite simplicial complexes, while counterexamples are constructed for cellular maps of finite CW complexes, continuous maps of closed topological manifolds, and even smooth maps of smooth manifolds. / 1 / Kelley Brook Johnson
19

Measuring value added characteristics in feeder cattle

Mathews, Crystal Dawn 15 May 2009 (has links)
According to the USDA, there were 52.7 million marketings of cattle through live and internet auction markets and other venues in 2005. With the national average herd size at 43 head, most producers have limited bargaining power when it comes to marketing and auctioning their cattle. This has led to the birth of numerous value added cattle programs in the U.S. Value added programs are named as such, because they add additional value to the cattle before they are sold, but this value is difficult to quantify. The objective of this research was to measure the value of characteristics of feeder cattle sold through auction markets and special source verified feeder cattle sales, specifically the value of participating in these value added programs. Data over seven years from regular and special feeder cattle sales at Joplin Regional Stockyards were used. The effects of explanatory variables on sale price were analyzed using ordinary least squares regression hedonic model. Type of sale, seasonality, cyclical effects, lot size, weight, breed type, sex, commingling, fed cattle futures price, and corn price were all found to have an impact on the sale price of feeder cattle. Feeder calves sold through MFA Health Track Beef Alliance and other value added programs received a premium over those calves that sold through regular sales and the premiums for MFA and other value added programs were statistically different. Commingled lots of feeder cattle received a discount in comparison with non-commingled lots, but a lot size of 17 head would offset the negative effect of commingling. The predictive power of the hedonic model was tested using out of sample forecasting. The mean absolute percent error and root mean square error are indicators of the ability of the model to forecast sale price based on the measured impact of the explanatory variables. When the hedonic model was used for forecasting the out of sample data, the MAPE was 7.84 and the RMSE was 10.48.
20

The Influence of the Personality Characteristic on Job Satisfaction, Organization Commitment and Turnover Tendency among the Different Generation Employees

Wang, Mei-chuan 10 September 2007 (has links)
This research will focus on the following items. 1. The difference of the personality characteristic among different generation employees. 2. The difference in personal variation for personality characteristic, organization commitment, job satisfaction, and turnover tendency. 3. The influence of the personality characteristic on organization commitment, job satisfaction, and turnover tendency. 4. To discuss the relationship of the personality characteristic on organization commitment, job satisfaction, and turnover tendency whether interfered by the different generation. The target of research was the employees who work in domestic enterprises, and adop a questionnaire method to collection data, which sending out 1,051 questionnaires, and recovering 962. The recovery rate reaches to 92%, after eliminating 26 invalid questionnaires, we got 936 valid questionnaires, and the valid recovery rate was 89%. We will make analysis through the method includes descriptive analysis, factor analysis, letter degree analysis, independent sample t test, one way ANOVA, Pearson¡¦s correlation analysis and multiple regression analysis. The research finding as follows. 1. The personality characteristic among different generation employees have no obvious difference. There is only the difference in degree between the inner-controlled and outer-controlled personality characteristic. There is no absolute dichotomization, and most people are being between the both. There is also no absolute boundary between A type personality and B type personality, most people may own two kinds of personality characteristics in the meantime, just one kind of them is more obvious. 2. There are quite differences among the personality characteristic, organization commitment, job satisfaction, and turnover tendency, which caused by personal variable (include sex, age, marriage appearance, level of education, work seniority and job title). 3. When the employee tends to inner-controlled personality characteristic, the degree of job satisfaction and organization commitment is higher. 4. When the employee tends to inner-controlled personality characteristic, the turnover tendency becomes lower. 5.When the employee tends to ¢Ï type personality characteristic, the degree of job satisfaction and organization commitment, the turnover tendency are more high. 6. The relationship between inner-controlled and outer-controlled personality characteristic, and job satisfaction was obviously interfered by "Generation". 7. The relationship between inner-controlled and outer-controlled personalitycharacteristic, and organization commitment was obviously interfered by "Generation". 8. The relationship between inner-controlled and outer-controlled personality characteristic, and turnover tendency was not interfered by "Generation". 9.The relationship between ¢Ï type personality characteristic, job satisfaction, organization commitment and turnover tendency was not interfered by "Generation".

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