Title of dissertation: GLOBAL OPTIMIZATION OF FINITE MIXTURE MODELS Jeffrey W. Heath Doctor of Philosophy, 2007 Dissertation directed by: Professor Michael Fu Robert H. Smith School of Business & Professor Wolfgang Jank Robert H. Smith School of Business The Expectation-Maximization (EM) algorithm is a popular and convenient tool for the estimation of Gaussian mixture models and its natural ext...

We introduce a new randomized method called Model Reference Adaptive Search (MRAS) for solving global optimization problems. The method works with a parameterized probabilistic model on the solution space and generates at each iteration a group of candidate solutions. These candidate solutions are then used to update the parameters associated with the probabilistic model in such a way that the ...

For an interior permanent magnet synchronous motor (IPMSM) control system, the actual maximum torque per ampere (MTPA) trajectory may deviate from the ideal one with parameter variances, and thus the system may not obtain the maximum torque output. In view of this problem, a novel parameter identification method based on the model reference adaptive system (MRAS) is proposed in this paper. In t...

Model Reference Adaptive System (MRAS) based techniques are one of the best methods to estimate the rotor speed and position due to its performances and straight forward stability approach. In this paper, we propose a new robust MRAS scheme based on sliding mode techniques to estimated the rotor speed of a Surface Permanent Magnet Synchronous Motor (SPMSM). Furthermore, an Estimator/Observer sw...

BACKGROUND There has been an increasing interest in use of mineralocorticoid receptor antagonists (MRAs) in patients with heart failure with preserved ejection fraction (HFPEF). However, a comprehensive evaluation of MRA effects on left ventricular (LV) structure and function in these patients is lacking. In this meta-analysis, we evaluated the effects of MRAs on LV structure and function among...

The Expectation-Maximization (EM) algorithm is a very popular optimization tool in model-based clustering problems. However, while the algorithm is convenient to implement and numerically very stable, it only produces solutions that are locally optimal. Thus, EM may not achieve the globally optimal solution to clustering problems, which can have a large number of local optima. This paper introd...

Streaming video on the World Wide Web is being widely deployed, and workplace training and distance education are key applications. The ability to annotate video on the Web can provide significant added value in these and other areas. Written and spoken annotations can provide ‘in context’ personal notes and can enable asynchronous collaboration among groups of users. With annotations, users ar...

Background: This study examined: (a) whether medical record administrators (MRAs) properly understand and apply a cancer registration manual; (b) weaknesses in cancer registration: and (c) factors influencing the accuracy of cancer registration. Methods: MRAs dealing with cancer registration in 81 national member hospitals were asked by mail to answer 17 questions about cancer information among...

Product information given in purchase situations influences purchase behavior. In online purchase situations, the use of recommendation agents increases the value of product information as information becomes adaptive and thus more relevant to consumers’ information needs. Correspondingly, mobile recommendation agents (MRAs) may also increase the value of product information in bricks-and-morta...