Let G be a directed graph with a total labeling. The additive arc-weight of an arc xy is the sum of the label on xy and the label on y. The additive directed vertex-weight of a vertex x is the sum of the label on x and the labels on all arcs with head at x. The graph is additive arc magic if all additive arc-weights are equal, and is additive directed vertex magic if all vertex-weights are equal. We provide a complete characterization of all graphs which permit an additive arc magic labeling. A complete characterization of all regular graphs which may be oriented to permit an additive directed vertex magic labeling is provided. The definition of the subtractive arc-weight of an arc xy is proposed, and a correspondence between graceful labelings and subtractive arc magic labelings is shown.

The Frobenius-Perron operator acting on integrable functions and the Koopman operator acting on essentially bounded functions for a given nonsingular transformation on the unit interval can be shown to have cyclic spectrum by referring to the theory of lattice homomorphisms on a Banach lattice. In this paper, it is verified directly that the peripheral point spectrum of the Frobenius-Perron operator and the point spectrum of the Koopman operator are fully cyclic. Under some restrictions on the underlying transformation, the Frobenius-Perron operator is known to be a well defined linear operator on the Banach space of functions of bounded variation. It is also shown that the peripheral point spectrum of the Frobenius-Perron operator on the functions of bounded variation is fully cyclic.

This thesis is a pilot study on the subsampling methods for robust estimation in regression models when there are possible outliers in the data. Two basic proposals of the subsampling method are investigated. The main idea is to identify good data points through fitting the model to randomly chosen subsamples. Subsamples containing no outliers are identified by good fit and they are combined to form a subset of good data points. Once the combined sets containing only good data points are identified, classical estimation methods such as the least-squares method and the maximum likelihood method can be applied to do regression analysis using the combined set. Numerical evidence suggest that the subsampling method is robust against outliers with high breakdown point, and it is competitive to other robust methods in terms of both robustness and efficiency. It has wide application to a variety of regression models including the linear regression models, the non-linear regression models and the generalized linear regression models. Research is ongoing with the aim of making this method an effective and practical method for robust inference on regression models.

This work is directed towards linear and nonlinear three dimensional magnetostatic field analysis and computation in electrical devices. Question regarding the validity and uniqueness of numerical field solutions, obtained on the basis of the curl curl approach, has been resolved through analytical proofs, numerical demonstrations, as well as experimental verifications. A nonlinear three dimensional magnetostatic field formulation is developed using the Newton-Raphson approach in conjunction with the three dimensional finite element method for inclusion of nonlinearities in laminated iron cores under saturated conditions. The developed, formulation was successfully implemented and applied to a practical example with considerable magnetic saturation. A method, for the calculation of saturated device winding inductance, is presented. This method is based on an energy perturbation technique and was successfully applied numerically and verified experimentally. Two methods for the calculation of forces on conductor segments as well as magnetized ferrous parts are developed in conjunction with the three dimensional finite element vector potential method. The proximity effect, resulting from considering small or large solution volumes on the field distribution, and the calculated values of force, is examined. It is demonstrated that a large solution volume, with Dirichlet boundary conditions imposed on the outermost surfaces of the volume considered, yield practically the same result, as when the Neumman boundary conditions were imposed on such surfaces. This result is of a considerable significance, from a practical standpoint, since the imposition of Dirichlet type boundary conditions on the outermost boundaries of the volume considered, results in a fewer number of equations to be solved. This, in turn, results in savings of the total execution time and memory costs required for the solution of large problems of two dimensional, and three dimensional fields by finite elements. It is demonstrated that three dimensional field solutions reduce to the corresponding two dimensional field solutions for problems which are inherently two dimensional in nature due to axial symmetry. This result provides a further verification of the validity of the three dimensional finite element formulation presented in this work. / Ph. D.

The effect of structural optimization on control of stiffened laminated composite structures is considered. The structural optimization considered here, is the maximization of structural frequencies of the structure subject to maximum weight and frequency separation constraints and an upper bound on weight. The number of plies with a given orientation and the stiffener areas form the two sets of design variables. As the number of plies is restricted to integer values, the optimization problem considered belongs to the class of nonlinear mixed integer problems (NMIP). Several efficiency measures are proposed to reduce the computational cost for solution of the optimization problem. Savings in computer time due to each of the measures is discussed. The control problem is solved using the independent modal space control technique. This technique greatly simplifies the evaluation of the sensitivity of the performance index with respect to the individual frequencies. The effect of different optimization schemes on the control performance is considered. To reduce the probability, that conclusions drawn from numerical results, are purely coincidental, a large number of cases has been studied. It has been concluded that sufficient improvement in control performance can be achieved through structural optimization. / Ph. D.

The 1990s ushered in what historian Susan Stryker describes as “a tremendous burst of new transgender activism” in the United States. Concomitantly, the success of Star Trek: The Next Generation led to a renaissance of US science fiction television. This dissertation asks, what is the relation between transgender (trans) politics and US science fiction (sf) television from 1990 to the present? The theoretical framework is Trans/Elemental feminism, a new paradigm developed in the dissertation. The method is multiperspectival cultural studies, which considers how the production, content, and reception of media texts and their metatexts collectively determine the texts’ meaning. The data include trade articles about the television industry; published interviews with producers; 3,175 hours of televisual content; commercial advertisements for television programs; films, novels, and webisodes (Web episodes) in selected media franchises; professional reviews; online discussion boards; fan fiction; and fan videos. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2015 / FAU Electronic Theses and Dissertations Collection

This work investigates energy-efficient approximate computation for solving differential equations. It extends the analog computing techniques to a new paradigm: continuous-time hybrid computation, where both analog and digital circuits operate in continuous time. In this approach, the time intervals in the digital signals contain important information. Unlike conventional synchronous digital circuits, continuous-time digital signals offer the benefits of adaptive power dissipation and no quantization noise. Two prototype chips have been fabricated in 65 nm CMOS technology and tested successfully. The first chip is capable of solving nonlinear differential equations up to 4th order, and the second chip scales up to 16th order based on the first chip. Nonlinear functions are generated by a programmable, clockless, continuous-time 8-bit hybrid architecture (ADC+SRAM+DAC). Digitally-assisted calibration is used in all analog/mixed-signal blocks. Compared to the prior art, our chips makes possible arbitrary nonlinearities and achieves 16 times lower power dissipation, thanks to technology scaling and extensive use of class-AB analog blocks. Typically, the unit achieves a computational accuracy of about 0.5% to 5% RMS, solution times from a fraction of 1 micro second to several hundred micro seconds, and total computational energy from a fraction of 1 nJ to hundreds of nJ, depending on equation details. Very significant advantages are observed in computational speed and energy (over two orders of magnitude and over one order of magnitude, respectively) compared to those obtained with a modern MSP430 microcontroller for the same RMS error.

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University of Macau / Faculty of Science and Technology / Department of Civil and Environmental Engineering

In this thesis, we focus on a forecasting tool, Martingale Model of Forecast Evolution (MMFE), to model the evolution of forecasts in a production-distribution system. Additive form is performed to represent the evolution process. Variance-Covariance (VCV) matrix is defined to express the forecast updates. The selected demand pattern is stationary and it is normally distributed. It follows an Autoregressive Order-1 (AR(1)) model. Two forecasting procedures are selected to compare the MMFE with. These are MA (Moving average) and ES (Exponential smoothing) methods. A production-distribution model is constructed to represent a two-stage supply chain environment. The performance measures considered in the analyses are the total costs, fill rates and forecast accuracy observed in the operation of the production-distribution system. The goal is to demonstrate the importance of good forecasting in supply chain environments.