Thesis ((PhD)--Stellenbosch University, 2015. / ENGLISH ABSTRACT: This dissertation proposes a multi-mode antenna element excited through a multiconductor feed. It is shown that each of the orthogonal transverse electromagnetic modes supported by the antenna feed results in a unique radiated far-field pattern that collectively allow for nearhemispherical field-of-view coverage. Three multi-mode antenna designs are presented: a dual-mode antenna, integrating a single linearly polarised dipole antenna with a co-located monopole, as well as two quad-mode antenna designs integrating two dual-polarised dipole elements with a co-located monopole element. The dual-mode antenna is excited through a balanced transmission line feed supporting both differential- and common-mode signals that, respectively, result in typical dipole-over-ground and monopole radiated far-field patterns. The quad-mode antennas are each fed through a quadraxial transmission line allowing for excitation through four orthogonal transverse electromagnetic port modes. To characterise the multi-mode response of the multi-mode antennas, generalised transformations are derived by which the multi-mode S-parameters and radiated far-fields can be calculated from the S-parameters and far-fields corresponding to single-ended excitations. These transformations are implemented to validate the response of a dual-mode and quad-mode antenna design through measurements. An equivalent network representation for active multi-mode antennas is presented, including generalised transformations relating the multi-mode signal and noise response of the low-noise amplifiers to the two-port S-parameters and noise parameters of the low-noise amplifiers. Through the use of classical beamforming algorithms, the performance of an active dual-mode and quadmode antenna is presented. In the case of the active dual-mode antenna, it is shown that through the added use of common-mode signals, a variation in sensitivity of less than 50% is achieved in the E-plane. Similarly, the additional excitation modes supported by the active quad-mode antenna is shown to result in a significant improvement in the polarimetric capabilities over the field-of-view coverage. / AFRIKAANSE OPSOMMING: Hierdie proefskrif stel ’n multimodale antenna element voor wat deur ’n multi-geleier transmissielyn gevoer word. Dit word gewys dat elk van die ortogonale transversale elektromagnetiese opwekkingsmodusse wat deur die antenna voer ondersteun word, ’n unieke vêrveld stralingspatroon skep, wat gesamentlik lei tot ’n hemisferiese gesigsveld. Drie multimodale antenna ontwerpe word voorgestel: ’n dubbelmodale antenna, waarin ’n enkel lineêrgepolariseerde dipool antenna en monopool mede-geleë word, asook twee viermodale antenna ontwerpe waarin twee dubbelgepolariseerde dipool elemente geïntegreer word met medegeleë monopool antenna elemente. Die dubbelmodale antenna word gevoer deur ’n gebalanseerde transmissielyn wat beide differensiële- en gemene-modus seine ondersteun, waar elk onderskeidelik dipool-oor-aardvlak en monopool stralingspatrone voortbring. Die viermodale antennas word elk gevoer deur vier-as transmissielyne wat vier ortogonale transversale elektromagnetiese opwekkingsmodusse ondersteun. Om die multimodale gedrag van die drie multimodale antennas te karakteriseer, word veralgemeende transformasies afgelei waardeur die multimodale strooiingsparameters asook die vêrveld stralingspatrone vanaf enkelpoort strooiingsparameters en vêrvelde bereken word. Hierdie transformasies word toegepas om die gedrag van ’n dubbel- en viermodale antenna ontwerp te karakteriseer deur metings. Ekwivalente netwerkvoorstellings vir aktiewe multimodale antennas word voorgestel, insluitend veralgemeende transformasies om die multimodale sein asook ruis gedrag van die lae-ruis versterkers betreklik te maak tot die tweepoort strooiingsparameters en ruisparameters van die laeruis versterkers. Deur gebruik te maak van klasieke bundelvormingsalgoritmes, word die gedrag van aktiewe dubbelmodale en viermodale antennas voorgestel. Vir die aktiewe dubbelmodale antenna word daar aangedui dat die gesamentlike gebruik van differensiële- en gemene-modus seine, ’n variasie in sensitiwiteit onder 50% tot gevolg het in die E-vlak. Soortgelyk word daar aangedui dat die addisionele opwekkingsmodusse wat deur die aktiewe viermodale antenna ondersteun word, tot ’n beduidende verbetering in die polarisasievermoë oor die gesigsveld lei.

This thesis will explore the function of the conductor’s left hand, with emphasis on its expressive possibilities and the gestures. In the first chapter, the role of the conductor is discussed, and some problems around the field of expressive gestures are brought up. In the second chapter, I present the history of conducting, or rather the history of musical leadership, as the practice of conducting we are familiar with today began in the late 19th Century. In this chapter, I also include some paragraphs about gesture and its role and function outside of musical leadership, such as public speaking. In chapter three, I examine a selection of instruction books and how they treat the use of the left hand. During the work on this material I found several quotations and thoughts from conductors, in letters and interviews, presented in chapter four. This is interesting for this study, because it offers the personal opinions and experiences of well-established conductors and conducting teachers. It also shows how the opinions on the use of the left hand have changed over the past century. Chapter five is a lengthy chapter of research on this topic. Not all is directly connected to the left hand, but all is in connection to gesture in some way. These chapters form the basis of a discussion, where findings in previous chapters are pointed out and debated, and the authors personal opinion is presented. At the end follows suggestions on how this topic can be further researched and how one can create a repertoire of expressive gestures.

Approved for public release; distribution is unlimited / A general study of conductor backed coplanar waveguide is presented. The impedance (Z(0)) and effective dielectric constant (ɛ(reff)) of conductor-backed coplanar waveguide (CBCPW) have been calculated by using a variational method and the boundary point matching method. In this present work only the TEM dominant low frequency propagation mode of coplanar line has been considered. Experimental facilities are vector network analyzer (HP8409) and bench-instrument measurements. / http://archive.org/details/evaluationofcopl00jeon / Captain, Korean Air Force

Eva Jessye (1895-1992) was committed to disseminating music by African Americans through her choral concert performances and choral compositions. This study will examine and interpret Jessye's programming practices as identified in concert programs representing fifty-five years of her professional choral career. The analysis of the tenets of her programming found in printed programs available between the years 1927-1982 will provide a model that can inform choral musicians who plan to program and perform music by African Americans.

Neste trabalho descreve-se a construção de dois equipamentos controladores da temperatura da amostra, que operam entre 77K e 300K e entre 300K e 700K. Apresenta-se os resultados de medidas de T1 e T2, no intervalo de 77K e 700K, realizadas com o campo estático Ho paralelo à direção [111] e uma radiofreqüência de 24MHz. Discutem-se os comportamentos de T1 e T2 neste intervalo de temperaturas e os possíveis mecanismos de relaxação, spin nu clear-rede e spin eletrônico de impureza-rede, atuantes. / In this work we describe the construction of two sample temperature controlled equipments that operate between 77K and 300K and between 300K and 700K. We show the results of T1 and T2 measurements over the temperature range of 77K to 700K with the static field Ho parallel to [111] direction and 24MHz. We discuss the T1 and T2 behavior in this range temperature and the possible relaxation mechanisms of spin nuclear and spin electronic of impurity to lattice that are present.

Thesis advisor: Michael J. Naughton / Quasi-one dimensional (Q1D) molecular organic conductors are among the most exciting materials in condensed matter physics, exhibiting nearly every known ground state. They are highly anisotropic, structurally and electronically, and show large oscillatory phenomena in conductivity for magnetic field rotated in different crystalline planes. Several theoretical works have been published to explain these angular magnetoresistance oscillation (AMRO) effects, but the underlying physics remains illunderstood. Here, we present measurements and calculations of magnetotransport in the molecular organic (super)conductor (DMET)₂I₃ which detect and simulate all known AMRO phenomena for Q1D systems. Employing, for the first time, the true triclinic crystal structure in the calculations, these results address the mystery of the putative vanishing of the primary AMRO phenomenon, the Lebed magic angle effect, for orientations in which it is expected to be strongest. They also show a common origin for Lebed and so-called "Lee-Naughton" oscillations, and confirm the generalized nature of AMRO in Q1D systems. Furthermore, we report the temperature dependence of the upper critical magnetic field in (DMET)₂I₃, for magnetic field applied along the intrachain, interchain, and interplane directions. The upper critical field exhibits orbital saturation at low temperature for field in all directions, implying that superconductivity in (DMET)₂I₃ is conventional spin singlet. / Thesis (PhD) — Boston College, 2010. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Physics.

Neste trabalho foi estudado o condutor protônico HPb2Nb3O10. nH2O , por Ressonância Magnética Nuclear pulsada do próton \'ANTPOT.1H\'. Tanto o estudo da forma de linha como a relaxação spin-rede, em função da temperatura, refletem a mobilidade das espécies protônicas neste material. O início dos movimentos iônicos e moleculares produzem um forte estreitamento da largura de linha acima de 130 K. Os dados da taxa de relaxação spin-rede (1/T1) mostra um máximo entre 253 K e 273 K que depende da hidratação (n). As energias de ativação obtidas dos resultados de relaxação e largura de linha variam entre 0,14eV e 0,4eV, dependendo da hidratação. Os resultados de condutividade e RMN são consistente com um mecanismo de condução do tipo Grotthus, que consiste numa sucessão de movimentos reorientacionais e saltos de prótons. O coeficiente de difusão protônica foi estimado dos parâmetros obtidos de RMN sendo da ordem de 10-8 cm2/s. Este valor leva a uma condutividade da ordem de 10-3 S/ cm. / The protonic conductor HPb2Nb3O10. nH2O , was studied by pulsed Nuclear Magnetic Resonance (NMR) of \'ANTPOT.1H\'. The temperature dependence of the spin-lattice relaxation rate (1/\'T IND.1\') and line width, reflect the mobility of the protonic species present in this material. The onset of ionic and molecular motions produces a strong narrowing of the line at temperatures above 130 K. The spin-lattice relaxation data, obtained above 200 K, shows a maximum in 1/\'T IND.1\', peaking in the range 253 K to 273 K, depending on the value of n. Activation energies of protonic motions, measured from line width and relaxation data, are n dependent and lies in the range of 0,14 eV to 0,4 eV. Results of NMR and conductivity are consistent with the Grotthus conduction mechanism, consisting of a succession of molecular re-orientations and proton jumps. The protonic diffusion coefficient was estimated from the parameters obtained from NMR relaxation and found to be of the order of 10-8 cm2/s, leading to a conductivity of about 10-3 S/ cm.

In the oil and gas industry, statistical methods have been used for corrosion analysis for various asset systems such as pipelines, storage tanks, and so on. However, few industrial standards and guidelines provide comprehensive stepwise procedures for the usage of statistical approaches for corrosion analysis. For example, the UK HSE (2002) report "Guidelines for the use of statistics for analysis of sample inspection of corrosion" demonstrates how statistical methods can be used to evaluate corrosion samples, but the methods explained in the document are very basic and do not consider risk factors such as pressure, temperature, design, external factors and other factors for the analyses. Furthermore, often the industrial practice that uses linear approximation on localised corrosion such as pitting is considered inappropriate as pitting growth is not uniform. The aim of this research is to develop an approach that models the stochastic behaviour of localised corrosion and demonstrate how the influencing factors can be linked to the corrosion analyses, for predicting the remaining useful life of components in oil and gas plants. This research addresses a challenge in industry practice. Non-destructive testing (NDT) and inspection techniques have improved in recent years making more and more data available to asset operators. However, this means that these data need to be processed to extract meaningful information. Increasing computer power has enabled the use of statistics for such data processing. Statistical software such as R and OpenBUGS is available to users to explore new and pragmatic statistical methods (e.g. regression models and stochastic models) and fully use the available data in the field. In this thesis, we carry out extreme value analysis to determine maximum defect depth of an offshore conductor pipe and simulate the defect depth using geometric Brownian motion in Chapter 2. In Chapter 3, we introduce a Weibull density regression that is based on a gamma transformation proportional hazards model to analyse the corrosion data of piping deadlegs. The density regression model takes multiple influencing factors into account; this model can be used to extrapolate the corrosion density of inaccessible deadlegs with data available from other piping systems. In Chapter 4, we demonstrate how the corrosion prediction models in Chapters 2 and 3 could be used to predict the remaining useful life of these components. Chapter 1 sets the background to the techniques used, and Chapter 5 presents concluding remarks based on the application of the techniques.

半導體產業在近二十年來一直在我國經濟發展舞台上扮演積極重要的角色，其績效自然是研究者欲探索之重點。在管理會計頗有作用的作業制成本制度，其提供不同於以往傳統成本制度之資訊，在在替全球知名企業創造更具優勢的管理績效。本研究之重心即在：以深入訪談及田野實證研究方式探討半導體公司導入作業制成本制度後，所發生的績效變化、變化時間與相關資訊，用實證資料檢視作業制成本制度與公司實際經營績效之間的關係，為作業制成本制度在企業之成效作一較為完整且具實務運用的描述，進而提供後續推行作業制成本制度之研究價值，並給予實務界導入作業制成本制度之相關資訊，以作為我國企業推動作業制成本管理制度之參考。 　　本研究以田野實證之資料為主，並以迴歸方式驗證作業制成本資訊釋出前後對企業生產成本與品質之影響，實證結果顯示成本會隨資訊釋出而降低，品質則不會有所變化，表示作業制成本制度確實可以幫助管理者從事成本抑減之工作；也得到品質不會在短期內改善之結論，暗示作業制成本制度之財務績效先於品質績效，資訊使用者之熟練程度差異可能影響績效之出現與否。 　　基於研究所得結論，本研究建議個案公司可以將成本下降之經驗擴散至全廠區，藉由新制度教育員工成本與獲利觀念，並針對員工之使用感想修正個案公司之作業制成本制度。同時也建議未來的研究者，對品質與作業制成本制度甚至成本之關係，作更進一步之研究。 / Using field study method, this study focuses on the relationship between the manufacturing performance of the semi-conductor industry and activity-based costing system information. The analysis suggests that with better decision based on activity and cost driver information, the actvity-based costing information will reduce manufacturing costs while leave quality unchanged. 　　In conclusion, empirical results reveal that manufacturing costs actually decrease with the release of activity-based costing information, while manufacturing quality remains the same. The finding shows that the release of activity-based costing information can reduce the manufacturing costs, but there may not be an immediate effect of quality improvement, suggesting that cost can actually be improved by the activity-based costing system, and quality may need more time and skill toward activity-based costing to change.

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