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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.
161

Development and evaluation of a non-invasive core temperature measurement system

Cadic, Emily Kathleen 26 July 2012 (has links)
Core body temperature is an important physiological parameter used to identify whether a patient displays a normal, hypothermic, or hyperthermic state. It is routinely monitored during cardiac surgeries and general anesthesia. Currently, the most effective methods for measuring core body temperature are also the most invasive. While select devices have been designed to enable surface recording of internal temperature, none have been implemented in U.S.-based hospitals. The objective of this study was to create a noninvasive core temperature sensor and evaluate its potential of becoming a widely used clinical tool. In tissue phantom and human-based experiments, the prototype performed effectively and posed no safety risk. Provided the prototype can be successfully translated into a more streamlined medical device, it stands to become a staple in operating rooms around the nation. / text
162

Unconditional Relationships within Zero Knowledge

Ong, Shien Jin 09 September 2011 (has links)
Zero-knowledge protocols enable one party, called a prover, to "convince" another party, called a verifier, the validity of a mathematical statement such that the verifier "learns nothing" other than the fact that the proven statement is true. The different ways of formulating the terms "convince" and "learns nothing" gives rise to four classes of languages having zero-knowledge protocols, which are: statistical zero-knowledge proof systems, computational zero-knowledge proof systems, statistical zero-knowledge argument systems, and computational zero-knowledge argument systems. We establish complexity-theoretic characterization of the classes of languages in NP having zero-knowledge argument systems. Using these characterizations, we show that for languages in NP: -- Instance-dependent commitment schemes are necessary and sufficient for zero-knowledge protocols. Instance-dependent commitment schemes for a given language are commitment schemes that can depend on the instance of the language, and where the hiding and binding properties are required to hold only on the YES and NO instances of the language, respectively. -- Computational zero knowledge and computational soundness (a property held by argument systems) are symmetric properties. Namely, we show that the class of languages in NP intersect co-NP having zero-knowledge arguments is closed under complement, and that a language in NP has a statistical zero-knowledge **argument** system if and only if its complement has a **computational** zero-knowledge proof system. -- A method of transforming any zero-knowledge protocol that is secure only against an honest verifier that follows the prescribed protocol into one that is secure against malicious verifiers. In addition, our transformation gives us protocols with desirable properties like having public coins, being black-box simulatable, and having an efficient prover. The novelty of our results above is that they are **unconditional**, meaning that they do not rely on any unproven complexity assumptions such as the existence of one-way functions. Moreover, in establishing our complexity-theoretic characterizations, we give the first construction of statistical zero-knowledge argument systems for NP based on any one-way function.
163

Applications of Many Body Dynamics of Solid State Systems to Quantum Metrology and Computation

Goldstein, Garry 18 March 2013 (has links)
This thesis describes aspects of dynamics of solid state systems which are relevant to quantum metrology and computation. It may be divided into three research directions (parts). For the first part, a new method to enhance precision measurements that makes use of a sensor’s environment to amplify its response to weak external perturbations is described. In this method a “central” spin is used to sense the dynamics of surrounding spins, which are affected by the external perturbations that are being measured. The enhancement in precision is determined by the number of spins that are coupled strongly to the central spin and is resilient to various forms of decoherence. For polarized environments, nearly Heisenberg-limited precision measurements can be achieved. The second part of the thesis focuses on the decoherence of Majorana fermions. Specializing to the experimentally relevant case where each mode interacts with its own bath we present a method to study the effect of external perturbations on these modes. We analyze a generic gapped fermionic environment (bath) interacting via tunneling with individual Majorana modes - components of a qubit. We present examples with both static and dynamic perturbations (noise), and derive a rate of information loss for Majorana memories, that depends on the spectral density of both the noise and the fermionic bath. For the third part of the thesis we discuss vortices in topological superconductors which we model as closed finite systems, each with an odd number of real fermionic modes. We show that even in the presence of many-body interactions, there are always at least two fermionic operators that commute with the Hamiltonian. There is a zero mode corresponding to the total Majorana operator [1] as well as additional linearly independent zero modes, one of which is continuously connected to the Majorana mode in the non-interacting limit. We also show that in the situation where there are two or more well separated vortices their zero modes have non-Abelian Ising statistics under braiding. / Physics
164

Polarizability and Magic-Zero Wavelength Measurements of Alkali Atoms

Holmgren, William Frederick January 2013 (has links)
Atomic polarizability plays an essential role in topics ranging from van der Waals interactions, state lifetimes, and indices of refraction, to next generation atomic clocks and atomic parity non-conservation experiments. Polarizability measurements, such as the ones described in this thesis, provide valuable input to these subjects and serve as benchmark tests for sophisticated atomic structure calculations. We measured the static polarizability of potassium and rubidium with record precision and 0.5% uncertainty using a Mach-Zehnder atom interferometer with an electric-field gradient. To support future precision measurements of polarizability, we developed a new atom beam velocity measurement technique called phase choppers. Using phase choppers, we demonstrated measurements of mean atom beam velocity with an uncertainty of 0.1%. We also developed a new way to probe atomic structure: a measurement of a zero-crossing of the dynamic polarizability of potassium, known as a magic-zero wavelength. We measured the first magic-zero wavelength of potassium with 1.5 pm uncertainty and established a new benchmark measurement for the ratio of the D1 and D2 line strengths. Finally, we propose the use of a resonant photoionization detector for measurements of strontium polarizability, and the use of contrast interferometry for measurements of alkali dimer tensor polarizabilities.
165

Presentation of the Namibia Zero Order Stations and Information Site for Directorate of Survey and Mapping

Haimene, Rachel N. January 2007 (has links)
This project is focused on the presentation of the Namibia Zero Order Stations, including the descriptions of the 21 stations across the country and to create information site for Directorate of Survey and Mapping in Namibia. The main reason for the implementation of web site is for the distribution of information and data to domestic and international clients. Most of the materials and information used in this project were available in digital format. Some information was collected from Directorate of Survey and Mapping of Namibia, Swedesurvey of Sweden, and Asci of Sweden as well as from the internet and library facilities. As such it was very important to analyse and display geo-spatial data before creating web site. The computer makes it possible to create a link between filed documents, maps, graphic documents and other related information using hyperlinking. Therefore the computer made the world easier to communicate and mapping via internet.
166

A New Asset Pricing Model based on the Zero-Beta CAPM: Theory and Evidence

Liu, Wei 03 October 2013 (has links)
This work utilizes zero-beta CAPM to derive an alternative form dubbed the ZCAPM. The ZCAPM posits that asset prices are a function of market risk composed of two components: average market returns and cross-sectional market volatility. Market risk associated with average market returns in the CAPM market model is known as beta risk. We refer to market risk related to cross-sectional market volatility as zeta risk. Using U.S. stock returns from January 1965 to December 2010, out-of-sample cross-sectional asset pricing tests show that the ZCAPM better predicts stock returns than popular three- and four-factor models. These and other empirical tests lead us to conclude that the ZCAPM holds promise as a robust asset pricing model.
167

Sulfate Removal from Reject Brined in Inland Desalination with Zero Liquid Discharge

Almasri, Dema A 16 December 2013 (has links)
Sulfate is one of the most problematic ions present in reject brine in desalination systems due to its high potential of scale formation and membrane fouling; making it an obstacle in the application of zero liquid discharge. The ultra-high lime with aluminum process (UHLA) has shown to effectively remove sulfate. This research involves the study of sulfate removal from the nano-filtration unit in the zero liquid discharge system for inland desalination via a two-stage process using a calcium source to remove sulfate in the first stage and implementing the UHLA process in the second stage. The kinetics, equilibrium characteristics, and effects of different parameters on sulfate removal were studied. Kinetics of sulfate removal was studied on both stages of the process. The observation of fast kinetics in both stages indicated that removal kinetics is not a limitation for the application of the process. Equilibrium characteristics of the UHLA process were performed which revealed efficient sulfate removal at practical ranges of lime and aluminum doses. The effect of pH on sulfate removal in the process was studied. Results showed that sulfate removal in Stage 1 was independent of the pH of the solution while effective sulfate removal in Stage 2 was found to be above a pH of 11. The effect of initial sulfate concentrations on sulfate removal in Stage 1 was investigated and sulfate removal was mainly controlled by calcium sulfate solubility. The effect of initial chloride concentrations on sulfate removal in Stage 2 was evaluated and the results indicated that chloride has negligible effect on the removal of sulfate. Experiments concerning the effect of the recycle of calcium sulfate solids in Stage 1 showed an increase of the reaction rate. In contrast, the recycle of Stage 2 dry solids into Stage 2 revealed no effect on sulfate removal. An equilibrium model was developed to explain the equilibrium characteristics of Stage 2. It was found that a valid explanation for the chemistry of sulfate removal in Stage 2 was the formation of a solid solution consisting of ettringite and monosulfate. XRD analysis confirmed the formation of these solids.
168

Models for Univariate and Multivariate Analysis of Longitudinal and Clustered Data

Luo, Dandan Unknown Date
No description available.
169

Locating the zeros of an analytic function by contour integrals.

Kicok, Eugene. January 1971 (has links)
No description available.
170

The Impact of Neighbourhood Density on the Energy Demand of Passive Houses and on Potential Energy Sources from the Waste Flows and Solar Energy

Stupka, Robert 11 January 2011 (has links)
This study demonstrates how the density of a neighbourhood affects its energy demand, metabolism (energy and material flows) and its ability to produce its own energy. Single-family detached houses and row townhouses were each modeled using passive solar housing guidelines with the DesignBuilder building energy simulation software. Energy demand is then modeled within neighbourhoods at two densities based on south facing windows fully un-shaded at 9:00 am, and 12:00 pm solar time on Dec. 21. The neighbourhood metabolisms were then calculated based on location and density. The potential energy supply was evaluated from the spatial characteristics of the neighbourhood (for solar) and the metabolism (municipal solid waste and wastewater flows.) The potential energy demand and supply are then compared for the varying building types and densities to determine the sensitivity of the energy supply and demand relationships.

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