Asynchronous iterative algorithms are parallel iterative algorithms in which communications and iterations are not synchronized among processors. Thus, as soon as a processing unit finishes its own calculations, it starts the next cycle with the latest data received during a previous cycle, without waiting for any other processing unit to complete its own calculation. These algorithms increase the number of updates in some processors (as compared to the synchronous case) but suppress most idle times. This usually results in a reduction of the (execution) time to achieve convergence. Optimized Schwarz methods (OSM) are domain decomposition methods in which the transmission conditions between subdomains contain operators of the form \linebreak $\partial/\partial \nu +\Lambda$, where $\partial/\partial \nu$ is the outward normal derivative and $\Lambda$ is an optimized local approximation of the global Steklov-Poincar\'e operator. There is more than one family of transmission conditions that can be used for a given partial differential equation (e.g., the $OO0$ and $OO2$ families), each of these families containing a particular approximation of the Steklov-Poincar\'e operator. These transmission conditions have some parameters that are tuned to obtain a fast convergence rate. Optimized Schwarz methods are fast in terms of iteration count and can be implemented asynchronously. In this thesis we analyze the convergence behavior of the synchronous and asynchronous implementation of OSM applied to solve partial differential equations with a shifted Laplacian operator in bounded rectangular domains. We analyze two cases. In the first case we have a shift that can be either positive, negative or zero, a one-way domain decomposition and transmission conditions of the $OO2$ family. In the second case we have Poisson's equation, a domain decomposition with cross-points and $OO0$ transmission conditions. In both cases we reformulate the equations defining the problem into a fixed point iteration that is suitable for our analysis, then derive convergence proofs and analyze how the convergence rate varies with the number of subdomains, the amount of overlap, and the values of the parameters introduced in the transmission conditions. Additionally, we find the optimal values of the parameters and present some numerical experiments for the second case illustrating our theoretical results. To our knowledge this is the first time that a convergence analysis of optimized Schwarz is presented for bounded subdomains with multiple subdomains and arbitrary overlap. The analysis presented in this thesis also applies to problems with more general domains which can be decomposed as a union of rectangles. / Mathematics

ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / The PAM representation was used to formulate a reduced-complexity detector for the Enhanced Flight Termination System (EFTS) whose performance is 5.6 dB better than limiter-discriminator detection when no phase noise is present and 3.4 dB better in the presence of expected phase noise in EFTS.

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

This thesis investigated the final products from the current effluent treatment system for woolscouring (wool washing) plants, namely, (i) sludge produced from the chemical flocculation of solids in the wastewater from the wash bowls, and (ii) concentrated suint (sheep sweat) produced from evaporation of the liquid phase separated from the sludge. In addition, fibrous wastes from the woolscouring process were studied. The aims of the study were to (i) investigate whether suint could be applied in a sustainable way to arable land as a potassium fertiliser, and (ii) assess the conditions under which the sludge could be composted for use as a soil conditioner to return organic matter to soil. Experiments involving suint were performed at both laboratory and glasshouse scales, while experiments involving the solid woolscour wastes were based both in the laboratory and using a small-scale (4.5 m3 total capacity) in-vessel composting unit established at a New Zealand woolscour. Decomposition was measured using net-nitrogen mineralisation and weight loss methods. Suint, the water-soluble contaminants on the fleece, contained high levels of potassium (20% on a dry weight basis) and also appreciable quantities of sulphur, sodium, and chlorine. Biological treatment before evaporation stabilised the resulting suint and improved the consistency of its composition. Suint did not affect the soil processes examined, in that it partly decomposed in soil, did not inhibit the turnover of model organic compounds, did not affect soil properties such as pH and electrical conductivity, and did not lead to increased leaching of mineral nitrogen. Suint was either neutral or positive towards plant performance when applied to soil at a rate of 100 kg potassium per hectare. Suint was therefore judged to be suitable for application to land and could be targeted to soils known to be deficient in potassium or to areas where crops with a high potassium demand are grown. Sludge, composed of dirt (soil particles, faecal matter, and skin and fibre debris) and wool grease, was highly variable in terms of its rate of decomposition, ranging from 0.8 to 27.8% of the initial total nitrogen mineralised over 30 days at 37℃. Fibrous wastes, such as opener (fibre and contaminants removed from the wool by agitation prior to scouring) and scoured wool cleaner (wool fibre and dust removed from scoured and dried wool) wastes, also showed variability in decomposition rates. Sludge decomposition was improved by as much as threefold when co-incubated with fibrous wastes. Although it was shown that the polyacrylamide and pesticide content of sludge did not inhibit its decomposition, the effect of the grease content was not fully understood. Chemical properties of woolscour sludge, such as the carbon to nitrogen ratio, suggested that sludge was a substrate of good resource quality. From a biological perspective, however, the data suggested that woolscour sludge was limited in available nutrients; sludge nitrogen was derived principally from keratin, which decomposed at a low rate resulting in the slow release of mineral nitrogen and low levels of microbial activity. Thus, sludge appeared a poor substrate for composting. However, the results from composting trials indicated that the sludge could be successfully processed after blending with a bulking agent such as sawdust. The blended material showed a 90% reduction in wool grease over 21 days of composting when the moisture content of the composting mass was kept optimal. Compost temperature exceeded 55℃ when wool fibre was added to the blend. Initial results from a case study involving the commercial composting of the entire sludge production (16 tonnes per day) from a New Zealand woolscour indicated that a saleable compost could be produced from a material that would otherwise go to landfill, and served to illustrate the commercial significance of these research results.

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Approved for public release; distribution is unlimited / This thesis estimates the frequency response of a network where the only data is the output obtained from an Autoregressive-moving average (ARMA) model driven by a random input. Models of random processes and existing methods for solving ARMA models are examined. The estimation is performed iteratively by using the Yule-Walker Equations in three different methods for the AR part and the Cholesky factorization for the MA part. The AR parameters are estimated initially, then MA parameters are estimated assuming that the AR parameters have been compensated for. After the estimation of each parameter set, the original time series is filtered via the inverse of the last estimate of the transfer function of an AR model or MA model, allowing better and better estimation of each model's coefficients. The iteration refers to the procedure of removing the MA or AR part from the random process in an alternating fashion allowing the creation of an almost pure AR or MA process, respectively. As the iteration continues the estimates are improving. When the iteration reaches a point where the coefficients converse the last VIA and AR model coefficients are retained as final estimates. / http://archive.org/details/armamodeling00kaya / Lieutenant Junior Grade, Turkish Navy

The upper ocean is host to overlapping vortical and internal waves dynamics over the submesoscales (10-100km), both of which are poorly represented in eddy-resolving ocean models. We analyze upper-ocean (0-200 m) horizontal-wavenumber spectra along Line P in the North Pacific subpolar gyre from shipboard ADCP measurements in February and June (2013-2015), and compare them to spectra from a 1/36th degree numerical simulation output. At scales between 10 and 100 km, the ADCP along-track (Cv) and across-track (Cv) kinetic energy spectra approximately follow power laws of k-2 and have a ratio R = Cv/Cu - 1. For purely non-divergent motions, the order of the power law and R should be the same, so divergent motions are evident. A Helmholtz decomposition estimates the fraction total kinetic energy that is contributed by internal-wave and vortex components. Vortex components follow a power law of k-2 with ratio R-2, consistent with predictions for a non-divergent flow, while internal waves are mostly consistent with the Garrett and Munk internal wave model. There are modest seasonal changes; vortical motions are slightly stronger in February than in June, whereas the amplitudes of the internal wave component increases in June. Depth variability of non-divergent vortical flows shows that at low wave-numbers energy decreases and that the kinetic energy spectra are bluer with depth, inconsistent with predictions from surface quasi-geostrophic theory of redder spectra with depth. Conversely, in the simulation the depth variability of the decomposed vortex components is in agreement with predictions of surface quasi-geostrophic theory. The simulations had very weak internal waves fields. / Graduate / 0415 / manmanw@uvic.ca