Tesi sul tema "Wake survey"
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1
Rashid, Dewan Md Harunur Mechanical & Manufacturing Engineering Faculty of Engineering UNSW. "Wake survey behind a rotating ventilator". Awarded by:University of New South Wales. School of Mechanical and Manufacturing Engineering, 2002. http://handle.unsw.edu.au/1959.4/19076.
Testo completoAbstract (sommario):
With environmental concern growing in both affluent and developing countries, roof top ventilators, a form of natural ventilation requiring only wind energy to ensure quality air circulation and comfort is becoming a considered choice of many households and industries. Unfortunately, however, many of these ventilators have evolved through trial and error and the flow physics associated with these ventilators is barely understood. The present experimental project was, therefore, undertaken as part of UNSW- Industry collaboration program funded under an Australian Research Council Grant to explore whether the aerodynamics forces acting on these ventilators during their operation could be obtained. A commercial roof top ventilator supplied by industry was, therefore, tested in an open jet wind tunnel of the University of New South Wales and the results are presented in this thesis. A novel feature of this project is the examination of the suitability of ???the three dimensional wake traverse??? technique to the wake of rotating ventilator. This technique has so far been applied with limited success to the wake of lifting bodies of fixed wing configuration only. In the absence of adequate data in the literature on rotating ventilator, the aerodynamics force components obtained by this technique have been compared against force balance measurements. The results show that the wake traverse technique is capable of determining lift and total drag forces associated with the ventilator flow during its operation from the pressure and velocity information gathered downstream of a ventilator in its wake. Generally, from these data, the technique also allows isolation of the profile and induced components of the drag force. However, from the induced drag value, while it is possible to determine the lift force, it is however, found that a more accurate value of lift force can be evaluated using axial vorticity formulation. The availability of the above technique which does not require measurements on the test specimen itself, will aid in providing a cost efficient investigation of the aerodynamic forces and consequently the performance of a roof top ventilator.
2
Laurent, G. T. "The Bolocam Lockman Hole millimeter-wave galaxy survey". Diss., Connect to online resource, 2006. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3207678.
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3
Ko, Derek M. "The Wage Returns to Same-Sex Parenthood and Their Role in Sexual Orientation Wage Differentials". Scholarship @ Claremont, 2015. http://scholarship.claremont.edu/cmc_theses/1163.
Testo completoAbstract (sommario):
Using data from the 2013 American Community Survey, the author examines the wage returns to same-sex parenthood and their role in the sexual orientation wage gap. Specifically, he compares individuals by gender, sexual orientation, and household earner status. The importance of accounting for household specialization among heterosexual men and women is illustrated by the significant differences in returns to parenthood between heterosexuals of the same gender, but different earner statuses. The empirical results show that gay men face a fatherhood penalty for the presence of children between the ages of 5 and 18 irrespective of earner status. Lesbians on the other hand, experience motherhood premiums for the presence of children under the age of 5, but modest motherhood penalties for the presence of children between the ages of 5 and 18. Ultimately, differences in the wage returns to parenthood for gays, lesbians, and their respective heterosexual counterparts play a negligible role in sexual orientation wage differentials.
4
Teichman, Jason A. "Automated Sea State Classification from Parameterization of Survey Observations and Wave-Generated Displacement Data". ScholarWorks@UNO, 2016. http://scholarworks.uno.edu/td/2199.
Testo completoAbstract (sommario):
Sea state is a subjective quantity whose accuracy depends on an observer’s ability to translate local wind waves into numerical scales. It provides an analytical tool for estimating the impact of the sea on data quality and operational safety. Tasks dependent on the characteristics of local sea surface conditions often require accurate and immediate assessment. An attempt to automate sea state classification using eleven years of ship motion and sea state observation data is made using parametric modeling of distribution-based confidence and tolerance intervals and a probabilistic model using sea state frequencies. Models utilizing distribution intervals are not able to exactly convert ship motion data into various sea states scales with significant accuracy. Model averages compared to sea state tolerances do provide improved statistical accuracy but the results are limited to trend assessment. The probabilistic model provides better prediction potential than interval-based models, but is spatially and temporally dependent.
5
Li, Xiangyang. "Shear-wave splitting in reflection surveys : theory, methods and case studies". Thesis, University of Edinburgh, 1992. http://hdl.handle.net/1842/12418.
Testo completoAbstract (sommario):
Over the last decade, the use of multi-component seismic reflection data to study shear-wave splitting has become increasingly common within the hydrocarbon industry to determine the crack geometry of oil reservoirs. Thus, it is important to investigate the characteristics of, develop processing techniques for, and carry out case studies of shear-wave splitting in reflection surveys. I have examined the effects of anisotropic symmetry, particularly orthorhombic symmetry, on velocity variations and moveouts of split shear-waves in vertical off-symmetry planes. I have also examined the effects of crack orientation changing with depth on reflection and transmission coefficients of split shear-waves. These theoretical developments in understanding shear-wave splitting in reflection surveys are described in Chapters 2 and 3. Complex component analysis was developed as an alternative to polarization analysis for displaying and identifying shear-wave splitting in large seismic datasets. This complex component analysis allows the calculation of instantaneous amplitudes and instantaneous polarizations for two-component seismic data and of shear-wave splitting sections and polarization logs for four-component data. Four field seismic datasets, including a two- and a four-component VSP, a reflection shot data matrix and a two-component crosshole survey, have been used to verify and illustrate the technique, as described in Chapters 4 and 5. A linear-transform technique was developed as an alternative to rotation analysis for quantifying and processing shear-wave splitting in seismic data. This linear-transform technique allows various attributes to be measured, including the polarizations and time delays of split shear-waves and downhole geophone orientation. It also allows time series of the split shear-waves to be separated deterministically and such separation can be made before stacking in reflection surveys. Three field datasets including a zero-offset VSP, an offset VSP and a reflection shot data matrix, have been used to verify and illustrate the technique, as described in Chapter 6.
6
McCorkle, Tricia Dawn. "Math, music, and membranes: A historical survey of the question "can one hear the shape of a drum"?" CSUSB ScholarWorks, 2005. https://scholarworks.lib.csusb.edu/etd-project/2933.
Testo completoAbstract (sommario):
In 1966 Mark Kac posed an interesting question regarding vibrating membranes and the sounds they make. His article entitled "Can One Hear the Shape of a Drum?", which appeared in The American Mathematical Monthly, generated much interest and scholarly debate. The evolution of Kac's intriguing question will be the subject of this project.
7
ZHAO, Ling. "Wage Discrimination and the Hukou System in China: Survey-based Analyses for Manufacturing Workers in Pearl River Delta". 名古屋大学大学院国際開発研究科, 2012. http://hdl.handle.net/2237/16251.
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8
Hartman, Adam. "Roman Fine Ware Ceramics from Two Surface Scatters in Aegean Thrace: An Analysis of Distribution Patterns". University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1613683832182765.
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9
Faulkner, R. F. J. "Seto and Mino kiln sites : An archaeological survey of the Japanese medieval glazed ware tradition and its early modern tradition". Thesis, University of Oxford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.381812.
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Yoon, Seok Hee. "Relations between Japan and Korea : a diachronic survey in search of a pattern". Thesis, University of Canterbury. Japanese, 2015. http://hdl.handle.net/10092/10393.
Testo completoAbstract (sommario):
Ever since Korea and Japan established kingdoms in the 6th century, both countries greatly influenced each other politically, militarily, socially, culturally, and economically through international exchange. Korea and Japan kept their close relationship throughout history because of geographic proximity. It is also notable that 54 per cent of Japanese males and 66 per cent of Japanese females carry Sino-Korean genes in present-days and there are records that Japan carried a close relationship with Paekche, a kingdom of the Korean peninsula which introduced script, Confucianism, and Buddhism to Japan at an early stage.
In the Medieval Period, Korea and Japan maintained a friendly trade policy but there were incidents such as Mongol invasions, wakō (Japanese pirates) raids and two invasions by Toyotomi Hideyoshi, which worsened the relations between the two countries. And yet, during Japan’s period of isolation (from 1639 to1854), Korea was the only nation with which full and free trade was permitted.
The 20th century is based on invasion and colonisation of Japan over Korea. For 35 years from 1910 to 1945, under the control of Japan, the Japan-Korea relationship was nothing but misfortune: forced labour, suppression of Korean culture and language, press-gangs, sex slaves, and so forth.
The aim in this thesis is to go into greater detail about each significant event and its effect on the relationship between Japan and Korea to uncover some rationale or pattern such as gekokujō (the master being outdone by the pupil, and being treated thereafter with contempt).
11
Chaiprakaikeow, Susit. "New Methods for Engineering Site Characterization Using Reflection and Surface wave Seismic Surveys". DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1273.
Testo completoAbstract (sommario):
This study presents two new seismic testing methods for engineering application, a new shallow seismic reflection method and Time Filtered Analysis of Surface Waves (TFASW). Both methods are described in this dissertation. The new shallow seismic reflection was developed to measure reflection at a single point using two to four receivers, assuming homogeneous, horizontal layering. It uses one or more shakers driven by a swept sine function as a source, and the cross-correlation technique to identify wave arrivals. The phase difference between the source forcing function and the ground motion due to the dynamic response of the shaker-ground interface was corrected by using a reference geophone. Attenuated high frequency energy was also recovered using the whitening in frequency domain. The new shallow seismic reflection testing was performed at the crest of Porcupine Dam in Paradise, Utah. The testing used two horizontal Vibroseis sources and four receivers for spacings between 6 and 300 ft. Unfortunately, the results showed no clear evidence of the reflectors despite correction of the magnitude and phase of the signals. However, an improvement in the shape of the cross-correlations was noticed after the corrections. The results showed distinct primary lobes in the corrected cross-correlated signals up to 150 ft offset. More consistent maximum peaks were observed in the corrected waveforms. TFASW is a new surface (Rayleigh) wave method to determine the shear wave velocity profile at a site. It is a time domain method as opposed to the Spectral Analysis of Surface Waves (SASW) method, which is a frequency domain method. This method uses digital filtering to optimize bandwidth used to determine the dispersion curve. Results from testings at three different sites in Utah indicated good agreement with the dispersion curves measured using both TFASW and SASW methods. The advantage of TFASW method is that the dispersion curves had less scatter at long wavelengths as a result from wider bandwidth used in those tests.
12
Borstad, Eriksen Martin. "Cross-correlating spectroscopic and photometric galaxy surveys". Doctoral thesis, Universitat Autònoma de Barcelona, 2014. http://hdl.handle.net/10803/133261.
Testo completoAbstract (sommario):
En esta tesis se estudia el acotamiento en los paraámetros cosmología al
combinar observaciones en catálogos de galaxias espectroscópicas y
fotométricos. Los catálogos fotométricos miden las distorsiones de lente
gravitacional débil (WL), mientras que los catalogos espectroscópicos, con más
alta precisión en la información de redshift (o corriento al rojo), son ideales
para el estudio de distorsiones espaciales de redshift (RSD). El análisis
combinado se realiza únicamente com funciones de correlación angular, lo que
simplifica el estudio, en particular en lo que respecta a la inclusión de la
covarianza entre observables.
El primer capítulo presenta un nuevo algoritmo para el cálculo eficaz de las
correlaciones cruzadas de varios marcadores, incluidos WL en correlaciones
cruzadas con bines estrechos. Estimar la función de correlación angular es
particularmente costoso dado que el número de correlaciones cruzadas aumenta
como O(n^2), donde $n$ es el número de bines en redshift.
Más adelante, el capítulo estudia el efecto de aproximación de Limber, y RSD en
el modelado de correlaciones auto y cruzadas. Para bines de redshift delgados,
la aproximación de Limber deja de funcionar y no permite incorporar las
correlaciones cruzadas. Al disminuir el ancho de los bines en redshift, crece
la amplitude de correlacion y el efecto de RSD, lo que redundará en beneficio
del acotamiento de parametros cosmológicos. Una tendencia interesante es la
contribución de las oscilaciones acústicas de bariones (BAO) en la correlacion
cruzadas entre bines de distitnto redshift. La separacion en redshift entre dos
bines reduce la amplitud de las correlaciones en escalas pequeñas, lo que
aumenta el contraste en el BAO. También estudiamos la relación señal-ruido de
diferentes correlaciones cruzadas.
El segundo Capítulo presenta un pronóstico de cotas en la historia de la
expansión y del crecimiento cósmico, usando un catalogo spectroscópico y otro
fotométrico ficticios de 14000 grados cuadrados cada uno. Cuando estos
catalogos se sobrelapan en la misma region del cielo, encontramos mejores cotas
en los parametros cosmológicos. Esto es debido a las correlaciones cruzadas
adicionales entre catálogos y la reducción de la varianza en el muestreo
(debida a la covarianza entre trazadores). En primer lugar mostramos un estudio
por separado de la dependencia en el ancho de bin en redshift, en RSD, en BAO y
en WL. Encontramos ganancias equivalentes a tener el 30% mas de área en los
catalogos cuando estos se superponen en el cielo. Por último, analizamos el
origen de esta moderada ganancia en el contexto de la literatura existente.
Diferentes grupos han reportado que al solapar los catalogos o bien no
encuentran ningún beneficio o bien encuentran grandes beneficios. Nosotros
sugerimos que la covarianza entre observables y el uso de diferentes
observables puede explicar estas diferencias.
El sesgo (bias) en galaxias, relaciona las sobredensidades de galaxias con las
del campo de fluctuaciones de materia, de manera que la incertidumbre en el
bias limita las predicciones. Por ello investigamos con detalle como las
correlaciones cruzadas, RSD, BAO y WL afectan las medidas del bias en galaxias.
En particular, cuando los catalogos sobrelapan disminuyen los errores en el
bias para la muestras fotométrica. La última seccion cuantifica los
beneficios de los "priors'' y los efectos de la estocasticidad en el bias. El
impacto de las incertidumbres en las estocasticidad es menor cuando hay
sobrelapamiento.In this thesis we study constraining cosmology when combining spectroscopic and photometric galaxy survey. The photometric survey measures galaxy shape distortions from Weak Lensing (WL), while high precision redshift information makes spectroscopic surveys ideal for redshift space distortions (RSD). The combined analysis is performed entirely in angular-correlation functions, which simplifies the joined analysis, in particular the inclusion of covariance between then. The first chapter introduce a novel algorithm for efficiently calculating the cross-correlations of multiple tracers (i.e. galaxy types/luminosities) and including WL in narrow redshift bin cross-correlations. Estimating the angular-correlations function is in particular demanding since the number for cross-correlations increase O(n^2) with $n$ being the number of redshift bins. Later the chapter study the effect of Limber approximation and RSD on the modeling of auto- and cross-correlations. For thin redshift bins, the Limber approximation completely breaks down and does not allow cross-correlations between redshift bins. Decreasing the bin width increases the amplitude of the galaxy correlations and the effect of RSD, which will benefit the cosmological constraints. One interesting trend is the baryon acoustic oscillation (BAO) contribution in the cross-correlations of redshift bins. The redshift separations between two bins reduce small-scale clustering, hence increasing the BAO contrast. We also study the signal-to-noise of different cross-correlations. The second chapter forecast the constraints on the cosmic expansion and growth history, using two fiducial 14000 sq deg. spectroscopic and photometric galaxy surveys. Overlapping surveys (same sky) has improved constraints from additional cross-correlations and sample variance cancellations (covariance in multiple tracers). We study first separate how redshift bin width, RSD, BAO and WL affect the forecast. We find gains equivalent to 30\% larger areas when using overlapping surveys. Last, we discuss the origen of this moderate gain in the context of existing literature. Different groups reports either none or high benefits for overlapping galaxy surveys. We suggest the covariance between surveys and different same-sky definitions (i.e. different observables) can explain the differences. Galaxy bias relate the galaxy overdensities to the underlying matter fluctuations, and the uncertainty in galaxy bias strongly affects the forecast. We therefore investigate in detail how cross-correlations, RSD, BAO and WL affects constraints on galaxy bias. Overlapping surveys in particular increase constraint on the bias from the photometric sample. Last section quantify the benefit of priors and the effect of bias stochasticity. The impact of uncertainties in bias stochasticity is less for overlapping surveys.
13
Naylor, Bret J. Zmuidzinas Jonas Zmuidzinas Jonas. "Broadband millimeter-wave spectroscopy with Z-Spec : an unbiased molecular-line survey of the starburst galaxy M82 /". Diss., Pasadena, Calif. : California Institute of Technology, 2008. http://resolver.caltech.edu/CaltechETD:etd-05282008-104041.
Testo completo
14
Cowperthwaite, P. S., E. Berger, M. Soares-Santos, J. Annis, D. Brout, D. A. Brown, E. Buckley-Geer et al. "A DECAM SEARCH FOR AN OPTICAL COUNTERPART TO THE LIGO GRAVITATIONAL-WAVE EVENT GW151226". IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/621399.
Testo completoAbstract (sommario):
We report the results of a Dark Energy Camera optical follow-up of the gravitational-wave (GW) event GW151226, discovered by the Advanced Laser Interferometer Gravitational-wave Observatory detectors. Our observations cover 28.8 deg(2) of the localization region in the i and z bands (containing 3% of the BAYESTAR localization probability), starting 10 hr after the event was announced and spanning four epochs at 2-24 days after the GW detection. We achieve 5 sigma point-source limiting magnitudes of i approximate to 21.7 and z approximate to 21.5, with a scatter of 0.4 mag, in our difference images. Given the two-day delay, we search this area for a rapidly declining optical counterpart with greater than or similar to 3 sigma significance steady decline between the first and final observations. We recover four sources that pass our selection criteria, of which three are cataloged active galactic nuclei. The fourth source is offset by 5.8 arcsec from the center of a galaxy at a distance of 187 Mpc, exhibits a rapid decline by 0.5 mag over 4 days, and has a red color of i - z approximate to 0.3 mag. These properties could satisfy a set of cuts designed to identify kilonovae. However, this source was detected several times, starting 94 days prior to GW151226, in the Pan-STARRS Survey for Transients (dubbed as PS15cdi) and is therefore unrelated to the GW event. Given its long-term behavior, PS15cdi is likely a Type IIP supernova that transitioned out of its plateau phase during our observations, mimicking a kilonova-like behavior. We comment on the implications of this detection for contamination in future optical follow-up observations.
15
Carpi, Isotta. "Seismic Metamaterials for Rayleigh waves attenuation: analytical and numerical survey on the effect of soil stratification". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016.
Cerca il testo completoAbstract (sommario):
Locally resonant materials and periodic media have been recently proposed as a mean to control and redirect elastic waves at different length scale.
In particular, at geophysical scale, large resonant/periodic structures have been used as an innovative solution to attenuate the propagation of seismic waves.
Previous studies have shown the possibility of attenuating surface ground motions by deflecting seismic Rayleigh waves into soil bulk.
This surface to bulk wave conversion has been proved in the case of homogenous soil. Here we investigate how the surface to bulk wave conversion is influenced by inhomogeneous depth dependent soil properties.
Analytical and numerical evaluation have been developed in time and frequency domain to determine the efficiency of soil-resonators interaction in inhomogeneous layered media to be used as comparison with experimental results obtained from an experimental setup built at ETH. Furthermore, results from the inhomogeneous case have been compared with the homogenous soil case, to exploit effectiveness and limitation of wave conversion phenomenon.
It has been shown that the soil with depth dependent profile strongly influence wave motion. In fact, no effective wave conversion is present in this case, due to stiffer properties of the soil with depth that force the wave to reconvert its direction to the surface.
16
Tang, XiaoNan. "Derivation of the wave speed-discharge relationship from cross section survey for use in approximate flood routing methods". Thesis, University of Birmingham, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.692832.
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Skilling, Hayden. "Maternity Risk and the Lesbian Pay Gap: Evidence from the U.S. Decennial Census and American Community Survey". Thesis, University of Canterbury. Department of Economics and Finance, 2014. http://hdl.handle.net/10092/9243.
Testo completoAbstract (sommario):
Prior research from the U.S. and abroad reveals a sizable lesbian earnings advantage over otherwise-similar heterosexual women. Using data from the 2000 U.S. Census and 2005-2010 American Community Surveys, we estimate traditional earnings equations and find robust evidence of a lesbian premium, corroborating the findings of previous studies. Using within-sample maternity incidence as an estimate of employers' forward-looking expectations, we then examine whether differences in the perceived likelihood of an employee requiring maternity leave, here-labelled 'maternity risk', contribute to the lesbian pay gap. Results from a direct assessment suggest that maternity risk adversely affects income, and that accounting for near-term differences in maternity risk reduces the lesbian premium by approximately ten to fifteen percent. Further analyses, using proxy variables for differential maternity risk, yield similar results. As such, the persistent finding of a lesbian earnings advantage in previous studies can be attributed, at least in part, to employers' aversion to maternity risk and its associated costs.
These findings are also of critical importance to the general labour-market discrimination literature. Given the adverse earnings effect of maternity risk, our analysis suggests that estimates of the well-established gender earnings disparity are likely to be considerably smaller when incorporating maternity risk into the analysis. Absent the ability to adequately control for maternity risk, strict attention should be paid to potential upward bias in estimated earnings differentials. Moreover, policymakers should consider the broader implications of maternity-leave policy on the labour-market outcomes of females. In this respect, maternity-leave policy may influence the hiring and promotion decisions of employers, thereby indirectly affecting sexual-orientation and gender equality in the labour market. However, further research in this area is still required, given the limitations inherent in the direct and indirect analyses.
18
Frink, William D. Jr. "Hot-wire surveys in the vortex wake downstream of a three-percent fighter aircraft model at high angles of attack". Thesis, Monterey, California: Naval Postgraduate School, 1990. http://hdl.handle.net/10945/27586.
Testo completoAbstract (sommario):
Approved for public release; distribution is unlimited.A low-speed wind tunnel investigation was conducted to examine the vortex wake downstream of a three-percent scale model of the YF-17 lightweight fighter prototype at high angles of attack. The study was in support of NASA ames Research Center's wind tunnel investigation of a full scale FA-18 as part of NASA's High Alpha Technology Program. Smoke flow visualization was used to locate the downstream vortex wake. Hot-wire surveys were taken through the vortex at two stations; one directly aft of the model and the other at a station three model lengths downstream of the model. The effect of adding a fence to the leading edge extension (LEX) was studied. Power spectra from the hot-wire were recorded for the survey station directly aft of the model. Results show that: peak turbulent fluctuation at this station occurred at 25 deg angle of attack; lateral turbulent fluctuation greatly diminished at the far downstream station; and the addition of the LEX fence shifted energy content of turbulence toward higher frequencies.
19
Frink, William D. "Hot-wire surveys in the vortex wake downstream of a three-percent fighter aircraft model at high angles of attack". Monterey, California : Naval Postgraduate School, 1990. http://handle.dtic.mil/100.2/ADA241869.
Testo completoAbstract (sommario):
Thesis (M.S. in Engineering Science)--Naval Postgraduate School, December 1990.Thesis Advisor(s): Hebbar, Sheshagiri K. ; Platzer, Max F. "December 1990." Description based on title screen as viewed on March 31, 2010. DTIC Identifier(s): Trailling Vortices, Wake, Trubulent Flow, Jet Fighters, High Alpha (High Angle of Attack), Vortex Wake, Angle of Attack, Extendable Structures, Leading Edges, Fences, Lex Fences, Wind Tunnel Models, F-17 Aircraft, F/A-18 Aircraft, Wind Tunnel Tests, Hot Wire Anemometers, Theses. Author(s) subject terms: High Angle-of-Attack Aerodynamics, Hot-Wire Measurements, Wind Tunnel Studies. Includes bibliographical references (p. 24-25). Also available in print.
20
Cheng, Pak-ho, e 鄭柏濠. "P wave characteristics and QRS duration in patients after Fontan-type procedures". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B43781627.
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Abulgasem, Elmabruk. "A haptic surgical simulator for cataract eye surgery using circular wave model". Thesis, University of Salford, 2010. http://usir.salford.ac.uk/26496/.
Testo completoAbstract (sommario):
Standard surgical training consists of the acquisition of theoretical knowledge complemented with practical observation during surgery and, at some advanced stage, performing the surgical procedures on live patients under the supervision of qualified surgeon. Also, experienced surgeons still require training to perform rare and complex cases. However, a potentially contradictory situation exists whereby patients' expectations of surgical experience are obviously high, whereas clinical governance requires surgeons' track records to be established before they move to operate on live patients. There is increasing fear of litigation among healthcare professionals, along with worktime legislation which limits the hours available for training. Therefore there is a need for surgical simulation systems for training to overcome the initial lack of experience and for planning of rare and complex procedures. In this thesis we have developed a Cataract Eye Surgery Simulation system (CESS) with the capability to simulate, in addition to the basic surgical interaction, the main steps of cataract eye surgery, and which can be used as a teaching and training method to train medical students in a realistic environment. The CESS, in its present form, provides users with an interactive, affordable, easy to learn, risk-free, reusable and adaptable means for training in cataract eye surgery procedures. In this thesis we have presented and examined different modelling techniques that have been used for soft tissue simulations. In particular, we have been interested in the computation complexity of the models, numerical stability, and physical realism. Within this context, we proposed the Circular Wave Model (CWM) which is capable of modelling homogeneous, surface objects and is fast enough for applications such as surgery simulations. The CWM algorithm is derived using the analogy of water waves produced when water is hitby stone. Two dimensional (2D) and three dimensional (3D) objects can interactively be deformed with the CWM. We have put forward a new technique to assign stiffness and damping coefficients to springs of the mesh being manipulated and the spring that connects the virtual surgical instrument to its manipulated mesh.
22
Soares-Santos, M., R. Kessler, E. Berger, J. Annis, D. Brout, E. Buckley-Geer, H. Chen et al. "A DARK ENERGY CAMERA SEARCH FOR AN OPTICAL COUNTERPART TO THE FIRST ADVANCED LIGO GRAVITATIONAL WAVE EVENT GW150914". IOP PUBLISHING LTD, 2016. http://hdl.handle.net/10150/621228.
Testo completoAbstract (sommario):
We report the results of a deep search for an optical counterpart to the gravitational wave (GW) event GW150914, the first trigger from the Advanced LIGO GW detectors. We used the Dark Energy Camera (DECam) to image a 102 deg(2) area, corresponding to 38% of the initial trigger high-probability sky region and to 11% of the revised high-probability region. We observed in the i and z bands at 4-5, 7, and 24 days after the trigger. The median 5 sigma point-source limiting magnitudes of our search images are i = 22.5 and z = 21.8 mag. We processed the images through a difference-imaging pipeline using templates from pre-existing Dark Energy Survey data and publicly available DECam data. Due to missing template observations and other losses, our effective search area subtends 40 deg(2), corresponding to a 12% total probability in the initial map and 3% in the final map. In this area, we search for objects that decline significantly between days 4-5 and day 7, and are undetectable by day 24, finding none to typical magnitude limits of i = 21.5, 21.1, 20.1 for object colors (i - z) = 1, 0, - 1, respectively. Our search demonstrates the feasibility of a dedicated search program with DECam and bodes well for future research in this emerging field.
23
Choi, Youngsuk. "Human capital investments and interregional wage differences in a Southeast Asian country : evidence from 1993 Indonesian Family Life Survey (IFLS) data /". Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/7402.
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Rosandich, Brooks. "Extension of a Quaternary-Active Shear Zone across the Reelfoot Fault Stepover Arm: Evidence from P- and SH-wave Seismic Reflection Imaging". UKnowledge, 2019. https://uknowledge.uky.edu/ees_etds/79.
Testo completoAbstract (sommario):
Many seismic hazard source parameters such as slip rate, total displacement, strain accommodation, geographic fault location, etc. are poorly constrained in the New Madrid seismic zone (NMSZ). This is in large part due to the masking effect of the thick Mississippi embayment sediment package on seismogenic structures and features. Consequently, much of the subsurface geologic characterization needed for understanding seismic hazard sources requires geophysical imaging. Recent seismic reflection surveys 12 km NE of the Reelfoot Fault stepover arm of the NMSZ have suggested a northeast-oriented transpressional fault zone extending across the Reelfoot Fault stepover arm where its dextral displacement at seismogenic depth is unbalanced with the surface expression, the Reelfoot Scarp. New high-resolution seismic reflection surveys were acquired across the southwestern back projection of the hypothesized structure at a potential piercing point with the Reelfoot Fault near Proctor City, TN. The resultant images show steeply dipping northeast striking faults with uplifted and arched post-Paleozoic reflectors that extend into the Quaternary sediments, consistent with the findings of the previous surveys. The new imaged faults form a ~500-meter-wide positive flower structure, with vertical displacements of 16 m and 50 m at the top of the Eocene and top of the Paleozoic reflectors, respectively. Results corroborate the Axial Fault extending to the northeast, and provide geological evidence for Reelfoot Fault segmentation. Furthermore, the near-surface SH-wave seismic profiles show the through-going shear deformation has continued into the Quaternary, thus indicating seismogenic strain has not been completely transferred to the Reelfoot Fault, providing additional evidence for accommodating the strain imbalance.
25
Sowa, Victor. "Men and Women’s Return to Cognitive Skills. : Evidence from PIAAC". Thesis, Uppsala universitet, Nationalekonomiska institutionen, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-227789.
Testo completoAbstract (sommario):
Do men and women receive different pay-offs, in terms of wage, from cognitive skills in the Swedish labor market? To answer this, the classical Mincer equation is expanded with a variable for cognitive skills (literacy and numeracy) and an interaction term between being a male and cognitive skills to be able to distinguish the actual difference in pay-off. I use data from OECD’s PIAAC survey of adult skills, which provides a unique opportunity to examine gender pay-off differences concerning cognitive skills. The results show that men have a larger pay-off than women once occupation is sufficiently controlled for
26
Dieckmann, Mark Eric. "A survey of elementary plasma instabilities and ECH wave noise properties relevant to plasma sounding by means of particle in cell simulations". Thesis, University of Warwick, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327557.
Testo completo
27
Bhorat, Haroon. "Employment, earnings and vulnerability in the South African labour market : an empirical investigation based on official survey data". Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53405.
Testo completoAbstract (sommario):
Thesis (PhD)--Stellenbosch University, 2003.ENGLISH ABSTRACT: The welfare challenge that faces South Africa in the post-apartheid period is, at its core, defined by the high levels of poverty and inequality in the society. The labour market, as a provider of wages to individuals and ultimately households, remains the key transmitter of these poverty and inequality outcomes in the society. This specific line of reasoning is the underlying intellectual thrust of this thesis: namely that the state of poverty and inequality in a society is mirrored by, and perhaps more strongly - determined and shaped - by the state of its labour market. The thesis therefore focuses in the first instance on employment trends in South Africa since 1970, across two discrete time periods. The intention is to sketch the changing patterns of labour demand in South Africa, with a particular focus on how these patterns have yielded differential gains for different occupation, race, gender and education cohorts. Ultimately, these uneven employment patterns remain one of the most significant factors shaping South Africa's poverty and inequality challenges. The inequality challenge, so often thought of in terms of households only, is analysed here purely in terms of the employed. The starting point once again, is that it is precisely these earnings that contribute to the extraordinarily high inequality levels in South Africa. This analysis imparts information about the manner in which intra-employed wage inequality is structured and furthermore, how South Africa compares in the international context. A major contribution of the thesis is to, through more formal measures of poverty, apply these to labour market-defined individuals, rather than households, which is the norm in the literature. The point of departure is of course that poverty, or vulnerability, expresses itself through individuals in the labour market, and is thereby transmitted at the household level. Hence a significant component of the dissertation attempts a formal measurement and modelling of the degree of poverty and vulnerability in the South African labour market. These welfare challenges for a society though, should not only be analysed, but rather solved as well. Hence the final two chapters of the dissertation attempts to examine two very recent policy options mooted in South Africa, and through using simulation techniques, attempts to estimate both the costs and benefits of instituting these two alternatives which are explicitly aimed at reducing poverty, vulnerability and inequality in the society.
AFRIKAANSE OPSOMMING: Suid-Afrika se welvaartsvraagstuk in die na-apartheidsperiode word deur die hoë vlakke van armoede en ongelykheid in die samelewing bepaal. Die arbeidsmark, as voorsiener van lone aan individue en uiteindelik ook huishoudings, is die belangrikste bepaler van die oordrag van armoede- en ongelykheidsuitkomste in die samelewing. Die sleuteluitgangspunt van hierdie proefskrif is dat die stand van armoede en ongelykheid in 'n samelewing in sy arbeidsmark weerspieël en selfs daardeur bepaal en gevorm word. Die proefskrif fokus daarom veralop Suid- Afrikaanse indiensnemingstendense sedert die sewentigerjare, in twee diskrete periodes. Die doel is om die veranderende Suid-Afrikaanse arbeidsvraagpatroon te skets, veral die ongelyke voordele wat hierdie patrone vir verskillende beroeps-, rasse-, gestags- en opvoedkundige groepe meegebring het. Hierdie ongelyke indiensnemingspatrone is uiteindelik belangrike determinante van Suid-Afrika se armoede- en ongelykheidsvraagstuk. Hierdie analise verskaf inligting omtrent die struktuur van loonongelykheid onder werkendes en hoe Suid-Afrika internasionaal vergelyk. 'n Belangrike bydrae is die toepassing van formele armoedemaatstawwe op individue in die arbeidsmark, eerder as die konvensionele toepassing op huishoudings. Die uitgangspunt is natuurlik dat armoede of weerloosheid in die arbeidsmark op die vlak van die individu ervaar word, en dat dit daarna na die huishouding oorgedra word. Daarom is 'n groot deel van die proefskrif op die formele meting en modellering van die omvangvan armoede en weerloosheid in die Suid-Afrikaanse arbeidsmark toegespits. Hierdie welsynsvraagstukke moet natuurlik nie net ontleed word nie, maar ook opgelos word. Daarom poog die laaste twee hoofstukke om die implikasies van twee onlangse beleidsvoorstelle te ontleed. Deur simulasietegnieke word probeer om die kostes en voordele van hierdie twee alternatiewe beleidsvoorstelle gemik op die vermindering van armoede, ongelykheid en weerloosheid in die samelewing te beraam.
28
Streng, Catherine Ann. "Riding the Wave: How the Media Shapes South Korean Concepts of Beauty". Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1157645/.
Testo completoAbstract (sommario):
This thesis features a qualitative analysis of eight Korean media products — both fiction and nonfiction. For many years, South Korea (hereafter also called Korea) has been called the "world's plastic surgery capital" by many publications, such as Business Insider and The New Yorker. Although Business Insider considers the United States the "vainest country in the world," the numbers of cosmetic surgeries, percentage wise, per person in Korea still outnumber those in the United States, with 20 procedures per 1,000 persons. In this thesis, I argue by using the cultivation theory that Korean television, such as K-Dramas, talk shows and films, which celebrate transformations and feature makeovers and thus normalize cosmetic surgery, create a fantastic space for viewers where the viewers are compelled to act on a media-generated desire to undergo cosmetic surgery in the belief that doing so will also transform or better their lives in the same way it does for the characters in these Korean television productions.
29
Mishra, Vijay. "Impact of Hurricanes on Structures - A Performance Based Engineering View". Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3251.
Testo completoAbstract (sommario):
The magnitude of damage caused to the United States (US) coast due to hurricanes has increased significantly in the last decade. During the period 2004-2005, the US experienced seven of the costliest hurricanes in the country's history (NWS TPC-5, 2007) leading to an estimated loss of ~ $158 billion. The present method for predicting hurricane losses, HAZUS (HAZard US), is solely based on hurricane hazard and damage caused to building envelopes only and not to structural systems (Vickery et al., 2006). This method does not take into account an intermediate step that allows for better damage estimates, which is structural response to the hazards that in turn can be mapped to the damage. The focus of this study was to quantify the uncertainty in response of structures to the hurricane hazards associated with hurricanes from performance based engineering perspective. The study enumerates hazards associated with hurricanes events. The hazards considered can be quantified using a variety of measures, such as wind speed intensities, wave and surge heights. These hazards are quantified in terms of structural loads and are then applied to a structural system. Following that, structural analysis was performed to estimate the response from the structural system for given loads. All the possible responses are measured and they are fitted with suitable probability distribution to estimate the probability of a response. The response measured then can be used to understand the performance of a given structure under the various hurricane loads. Dynamic vs. static analysis was performed and results were compared. This will answer a few questions like, if there is any need to do both static and dynamic analysis and how hurricane loads affect the structural material models. This being an exploratory study, available resources, research, and models were used. For generation of annual or extreme values of hazard, various available wind speed, storm surge, and wave height models were studied and evaluated. The wind field model by Batts et al. (1980) was selected for generation of annual wind speed data. For calculation of maximum storm surge height, the Sea, Lake Overland Surges from Hurricane (SLOSH, Jelesnianski et al., 1992) program was used. Wave data was acquired from a National Oceanic and Atmospheric Administration (NOAA) database. The (extreme or annual) wind speed, surge height, and wave height generated were then fitted by suitable probability distributions to find the realizations of hazards and their probabilities. The distribution properties were calculated, correlations between the data were established, and a joint probability distribution function (PDF) of the parameters (wind speed, wave height, and storm surge) was generated. Once the joint distribution of extreme loads was established, the next step was to measure the dynamic response of the structural system to these hazards. To measure the structural response, a finite element model of three-story concrete frame were constructed. Time histories of wind load were generated from wind net pressure coefficients recorded in a wind tunnel test (Main and Fritz, 2006). Wave load time histories were generated using laboratory basin test (Hawke's et al., 1993) wave height time history data and were converted into wave loads using Bernoulli's equation. Surge height was treated as a hydrostatic load in this analysis. These load time histories were then applied to the finite element model and response was measured. Response of the structural system was measured in terms of the mean and maximum displacements recorded at specific nodes of model. Response was calculated for loads having constant mean wind speed and surge/wave and different time histories. The dominant frequency in the wind load time histories was closer to the natural frequency of the structural model used than the dominant frequency in the wave height time histories. Trends in the response for various combinations of mean wind speed, wave height, and surge heights were analyzed. It was observed that responses are amplified with increase in the mean wind speed. Less response was measured for change in mean surge/wave height as the tributary area for wave forces was less compared to wind force. No increase in dynamic amplification factor was observed for increase in force time histories case.M.S.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil Engineering MS
30
Mahvelati, Shams Abadi Siavash. "Advancements in Surface Wave Testing: Numerical, Laboratory, and Field Investigations Regarding the Effects of Input Source and Survey Parameters on Rayleigh and Love waves". Diss., Temple University Libraries, 2019. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/589154.
Testo completoAbstract (sommario):
Civil EngineeringPh.D.
The Multichannel Analysis of Surface Waves (MASW) method has been widely used to evaluate the subsurface in engineering applications since late 1990’s. In MASW, surface waves are introduced into the subsurface and recorded by sensors along the ground surface. The characteristics of the propagating surface wave are influenced by the subsurface stratification, the manner in which the surface waves are input into the ground, and the survey parameters to acquire data. Rayleigh waves are typically generated by vertical strikes on a metallic plate which serves as a coupler between the active input source (e.g., a sledgehammer) and the ground surface. It has been suggested that plastic-type base plates can improve the low-frequency energy of Rayleigh waves and therefore, can increase the depth of investigation among other potential improvements. However, very little studies exist in the literature that evaluate the role of base plate material, especially plastic materials. In addition to Rayleigh surface waves, seismic surface waves can also be generated with horizontal impacts (i.e., Love waves) using specialized base plates. In this regard, much less is available in the literature regarding Love waves as sources in MASW testing which means that optimum field survey parameters, the effects of near-field, and the role of seismic source have not been thoroughly investigated yet for Love waves. Given the aforementioned gaps in the literature, two aspects of MASW have been investigated. First, the role of base plate material, specifically plastic-type plates, has been studied. Field data collected from six sites along with the data from laboratory experiments and numerical simulations of hammer-plate impact were studied. The results showed that softer base plates improve the energy transfer by as much 20% and lead to minor improvements, typically one-digit numbers in relative changes, in other signal characteristics such as signal bandwidth and signal-to-noise ratio. These results were corroborated with laboratory testing and numerical models of wave propagation with different base plate materials. The second goal was to improve understanding of Love wave propagation, particularly as related to resolution capabilities from survey parameters. Rayleigh and Love waveforms were collected with multiple active seismic sources at three sites and a systematic comparison was made between the two types of waves. Also, seismic wave propagation was simulated using the research community code SPECFEM2D to further investigate their differences. The results revealed critical new information about the depth of investigation, the effects of bedrock location on near-field effects, and the role of the different survey parameters on Rayleigh and Love wave data. The depth of investigation of Love wave MASW was deeper by about 2-9 m than that of Rayleigh MASW as a result of improved minimum frequency. The minimum source offset to avoid near-field effects was comparable for both Rayleigh and Love waves (0.3-0.4 of maximum wavelength). At closer source offset locations, Rayleigh waves were more affected by near-field effects and showed an additional 10% underestimation of planar phase velocities. Overall, the results from both parts of this study provides new practical insights about some of the unexplored aspects of surface wave testing using MASW.
Temple University--Theses
31
Hemström, Maria. "Salary determination in professional labour markets /". [Uppsala] : Dept. of Economics, Uppsala University, 1998. http://lcweb.loc.gov/catdir/toc/98-183446.html.
Testo completo
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Fetterplace, Cameron. "Resisting work : Collective perspectives onequality and liberation". Thesis, Umeå universitet, Umeå centrum för genusstudier (UCGS), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-188322.
Testo completoAbstract (sommario):
Wage work, as a norm and institution, is more and more obviously incapable of fulfilling its promises: for gender equality, social integration, meaning, or even equitably meeting our basic needs. Yet, despite struggles for more, less, or better work, there is minimal public protest against work itself. Using qualitative, open-ended survey responses from 34 people who described themselves as resisting traditional work norms, this study explores the ways the participants conceive of work and their resistance to it. A feminist work-critical theoretical lens and reflexive thematic analysis as method are brought to bear on underexplored collective motivations and justifications for resisting work. The results indicate that people are not only driven by individualistic motives to resist work, but see work as in conflict with the basic needs of human connection and caring for social relationships.They also desire even more freedom from work than they have already achieved, and for this freedom to include everybody.
33
Ahammod, Shamim. "Determination of Vp, Vs, Glacial Drift Thickness and Poisson’s Ratio at a Site in Jay County, Indiana, Using Seismic Refraction and Multichannel Analysis of Surface Wave (MASW) Analysis on a Common Data Set". Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1451337593.
Testo completo
34
Shah, Amy S. M. D. "Racial Differences in Arterial Stiffness Among Adolescents and Young Adults with Type 2 Diabetes". University of Cincinnati / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1298040943.
Testo completo
35
Capper, Joseph David. "Numerical Analysis and Parameter Optimization of Portable Oscillating-Body Wave Energy Converters". Thesis, Virginia Tech, 2021. http://hdl.handle.net/10919/103861.
Testo completoAbstract (sommario):
As a clean, abundant, and renewable source of energy with a strategic location in close proximity to global population regions, ocean wave energy shows major promise. Although much wave energy converter development has focused on large-scale power generation, there is also increasing interest in small-scale applications for powering the blue economy. In this thesis, the objective was to optimize the performance of small-sized, portable, oscillating-body wave energy converters (WECs). Two types of oscillating body WECs were studied: bottom hinged and two-body attenuator. For the bottom-hinged device, the goal was to show the feasibility of an oscillating surge WEC and desalination system using numerical modeling to estimate the system performance. For a 5-day test period, the model estimated 517 L of freshwater production with 711 ppm concentration and showed effective brine discharge, agreeing well with preliminary experimental results.
The objective for the two-body attenuator was to develop a method of power maximization through resonance tuning and numerical simulation. Three different geometries of body cross sections were used for the study with four different drag coefficients for each geometry. Power generation was maximized by adjusting body dimensions to match the natural frequency with the wave frequency. Based on the time domain simulation results, there was not a significant difference in power between the geometries when variation in drag was not considered, but the elliptical geometry had the highest power when using approximate drag coefficients. Using the two degree-of-freedom (2DOF) model with approximate drag coefficients, the elliptical cross section had a max power of 27.1 W and 7.36% capture width ratio (CWR) for regular waves and a max power of 8.32 W and 2.26% CWR for irregular waves. Using the three degree-of-freedom (3DOF) model with approximate drag coefficients, the elliptical cross section had a max power of 22.5 W and 6.12% CWR for regular waves and 6.18 W and 1.68% CWR for irregular waves. A mooring stiffness study was performed with the 3DOF model, showing that mooring stiffness can be increased to increase relative motion and therefore increase power.Master of Science
As a clean, abundant, and renewable source of energy with a strategic location in close proximity to global population centers, ocean wave energy shows major promise. Although much wave energy converter development has focused on large-scale power generation, there is also increasing interest in small-scale applications for powering the blue economy. There are many situations where large-scale wave energy converter (WEC) devices are not necessary or practical, but easily-portable, small-sized WECs are suitable, including navigation signs, illumination, sensors, survival kits, electronics charging, and portable desalination. In this thesis, the objective was to optimize the performance of small-sized, oscillating body wave energy converters. Oscillating body WECs function by converting a device's wave-driven oscillating motion into useful power. Two types of oscillating body WECs were studied: bottom hinged and two-body attenuator. For the bottom-hinged device, the goal was to show the feasibility of a WEC and desalination system using numerical modeling to estimate the system performance. Based on the model results, the system will produce desirable amounts of fresh water with suitably low concentration and be effective at discharging brine. The objective for the two-body attenuator was to develop a method of power maximization through resonance tuning and numerical simulation. Based on the two- and three-degree-of-freedom model results with approximate drag coefficients, the elliptical cross section had the largest power absorption out of three different geometries of body cross sections. A mooring stiffness study with the three-degree-of-freedom model showed that mooring stiffness can be increased to increase power absorption.
36
Earle, Lieko. "Z-Spec: A broadband spectrometer for millimeter-wave astrophysics---Instrument development and results of a molecular line survey of nearby star-forming galaxy NGC 253". Connect to online resource, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3337091.
Testo completo
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Arran, Matthew Iain. "Avalanching on dunes and its effects : size statistics, stratification, & seismic surveys". Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/278773.
Testo completoAbstract (sommario):
Geophysical research has long been interdisciplinary, with many phenomena on the Earth's surface involving multiple, linked processes that are best understood using a combination of techniques. This is particularly true in the case of grain flows on sand dunes, in which the sedimentary stratification with which geologists are concerned arises from the granular processes investigated by physicists and engineers, and the water permeation that interests hydrologists and soil scientists determines the seismic velocities of concern to exploration geophysicists. In this dissertation, I describe four projects conducted for the degree of Doctor of Philosophy, using a combination of laboratory experimentation, fieldwork, numerical simulation, and mathematical modelling to link avalanching on dunes to its effects on stratification, on the permeation of water, and on seismic surveys. Firstly, I describe experiments on erodible, unbounded, grain piles in a channel, slowly supplied with additional grains, and I demonstrate that the behaviour of the consequent, discrete avalanches alternates between two regimes, typified by their size statistics. Reconciling the `self-organised criticality' that several authors have predicted for such a system with the hysteretic behaviour that others have observed, the system exhibits quasi-periodic, system-spanning avalanches in one regime, while in the other avalanches pass at irregular intervals and have a power-law size distribution. Secondly, I link this power-law size distribution to the strata emplaced by avalanches on bounded grain piles. A low inflow rate of grains into an experimental channel develops a pile, composed of strata in which blue-dyed, coarser grains overlie finer grains. Associating stopped avalanche fronts with the `trapped kinks' described by previous authors, I show that, in sufficiently large grain piles, mean stratum width increases linearly with distance downslope. This implies the possibility of interpreting paleodune height from the strata of aeolian sandstones, and makes predictions for the structure of avalanche-associated strata within active dunes. Thirdly, I discuss investigations of these strata within active, Qatari barchan dunes, using dye-infiltration to image strata in the field and extracting samples across individual strata with sub-centimetre resolution. Downslope increases in mean stratum width are evident, while measurements of particle size distributions demonstrate preferential permeation of water along substrata composed of finer particles, explaining the strata-associated, localised regions of high water content discovered by other work on the same dunes. Finally, I consider the effect of these within-dune variations in water content on seismic surveys for oil and gas. Having used high performance computing to simulate elastic wave propagation in the vicinity of an isolated, barchan sand dune, I demonstrate that such a dune acts as a resonator, absorbing energy from Rayleigh waves and reemitting it over an extensive period of time. I derive and validate a mathematical framework that uses bulk properties of the dune to predict quantitative properties of the emitted waves, and I demonstrate the importance of internal variations in seismic velocity, resulting from variations in water content.
38
Thorell, Anton. "Surf Simulation with the Shallow Water Equations : Coupling of a surfer model to a shallow water wave". Thesis, KTH, Skolan för teknikvetenskap (SCI), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-297697.
Testo completoAbstract (sommario):
This thesis covers the subject of deriving and solving the system of partial differential equations known as the Shallow Water Equations (SWE), and coupling the solutions of this equation system to a simplified model of a surfer - or any floating object, with the right choice of parameters. The SWE are generally used to analyze fluid movement on shallow areas, such as ocean waves nearing the shore, and are derived from the Navier-Stokes equations and restricted to conservation of mass and momentum in a fluid. In this project the solution to these equations was made to yield a propagating wave profile. From the solution, the steepening behaviour and the slow propagation speed of shallow water waves are explained - properties that are necessary for wave surfing. The SWE was solved with the first order accurate finite volume scheme known as the Lax Friedrichs Method (LxF), and a surfable wave is created with a suitable set of initial- and boundary conditions parameter values. LxF is also derived from the discretization of the conservation form of the SWE. The solver can also handle a non-horizontal seabed - bathymetry, but does not take into consideration friction from the seabed. A "surfer" was created as a point mass acted on by three forces: hydrodynamic drag, gravity and buoyancy. The "surfer" is made to move realistically by simulating the effect of these forces and updating position and velocity of the surfer accordingly. The surfer is made to move along with the wave.
39
Barkun, Alan N. (Alan Nicolas Glen). "The costs and effectiveness of extracorporeal gallbladder stone shock wave lithotripsy versus laparoscopic cholecystectomy : a randomized clinical trial". Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=22717.
Testo completoAbstract (sommario):
A randomized clinical trial was undertaken to compare the effectiveness and direct costs of shock wave lithotripsy (ESWL) and laparoscopic cholecystectomy (LC) for the treatment of symptomatic gallbladder stones. Over a period of 24 months from a total of 468 patients screened, 35 patients were randomized to ESWL, and 25 to LC. 32 ESWL patients were treated, all as out-patients, with a mean convalescence post-ESWL of 0.5 $ pm$ 1.2 days. In contrast, all LC patients were admitted to hospital for a mean duration of 2.8 $ pm$ 1.5 days with a mean post-operative convalescence of 18.2 $ pm$ 16.8 days as measured by research nurses. The two patient groups did not differ with respect to McGill Pain scores administered immediately after treatment. Three Quality of Life (QOL) tools improved similarly in both groups within the month following treatment. The only differences in QOL questionnaire results between both groups when administered 3 months following treatment and at six monthly intervals thereafter occurred for LC as greater incremental improvements were noted at 6 and 12 months follow-up. The overall stone disappearance rate in the ESWL group after a median of 15 months was 38%. Direct costs to the Quebec Health Care system during the study period were determined by analysis of patients in both treatment groups. In 1993 canadian dollars, average costs and their range were 2,889$ (1,704 $-5,830$) for patients undergoing LC, and 3,936 $ (2,367$--6,243 $) for patients treated by ESWL. The cost effectiveness ratios using the incremental differences in direct costs and duration of disability favoured ESWL at a cost of 58.9$/day of disability saved over the 15--18 months follow-up period. (Abstract shortened by UMI.)
40
Stocker, Mark Ryan. "Surge free added resistance tests in oblique wave headings for the KRISO container ship model". Thesis, University of Iowa, 2016. https://ir.uiowa.edu/etd/2148.
Testo completoAbstract (sommario):
Surge Free Added Resistance testing in variable head wave conditions were completed for a container ship model. The added resistance experiments include calm water, head wave, and oblique wave cases with a focus on establishing a validation benchmark for CFD codes computing the added resistance and motions of the ship model during maneuvering. The ship used is a 1/85.19 scale KRISO Container Ship, KCS, model with a length of 2.70 m. Tests were performed at the IIHR wave basin. The 20 x 40 x 4.5 m wave basin is equipped with 6 inline plunger type wave makers and a 3 degrees of freedom carriage. A 4 degrees of freedom, surge, heave, roll, and pitch free mount with a mass spring damper system was used to tow the model. Calm water tests were performed for 13 Froude numbers between 0.0867 and 0.2817. The resistance coefficients, sinkage, and trim were found for each test. The calm water results were obtained and compared to results from towing tank facilities, with traditional mounts, to estimate facility biases at the IIHR wave basin. The results show that the size difference of the IIHR model and surge free motion create magnitude differences between facilities. Head and oblique wave tests were performed at Froude number 0.26 and wave height to wavelength ratio, H/λ, of 0.0167. For all wave tests, time histories of wave amplitude, resistance, and 4 DOF were measured. Fourier analysis was completed for all time histories of waves, forces, and motions and the 0th, 1st, and 2nd harmonic amplitudes and phases are presented. All head wave results are compared to other facilities data taken in a towing tank with a traditional mount. The data from all wave heading data was analyzed with a focus on the trends with incremented wave encounter angle. Most harmonic amplitudes show good agreement between all facilities, but removal of the small model used by IIHR shows even better agreement between facilities. The oblique wave heading data shows good agreement with the only other experimental oblique wave added resistance testing. Complete uncertainty analysis was completed for select cases for calm water, head wave, and oblique wave conditions. The uncertainty showed accurate data form most wavelength settings.
41
Tao, Yu. "The earnings of Asian computer scientists and engineers in the United States". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2009. http://hdl.handle.net/1853/29633.
Testo completoAbstract (sommario):
Thesis (Ph.D)--History, Technology and Society, Georgia Institute of Technology, 2010.Committee Chair: Pearson, Willie, Jr.; Committee Member: Bauchspies, Wenda; Committee Member: Damarin, Amanda; Committee Member: Shapira, Philip; Committee Member: Wong, Raymong. Part of the SMARTech Electronic Thesis and Dissertation Collection.
42
Loder, Nicholas Mason. "An evaluation of the potential of coastal wetlands for hurricane surge and wave energy reduction". [College Station, Tex. : Texas A&M University, 2008. http://hdl.handle.net/1969.1/ETD-TAMU-3139.
Testo completo
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Röhner, Michael. "Schwallwellen infolge der Bewegung einer Begrenzungsfläche". Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2011. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-77100.
Testo completoAbstract (sommario):
Restlöcher ausgekohlter Braunkohlentagebaue werden aus landeskulturellen und ökonomischen Gründen wasserwirtschaftlich als Speicher, Hochwasserrückhaltebecken, Klärteiche, Wassergewinnungsanlagen sowie zur Naherholung genutzt. Diese Restlöcher werden zum großen Teil von aus geschüttetem Abraum bestehenden Böschungen umschlossen. Bei Wasserspiegelschwankungen neigen diese unbefestigten Böschungen zum Rutschen. Als Folge dieser Böschungsrutschungen bilden sich auf der Wasseroberfläche Wellen, die eine beachtliche Größe erreichen können. Diese Schwallwellen übertreffen in ihren Ausmaßen die Windwellen in den Tagebaurestlöchern um ein Vielfaches. Um diese Erscheinungen vorausberechnen zu können, wurden im Hubert-Engels-Laboratorium der Sektion Wasserwesen Untersuchungen durchgeführt.
Die Entwicklung einer allgemeingültigen Berechnungsmethode für die Schwallwelle bei der Bewegung eines Teiles der das Wasserbecken begrenzenden Böschung verlangt die Einführung erfassbarer Parameter wie der Breite der rutschenden Böschung, den zeitlichen Verlauf der Wasserverdrängung sowie Tiefen- und Lageverhältnisse des Beckens. Die dafür notwendigen Kennzahlen können nur näherungsweise bestimmt werden, so dass einfache Beckengeometrien, ein über die Rutschzeit gleich bleibender Verlauf der Wasserverdrängung und Erhaltung der Böschungskante einem Berechnungsverfahren zugrunde gelegt werden müssen.
Für die Berechnung des Füllschwalles auf das ruhende Wasser sind einige Verfahren bekannt geworden, die auf eine gemeinsame Gleichung für die Berechnung der Schwallhöhe zurückzuführen sind. Für die ebene Ausbreitung des Füllschwalles über Ruhewasser ergeben sieh zwei prinzipielle Abflussmöglichkeiten: Auflösung in Wellen oder brandender Schwallkopf. Diese beiden Möglichkeiten sowie der Übergangsbereich werden durch FROUDE-zahlen festgelegt.
Der Wellenkopf von Füllschwallwellen wird durch eine Einzelwelle gebildet.
Die Rutschung einer Böschung wurde durch die gleichzeitige Horizontal- und Vertikalbewegung einer Platte nachgebildet. Die Bewegung der Platte, die entstehenden Wellen und die Kräfte auf Auflaufböschung wurden durch einen Oszillografen aufgezeichnet.
Die Auswertung der Versuche ergab eine Übereinstimmung zwischen Messergebnissen und den Berechnungen nach den Gesetzen des Füllschwalls. Die sekundlich verdrängte Wassermenge pro Breiteneinheit und die Ruhewassertiefe bestimmen die entstehenden Schwallwellen. Ein Einfluss der vertikalen Bewegungskomponente ist im untersuchten Bereich nicht nachweisbar. Die dynamischen Kräfte auf die Abschlussböschung können durch den Impuls der Einzelwelle dargestellt werden.
Die räumliche Ausbreitung der Schwallwellen wurde in einem Modell untersucht. Dabei wurde festgestellt, dass die größten Wellenhöhen in der Richtung der Bewegung der Platte auftreten, während die Wellenhöhen in seitlichen Ausbreitungsrichtungen kleiner sind.
Berechnungsansätze für die maximale Wellenhöhe der front wurden ermittelt.
Als Ergebnis wurde ein Berechnungsverfahren entwickelt, welches ausgehend von den Parametern dar Rutschung, die Eigenschaften der Schwallwellen einschließlich der durch sie hervorgerufenen Belastungen auf der Auflaufböschung ermöglicht. Mit diesem Berechnungsverfahren ist es möglich, Böschungen wirtschaftlich zu gestalten und schädliche Rückwirkungen auf das Staubecken durch Schwallwellen zu vermeiden. Bisher notwendige Kosten für eine sehr flache Gestaltung der Böschung können entfallen. Gleichzeitig bleibt ein größerer nutzbarer Stauraum erhalten.
Die Digitalisierung der vorliegenden Arbeit durch die Sächsische Landesbibliothek - Staats- und Universitätsbibliothek Dresden (SLUB) wurde durch die Gesellschaft der Förderer des Hubert-Engels-Institutes für Wasserbau und Technische Hydromechanik an der Technischen Universität Dresden e.V. unterstützt.
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Godwin, Steven Benjamin. "Hot Springs Inflow Controlled by the Damage Zone of a Major Normal Fault". BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/7724.
Testo completoAbstract (sommario):
Spring water inflow is distinct at Pah Tempe Hot Springs (also known as Dixie Hot Springs) situated within the damage zone of the Hurricane Fault in Timpoweap Canyon in Hurricane, Utah. Excising of the footwall by the Virgin River has created Timpoweap Canyon and allowed an unusual opportunity to study the spring inflow in relation to the fault damage zone. While correlation of these springs with the damage zone and visible fracture patterns on the canyon wall has been made, no subsurface faulting has been imaged to verify connection to these visible fractures and spring inflows (Nelson et al., 2009). The stream was logged and contoured to note the varying locations of spring water inflows in contrast with unsaturated Virgin River water. Seismic surveys were conducted and subsurface profiles made to locate offsets and faults. Photogrammetry was conducted and a three-dimensional model of the canyon and cliff wall was created to facilitate remote fracture mapping of this wallSubsurface features correlate to fractures, spring water inflow locations, and surface faults mapped by Biek (2002). This suggests that faulting and fracturing from the Hurricane Fault provides subsurface conduits for these thermal waters to rise. In one area in the stream, thermal inflow correlates with both subsurface offsets and major surface fractures. Numerous correlations between just spring water entry and subsurface offsets or surface fractures are also found. Fracture and fault density is atypical at Pah Tempe as these features do not diminish with distance from the main strand of the fault. This has led to the Sevier Orogeny accounting for creating the observed fracture conduits at Pah Tempe. Fractures in the canyon wall at Pah Tempe open west to east. This is indicative of the maximum horizontal compressive stress of southern Utah being north to south (Zoback and Zoback, 2015). Therefore the spring inflow at Pah Tempe is likely a result of the damage from the Hurricane Fault creating conduits for spring water to rise, rather than the Sevier Orogeny.
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Sakib, Salman. "Design Optimization and Field Performance Evaluation of the Wave Suppression and Sediment Collection (WSSC) System| Computational Fluid Dynamics (CFD) Modeling, Surface Elevation Table (SET) Survey, and Marker Clay Study". Thesis, University of Louisiana at Lafayette, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10618338.
Testo completoAbstract (sommario):
Coastal erosion is an issue of concern for Louisiana, in the United States, and for all other coastal communities in the world. Among many coastal protection and restoration technologies, shoreline protection structures focus on wave reductions to prevent waves from hitting the coastal landforms directly. A novel technology called the Wave Suppression and Sediment Collection (WSSC) system focuses on solving the limitations of conventional shoreline protection structures regarding mobility, constructability, and sustainability. The primary goals of this study are to optimize the WSSC units for wave reduction and sediment transport and to verify the performance of this technology in an actual field environment. Computational Fluid Dynamics (CFD) simulations were carried out to optimize the designs of the units in terms of pipe diameters and face slope. Results have indicated that increasing pipe diameters decreases wave reduction and increases sediment transport ability of the units. Further, it was found that increasing the face slope decreases the wave reduction ability; however, no effect was found on the sediment transport efficiency. Parametric optimization suggested that a porosity (open-to-total area ratio) of 30% should yield satisfactory wave reduction and balanced sediment transport by the units. For better output from the units, the designs should be modified according to site-specific requirements. Field site investigations involved Surface Elevation Table (SET) surveying and marker clay experiments. SET surveys showed significant sediment accumulation over eleven months behind the units. Also, no significant change was observed at the control site over three months, which proves the effectiveness of the technology in stopping erosion and facilitating land building. Marker clay experiments validated the SET measurements and proved that there was a significant amount of sediment deposition over the white Feldspar clay layer over six months. This strengthens the conclusion that the WSSC units can be used successfully in a Louisiana marsh environment to battle coastal erosion and land loss.
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Choonoo, John Gerald. "A comparative analysis of inequality and poverty among urban African, coloured, and Indian families and their labor market experiences during the Apartheid years 1975-1985 /". Access Digital Full Text version, 1995. http://pocketknowledge.tc.columbia.edu/home.php/bybib/11790052.
Testo completoAbstract (sommario):
Thesis (Ed.D.)--Teachers College, Columbia University, 1995.Includes tables. Typescript; issued also on microfilm. Sponsor: Thomas Bailey. Dissertation Committee: Francisco Rivera-Batiz. Includes bibliographical references (leaves 201-212).
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Madueme, Peace C. "Predictors of Exaggerated Exerise-Induced Systolic Blood Pressures in Young Patients After Coarctation Repair". University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1337887220.
Testo completo
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Bradley, Samuel. "Chief executive officer compensation and the effect on company performance in a South African context". Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1001637.
Testo completoAbstract (sommario):
The goal of this research was to determine, in a South African context, whether there is any correlation between chief executive officer compensation and the performance of the company. For the purposes of the research , the compensation of chief executive officers was broken down into three components: salary, bonus and "other" remuneration, while company performance was measured on return on equity, return on assets and earnings per share figures. Studies on this topic have been carried out in other countries, most notably in the United States of America and the United Kingdom. It appears that no research of a similar nature has been carried out in South Africa. Data in respect of the forty largest listed companies in South Africa were collected over a period of five years. The econometric models used for the research were based on models identified in the literature study. The data were then analysed for evidence of a correlation between chief executive officer compensation and the performance of the company. The results of this study indicate that there is no linear relationship between chief executive officer compensation and company performance variables. The econometric models did, however, show correlations between certain variables, taking into account the other predictor variables in the model. Evidence of correlations between age and experience and compensation was also found , which may present potential avenues of research to scholars in the future.
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Liquori, Riccardo. "Numerical and experimental study of a heaving buoy for modelling a wave energy converter for WECfarm project". Master's thesis, Alma Mater Studiorum - Università di Bologna, 2020.
Cerca il testo completoAbstract (sommario):
Waves from Ocean are a huge unexploited energy resource, and the potential for extracting energy from waves is significant. Oceanic surface waves carry a much higher energy density, sometimes by two orders of magnitude, than solar and wind. For this reason, different Wave Energy Converter (WEC) designs have been developed in recent years. Among all the technologies available to convert wave energy, the point-absorber is one of the most promising solutions today, due to its ease of both fabrication and installation. In most cases, the WEC will not be installed in single units but arranged in parks to extract an important amount of wave power. In the former WECwakes project, a number of 25 WEC buoys were arranged in different geometric configurations and tested to several wave conditions. Each WEC was composed of a hemispherical ended cylindrical buoy designed to heave only. Essential data was obtained about the importance of WEC array effects. Nevertheless, improvement of the understanding regarding the WEC array effects by providing high quality experimental data is desired. Therefore, the WECfarm project was established. A first target in the progress is to improve the original WEC design.The main aim of this master dissertation was to validate the improved features of a new-shape WEC design to increase radiation effect and to maximize the wave-WEC interactions, the WEC-WEC interactions and to reduce surge force on the WEC structure. By means of a Boundary Element Method model (Nemoh) included in openWEC, an easy-to-use WEC simulation tool, a numerical study was performed to evaluate the performance of the designed WEC unit. A solution is obtained which allows to predict the device behaviour in regular waves. At the end, a validation of the model is carried out via experimental studies in the wave flume of Coastal Engineering Research Group of Ghent University to evaluate the numerical results of the WEC unit.
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Tucker, Kylie. "Methodological considerations and the effect of pain on the H-reflex and maximal M-wave in the human triceps surae". Click here to access, 2006. http://thesis.library.adelaide.edu.au/public/adt-SUA20060704.165047/index.html.
Testo completoAbstract (sommario):
Thesis (Ph.D.) -- University of Adelaide, School of Molecular and Biomedical Science, Discipline of Physiology, 2006.Includes author's previously published papers. "June 2006" Includes bibliographical references. Also available in a print form.