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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Field studies comparing SASW, beamforming and MASW test methods and characterization of geotechnical materials based on Vs

Yuan, Jiabei 13 October 2011 (has links)
Estimating S-wave velocities (Vs) from Rayleigh-wave velocities (VR) is widely used in field seismic testing for geotechnical engineering purposes. In this research, two widely used surface-wave methods, the Spectral-Analysis-of-Surface-Waves (SASW) and Multichannel-Analysis-of-Surface-Waves (MASW) methods, are evaluated and compared in field experiments. An experimental parametric study was undertaken of the SASW and MASW methods. Conventional seismic sources in the SASW method are sledge hammers, bulldozers and vibroseises. For MASW testing, sledge hammers and small shakers are usually used as the seismic sources. In this research, MASW testing was performed with traditional and non-traditional sources at a site owned by the City of Austin, Texas. Experimental dispersion curves and Vs profiles from SASW tests are used as references for the field parametric study with the MASW method. The source type, source offset, receiver spacing and number of receivers were varied to evaluate the impact of each variable on the field experimental dispersion curve. Two type of receivers, 1-Hz and 4.5-Hz natural-frequency geophones, were also compared in these tests. A second part of this research involved studying the use of characterizing geotechnical materials based on Vs. This work included two projects. The first project involved basalt on the Big Island of Hawaii. To develop empirical ground motion prediction models for the purpose of earthquake hazard mitigation and seismic design on the Big Island, the subsurface site conditions beneath 22 strong motion stations were investigated by SASW tests. Vs profiling was performed to depths of more than 100 ft. Vs30, the average Vs in the top 30 m, was also calculated to assign NEHRP site classes to different testing locations. Different materials, mainly thought to be stiff basalt, were characterized and grouped based on the Vs values. These groups were then compared with reference curves for sand and gravel (Menq, 2003) to differentiate the groups. The second project dealing with charactering geotechnical materials based on Vs involved of soil/rock profiles at a project site in British Columbia, Canada. The goals in terms of this research were to: (1) compare the Vs profiles from the different test locations to investigate the stiffnesses of different geologic materials, the variability in the material stiffnesses, and the estimated depth to bedrock, and (2) to compare the Vs profiles to existing geological and geotechnical information such as nearby boreholes, cone penetration tests and seismic cone penetration tests. Good agreement between SASW Vs profiles and boring records is expected when lateral variability at the site is low. However, when lateral variability is significant, then the difference between localized measurements, like borings and CPT results, and global measurements, like SASW Vs results, can further contribute to understanding the site conditions as shown at the site in British Columbia, Canada. / text
62

Entwurfsaerodynamische Studien an Tragflügelkonfigurationen im Hochgeschwindigkeitsbereich mit evolutionären Algorithmen

Klein, Michael 20 June 2000 (has links)
Diese Arbeit stellt eine Anwendung und Erweiterung evolutionärer Methoden auf die aerodynamische Optimierung dar. Durch die Implementation der natürlichen Anpassungsmethode der Evolution in einen Computeralgorithmus kann diese Methode auch für die Aerodynamik nutzbar gemacht werden. Im Mittelpunkt steht die Geometriedefinition, deren Qualität für die Aerodynamik durch die evolutionären Methoden beurteilt werden kann. Zu diesem Zweck werden die evolutionären Methoden, die genetischen Algorithmen und die evolutionäre Strategie für die notwendigen Optimierungsmaßnahmen verwendet. Die Funktionalität und Wirkungsweise wird ausführlich innerhalb der ersten Kapitel vorgestellt. Den evolutionären Methoden wird eine effiziente Geometriedefinition aerodynamischer Konfigurationen zur Seite gestellt. Diese stützt sich ausschließlich auf analytisch definierte Kurven und Formen. Dadurch kann der Parameterraum klein gehalten und für die evlutionären Optimierungsmethoden nutzbar gemacht werde! n. Bewußt wird hier auf Studien zur Steigerung der evolutionären Konvergenzgeschwindigkeit verzichtet. Der Verlauf der optimierten Geometriparameter entlang einer Paretofront gibt wichtige Hinweise auf die grundsätzlich benötigte Gestaltungfreiheit von Konfigurationen im Bereich optimaler aerodynamischer Effizienz. Somit kann die Arbeit mit genetischen Algorithmen wesentlich zur Erweiterung der praktischen Wissensbasis beitragen. In dieser Arbeit wird eine einzige Zahl, das Verhältnis von Auftrieb zu Widerstand (L/D), optimiert. Bei Strömungsrechungen mit dem Euler-Verfahren wird nur der reibungsfreie (induzierter und Wellen-) Widerstand berücksichtigt. In verfeinerten Untersuchungen unter Nutzung von Navier-Stokes-Verfahren wird zusätzlich auch der Reibungsanteil des Widerstandes minimiert. Die durchgeführten Untersuchungen beziehen sich auf Profile und Tragflügel für Unter- und Überschallströmungen. In zukünfitgen Arbeiten legt es die aerodynamsiche Wissensbasis nahe, auch den Verlauf der Druckverteilungen entlang von Profilen und Flügelschnitten vorzuschreiben, um günstige Resultate für die Reibungseinflüsse zu erhalten. Diese inverse Komponenten der Optimierung (weitgehende Vorgabe des Resultates der Umströmung und Auffinden einer mit dieser Strömung kompatiblen Geometrie) bildet eine attraktive Erweiterung des Anwendungsbereichs der hier vorgestellten Rechnungen mit genetischen Algorithmen. Die Optimierung mit Hilfe evolutionärer Methoden ist sehr rechenintensiv. Aus diesem Grunde verbreitert sich das Anwendungsspektrum dieser Methoden parallel zu Rechnerentwicklung. Da die Computertechnologie innerhalb kürzester Zeit enorme Fortschritte macht, ist mit einer verstärkten Anwendung auch innerhalb der Strömungsmechnik in absehbarer Zeit zu rechnen.
63

A profile of soccer injuries in selected league amateur indoor and outdoor soccer players in the greater Durban area

Archary, Nigel Wayne January 2008 (has links)
Dissertation submitted to the Faculty of Health in partial compliance with the requirements for the Masters Degree in Technology: Chiropractic, at the Durban University Of Technology, 2008. / Objectives: To determine a profile of soccer injuries prevalent in amateur Indoor and Outdoor soccer players in the greater Durban areas. Methods: This study used the Outdoor Supersport corporate league and the Kwa-Zulu Natal (KZN) Indoor soccer league. A total of 103 out of a possible 147 players participated in the study which included 41 Outdoor and 62 Indoor players. The Indoor soccer players were contacted to complete the questionnaire at their match days at the Gale street Indoor soccer arena and the Outdoor players were contacted during their training sessions and/or match days. The researcher was present to answer any questions posed by the participants. In the case of participants having difficulty in understanding English, a bilingual Zulu translator accompanied the researcher in every interaction with the participants. Results: Out of a total of 103 participants, the foot/ankle (62.1%) was the most frequently injured site. This was followed closely by the knee (55.3%). The rest of the sites in descending order were wrist, back, head, elbow, shoulder, chest, genital and abdomen. All participants reported a first injury, 69 participants reported a second injury and 27 participants reported a third injury. Outdoor soccer players reported the knee as being the most affected area, while Indoor soccer players injured the foot/ankle frequently. Furthermore, age was stated as a significant positive correlation when compared with number of sessions missed, meaning the older the participants, the more sessions they missed. The findings suggest that the use of protective equipment can decrease injury rates due to the use of ankle guards decreasing missed sessions. Conclusion: The profile of soccer injuries in selected amateur league Indoor and Outdoor soccer players in the greater Durban area has been described in this study. In terms of number of injuries, there seems to be no significant differences iv between Indoor and Outdoor soccer players. With regard to site of injuries, the lower limb was affected more than any other body part. The Outdoor players showed more knee injuries than the Indoor players who showed higher incidences of foot/ankle injuries.
64

The optical characterisation of liquid crystal structures

McSweeney, Matthew J. P. January 1996 (has links)
No description available.
65

Geobacillus genties bakterijų kamienų giminingumo nustatymas visų ląstelės baltymų analizės metodu / Relationship determination of the strains of the genus geobacillus by electrophoretic whole cell protein profile analysis

Jasinskytė, Džiuginta 20 June 2014 (has links)
Santrauka Visų ląstelės baltymų analizė – tai metodas teikiantis fenotipinės informacijos. Jis plačiai naudojamas grupuoti bakterijų kamienus, nustatyti jų pirminį identitetą. Rezultatų patikimumas daugeliu atvejų prilygsta DNR-DNR hibridizacijai – pagrindiniam genotipinės informacijos metodui. Tuo pačiu visų ląstelės baltymų analizės metodas yra greitai atliekamas ir pigus. Dėl šių priežasčių metodas plačiai naudojamas medicininės diagnostikos, o taip pat su maisto pramone susijusiose laboratorijose. Šiuolaikiniame pasaulyje pramonėje labai svarbūs yra termostabilūs fermentai, o Geobacillus genties bakterijų kamienai būdami termofilai, yra tokių fermentų producentai. Dėl šios priežasties Geobacillus gentis yra aktualus tyrimų objektas. Labai svarbu tiksliai identifikuoti kamienus produkuojančius tiriamus fermentus. Vienu iš pirminio identifikavimo būdų galėtų būti visų ląstelės baltymų analizės metodas. Šiame darbe buvo parodyta, kad Geobacillus genties kamienų tarpusavio panašumas gali būti nustatytas visų ląstelės baltymų analizės metodu. Tarp G. stearothermophilus rūšies kamienų visų ląstelės baltymų elektroforetinių profilių panašumas buvo apie 80% ir atitiko DNR-DNR hibridizacijos rezultatus. Taip pat sutapo ir 22 kamieno panašumas su tipiniu G. vulcani kamienu: WCPP parodė 84% panašumą, DNR-DNR hibridizacija – 93,9%. Pagal visų ląstelės baltymų analizės metodą gauti rezultatai paneigė G. stearothermophilus 10 DSM 13240 kamieno priklausomybę šiai rūšiai. Pagal panašumo... [toliau žr. visą tekstą] / Summary Electrophoretic whole-cell protein profile analysis (WCPP) – is a method providing phenotypic information. It is widely used to group bacterial strains and estimate their primal identity. In most cases reliability of this method is equal to DNA-DNA hybridization – that is the main method of genotypic information. WCPP is performed quickly and it is cheap. Therefore this method is widely used in laboratories of medical diagnostic and laboratories related to food industry. In modern world termostable enzymes are very important in industry, whereas thermophilic bacterial strains of the genus Geobacillus are producers of these enzymes. Consequently genus Geobacillus is an actual object of research. It is very important to strictly identify bacterial strains producing needed enzymes. One of the primal ways for identification of this genus could be WCPP. During this work it was shown that similarity of strains of the genus Geobacillus can be determined by WCPP. There was an 80% similarity among strains of G. stearothermophilus. These results matched with DNA-DNA hybridization of these strains. Also there were similar results of WCPP and DNA-DNA hybridization between strain 22 and typical strain of G. vulcani: 84% and 93,9% respectively. Results of WCCP denied dependence of strain G. stearothermophilus 10 DSM 13240 to this species. According to similarity dendrogram this strain should be assigned to G. vulcani because of its 97% similarity to this species. There were also... [to full text]
66

Profile changes in orthodontic patients following mandibular advancement surgery

Tsang, Susan 04 July 2006 (has links)
Purpose: To define initial hard and soft tissue convexity necessary for profiles to consistently improve after mandibular advancement and to assess if pre-surgical lower incisor inclination (IMPA) affects profile change. Methods: 20 general public, 20 orthodontists, and 20 oral surgeons used a Likert scale to rate attractiveness of before and after treatment profiles of mandibular advancement patients. Spearman’s correlation tested for relationships between amount of profile change and varying ANB, profile angle and pre-surgical IMPA. Wilcoxon test compared extraction and non-extraction profile changes. Results: There was a tendency for inverse correlations between profile change and profile angle, but was not statistically significant any of the 3 groups. There was a tendency for positive correlations between profile change and ANB, but was considered significant only for orthodontists. Orthodontists, oral surgeons and the general public found profiles consistently improved when profile angles were ≤159º, ≤158º and ≤157º, respectively. Orthodontists and oral surgeons found profiles consistently improved when ANB angles were ≥5.5º and ≥6.5º, respectively. Profile worsening increases 2.6 to 5.0 times when profile angles exceeded thresholds, and 4.5 to 7.9 times when ANB angles were less than thresholds. No difference in IMPA or profile change in extraction and non-extraction groups. Conclusion: Extractions are not predictive of a greater surgical profile change. Pre-treatment profile angles <160º and ANB >6º are necessary for consistent improvements after surgery.
67

Modification of the Naval Postgraduate School Lidar System

Gunal, Murat 09 1900 (has links)
The views expressed in this thesis are those of the author and do not relfect the offical policy or position of the Department of Defense or the U.S. Government. / Previous modifications were made to the Naval Postgraduate School (NPS) Lidar System to enable comparison of lidar returns with radiosonde vertical profiles. Inaccuracies due to flexing of the lidar mounting structure limited observation of correlation between lidar and balloon data. Reconstruction with anew telescope and integral mounting now provides stable overlap of laser illumination and receiver field-of-view while maintaining eye safety. This revised system permits more measurement of profile correlation. Both day and night lidar measurement series have been compared with concurrent radiosonde launches in the Monterey Bay area. Maximum ranges from clouds greater than 3500 meters by day and greater than 5000 meters by night have been achieved. Within this range comparison can be made with moderate accuracy with the temperature and pressure profile boundary layer ceiling. Recommendations are made for future enhancement of sensitivity of correlation.
68

PStorM: Profile Storage and Matching for Feedback-Based Tuning of MapReduce Jobs

Ead, Mostafa January 2012 (has links)
The MapReduce programming model has become widely adopted for large scale analytics on big data. MapReduce systems such as Hadoop have many tuning parameters, many of which have a significant impact on performance. The map and reduce functions that make up a MapReduce job are developed using arbitrary programming constructs, which makes them black-box in nature and prevents users from making good parameter tuning decisions for a submitted MapReduce job. Some research projects, such as the Starfish system, aim to provide automatic tuning decisions for input MapReduce jobs. Starfish and similar systems rely on an execution profile of a MapReduce job being tuned, and this profile is assumed to come from a previous execution of the same job. Managing these execution profiles has not been previously studied. This thesis presents PStorM, a profile store that organizes the collected profiling information in a scalable and extensible data model, and a profile matcher that accurately picks the relevant profiling information even for previously unseen MapReduce jobs. PStorM is currently integrated with the Starfish system, providing the necessary profiles that Starfish needs to tune a job. The thesis presents results that demonstrate the accuracy and efficiency of profile matching. The results also show that the profiles returned by PStorM lead to Starfish tuning decisions that are as good as the decisions made by profiles collected from a previous run of the job.
69

Profile changes in orthodontic patients following mandibular advancement surgery

Tsang, Susan 04 July 2006 (has links)
Purpose: To define initial hard and soft tissue convexity necessary for profiles to consistently improve after mandibular advancement and to assess if pre-surgical lower incisor inclination (IMPA) affects profile change. Methods: 20 general public, 20 orthodontists, and 20 oral surgeons used a Likert scale to rate attractiveness of before and after treatment profiles of mandibular advancement patients. Spearman’s correlation tested for relationships between amount of profile change and varying ANB, profile angle and pre-surgical IMPA. Wilcoxon test compared extraction and non-extraction profile changes. Results: There was a tendency for inverse correlations between profile change and profile angle, but was not statistically significant any of the 3 groups. There was a tendency for positive correlations between profile change and ANB, but was considered significant only for orthodontists. Orthodontists, oral surgeons and the general public found profiles consistently improved when profile angles were ≤159º, ≤158º and ≤157º, respectively. Orthodontists and oral surgeons found profiles consistently improved when ANB angles were ≥5.5º and ≥6.5º, respectively. Profile worsening increases 2.6 to 5.0 times when profile angles exceeded thresholds, and 4.5 to 7.9 times when ANB angles were less than thresholds. No difference in IMPA or profile change in extraction and non-extraction groups. Conclusion: Extractions are not predictive of a greater surgical profile change. Pre-treatment profile angles <160º and ANB >6º are necessary for consistent improvements after surgery.
70

Ozone concentration profile retrieval from ground-based high-resolution thermal infrared spectra.

Van Delst, Paul F. January 1996 (has links)
Simulations of the Atmospheric Emitted Radiance Interferometer (AERI), a ground-based, high-resolution infrared detection system, are used to produce retrieved atmospheric ozone concentration profiles. A line-by-line transmittance model, FASCD3P, is used for the forward model and a maximum likelihood retrieval scheme is employed for the inverse model. An a priori data set consisting of 83 midlatitude winter ozone sondes is used to condition the inversion. Three iterations are required to reduce the radiance residuals to less than the instrument noise. The retrieval accuracy below 300mb is within 25% of truth. Above 300mb, variance within the a priori data is the dominant source of retrieval error. This is due to the number of retrieved layers (27) being higher than the amount of independent information present in the radiance spectra (approximately 4) so much of the retrieval information above 300mb comes from the a priori data.

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