Aligning two images by point to point correspondence is a hard optimization problem. It can be solved using t-Extremal Optimization or with a modification of this method called Fitness threshold accepting. In this work these two methods are tested and compared to see whether one of the methods should be preferred for image alignment. Since real image data is almost always noisy the performance of the methods under conditions like noisy and outlying data is analyzed too.

Auditory evoked potentials (AEPs) have become commonly used to measure hearing thresholds in fish. However, it is uncertain how well AEP thresholds match behavioral hearing thresholds and what effect variability in electrode placement and tank composition has on AEPs. In the first experiment, the effect of testing tank composition and electrode placement on AEPs was determined by recording AEPs in the same individual fish in a steel and PVC cylindrical testing tank, and simultaneously recording AEPs from four locations and two different depths on each of 12 goldfish, Carassius auratus. Results from these studies show that tank composition has an effect AEP strength and hearing thresholds, with steel producing lower thresholds for all frequencies. Electrode placement and depth showed no significant effect on hearing thresholds.In the second experiment, the hearing sensitivity of 12 goldfish was measured using both classical conditioning and AEPs in the same setup. For behavioral conditioning, the fish were trained to reduce their respiration rate in response to a 5s sound paired with a brief shock. Once the behavioral audiogram was completed, the AEP measurements were made without moving the fish. The same sound stimuli were presented and the resultant evoked potentials were recorded for 1,000-6,000 averages. AEP input-output functions were then compared to the behavioral audiogram to compare techniques for estimating behavioral thresholds from AEP data. Results show a large range in variability between behavioral and evoked potential thresholds between fish, with the linear regression evoked potential analysis method producing closer thresholds to behavioral methods. In the third study, the effects of masking were examined on the behavioral and evoked potential audiograms. Behavioral thresholds were first determined with a constant masking noise for two frequencies, followed by threshold measurements with no masking noise.

In aerospace industry and other major mechanical industry systems, engineering components that are subjected to cyclic loads often lead to progressive crack growth that eventually results in struc-tural fracture. The damage tolerance design which is based on the assumption of pre-existed flaws in a structure is an important approach in aircraft industry since it is impossible to have flaw-free manufactured components.In this thesis work, an evaluation of crack propagation models was carried out. Fatigue crack growth threshold and fatigue crack growth rate models were evaluated. A method to present ex-perimental data available was developed to evaluate uncertainties in fatigue life models for more accurate predictions. Currently, a software that is used for predicting crack propagation life is NASGRO. The study has been made for two types of materials: a nickel-iron-based alloy (Inconel 718 forging) and titanium alloys (Ti 6-4 both forging and casting).A threshold model is in the normal case developed for each temperature. A method to model fatigue threshold (ΔKth) has been suggested by assuming temperature independence of ΔKth. In this method, a new threshold model was created by making use of an A/P (Actual/Predicted) plot so that all measured threshold values are on the conservative side of the minimum model. With this method, an understanding of fatigue threshold model was improved over the other method due to the possibilities to model ΔKth with average and minimum threshold values for each load ratio (ΔKth, R).Moreover, a method to investigate which set of parameters that best represent the crack growth behaviour has been suggested. In this method the best set of parameters were chosen to be the set of parameters giving the best fit to the available (da/dN, ΔK) points. The comparison between this method and the method with the set of parameters that give minimum scatter in the A/P values was done.Crack growth rate da/dN log curves were plotted as function of stress intensity range ΔK for R-ratio values ranging from -2 to 0.9 for the two different methods. A distinctive difference between the two methods was observed in Paris region at high temperatures (5500C-6500C) which becomes more obvious at lower R-ratios. Predicting crack propagation rate model with set of parameters giving minimum standard deviation in da/dN points was shown to be less conservative than that of parameter sets giving lowest scatter in A/P. Using both evaluation methods, da/dN versus ΔK plots of Inconel718forging were compared to da/dN (ΔK) plots for the pre-existing data at 5500C for R-ratios ranging from 0 to 0.8. An overall R-ratio influence was observed throughout for both ΔKth and da/dN.

This dissertation investigates the hypothesis that the more vowel-like a consonant is, the more difficult it is for listeners to classify it as geminate or singleton. A perceptual account of this observation holds that more vowel-like consonants lack clear markers to signal the beginning and ending of the consonant, so listeners don’t perceive the precise duration and consequently the phonological contrast may be neutralized in some languages. Three experiments were performed to address these questions using data from Persian speakers. In Experiment I, four speakers produced singleton and geminate tokens of the voiced oral consonants [d,z,n,l,j] and the glottals [h] and glottal stop at three speaking rates. It was found that Persian speakers do distinguish geminate durations from singleton durations for all manners even at very fast speaking rates, and vowels preceding geminates are slightly longer than those preceding singletons. Speaking rate had more of an effect on geminates than on singletons for all segments studied: the durations of the geminates decreased more in fast speech than the durations of the singletons did. In Experiment II, listeners heard manipulated continua of consonants ranging from singletons to geminates. Subjects’ identification curves were modeled using the cumulative Gaussian model. The modeled standard deviation was interpreted as the breadth of the perceptual threshold, and a broader threshold understood to indicate a less distinct perceptual boundary between the two categories. Obstruents [d,z] had smaller breadth values than the sonorants [n,l,j], and the glottals had the largest breadth values of all. This indicates that while sonorants were more difficult for listeners to categorize than obstruents, the glottals were the most difficult to categorize of the segments tested. Experiment III tested whether the modification of a specific parameter, the formant transition duration, would affect the perceptibility of the geminate/singleton contrast. A single token containing the glide [j] was manipulated to produce three different continua, each having a distinctly different manipulated transition: short, normal or long. It was found that the longer the transition was, the broader the perceptual threshold, thus making the consonant harder to categorize. / text

Acoustic emission is a widely used nondestructive technique for identification of structural damage. The AE technique relies on transient energy waves generated by the materials during their failure. As for soils, the basic causes of acoustic emission are the mechanisms which are responsible for shearing of soils. Mobilization of shear strength within a soil itself and the interaction of the soil with the adjacent natural or construction materials are directly related to the level of acoustic emission in soils. It is envisioned that acoustic emission signals in deforming soils can be used as an early warning sign in real time landslide-monitoring systems.This thesis study uses a laboratory experimental setup to record the acoustic emission signals emitted during the shearing of cohesionless soils. Several tests were performed with different rates of shearing with parallel (horizontal) and perpendicular (vertical) placement of the AE mote- sensor with respect to the shear plane. Since the original raw signals recorded contain large amounts of noise, it is necessary to de-noise them. The current study uses wavelet and FFT to de-noise the original signals. The filtered signals obtained using wavelet analysis and FFT are compared to determine the suitability of the two techniques. The peak AE values and the time taken to observe an initial visible peak under different conditions are reported in this study. It is observed that relatively faster rates of shearing generate more AE signals compared to slower rates of shearing. In addition, the rapid shearing produces initial visible peak AE activities within a short period of time than in slow rate of shearing.

Background: The need to find the underlying causes to handball injuries and to develop injury prevention programs is great. In other sports a relationship between maximal oxygen uptake (VO2 max) and injury have been seen. Purpose: To examine the relationship between VO2 max and/or lactate threshold and injuries in elite handball players. Methods: A prospective, non experimental correlational study was conducted. Thirty elite handball players and handball high school players were included. Injuries and test results for VO2-max, lactate threshold and potential confounders ( re-injury of the previous injury, re- injury of previous injury of the lower limb, age, BMI and legs and core strength for the high school players) were registered during the season 2014-2015. A bivariate analysis using Spearman's rank correlation calculation was conducted. Twenty-six respectively 11 of the players had data on VO2-max, respectively lactate threshold. Confounders that showed connection with injuries or injuries in the lower extremity were analyzed for the bivariate correlation with VO2-max and lactate threshold. Results: No significant correlation was found between VO2-max respectively lactate threshold and injury. Significant correlations were seen between previous injury respectively previous injury to the lower extremity and to get a re-injury. A significant correlation were seen between re-injury of a previous injury in the lower limb and VO2-max. Conclusions: Significant associations were seen between re- injury of earlier injury and between re-injury of the lower extremity and VO2-max and should therefore be considered in the clinical practice. Larger studies are needed to clarify the relationship between VO2-max and lactate threshold and injuries. / Bakgrund: Behovet att hitta bakomliggande orsaker till handbollsskador för att kunna utforma skadepreventiva åtgärder är stort. I andra idrotter har ett samband mellan maximal syreupptagningsförmåga (VO2-max) och skador kunnat ses. Syfte: Att undersöka samband mellan VO2-max och/eller laktattröskelvärde och skador hos elithandbollspelare. Metod: En prospektiv icke experimentell sambandsstudie utfördes. Trettio elithandbollsspelare och handbollsgymnasiespelare inkluderades. Skador och testresultat för VO2-max och laktattröskel samt tänkbara konfounders (återskada av tidigare generell skada, återskada av tidigare skada i nedre extremitet, ålder, BMI och ben och bålstyrka för gymnasiespelarna) registrerades under matchsäsongen 2014-2015. En bivariat analys med Spearmans rangkorrelationsberäkning utfördes. Tjugosex respektive 11 av spelarna hade data på VO2-max respektive laktattröskelvärde. Konfounders som visade samband med generella skador eller skador i nedre extremiteten analyserades bivariat för samband med VO2-max och laktattröskelvärde. Resultat: Inga signifikanta samband fanns mellan VO2-max respektive laktattröskelvärde och skador. Signifikanta samband fanns för tidigare generella skador respektive tidigare skada i nedre extremiteten och att återfå densamma samt mellan återskada av tidigare skada i nedre extremiteten och VO2-max. Konklusion: Signifikanta samband fanns för återskada av tidigare skada samt mellan återskada i nedre extremiteten och VO2-max vilket bör beaktas i den kliniska vardagen. Större studier behövs för att klargöra det sambandet mellan VO2-max respektive laktattröskel och skador.

Drainage area is a measure of the number of acres feeding into a creek. Drainage area threshold is the amount of acreage required for the creek to be included on a map. Watersheds mapped according to higher drainage area thresholds will show creek systems that are shorter and concentrated at the bottom of the watershed. Watersheds mapped according to lower drainage area thresholds show creek systems that are longer and extend further up the watershed. Since all watersheds are subject to different land uses, soil types, geology, etc., they should be mapped according to different drainage area thresholds. Headwaters are where creeks begin. There is empirical evidence that properly functioning headwaters significantly reduce erosion, improve water quality, slow stormwater flows, and provide habitat. If municipalities use lower drainage area thresholds to define their creeks, they can include more headwaters in their creek setback requirements. This professional report identifies the Harris Branch watershed as being under relatively more pressure to develop and exhibiting more environmental risk than other watersheds in Austin, Texas’ Desired Development Zone. Creeks in the watershed are redrawn according to reduced drainage area thresholds using a simple ArcGIS analysis. The analysis reveals a critical mass where creek setbacks appear to be too extensive. If creeks with a drainage area of 5 acres are protected by development code, the setbacks created have excessive branching that could be too restrictive for development. A critical mass ratio should be considered when determining which drainage area threshold is most appropriate for a watershed. The critical mass ratio is equal to the number of branches allowed per a specified distance of creek centerline. The process of identifying this critical mass ratio can help growing cities find a balance between the need to encourage development in designated areas and the need to protect natural creek systems everywhere. I recommend that municipalities review the effects of reducing drainage area threshold for each watershed, and then identify the drainage area threshold that, when protected by setback requirements, allows for extended and connected greenways as well as an increase in density. / text

My dissertation is based on a unified self-consistent scaling framework which is consistent with key behavior exhibited by many spatially/temporally varying earth, environmental and other variables. This behavior includes tendency of increments to have symmetric, non-Gaussian frequency distributions characterized by heavy tails that often decay with lag; power-law scaling of sample structure functions (statistical moments of absolute increments) in midranges of lags, with breakdown in power-law scaling at small and/or large lags; linear relationships between log structure functions of successive orders at all lags, also known as extended self-similarity; and nonlinear scaling of structure function power-law exponents with function order. The major question we attempt to answer is: given data measured on a given support scale at various points throughout a 1D/2D/3D sampling domain, which appear to be statistically distributed and to scale in a manner consistent with that scaling framework, what can be said about the spatial statistics and scaling of its extreme values, on arbitrary separation or domain scales? To do so, we limit our investigation in 1D domain for simplicity and generate synthetic signals as samples from 1D sub-Gaussian random fields subordinated to truncated monofractal fractional Brownian motion (tfBm) or truncated fractional Gaussian noise (tfGn). Such sub-Gaussian fields are scale mixtures of stationary Gaussian fields with random variances that we model as being log-normal or Lévy α/2-stable. This novel interpretation of the data allows us to obtain maximum likelihood estimates of all parameters characterizing the underlying truncated sub-Gaussian fields. Based on synthetic data, we find these samples conform to the aforementioned scaling framework and confirm the effectiveness of generation schemes. We numerically investigate the manner in which variables, which scale according to the above scaling framework, behave at the tails of their distributions. Ours is the first study to explore the statistical scaling of extreme values, specifically peaks over thresholds or POTs, associated with such families of sub-Gaussian fields. Before closing this work, we apply and verify our analysis by investigating the scaling of statistics characterizing vertical increments in neutron porosity data, and POTs in absolute increments, from six deep boreholes in three different depositional environments.

This is an in-depth study of word knowledge where the researcher attempts to investigate the need to systematically teach vocabulary in the language classroom. It is motivated by findings within second language (L2) vocabulary testing research that state that the current communicative language learning environment is insufficient for L2 learners to acquire adequate vocabulary knowledge and L2 learners need help with vocabulary learning (Laufer, 2005). This semester-long study explores the need to provide explicit vocabulary instruction from within a meaningful environment. It also investigates the relevance of focus on forms and focus on form practices in helping second language (L2) learners increase the size and depth of word knowledge. The study involved 129 undergraduates from a writing program, and used a pretest and posttest design to measure gains in L2 learners vocabulary knowledge. .The results indicate that the vocabulary gains for both implicit (control) and explicit (treatment) instructional context were not very different though the subjects in the implicit instructional group learned slightly more words compared to the explicit instructional group. However, this has more to do with individual instructor effectiveness and learner proficiency. In terms of word use, L2 learners subjected to explicit focus on forms and focus on form tasks increased their word use while the first language (L1) learners and L2 learners from the control groups did not increase their academic words. Therefore, it is possible to suggest that L2 learners can be taught to increase the depth of their vocabulary knowledge through explicit instructional practices. In terms of L1 and L2 learners, the initial findings revealed that the L2 learners did not benefit from explicit instruction. However, additional analysis revealed that subjects with sufficient vocabulary knowledge at the 2000 word level can increase their word size much more rapidly than the proficient L2 learners in the control group. An additional test on L1 and L2 learners' word collocation skills indicated that while explicit instruction did not help increase L2 learners vocabulary size, it was able to help L2 learners increase their word collocation skills and also make word associations that are closer to L1 learners' associations.

We have effectively identified and removed ground roll through a twostep process. The first step is to identify the major components of the ground roll through various methods including multiscale separation, directional or frequency filtering or by any other method that identifies the ground roll. Given this estimate for ground roll, the recorded signal is separated during the second step through a block-coordinate relaxation method that seeks the sparsest set for weighted curvelet coefficients of the ground roll and the sought-after reflectivity. The combination of these two methods allows us to separate out the ground roll signal while preserving the reflector information. Since our method is iterative, we have control of the separation process. We successfully tested our algorithm on a real data set with a complex ground roll and reflector structure.