851 |
A calibration method for MEMS inertial sensors based on optical techniques.January 2008 (has links)
Dong, Zhuxin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references (leaves 77-80). / Abstracts in English and Chinese. / Abstract --- p.ii / 摘要 --- p.iii / Acknowledgements --- p.iv / Table of Contents --- p.v / List of Figures --- p.vii / List of Tables --- p.ix / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Architecture of UDWI --- p.3 / Chapter 1.2 --- Background of IMU Sensor Calibration --- p.5 / Chapter 1.3 --- Organization --- p.7 / Chapter Chapter 2 --- 2D Motion Calibration --- p.10 / Chapter 2.1 --- Experimental Platform --- p.10 / Chapter 2.1.1 --- Transparent Table --- p.10 / Chapter 2.2 --- Matching Algorithm --- p.13 / Chapter 2.2.1 --- Motion Analysis --- p.13 / Chapter 2.2.2 --- Core Algorithm and Matching Criterion --- p.14 / Chapter 2.3 --- Usage of High Speed Camera --- p.17 / Chapter 2.4 --- Functions Realized --- p.17 / Chapter Chapter 3 --- Usage of Camera Calibration --- p.21 / Chapter 3.1 --- Introduction to Camera Calibration --- p.21 / Chapter 3.1.1 --- Related Coordinate Frames --- p.21 / Chapter 3.1.2 --- Pin-Hole Model --- p.24 / Chapter 3.2 --- Calibration for Nonlinear Model --- p.27 / Chapter 3.3 --- Implementation of Process to Calibrate Camera --- p.28 / Chapter 3.3.1 --- Image Capture --- p.28 / Chapter 3.3.2 --- Define World Frame and Extract Corners --- p.28 / Chapter 3.3.3 --- Main Calibration --- p.30 / Chapter 3.4 --- Calibration Results of High Speed Camera --- p.33 / Chapter 3.4.1 --- Lens Selection --- p.33 / Chapter 3.4.2 --- Property of High Speed Camera --- p.34 / Chapter Chapter 4 --- 3D Attitude Calibration --- p.36 / Chapter 4.1 --- The Necessity of Attitude Calibration --- p.36 / Chapter 4.2 --- Stereo Vision and 3D Reconstruction --- p.37 / Chapter 4.2.1 --- Physical Meaning and Mathematical Model Proof --- p.37 / Chapter 4.2.2 --- 3D Point Reconstruction --- p.38 / Chapter 4.3 --- Example of 3D Point Reconstruction --- p.40 / Chapter 4.4 --- Idea of Attitude Calibration --- p.42 / Chapter Chapter 5 --- Experimental Results --- p.45 / Chapter 5.1 --- Calculation of Proportional Parameter --- p.45 / Chapter 5.2 --- Accuracy Test of Stroke Reconstruction --- p.46 / Chapter 5.3 --- Writing Experiments of 26 Letters --- p.47 / Chapter 5.3.1 --- Experimental Results of Letter b --- p.48 / Chapter 5.3.2 --- Experimental Results of Letter n with ZVC --- p.51 / Chapter 5.3.3 --- Experimental Results of Letter u --- p.54 / Chapter 5.4 --- Writing of Single Letter s - Multiple Tests --- p.56 / Chapter 5.5 --- Analysis on Resolution Property of Current Vision Algorithm --- p.58 / Chapter 5.5.1 --- Resolution of Current Algorithm --- p.58 / Chapter 5.5.2 --- Tests with Various Filters --- p.59 / Chapter 5.6 --- Calculation of Static Attitude --- p.61 / Chapter Chapter 6 --- Future Work --- p.64 / Chapter 6.1 --- Another Multiple Tests of Letter k --- p.64 / Chapter 6.2 --- Letter Recognition Based on Neural Networks Classification --- p.66 / Chapter Chapter 7 --- Conclusion --- p.69 / Chapter 7.1 --- Calibration ofMAG-μlMU Sensors --- p.69 / Chapter 7.2 --- Calibration of Accelerometers --- p.70 / Chapter 7.3 --- Calibration of Attitude --- p.70 / Chapter 7.4 --- Future Work --- p.71 / Appendix A The Experimental Results of Writing English Letters --- p.72
|
852 |
Form and function of the primate cervical vertebral columnJanuary 2019 (has links)
abstract: As the junction between the head and the trunk, the neck functions in providing head stability during behaviors like feeding to facilitating head mobility during behavior like grooming and predator vigilance. Despite its importance to these vital behaviors, its form and function remain poorly understood. Fossil hominin cervical vertebrae preserve a striking diversity in form despite the commitment to orthograde bipedality. Do these differences in cervical vertebral form correspond to functional variations among our recent ancestors? This dissertation attempts to understand 1) how does the neck function in head stability and mobility 2) how do these functions relate to cervical vertebral form. Kinematic and passive range of motion studies were conducted in several species of primate to obtain measures of function which were subsequently related to skeletal form.
Results show that cervical vertebral morphology does not significantly covary with differences in joint mobility. Rather, they implicate the critical role of ligaments and muscles in facilitating head mobility. Results of the kinematics study show that the neck plays a role in maintaining head stability during locomotion. However, the kinematic data do not significantly correlate with morphological variation among primate species. Given the negative results of the extant morphological analyses, it is difficult to apply them to the fossil record. As such, the functional significance of the disparate morphologies found in the hominin fossil record remain ambiguous. / Dissertation/Thesis / Doctoral Dissertation Anthropology 2019
|
853 |
Small Mammal Diversity, Rattlesnake Demographics, and Resource Utilization in the Great Basin: Implications for Management and Stable Isotope ProxiesHamilton, Bryan T. 01 April 2018 (has links)
Plant carbon isotopes were used to track assimilation of riparian resources by small mammals. Voles and shrews derived significant portions of their carbon from riparian vegetation. Deer and harvest mice were abundant in riparian habitat but assimilated little riparian vegetation indicating that the riparian corridor provided resources other than food. This is first use of stable carbon isotopes to trace riparian resources into a vertebrate community. Conifer encroachment in sagebrush ecosystems negatively affects many wildlife populations. Conifer removal is recommended across millions of hectares in the Great Basin. However the effects of conifer encroachment and conifer removal are unknown for most wildlife species. We show that the consequences of conifer encroachment, a press impact, far outweigh the pulse impact of sagebrush restoration, on small mammal diversity. Lack of demographic data limit the development of effective management, conservation and recovery goals for rattlesnakes. We used a long-term dataset and capture mark recapture models to quantify demography of four rattlesnake populations. Mean population growth indicated an overall stable population across the study, with two of the four sites declining. Survival overwhelmingly contributed to population growth relative to recruitment. No small mammals drank stream water even during periods of environmentally high water stress and high aridity, extension of the linear regression equation for small mammal body water towards the meteoric waterline, captures stream water, the weighted mean average for regional meteoric waters. Similar regression of fossilized small mammal tissues would also capture local meteoric waters. Even in arid regions, small mammal fossils are a suitable proxy for climate reconstructions. In the Great Basin, snowmelt overwhelmingly contributes to local precipitation, plant production, and stream flows. Snowmelt supports riparian and upland plants, and small mammals. Rattlesnakes prey primarily on small mammals, indirectly depending on snow melt for survival and reproduction. Climate models and rattlesnake emergence strongly indicate an earlier onset of spring and reduced ratio of snow to rain. Declining snowpack will have major impacts on biodiversity and management such as riparian vegetation, native plant restoration, trophic interactions, and ecological goods and services.
|
854 |
Modeling the peak absorption of MEH-PPV in various solvents using Density Functional TheoryMoore, Corell H 01 January 2019 (has links)
Density Functional Theory (DFT) and time-dependent Density Functional Theory (TD-DFT) are powerful tools for modeling orbital energy in conjugated molecules and have been useful tools for research in organic photovoltaics. In this work, DFT is first used to explain the red shift in the absorption spectrum and increased absorption observed in MEH-PPV. Initially, the modeling of the red-shift in the absorption peak of MEH-PPV is studied using Gaussian 03 software with the global hybrid functional B3LYP for exchange-correlation and the 6-31G basis set. DFT and TD-DFT are used to separately study the effects of polymer chain length, carbon-carbon double-bond stretching, and the polymer in solution vs. in gas space on red shift in absorption spectrum.
Next, Gaussian 09 software and the same B3LYP functional and 6-31G basis set are used to study interchain and intrachain interactions of MEH-PPV in solution. The red shift in the absorption peaks for three MEH-PPV configurations (single-chain pentamer, two stacked pentamers, and decamer) are compared with experimental results for five different solvents (chloroform, toluene, xylene, dichloromethane, and chlorobenzene). This investigation indicates that inter-chain interactions dominate in “good” aromatic solvents as compared to “poor” non-aromatic solvents. The results suggest that inter-chain charge transfer interactions play a critical role in real solutions and inter-chain aggregation takes precedence over intra-chain aggregation in aromatic solvents.
In the final section of the study, accurate values for the range-separation parameter (w) for three lengths of MEH-PPV polymer (trimer, tetramer, and pentamer) in five different solvents (chloroform, chlorobenzene, xylene, Tetrahydrofuran, and dichloromethane) are reported using the range-separated functionals wB97XD and CAM-B3LYP. Using these data, range separation parameters are predicted and used for longer polymer chains in chloroform solution. The differences in the range separation parameters for the different solvents is statistically significant and gives further insight into the polymer/solvent interaction.
|
855 |
Participant Perceptions of Range Rider Programs Used to Mitigate Wolf-Livestock Conflicts in the Western United StatesParks, Molly 01 August 2015 (has links)
Range Rider Programs (RRPs) are one example of a proactive non-lethal tool that has been implemented in western United States to mitigate gray wolf (Canis lupus) and livestock conflicts. Because RRPs are an emerging non-lethal tool that little is known about, I selected a qualitative research approach to examine participant perceptions to further contemporary understanding of how these efforts are implemented and potential benefits. I surveyed 51 participants from 17 Range Rider Programs (RRPs) in Montana, Washington, and Oregon to determine participant perceptions regarding effectiveness of RRPs as a non-lethal approach to mitigate wolf-conflicts.
I developed a RRPs typology based on information provided by the participants interviewed. The typology identified 3 versions of RRPs programs that revolved around the role of the range rider. These roles included: 1) livestock monitoring, 2) wolf surveillance, and 3) livestock herding. The RRPs, although diverse in operations, shared traits exemplified by community-based conservation programs.
Interview responses suggested a RRP’s primary contribution may not be a direct reduction in livestock depredation by wolves, but instead a collection of indirect technical and socio-political benefits. To improve current RRPs and develop future efforts, programs should be realistic in expectations and the sponsors must work closely with rancher participants to develop an adaptive program that meets their needs, maintains transparent and frequent communication, and provides a forum for feedback.
|
856 |
Factors Influencing Epiphytic Lichen Communities in Aspen-Associated Forests of the Bear River Range, Idaho and UtahRogers, Paul C. 01 May 2007 (has links)
In western North America, quaking aspen (Populus tremuloides Michx.) is the most common hardwood in montane landscapes. Fire suppression, grazing, wildlife management practices, and climate patterns of the past century are some of the threats to aspen coverage in this region. Researchers are concerned that aspen-dependent species may be losing habitat, thereby threatening their long-term local and regional viability. Though lichens have a rich history as air pollution indicators, I believe that they may also be useful as a metric of community diversity associated with habitat change. To date, few studies have specifically examined the status of aspen's epiphytic lichen community in the Rocky Mountains. A preliminary study was conducted using 10 transect-based plots to assess lichen species substrate preferences between aspen and various conifer species and to gain basic knowledge of species diversity. Following this work, I established 47 plots in the Bear River Range of northern Utah and southern Idaho to evaluate the effects of forest succession on epiphytic macrolichen communities. Plots were located in a narrow elevational belt (2,134-2,438 m) to minimize the known covariant effects of elevation and moisture on lichen communities. Results show increasing lichen diversity and a decrease in aspen-dependent species as aspen forests succeed to conifer cover types. The interactive roles of stand aspect, basal area and cover of dominant trees, stand age, aspen bark scars, and recent tree damage were examined in relation to these trends. An aspen index score was developed based on lichens showing an affinity for aspen habitat. I present a landscape-level multivariate analysis of short and long-term factors influencing epiphytic lichen communities in aspen forests. Nonrnetric multidimensional scaling (NMS) ordination stressed the importance of succession and local air pollution sources in shaping lichen communities. I also investigated the role of historic human intrusions and climate on aspen forests and aspen dependent epiphytic lichens at the landscape-level. Implications of this work include 1) realization of nitrogen impacts on ecosystems, 2) the potential for using lichens as bioindicators for monitoring aspen stand health, and 3) suggestions for working with natural disturbance regimes to minimize human impacts on aspen and associated species.
|
857 |
The Ecology of Agropyron Inerme on Protected and Heavily Grazed Range Land in Cache Valley, UtahHanson, Wallace R. 01 May 1939 (has links)
During the past decade much attention has been attracted to the great range lands of the West. The inherently low productivity of these arid lands coupled with abnormal drought and constantly heavy use by livestock because of lack of grazing control, have caused these lands to become greatly depleated over most of the West. That the vegetation on most range land in the intermountain states is depleted appreciably is evident to the careful observer. Undoubtedly the vegetation of much of the range has decreased in quantity, but more serious in many cases is the decrease in quality. Valuable forage species have been replaced by less valuable or even worthless ones. This situation has been recognized by students of range ecology, and, therefore, management plans have been formulated to preserve or improve the forage cover. These plans have undergone changes and are still being modified as basic facts concerning the growth habits of range plants are brought to light. Grazing plans in the past were, of necessity, based upon superficial study and general impressions; plans of the future will be based upon scientific facts supplemented by experience. The studies herein reported were made during the summer of 1938 in southern Cache Valley, Utah. The range under observation is roughly comparable to the northern intermountain grasslands. The observed range occupies the benches and foothills above the more moist valley floor.
|
858 |
The Demography and Determinants of Population Growth in Utah Moose (<i>Alces Alces Shirasi</i>)Ruprecht, Joel S. 01 May 2016 (has links)
Moose in Utah represent the southernmost naturally occurring populations of moose in the world. Concerns over possible numeric declines and a paucity of baseline data on moose in the state prompted the Utah Division of Wildlife Resources to initiate a study of moose demography in collaboration with Utah State University. The objectives of this study were to 1) determine reproductive rates of moose in Utah and the factors which influence them, and 2) combine aerial count data from multiple management units within the state to identify factors which influence interannual variation in population growth rates.
We constructed generalized linear models to relate maternal body condition and age to reproductive success. We found that body condition (P = 0.01) and age (P = 0.02) contributed significantly to the probability of pregnancy and the best model describing this relationship was nonlinear. Body condition also related positively to subsequent calving (P = 0.08) and recruitment (P = 0.05), but model selection suggested the relationship for these metrics was best described by linear models. A meta-analysis of moose reproductive rates in North America suggested that reproductive rates declined significantly with latitude (P ≤ 0.01), i.e. as populations approached their southern range limit.
We used Bayesian state-space models to combine moose count data from different management units to estimate statewide population dynamics between 1958 and 2013. This approach incorporated uncertainty in population counts arising from observation error. Population density and warm winter temperatures negatively influenced population growth rate with a high degree of confidence; 95% Bayesian Credible Intervals for these variables did not overlap zero. Short-term projections of moose abundance in the state suggested that the population will likely remain stable despite projected increases in winter temperature.
Results from this study will aid managers in achieving management objectives as well as future decision making. The unique characteristics of the population also have application toward understanding the dynamics of populations of cold-adapted species at their southern range limit.
|
859 |
Spring and Summer Habitat Preferences of Blue Grouse on the Bear River Range, UtahMaestro, Robert M. 01 May 1971 (has links)
A study of the spring and summer habitat preferences of blue grouse was conducted on the Bear River Range in northern Utah. The main objective was to determine the important factors associated with habitat selection by blue grouse during the breeding season.
One hundred and two sampling areas, delimited by similarities in vegetation and topography, were thoroughly searched with a dog for blue grouse. Fifty-four bio logical and physical variables were measured for each sampling area.
Chi-square tests performed on all variables showed 11 of the 54 variables to be significant at an alpha of 0.20. These 11 variables (li sted below) were considered to be the important factors influencing habitat selection by blue grouse.
(1) search area type
(2) area exposure
(3) elevation
(4) percent forested
(5) understory density
(6) primary cover species
(7) secondary cover species
(8) percent cover maples (Acer grandidentatum)
(9) percent cover mixed brush
(10) percent cover sagebrush (Artemisia tridentata)
(11) total acres
The chi-square test only determined if a variable significantly effected habitat selection by blue grouse. To determine whether this effect was positive or negative, the percent occurrence of areas on which blue grouse were present, or absent, was determined. Results indicated that the most favorable blue grouse habitat was draws at 5,500 -6.499 feet elevation. This favorable habitat contained 1-10 percent cover by maples, or a higher percent of maple which provided a large amount of edge effect; the presence of mixed brush or sagebrush, a medium understory, and an area incline of 5-19 percent.
|
860 |
An Environmental History of the Bear River Range, 1860-1910Hansen, Bradley Paul 01 May 2013 (has links)
The study of environmental history suggests that nature and culture change all the time, but that the rate and scale of such change can vary enormously. During the late 19th and early 20th centuries, Anglo settlement in the American West transformed landscapes and ecologies, creating new and complex environmental problems. This transformation was particularly impressive in Cache Valley, Utah's Bear River Range. From 1860 to 1910, Mormon settlers overused or misused the Bear River Range's lumber, grazing forage, wild game, and water resources and introduced invasive plant and animal species throughout the area. By the turn of the 20th century, broad overuse of natural resources caused rivers originating in the Bear River Range to decline. To address the water shortage, a small group of conservation-minded intellectuals and businessmen in Cache Valley persuaded local stockmen and farmers to support the creation of the Logan Forest Reserve in 1903. From 1903 to1910, forest managers and forest users attempted to restore the utility of the landscape (i.e., bring back forage and improve watershed conditions) however, they quickly discovered that the landscape had changed too much; nature would not cooperate with their human-imposed restoration timelines and desires for greater profit margins. Keeping in mind the impressive rate and scale of environmental decline, this thesis tells the heretofore untold environmental history of the Bear River Range from 1860 to 1910. It engages this history from an ecological and social perspective by (1) exploring how Mormon settlers altered the landscape ecology of the Bear River Range and (2) discussing the reasons why forest managers and forest users failed to quickly restore profitability to the mountain landscape from 1903-1910. As its value, a study of the Bear River Range offers an intimate case study of environmental decline and attempted restoration in the western United States, and is a reminder of how sensitive our mountain ranges really are.
|
Page generated in 0.0505 seconds