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The design, development and evaluation of an active stereoscopic telepresence systemAsbery, Richard January 1997 (has links)
The work presented in this thesis documents the design, development and evaluation of a high performance stereoscopic telepresence system. Such a system offers the ability to enhance the operator perception of a remote and potentially hazardous environment as an aid to performing a remote task. To achieve this sensation of presence demands the design of a highly responsive remote camera system. A high performance stereo platform has been designed which utilises state- of-the-art cameras, servo drives and gearboxes. It possesses four degrees of freedom; pan, elevation and two camera vergence motions, all of which are controlled simultaneously in real-time by an open architecture controller. This has been developed on a PC/AT bus architecture and utilises a PID control regime. The controller can be easily interfaced to a range of input devices such as electromagnetic head tracking systems which provide the trajectory data for controlling the remote mechatronic platform. Experiments have been performed to evaluate both the mechatronic system and operator oriented performance aspects of the telepresence system. The mechatronic system investigations identify the overall system latency to be 80ms, which is considerably less than other current systems. The operator oriented evaluation demonstrates the necessity for a head tracked telepresence system with a head mounted display system. The need for a low latency period to achieve high operator performance and comfort during certain tasks is also established. This is evident during trajectory following experiments where the operator is required to track a highly dynamic target. The telepresence system has been fully evaluated and demonstrated to enhance operator spatial perception via a sensation of visual immersion in the remote environment.
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Complex Effects of Human-Impacted Landscapes on the Spatial Patterns of Mammalian CarnivoresHeim, Nicole Alexis 01 May 2015 (has links)
In the face of an expanding global human footprint, mammalian carnivores have become vulnerable to the effects of large-scale landscape change. Throughout North America, wide-ranging terrestrial carnivores have experienced significant species declines and range retractions. Understanding the complex and interacting effects of human-caused habitat disturbance on highly mobile species remains an ongoing challenge for ecologists. To address these challenges, studies commonly select a focal species to examine the adverse effects of human disturbance. Due to the paucity of multi-species study, little is yet known about the relative role interspecific interactions play within communities of carnivores in human-altered systems. In an effort to address this knowledge gap, I examined occurrence patterns of one species known to be sensitive to human disturbance – the wolverine – and compared occurrence patterns among multiple carnivores across a gradient of increasing human land use within a rugged and heterogeneous landscape in the Canadian Rocky Mountains of Alberta.
I surveyed carnivore occurrence by combining remote camera trapping and non-invasive genetic tagging. Using a systematic grid based design, medium to large sized carnivores were detected over an area approximately 15,000km2. Consistent with the literature, I found wolverines to be less likely to occur outside of protected areas boundaries and with increasing human-caused landscape disturbance. Contrary to recent climate-focused hypotheses, the spatial pattern of wolverine occurrence was best explained by cumulative effects. When modeling multiple carnivore occurrence across this spatial gradient of human land use, no generality in response was observed. However, a consistent and distinct dissimilarity in response to natural and anthropogenic landscape features was found between wolverine and coyote.
The patterns of occurrence led me to infer that habitat condition in the more human-altered systems found along eastern slopes of the Canadian Rocky Mountains is less suitable for some more sensitive species and benefits more human-adapted species. I further hypothesized that an indirect and additive effect of human disturbance is increased interspecific competition between co-occurring carnivores that differentially respond to changes in habitat condition. My results emphasize that by broadening our scope to investigate both single and multiple species, ecologists and managers may better understand the full suite of factors influencing current and future distribution patterns. / Graduate / heimnikki@gmail.com
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Pygmy Rabbit (Brachylagus idahoensis) Habitat Use, Activity Patterns and Conservation in Relationship to Habitat TreatmentsLee, Janet E. 27 June 2008 (has links) (PDF)
This study examined activity patterns and habitat use of pygmy rabbits (Brachylagus idahoensis) in mechanically treated and untreated areas in south-central Utah 2005-2008. We monitored fecal pellet plots in continuous sagebrush habitat as well as along treatment edges to record deposition and leporid presence over timed periods. Pygmy rabbit use of big sagebrush was higher than black-tailed jackrabbits (Lepus californicus) and mountain cottontail rabbits (Sylvilagus nuttallii ) (P< 0.01) relative to treated areas (P <0.01). We also compared pygmy rabbit use of areas with continuous sagebrush to residual sagebrush in a sample of mechanically treated areas. Our results suggest a treatment effect with higher (P <0.01) average counts of pygmy rabbit pellets in areas with continuous sagebrush compared to sagebrush strips and islands within treated areas. Before the big sagebrush biotype inhabited by pygmy rabbits is treated to reduce the occurrence and dominance of big sagebrush, we recommend managers consider two options. The first is no treatment, thus preserving, as is, the critical habitat of the pygmy rabbit and other sympatric big sagebrush obligate species of wildlife. The second option cautiously introduces the first prescription of habitat treatment ever recommended in relationship to the pygmy rabbit. This prescription includes recommended widths of the treated areas, seed mixes, widths of the preserved intact big sagebrush habitat for pygmy rabbits as well as suggested grazing systems for domestic livestock. Activity patterns of pygmy rabbits at their burrow were documented through the use of remote cameras. Photographs were analyzed for temporal and seasonal patterns of activity. Our results suggested that time of day was important in the activity level of pygmy rabbits while season was not. Pygmy rabbits were active during all time periods of the day but the greatest levels of activity occurred at night. Numerous other wildlife species were recorded by our remote cameras including other species of leporids, birds, rodents, reptiles and terrestrial predators.
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Space Use and Annual Survival of Hybridized Mouflon Sheep in Hawaii and Comparing Estimates of Population Size through Instantaneous Sampling and Photographic Capture-RecaptureAdams, Bradley Jay 01 April 2019 (has links)
Significant efforts in conservation are devoted to the management and study of ungulates, due to their significant roles in ecosystems as well as their potential economic value. This is especially true for species considered exotic, such as mouflon sheep (Ovis musimon) in Hawaii. Effective management of an exotic species requires an understanding of ecological metrics such as space use, survival, and population size. We provided these metrics for a population of mouflon that have hybridized with feral sheep (Ovis aries) on the island of Hawaii. In Chapter 1, we quantified space use and annual survival of sheep in an area where sheep are managed for hunting opportunity. We determined that sheep have relatively small home-ranges and high rates of annual survival (>90%). In Chapter 2, we provided the first estimate of population size for the same study area while simultaneously testing the viability of a novel method of estimating population size, currently known as Instantaneous Sampling. Using photographic capture recapture as a comparison method, we compared estimates derived from both techniques and provided support for Instantaneous Sampling as an alternative method for estimating population size.
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Automated video-based measurement of eye closure using a remote camera for detecting drowsiness and behavioural microsleepsMalla, Amol Man January 2008 (has links)
A device capable of continuously monitoring an individual’s levels of alertness in real-time is highly desirable for preventing drowsiness and lapse related accidents. This thesis presents the development of a non-intrusive and light-insensitive video-based system that uses computer-vision methods to localize face, eyes, and eyelids positions to measure level of eye closure within an image, which, in turn, can be used to identify visible facial signs associated with drowsiness and behavioural microsleeps.
The system was developed to be non-intrusive and light-insensitive to make it practical and end-user compliant. To non-intrusively monitor the subject without constraining their movement, the video was collected by placing a camera, a near-infrared (NIR) illumination source, and an NIR-pass optical filter at an eye-to-camera distance of 60 cm from the subject. The NIR-illumination source and filter make the system insensitive to lighting conditions, allowing it to operate in both ambient light and complete darkness without visually distracting the subject.
To determine the image characteristics and to quantitatively evaluate the developed methods, reference videos of nine subjects were recorded under four different lighting conditions with the subjects exhibiting several levels of eye closure, head orientations, and eye gaze. For each subject, a set of 66 frontal face reference images was selected and manually annotated with multiple face and eye features.
The eye-closure measurement system was developed using a top-down passive feature-detection approach, in which the face region of interest (fROI), eye regions of interests (eROIs), eyes, and eyelid positions were sequentially localized. The fROI was localized using an existing Haar-object detection algorithm. In addition, a Kalman filter was used to stabilize and track the fROI in the video. The left and the right eROIs were localized by scaling the fROI with corresponding proportional anthropometric constants. The position of an eye within each eROI was detected by applying a template-matching method in which a pre-formed eye-template image was cross-correlated with the sub-images derived from the eROI. Once the eye position was determined, the positions of the upper and lower eyelids were detected using a vertical integral-projection of the eROI. The detected positions of the eyelids were then used to measure eye closure.
The detection of fROI and eROI was very reliable for frontal-face images, which was considered sufficient for an alertness monitoring system as subjects are most likely facing straight ahead when they are drowsy or about to have microsleep. Estimation of the y- coordinates of the eye, upper eyelid, and lower eyelid positions showed average median errors of 1.7, 1.4, and 2.1 pixels and average 90th percentile (worst-case) errors of 3.2, 2.7, and 6.9 pixels, respectively (1 pixel 1.3 mm in reference images). The average height of a fully open eye in the reference database was 14.2 pixels. The average median and 90th percentile errors of the eye and eyelid detection methods were reasonably low except for the 90th percentile error of the lower eyelid detection method. Poor estimation of the lower eyelid was the primary limitation for accurate eye-closure measurement.
The median error of fractional eye-closure (EC) estimation (i.e., the ratio of closed portions of an eye to average height when the eye is fully open) was 0.15, which was sufficient to distinguish between the eyes being fully open, half closed, or fully closed. However, compounding errors in the facial-feature detection methods resulted in a 90th percentile EC estimation error of 0.42, which was too high to reliably determine extent of eye-closure. The eye-closure measurement system was relatively robust to variation in facial-features except for spectacles, for which reflections can saturate much of the eye-image. Therefore, in its current state, the eye-closure measurement system requires further development before it could be used with confidence for monitoring drowsiness and detecting microsleeps.
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The Influence of Anthropogenic Development of Water on Coyotes and Kit Foxes in the Great Basin and Mojave DesertsHall, Lucas Keith 13 March 2013 (has links) (PDF)
Anthropogenic provisioning of water (water developments) to enhance abundance and distribution of wildlife is a common management practice in arid regions where water is limiting. Despite the long-term and widespread use of water developments, little is known about how they influence distribution, competition dynamics, and behavior of native species. To elucidate the potential influences of water developments on native species, we tested hypotheses concerning the occurrence and behavior of native kit foxes (Vulpes macrotis). First, we tested the indirect effect of water hypothesis (IEWH) which proposes that water developments negatively affect the arid-adapted kit fox by enabling a water-dependent competitor (i.e., coyote; Canis latrans) to expand distribution in arid landscapes. We tested the two predictions of the IEWH (i.e., coyotes will visit areas with water more frequently and kit foxes will avoid coyotes) and evaluated relative use of water by canids in the Great Basin and Mojave Deserts from 2010 to 2012. We established scent stations in areas with (wet) and without (dry) water and monitored visitation by canids to scent stations and water sources using infrared-triggered cameras. There was no difference in the proportions of visits to scent stations in wet or dry areas by coyotes or kit foxes at either study area. There was no correlation between visits to scent stations by coyotes and kit foxes. Visitation to water sources was not different for coyotes between study areas, but kit foxes visited water sources more in Mojave than Great Basin. The intense visitation to water by kit foxes in Mojave challenges our understanding that this species does not readily drink water. Our results did not support the IEWH in the Great Basin or Mojave Deserts for these two canids. Second, we tested three hypotheses that have been proposed to explain spatial variation in vigilance behavior. The predator-vigilance hypothesis (PVH) proposes that prey increase vigilance where there is evidence of predators. The visibility-vigilance hypothesis (VVH) suggests that prey increase vigilance where detection of predators is impeded or visibility is obstructed. The refuge-vigilance hypothesis (RVH) proposes that prey may perceive areas with low visibility (greater cover) as refuges and decrease vigilance. We evaluated support for these hypotheses using the kit fox, a solitary carnivore subject to intraguild predation, as a model. From 2010 to 2012, we used infrared-triggered cameras to record video of kit fox behavior at water developments in the Mojave Desert. The RVH explained more variation in vigilance behavior of kit foxes than the other two hypotheses (AICc model weight = 0.37). Kit foxes were less vigilant at water developments with low overhead cover (refuge) obstructing visibility. Based on our results, the PVH and VVH may not be applicable to all species of prey. Solitary prey, unlike gregarious prey, may use areas with concealing cover to maximize resource acquisition and minimize vigilance.
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Summer Watering Patterns of Mule Deer and Differential Use of Water by Bighorn Sheep, Elk, Mule Deer, and Pronghorn in UtahShields, Andrew V. 06 December 2012 (has links) (PDF)
Changes in the abundance and distribution of free (drinking) water can influence wildlife in arid regions. In the western USA, free water is considered by wildlife managers to be important for bighorn sheep (Ovis canadensis), elk (Cervus elaphus), mule deer (Odocoileus hemionus), and pronghorn (Antilocapra americana). Nonetheless, we lack information on the influence of habitat and landscape features surrounding water sources, including wildlife water developments, and how these features may influence use of water by sexes differently. Consequently, a better understanding of differential use of water by the sexes could influence the conservation and management of those ungulates and water resources in their habitats. We deployed remote cameras at water sources to document water source use. For mule deer specifically, we monitored all known water sources on one mountain range in western Utah, during summer from 2007 to 2011 to document frequency and timing of water use, number of water sources used by males and females, and to estimate population size from individually identified mule deer. Male and female mule deer used different water sources but visited that resource at similar frequencies. On average, mule deer used 1.4 water sources and changed water sources once per summer. Additionally, most wildlife water developments were used by both sexes. We also randomly sampled 231 water sources with remote cameras in a clustered-sampling design throughout Utah in 2006 and from 2009 to 2011. In association with camera sampling at water sources, we measured several site and landscape scale features around each water source to identify patterns in ungulate use informative for managers. We used model selection to identify features surrounding water sources that were related to visitation rates for male and female bighorn sheep, elk, mule deer, and pronghorn. Top models for each species were different, but supported models for males and females of the same species generally included similar covariates, although with varying strengths. Our results highlight the differing use of water sources by the sexes. This information will help guide managers when siting and reprovisioning wildlife water developments meant to benefit those species, and when prioritizing natural water sources for preservation or enhancement.
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Using Remote Cameras to Estimate the Abundance of UngulatesTaylor, Jace C 01 December 2017 (has links)
Many wildlife populations globally are experiencing unprecedented declines, and without accurate and precise estimates of abundance, we will not be able to conserve these vulnerable species. Remote cameras have rapidly advanced as wildlife monitoring tools and may provide accurate and precise estimates of abundance that improve upon traditional methods. Using remote cameras to estimate abundance may be less expensive, less intrusive, less dangerous, and less time consuming than other methods. While it is apparent that remote cameras have a place in the future of wildlife monitoring, research, and management, many questions remain concerning the proper use of these tools. In an effort to answer some of these questions, we used remote cameras to study a population of Rocky Mountain bighorn sheep (Ovis canadensis) in Utah, USA from 2012 to 2014. In Chapter 1, we compared methods using remote cameras against 2 traditional methods of estimating abundance. In Chapter 2, we evaluated the relationship between deployment time of cameras and proportion of photos needed to be analyzed to obtain precise estimates of abundance. We found that methods using remote cameras compared favorably to traditional methods of estimating abundance, and provided a number of valuable advantages. In addition, we found that remote cameras can produce precise estimates of abundance in a relatively short sampling period. Finally, we identified the optimal sampling period to produce precise estimates of abundance for our study population. Our findings can help researchers better utilize the potential of remote cameras, making them a more suitable alternative to traditional wildlife monitoring.
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Using Remote Cameras to Estimate the Abundance of UngulatesTaylor, Jace C 01 December 2017 (has links)
Many wildlife populations globally are experiencing unprecedented declines, and without accurate and precise estimates of abundance, we will not be able to conserve these vulnerable species. Remote cameras have rapidly advanced as wildlife monitoring tools and may provide accurate and precise estimates of abundance that improve upon traditional methods. Using remote cameras to estimate abundance may be less expensive, less intrusive, less dangerous, and less time consuming than other methods. While it is apparent that remote cameras have a place in the future of wildlife monitoring, research, and management, many questions remain concerning the proper use of these tools. In an effort to answer some of these questions, we used remote cameras to study a population of Rocky Mountain bighorn sheep (Ovis canadensis) in Utah, USA from 2012 to 2014. In Chapter 1, we compared methods using remote cameras against 2 traditional methods of estimating abundance. In Chapter 2, we evaluated the relationship between deployment time of cameras and proportion of photos needed to be analyzed to obtain precise estimates of abundance. We found that methods using remote cameras compared favorably to traditional methods of estimating abundance, and provided a number of valuable advantages. In addition, we found that remote cameras can produce precise estimates of abundance in a relatively short sampling period. Finally, we identified the optimal sampling period to produce precise estimates of abundance for our study population. Our findings can help researchers better utilize the potential of remote cameras, making them a more suitable alternative to traditional wildlife monitoring.
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