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Responses to fertilizer nitrogen of rangelands at various elevations in the southern interior of British ColumbiaHall, Kenneth M. January 1971 (has links)
Nitrogen fertilization of grassland and forest range in British Columbia is examined as a practical means of increasing productivity. Trials were undertaken at several altitudes and responses were studied in fenced and unfenced plots over a period of two years. Four clipping times, three rates of ammonium nitrate application and two times of application were the major treatments at most sites. Information on climate and soil was also obtained and clipped forage was analyzed for nitrogen.
Increases in dry matter yield and combined nitrogen levels obtained on all sites despite the marked mid-season limitation of soil moisture; responses to autumn fertilization were evident in early growth in the spring following application; responses to spring application were delayed. Response to fertilizer has continued to be marked in the second year after application. Understory vegetation of the forest range responded to fertilization at first but by the second year, it appears, overstory vegetation (trees) was responding to the detriment of understory yield. / Land and Food Systems, Faculty of / Graduate
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Variable-Complexity Approximations for Aerodynamic Parameters in Hsct OptimizationGolovidov, Oleg 18 June 1997 (has links)
A procedure for generating and using polynomial approximations to the range or to the cruise drag components in terms of 29 design variables for the High Speed Civil Transport (HSCT) configuration and performance design is presented. Response surface model methodology is used to fit quadratic polynomials to data gathered from a series of numerical analyses of different HSCT designs. Several techniques are employed to minimize the number of required analyses and to maintain accuracy. Approximate analysis techniques are used to find regions of the design space where reasonable HSCT designs could occur and response surface models are built using higher fidelity analysis results of the designs in this "reasonable" region. Regression analysis and analysis of variance are then used to reduce the number of polynomial terms in the response surface model functions. Optimizations of the HSCT are then carried out both with and without the response surface models, and the effect of the use of the response surface models is discussed. Results of the work showed that considerable reduction of the amount of numerical noise in optimization is achieved with response surface models and the convergence rate was slightly improved. Careful attention was required to keep the accuracy of the models at an acceptable level.
NOTE: (07/2012) An updated copy of this ETD was added after there were patron reports of problems with the file. / Master of Science
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INVESTIGATION OF THE POTENTIAL FOR FORAGE SPECIES TO ENHANCE THE SUSTAINABILITY OF DEGRADED RANGELAND AND CROPLAND SOILSNkombe, Boniphace Mokiri January 2016 (has links)
No description available.
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Extraction of 3D Object Representations from a Single Range ImageTaha, Hussein Saad 28 January 2000 (has links)
The main goal of this research is the automatic construction of a computer model of 3D solid objects from a single range image. This research has many real world applications, including robotic environments and the inspection of industry parts. The most common methods for 3D-object extraction are based on stereo reconstruction and structured light analysis. The first approach encounters the difficulty of finding a correspondence of points between two images for the same scene, which involves intensive computations. The latter, on the other hand, has limitations and difficulties in object extraction, namely, inferring information about 3D objects from a 2D image. In addition, research in 3D-object extraction up to this point has lacked a thorough treatment of overlapped (occluded) objects.
This research has resulted in a system that can extract multiple polyhedral objects from a single range image. The system consists of several parts: edge detection, segmentation, initial vertex extraction, occlusion detection, grouping faces into objects, and object representation. The problem is difficult especially when occluded objects are present. The system that has been developed separates occluded objects by combining evidence of several types.
In the edge detection algorithm, noise reduction for range images is treated first by implementing a statistically robust technique based on the least median of squares. Three approaches to edge detection are presented. One that detects change in gradient orientation is a novel approach, which is implemented in the algorithm due to its superior performance, and the other two are extensions of work by other researchers. In general, the performance of these edge detection methods is considerably better than many others in the domain of range image segmentation.
A hybrid approach (region-edge based) is introduced to achieve a robust solution for a single range image segmentation. The segmentation process depends on collaborating edge and region techniques where they give complementary information about the scene. Region boundaries are improved using iterative refinement.
A novel approach for initial vertex extraction is presented to find the vertices of the polyhedral objects. The 3D vertex locations for the objects are obtained through an analysis of two-dimensional (2D) region shape and corner proximity, and the vertices of the polyhedra are extracted from the individual faces.
There are two major approaches for dealing with occlusion. The first is an automatic identification of layers of 3D solid objects within a single range image. In this novel approach, a histogram of the distance values from a given range image is clustered into separate modes. Ideally, each mode of the histogram will be associated with one or more surfaces having approximately the same distance from the sensor. This approach works well when the objects are lying at different distances from the sensor, but when two or more objects are overlapped and lying at the same distance from the sensor, this approach has difficulty in detecting occlusion.
The second approach for occlusion detection is considered the major contribution of this work. It detects occlusion of 3D solid objects from a single range image using multiple sources of evidence. This technique is based on detecting occlusion that may be present between each pair of adjacent faces associated with the estimated vertices of the 3D objects. This approach is not based on vertex and line labeling as other approaches are; it utilizes the topology and geometrical information of the 3D objects.
After occlusion detection, faces are grouped into objects according to their adjacency relations and the absence or presence of occlusion between them. The initial vertex estimates are improved significantly through a global optimization procedure. Finally, models of the 3D objects are represented using the boundary representation technique that makes use of the region adjacency graph (RAG) paradigm.
The experimental results of this research were obtained using real range images obtained from the CESAR lab at Oak Ridge National Laboratory. These images were obtained using a Perceptron laser range finder. These images contain single and multiple polyhedral objects, and they have a size of 512x512 pixels and a quantization of 12 bits per pixel.
A quantitative evaluation of the construction algorithms is given. Part of this evaluation depends on the comparison between the results of the proposed segmentation technique and the ground truth database for these range images. The other part is to compare the results of the implemented algorithms with the results of other researchers, and it is found that the system developed here exhibits better performance in terms of the accuracy of the boundaries for the regions of the segmented images. A subjective comparison of the new edge detection methods with some traditional approaches is also provided for the set of range images. An evaluation of the new approach to occlusion detection is also presented.
A recommendation for future work is to extend this system to involve images contain objects with curved surfaces. With some modifications to the multiple evidence-based approach of occlusion detection, the curved objects could be addressed. In addition, the model could be updated to include representation of the hidden surfaces for the 3D objects. This could be achieved by using multiple views for the same scene, or through assumptions such as symmetry to infer the shape of the hidden portion of the objects. / Ph. D.
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Home range dynamics of black bears in the Alleghany Mountains of western VirginiaOlfenbuttel, Colleen 21 October 2005 (has links)
The Cooperative Alleghany Bear Study (CABS) was initiated in 1994 to address concerns over the lack of biological and ecological data for black bear (Ursus americanus) populations in the Alleghany Mountains of western Virginia. I examined home range dynamics of bears during 1994-2002 on 2 study areas that were approximately 160 km apart. I analyzed my data with 3 home range programs (AMA, HRE, and ABODE) and determined the HRE was the least biased and produced the most biologically reasonable home range estimates. I used HRE to generate annual home ranges (fixed-kernel) for 90 bears over 160 bear years; I also generated seasonal home ranges using MCP. Annual and seasonal home ranges of male and female adult bears in the southern study area were larger than that of male and female adult bears in the northern study area, respectively; southern females and northern males had annual home ranges similar in size at the 95% and 75% fixed-kernel contours. In both study areas, most bears did not shift their range when transitioning from spring to summer (North: 63.0%; South: 57.0%) or from summer to fall (North: 67.0%; South: 65.0%), while most bears shifted their seasonal range between spring and fall (North: 67.0%; South: 52.0%). Most female bears in both study areas maintained the same spring and summer home range throughout the duration of the study, while 63% of northern females changed their fall home range and 55% of southern females maintained their fall home range. I found no differences in annual and seasonal home range size among years or among age classes for adult females, but tests for intra-year seasonal difference indicated that fall range was larger than spring and summer in 1997, when western Virginia experienced a poor mast crop. Females with and without COY had similar annual home ranges in either study area. In the north, seasonal home range size did not differ between females with and without COY, while in the south, breeding females (i.e. without COY) had larger spring ranges and smaller fall ranges than females with COY. In both study areas, females with COY had larger fall home ranges than during spring, while seasonal ranges of breeding females did not vary in size during the year. / Master of Science
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Trickle-down ecohydrology : complexity of rainfall interception and net precipitation under forest canopiesAllen, Scott T. (Scott Thomas) 12 June 2012 (has links)
Rainfall interception is a primary control over the moisture input to a forested ecosystem through the partitioning of precipitation into throughfall, stemflow, and an evaporated component (i.e. the interception loss). Rainfall interception is a spatially and temporally varying process at multiple scales, but heterogeneity in interception processes are poorly understood and poorly described in the literature. We need to know how net precipitation varies in ecosystems because natural systems are driven by non-linear ecohydrological processes where mean values cannot capture localized effects or the cumulative consequences associated with an extremely heterogeneous input. In this thesis, we present two studies that investigate the heterogeneity of interception loss and throughfall in a forested catchment in the western Cascades range of Oregon. In one study, we examined the spatio-temporal patterns among point measurements of throughfall depth and isotopic composition to determine the cause of isotopic differences between throughfall and rainfall. Our results indicated that the residual moisture retained on the canopy from previous events plays a major role in determining the isotopic composition of the next event's throughfall. Differences between the isotopic composition of throughfall samples could indicate further partitioning of throughfall into various flow-paths from the canopy. The second project examined the question of how vegetation variability and terrain complexity drive interception loss heterogeneity at the whole-catchment scale. We applied a simple interception model to a watershed gridded at a 50 m resolution to investigate the relative importance of topographic and vegetative controls over the spatial variability of interception loss. We found that storm characteristics are crucial regarding the impact of spatial heterogeneities in vegetation and evaporation rates. In the Pacific Northwest climate, interception loss is not highly variable for the majority of the year because the annual precipitation is dominated by large storms with low interception losses. However, the net precipitation input to a watershed becomes extremely heterogeneous in the summer due to high interception loss variability. Summer interception loss could be an important control over the spatial variability of the availability of moisture, coinciding with when vegetation is most water-limited. / Graduation date: 2013
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GUARANTEED QUALITYOF SERVICE INTERNETWORKING FOR INTEGRATING DISTRIBUTED INTERACTIVE SIMULATIONS WITH THE TELEMETRY RANGERucinski, Gary 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1994 / Town & Country Hotel and Conference Center, San Diego, California / In recent years the extension of interactive simulation technology to involve
simulators and live vehicles from geographically dispersed sites has produced a
demand for high-bandwidth communication networks that can provide guaranteed
quality of service (e.g., insured availability of bandwidth and upper bounds on
end-to-end delay). This paper reviews the requirements distributed interactive
simulation places on the communications infrastructure and describes the Defense
Simulation Internet (DSI), a network developed by the Advanced Research Projects
Agency to support distributed interactive simulations. Key features of the DSI are:
more than 120 participating sites spanning Europe, the United States and Asia; use of
a resource reservation mechanism to provide guaranteed quality of service; and
support for communication between classified sites. Furthermore, the paper describes
the internetworking protocols used in the DSI to provide guaranteed quality of service
and to support transmission of classified communications. Other topics discussed in
the paper are research efforts that anticipate increased load on the DSI and the
relevance of the technology to the integration of the telemetry range and distributed
interactive simulations.
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A Global Conservation Assessment of Temperate Forests: Status and ProtectionGagnon, Jennifer 19 December 2003 (has links)
Global biodiversity protection requires the development of protected areas that include representative samples of different ecosystems and their associated biodiversity (Dudley 1992, Scott et al. 2001a). I compared long-term decline and protection of forests in three major biomes; boreal, temperate and tropical. I found that forests in the temperate biome are less abundant and less protected than forests in the boreal and tropical biomes. I conducted regional analyses for five continents on the degree of protection of temperate forests across naturally occurring geographic and elevational ranges. My results indicate that protected temperate forests do not represent the full geographic and elevational range of naturally occurring temperate forests. Bias in location, elevation and slope of protected areas are present at both the regional and global scale. Better protection of temperate forests is needed if the diversity and resources associated with these forests types across their geographic range is to be preserved.
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Relationships of green-tree retention following timber harvest to forest growth and species composition in the western Cascade MountainsRose, Coulter R. 18 November 1993 (has links)
National Forest management in the Pacific Northwest is shifting
from a focus on commodity production to ecosystem management, in which
the health of the entire forest ecosystem is considered, rather than that
of a few key species. Ecosystem management includes retention of some
live trees following timber harvest (green-tree retention) to preserve
biodiversity, imitating the natural fire regime of large, but patchy
fires that leave many live trees. How ecosystem management will affect
growth and species composition of future forests is an important
question. This study takes a retrospective approach to this question by
using past disturbance as an analogue to green-tree retention following
timber harvest. Using USDA Forest Service timber inventory plot data
from the Cascade Mountains of Oregon and SW Washington, 132 unmanaged
stands were identified with a tree cohort of 70-110 years old
(regeneration) or a tree cohort of 70-110 years old with an overstory of
large trees 200+ years old (remnants). All stands were in the Tsuga
heterophylla (Raf.) Sarg. zone (Franklin and Dyrness 1973). Single-aged
stands represented clearcuts, while two-aged stands served as analogues
to stands harvested with green-tree retention. Regeneration basal
area/hectare (ba/ha) declined when remnant-tree densities exceeded about
15 remnant trees/ha (R��=0.51) in a relationship roughly described by a
sigmoidal curve. Conceptually removing remnant-tree space occupancy
effects decreased remnant-tree density's value as a predictor of
regeneration ba/ha by about 50% at management-level remnant densities
(���45 remnant trees/ha). Thus, it appears that remnant "effects" were a
result of both remnant-tree space occupancy and remnant resource use.
Douglas-fir ba/ha in the regeneration also declined when remnant-tree
densities exceeded about 15 remnant trees/ha (R��=0.60). Western hemlock
ba/ha in the regeneration increased slightly with increasing remnant-tree
densities (R��=0.19). Western redcedar ba/ha in the regeneration was
apparently not related to remnant-tree density (R��=0.02). The degree of
aggregation in remnant trees did not appear to affect regeneration ba/ha,
but few stands contained the isolated clumps of remnant trees likely
under a management scenario. Neither measured site characteristics nor
regeneration density was related to regeneration ba/ha across species.
Remnant-tree density was apparently unrelated to tree-species diversity
in the regeneration. Total-stand ba/ha remained relatively constant
across remnant densities. / Graduation date: 1994
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Coast Range Ophiolite near Stonyford, Northern California : evidence for normal faultingHoag, Scott Henry 20 July 2012 (has links)
The Franciscan Complex and Coast Range Ophiolite (CRO) are juxtaposed along the Coast Range Fault (CRF), which is steeply dipping to near vertical in the Stonyford area. The CRF has been interpreted as a thrust fault and a normal fault but no kinematic data has been presented for the Stonyford region.
The CRO locally is internally disrupted and can be described as an ophiolitic mélange. Near Stonyford, serpentinites are in contact with Great Valley sediments to the east and with Franciscan rocks to the west. Mafic volcanics are only found at a few localities with some chert and gabbros. Massive serpentinites form most of the southernmost transect while foliated serpentinite mélange dominates the northern transects.
Six structural geologic transects were made in the CRO along National Forest Service roads in the Mendocino National Forest near the Stonyford, California area. Data were collected from 21 road cuts totaling approximately 10 kilometers of CRO exposure. Exposures were typically two meters high with the main exception along Goat Mountain Road where the serpentinite was massive with outcrop heights of 10 to 20 meters. Fault plane orientations and sense of slip (where recognizable) were measured for all faults traceable for more than 10 cm. A total of 1,108 faults were measured, 414 contained lineations, and 326 had lineations with steps which determine sense of slip. Approximately two-thirds of the faults with full kinematics had evidence for normal offset. About 25% recorded reverse offset, mostly steeply dipping surfaces. Strike-slip faulting, both right and left-lateral, accounted for 10% of the data.
The ascent of the Franciscan and CRO, and upturning of the Knoxville Formation (Great Valley Group) to near vertical attitude was mostly a result of normal faulting. The Great Valley Group strata, with little internal offset by faulting, indicates the disruption of the CRO near Stonyford predates most of the normal faulting. This is consistent with pre-subduction deformation of the CRO in an oceanic fracture zone. / text
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