916 research outputs found
Vegetation Habitat Mapping of Mammoth Cave National Park Using Multi-date Landsat-8 Imagery and Lidar data
Vegetation habitat mapping can be regarded as a model predicting the geographic distribution of plant cover types from mapped environmental variables. This paper discusses three environmental factors- slope, aspect and bedrock geology that determined different habitat types in Mammoth Cave National Park. The variation of aspect and slope can largely determine the amount of solar radiation and water available to vegetation, which influences the contrasting habitat types formed in a long term. Bedrock geology, one of the most influential factor in the study area, primarily controls the soil types and drainage conditions that support the various habitat types. The habitat model indicated that Acid and Calcareous are the two dominant habitat categories within the Park, which accounted for 46.24% and 49.74% of the total area respectively. The result shows that Calcareous habitats are dispersed throughout the park over limestone bedrock while the most xeric Calcareous habitats are found in the southeast part of the Park. In addition, Acid Xeric and Acid Sub-Xeric habitats are mostly located in the northwest region of the park while the shaded region in the southeast formed mostly Acid Mesic habitat. Calcareous Sub-Mesic habits are moderate mesic habitats over limestone cap-rock. The vegetation habitat modeling result provides critical information for Park’s fire management, for classification of fuel types and for delineation of fire management units
An Augmented Lagrangian Method for the Optimal H
This paper treats the computational method of the optimal H∞ model order reduction (MOR) problem of linear time-invariant (LTI) systems. Optimal solution of MOR problem of LTI systems can be obtained by solving the LMIs feasibility coupling with a rank inequality constraint, which makes the solutions much harder to be obtained. In this paper, we show that the rank inequality constraint can be formulated as a linear rank function equality constraint. Properties of the linear rank function are discussed. We present an iterative algorithm based on augmented Lagrangian method by replacing the rank inequality with the linear rank function. Convergence analysis of the algorithm is given, which is distinct to the now available heuristic methods. Numerical experiments for the MOR problems of continuous LTI system illustrate the practicality of our method
Vegetation Mapping of Mammoth Cave National Park using Multi-date Landsat-8 Imagery and Lidar data
Up-to-date and detailed vegetation map provides critical information for habitat management. In addition, a vegetation map is necessary for the Park’s Fire Management, for classification of fuel types, and for delineation of fire management units. There have been several attempts of vegetation mapping in 1934, 1975 and 1997. Recent advancements in mapping technology and the availability of high resolution Lidar data call for a new vegetation map for the Park’s management team.
In this study, Landsat-8 Operational Land Imager (OLI) imagery, Lidar and geology dataset were applied to vegetation mapping. Habitat types are determined by a combination of geology, aspect and slope. Coniferous and deciduous trees are distinguished using multi-date Landsat-8 imagery through image classification and NDVI analysis. Habitat type and physical properties derived from Lidar data will be applied to identify specific vegetation species.
The research will produce a new vegetation map and a habitat map for the Mammoth Cave National Park. The maps will provide critical information for habitat and fire management. The research method integrating Lidar and Landsat-8 data in digital vegetation and habitat mapping will be valuable for similar projects at other locations
The fundamental gap of a kind of two dimensional sub-elliptic operator
This paper is concerned at the minimization fundamental gap problem for a
class of two-dimensional degenerate sub-elliptic operators. We establish
existence results for weak solutions, Sobolev embedding theorem and spectral
theory of sub-elliptic operators. We provide the existence and characterization
theorems for extremizing potentials when is subject to
norm constraint
The Analysis of the Difficult Points on Developing E-Commerce of the Western Region in China
From 1999, China started to the project of “Development of Western Region of China” and many preferential policies were issued by the central government. However, after almost 5 years, compared with eastern region, the development of infrastructure is still relatively lower. As to the development of E-commerce, the most typical phenomenon is unbalance which means that the eastern region is much faster than the western because of territorial and economic factors. So it is necessary to get a whole picture and get a clear understanding of problems of current situation of E-commerce in west part of China in order to accelerate it. In this article, the difficult points of E-commerce development in west region are discussed, such as the law issue, infrastructure, information service providers and talents people and some strategies will be given finally based on the current situation of E-commerce in west part of China
Extremal properties of the first eigenvalue and the fundamental gap of a sub-elliptic operator
We consider the problems of extreming the first eigenvalue and the
fundamental gap of a sub-elliptic operator with Dirichlet boundary condition,
when the potential is subjected to a -norm constraint. The existence
results for weak solutions, compact embedding theorem and spectral theory for
sub-elliptic equation are given. Moreover, we provide the specific
characteristics of the corresponding optimal potential function
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