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51.
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Thomas Oommen Debasmita Misra Navin K. C. Twarakavi Anupma Prakash Bhaskar Sahoo Sukumar Bandopadhyay 《Mathematical Geosciences》2008,40(4):409-424
Accurate thematic classification is one of the most commonly desired outputs from remote sensing images. Recent research efforts
to improve the reliability and accuracy of image classification have led to the introduction of the Support Vector Classification
(SVC) scheme. SVC is a new generation of supervised learning method based on the principle of statistical learning theory,
which is designed to decrease uncertainty in the model structure and the fitness of data. We have presented a comparative
analysis of SVC with the Maximum Likelihood Classification (MLC) method, which is the most popular conventional supervised
classification technique. SVC is an optimization technique in which the classification accuracy heavily relies on identifying
the optimal parameters. Using a case study, we verify a method to obtain these optimal parameters such that SVC can be applied
efficiently. We use multispectral and hyperspectral images to develop thematic classes of known lithologic units in order
to compare the classification accuracy of both the methods. We have varied the training to testing data proportions to assess
the relative robustness and the optimal training sample requirement of both the methods to achieve comparable levels of accuracy.
The results of our study illustrated that SVC improved the classification accuracy, was robust and did not suffer from dimensionality
issues such as the Hughes Effect. 相似文献
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The horizontal pullout capacity of a group of two rigid strip plate anchors embedded along the same vertical plane in clays, under undrained condition, has been determined. An increase of cohesion with depth has also been incorporated. The analysis has been performed by using an upper bound finite element limit analysis in combination with linear optimization. For different clear spacing (S) between the anchors, the efficiency factor (ηcγ) has been determined to evaluate the group failure load for different values of (1) embedment ratio (H/B), (2) the normalized rate (m) which accounts for a linear increase of cohesion with depth, and (3) normalized unit weight (γH/co). The magnitude of the group failure load (1) becomes maximum corresponding to a certain spacing (Scr) between the anchors, and (2) increases with an increase in the γH/co up to a certain value before attaining a certain maximum magnitude. The value of Scr/B has been found to vary generally between 0.7 and 1.2. The maximum magnitude of ηcγ, associated with the critical spacing, (1) increases generally with increases in H/B, and (2) decreases with an increase in m. For a greater spacing between the anchors, the analysis reveals the development of a local shear zone around the lower anchor plate. The numerical results developed are expected to be useful for purpose of design. 相似文献
56.
Neeraj Kumar Sharma S. K. Swain Umesh C. Sahoo 《Geotechnical and Geological Engineering》2012,30(5):1197-1205
Pavement structures on poor soil sub grades show early distresses causing the premature failure of the pavement. Clayey soils usually have the potential to demonstrate undesirable engineering behavior, such as low bearing capacity, high shrinkage and swell characteristics and high moisture susceptibility. Stabilization of these soils is a usual practice for improving the strength. This study reports the improvement in the strength of a locally available cohesive soil by addition of both fly ash and lime. Analysis using X-ray diffraction, scanning electron microscopy, coupled with energy dispersive spectroscopy, thermal gravimetric analysis, zeta potential and pH value test was carried out in order to elucidate the stabilization mechanism. The micro level analysis confirmed the breaking of montmorrillonite structure present in the untreated clay after stabilization. In the analysis, it was also confirmed that in the stabilization process, pozzolanic reaction dominated over the cation exchange capacity. 相似文献
57.
In this paper we have taken an attempt to construct a five dimensional perfect fluid cosmological model within the framework
of Lyra manifold. It is found that neither perfect fluid nor dust distributions survive. Finally the exact solutions of the
vacuum field equations are obtained. 相似文献
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In this paper, we have investigated Bianchi type VI h cosmological model filled with perfect fluid in the framework of f(R,T) gravity, where R is the Ricci scalar and T is the trace of the energy-momentum tensor proposed by Harko et al. (Phys. Rev. D 84:024020, 2011). We have obtained the cosmological models by solving the field equations. Some physical behaviors of the model are also studied. 相似文献
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The response of Lake Tahoe to climate change 总被引：2，自引：0，他引：2
G. B. Sahoo S. G. Schladow J. E. Reuter R. Coats M. Dettinger J. Riverson B. Wolfe M. Costa-Cabral 《Climatic change》2013,116(1):71-95
Meteorology is the driving force for lake internal heating, cooling, mixing, and circulation. Thus continued global warming will affect the lake thermal properties, water level, internal nutrient loading, nutrient cycling, food-web characteristics, fish-habitat, aquatic ecosystem, and other important features of lake limnology. Using a 1-D numerical model—the Lake Clarity Model (LCM) —together with the down-scaled climatic data of the two emissions scenarios (B1 and A2) of the Geophysical Fluid Dynamics Laboratory (GFDL) Global Circulation Model, we found that Lake Tahoe will likely cease to mix to the bottom after about 2060 for A2 scenario, with an annual mixing depth of less than 200 m as the most common value. Deep mixing, which currently occurs on average every 3–4 years, will (under the GFDL B1 scenario) occur only four times during 2061 to 2098. When the lake fails to completely mix, the bottom waters are not replenished with dissolved oxygen and eventually dissolved oxygen at these depths will be depleted to zero. When this occurs, soluble reactive phosphorus (SRP) and ammonium-nitrogen (both biostimulatory) are released from the deep sediments and contribute approximately 51 % and 14 % of the total SRP and dissolved inorganic nitrogen load, respectively. The lake model suggests that climate change will drive the lake surface level down below the natural rim after 2085 for the GFDL A2 but not the GFDL B1 scenario. The results indicate that continued climate changes could pose serious threats to the characteristics of the Lake that are most highly valued. Future water quality planning must take these results into account. 相似文献