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Omkar M. Shrestha Achyuta Koirala Jörg Hanisch Klaus Busch Martin Kerntke Stefan Jäger 《GeoJournal》1999,49(2):165-172
An engineering and environmental geological map of the Kathmandu Valley in Nepal has been elaborated within a project of German-Nepalese
cooperation. In the Kathmandu Valley, the major geo-environmental problems arise from haphazard exploitation of geologic resources,
local landslide zones, severe problems of garbage disposal, river flooding and a dramatic river pollution. The map was prepared
by the use of GIS techniques. It contains all basic geological and environmental data, as geotechnical risk zones (landslide-prone
areas or those of poor foundation conditions), areas for preferable extraction of construction material and those not to be
allowed to be exploited, areas of immediate need of reforestation in order to prevent landslide or badland development, groundwater
protection zones, and suitable garbage disposal sites.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
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Crop classification using biologically-inspired techniques with high resolution satellite image 总被引:5,自引:0,他引:5
S. N. Omkar J. Senthilnath Dheevatsa Mudigere M. Manoj Kumar 《Journal of the Indian Society of Remote Sensing》2008,36(2):175-182
Remote sensing provides a lucid and effective means for crop coverage identification. Crop coverage identification is a very
important technique, as it provides vital information on the type and extent of crop cultivated in a particular area. This
information has immense potential in the planning for further cultivation activities and for optimal usage of the available
fertile land. As the frontiers of space technology advance, the knowledge derived from the satellite data has also grown in
sophistication. Further, image classification forms the core of the solution to the crop coverage identification problem.
No single classifier can prove to satisfactorily classify all the basic crop cover mapping problems of a cultivated region.
We present in this paper the experimental results of multiple classification techniques for the problem of crop cover mapping
of a cultivated region. A detailed comparison of the algorithms inspired by social behaviour of insects and conventional statistical
method for crop classification is presented in this paper. These include the Maximum Likelihood Classifier (MLC), Particle
Swarm Optimisation (PSO) and Ant Colony Optimisation (ACO) techniques. The high resolution satellite image has been used for
the experiments. 相似文献
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Omkar 《洁净——土壤、空气、水》1986,14(2):185-189
In vitro effects of aldrin on acid and alkaline phosphatase activities in various tissues, viz. hepatopancreas, stomach, muscle, gill and brain, of a freshwater prawn Macrobrachium lamarrei have been studied. Aldrin exposure inhibited the activities of both the phosphatases in all the tissues and this inhibition in enzyme activity showed a dose-dependent response. The results were discussed in relation to in vivo findings and it is concluded that aldrin causes some enzymological changes and thereby creates widespread disturbance in the metabolism. 相似文献
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Automatic road extraction using high resolution satellite image based on texture progressive analysis and normalized cut method 总被引:1,自引:0,他引:1
J. Senthilnath M. Rajeshwari S. N. Omkar 《Journal of the Indian Society of Remote Sensing》2009,37(3):351-361
In this paper the approach for automatic road extraction for an urban region using structural, spectral and geometric characteristics
of roads has been presented. Roads have been extracted based on two levels: Pre-processing and road extraction methods. Initially,
the image is pre-processed to improve the tolerance by reducing the clutter (that mostly represents the buildings, parking
lots, vegetation regions and other open spaces). The road segments are then extracted using Texture Progressive Analysis (TPA)
and Normalized cut algorithm. The TPA technique uses binary segmentation based on three levels of texture statistical evaluation
to extract road segments where as, Normalized cut method for road extraction is a graph based method that generates optimal
partition of road segments. The performance evaluation (quality measures) for road extraction using TPA and normalized cut
method is compared. Thus the experimental result show that normalized cut method is efficient in extracting road segments
in urban region from high resolution satellite image. 相似文献
7.
Omkar Verma Guntupalli V.R. PrasadAnjali Goswami Varun Parmar 《Cretaceous Research》2012,33(1):183-188
Although a very high invertebrate faunal diversity is known from the outcrops of the Ariyalur group in the Cauvery Basin, southern India, little is known about its vertebrate fauna. Recent fieldwork in the badland exposures of the Karai Formation (Upper Cenomanian-Lower Turonian) near Garudamangalam in the basin has yielded two teeth belonging to the Late Cretaceous shark Ptychodus decurrens (Ptychodontidae). The fossil record of Ptychodus decurrens from the southern continents is very poor, being known from a single Late/Middle Albian occurrence in Australia. This finding documents the first record of fossil P. decurrens in India and second from a Gondwanan landmass, and provides the first evidence of a cosmopolitan, Pangaean, distribution of the species during the Albian-Turonian and additional insights into the palaeoecology of the Cauvery Basin during the deposition of the Karai Formation. 相似文献
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The oscillatory nature of wave-particle interaction is proposed to be the source of non-local fluctuations in the electron energy. The energized electron flux when precipitated in the lower ionosphere gives rise to various geophysical phenomena. The time scale of energy oscillation is estimated and its validity is discussed with reference to observed time scales of various geophysical phenomena. 相似文献
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In batch experiments with exposure for 24 to 96 h Macrobrachium naso and M. dayanum were exposed to solutions of the sodium salt of 2,4-dichlorophenoxy acetic acid. The LC50,96h are 2.397 g/l for Macrobrachium naso and 2.275 g/l for M. dayanum. No mortality was observed in solutions of 2.1 and 1.85 g/l. The differences in toxicity are not dependent on the size of the organisms, but they are species-specific. 相似文献
10.
Macrobrachium lamarrei is exposed to 0.008, 0.017 and 0.021 mg/1 aldrin (0.4, 0.8 and 1.0 of the LC50,96h) for 24… 96 h and after exposure the activities of the acid, alkaline and glucose-6-phosphatases are determined. With concentration and time of exposure the acid phosphatase shows an increasing activity up to 170 % compared with the control, which is interpreted as a part of prenecrotic changes in the cells. With concentration and time of exposure the alkaline phosphatase shows a decreasing activity down to 20 % of the control, which is indicative of considerable disturbances of the total metabolism. The glucose-6-phosphatase shows an increasing activity with the aldrin concentration up to 150 % during 72 h; then the activity drops to 60… 80 %. The initial rise in the glucose concentration of blood caused by that is the clear consequence of a stress reaction and the change of metabolism resulting from it. 相似文献