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Heiko Drachenfels 《Informatik-Spektrum》1997,20(5):286-293
Eingegangen am 13.11.1996, in überarbeiteter Form am 12.5.1997 相似文献
3.
Charles George Clare Rowland France Gerard Heiko Balzter 《Remote sensing of environment》2006,104(3):346-359
The boreal forest contains almost half the total carbon pool of world forest ecosystems, and so has a very significant role in global biogeochemical cycles. The flux of greenhouse gases in and out of these forests is influenced strongly by disturbances such as diseases, logging and predominantly fire. It is important to quantify these disturbances to enable the modelling of major greenhouse gases. However, because of the remoteness and vastness of the boreal forest, little data is available on the type, extent, frequency and severity of these disturbances in Siberia. For burnt areas, two of the more responsive wavelengths are the short wave infra-red (SWIR) and the near infra-red (NIR). These produce a vegetation index, the normalised difference SWIR (NDSWIR) capable of detecting retrospective disturbances. Here we combine the NDSWIR from MODIS imagery acquired in the summer of 2003 with thermal anomaly data from 1992 to 2003 to detect and date areas which burnt at some point between 1992 and 2003. The semi-automated method is called SWIR and Thermal ANomalies for Detecting Disturbances (STANDD) and is complemented by an Normalised Difference Vegetation Index (NDVI) differencing method using MODIS 2002 and 2003 imagery to ensure reliable detection of area burnt in the year of image acquisition (i.e. 2003). The area of this study covers approximately 3 million km2 stretching from Lake Baikal in the south to the Laptev Sea in the north, above the Arctic Circle. Landsat ETM+ images were used to validate the shape and areal extent of the burnt areas resulting in an 81% overall accuracy with a kappa coefficient of agreement of 0.63. 相似文献
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Leonardo Candela Fuat Akal Henri Avancini Donatella Castelli Luigi Fusco Veronica Guidetti Christoph Langguth Andrea Manzi Pasquale Pagano Heiko Schuldt Manuele Simi Michael Springmann Laura Voicu 《International Journal on Digital Libraries》2007,7(1-2):59-80
This paper introduces DILIGENT, a digital library infrastructure built by integrating digital library and Grid technologies and resources. This infrastructure
allows different communities to dynamically build specialised digital libraries capable to support the entire e-Science knowledge
production and consumption life-cycle by using shared computing, storage, content, and application resources. The paper presents
some of the main software services that implement the DILIGENT system. Moreover, it exemplifies the provided features by presenting how the DILIGENT infrastructure is being exploited in supporting the activity of user communities working in the Earth Science Environmental
sector.
This work is partially funded by the European Commission in the context of the DILIGENT project, under the 2nd call of FP6 IST priority. 相似文献
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E Prescott M Osler PK Andersen A Bjerg HO Hein K Borch-Johnsen P Lange P Schnohr J Vestbo 《Canadian Metallurgical Quarterly》1997,26(6):1214-1218
BACKGROUND: Two recent much cited publications have raised the concern that risk associated with cigarette smoking has so far been underestimated. In this study we wish to determine whether excess all-cause mortality associated with smoking has increased during the last 20-30 years in a study population representative of the general Danish population and whether any such changes relate to changes in smoking behaviour. METHODS: Pooled data from three prospective population studies conducted in Copenhagen with detailed information on smoking habits. A total of 31,194 subjects, 17,669 males and 13,525 females, initially examined between 1964 and 1992 with examinations repeated at intervals from 1-10 years, were followed until 1995 for all-cause mortality. Relative mortality risk in smokers versus never-smokers was calculated within periods of five calendar years and compared throughout the study period. RESULTS: Male smokers' exposure did not change during the study period whereas female smokers' exposure to tobacco increased in terms of age at smoking onset, quantity smoked and depth of inhalation. During follow-up 5744 males and 2900 females died. In males, death rate ratios (comparing continuous smokers with never-smokers) did not change in the study period. In females, ratios increased from 1964-1978 to 1979-1994 by a factor of 1.3 (95% confidence interval 1.0-1.8). CONCLUSIONS: In agreement with the observed changes in smoking habits, excess mortality in male smokers did not increase whereas excess mortality in female smokers increased slightly. 相似文献
6.
Common region of ALL-1 gene disrupted in epipodophyllotoxin-related secondary acute myeloid leukemia
CA Felix NJ Winick M Negrini WP Bowman CM Croce BJ Lange 《Canadian Metallurgical Quarterly》1993,53(13):2954-2956
Translocations at chromosomal band 11q23 characterize most de novo acute lymphoblastic leukemias (ALL) of infants, acute myeloid leukemias (AML) of infants and young children, and secondary AMLs following epipodophyllotoxin exposure. The chromosomal breakpoints at 11q23 have been cloned from isolated cases of de novo ALL and AML. Using an 859-base pair BamHI fragment of human ALL-1 complementary DNA that recognizes the genomic breakpoint region for de novo ALL and AML, we investigated two cases of secondary AML that followed etoposide-treated primary B-lineage ALL. In the first case, the translocation occurred between chromosomes 9 and 11 and the breakpoint at 11q23 localized to the same 9-kilobase region of the ALL-1 gene that is disrupted in most of the de novo leukemias. In the second case the translocation was between chromosomes 11 and 19. The breakpoint occurred outside of the ALL-1 breakpoint cluster region. 相似文献
7.
G. Lange 《Materialwissenschaft und Werkstofftechnik》2003,34(1):80-85
Failures by notch induced fatigue fractures Notches produce local stress concentrations and promote the formation of fatigue cracks. Characteristic types of notches as a result of design, manufacturing and operation are presented and remedial measures are discussed. Examples demonstrate the effect of different kinds of notches on various components. 相似文献
8.
P. K. Chaviaropoulos I. G. Nikolaou K. A. Aggelis N. N. Soerensen J. Johansen M. O. L. Hansen Mac Gaunaa T. Hambraus Heiko Frhr. von Geyr Ch. Hirsch Kang Shun S. G. Voutsinas G. Tzabiras Y. Perivolaris S. Z. Dyrmose 《风能》2003,6(4):365-385
Aerodynamic modelling of HAWT rotors by means of “engineering methods” has reached a saddle point, where no further development can be expected without a breakthrough in understanding the physics of unsteady, rotating three‐dimensional flows. However, such a breakthrough becomes ever more necessary, as the size of the wind turbines increases. With the experimental work in that direction being mostly limited to observing the phenomena and interpreting the associated mechanisms, and its increased cost, alternatives are being sought. The use of CFD techniques and state‐of‐the‐art Navier–Stokes solvers is considered a very serious contender, a belief shared by the members of the present consortium, which has worked on the VISCEL JOR3‐CT98‐0208 Joule III project. This project's goal was to determine the aerodynamic characteristics as well as the aeroelastic behaviour of wind turbine blades across their broad range of operational conditions, from attached to highly separated flow regimes. The work programme included specific tasks for the validation and assessment of existing 3D solvers, for the parametric study of 3D flow around realistic blades and for the investigation of aeroelastic stability, at the blade section level. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
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