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351.
Abstract Wavelet or Fourier analysis is proposed as an alternative nonparametric method to simulate streamflows. An observed series is decomposed into its components at various resolutions and then recombined randomly to generate synthetic series. The mean and standard deviation are perfectly reproduced and coefficient of skewness tends to zero as the number of simulations increases. Normalizing transforms can be used for skewed series. Autocorrelation coefficients and the dependence structure are better preserved when Fourier analysis is used, but the mean and variance remain constant when the simulated and observed series have the same length. Monthly as well as annual flows can be simulated by this technique as illustrated on some examples. Wavelet analysis should be preferred as it generates flow series that exhibit a wider range of required reservoir capacities. 相似文献
352.
B. Thiele R. BostrÖM A. Dumbs K.U. Grossmann D. Krankowsky P. LÄmmerzahl G. Marklund E. Neske G. Schmidtke K. Wilhelm 《Planetary and Space Science》1981,29(4):455-468
Four sounding rocket payloads were launched in early 1977 to measure heating parameters in the auroral oval. Geophysical conditions were different for the four flights: auroral arc substorm main phase diffuse aurora, and auroral arc with negative bay. The conductivity tensor and the heating rates of particle and Joule heating are determined. The heating rates range in the order of a few tens of mWm?2. These magnitudes accord with those determined with the aid of backscatter facilities and other sounding rocket observations. 相似文献
353.
The Kråkenes late-glacial palaeoenvironmental project 总被引:1,自引:0,他引:1
Hilary H. Birks R. W. Battarbee D. J. Beerling H. J. B. Birks S. J. Brooks C. A. Duigan S. Gulliksen H. Haflidason F. Hauge V. J. Jones B. Jonsgard M. Kårevik E. Larsen G. Lemdahl R. Løvlie J. Mangerud S. M. Peglar G. Possnert J. P. Smol J. O. Solem I. Solhøy T. Solhøy E. Sønstegaard H. E. Wright 《Journal of Paleolimnology》1996,15(3):281-286
Kråkenes is the site of a small lake on the west coast of Norway that contains a long sequence of late-glacial sediments. The Younger Dryas is well represented, as a cirque glacier developed in the catchment at this time. This site offers unique opportunities to reconstruct late-glacial environments from independent sources of evidence; physical evidence (glacial geomorphology, sedimentology, palaeomagnetism, radiocarbon dating), and biological evidence from the remains of animals and plants derived from both the terrestrial and aquatic ecosystems. This report describes the background to the site, and the international multidisciplinary project to reconstruct late-glacial and early Holocene environmental and climatic changes at Kråkenes. 相似文献
354.
Vertical and horizontal variations of the frequency of crustal earthquakes (h ≤ 35 km) that have occurred in and around Turkey
are analyzed, using data from the Global Hypocenter Data Base and the IRIS data for the period 1964–1998. Fits of various
magnitude scales to the observations have been used to construct a homogeneous catalogue. Depth distribution of the parameters
derived from the Gutenberg–Richter relationship reveals that there is a depth dependence in the a- and b-values of the frequency
distribution. It is observed that unknown focal depths (0, 10, 33 km) are dominant in the total seismicity reported, and give
rise to substantial changes to the vertical distribution of these parameters. It is also observed that the parameters of either
a or b alone may not be used as a measure of regional seismicity of the study area in which high and low seismic activity
observed over short distances. In contrast, distribution of modal (a/b) values provides detailed images of the local areas
presented by high and low seismic zones. This study presents evidence that low b-values are associated with major strike-slip
faults, particularly exhibiting high apparent stresses.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
355.
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357.
L. KÖlbl 《International Journal of Earth Sciences》1935,26(1-2):151-153
Ohne Zusammenfassung 相似文献
358.
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360.
G. Östlin 《Astrophysics and Space Science》1999,265(1-4):207-210
Representing single stellar populations, globular clusters (GCs) arerelatively easy to model, thus providing powerful tools
for studyingthe evolution of galaxies. This has been demonstrated for the bluecompact galaxy ESO338-IG04. GC systems in galaxies
may be fossils ofstarbursts and mergers. Thus studies of GCs in the local universe mayadd to our understanding of the formation
and evolution of galaxies andthe distant universe.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献