排序方式： 共有54条查询结果，搜索用时 15 毫秒
51.
Shutang Zhu 《Ocean Engineering》1999,26(12):535
This paper presents a transfer function method (TFM) which can separate a regular wave field into incident and reflected waves based on the linear wave theory. The TFM uses specific transfer functions and corresponding convolution integrals to separate time series data measured in a combined partial standing wave system into incident and reflected waves. After this separation, estimation of the reflection coefficient becomes very easy. All manipulations have been performed in time domain. Furthermore, this method does not involve the calculation of wave heights and/or phase differences. The present method is demonstrated through numerical sample and physical model experiments carried out in a wave flume. Compared with other methods, the TFM gives much better estimates of the incident wave heights for physical model experiments in this study. 相似文献
52.
This paper systematically investigates spatially autocorrelated patterns and the behaviour of their associated test statistic
Moran's I in three bounded regular tessellations. These regular tessellations consist of triangles, squares, and hexagons, each of
increasing size (n=64; 256; 1024). These tesselations can be downloaded at http://geo-www.sbs.ohio-state.edu/faculty/tiefelsdorf/regspastruc/
in several GIS formats. The selection of squares is particularly motivated by their use in raster based GIS and remote sensing.
In contrast, because of topological correspondences, the hexagons serve as excellent proxy tessellations for empirical maps
in vector based GIS. For all three tessellations, the distributional characteristics and the feasibility of the normal approximation
are examined for global Moran's I, Moran's I
(k) associated with higher order spatial lags, and local Moran's I
i. A set of eigenvectors can be generated for each tessellation and their spatial patterns can be mapped. These eigenvectors
can be used as proxy variables to overcome spatial autocorrelation in regression models. The particularities and similarities
in the spatial patterns of these eigenvectors are discussed. The results indicate that [i] the normal approximation for Moran's
I is not always feasible; [ii] the three tessellations induce different distributional characteristics of Moran's I, and [iii] different spatial patterns of eigenvectors are associated with the three tessellations.
Received: 2 July 1999 / Accepted: 9 November 1999 相似文献
53.
O. Yagci V.S.O. Kirca M.S. Kabdasli A.O. Celik N.E. Unal A. Aydingakko 《Ocean Engineering》2006,33(10):1299-1321
This paper analyses the results of an application of a piled wavescreen. Experimental measurements were undertaken in the laboratory conditions for a given structural configuration under the attack of regular and irregular waves. Dynamic pressure distribution along and around the inclined piles was obtained employing pressure transducers. Using these data, in-line dynamic wave forces acting on piles were also determined. Water particle (orbital) velocities were measured at seaward and landward of the wavescreen using two acoustic Doppler velocimeters (ADV) simultaneously. Furthermore, wave data were collected using resistance type wave gauges at the seaward and landward of the structure. Based on those data, wave attenuation performance of the wavescreen was explored for two different depth values. Findings showed that piled wavescreen can provide effective shore protection as an environmentally friendly coastal structure. 相似文献
54.