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581.
构建上海市地价管理体系的设想 总被引:1,自引:0,他引:1
上海是我国经济与金融中心,随着城市建设的快速发展和房地产业的蓬勃兴旺,上海成为我国土地交易最为活跃的地区之一。本文通过对我市基准地价、城市地价动态监测两项工作的探讨,展开对构建上海市地价管理体系的设想。 相似文献
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583.
The smoothness of HASM 总被引:1,自引:0,他引:1
Chuanfa Chen Tianxiang Yue Honglei Dai Maoyi Tian 《International journal of geographical information science》2013,27(8):1651-1667
To smooth noises inherent in uniformly sampled dataset, the smoothness of high accuracy surface modeling (HASM) was explored, and a smoothing method of HASM (HASM-SM) was developed based on a penalized least squares method. The optimal smoothing parameter of HASM-SM was automatically obtained by means of the generalized cross-validation (GCV) method. For an efficient smoothing computation, discrete cosine transform was employed to solve the system of HASM-SM and to estimate the minimum GCV score, simultaneously. Two examples including a numerical test and a real-world example were employed to compare the smoothing ability of HASM-SM with that of GCV thin plate smoothing spline (TPS) and kriging. The numerical test indicated that the minimum GCV HASM-SM is averagely more accurate than TPS and kriging for noisy surface smoothing. The real-world example of smoothing a lidar-derived Digital Elevation Model (DEM) showed that HASM-SM has an obvious smoothing effect, which is on a par with TPS. In conclusion, HASM-SM provides an efficient tool for filtering noises in grid-based surfaces like remote sensing–derived images and DEMs. 相似文献
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Sparsity constrained deconvolution can improve the resolution of band-limited seismic data compared to conventional deconvolution. However, such deconvolution methods result in nonunique solutions and suppress weak reflections. The Cauchy function, modified Cauchy function, and Huber function are commonly used constraint criteria in sparse deconvolution. We used numerical experiments to analyze the ability of sparsity constrained deconvolution to restore reflectivity sequences and protect weak reflections under different constraint criteria. The experimental results demonstrate that the performance of sparsity constrained deconvolution depends on the agreement between the constraint criteria and the probability distribution of the reflectivity sequences; furthermore, the modified Cauchyconstrained criterion protects the weak reflections better than the other criteria. Based on the model experiments, the probability distribution of the reflectivity sequences of carbonate and clastic formations is statistically analyzed by using well-logging data and then the modified Cauchy-constrained deconvolution is applied to real seismic data much improving the resolution. 相似文献
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利用SOHO/SEM在1996-2008年的太阳EUV观测数据,比较和评估F10.7和Mg II作为EUV代理参数的代表性,不能支持Viereck等关于Mg II是比F10.7更好的代理参数的结论.通过比较对两种参数的多种回归计算结果,确立双因子极大似然估计方法构建EUV计算模式,通过模型计算结果与SEM观测数据比较,表明该模型能够很好地重建EUV数据系列.利用该模式,构建了1978年11月以来的太阳极紫外辐射数据序列. 相似文献
589.
Fine round gravel soil is widely employed in the subgrade of high speed railways in cold regions to prevent frost heaving
and thawing. The lower the fines content in fine round gravel soil, the smaller the quantities of frost heaving and thawing,
but compaction difficulty increases. This study is to obtain the optimum fines content and limited frost heaving and
thawing. The fine round gravel soil filling (FRGSF) used in the Harbin-Qiqihaer Passenger Dedicated Line is taken as the
study object. Influence of fines content on optimum water content, maximum dry density and frost heaving properties of
FRGSF were studied by means of compaction and frost heaving tests. Results show that the maximum dry density of the
FRGSF increases first and then decreases with an increase of fines content, namely there is an optimum fines content for
easy compaction. The method of surface-vibratory instrument is fit for coarse-grained soils, and wet state of
coarse-grained soil is in favor of compaction. Considering the relationship of fines content with maximum dry density and
the frost heaving ratio of FRGSF, the fines content should be limited to within the range of 9%-10%, so that the frost
heaving ratio is less than 1%, and the FRGSF is easily compacted. Water supply is proved to be an important factor influencing
the amount of frost heaving of FRGSF. We also conclude that in the field, it is imperative to control waterproofing
and drainage measures. 相似文献
590.
Lake area information in the Badain Jaran Desert in 1973, 1990, 2000, and 2010 was obtained by visual interpretation and water
index analysis of remote sensing images, based on the spatial and temporal characteristics of lake area changes during 37 years.
Results indicated that the number of lakes declined from 94 to 82 and the total surface area was reduced by 3.69 km2 during
1973–2010. The desert lake area reduced by different degrees in different periods, but this occurred most rapidly during
1973–1990. According to the statistics of lake area changes, lake area decreases mainly occurred in the lakes with areas less than
0.2 km2, while the areas of lakes greater than 0.9 km2 only fluctuated. The changes of lake areas were probably due to changes in
the quantity of underground water supplies rather than the effects of local climate change or human factors. 相似文献