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101.
In recent decades, compact urban development and smart cities are recognised as most sustainable urban form in an effort to protect natural environment. Therefore, evaluation of existing compactness and sustainability of an area is an essential task before the real development takes place. In the literature, it is possible to see some studies on city’s compactness assessment and most of them have considered only a few aspects of compact development analysis. This paper aims to analyse urban sustainability of Kajang city (Malaysia) through a comprehensive city compactness assessment using geographical information system and radar remote sensing technology. To measure building density, a RADAR image of the study area was used to extract built-up areas with the aid of pixel-based and object-based classification schemes. Mixed land use development, urban density and intensity were the main indicators of the analysis. Finally, multicriteria decision-making and Bayes theorems were applied for overall compactness assessment. Building density analysis was validated using standard confusion matrix, which showed more than 90% accuracy. Similarly, the root-mean squared error showed 0.35 for object-based classification. The results classified the zones of the Kajang city in the range of least to most compact zones with the compactness value of 0.00273–0.0146, respectively. The results obtained in this study can help local government to improve the compactness of least compact zones to make Kajang city more sustainable. Furthermore, the results revealed that efficient public transportation and proper community facilities are the key factors to achieve sustainable urban development.  相似文献   
102.
Bayes方法及其在地震预报中的应用   总被引:1,自引:0,他引:1  
杨锦英  王碧泉 《内陆地震》1996,10(2):121-129
对Bayes方法进行了分析并将其应用于华北地区强震的预测,结果较好。内符合检验、阈值试验、FH检验、时间窗移动试验等一系列控制试验表明识别结果较稳定。  相似文献   
103.
Physical-chemical explanations of the causes of variations in rock suites are evaluated by comparing predicted to measured compositions. Consistent data turn an explanation into a viable hypothesis. Predicted and measured values seldom are equal, creating problems of defining consistency and quantifying confidence in the hypthesis. Bayes theorem leads to methods for testing alternative hypotheses. Information available prior to data collection provides estimates of prior probabilities for competing hypotheses. After consideration of new data, Bayes theorem updates the probabilities for the hypotheses being correct, returning posterior probabilities. Bayes factors, B, are a means of expressing Bayes theorem if there are two hypotheses, H 0 and H 1. For fixed values of the prior probabilities, B > 1 implies an increased posterior probability for H 0 over its prior probability, whereas B < 1 implies an increased posterior probability for H 1 over its prior probability. Three common problems are: (1) comparing variances in sets of data with known analytical uncertainties, (2) comparing mean values of two datasets with known analytical uncertainties, and (3) determining whether a data point falls on a predicted trend. The probability is better than 0.9934 that lava flows of the 1968 eruption of Kilauea Volcano, Hawaii, are from a single magma batch. The probability is 0.99 that lava flows from two outcrops near Mount Edziza, British Columbia, are from different magma batches, suggesting that the two outcrops can be the same age only by an unlikely coincidence. Bayes factors for hypotheses relating lava flows from Volcano Mountain, Yukon Territory, by crystal fractionation support the hypothesis for one flow but the factor for another flow is so small it practically guarantees the fractionation hypothesis is wrong. Probabilities for petrologic hypotheses cannot become large with a single line of evidence; several data points or datasets are required for high probabilities.  相似文献   
104.
The Bayesian Maximum Entropy (BME) method of spatial analysis and mapping provides definite rules for incorporating prior information, hard and soft data into the mapping process. It has certain unique features that make it a loyal guardian of plausible reasoning under conditions of uncertainty. BME is a general approach that does not make any assumptions regarding the linearity of the estimator, the normality of the underlying probability laws, or the homogeneity of the spatial distribution. By capitalizing on various sources of information and data, BME introduces an epistemological framework that produces predictive maps that are more accurate and in many cases computationally more efficient than those derived by traditional techniques. In fact, kriging techniques can be derived as special cases of the BME approach, under restrictive assumptions regarding the prior information and the data available. BME is a more rigorous approach than indicator kriging for incorporating soft data. The BME formulation, in fact, applies in a spatial or a spatiotemporal domain and its extension to the case of block and vector random fields is straightforward. New theoretical results are presented and numerical examples are discussed, which use the BME approach to account for important sources of knowledge in a systematic manner. BME can be useful in practical situations in which prior information can be used to compensate for the limited amount of measurements available (e.g., preliminary or feasibility study levels) or soft data are available that can be combined with hard data to improve mapping significantly. BME may be then viewed as an effort towards the development of a more general framework of spatial/temporal analysis and mapping, which includes traditional geostatistics as its limiting case, and it also provides the means to derive novel results that could not be obtained by traditional geostatistics.  相似文献   
105.
土性参数相关距离的计算研究和统计分析   总被引:6,自引:0,他引:6  
李小勇  谢康和 《岩土力学》2000,21(4):350-353
通过大量计算,对求相关距离的各种方法进行了对比研究,对太原和杭州地区典型土层的相关距离进行李统计分析,还结合某一工程实例讨论了相关距离估计的贝叶斯方法。  相似文献   
106.
Inference about the existence and characteristics of changes in mean level of hydrometeorological sequences that may be generated by climatic variability is an important step before developing management rules in water resources systems. This paper presents a Bayesian approach, based on a single shifting model, which can be used to study a change in the mean level of a set of independent normal random variables. Two different problems are considered: the first is the detection of a change, while the second is the estimation of the change-point and its amplitude under the assumption that a change has occurred. This method is applied to precipitation and runoff data series over eastern Canada and U.S. during the twentieth century. The main results show an increase in the late sixties in the Eastern North American precipitation. This supports conclusions drawn from a number of studies which identified the late sixties to early seventies as a period of possible change.  相似文献   
107.
以系统的观点,基于可靠性理论对石河子市电力工程系统进行了震害预测。通过整体分析与局部评估讨论了电力系统的可靠性;提出未来地震发生后系统的潜在灾害率。  相似文献   
108.
用贝叶斯分类方法和本体实现空间信息语义互操作   总被引:1,自引:0,他引:1  
构建了异构空间信息系统语义互操作的框架,通过基于本体的语义异构空间信息的概念级匹配机制,并利用贝叶斯分类方法完成空间信息实例级的重分类,实现了语义互操作。  相似文献   
109.
晚期强余震往往会使曾经历过主震破坏后重建的地区再次遭受预想不到的损失。本文在较系统地整理资料的基础上,初步获得中国大陆主震后10年内强余震活动的部分统计特征,并初步尝试利用主震后1个月的资料,运用推广的贝叶斯公式对主震后2月—10年期间是否会发生强余震进行判别。同时,分析了强余震与主震空间位置的关系。结果表明:①主震后10年内有强余震的占总数1/3,主余震型地震超过总数1/4,强余震频次随时间衰减很快。②以主震后1月内的强余震资料用推广的贝叶斯公式,可以判别出2月—10年期间是否会发生强余震。③上述方法的Wallcn评分结果比较好。  相似文献   
110.
渤海海域中生界火山岩岩石类型复杂多样,且同一岩性受岩石成分、结构差异的影响,因此岩石物理响应特征存在较大差异,为岩性识别增加了难度。本文通过对研究区大量取心资料、壁心资料以及薄片资料的岩电分析,优选出对岩性响应敏感的自然伽马(GR)、补偿中子(CNL)、密度(DEN)、声波时差(AC)以及原状地层电阻率(Rd)等5条曲线。基于主成分分析法,构建了F_1—F_5共5个综合变量,其中F_1和F_2方差贡献率占总贡献率的81.4%,可作为两个主成分有效地反映5个变量的信息。针对主成分信息,利用Bayes判别法,构建了不同岩性的定量解释模型,对研究区9种火山岩进行了岩性识别。对取心井段的回判结果显示,基于主成分分析与Bayes判别的联合识别方法较常规交会图法在岩石成分及结构的识别精度方面均有较大程度的提高。该方法的提出对研究区成像测井、元素测井资料缺少井段的火山岩岩性识别具有重要借鉴作用。  相似文献   
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