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161.
蒙城地震台地磁绝对观测数据主要通过手工方式计算处理,由于内容多而繁琐,很容易出现人为错误,而且工作效率不高。本文介绍了“蒙城地震台地磁绝对观测数据处理分析软件”,该软件将绝对观测日常数据处理工作有效整合,形成了流程,提高了数据处理效率。并能够对数据进行误差统计、趋势分析等,以了解观测资料的实际状况。 相似文献
162.
E. Earl Whitlatch Peggy L. Asplund 《Journal of the American Water Resources Association》1981,17(2):310-314
ABSTRACT: The cost of water service to rural residents is very high compared to urban areas. This is true even after subsidization by Farmers Home Administration (FmHA) loans and grants. Capital cost data on 44 projects financed by the Ohio office of the FmHA during the period August 1968 to January 1977 are used to derive cost equations for 26 components of rural water distribution systems. These components represent 92 percent of the capital cost of the pipeline distribution systems studied. The data can be used to economically design rural water supply systems from a capital cost viewpoint. More data are needed on operation and maintenance costs as well as central and cluster well costs before totally economic system designs can be undertaken. 相似文献
163.
对地震舆情信息的深入感知和有效管理,能够保障社会和谐发展.提出一个基于大数据技术和深度学习的地震舆情感知平台,基于Hadoop和MongoDB大数据技术实现对海量实时地震舆情数据的处理和存储.基于Word2vec和LSTM的融合模型能够有效实现震后网民的情感识别,为舆情预警提供支持.以台湾5.8级地震舆情数据为例,对该... 相似文献
164.
165.
This paper presents a new clustering algorithm for space–time data based on the concepts of topological data analysis and, in particular, persistent homology. Employing persistent homology—a flexible mathematical tool from algebraic topology used to extract topological information from data—in unsupervised learning is an uncommon and novel approach. A notable aspect of this methodology consists in analyzing data at multiple resolutions, which allows for distinguishing true features from noise based on the extent of their persistence. We evaluate the performance of our algorithm on synthetic data and compare it to other well‐known clustering algorithms such as K‐means, hierarchical clustering, and DBSCAN (density‐based spatial clustering of applications with noise). We illustrate its application in the context of a case study of water quality in the Chesapeake Bay. 相似文献
166.
A new method for calculating return periods of various level values from nonstationary time series data is presented. The key idea of the method is a new definition of the return period, based on the MEan Number of Upcrossings of the level x* (MENU method). In the present article, the case of Gaussian periodically correlated time series is studied in detail. The whole procedure is numerically implemented and applied to synthetic wave data in order to test the stability of the method. Results obtained by using several variants of traditional methods (Gumbel's approach and the POT method) are also presented for comparison purposes. The results of the MENU method showed an extraordinary stability, in contrast to the wide variability of the traditional methods. The predictions obtained by means of the MENU method are lower than the traditional predictions. This is in accordance with the results of other methods that also take into account the dependence structure of the examined time series. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
167.
Richard E. Chandler 《Environmetrics》2005,16(7):699-715
Many topical questions in climate research can be reduced to either of two related problems: understanding how various different components of the climate system affect each other, and quantifying changes in the system. This article aims to justify the addition of generalized linear models to the climatologist's toolkit, by demonstrating that they offer an intuitive and flexible approach to such problems. In particular, we provide some suggestions as to how ‘typical’ climatological data structures may be represented within the GLM framework. Recurring themes include methods for space–time data and the need to cope with large datasets. The ideas are illustrated using a dataset of monthly U.S. temperatures. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
168.
提质增效是目前旅游产业发展面临的重要课题。基于数据包络分析法,选用Python爬取技术,对陕西省107个县域的旅游效率进行测度分析,探讨县域旅游效率的空间格局及其影响的主要因素。研究表明：（1）陕西省旅游效率达到有效的县域数量整体偏低,高旅游效率县域多集中于市辖郊县。（2）县域旅游效率分布不均衡。陕北地区高旅游效率县域主要集中在黄河沿岸,关中地区呈现“西高东低”的现象,陕南地区高旅游效率县域则集中在地市交界处。（3）影响县域旅游总效率、技术效率和规模效率的主导因素不同。旅游收入占GDP比例（反映旅游业水平）、人口密度（反映县域发展水平）及汽车站数量（反映交通服务水平）是影响陕西省县域旅游总效率及技术效率的主导因素,而旅游资源禀赋（反映旅游业水平）、人口密度（反映县域发展水平）则是影响陕西省县域旅游规模效率的主导因素。 相似文献
169.
In order to extract the time‐effect factors of multiple time series, a generalized time‐effect factor model (GTFM) and a statistic for identifying the model are proposed. This model is a general form of the Peña‐Box model. Based on the model, a pollen data set from Taiwan is analyzed. A factor, named temperature, is extracted. Its trend is then used to recover the weather of Taiwan over the past 5000 years. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
170.
As technology progresses, the availability of massive environmental data with global spatial coverage has become quite common. An example of such data is total column ozone (TCO) remotely sensed from a satellite. In their raw form, these data are often spatially (and temporally) dense, but irregular. The problem considered here is one of detecting a large‐scale spatial trend at a given time point (actually, in a given time interval). We propose a sequential aggregation method, producing different levels of coarser (spatial) resolution data and, at the same time, preserving both the local information content and the locations of the raw data. In estimating the large‐scale trend, we consider different types of smooth spatial trend surfaces on the sphere, all linear combinations of smooth basis functions and satisfying the topological constraints imposed by the sphere. These include trend surfaces based on tensor products of splines, spherical harmonic basis functions, smoothing spherical splines and a new trend surface that we call fixed‐rank smoothing (FRS). The FRS trend surfaces can be based on any set of smooth basis functions on the sphere and are estimated via penalized weighted‐least‐squares regression (ridge regression) using a data‐adaptive penalty term. In comparing the various trend surfaces considered, we look at data fidelity, trend‐surface consistency when fitted to data at different resolutions, and small‐ and large‐scale spatial behavior of the resulting detrended fine‐resolution data. An application to the TCO data reveals that the large‐scale spatial trend can be detected and effectively estimated using coarse‐resolution data. The FRS trend surfaces are seen to achieve better data fidelity than other trend surfaces considered, and, in terms of trend‐surface consistency and small‐ and large‐scale residual behavior, FRS is seen to have as good, and sometimes better, performance. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献