On gradings for one — dimensional seismologic predictions     

Weiping Qin 《地震科学（英文版）》1992,5(1):177-185

This paper gives a complete commentary on some popular gradings which based on the 2×2 contingency table, for one—dimensional seismologic prediction. It contains:

1. In view of the statistical correlation, the Wallen gradingV=√QS is the most equitable one amomg all gradings.
2. Each one of the three gradings: Zhenchao Gu gradingS, Obuhov gradingQ and Shaoxie Xu gradingR, has its own inadequacy although they are so easy for use.
3. A set of gradings can be derived fromV. The harmonic mean ofS andQ, H(S,Q) and the Hedike gradingS _H are the members of this set. The order of some popular gradings are given in Theorem 5. 3.
4. In view of the measure of the overlapping part a gradingW is introduced. Another set of gradings may be derived from it. The index of efficiencyh is the severest one among this set.

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城乡一体化渐进式开发及发展模式研究--以成都市为例     

张果  任平  何景熙 《云南地理环境研究》2006,18(4):58-61

城乡一体化成为当前研究的热点问题之一。成都市从2003年开始，在全市范围内开展城乡一体化试点，准确把握城乡一体化的发展模式，是顺利推进城乡一体化发展的重要一环。根据成都市城乡一体化发展的特点，采用回归方法预测了城市化发展水平，并借鉴国际城市和国内沿海城市的发展经验，提出成都市城乡一体化应采取的总体思路和发展模式，结合成都市城市化水平预测结果，提出其分阶段、分步骤实施的时间阶段。  相似文献   

交互式多目标决策新方法及其在水资源系统规划中的应用   总被引：9，自引：0，他引：9       下载免费PDF全文

王顺久  侯玉  丁晶  张欣莉 《水科学进展》2003,14(4):476-479

在目标满意度和目标总体协调度的基础上构造了一种新的交互式多目标决策方法,运用欧式距离判断来描述目标总体协调度,避免了目标权重人为确定的任意性,且能充分体现决策者的主观愿望,便于实际操作应用.水资源系统规划的多目标决策实例分析表明该方法有效可行.  相似文献   

Analysis of wave groups by wave envelope-phase and the Hilbert Huang transform methods     

《Applied Ocean Research》2016

The wave groups are studied by both conventional wave analysis methods and by the non-stationary Hilbert Huang Transform (HHT) method. Full-scale wave records containing abnormal waves are used. Instantaneous quantities, such as envelope, phase and frequency, are adopted to study the wave grouping. A refined definition of wave group is proposed considering that the wave process is simultaneously amplitude and frequency modulated. The validation of the proposed definition is conducted by analysis of numerical simulation data. Group parameters are proposed based on the time-frequency distribution of energy. An attempt is made to find the relationship between the characteristics of abnormal waves and the group characteristics.  相似文献   

基于多元线性回归分析的页岩气有利区评价新方法——以上扬子地区五峰组—龙马溪组海相页岩为例          下载免费PDF全文

周业鑫  赵安坤  余谦  张娣  张茜  雷子慧 《沉积与特提斯地质》2021,41(3):387-397

本文以四川盆地及其周缘五峰组-龙马溪组页岩气评价为例,总结了页岩气有利区优选的储层参数、保存参数和压力系数等参数,量化了各关键参数平面分布,运用多元线性回归分析方法计算了参数权重,通过多参数加权叠加公式建立了多元线性回归模型：有利区=-0.317+0.75×埋深+0.285×TOC+0.148×R_O+0.093×孔隙度-0.128×渗透率+0.201×脆性矿物-0.199×压力系数,并开展了定量化优选评价页岩气有利区工作。分析结果表明,各参数权重由大到小排序为：埋深、TOC、脆性矿物和压力系数、R_O、孔隙度、渗透率,代表对含气性的影响作用依次减小。经过量化优选的有利区主要集中于四川盆地内,包括威远-自贡一线、宜宾-泸州-涪陵一线和川东区域为主,盆外的昭通、金沙、道真和黔江区域为相对有利区。该预测评价结果与四川盆地页岩气勘探实际基本相符,有利区表现形式较传统综合地质方法更清晰、直观。  相似文献   

岩石边坡基质-植被-大气系统的水分循环          下载免费PDF全文

孙海龙  李绍才  杨志荣  何磊  崔保山 《水科学进展》2006,17(6):818-823

基质-植被系统是岩石边坡植被护坡工程的主要功能构件,其水分循环过程影响工程效应的实现.以高羊茅为建植植物,用TDR水分测定仪对不同表面处理、不同坡度的模拟边坡进行了1年的定位观测试验,研究了岩石边坡基质-植被-大气系统的水分循环过程.结果显示:坡度是影响岩石边坡基质-植被-大气系统水分循环的主要制约因素,坡度增加不仅降低坡面的实际受雨量,同时影响基质的水分输入,系统的蒸散量随坡度增加而降低,但变化幅度较小;试验地气象条件下,生长季的自然降水可满足45°及0°坡面植被所需,75°坡面则出现水分亏缺;由于基质良好的水分物理特性,坡面产流为蓄满产流,受降雨特征及基质初期含水量的影响较小,在同一时空条件下,不同坡面处理的基质含水量表现出微小差异,为喷射混凝土面>灰岩>砂岩.研究从水分循环角度提出了植被护坡技术应用的工程调整措施,为工程应用提供了必要的技术理论支持.  相似文献   

高校贫困生存在的主要道德情感问题及其对策     

饶华  阎钢 《成都信息工程学院学报》2007,22(3):410-415

目前,随着贫困生数量的急剧增加,高校在重视解决贫困生经济困难的同时,往往忽略了他们内心深处潜藏的情绪感受.他们中的大多数产生了不同于一般大学生的道德情感问题.因此,贫困生的道德情感状况、造成此种状况的原因以及培养贫困生的道德情感的路径和方法,便成为对贫困生问题开展深入研究的全新的独特视域.  相似文献   

An evaluation of the exposure in nadir observation of the JEM-EUSO mission     

《Astroparticle Physics》2013

We evaluate the exposure during nadir observations with JEM-EUSO, the Extreme Universe Space Observatory, on-board the Japanese Experiment Module of the International Space Station. Designed as a mission to explore the extreme energy Universe from space, JEM-EUSO will monitor the Earth’s nighttime atmosphere to record the ultraviolet light from tracks generated by extensive air showers initiated by ultra-high energy cosmic rays. In the present work, we discuss the particularities of space-based observation and we compute the annual exposure in nadir observation. The results are based on studies of the expected trigger aperture and observational duty cycle, as well as, on the investigations of the effects of clouds and different types of background light. We show that the annual exposure is about one order of magnitude higher than those of the presently operating ground-based observatories.  相似文献   

Luminescence and radiocarbon chronologies for the Xindian Culture site of Lamafeng in the Guanting Basin on the NE edge of the Tibetan Plateau     

《Quaternary Geochronology》2012

The archaeological Lajia and Lamafeng sites were situated in the Guanting Basin in the northeastern edge of the Tibetan Plateau, and were in the second terrace of the Yellow River. The Lamafeng site is only 1500 m away from Lajia site. The Lajia site belongs to typical Qijia culture (4100–3600 cal a BP). Many human skeletons were found in the Lajia site. These remains presented a state of unnatural deaths. They were all buried in-situ. The Lajia site recorded a prehistoric natural disaster, and the cause of which was probably a combination of earthquake and flooding due to the outburst of a lake that had been dammed by a landslide on the Yellow River. The Lajia site was abandoned by the prehistoric people after the disaster, but follow-up cultural relics were not found. Lamafeng site is a representative of Xindian Culture (3400–2600 cal a BP). The investigation of the Xindian Culture is intensive. However, the chronological data is still very limited, and no luminescence data has been reported so far. In the current study, both optically stimulated luminescence (OSL) (three samples) and accelerator mass spectrometry (AMS) (five charcoal samples) dating are applied to samples from Lamafeng archaeological site. The results showed that: (1) For the sample from the cultural layer, within error margins OSL and ¹⁴C ages are in good agreement. The ¹⁴C ages show that the cultural layer has an age range of ∼2400–2300 cal a BP. (2) The Lamafeng site was inhabited by the people of Xindian Culture, which indicated that the natural disaster occurred in the Qijia culture period did not completely destroy the prehistoric culture in the basin. (3) There was an enhanced extreme flood activity during Qijia and Xindian Culture periods, and the extreme flood period was ended at 2.6 ± 0.2 ka.  相似文献   

区域旅游目的地竞争优势的空间聚类分析——以浙江省为例     

陈思源 《地域研究与开发》2012,31(1):85-88

基于两维图论聚类方法,将主成分分析与两维图论聚类分析有机结合,建立区域旅游目的地竞争优势综合评判模型.首先,建立区域旅游业竞争优势的评价指标体系;接着,利用主成分分析方法对区域旅游竞争优势进行综合评估,并将其应用于浙江省旅游竞争优势评价;最后,以各个旅游目的地的主成分因子为分类对象,采用两维图论聚类法,对各地的旅游竞争优势进行空间聚类分析.研究结果表明,主成分分析与两维图论聚类分析有机结合研究区域旅游目的地的竞争优势是可行的,两维图论聚类能较好地反映区域旅游竞争优势和空间相关性,其结果将有助于决策者制定区域旅游发展战略.  相似文献