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141.
针对传统空间关联规则挖掘对数据硬化分导致的"尖锐边界"问题,提出了一种顾及模糊属性的空间关联规则挖掘方法。该方法引入模糊集理论,将模糊空间属性通过隶属函数转化为隶属度表示的模糊数值,从而将其划分为模糊集合。然后使用改进的模糊关联规则挖掘算法扫描数据库,根据相应的支持度得到频繁项集,最终提取出关联规则。实验结果表明,该方法能够对带有模糊属性的空间数据进行关联规则挖掘,且在一定程度上提高了挖掘结果的兴趣度。 相似文献
142.
引入数据关联规则挖掘技术,分析地面观测中不同气象要素之间的相互关系,为不同气象要素观测数据的内部一致性检查提供参考。通过对2013年全年北京南郊试验站地面气象自动观测数据的分析,统计出了强关联规则气象观测要素相应的值域分布区间。分析了相对湿度和风速变化值之间的相关性,得到相对应的变化阈值;通过分析能见度与相对湿度的相关性,发现能见度变化受降水影响较大,因此,统计不同等级降雨强度所对应的能见度区间值,通过分析具体降水过程,揭示能见度与降雨强度随时间的变化关系,结果表明,利用上述相关性对气象要素观测数据进行判定,可以为多种气象观测数据的质量控制提供参考。 相似文献
143.
Very high spatial and temporal resolution remote sensing data facilitate mapping highly complex and diverse urban environments. This study analyzed and demonstrated the usefulness of combined high-resolution aerial digital images and elevation data, and its processing using object-based image analysis for mapping urban land covers and quantifying buildings. It is observed that mapping heterogeneous features across large urban areas is time consuming and challenging. This study presents and demonstrates an approach for formulating an optimal land cover classification rule set over small representative training urban area image, and its subsequent transfer to the multisensor, multitemporal images. The classification results over the training area showed an overall accuracy of 96%, and the application of rule set to different sensor images of other test areas resulted in reduced accuracies of 91% for the same sensor, 90% and 86% for the different sensors temporal data. The comparison of reference and classified buildings showed ±4% detection errors. Classification through a transferred rule set reduced the classification accuracy by about 5%–10%. However, the trade-off for this accuracy drop was about a 75% reduction in processing time for performing classification in the training area. The factors influencing the classification accuracies were mainly the shadow and temporal changes in the class characteristics. 相似文献
144.
Majid Mathlouthi Fethi Lebdi 《Stochastic Environmental Research and Risk Assessment (SERRA)》2008,22(4):513-528
The paper focuses on the development of reservoir operating rules for dry and rainfall events, and their implementation in
the case of the Ghézala dam located in northern Tunisia (characterized by Mediterranean climate). Rainfall events are defined
in terms of depth and duration that are correlated to each other. A depth analysis per event is performed, conditioned on
the event duration. The gamma distribution provides a good fit to depth per event, especially for events lasting at least
6 days. The event duration fits a geometric distribution, whereas the dry events during the rainy season fit a negative binomial
distribution. The climatic cycle length is fitted to a gamma distribution. On this basis, many 50-year synthetic event series
were generated. Every synthetic streamflow sequence obtained from synthetic rainfall sequences as well as the one derived
from the historic rainfall events time series were optimized and optimal decisions were formulated. These decisions were assessed
by means of multiple regression analysis to estimate the relation between the optimal decision to every stage (dry or rainfall
event) and other system variables. Optimal rules, which have a linear form, were derived by predetermined useful storage interval
and depend on storage, inflows and downstream demand at dry or rainfall event t. The range of t is 1–13 days (rainfall event) and 1–57 days (dry event). The rules were satisfactory for every predetermined useful storage
interval. The simulated dam performance generated by the operation rules was compared with the deterministic optimum operation
and the historical operation. Also included is the comparison of the implicit stochastic optimization-based operation policy
per event during the water years 1985–2002.
相似文献
Fethi LebdiEmail: |
145.
地质灾害防治立法是地质灾害防治走向法治化、制度化的重要标志。作者在分析我国地质灾害防治立法建设存在问题基础上,提出了全国地质灾害防治立法建议,并针对陕西省地质灾害防治法规建设构想了具体框架。 相似文献
146.
In order to explore the regularity between Wanrendong gold deposit and geophysical electrical characteristics and expand thoughts for Wanrendong gold deposit prospecting, the authors comprehensively investigated the electrical structural characteristics of Wanrendong gold mine area, through the introduction of geological and physical characteristics of Wanrendong gold deposit, as well as the CSAMT (controlled source audio magnetotelluric method) basic theory and the transitivity measurement work. The spatial distribution characteristics of gold deposit-related geologic body, structure, and alteration was identified, and the prospecting geophysical rules of gold deposit were summarized in this paper. The gold deposit was mostly distributed in the geophysical low resistance anomaly areas, or transition areas between high resistance and low resistance. This method proved to be effective and dependable after later borehole certification. These achievements could provide geophysical exploration method of gold-prospecting for Wamrendong gold deposit area or similar areas. 相似文献
147.
分时租赁和网约车同属共享汽车,但规模对比悬殊。找到差异化的出行场景有利于分时租赁在网约车主导的共享汽车市场中谋求立足之地。本文以北京地区某分时租赁公司2017年5月1日—30日的出行订单和2018年4月23日—29日的网约车出行订单为研究对象,结合城市兴趣点数据,利用地理信息层次聚类、关联规则等方法挖掘两共享汽车的典型出行场景,并进行比较分析。研究表明:① 网约车主要服务于“通勤出行”和“市内商务区之间的出行”,2种出行场景分别占网约车订单总量的40.3%和28.7%;② 分时租赁主要服务非通勤出行,其特色出行场景是“往返城市旅游景区的出行”、“城市旅游景区之间的出行”和“外城住宅商务混合区的午夜出行”,分别占分时租赁订单总量的24.4%、6.9%和5.5%。③ 在分时租赁的特色出行场景中,分时租赁与网约车或传统租车等共享出行方式相比费用更低,仅占其费用的25%~35%,具有较大的竞争优势。本研究有关出行场景挖掘的方法和结论可以为北京市分时租赁的推广以及其他共享出行研究提供借鉴和参考。 相似文献
148.
云南省马厂箐铜钼金多金属矿床地质特征及成矿规律 总被引:4,自引:0,他引:4
马厂箐铜钼金多金属矿床位于云南省祥云、弥渡、大理三市县接壤部位,是金沙江-哀牢山构造带上典型的与喜马拉雅期富碱斑岩有关的矿床之一。富碱斑岩体内发育斑岩型铜钼矿化,岩体与围岩接触带产出接触交代型铜钼矿化,围岩地层中则产出浅成低温热液型金、铅、锌矿化。下奥陶统向阳组一套碎屑岩和下泥盆统康郎组灰岩与铜钼金成矿关系密切。铜钼矿的成矿物质主要来源于地幔或岩浆流体,金矿成矿物质由岩浆和围岩地层共同提供。区内喜马拉雅期的富碱斑岩与铜钼金成矿成矿关系密切,不仅提供了成矿金属物质,而且还提供了成矿流体和成矿动力。伴随马厂箐岩体侵入而形成的一套岩浆侵入接触构造体系是矿区的主要控矿构造。富碱斑岩体与围岩的北接触带和东接触带是铜钼矿找矿的主攻区域;下奥陶统向阳组碎屑岩和下泥盆统康郎组灰岩中构造破碎带,是找金矿的主要方向。 相似文献
149.
150.
Abstract Economic studies suggest that market leakage rates of greenhouse gas abatement can reach the two-digit percentage range. Although the Marrakesh Accords require Clean Development Mechanism (CDM) projects to account for leakage, most projects neglect market leakage. Insufficient leakage accounting is facilitated by a lack of applicable methods regarding the quantification and attribution of project-related leakage effects. This article proposes a method for attributing CDM-related market leakage effects to individual projects. To this purpose, alternative attribution methods are analysed. We find that project-specific approaches fail to take account of market leakage effects. Consequently, we propose to estimate aggregate market leakage effects and attribute them proportionally to individual projects. We suggest that predetermined commodity-specific leakage factors are applied by project developers to any emission reductions that are associated with a project's leakage-relevant demand or supply changes. This approach is conservative, equitable, incentive-compatible and applicable at manageable costs. 相似文献