基于最小平方和残差的高阶模糊联合聚类算法     

黄少滨  杨欣欣 《武汉大学学报(信息科学版)》2015,40(2):238-242

目前,多数高阶联合聚类算法属于硬划分方法,不考虑聚簇重叠问题。为了更有效地分析具有重叠聚簇结构的数据,提出了一种基于最小平方和残差的高阶模糊联合聚类算法(MSR-HFCC),该算法将聚类问题转化为最小化模糊平方和残差的优化问题,推导出求解优化问题的隶属度迭代更新公式,设计出聚类过程的迭代算法。实验结果表明,MSR-HFCC算法聚类效果优于目前已有的5种硬划分高阶联合聚类算法。  相似文献   

Identifying gravity anomalies caused by granitic intrusions in Nanling mineral district,China: a multifractal perspective          下载免费PDF全文

Qiuming Cheng  Renguang Zuo  Tianyou Liu  Yufei Xi 《Geophysical Prospecting》2015,63(1):256-270

Several power‐law relationships of geophysical potential fields have been discussed recently with renewed interests, including field value–distance () and power spectrum–wavenumber () models. The singularity mapping technique based on the density/concentration–area (C–A) power‐law model is applied to act as a high‐pass filter for extracting gravity and magnetic anomalies regardless of the background value and to detect the edges of gravity or magnetic sources with the advantage of scale invariance. This is demonstrated on a synthetic example and a case study from the Nanling mineral district, Southern China. Compared with the analytic signal amplitude and total horizontal gradient methods, the singularity mapping technique provides more distinct and less noisy boundaries of granites than traditional methods. Additionally, it is efficient for enhancing and outlining weak anomalies caused by concealed granitic intrusions, indicating that the singularity method based on multifractal analysis is a potential tool to process gravity and magnetic data.  相似文献   

卫星红外遥感技术在我国环保领域中的应用与发展分析     

赵少华  王桥  游代安  姚云军  朱利  随欣欣  张丽娟  李静 《地球信息科学学报》2015,17(7):855-861

本文较为系统地分析了卫星红外遥感技术在我国秸秆焚烧、沙尘、气溶胶、颗粒物、灰霾等大气环境遥感监测,水华、水质参数、水表温度、热污染、核电厂温排水等水环境遥感监测,以及土壤含水量、地表温度、干旱、城市热岛效应等生态环境遥感监测的应用。同时,指出目前国产卫星红外载荷业务化应用程度不高、辐射定标能力不足、应用反演算法原创性不强、地面观测和试验验证能力不足等问题;并提出需大力发展国产红外传感器、提高辐射定标能力、发展国内原创监测算法、建设大型环保应用综合试验场等建议,以促进红外遥感技术在环境保护领域的应用和发展。  相似文献   

基于COSMIC掩星数据分析全球NmF2周年和半年变化特征     

马新欣  焦立果  刘晓灿 《地震地磁观测与研究》2014,35(5):97-100

使用COSMIC掩星提供的NmF2数据,利用傅里叶分析方法,研究全球F2层峰值电子密度的周年和半年分布特征,分析2010年LT12：00 14：00 NmF2周年和半年变化幅度及2008-2011年年平均值变化.结果显示,电离层NmF2周年和半年变化幅度在中高纬地区相对较大;在赤道和低纬地区相对较小,且NmF2以半年变化为主.太阳活动增强期间,NmF2年平均值增大.  相似文献   

全球变化影响下青岛海岸带地理环境的演变   总被引：8，自引：1，他引：7  

杨鸣  夏东兴  谷东起  薛佐  丰爱平 《海洋科学进展》2005,23(3):289-296

在全球变化的影响下,近50多年来青岛海岸带地区的地理环境要素发生了许多超常的变化。其中,年平均气温1991-2002年比20世纪50年代上升了0．94℃,同期最冷月1月平均气温上升了2．18℃,≥10℃的天数由每年207．6d增至218．5d,近海年平均海水温度在20世纪60年代为13．45℃,而1991-2002年为14．20℃,上升了0．75℃。海岸沙滩侵蚀加剧,20世纪90年代以来灵山湾每年蚀退达7m;胶州湾面积由1952年的559km。缩减为2002年的382km^2;滨海漏湖湿地几乎全部消失。由于海岸带气候和水温的变暖使研究区动植物群落发生变化,如茶树从南方引中成功并形成产业,一些本来在长江三角洲地区越冬的鸟类（如大天鹅）已迁至山东半岛越冬;某些生活在温暖海洋中的海洋动物也频现青岛。  相似文献   

资源一号卫星星内粒子探测器与神舟二号X射线探测器对高能电子探测的比较分析   总被引：8，自引：2，他引：6       下载免费PDF全文

邹鸿  肖佐  邹积清  仲维英  郝永强  张东和  马宇倩  王焕玉  徐玉朋  张承模  汪锦州  唐仕奎  梁晓华  徐霁舒  吴中祥 《地球物理学报》2004,47(4):562-570

利用资源一号卫星和神舟二号留轨舱上搭载的高能粒子探测设备对2001年2～6月同一时段内的资料进行了对比分析. 神舟二号飞船X射线探测器的观测结果反映的空间高能电子的分布, 表明在400km的较低高度上, 地理纬度40°附近以及SAA地区也可以观测到数百keV的高能电子. 资源一号卫星的探测结果显示了在800km高度附近, 同一时段内若干兆电子伏特的高能电子的全球分布. 后者出现的最低地理纬度和相应的经度位置则和前者是一致的, 说明两个高度上高能粒子的分布仍然都受地磁场控制, 粒子主要来源于地球辐射带. 资源一号卫星高能粒子探测器的能挡与神舟二号飞船X射线探测器的能挡不同, 彼此可以较好地补充. 但由于神舟二号轨道倾角较低, 全面的对比也受到一定的局限, 在进一步深入分析现有资料的同时, 可以在本文基础上设计更好的联合探测方案.  相似文献   

A Research on the Gravity Deformation of Delingha 13.7m Telescope     

Ying-Xi Zuo  Yang Li  Ji-Xian Sun  Ji Yang  Jing-Jing Li  Ye Xu  Deng-Yun He  Qin-Hong Fan  Sheng-Hong Fan 《Chinese Astronomy and Astrophysics》2011,35(4):439-446

Based on digital photogrammetric measurements, the antenna panels of the Delingha 13.7m radio telescope are adjusted to make the main dish have an optimal paraboloidal surface at the elevation of 52°, thus the overall antenna efficiency is optimized for different observing elevations. Observations indicate that the aperture efficiency of the telescope has been improved approximately twice in comparison with the antenna panels adjusted on the basis of theodolite measurements. According to the results of the measurements at different elevations, the models of antenna gravity deformation are built, including the displacement and tilt angle of the subreflector, as well as the focal length and surface error of the main reflector, as functions of elevation angle. In the process of modeling the gravity deformation of the main dish, instead of the direct calculation method, the least square fitting on the measured surface errors at different elevation angles is adopted, in order to reduce the effect of measurement errors on the accuracy of the model.  相似文献   

降低交叉反应的鱼类病原菌检测抗体芯片初步研究   总被引：1，自引：0，他引：1  

王欣欣  绳秀珍  战文斌 《海洋湖沼通报》2013,(1):23-28

采用菌体吸附法对海豚链球菌(Streptococcus iniae)、迟缓爱德华氏菌(Edwardsiella tarda)、鳗弧菌(Vibrio anguillarum)、杀鲑气单胞菌(Aeromonas salmonicida)、荧光假单胞菌(Psedomonas fluo-rescens)和海洋分支杆菌(Mycobacterium marinum)6种养殖鱼类病原菌的兔抗血清进行吸附,以减小抗血清与其它菌株的交叉反应;吸附纯化后的抗体作为捕获抗体构建了病原菌检测抗体芯片。实验结果显示,与未经过吸附的纯化抗血清构建的抗体芯片相比,血清吸附实验能有效减少交叉反应,降低抗体的非特异性吸附,提高细菌检测的特异性。同时,以迟缓爱德华氏菌为例,采用吸附纯化后抗体制备的抗体芯片检测人工感染迟缓爱德华氏菌和自然发病的牙鲆,均观察到迟缓爱德华氏菌的特异性显色反应,得到了较理想的检测结果。本文结果说明优化后的病原菌检测抗体芯片可用于水产养殖鱼类常见的上述6种细菌性疾病的有效检测。  相似文献   

核电厂地震PSA方法研究探讨     

付陟玮  陈妍  张东辉  张春明  左嘉旭  宋维 《国际地震动态》2012,(12):24-30

首先回顾了地震概率安全评价(Seismic Probability Safety Assessment,SPSA)方法的发展历史及应用现状;然后基于SPSA的要素,研究了SPSA方法中需要解决的主要问题,重点是地震易损性分析,并根据SPSA的任务描述SPSA流程,主要探讨电厂走访和继电器评价的方法;最后结合我国概率安全评价(Probability Safety Assessment,PSA)的研究进展、SPSA的基础等实际状况,提出适合我国的SPSA实施路线的建议,以保障核电站地震情况下的安全.  相似文献   

Research on the impact assessment of urbanization on air environment with urban environmental entropy model: a case study   总被引：2，自引：2，他引：0  

Qingsong Wang  Xueliang Yuan  Chunyuan Ma  Zhen Zhang  Jian Zuo 《Stochastic Environmental Research and Risk Assessment (SERRA)》2012,26(3):443-450

A new concept of urban environmental entropy was introduced to investigate the effect of urbanization on air environment considering the fact that rapid development of urbanization may have negative influence on the whole air environment system. The urban environmental entropies which were built based on the generalized thermodynamic entropy and the generalized statistic entropy, respectively. These two entropy models have been used to analyze the relationship between the development of urbanization and air environment. The negative entropy flow mechanism was proposed to reveal the advantages and approaches of regional cities in improving air environment system. A case study on 17 cities in Shandong Province of China showed that the values of urban environmental entropy were negative in most cities from 2001 to 2008, which implies that there is a positive correlation between the development of urbanization and air environment and that is a negative entropy development level in Shandong Province of China. In 2008, the urbanization of Qingdao city and Jinan city improved their air environments. Moreover, restraints for both cities in air environment improvement were recognized according to the analysis of negative entropy flow mechanism.  相似文献