基于人工免疫网络的在线核聚类算法     

程国峰  陈诗平  许家珆 《成都信息工程学院学报》2009,24(3)

针对核聚类算法与免疫网络聚类算法的不足,将免疫网络机制与核理沦相结合,通过用核距离函数代替欧拉距离函数,设置反映抗体识别抗原数量的权重和引入人工免疫网络机制等解决样本类边界模糊和类间数据密度分布不均匀问题.最后通过人工数据集和lRIS数据集上的仿真试验,验证了算法的有效性.  相似文献   

土地利用数据库中大比例尺面状道路数据缩编研究     

刘一宁  蓝秋萍  费立凡 《武汉大学学报(信息科学版)》2012,37(9):1108-1111,1125

根据建立大比例尺多级土地利用数据库的需要,在进行面状道路数据综合时,对道路进行分类,保留需保持面状的道路面,将不符合要求的道路从网络状道路面中分离出来,并根据需要予以转线或删除,形成新的小比例尺的线面混合道路数据。同时,将删除的道路面分割并归并进相邻图斑,以保证土地数据面状连续的特点。  相似文献   

Shifting borders,shifting center: hedging-out uncertainty in west Jerusalem’s urban core     

《Urban geography》2012,33(10):1422-1442

ABSTRACT

This article argues that contested cities are inherently characterized by uncertainty and uses the interconnections between conflict, uncertainty and urban planning as a new analytical framework for investigating conflict cities. In the contested city of Jerusalem, geopolitical uncertainty stems from the Israeli occupation over East Jerusalem. Focusing on recent urban regeneration plans for West Jerusalem’s city center, the article explores how the municipality locates, plans and imagines the city center when the city’s external and internal boundaries are contested and unfixed. A two-tier analysis is employed. First, a historical analysis shows that the “city center”, as defined by authorities, is an unfixed locale that shifts in concurrence with shifts in the city’s boundaries. Then, a geopolitical analysis shows that by shifting the city center’s boundaries, the Israeli authorities decouple the city’s economic development (in the west) from Israel’s continuing ethno-national policies (in the east).  相似文献   

Arbitrary Lagrangian–Eulerian method for dynamic analysis of geotechnical problems     

M. Nazem  J.P. Carter  D.W. Airey 《Computers and Geotechnics》2009

In this paper an arbitrary Lagrangian–Eulerian (ALE) method to solve dynamic problems involving large deformation is presented. This ALE method is based upon the operator-split technique in which the material displacements and mesh displacements are uncoupled. A brief history of the ALE method is first presented and then special issues such as time-stepping, mesh refinement, energy absorbing boundaries, dynamic equilibrium checks and remapping of state variables are explained. The ALE method and the updated-lagrangian (UL) method are then used to analyse some geotechnical problems to examine the significance of inertia effects, large deformation and contact mechanics. The results show the efficiency of the ALE method for solving dynamic geotechnical problems involving large deformation.  相似文献   

A diagnostic calculation of the circulation in the upper and middle layers of the Luzon Strait and the northern South China Sea during March 1992   总被引：2，自引：0，他引：2  

Yaochu Yuan  Guanghong Liao  Chenghao Yang 《Dynamics of Atmospheres and Oceans》2009,47(1-3):86-113

Wind data from NCEP and hydrographic data obtained during 8–27 March 1992 have been used to compute circulation in the Luzon Strait and the northern South China Sea using three-dimensional diagnostic models with a modified inverse method. Numerical results are as follows: the main Kuroshio is located above 800 m levels. It has two intrusive branches of the Kuroshio in the areas above 400 m. One part intrudes anti-cyclonically northwestward, then flows through the area above 200 m southwest of Taiwan and into the Taiwan Strait. The other part intrudes westward and flows cyclonically in the areas north of the cyclonic eddies, then flows southward through the southern boundary of the region. The net westward volume transport (VT) through Section at 120°15′E between Luzon Island and Taiwan Island is about 3.0 Sv, net northward VT through northern boundaries into the Taiwan Strait is about 1.4 Sv and net southward VT through southern boundaries is about 1.6 Sv, which finally flows into the Karimata and Mindoro Straits. In the areas above 400 m east of 117°15′E, the circulation is mainly dominated by the basin-scale cyclonic gyre, which consists of two cyclonic eddies. However, in the areas below 400 m east of 119°00′E, the circulation is mainly dominated by basin-scale anti-cyclonic gyre. The joint effect of baroclinity and relief and interaction between wind stress and relief are important in different area respectively for the pattern of the depth-averaged flow across contours of fH⁻¹.  相似文献   

关于共反射面元叠加方法在实际应用中的一些思考   总被引：14，自引：7，他引：7       下载免费PDF全文

杨锴  马在田 《地球物理学进展》2005,20(1):12-16

共反射面元（Common Reflection Surface=CRS）叠加是一种特殊的零偏移距成像方法,实践中它具有独立于宏观速度模型和完全数据驱动实现的鲜明特色,CRS叠加理论认为在得到高质量的零偏移距剖面的同时,还可以得到三个有用的波场属性参数剖面反演宏观速度模型,CRS叠加剖面之后的叠后深度偏移质量将超过叠前深度偏移.虽然CRS叠加倡导的成像方式和承诺的上述理想境界带来了全新的启示,但是实践中这些特色同样带来了令人困扰的问题,为此我们提出了倾角分解CRS叠加方法解决这些问题.本文即是作者通过上述实践之后对CRS叠加方法形成的一些思考和总结.  相似文献   

Assessment of digital camera-derived vegetation indices in quantitative monitoring of seasonal rice growth   总被引：4，自引：0，他引：4  

Toshihiro Sakamoto  Michio Shibayama  Akihiko Kimura  Eiji Takada 《ISPRS Journal of Photogrammetry and Remote Sensing》2011,66(6):872-882

A commercially available digital camera can be used in a low-cost automatic observation system for monitoring crop growth change in open-air fields. We developed a prototype Crop Phenology Recording System (CPRS) for monitoring rice growth, but the ready-made waterproof cases that we used produced shadows on the images. After modifying the waterproof cases, we repeated the fixed-point camera observations to clarify questions regarding digital camera-derived vegetation indices (VIs), namely, the visible atmospherically resistant index (VARI) based on daytime normal color images (RGB image) and the nighttime relative brightness index (NRBI_NIR) based on nighttime near infrared (NIR) images. We also took frequent measurements of agronomic data such as plant length, leaf area index (LAI), and aboveground dry matter weight to gain a detailed understanding of the temporal relationship between the VIs and the biophysical parameters of rice. In addition, we conducted another nighttime outdoor experiment to establish the link between NRBI_NIR and camera-to-object distance. The study produced the following findings. (1) The customized waterproof cases succeeded in preventing large shadows from being cast, especially on nighttime images, and it was confirmed that the brightness of the nighttime NIR images had spatial heterogeneity when a point light source (flashlight) was used, in contrast to the daytime RGB images. (2) The additional experiment using a forklift showed that both the ISO sensitivity and the calibrated digital number of the NIR (cDN_NIR) had significant effects on the sensitivity of NRBI_NIR to the camera-to-object distance. (3) Detailed measurements of a reproductive stem were collected to investigate the connection between the morphological feature change caused by the panicle sagging process and the downtrend in NRBI_NIR during the reproductive stages. However, these agronomic data were not completely in accord with NRBI_NIR in terms of the temporal pattern. (4) The time-series data for the LAI, plant length, and aboveground dry matter weight could be well approximated by a sigmoid curve based on NRBI_NIR and VARI. The results confirmed that NRBI_NIR was more sensitive to all of the agronomic data for overall season, including the early reproductive stages. VARI had an especially high correlation with LAI, unless yellow panicles appeared in the field of view.  相似文献   

地应力测量与监测技术实验研究——SinoProbe-06项目介绍   总被引：2，自引：0，他引：2  

陈群策  李宏  廖椿庭  吴满路  崔效锋  杨树新 《地球学报》2011,32(Z1):113-124

固体地壳的应力状态是地壳的最重要的性质之一.地壳表面和内部发生的各种构造现象及其伴生的各种地质灾害都与地壳应力的作用密切相关.地应力测量与监测不仅为深入认识地震的孕育和发生机制,进而为强震预测提供重要的科学依据,而且也是地球动力学基础研究的重要组成部分,此外,还将为国家重大工程建设,如深埋隧道、水电工程、深部能源开采、...  相似文献   

非零偏VSP多波波场分离方法     

丁拼搏  李录明  邓颖华 《物探化探计算技术》2011,33(5):477-482,461

这里研究了中值滤波法在波场分离中的应用,分析了中值滤波中参数的选择对分离效果的影响,并应用中值滤波法分离上行波、下行波.同时,对VSP中纵波、横波的偏振方向进行了分析,利用上行波、下行波振幅矢量关系对VSP记录进行纵波、横波分离,得到良好的分离效果.理论模型处理结果表明,应用中值滤波分离上行波、下行波,再利用偏振关系分...  相似文献   

Multipolar elastic fields in homogeneous isotropic media by higher-order ray approximations     

V. Vavry&#;uk  K. Yomogida 《Geophysical Journal International》1995,121(3):925-932

  相似文献