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291.
292.
李艳 《成都信息工程学院学报》2007,22(2):274-277
在G-凸空间内得到了一些新的连续选择定理,并利用连续选择定理证明了非紧G-凸空间内及乘积G-凸空间内的重合点定理.这些定理改进并推广了最近文献中的一些已知结果. 相似文献
293.
给出了凸度量空间中渐近拟非扩张映象的Ishikawa型迭代序列收敛于不动点的充要条件,所得结果推广、改进和包含了刘启厚[1]等人的最新成果. 相似文献
294.
本文考虑到干涉仪对电离层中不同尺度不规则性的滤波作用、结合密云米波综合孔径系统、提出了电离层E_(?)层是电离层不规则性影响该系统的主要根源。不规则性的尺度约在700~1000米的范围。再考虑到E_(?)层的漂移运动,提出了文中所描述的模型。用电子计算机进行了E_(?)层对综合射束污染的模拟计算,结果指出:射束主瓣的增益下降约10%,副瓣由13%增大到18%;综合射束在赤经方向出现不对称性,从而引起约0.6秒的赤经误差;射束的边缘处和两个扇形区出现了杂瓣。 相似文献
295.
李留霖 《广东海洋大学学报》2004,24(2):28-32
行政赔偿因果关系的认定,直接关系到国家赔偿法效能的发挥.现实中,行政赔偿之所以陷入困境,其中一个重要原因是行政赔偿因果关系的认定缺乏标准.应从行政管理的规律出发,把握行政法律关系的特征,着眼于行政法未来的发展趋势,从充分发挥行政赔偿的内在功能入手,兼顾国家现实的赔偿能力及当前的法制人文环境,从理论上建立可供司法实践操作的行政赔偿因果关系认定规则. 相似文献
296.
原子钟当前已经发展到很高的水平,它们在空间科学试验中发挥了重要的作用.该文介绍了世界上正在开展的高精度空间钟计划及其对科学测量的意义.对应用空间钟可能进行的某些感兴趣的基础物理测试也进行了描述。 相似文献
297.
Halo coronal mass ejections (HCMEs) are responsible of the most severe geomagnetic storms. A prediction of their geoeffectiveness
and travel time to Earth’s vicinity is crucial to forecast space weather. Unfortunately, coronagraphic observations are subjected
to projection effects and do not provide true characteristics of CMEs. Recently, Michalek (Solar Phys.
237, 101, 2006) developed an asymmetric cone model to obtain the space speed, width, and source location of HCMEs. We applied this technique
to obtain the parameters of all front-sided HCMEs observed by the SOHO/LASCO experiment during a period from the beginning
of 2001 until the end of 2002 (solar cycle 23). These parameters were applied for space weather forecasting. Our study finds
that the space speeds are strongly correlated with the travel times of HCMEs to Earth’s vicinity and with the magnitudes related
to geomagnetic disturbances. 相似文献
298.
The results of unsupervised pattern recognition methods are critically dependent on the measure ofsimilarity used for clustering objects. There is little a priori information available on the relative utilityof various similarity measures. We introduce here an alternative similarity measure based on the metrictensor measure (MTM). Two standard clustering strategies are tested with the proposed similaritymeasure: hierarchical clustering and the K-median method. As data we use the ARCH obsidian data,a data set on Hungarian coal, and trace element data on Hungarian paprika. Differences from theMahalanobis distance measure are described for intraclass relations. 相似文献
299.
Nandita Srivastava 《Journal of Astrophysics and Astronomy》2006,27(2-3):237-242
Geomagnetic super-storms of October and November 2003 are compared in order to identify solar and interplanetary variables
that influence the magnitude of geomagnetic storms. Although these superstorms (DST < -300 nT) are associated with high speed CMEs, their DST indices show large variation. The most intense storm of November
20, 2003 (DSt∼ - 472 nT) had its source in a comparatively small active region and was associated with a relatively weaker, M-class flare,
while the others had their origins in large active regions and were associated with strong X-class flares. An attempt has
been made to implement a logistic regression model for the prediction of the occurrence of intense/superintense geomagnetic
storms. The model parameters (regression coefficients) were estimated from a training data-set extracted from a data-set of
64 geo-effective CMEs observed during 1996–2002. The results indicate that logistic regression models can be effectively used
for predicting the occurrence of major geomagnetic storms from a set of solar and interplanetary factors. The model validation
shows that 100% of the intense storms (-200 nT < DSt < -100 nT) and only 50% of the super-intense (DST < -200 nT) storms could be correctly predicted. 相似文献
300.
《Marine Policy》2015
Justice is an important and contested issue in the governance of fish stocks threatened by overexploitation. This study identifies the notions of justice held by stakeholders of the fishery in Newfoundland, Canada, using qualitative interviews, and interprets these notions in light of established justice theories. The interviews are analysed using inductive and deductive coding. A central result is that inshore fishers are seen as the main claim holders, with a claim to participate and be listened to, and the opportunity to make a living from the fishery. Moreover, rules play an important role in the justice notions of the interview partners, and their justice notions are clearly plural. The stakeholder notions of justice in the Newfoundland fishery resonate with the emphasis on recognition, participation and distribution as important aspects of justice within the environmental justice approach [59-61] (Schlosberg 2004, 2007, 2013). 相似文献