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831.
尹琦 《南京气象学院学报》2010,(4):324-327
提出了一种基于模糊方法并考虑用户评价属性(相似度和可信度)的Web选择算法,从Web服务质量数据来源角度对服务质量的属性进行了分类和计算.对非功能质量属性,使用模糊控制的度量方法,将非功能属性值转换成0~1之间的实数值.使用反馈相似度和可信度相结合的方法,将最终的推荐权值推荐给用户.该方法的提出有助于提高Web服务选择结果的准确性. 相似文献
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Mohammadmahdi Rezaei Yousefi Babak Salehi Kasmaei Abdolhossein Vahabie Caro Lucas Babak Nadjar Araabi 《Solar physics》2009,258(2):297-318
Various phenomena with solar origin and their mutual dependence must be studied in order to predict behaviors in solar – terrestrial
system. Linear statistical methods prevalent in analyzing natural systems may not be able to detect nonlinear dependencies
among solar and geomagnetic processes. When relations, whether linear or nonlinear, between indices and their changes over
time are revealed, better predictions can be made through appropriate modeling techniques. Selection of nonredundant input
variables to build suitable models for prediction of solar and geomagnetic activity is of utmost importance. Mutual information
is a tool that is capable of capturing all dependencies for detecting nonlinear relations and selecting the best subset of
input variables by means of an applicable algorithm that maximizes information about the output and minimizes the shared information
between inputs. High generalization power and improved interpretability of the selected inputs are the consequences of this
analysis. 相似文献
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Based on the daily runoff data from 20 hydrological stations above the Bengbu Sluice in the Huaihe River Basin during 1956-2010, run test, trend test and Mann-Kendall test are used to analyze the variation trend of annual maximum runoff series. The annual maximum series (AM) and peaks over threshold series (POT) are selected to describe the extreme distributions of generalized extreme value distribution (GEV) and generalized Pareto distribution (GPD). Temporal and spatial variations of extreme runoff in the Huaihe River Basin are analyzed. The results show that during the period 1956-2010 in the Huaihe River Basin, annual maximum runoff at 10 stations have a decreasing trend, while the other 10 stations have an unobvious increasing trend. The maximum runoff events almost occurred in the flood period during the 1960s and 1970s. The extreme runoff events in the Huaihe River Basin mainly occurred in the mainstream of the Huaihe River, Huainan mountainous areas, and Funiu mountainous areas. Through Kolmogorov-Smirnov test, GEV and GPD distributions can be well fitted with AM and POT series respectively. Percentile value method, mean excess plot method and certain numbers of peaks over threshold method are used to select threshold, and it is found that percentile value method is the best of all for extreme runoff in the Huaihe River Basin. 相似文献
836.
为了认知影响须浮鸥(Chlidonias hybridus)营巢的主要环境因素,于2011年6~7月,采用直接观察法和样方法在大庆龙凤湿地自然保护区内对须浮鸥的巢区进行了调查研究.在本次调查中共发现须浮鸥巢73个,逐巢进行了常规测量,并对须浮鸥巢址及附近无巢对照区域的生境进行了调查.主成分分析和独立样本t检验的结果表明,须浮鸥属于集群营巢,而影响须浮鸥巢址选择的主要因素依次为巢下水深、巢距植物距离、巢周明水面积、植物高度、植物密度和巢距干扰源距离.其中,前3个因素影响须浮鸥生境中食物的供给条件,后3个因素影响须浮鸥巢的隐蔽条件.须浮鸥选择巢址的条件是能提供丰富食物且具有较好隐蔽条件的生境. 相似文献
837.
SUI Haigang HUA Li ZHAO Haitao ZHANG Yongli 《地球空间信息科学学报》2005,8(4):262-268
An effective strategy and framework that adequately integrate the automated and manual processes for fast cartographic sounding selection is presented. The important submarine topographic features are extracted for important soundings selection, and an improved “ influence circle” algorithm is introduced for sounding selection. For automatic configuration of soundings distribution pattern, a special algorithm considering multi-factors is employed. A semi-automatic method for solving the ambiguous conflicts is described. On the basis of the algorithms and strategies a system named HGIS for fast cartographic sounding selection is developed and applied in Chinese Marine Safety Administration Bureau (CMSAB). The application experiments show that the system is effective and reliable. At last some conclusions and the future work are given. 相似文献
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