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基于泊松退役假定的中国城镇资本测算
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作者 金剑 王超 《统计与决策》 CSSCI 北大核心 2024年第5期160-165,共6页
传统资本测算所依赖的钟型退役假定存在连续型函数与离散型变量之间不匹配、连续型函数的唯一确定困难等问题,并因此可能影响测算结果的准确性与可靠性。文章基于永续盘存法,提出与资产役龄这一离散型变量相契合的泊松退役假定,并根据... 传统资本测算所依赖的钟型退役假定存在连续型函数与离散型变量之间不匹配、连续型函数的唯一确定困难等问题,并因此可能影响测算结果的准确性与可靠性。文章基于永续盘存法,提出与资产役龄这一离散型变量相契合的泊松退役假定,并根据资产在不同产业间的分布、工作内容和实现方式将固定资产分为九类,对中国城镇资本进行测算。结果显示:1995—2021年中国城镇固定资产的资本存量总额、资本存量净额和生产性资本存量单调递增;全行业和第二、三产业的资本投入趋势比较接近,整体都表现出“减—增—减”的变化趋势,第一产业的资本投入波动明显强于全行业和第二、三产业。 展开更多
关键词 资本测算 永续盘存法 退役函数
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基于泊松小波径向基函数融合多源数据的局部重力场建模 被引量:17
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作者 吴怿昊 罗志才 周波阳 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2016年第3期852-864,共13页
融合多源数据的高精度、高分辨率的局部重力场建模是物理大地测量学的前沿和热点问题.本文研究了基于径向基函数融合多源数据的局部重力场建模方法,利用Monte-Carlo方差分量估计实现了不同类型的观测数据的合理定权,引入了最小标准差法... 融合多源数据的高精度、高分辨率的局部重力场建模是物理大地测量学的前沿和热点问题.本文研究了基于径向基函数融合多源数据的局部重力场建模方法,利用Monte-Carlo方差分量估计实现了不同类型的观测数据的合理定权,引入了最小标准差法确定基函数的适宜网络,分析了地形因素对于基函数网络确定及局部重力场建模精度的影响.以泊松小波基函数为构造基函数,结合残差地形模型,融合实测的陆地重力异常、船载重力异常及航空重力扰动数据构建了局部区域陆海统一的似大地水准面模型.研究结果表明:引入残差地形模型平滑了地形质量引入的高频扰动信号,简化了基函数的网络设计;并提高了重力似大地水准面的精度,平原地区其精度提高了4mm,地形起伏较大的山区其精度提高了约5cm.总体而言,基于"三步法"构建的局部重力似大地水准面在荷兰、比利时及德国相关区域,其精度分别达到1.12cm、2.80cm以及2.92cm. 展开更多
关键词 径向基函数 小波基函数 残差地形模型 局部重力场建模 重力似大地水准面
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混合高斯/泊松最大似然函数下的CBCT图像重建 被引量:10
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作者 郑蓉珍 赵芳 +1 位作者 李波 田昕 《光学精密工程》 EI CAS CSCD 北大核心 2020年第2期457-464,共8页
如何在复杂噪声条件下提升锥形束计算机断层扫描成像(Cone Beam Computed Tomography,CBCT)图像重建质量,对于CBCT系统而言是非常重要的。本文提出了一种混合高斯/泊松最大似然函数下的CBCT图像重建方法。首先研究了适宜于描述混合高斯... 如何在复杂噪声条件下提升锥形束计算机断层扫描成像(Cone Beam Computed Tomography,CBCT)图像重建质量,对于CBCT系统而言是非常重要的。本文提出了一种混合高斯/泊松最大似然函数下的CBCT图像重建方法。首先研究了适宜于描述混合高斯/泊松噪声环境下的CBCT图像重建模型,它包含一个基于混合高斯/泊松最大似然函数的保真项和一个基于三维全变分正则化方法的约束项。保真项用于约束在混合噪声模型下重建结果与观测值尽可能的相近,约束项用于噪声去除并要求尽可能较好地保留图像的边缘与细节信息。进一步通过可分离近似方法和扩展拉格朗日方法对上述模型进行求解。最后通过仿真数据和真实数据对算法的有效性进行了验证,实验结果表明:仿真结果相对于其他方法而言,PSNR最高可以提升2.1 dB;从主观视觉而言,本文方法在噪声环境下具有较好的图像重建质量。因此,本文方法可以被广泛应用于各种低剂量条件下的CBCT图像重建中。 展开更多
关键词 CBCT 混合高斯/最大似然函数 全变分正则化 图像重建
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基于航空重力梯度数据重建高分辨率局部重力场的径向基函数方法
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作者 吴怿昊 何秀凤 +3 位作者 罗志才 吴云龙 许闯 宛家宽 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2024年第5期1913-1926,共14页
基于径向基函数技术,研究了利用航空重力梯度数据重建局部重力场模型的方法,建立了泊松小波径向基函数和航空重力梯度张量之间的解析关系.以频率域变换和等效源方法为例讨论了不同梯度分量转换方法对重力场建模的影响,分析了基函数埋深... 基于径向基函数技术,研究了利用航空重力梯度数据重建局部重力场模型的方法,建立了泊松小波径向基函数和航空重力梯度张量之间的解析关系.以频率域变换和等效源方法为例讨论了不同梯度分量转换方法对重力场建模的影响,分析了基函数埋深深度对建模的影响.以澳大利亚珀斯Kauring试验场为例,采用实测航空重力梯度垂直分量构建了高分辨率重力场模型.结果表明,局部地形扰动对建模的影响较大,即使在平原或丘陵区域,也要考虑其影响.此外,不同梯度分量转换方法对于区域重力异常恢复的影响较小.再者,基函数埋深深度对建模影响较大;相比于采用重力数据建模而言,基于航空重力梯度数据求解时,基函数的适宜埋深深度更浅.联合航空重力梯度数据求解能显著提高重力场模型在高频和甚高频波段的分辨率和精度.与实测航空重力数据对比表明,利用航空重力梯度数据可构建分辨率约为0.15 km、精度优于1 mGal的重力场模型. 展开更多
关键词 航空重力梯度测量 垂直重力梯度 小波径向基函数 局部重力场建模 航空重力数据
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Poisson型密度函数的L_p逼近特征
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作者 陈文忠 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 1997年第1期1-9,共9页
利用Polya基函数构造Poisson型密度函数,并研究密度函数在Lp-范数下的逼近特征.
关键词 Polya基函数 密度函数 型密度函数 Lp逼近
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L^p{(0,π),dm_(λ,μ)(θ)}空间的正交展开
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作者 余纯武 《北京师范大学学报(自然科学版)》 CAS CSCD 北大核心 1999年第3期293-297,共5页
对于空间LP{(0,π),dmλ,μ(θ)},利用极大函数控制讨论了由广义的Gegenbauer多项式定义的Poisson函数的收敛问题,并且得到了调和函数对Poisson积分的刻画.
关键词 调和函数 收敛 积分 L^P空间 泊松函数
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联合多代卫星测高和多源重力数据的局部大地水准面精化方法 被引量:7
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作者 吴怿昊 罗志才 《地球物理学报》 SCIE EI CAS CSCD 北大核心 2016年第5期1596-1607,共12页
本文研究了基于泊松小波径向基函数融合多代卫星测高及多源重力数据精化大地水准面模型的方法.分别以沿轨垂线偏差和大地水准面高高差作为卫星测高观测量,研究了使用不同类型测高数据对于大地水准面建模精度的影响.针对全球潮汐模型在... 本文研究了基于泊松小波径向基函数融合多代卫星测高及多源重力数据精化大地水准面模型的方法.分别以沿轨垂线偏差和大地水准面高高差作为卫星测高观测量,研究了使用不同类型测高数据对于大地水准面建模精度的影响.针对全球潮汐模型在浅水区域及部分开阔海域精度较低的问题,引入局部潮汐模型研究了不同潮汐模型对于大地水准面的影响.数值分析表明:相比于使用沿轨垂线偏差作为测高观测量,基于沿轨大地水准面高高差解算得到的大地水准面模型的精度更高,特别是在海域区域,其精度提高了2.3cm.由于使用沿轨大地水准面高高差作为测高观测量削弱了潮汐模型长波误差的影响,采用不同潮汐模型对大地水准面解算的影响较小.总体而言,船载重力及测高观测数据在海洋重力场的确定中呈现互补性关系,联合两类重力场观测量可以提高局部重力场的建模精度. 展开更多
关键词 卫星测高 小波径向基函数 沿轨大地水准面高高差 局部潮汐模型 局部大地水准面精化
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广义残差地形模型及其在局部重力场逼近中的应用 被引量:1
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作者 吴怿昊 罗志才 周波阳 《测绘学报》 EI CSCD 北大核心 2016年第5期531-537,559,共8页
研究了残差地形模型中的非调和性问题,比较了基于棱柱体和球冠体的积分模型,提出了基于球冠体积分的广义残差地形模型。以泊松小波径向基函数为构造基函数,结合广义残差地形模型,融合多源实测重力数据构建了局部区域重力场模型。研究结... 研究了残差地形模型中的非调和性问题,比较了基于棱柱体和球冠体的积分模型,提出了基于球冠体积分的广义残差地形模型。以泊松小波径向基函数为构造基函数,结合广义残差地形模型,融合多源实测重力数据构建了局部区域重力场模型。研究结果表明:基于棱柱体积分的残差地形模型精度较低,在山区可能引入毫伽级以上的误差,建议采用更为接近真实地形表面的球冠体积分模型。相比于原始的残差地形模型,基于球冠体积分的广义残差地形模型能更为精确地逼近局部重力场模型中地形因素引起的高频效应。 展开更多
关键词 残差地形模型 调和改正 小波径向基函数 似大地水准面 局部重力场建模
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融合多源数据的局部重力场建模中线性化误差的研究
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作者 吴怿昊 罗志才 《大地测量与地球动力学》 CSCD 北大核心 2016年第6期476-480,共5页
引入高阶重力场模型作为参考场,削弱局部重力场逼近中线性化误差的影响。以实测的陆地重力异常、船载重力异常及航空重力扰动为基础数据,基于泊松小波径向基函数分析不同参考场对局部重力场逼近的影响。结果表明,引入高阶全球重力场模... 引入高阶重力场模型作为参考场,削弱局部重力场逼近中线性化误差的影响。以实测的陆地重力异常、船载重力异常及航空重力扰动为基础数据,基于泊松小波径向基函数分析不同参考场对局部重力场逼近的影响。结果表明,引入高阶全球重力场模型代替GRS80参考椭球正常场作为参考场,能更为准确地逼近真实的重力场,有效削弱线性化误差的影响。相比于基于GRS80正常场构建的似大地水准面模型,基于DGM1S重力场模型为参考场构建的似大地水准面的精度,在地形起伏较大的德国、英国及挪威区域分别提高了1.5mm、3.3mm和9.0mm。 展开更多
关键词 局部重力场建模 线性化误差 小波基函数 全球重力场模型
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Inventory control model based on external and interior reverse logistics 被引量:1
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作者 董景峰 王刚 +1 位作者 吕民 高国安 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第5期717-722,共6页
To improve the inventory control strategy for enterprise and optimize inventory control parameters of existing external and interior reverse logistics, a multi-resource inventory control model is proposed to better si... To improve the inventory control strategy for enterprise and optimize inventory control parameters of existing external and interior reverse logistics, a multi-resource inventory control model is proposed to better simulate the logistics fact, which is aimed at periodic inventory checking and pull mode of inventory control strategy, based on the return product arrival time obeying Poisson distribution, the return product employing lotsize process and the nonzero lead time of manufaeturinge/remanufacturing. The rational cost function with multiple constraints is employed to describe the inventory model. The genetic algorithm is employed to solve the inventory cost function to obtain the optimal solution of inventory checking periods, safe inventory point, product lot-sizes and process lot-sizes of return product. An example is presented to prove the feasibility and validity of the proposed method. Moreover, the influence of manufacturing/remanufacturing lead time and reuse rate of return production on the inventory control strategy of enterprise is analyzed. 展开更多
关键词 reverse logistics inventory control periodic checking lead time
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Study of Crustal Thickness and Poisson Ratio of Hebei and Its Adjacent Areas by Teleseismic Receiver Function
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作者 Gong Meng Zhang Suxing +3 位作者 Luo Yan Zeng Xiangfang Jia Lifeng Liu Li 《Earthquake Research in China》 CSCD 2015年第3期331-340,共10页
We collected waveforms of a teleseismic event which occurred from January 2007 to October 2011 from 174 broadband seismic stations deployed in Hebei and its adjacent areas. Using the H-k stacking method,the average th... We collected waveforms of a teleseismic event which occurred from January 2007 to October 2011 from 174 broadband seismic stations deployed in Hebei and its adjacent areas. Using the H-k stacking method,the average thickness and Poisson's ratio of the crust are acquired. In order to obtain reliable receiver functions, the broadband seismograms of 488 teleseismic earthquakes occurring in the epicentral distance range from 30° to 90° with magnitudes larger than Mb6. 0 are collected. The results show that crustal thickness have conspicuous lateral heterogeneity and have good correlation to the regional geological tectonic features. Poisson ratio's value is equated with the global models estimates which fluctuate at about 0. 25. Crustal thickness has positive correlation to the topography and the Taihang Mountains form the transition zone of thick and thin crustal thickness. There is an obvious difference in crustal thickness beneath the north and south of the Shanxi earthquake zone and the Poisson ratio of Datong,Ningwu and Anze basins is greater than 0. 3. The crustal thickness beneath the Zhang-Bo( Zhangjiakou-Bohai Sea)earthquake zone decreases from west to north and its Poisson ratio shows conspicuous lateral heterogeneity. The thin crust and low Poisson ratio in the Huabei( North China)basin may correlate with the delamination of the North China craton. 展开更多
关键词 Hebei and its adjacent areas Receiver function H-k stacking Poisson ratioCrustal thickness
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High-speed corner detection based on fuzzy ID3 decision tree
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作者 段汝娇 赵伟 +1 位作者 黄松岭 郝宽胜 《Journal of Central South University》 SCIE EI CAS 2012年第9期2528-2533,共6页
A high-speed comer detection algorithm based on fuzzy ID3 decision tree was proposed. In the algorithm, the Bresenham circle with 3-pixel radius was used as the test mask, overlapping the candidate comers with the nuc... A high-speed comer detection algorithm based on fuzzy ID3 decision tree was proposed. In the algorithm, the Bresenham circle with 3-pixel radius was used as the test mask, overlapping the candidate comers with the nucleus. Connected pixels on the circle were applied to compare the intensity value with the nucleus, with the membership function used to give the fuzzy result. The pixel with maximum information gain was chosen as the parent node to build a binary decision tree. Thus, the comer detector was derived. The pictures taken in Fengtai Railway Station in Beijing were used to test the method. The experimental results show that when the number of pixels on the test mask is chosen to be 9, best result can be obtained. The comer detector significantly outperforms existing detector in computational efficiency without sacrificing the quality and the method also provides high performance against Poisson noise and Gaussian blur. 展开更多
关键词 comer detector fuzzy ID3 algorithm decision tree computation efficiency REAL-TIME
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Statistics and Correlation Properties of Diamagnetic High Rydberg Hydrogen Atom
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作者 康帅 陈昌永 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第1期105-109,共5页
The spectra of Rydberg hydrogen atom in magnetic fields have been calculated using linear variational method with B-splines basis functions [Acta Phys. Sin. 55 (2006) 3380]. Based on these calculations we have done... The spectra of Rydberg hydrogen atom in magnetic fields have been calculated using linear variational method with B-splines basis functions [Acta Phys. Sin. 55 (2006) 3380]. Based on these calculations we have done some statistics analysis about the high Rydberg energy levels. The nearest-neighbor energy spacing distribution and the 3-statistics have been shown about diamagnetic Rydberg hydrogen atom with the magnetic field being 0.6 T and 6 T. The phenomena of multiply crossing, multiply anti-crossing, and the mixed of crossing and anti-crossing of energy levels have appeared in this paper. For both cases, in range of lower energy, the energy 1evel statistics properties close to Poisson distribution. With the increasing of the energy, the energy level statistics properties are away to Poisson distribution and tend to Wigner distribution step by step. 展开更多
关键词 B-SPLINES Rydberg hydrogen atom diamagnetic spectra quantum chaos energy level statistics linear variational method
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The Crustal Thickness and Poissons Ratio Distribution in Guangdong and Its Adjacent Areas
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作者 Shen Yusong Kang Ying Xu Guoming 《Earthquake Research in China》 CSCD 2016年第1期108-118,共11页
Based on the teleseismic waveform data recorded by 82 permanent broadband stations in Guangdong Province and its adjacent areas including Fujian, Jiangxi, Hunan, Guangxi, Hainan and Taiwan, we calculate body wave rece... Based on the teleseismic waveform data recorded by 82 permanent broadband stations in Guangdong Province and its adjacent areas including Fujian, Jiangxi, Hunan, Guangxi, Hainan and Taiwan, we calculate body wave receiver functions under all stations, and obtain the crustal thickness and average Poisson's ratio beneath all stations by the H-K stacking-search method of receiver function. The results show that the crustal thickness with an average thickness of 29. 5km in Guangdong Province and its adjacent areas ranges between 26. 8km and 33. 6kin and gradually thins from northwest to southeast. The crustal thickness in the Zhujiang Delta, western Guangdong, Nanning and Nan'ao areas is relatively thinner and ranges between 25. 0km and 28. 0km. The minimum crustal thickness is about 26km beneath Wengtian, Hainan and the Zhanjiang zone and Shangchuan Island in Guangdong. The crustal thickness in the zones of Mingxi, Fujian and Yongzhou, Hunan is thicker and varies between 31.0km and 34.0km. The distribution of Poisson's ratio in our study region ranges between 0.20 and 0. 29. Poisson's ratios in Southeast Hainan, the coastal areas of East Guangdong and West Fujian and the South Jiangxi have distinctly higher values than in others. It suggests that the various geothermal fields located in these areas have high heat flow values. The distribution of crustal thickness and Poisson's ratio has an obvious block feature and may be related to the distribution of faults and historical earthquakes. 展开更多
关键词 Receiver function Crustal thickness Poisson's ratio
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一种基于动态局部密度和聚类结构的聚类算法 被引量:2
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作者 卢建云 张蔚 李林 《山东大学学报(工学版)》 CAS CSCD 北大核心 2022年第2期118-127,共10页
为提高逆k最近邻在度量局部密度时的区分度,提出动态逆k最近邻概念。利用泊松概率密度函数拟合逆k最近邻分布,并计算累积动态逆k最近邻局部密度;基于动态局部密度对数据对象进行排序,利用逆k最近邻域扩展算法生成聚类结构;依据动态局部... 为提高逆k最近邻在度量局部密度时的区分度,提出动态逆k最近邻概念。利用泊松概率密度函数拟合逆k最近邻分布,并计算累积动态逆k最近邻局部密度;基于动态局部密度对数据对象进行排序,利用逆k最近邻域扩展算法生成聚类结构;依据动态局部密度和欧式距离设计聚类决策图,根据决策图找出聚类结构中的类间间断点,利用间断点将聚类结构直接划分成独立的类簇。将本研究提出的聚类结构划分聚类(cluster structure partition clustering, CSPC)算法与DBSCAN、DPC和RNN-DBSCAN算法在人工和真实数据集上进行试验对比,CSCP在人工和真实数据集上的评价指标F1平均分别提高8.8%和8.2%,评价指标标准互信息平均分别提高11.6%和7.3%。试验结果表明CSPC算法取得了更好的聚类结果。 展开更多
关键词 动态局部密度 概率密度函数 逆k最近邻 聚类结构 决策图
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LONG-TIME ASYMPTOTIC FOR THE DAMPED BOUSSINESQ EQUATION IN A CIRCLE
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作者 ZhangYi LinQun LaiShaoyong 《Journal of Partial Differential Equations》 2005年第2期97-113,共17页
The first initial-boundary value problem for the following equation utt-αΔutt-2bΔut=αΔ^3u-βΔ^2u+Δu+γΔ(u^2) in a unit circle is considered. The existence of strong solution is established in the space C^0([0... The first initial-boundary value problem for the following equation utt-αΔutt-2bΔut=αΔ^3u-βΔ^2u+Δu+γΔ(u^2) in a unit circle is considered. The existence of strong solution is established in the space C^0([0,∞),HrY^s(0,1)),s<7/2,and the solutions are constructed in the form of series in the small parameter present in the initial conditions.For 5/2<s<7/2,the uniqueness is proved.The long-time asymptotics obtained in the explicit form. 展开更多
关键词 阻尼泊松函数 初边值问题 长时渐近 强解 存在性
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Some Large Deviation Results for Generalized Compound Binomial Risk Models 被引量:1
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作者 孔繁超 赵朋 《Journal of Mathematical Research and Exposition》 CSCD 2009年第6期1047-1053,共7页
This paper is a further investigation of large deviation for partial and random sums of random variables, where {Xn,n ≥ 1} is non-negative independent identically distributed random variables with a common heavy-tail... This paper is a further investigation of large deviation for partial and random sums of random variables, where {Xn,n ≥ 1} is non-negative independent identically distributed random variables with a common heavy-tailed distribution function F on the real line R and finite mean μ∈ R. {N(n),n ≥ 0} is a binomial process with a parameter p ∈ (0,1) and independent of {Xn,n ≥ 1}; {M(n),n ≥ 0} is a Poisson process with intensity λ > 0, Sn = ΣNn i=1 Xi-cM(n). Suppose F ∈ C, we futher extend and improve some large deviation results. These results can apply to certain problems in insurance and finance. 展开更多
关键词 generalized compound binomial risk model large deviations heavy-tailed distribu-tion ruin probability.
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FINITE VOLUME ELEMENT METHOD WITH LAGRANGIAN CUBIC FUNCTIONS
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作者 Yuqiong DING Yonghai LI 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2011年第5期991-1006,共16页
This paper establishes a new finite volume element scheme for Poisson equation on trian- gular meshes. The trial function space is taken as Lagrangian cubic finite element space on triangular partition, and the test f... This paper establishes a new finite volume element scheme for Poisson equation on trian- gular meshes. The trial function space is taken as Lagrangian cubic finite element space on triangular partition, and the test function space is defined as piecewise constant space on dual partition. Under some weak condition about the triangular meshes, the authors prove that the stiffness matrix is uni- formly positive definite and convergence rate to be O(h3) in Hi-norm. Some numerical experiments confirm the theoretical considerations. 展开更多
关键词 Barycenter dual partition finite volume element method HI-estimate lagrangian cubicbasis poisson equation triangular partition.
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