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Bayes条件下非线性模型的参数置信域的曲率表示
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作者 吴一凡 《南京师大学报(自然科学版)》 CAS CSCD 北大核心 2011年第2期27-33,共7页
给出了Bayes条件下非线性模型的参数估计,建立了该模型的几何结构,推广了Bates&Wates关于非线性回归模型的几何框架,在此基础上,用几何方法探讨了关于参数与子集参数置信域的曲率表示.
关键词 Bayes条件下非线性模型 参数估计 几何结构 置信域 曲率
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有限总体中的条件最优线性无偏预测 被引量:1
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作者 梁小林 《长沙交通学院学报》 2002年第4期1-3,共3页
研究了有限总体中的预测问题 ,给出了条件线性无偏预测的定义 ,并得到了唯一条件最优线性无偏预测函数。
关键词 条件最优线性无偏预测 有限总体 条件预测 最优预测 条件线性模型
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船舶航行非线性规避碍航物航线方法研究
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作者 李成海 胡甚平 +1 位作者 崔建辉 王建涛 《江苏航运职业技术学院学报》 2023年第4期30-34,共5页
传统的航行船舶规避碍航物航线预估方法针对范围小,对于碍航物小目标预估准确率低或遗漏小目标,不利于航行船舶的安全。针对上述问题,提出了基于非线性条件模型的航行船舶规避碍航物航行航线预估方法。根据航行船舶规避碍航物预估具有... 传统的航行船舶规避碍航物航线预估方法针对范围小,对于碍航物小目标预估准确率低或遗漏小目标,不利于航行船舶的安全。针对上述问题,提出了基于非线性条件模型的航行船舶规避碍航物航行航线预估方法。根据航行船舶规避碍航物预估具有非线性的特性,首先构建航行船舶规避碍航物航行航线非线性条件下初始模型,根据条件模型变量之间的关系,定义规避碍航物条件模型;然后对规避碍航物非线性条件模型进行规避碍航物航行航线程序计算;最后通过实验验证的数据分析,进一步证明了该研究方法能够提高对范围小、碍航物小目标的预估准确率,防止遗漏小目标,对保障航行船舶安全具有较强的现实意义。 展开更多
关键词 航行船舶 线性条件模型 规避碍航物 航行航线预估
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边缘化迭代容积卡尔曼滤波的单站无源定位算法 被引量:1
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作者 张智 姜秋喜 潘继飞 《信号处理》 CSCD 北大核心 2014年第8期924-929,共6页
针对单站无源定位可观测性弱、观测噪声大而导致的定位精度低、收敛速度慢等问题,提出了一种边缘化迭代容积卡尔曼滤波算法。该算法采用基于似然增加的迭代策略,不需要设置判决门限,且保证了算法的全局收敛性。同时,其充分考虑状态向量... 针对单站无源定位可观测性弱、观测噪声大而导致的定位精度低、收敛速度慢等问题,提出了一种边缘化迭代容积卡尔曼滤波算法。该算法采用基于似然增加的迭代策略,不需要设置判决门限,且保证了算法的全局收敛性。同时,其充分考虑状态向量与观测噪声之间的互协方差,将状态向量扩维,构造条件线性模型并进行边缘化滤波,不仅提高了算法的定位精度以及收敛速度,还减少了扩维后所需的采样点,提高了算法的运算效率。仿真结果表明,新算法改善了单站无源定位的定位精度以及收敛速度。 展开更多
关键词 单站无源定位 边缘化 迭代容积卡尔曼滤波 似然增加 扩维 条件线性模型
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Effects of temperature fluctuations on cuttlebone formation of cuttlefish Sepia esculenta 被引量:2
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作者 雷舒涵 张秀梅 +1 位作者 刘松林 陈四清 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第4期547-553,共7页
The morphological characteristics and the cuttlebone formation of Sepia esculenta exposed to different water temperature fluctuations were investigated under laboratory conditions. Temperature fluctuation cycles (15 ... The morphological characteristics and the cuttlebone formation of Sepia esculenta exposed to different water temperature fluctuations were investigated under laboratory conditions. Temperature fluctuation cycles (15 cycles, 60 d in total) consisted of the following three regimes of 4 d duration: keeping water temperature in 26℃ for 3 d (Group A), 2 d (Group B), 0 d (Group C, control); then keeping water temperature in 16℃ for the next 1, 2, 4 d. No significant difference in the survival rate was observed between the control and temperature fluctuation groups (P〉0.05). Lamellar depositions in a temperature fluctuation cycle were 2.45±0.02 for Group A, 2.00±0.02 for Group B, and 1.78±0.02 for Group C (P〈0.05). The relationship between age and number of lamellas in the cuttlebone of S. esculenta under each water temperature fluctuation could be described as the linear model and the number of lamellas in the cuttlebone did not correspond to actual age. Group A had the highest cuttlebone growth index (CGI), the lowest locular index (LI), and inter-streak distances comparing with those of control group. However, the number of lamellas and LI or CGI showed a quadratic relationship for each temperature fluctuation group. In addition, temperature fluctuations caused the breakage of cuttlebone dark rings, which was considered a thermal mark. The position of the breakage in the dark rings was random. This thermal mark can be used as supplementary information for marking and releasing techniques. 展开更多
关键词 Sepia esculenta cuttlebone formation temperature fluctuations cuttlebone growth index locular index inter-streak distances
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Interannual and Seasonal Variability of Winter-Spring Cohort of Neon Flying Squid Abundance in the Northwest Pacific Ocean During 1995–2011 被引量:5
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作者 YU Wei CHEN Xinjun YI Qian 《Journal of Ocean University of China》 SCIE CAS 2016年第3期480-488,共9页
The neon flying squid, Ommastrephes bartramii, is a species of economically important cephalopod in the Northwest Pacific Ocean. Its short lifespan increases the susceptibility of the distribution and abundance to the... The neon flying squid, Ommastrephes bartramii, is a species of economically important cephalopod in the Northwest Pacific Ocean. Its short lifespan increases the susceptibility of the distribution and abundance to the direct impact of the environmental conditions. Based on the generalized linear model(GLM) and generalized additive model(GAM), the commercial fishery data from the Chinese squid-jigging fleets during 1995 to 2011 were used to examine the interannual and seasonal variability in the abundance of O. bartramii, and to evaluate the influences of variables on the abundance(catch per unit effort, CPUE). The results from GLM suggested that year, month, latitude, sea surface temperature(SST), mixed layer depth(MLD), and the interaction term(SST×MLD) were significant factors. The optimal model based on GAM included all the six significant variables and could explain 42.43% of the variance in nominal CPUE. The importance of the six variables was ranked by decreasing magnitude: year, month, latitude, SST, MLD and SST×MLD. The squid was mainly distributed in the waters between 40?N and 44?N in the Northwest Pacific Ocean. The optimal ranges of SST and MLD were from 14 to 20℃ and from 10 to 30 m, respectively. The squid abundance greatly fluctuated from 1995 to 2011. The CPUE was low during 1995–2002 and high during 2003–2008. Furthermore, the squid abundance was typically high in August. The interannual and seasonal variabilities in the squid abundance were associated with the variations of marine environmental conditions and the life history characteristics of squid. 展开更多
关键词 Ommastrephes bartramii abundance variability Chinese squid-jigging fishery generalized linear model generalizedadditive model
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Cubature卡尔曼滤波-卡尔曼滤波算法 被引量:13
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作者 孙枫 唐李军 《控制与决策》 EI CSCD 北大核心 2012年第10期1561-1565,共5页
针对条件线性高斯状态空间模型,提出cubature卡尔曼滤波-卡尔曼滤波算法(CKF-KF),分别应用CKF和KF估计模型中的非线性和线性状态.该算法对非线性与线性状态均进行cubature采样,并将两种样本通过线性方程和量测方程进行传播,以获得非线... 针对条件线性高斯状态空间模型,提出cubature卡尔曼滤波-卡尔曼滤波算法(CKF-KF),分别应用CKF和KF估计模型中的非线性和线性状态.该算法对非线性与线性状态均进行cubature采样,并将两种样本通过线性方程和量测方程进行传播,以获得非线性状态估计.机动目标跟踪仿真结果表明,CKF-KF的估计精度比Rao-Blackwellized粒子滤波器(RBPF)略低,但算法运行时间不到其1%;与无迹卡尔曼滤波器(UKF-KF)相比,估计精度相当,但算法运行时间降低了22%,有效地提高了实时性. 展开更多
关键词 条件线性高斯模型 cubature卡尔曼滤波-卡尔曼滤波 无迹卡尔曼滤波器 实时性
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Approximate Conditional Likelihood for Generalized Linear Models with General Missing Data Mechanism 被引量:7
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作者 ZHAO Jiwei SHAO Jun 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2017年第1期139-153,共15页
The generalized linear model is an indispensable tool for analyzing non-Gaussian response data, with both canonical and non-canonical link functions comprehensively used. When missing values are present, many existing... The generalized linear model is an indispensable tool for analyzing non-Gaussian response data, with both canonical and non-canonical link functions comprehensively used. When missing values are present, many existing methods in the literature heavily depend on an unverifiable assumption of the missing data mechanism, and they fail when the assumption is violated. This paper proposes a missing data mechanism that is as generally applicable as possible, which includes both ignorable and nonignorable missing data cases, as well as both scenarios of missing values in response and covariate.Under this general missing data mechanism, the authors adopt an approximate conditional likelihood method to estimate unknown parameters. The authors rigorously establish the regularity conditions under which the unknown parameters are identifiable under the approximate conditional likelihood approach. For parameters that are identifiable, the authors prove the asymptotic normality of the estimators obtained by maximizing the approximate conditional likelihood. Some simulation studies are conducted to evaluate finite sample performance of the proposed estimators as well as estimators from some existing methods. Finally, the authors present a biomarker analysis in prostate cancer study to illustrate the proposed method. 展开更多
关键词 Asymptotic normality generalized linear model IDENTIFIABILITY missing data mechanism non-canonical link function nonignorable missingness.
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Numerical Study of Greenhouse Nocturnal Heat Losses 被引量:2
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作者 F.Berroug E.K.Lakhal +2 位作者 M.El Omari M.Faraji H.El Qarnia 《Journal of Thermal Science》 SCIE EI CAS CSCD 2011年第4期377-384,共8页
In this study we quantify and analyze different components of nocturnal losses from a heated greenhouse with the presence of vegetation for typical winter weather conditions in Marrakesh-Morocco,using a non linear mod... In this study we quantify and analyze different components of nocturnal losses from a heated greenhouse with the presence of vegetation for typical winter weather conditions in Marrakesh-Morocco,using a non linear model,based on the greenhouse heat and mass balance.It was found that 12% of the total input heat was dissipate as a sensible and latent leakage losses,66% was lost by convective exchange through air-inner cover.This gain of energy at the inner-cover is dissipated at the outer-cover by radiation(66%)and convection(34%).This results point toward some practical measures to reduce heat losses:increasing air tightness,using covering materials with low-emissivity in the long wave band or putting up an external thermal curtain should provide significant energy savings. 展开更多
关键词 GREENHOUSE energy balance heat losses numerical analysis.
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NEW RESULTS ABOUT THE RELATIONSHIP BETWEEN OPTIMALLY WEIGHTED LEAST SQUARES ESTIMATE AND LINEAR MINIMUM VARIANCE ESTIMATE
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作者 Juan ZHAO Yunmin ZHU 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2009年第1期137-149,共13页
The optimally weighted least squares estimate and the linear minimum variance estimateare two of the most popular estimation methods for a linear model.In this paper,the authors makea comprehensive discussion about th... The optimally weighted least squares estimate and the linear minimum variance estimateare two of the most popular estimation methods for a linear model.In this paper,the authors makea comprehensive discussion about the relationship between the two estimates.Firstly,the authorsconsider the classical linear model in which the coefficient matrix of the linear model is deterministic,and the necessary and sufficient condition for equivalence of the two estimates is derived.Moreover,under certain conditions on variance matrix invertibility,the two estimates can be identical providedthat they use the same a priori information of the parameter being estimated.Secondly,the authorsconsider the linear model with random coefficient matrix which is called the extended linear model;under certain conditions on variance matrix invertibility,it is proved that the former outperforms thelatter when using the same a priori information of the parameter. 展开更多
关键词 Conditional expectation linear minimum variance estimation necessary and sufficient condition optimally weighted least squares estimation.
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