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Evaluation of NLLoc positioning method and seismogenic structure analysis of Luanzhou M_(S)4.3 earthquake
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作者 Zhang Yang Wang Xiao-Shan +3 位作者 Chen Ting Lv Guo-Jun Yu Hai-lin Chen Jun-lin 《Applied Geophysics》 2025年第3期729-738,894,895,共12页
NLLoc is a nonlinear search positioning method.In this study,we use simulated arrival time data to quantitatively evaluate the NLLoc method from three aspects:arrival time picking accuracy,station distribution,and vel... NLLoc is a nonlinear search positioning method.In this study,we use simulated arrival time data to quantitatively evaluate the NLLoc method from three aspects:arrival time picking accuracy,station distribution,and velocity model.The results show that the NLLoc method exhibits high positioning accuracy and stability in terms of arrival time picking accuracy and station distribution;however,it is sensitive to the velocity model.The positioning accuracy is higher when the velocity model is smaller than the true velocity.We combined absolute and relative positioning methods.First,we use the NLLoc method for absolute positioning of seismic data and then the double difference positioning method for relative positioning to obtain a more accurate relocation result.Furthermore,we used the combined method to locate the earthquake sequence after collecting dense seismic array data on the Luanzhou M_(S)4.3 earthquake that occurred on April 16,2021,in Hebei Province.By fitting the fault plane with the relocated earthquake sequences,the results show that the strike and dip angles of the seismogenic fault of the Luanzhou M_(S)4.3 earthquake are 208.5°and 85.6°,respectively.This indicates a high-dip angle fault with North-North-East strike and North-West dip directions.Furthermore,we infer that the seismogenic fault of the Luanzhou M_(S)4.3 earthquake is the Lulong fault. 展开更多
关键词 NLLoc method Combined multiple positioning methods Luanzhou M_(s)4.3 earthquake seismogenic structure Lulong fault
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An Automatic Damage Detection Method Based on Adaptive Theory-Assisted Reinforcement Learning
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作者 Chengwen Zhang Qing Chun Yijie Lin 《Engineering》 2025年第7期188-202,共15页
Current damage detection methods based on model updating and sensitivity Jacobian matrixes show a low convergence ratio and computational efficiency for online calculations.The aim of this paper is to construct a real... Current damage detection methods based on model updating and sensitivity Jacobian matrixes show a low convergence ratio and computational efficiency for online calculations.The aim of this paper is to construct a real-time automated damage detection method by developing a theory-assisted adaptive mutiagent twin delayed deep deterministic(TA2-MATD3)policy gradient algorithm.First,the theoretical framework of reinforcement-learning-driven damage detection is established.To address the disadvantages of traditional mutiagent twin delayed deep deterministic(MATD3)method,the theory-assisted mechanism and the adaptive experience playback mechanism are introduced.Moreover,a historical residential house built in 1889 was taken as an example,using its 12-month structural health monitoring data.TA2-MATD3 was compared with existing damage detection methods in terms of the convergence ratio,online computing efficiency,and damage detection accuracy.The results show that the computational efficiency of TA2-MATD3 is approximately 117–160 times that of the traditional methods.The convergence ratio of damage detection on the training set is approximately 97%,and that on the test set is in the range of 86.2%–91.9%.In addition,the main apparent damages found in the field survey were identified by TA2-MATD3.The results indicate that the proposed method can significantly improve the online computing efficiency and damage detection accuracy.This research can provide novel perspectives for the use of reinforcement learning methods to conduct damage detection in online structural health monitoring. 展开更多
关键词 Reinforcement learning Theory-assisted Damage detection Newton’s method Model updating Architectural heritage
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A Self-Sacrifice Template Method to Produce FeS Encapsulated into N,S Co-Doped Carbon for Improved Lithium Storage Performance
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作者 Xu Liu Lan-Yun Yang +7 位作者 Li-Ting Zeng Yun Peng Chen-Xi Xu Lei Li Jia-Le Sun Yang-Yang Chen Liang Chen Zhao-Hui Hou 《Acta Metallurgica Sinica(English Letters)》 2025年第9期1637-1644,共8页
The development of high-performance transition metal sulfide(TMS)/carbon composites to replace conventional graphite anode remains a critical challenge for advancing lithium-ion batteries(LIBs).In this study,a facile ... The development of high-performance transition metal sulfide(TMS)/carbon composites to replace conventional graphite anode remains a critical challenge for advancing lithium-ion batteries(LIBs).In this study,a facile self-sacrifice template method is developed to prepare FeS encapsulated into N,S co-doped carbon(FeS/NSC)composite using melamine-cyanuric acid(MCA)supermolecule as a multifunctional template precursor.The function of MCA supermolecule for material synthesis is explored,revealing its special function as a dispersant,dopant and pore-forming agent.Furthermore,the effect of Fe source dosage on the morphology,structure and composition of the final products is explored.The resultant FeS/NSC-0.1(where 0.1 represents the mass of added Fe source)exhibits the most optimal proportion,characterized by a good dispersion status of FeS within the NSC matrix,effective N,S co-doping and ample porosity.Benefiting from these merits,the FeS/NSC-0.1 anode demonstrates significantly improved cycling stability and rate capability when compared to the counterparts.Undoubtedly,this work offers a universal method to produce advanced transition metal sulfide/carbon composite electrodes for energy storage and conversion systems. 展开更多
关键词 Lithium-ion batteries Lithium storage performance self-sacrifice template method Melamine-cyanuric acid(MCA)supermolecule Fes encapsulated into N s co-doped carbon(Fes/NsC)composite
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Clinical application and research of Shao's “three-acupoint and five-needling method” 被引量:1
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作者 张奥 严兴科 刘安国 《World Journal of Acupuncture-Moxibustion》 CSCD 2017年第1期74-80,共7页
Professor SHAO Jing-ming has obtained more significant effect during the clinical practice in treatment of wheezing diseases by adopting "three-acupoint and five-needling method" created by himself, and the effect h... Professor SHAO Jing-ming has obtained more significant effect during the clinical practice in treatment of wheezing diseases by adopting "three-acupoint and five-needling method" created by himself, and the effect has been widely recognized by doctors and patients. After decades of development, Shao's "three-acupoint and five-needling method" has become a therapy with complete theoretical system and a large number of clinical research achievements, and its application scope has been expanded. In this paper, the achievements of Shao's "three-acupoint and five-needling method" during clinical studies in the early, middle and current development stages and related problems were reviewed comprehensively. 展开更多
关键词 three-acupoint andmethod wheezing diseases clinicain the same wayfive-needling method shao's needlingobservation different diseases be treated
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基于重排S-method的多分量辐射源信号分析方法 被引量:2
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作者 荣海娜 张葛祥 金炜东 《西南交通大学学报》 EI CSCD 北大核心 2009年第2期195-200,共6页
为实现多分量辐射源信号的有效检测和识别,提出了基于重排S-method(RSM)的多分量辐射源信号分析方法.针对Wigner-Ville分布交叉项严重和计算复杂度高的问题,采用RSM分析密集、交叠的辐射源信号,给出了其算法的硬件实现和计算复杂度分析... 为实现多分量辐射源信号的有效检测和识别,提出了基于重排S-method(RSM)的多分量辐射源信号分析方法.针对Wigner-Ville分布交叉项严重和计算复杂度高的问题,采用RSM分析密集、交叠的辐射源信号,给出了其算法的硬件实现和计算复杂度分析.该方法能处理线性和非线性调频信号,算法简单,易于实现.复杂体制多分量辐射源信号分析的实验结果表明,该方法能有效分析多分量辐射源信号,时频分辨率高,不受交叉项干扰,具有比Wigner-Ville分布和S-method更强的噪声抑制能力. 展开更多
关键词 时频分析 辐射源信号 多分量 重排s-method
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基于S-method的多分量雷达辐射源信号检测 被引量:2
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作者 荣海娜 张葛祥 金炜东 《四川大学学报(工程科学版)》 EI CAS CSCD 北大核心 2009年第1期174-179,共6页
针对传统时频方法在处理多分量雷达辐射源信号时存在交叉项,不能检测各分量信号时域参数,难以适应低信噪比环境的问题,提出一种基于S-method(SM)的多分量雷达辐射源信号检测新方法。该方法首先计算信号的SM时频分布,然后在时频面的基础... 针对传统时频方法在处理多分量雷达辐射源信号时存在交叉项,不能检测各分量信号时域参数,难以适应低信噪比环境的问题,提出一种基于S-method(SM)的多分量雷达辐射源信号检测新方法。该方法首先计算信号的SM时频分布,然后在时频面的基础上检测各信号分量的瞬时频率和脉冲起止时间。实验结果表明,该方法能处理线性及非线性调频信号、时频分辨率高且不受交叉项干扰,时域检测精度大于98.60%,频域检测精度大于99.48%,信噪比降低时仍然保持强检测能力。 展开更多
关键词 辐射源信号 时频分析 多分量 信号检测 s-method
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Comparative Analysis of Improving Effects of 12 Maize Populations with Improved S_1 Selection Method
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作者 孙峰成 冯勇 +6 位作者 付增娟 苏二虎 张来厚 赵瑞霞 刘志雄 石海波 李美娜 《Agricultural Science & Technology》 CAS 2014年第10期1687-1692,1713,共7页
ln this study, 12 maize populations were improved with the improved S1 selection method, aiming to increase the improvement efficiency of maize popula-tions. The results showed that number of rows per spike, number of... ln this study, 12 maize populations were improved with the improved S1 selection method, aiming to increase the improvement efficiency of maize popula-tions. The results showed that number of rows per spike, number of grains per row and 100-grain weight were the three important component traits of maize yield. The highest genetic increment was found in Mengqun 2, fol owed by Mengqun 4, Mengqun 1 and other 7 maize populations. Negative genetic increment was shown in Mengqun 3 and 3 introduced foreign maize populations. Some changes were shown in spikes, plant traits and genetic diversity of maize populations. Based on our results, we concluded that Mengqun 2, Mengqun 4, Zhongzong 7, Mengqun C and Mengqun A could be directly used for the line breeding by selfing for their higher genetic increment of yield and better improvement effects of other agricultural traits. Compared with these 5 populations, the improvement potential of other maize populations was limited for their lower genetic increment. 展开更多
关键词 lmproved s1 selection method Maize population Genetic gain Comparative analysis
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采用Liutex涡识别法的水泵水轮机S区内流特性分析 被引量:2
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作者 肖业祥 肖微 +2 位作者 任绍成 陈柳 刘子实 《水力发电学报》 北大核心 2025年第1期135-142,共8页
为探究水泵水轮机S特性出现的原因,首先将数值预测的特性曲线与模型试验进行了对比分析,然后基于Liutex涡识别法分析了各过流部件在S特性区的流动和涡旋分布情况,探讨了S区相同转速不同流量工况下的内部流动变化规律。分析发现:相同转... 为探究水泵水轮机S特性出现的原因,首先将数值预测的特性曲线与模型试验进行了对比分析,然后基于Liutex涡识别法分析了各过流部件在S特性区的流动和涡旋分布情况,探讨了S区相同转速不同流量工况下的内部流动变化规律。分析发现:相同转速下水轮机工况蜗壳内的流动稳定性较好,几乎没有涡旋出现;导叶和转轮域内流动较为均匀,只在无叶区分布有少量涡旋,水流稳定性较好。制动工况蜗壳内流动开始变得较不稳定,涡旋集中分布在蜗壳出口环面上,容易形成涡团阻碍水流进入固定导叶;在导叶叶栅间存在明显的涡旋和回流现象,导叶和转轮的叶栅堵塞较为严重。反水泵工况在尾水管出口出现螺旋状回流,导致流入转轮的水流发生旋转失速等不稳定现象;水流一部分在活动导叶进水边沿圆周方向高速流动,存在严重的流动分离现象,涡旋分布最密集,由于无叶区内存在压力突变区,导致涡旋几乎占据整个流道。 展开更多
关键词 可逆式水泵水轮机 Liutex涡识别法 s特性区 涡旋特征
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基于概率共因失效的连续时间T-S动态故障树分析 被引量:1
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作者 古莹奎 王波 钱志远 《机械设计与制造》 北大核心 2025年第2期109-113,共5页
针对大型复杂系统存在的共因失效问题,为能够更真实反映系统的可靠性状况,提出基于概率共因失效(PCCF)的连续时间T-S动态故障树(DFT)分析方法。采用模块化方法对系统进行可靠性分析,静态故障树部分采用隐式方法,动态故障树部分采用连续... 针对大型复杂系统存在的共因失效问题,为能够更真实反映系统的可靠性状况,提出基于概率共因失效(PCCF)的连续时间T-S动态故障树(DFT)分析方法。采用模块化方法对系统进行可靠性分析,静态故障树部分采用隐式方法,动态故障树部分采用连续时间T-S动态故障树方法。利用隐式方法计算考虑PCCF的子系统故障概率,得出在不同概率共因失效组发生情况下顶事件的可靠性情况。将子系统的顶事件作为系统的底事件,构建考虑PCCF的组合连续时间T-S动态故障树,最后利用连续时间T-S动态故障树算法对整个系统进行可靠性分析。以柴油机润滑系统可靠性分析为例,通过分析考虑PCCF的连续时间T-S动态故障树并与不考虑概率共因失效的方法进行对比,验证提出方法的有效性。 展开更多
关键词 概率共因失效 模块化方法 T-s动态故障树 隐式方法 可靠性分析
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基于S-Method分布的微多普勒特征分析 被引量:3
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作者 魏迅 袁伟明 郭汝江 《电子测量技术》 2017年第1期76-80,共5页
微多普勒特征是雷达目标所具有的独特特征之一,对目标的分类、识别具有特殊的意义。研究高精度时频分析方法在分析目标微动特性中的作用,可以为后续目标识别提供很好的支撑。S-Method分布作为一种新型的时频分析方法,它基于短时傅里叶... 微多普勒特征是雷达目标所具有的独特特征之一,对目标的分类、识别具有特殊的意义。研究高精度时频分析方法在分析目标微动特性中的作用,可以为后续目标识别提供很好的支撑。S-Method分布作为一种新型的时频分析方法,它基于短时傅里叶变换来实现,减少了分析过程中的运算量,同时能较好地解决交叉项问题。首先对弹道导弹弹头的微动模型进行建模,推导得到微动模型的理论微多普勒频率,然后采用S-Method分布对回波信号进行时频分析仿真实验,获得弹头目标章动的高精度的时间-微多普勒频率图。通过比较其在分析过程中的时频分辨率、交叉项,具体阐述S-Method分布在时频分析中的优势。因此可以将S-Method分布应用于雷达目标微多普勒分析中,分析实时变化的微多普勒频率特征。 展开更多
关键词 微动 微多普勒 s-method分布 时频分析
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Q-factor estimation in CMP gather and the continuous spectral ratio slope method 被引量:5
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作者 Wu Zong-Wei Wu Yi-Jia +1 位作者 Guo Si Xu Ming-Hua 《Applied Geophysics》 SCIE CSCD 2018年第3期481-490,共10页
The attenuation factor or quality factor(Q-factor or Q) has been used to measure the energy attenuation of seismic waves propagating in underground media. Many methods are used to estimate the Q-factor. We propose a m... The attenuation factor or quality factor(Q-factor or Q) has been used to measure the energy attenuation of seismic waves propagating in underground media. Many methods are used to estimate the Q-factor. We propose a method to calculate the Q-factor based on the prestack Q-factor inversion and the generalized S-transform. The proposed method specifies a standard primary wavelet and calculates the cumulative Q-factors; then, it finds the interlaminar Q-factors using the relation between Q and offset(QVO) and the Dix formula. The proposed method is alternative to methods that calculate interlaminar Q-factors after horizon picking. Because the frequency spectrum of each horizon can be extracted continuously on a 2D time–frequency spectrum, the method is called the continuous spectral ratio slope(CSRS) method. Compared with the other Q-inversion methods, the method offers nearly effortless computations and stability, and has mathematical and physical significance. We use numerical modeling to verify the feasibility of the method and apply it to real data from an oilfield in Ahdeb, Iraq. The results suggest that the resolution and spatial stability of the Q-profile are optimal and contain abundant interlaminar information that is extremely helpful in making lithology and fluid predictions. 展开更多
关键词 Quality FACTOR PREsTACK Q EsTIMATION generalized s transform spectral ratio sLOPE method Q versus offset
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2021年11月17日江苏大丰海域M_(S)5.0地震震源机制与发震构造
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作者 康清清 于悦颖 +9 位作者 顾勤平 李玲利 刘芳 王维 杨云 王俊菲 许田 周昱辰 孙小航 孙宗强 《地球物理学报》 北大核心 2025年第5期1884-1895,共12页
基于江苏、山东和上海等区域地震台网宽频带波形资料,采用gCAP波形反演法获取了2021年11月17日江苏大丰海域M_(S)5.0地震的震源机制解、震源矩心深度和矩震级.节面Ⅰ走向96°、倾角71°、滑动角17°;节面Ⅱ走向0°、倾... 基于江苏、山东和上海等区域地震台网宽频带波形资料,采用gCAP波形反演法获取了2021年11月17日江苏大丰海域M_(S)5.0地震的震源机制解、震源矩心深度和矩震级.节面Ⅰ走向96°、倾角71°、滑动角17°;节面Ⅱ走向0°、倾角74°、滑动角160°,说明震源机制以走滑为主.P轴仰角2°,方位48°,反映震源区主压应力呈NEE-SWW向水平推挤特征,与华东现代构造应力场方向基本一致,揭示其受区域应力场控制.本次地震矩震级为MW5.1,与面波震级M_(S)5.0、近震震级ML5.2较为一致.震源矩心深度为14.7 km,与重定位后的震源初始破裂深度16.5 km较接近,推测该地震发生在南黄海盆地地壳中部,震源由深至浅破裂,震源破裂尺度约3.5 km.重定位后余震展布呈现共轭型带状分布,优势分布方向为NWW向和NE向,NE向展布方向与震源机制解两节面走向均不匹配,震中附近亦没有已探明并公布的NE向断裂;而NWW向展布与节面Ⅰ走向相匹配,与附近的南部坳陷西侧断裂走向基本一致,结合区域重、磁场异常分布情况,初步判定节面Ⅰ为同震破裂面.我们推测本次地震为南部坳陷西侧断裂在NEESWW向水平主压应力作用下挤压错动所致,呈NE向线性展布的零星余震穿越苏北—滨海断裂并向SW延伸至大丰海岸线附近,不排除其下方存在NE-SW向展布的隐伏断层,主震发震断层的错动诱发了该断层活动. 展开更多
关键词 大丰海域M_(s)5.0地震 gCAP方法 震源机制解 地震重定位 发震构造
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Study on Characteristics of 3-D Translating-Pulsating Source Green Function of Deep-Water Havelock Form and Its Fast Integration Method 被引量:20
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作者 许勇 董文才 《China Ocean Engineering》 SCIE EI 2011年第3期365-380,共16页
The singularities, oscillatory performances and the contributing factors to the 3-'D translating-pulsating source Green function of deep-water Havelock form which consists of a local disturbance part and a far-field ... The singularities, oscillatory performances and the contributing factors to the 3-'D translating-pulsating source Green function of deep-water Havelock form which consists of a local disturbance part and a far-field wave-like part, are analyzed systematically. Relative numerical integral methods about the two parts are presented in this paper. An improved method based on LOBATTO rule is used to eliminate singularities caused respectively by infinite discontinuity and jump discontinuous node from the local disturbance part function, which makes the improvement of calculation efficiency and accuracy possible. And variable substitution is applied to remove the singularity existing at the end of the integral interval of the far-field wave-like part function. Two auxiliary techniques such as valid interval calculation and local refinement of integral steps technique in narrow zones near false singularities are applied so as to avoid unnecessary integration of invalid interval and improve integral accordance. Numerical test results have proved the efficiency and accuracy in these integral methods that thus can be applied to calculate hydrodynamic performance of floating structures moving in waves. 展开更多
关键词 translating-pulsating source Green's function singularity highly oscillatory function integration method
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Exp-Function Method and Fractional Complex Transform for Space-Time Fractional KP-BBM Equation 被引量:10
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作者 Ozkan Guner 《Communications in Theoretical Physics》 SCIE CAS CSCD 2017年第8期149-154,共6页
In the present article, He's fractional derivative, the ansatz method, the ( C / G)-expansion method, and the exp-function method are used to construct the exact solutions of nonlinear space-time fractional Kadomts... In the present article, He's fractional derivative, the ansatz method, the ( C / G)-expansion method, and the exp-function method are used to construct the exact solutions of nonlinear space-time fractional Kadomtsev-Petviashvili- Benjamin-Bona Mahony (KP-BBM). As a result, different types of exact solutions are obtained. Also we have examined the relation between the solutions obtained from the different methods. These methods are an efficient mathematical tool for solving fractional differential equations (FDEs) and it can be applied to other nonlinear FDEs. 展开更多
关键词 ansatz method exp-function method He's fractional derivative (G'/G)-expansion method spacetime fractional KP-BBM equation
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Fractal Method for Statistical Analysis Geological Data 被引量:2
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作者 Meng Xianguo Zhao PengdaChina University of Geosciences , Wuhan 430074 《Journal of Earth Science》 SCIE CAS CSCD 1991年第1期114-119,共6页
This paper establishes the phase space in the light of spacial series data , discusses the fractal structure of geological data in terms of correlated functions and studies the chaos of these data . In addition , it i... This paper establishes the phase space in the light of spacial series data , discusses the fractal structure of geological data in terms of correlated functions and studies the chaos of these data . In addition , it introduces the R/S analysis for time series analysis into spacial series to calculate the structural fractal dimensions of ranges and standard deviation for spacial series data -and to establish the fractal dimension matrix and the procedures in plotting the fractal dimension anomaly diagram with vector distances of fractal dimension . At last , it has examples of its application . 展开更多
关键词 geological data fractal method fractal dimension space series R/s analysis .
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Measuring Recreational Value of World Heritage Sites Based on Contingent Valuation Method:A Case Study of Jiuzhaigou 被引量:9
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作者 DONG Xuewang ZHANG Jie +2 位作者 ZHI Ruizhi ZHONG Shi'en LI Min 《Chinese Geographical Science》 SCIE CSCD 2011年第1期119-128,共10页
World heritage possesses various kinds of use value and non-use value. Measuring the recreational value of world heritage sites is a key issue in the heritage tourism. This paper employs Contingent Valuation Method (C... World heritage possesses various kinds of use value and non-use value. Measuring the recreational value of world heritage sites is a key issue in the heritage tourism. This paper employs Contingent Valuation Method (CVM), which is an evaluation instrument on the basis of tourists′ attitude and preference, to measure the recreational value of Jiuzhaigou, one of the World Natural Heritage sites in China, and analyzes the biases in the survey. The results show that: 1) In 2009, Jiuzhaigou′s recreational value was 3.46×108 yuan (RMB), and the per capita Willingness to Pay (WTP) was 137.31 yuan by CVM. Compared with the results of other methods, this result is significantly low. 2) Among the factors that influence Jiuzhaigou tourists′ WTP, psychological perception factors have the greatest effect while demographic and socio-economic characteristics have a small effect on WTP. 3) The virtuality in CVM creates biases both from CVM itself and in the procedures that CVM was implemented. The former includes hypothetical bias, information bias, protest response bias, and strategic bias; and the latter includes the questionnaire design, population and sample definition, sampling and data processing. The paper analyses those biases and illustrates their potential in-fluences on the accuracy of CVM measurement. 4) Although there are various defects in CVM measurement, it is still an effective valuation method. 展开更多
关键词 Contingent Valuation method (CVM) Willingness to Pay (WTP) tourist's attitude tourist's preference world heritage recreational value BIAs Jiuzhalgou
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A Family of Fifth-order Iterative Methods for Solving Nonlinear Equations 被引量:4
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作者 Liu Tian-Bao Cai Hua Li Yong 《Communications in Mathematical Research》 CSCD 2013年第3期255-260,共6页
In this paper, we present and analyze a family of fifth-order iterative methods free from second derivative for solving nonlinear equations. It is established that the family of iterative methods has convergence order... In this paper, we present and analyze a family of fifth-order iterative methods free from second derivative for solving nonlinear equations. It is established that the family of iterative methods has convergence order five. Numerical examples show that the new methods are comparable with the well known existing methods and give better results in many aspects. 展开更多
关键词 Newton's method iterative method nonlinear equation order of convergence
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A DIAGONAL SPLIT-CELL MODEL FOR THE OVERLAPPING YEE FDTD METHOD 被引量:3
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作者 Jinjie Liu Moysey Brio Jerome V. Moloney 《Acta Mathematica Scientia》 SCIE CSCD 2009年第6期1670-1676,共7页
In this paper, we present a nonorthogonal overlapping Yee method for solv- ing Maxwell's equations using the diagonal split-cell model. When material interface is presented, the diagonal split-cell model does not req... In this paper, we present a nonorthogonal overlapping Yee method for solv- ing Maxwell's equations using the diagonal split-cell model. When material interface is presented, the diagonal split-cell model does not require permittivity averaging so that better accuracy can be achieved. Our numerical results on optical force computation show that the standard FDTD method converges linearly, while the proposed method achieves quadratic convergence and better accuracy. 展开更多
关键词 FDTD method Overlapping Yee method Maxwell's equations Optical force
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Function Combined Method for Design Innovation of Children's Bike 被引量:4
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作者 WU Xiaoli QIU Tingting CHEN Huijuan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第2期242-247,共6页
As children mature, bike products for children in the market develop at the same time, and the conditions are frequently updated. Certain problems occur when using a bike, such as cycle overlapping, repeating function... As children mature, bike products for children in the market develop at the same time, and the conditions are frequently updated. Certain problems occur when using a bike, such as cycle overlapping, repeating function, and short life cycle, which go against the principles of energy conservation and the environmental protection intensive design concept. In this paper, a rational multi-function method of design through functional superposition, transformation, and technical implementation is proposed. An organic combination of frog-style scooter and children’s tricycle is developed using the multi-function method. From the ergonomic perspective, the paper elaborates on the body size of children aged 5 to 12 and effectively extracts data for a multi-function children’s bike, which can be used for gliding and riding. By inverting the body, parts can be interchanged between the handles and the pedals of the bike. Finally, the paper provides a detailed analysis of the components and structural design, body material, and processing technology of the bike. The study of Industrial Product Innovation Design provides an effective design method to solve the bicycle problems, extends the function problems, improves the product market situation, and enhances the energy saving feature while implementing intensive product development effectively at the same time. 展开更多
关键词 children’s bike function combined method ERGONOMICs function transformed
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基于自适应阈值滤波和S-Method的穿墙人体动作识别 被引量:2
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作者 王凡 刘丽 +2 位作者 徐航 李静霞 王冰洁 《电子器件》 CAS 北大核心 2021年第5期1265-1273,共9页
穿墙人体动作识别在武装反恐、城市巷战、灾害救援、病人监护等领域具有重要的应用价值。传统的基于短时傅里叶变换(Short-Time Fourier Transform,STFT)的时频分析方法时频分辨率低,不利于后期的分类识别。本文提出了一种基于自适应阈... 穿墙人体动作识别在武装反恐、城市巷战、灾害救援、病人监护等领域具有重要的应用价值。传统的基于短时傅里叶变换(Short-Time Fourier Transform,STFT)的时频分析方法时频分辨率低,不利于后期的分类识别。本文提出了一种基于自适应阈值滤波和S-Method的时频特征增强方法,用于墙后人体动作识别。该方法首先利用自适应阈值滤波消除时频图中的噪声,然后采用S-Method方法聚焦能量,提高时频特征,最后利用K最近邻(KNN)分类器对人体动作进行识别。利用频率步进穿墙雷达获取的实验数据进行方法验证,结果表明:相比于传统的STFT方法,本文所提出的方法对走、跑、坐、跳、招手以及原地踏步等6种典型动作的平均识别准确率更高,可达96.11%。 展开更多
关键词 人体动作识别 穿墙雷达 时频分析 自适应阈值滤波 s-method K最近邻值
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