检索结果-南通市图书馆

Dual-quaternion-based modeling and control for motion tracking of a tumbling target

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Engineering and Electronics 2019年第5期30卷 985-994页

作者： PENG Xuan shi xiaoping GONG Yupeng Control and Simulation Center Harbin Institute of TechnologyHarbin 150001China Research Center of Satellite Technology Harbin Institute of TechnologyHarbin 150001China

This paper investigates the problem of controlling a chasing spacecraft(chaser)to track and rendezvous with an uncontrolled target.Based on the actual situation,the torque-free motion of an axisymmetric prolate rigid body is employed to represent the short-term attitude motion of the tumbling target.By taking advantage of the dual quaternion’s compact and efficient description of the general rigid motion,the coupled and integrated model of the 6-degree-of-freedom(6-DOF)relative motion between the chaser and the tumbling target is derived in the chaser’s body fixed frame after taking full consideration of coordinate transformation.Based on the logarithm of dual quaternion,a sliding mode control(SMC)law based on the exponential reaching law and the continuous relay function is brought forward to address the problem of synchronization control of the 6-DOF relative motion.Simulation results illustrate the effectiveness of the proposed method.

关键词： tumbling target dual-quaternion coupled dynamics relative motion

CONTINUOUS AUXILIARY COVARIATE IN ADDITIVE HAZARDS REGRESSION FOR SURVIVAL DATA

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2014年第6期27卷 1247-1262页

作者： shi xiaoping LIU Yanyan WU Yuanshan School of Mathematics and System Sciences Xinjiang University School of Mathematics and Statistics Wuhan University

This paper considers the additive hazards regression analysis by utilizing continuous auxiliary covariate information to improve the efficiency of the statistical inference when the primary covariate is ascertained only for a randomly selected subsample.The authors construct a martingalebased estimating equation for the regression parameter and establish the asymptotic consistency and normality of the resultant estimators.Simulation study shows that the proposed method can greatly improve the efficiency compared with the estimator which discards the auxiliary covariate information in a variety of settings.A real example is also provided as an illustration.

关键词：回归分析风险加性随机选择统计推断回归参数工作效率协变量

Consistency of change point estimators for symmetrical stable distribution with parameters shift

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2008年第5期51卷 842-850页

作者： shi xiaoping MIAO BaiQi GE ChunLei Deptartment of Statistics and Finance University of Science and Technology of ChinaHefei 230026China College of Science Hefei University of TechnologyHefei 230009China

Assume that the characteristic indexαof stable distribution satisfies 1<α<2,and that the distribution is symmetrical about its mean.We consider the change point estimators for stable distribution withαor scale para... 详细信息

Assume that the characteristic indexαof stable distribution satisfies 1shift.For the one case that mean is a known constant,ifαorβchanges,then density function will change too.To this end,we suppose the kernel estimation for a change point.For the other case that mean is an unknown constant,we suppose to apply empirical characteristic function to estimate the change-point location.In the two cases,we consider the consistency and strong convergence rate of estimators.Furthermore,we consider the mean shift case.If mean changes,then corresponding characteristic function will change too.To this end,we also apply empirical characteristic function to estimate change point.We obtain the similar convergence rate.Finally,we consider its application on the detection of mean shift in financial market.

关键词： stable distribution change point consistency strong convergence rate

On nonparametric change point estimator based on empirical characteristic functions

在线全文

学校读者我要写书评

暂无评论

Science China Mathematics 2016年第12期59卷 2463-2484页

作者： TAN ChangChun shi xiaoping SUN XiaoYing WU YueHua School of Mathematics Hefei University of Technology Department of Mathematics and Statistics Thompson Rivers University Department of Mathematics and Statistics York University

We propose a nonparametric change point estimator in the distributions of a sequence of independent observations in terms of the test statistics given by Huˇskov′a and Meintanis(2006) that are based on weighted empirical characteristic functions. The weight function ω(t; a) under consideration includes the two weight functions from Huˇskov′a and Meintanis(2006) plus the weight function used by Matteson and James(2014),where a is a tuning parameter. Under the local alternative hypothesis, we establish the consistency, convergence rate, and asymptotic distribution of this change point estimator which is the maxima of a two-side Brownian motion with a drift. Since the performance of the change point estimator depends on a in use, we thus propose an algorithm for choosing an appropriate value of a, denoted by a_s which is also justified. Our simulation study shows that the change point estimate obtained by using a_s has a satisfactory performance. We also apply our method to a real dataset.

关键词：改变点评估者实验典型功能调节参数集中率 asymptotic 分发

工业用地市场化配置改革的制度变迁逻辑——基于“主体互动-制度共演”框架的分析

在线全文

学校读者我要写书评

暂无评论

公共行政评论 2024年第2期17卷 176-195,M0007页

作者：邹旭马贤磊石晓平南京农业大学公共管理学院南京农业大学中国资源环境与发展研究院

工业用地配置是当前要素市场化改革的重要内容。历经40余年的长期改革,市场在其中发挥的作用仍需要进一步加强,如何理解工业用地市场化配置改革的内在逻辑。通过纳入多类行为主体和关联制度,论文构建了“主体互动-制度共演”的理论框架... 详细信息

工业用地配置是当前要素市场化改革的重要内容。历经40余年的长期改革,市场在其中发挥的作用仍需要进一步加强,如何理解工业用地市场化配置改革的内在逻辑。通过纳入多类行为主体和关联制度,论文构建了“主体互动-制度共演”的理论框架,围绕改革开放以来工业用地市场化配置的改革历程和逻辑展开制度分析。研究发现,中央政府、地方政府和工业企业围绕工业用地配置制度充分互动,分别以制度供给、制度创新和制度需求的形式,在工业用地市场化配置的初步探索、发展调整和深化改革阶段主导了制度演变方向。土地产权、财政管理和政绩考核等关联制度安排也在工业用地配置制度演化过程中发挥了重要作用。研究认为,未来工业用地配置会以市场主体向上传递制度需求的互动形式深化改革,故应建立制度需求的有效反馈机制,服务企业发展和产业转型,重点优化土地利用计划管理和用途管制制度,加快培育土地二级市场和城乡统一的建设用地市场体系。

关键词：工业用地市场化配置制度变迁地方政府

维普期刊数据库博看期刊

Resource and Environmental Issues in Transitional China:A Perspective from the Interaction Among Market,Government and Society

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Population,Resources and Environment 2010年第2期8卷 13-23页

作者： Zhao Haixia Qu Futian Zhu Peixin shi xiaoping State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Nanjing Jiangsu 210008 China International Institute for Resources and Environmental Economic Studies Nanjing Agricultural University Nanjing Jiangsu 210095. China

Along with the rapid growth of economy in the postreform period after 1979,China has faced severe problems of resource overusing and environmental degradation which would threaten the sustainable development of economy and society.This article explores an effective mechanism of managing resource and environment in China.It examines some major resource and environmental issues,and constructs a framework of institution innovation to cover three sectors(government,market and society) . In addition,the article analyzes their experience and evaluation in resource management and environmental conservation during the transitional period.We argue that the combination of market regulation,government intervention and public participation is an effective way of allocating resource and protecting environment. Some suggestions are put forward to balance the relationship between them,including coordinating role of government and market,building platform for market operation and creating an atmosphere of public participation.

关键词：社会可持续发展资源管理市场调节政府干预环境问题中国公众参与环境退化

电针联合祛风化痰通窍方治疗脑梗死后吞咽障碍临床观察

在线全文

学校读者我要写书评

暂无评论

河北中医 2024年第7期46卷 1141-1145页

作者：石小平孟彦儒河北省秦皇岛市第二医院康复医学科河北秦皇岛066600

目的观察电针联合祛风化痰通窍方治疗脑梗死后吞咽障碍的临床疗效。方法将56例脑梗死后吞咽障碍患者按照随机数字表法分为2组,均予基础治疗。对照组28例予电刺激及基础康复训练,治疗组28例在对照组治疗基础上加电针联合祛风化痰通窍方... 详细信息

目的观察电针联合祛风化痰通窍方治疗脑梗死后吞咽障碍的临床疗效。方法将56例脑梗死后吞咽障碍患者按照随机数字表法分为2组,均予基础治疗。对照组28例予电刺激及基础康复训练,治疗组28例在对照组治疗基础上加电针联合祛风化痰通窍方治疗。2组均5天为1个疗程,连续治疗2个疗程。比较2组临床疗效;比较2组治疗前后洼田饮水试验评分、标准吞咽功能障碍量表(SSA)评分、吞咽困难分级评分变化;比较2组治疗前后汉密尔顿焦虑量表(HAMA)评分变化;比较2组治疗前后前白蛋白值变化;观察2组不良反应发生情况。结果治疗组总有效率96.43%(27/28),对照组总有效率75.00%(21/28),治疗组疗效优于对照组(P<0.05)。2组治疗后洼田饮水试验评分、SSA评分均较本组治疗前降低(P<0.05),吞咽困难分级评分较本组治疗前升高(P<0.05);治疗后治疗组洼田饮水试验评分、SSA评分均低于对照组(P<0.05),吞咽困难分级评分高于对照组(P<0.05)。2组治疗后HAMA评分均较本组治疗前降低(P<0.05),且治疗组降低更明显(P<0.05)。2组治疗后前白蛋白值均较本组治疗前升高(P<0.05),且治疗组升高更明显(P<0.05)。治疗组吸入性肺炎、低营养状态、焦虑加重发生率均低于对照组(P<0.05)。结论电针联合祛风化痰通窍方可明显改善脑梗死后吞咽障碍患者吞咽功能和焦虑状态,安全性高。

关键词：脑梗死吞咽障碍电针疗法中药疗法

基于残差密集卷积自编码的高噪声图像去噪方法

在线全文

学校读者我要写书评

暂无评论

计算机科学 2024年第S1期51卷 555-561页

作者：张杰卢淼鑫李嘉康徐大勇黄雯潇史小平郑州轻工业大学电气信息工程学院郑州450002 中国烟草总公司郑州烟草研究院烟草工艺重点实验室郑州450000 哈尔滨工业大学控制与仿真中心哈尔滨150080

在高噪声图像去噪中,传统卷积自编码器难以挖掘有效的深度特征信息,进而影响了图像的重建质量。为了提高高噪声图像的重建质量,提出了一种残差密集卷积自编码器网络模型。该模型首先使用卷积操作代替池化操作以提高高噪声图像的表征能力... 详细信息

在高噪声图像去噪中,传统卷积自编码器难以挖掘有效的深度特征信息,进而影响了图像的重建质量。为了提高高噪声图像的重建质量,提出了一种残差密集卷积自编码器网络模型。该模型首先使用卷积操作代替池化操作以提高高噪声图像的表征能力;同时,在编码和解码阶段设计三级密集残差网络结构,实现图像特征的有效挖掘;最后,设计一个优化损失函数以进一步提高重建图像的质量。实验结果表明,设计的去噪方法能够从高噪声图像中重建高质量的图像,同时能够保留更多的细节特征信息,有效验证了该算法在图像去噪中的有效性。该方法能够有效解决高噪声图像的去噪问题,具有重要的应用价值。

关键词：图像去噪卷积自编码器残差密集卷积高噪声图像优化损失函数

Robust Attitude Tracking Control Scheme for Flexible Spacecraft with Vibration Suspension 25th

在线全文

学校读者我要写书评

暂无评论

Robust Attitude Tracking Control Scheme for Flexible Spacecr...