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Differentiation degree combination weighting method for investment decision-making risk assessment in power grid construction projects 被引量:5
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作者 Yuan Chang Chenmiao liu +4 位作者 Minghua liu Wenxia liu zongqi liu Heng Zhang Yan Zheng 《Global Energy Interconnection》 2019年第5期466-478,共13页
Power grid construction projects are distinguished by their wide variety,high investment,long payback period,and close relation to national development and human welfare.To improve the investment accuracy in such proj... Power grid construction projects are distinguished by their wide variety,high investment,long payback period,and close relation to national development and human welfare.To improve the investment accuracy in such projects and effectively prevent investment risks,this paper proposes an investment optimization decision-making method for multiple power grid construction projects under a certain investment scale.Firstly,an in-depth analysis of the characteristics and development requirements of China’s power grid projects was performed.Thereafter,the time sequence and holographic method was adopted to conduct multi-dimensional,multi-perspective risk assessment of different parts of power grid projects,and a holographic risk assessment index system was developed.Moreover,an investment decision model considering the comprehensive risk based on combination weighting was developed according to the output and input of power grid construction projects.A new combination weighting optimization method that takes into account the investment willingness of enterprises was designed to improve the current weighting evaluation methods.Finally,the validity and applicability of the proposed evaluation method were verified by case examples. 展开更多
关键词 Power GRID PROJECTS Risk assessment Time SEQUENCE Index system Combination weighting
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Strain localization of Mohr-Coulomb soils with non-associated plasticity based on micropolar continuum theory 被引量:2
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作者 Jianbin Tang Xi Chen +1 位作者 liusheng Cui zongqi liu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2023年第12期3316-3327,共12页
To address the problems of strain localization, the exact Mohr-Coulomb (MC) model is used based on second-order cone programming (mpcFEM-SOCP) in the framework of micropolar continuum finite element method. Using the ... To address the problems of strain localization, the exact Mohr-Coulomb (MC) model is used based on second-order cone programming (mpcFEM-SOCP) in the framework of micropolar continuum finite element method. Using the uniaxial compression test, we focused on the earth pressure problem of rigid wall segment involving non-associated plasticity. The numerical results reveal that when mpcFEM-SOCP is applied, the problems of mesh dependency can be effectively addressed. For geotechnical strain localization analysis involving non-associated MC plasticity, mpcFEM-SOCP in conjunction with the pseudo-time discrete scheme can improve the numerical stability and avoid the unreasonable softening issue in the pressure-displacement curves, which may be encountered in the conventional FEM. It also shows that the pressure-displacement responses calculated by mpcFEM-SOCP with the pseudo-time discrete scheme are higher than those calculated by mpcFEM-SOCP with the Davis scheme. The inclination angle of shear band predicted by mpcFEM-SOCP with the pseudo-time discrete scheme agrees well with the theoretical solution of non-associated MC plasticity. 展开更多
关键词 Strain localization Micropolar continuum Mohr-Coulomb(MC)model Non-associated plasticity Second-order cone programming
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2019-2020年某县儿童青少年视力不良状况分析 被引量:2
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作者 邓常青 钟子馨 +1 位作者 刘宗奇 钟贵良 《湖南师范大学学报(医学版)》 2022年第6期124-128,共5页
目的:对2019-2020年某县儿童青少年视力不良的状况进行分析,以该县所在市的视力不良数据进行建模,预测儿童青少年视力不良发展趋势,进而为针对性地进行视力不良的防控干预和相关政策法规的制定提供数据支撑和理论依据.方法:收集某县2019... 目的:对2019-2020年某县儿童青少年视力不良的状况进行分析,以该县所在市的视力不良数据进行建模,预测儿童青少年视力不良发展趋势,进而为针对性地进行视力不良的防控干预和相关政策法规的制定提供数据支撑和理论依据.方法:收集某县2019-2020年儿童青少年视力不良的数据,用描述流行病学方法,采用excel软件,计算各年级、性别视力不良检出率、程度分布等指标,通过统计图和统计表对性别、年级、程度的分布特点进行直观的描述分析.以基本数据为支撑,获得该县所在市区的2019年男生、2019年女生、2020年男生、2020年女生的视力不良检出率,并且以这四类视力不良检出率进行曲线拟合,拟合增长模型选择R^(2)即决定系数最高的模型作为此次函数模型,视力不良检出率增龄性增长曲线模型由对视力不良检出率增长模型求一阶导数获得.结果:某县2019年儿童青少年视力不良检出率的结果是42.4%,2020年视力不良检出率的结果是42.41%,差异没有统计学意义.不同性别的视力不良检出率之中,差异存在统计学意义.2020年该县所在市青少年视力不良检出率男生61.9%,女生69.87%,男女与2019年相比均有明显上升.性别是儿童青少年视力不良的影响因素,这是由logistic回归分析的结果发现得出,所以视力不良检出率增龄性增长曲线模型分为2019年男生、2019年女生、2020年男生、2020年女生四类数据来建立.结论:随着年级的增加,视力不良检出率逐渐呈现上升趋势,中、重度视力不良随各学段年级的增加,检出人数不断增多.视力不良女生的检出率比男生高.儿童青少年视力不良正向低龄化发展,我们应该在小学时期或更早时期联合家长以及学习严格采取措施预防视力不良. 展开更多
关键词 视力不良 儿童 青少年 近视
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