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Correction of Corporation Value Assessment Model Based on Corporate Social Responsibility
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作者 贠晓兰 《Agricultural Science & Technology》 CAS 2017年第4期736-739,共4页
The performance of corporate social responsibility is conducive to the con- tinuous improvement of their profitability, and promotes the upgrading of corporation value. However, it is difficult to confirm, calculate a... The performance of corporate social responsibility is conducive to the con- tinuous improvement of their profitability, and promotes the upgrading of corporation value. However, it is difficult to confirm, calculate and check the costs and benefits brought by the implementation of corporate social responsibility under the current ac- counting theory system, so it is difficult to estimate whether the fulfillment of corpo- rate social responsibility has any effects on the corporation value assessment. Therefore, based on corporate social responsibility, the correction mode of corpora- tion value assessment is put forward. 展开更多
关键词 Corporation value Social responsibility Assessment model correction model
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Quantum Corrections on Relativistic Mean Field Theory for Nuclear Matter 被引量:1
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作者 张启仁 高春媛 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第5期765-770,共6页
We propose a quantization procedure for the nucleon-scMar meson system, in which an arbitrary mean scalar meson field Ф is introduced. The equivalence of this procedure with the usual one is proven for any given valu... We propose a quantization procedure for the nucleon-scMar meson system, in which an arbitrary mean scalar meson field Ф is introduced. The equivalence of this procedure with the usual one is proven for any given value of qS. By use of this procedure, the scalar meson field in the Walecka's MFA and in Chin's RHA are quantized around the mean field, Its corrections on these theories are considered by perturbation up to the second order. The arbitrariness of Ф makes us free to fix it at any stage in the calculation. When we fix it in the way of Walecka's MFA, the quantum corrections are big, and the result does not converge. When we fix it in the way of Chin's RHA, the quantum correction is negligibly small, and the convergence is excellent. It shows that RHA covers the leading part of quantum field theory for nuclear systems and is an excellent zeroth order approximation for further quantum corrections, while the Walecka's MFA does not. We suggest to fix the parameter Ф at the end of the whole calculation by minimizing the total energy per-nucleon for the nuclear matter or the total energy for the finite nucleus, to make the quantized relativistic mean field theory (QRMFT) a variational method. 展开更多
关键词 relativistic mean field theory quantum corrections quantization around a classical value
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Correction of failure in antenna array using matrix pencil technique
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作者 S U Khan M K A Rahim 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第6期491-498,共8页
In this paper a non-iterative technique is developed for the correction of faulty antenna array based on matrix pencil technique(MPT). The failure of a sensor in antenna array can damage the radiation power pattern ... In this paper a non-iterative technique is developed for the correction of faulty antenna array based on matrix pencil technique(MPT). The failure of a sensor in antenna array can damage the radiation power pattern in terms of sidelobes level and nulls. In the developed technique, the radiation pattern of the array is sampled to form discrete power pattern information set. Then this information set can be arranged in the form of Hankel matrix(HM) and execute the singular value decomposition(SVD). By removing nonprincipal values, we obtain an optimum lower rank estimation of HM. This lower rank matrix corresponds to the corrected pattern. Then the proposed technique is employed to recover the weight excitation and position allocations from the estimated matrix. Numerical simulations confirm the efficiency of the proposed technique, which is compared with the available techniques in terms of sidelobes level and nulls. 展开更多
关键词 array correction low rank estimation matrix pencil technique singular value decomposition
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SINGULAR PERTURBATIONS FOR A CLASS OF BOUNDARY VALUE PROBLEMS OF HIGHER ORDER NONLINEAR DIFFERENTIAL EQUATIONS
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作者 史玉明 刘光旭 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1996年第12期1193-1201,共9页
In this paper, it has been studied that the singular perturbations for the higherorder nonlinear boundary value problem of the formε2y(n)=f(t, ε, y. '', y(n-2))pj(ε)y(1)(0, ε)-qj(ε)y(j+1)(0. ε)=Aj(ε) (0... In this paper, it has been studied that the singular perturbations for the higherorder nonlinear boundary value problem of the formε2y(n)=f(t, ε, y. '', y(n-2))pj(ε)y(1)(0, ε)-qj(ε)y(j+1)(0. ε)=Aj(ε) (0≤j≤n-3)a1(ε)u(n-2)(0.ε)-a2(ε)y(n-1)(0, ε)=B(ε)b1(ε)y(n-2)(1, ε)+b2(ε)y(n-1),(1. ε)=C(ε)by the method of higher order differential inequalities and boundary layer corrections.Under some mild conditions, the existence of the perturbed solution is proved and itsuniformly efficient asymptotic expansions up to its n-th order derivative function aregiven out. Hence, the existing results are extended and improved. 展开更多
关键词 nonlinear boundary value problem singular perturbation uniformly efficient asymptotic expansion higher orderdifferential inequalities boundary layer correction
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FVC and FEV Reference Values for Beninese Individuals Aged 17 - 20 Years
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作者 Folly Messan Mohamed M. Lawani Daouda Mama 《Open Journal of Respiratory Diseases》 2019年第2期48-59,共12页
Background: 1) To determine forced vital capacity (FVC) and forced expiratory volume in one second (FEV) for Beninese individuals of both sexes aged 17 - 20 years;2) Compare the observed values to those calculated bas... Background: 1) To determine forced vital capacity (FVC) and forced expiratory volume in one second (FEV) for Beninese individuals of both sexes aged 17 - 20 years;2) Compare the observed values to those calculated based on the algorithms of the spirometer used. Materials and Methods: The FVC and FEV values were first measured using a Micro Quark spirometer and then calculated from equations for the European Respiratory Society-93 (ERS-93) in 148 subjects, including 46 girls. In each age group, the measured values for the height of the subjects were considered the only variables used to calculate the equations for FVC and FEV with their 95% confidence intervals. The means of the FEV and FVC values were obtained by univariate analysis. Results: The calculated FEV and FVC values were significantly higher (p Conclusion: The correction factors incorporated in spirometers imported from Europe no longer seem appropriate to measure the physical characteristics of African subjects. The differences between the two methods of assessment should be used as new ethnic correction factors. 展开更多
关键词 Reference valueS correction Factors FORCED VITAL Capacity FORCED Expiratory Volume in One Second BENIN
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Multiplier Design Utilizing Tri Valued Logic for RLNS Based DSP Applications
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作者 Shalini Radakirishnan Valliammal Sampath Palaniswami 《Circuits and Systems》 2016年第4期417-433,共17页
Residue Number System (RNS) has proved shaping the Digital Signal Processing (DSP) units into highly parallel, faster and secured entities. The computational complexity of the multiplication process for a RNS based de... Residue Number System (RNS) has proved shaping the Digital Signal Processing (DSP) units into highly parallel, faster and secured entities. The computational complexity of the multiplication process for a RNS based design can be reduced by indulging Logarithmic Number System (LNS). The combination of these unusual number systems forms Residue Logarithmic Number System (RLNS) that provides simple internal architectures. Till date RLNS based processing units are designed for binary logic based circuits. In order to reduce the number of input output signals in a system, the concept of Multiple Valued Logic (MVL) is introduced in literature. In that course of research, this paper uses Tri Valued Logic (TVL) in RLNS technique proposed, to further reduce the chip area and delay value. Thus in this research work three different concepts are proposed, it includes the design of multiplier for RLNS based application for number of bits 8, 16 and 32. Next is the utilization of TVL in the proposed multiplication structure for RLNS based system along with the error correction circuits for the ternary logarithmic and antilogarithmic conversion process. Finally the comparison of the two multiplication schemes with the existing research of multiplier design for RNS based system using booth encoding concepts. It can be found that the proposed technique using TVL saves on an average of about 63% of area occupied and 97% of delay value respectively than the existing technique. 展开更多
关键词 Residue Number System (RNS) Residue Logarithmic Number System (RLNS) Tri valued Logic (TVL) Binary Logic Error correction Circuits
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Removing Random-Valued Impulse Noises by a Two-Staged Nonlinear Filtering Method
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作者 Ahmad Ashfaq Lu Yanting 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2016年第3期329-338,共10页
Digital images are frequently contaminated by impulse noise(IN)during acquisition and transmission.The removal of this noise from images is essential for their further processing.In this paper,a two-staged nonlinear f... Digital images are frequently contaminated by impulse noise(IN)during acquisition and transmission.The removal of this noise from images is essential for their further processing.In this paper,a two-staged nonlinear filtering algorithm is proposed for removing random-valued impulse noise(RVIN)from digital images.Noisy pixels are identified and corrected in two cascaded stages.The statistics of two subsets of nearest neighbors are employed as the criterion for detecting noisy pixels in the first stage,while directional differences are adopted as the detector criterion in the second stage.The respective adaptive median values are taken as the replacement values for noisy pixels in each stage.The performance of the proposed method was compared with that of several existing methods.The experimental results show that the performance of the suggested algorithm is superior to those of the compared methods in terms of noise removal,edge preservation,and processing time. 展开更多
关键词 image de-noising random-valued impulse noise nonlinear filter noisy pixel detection two-stage detection and correction method cascaded stages directional differences
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An Arbitrary Order Mixed Finite Element Method with Boundary Value Correction for the Darcy Flow on Curved Domains
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作者 Yongli Hou Yanqiu Wang 《Communications in Computational Physics》 2025年第5期1227-1249,共23页
We propose a boundary value correction method for the Brezzi-Douglas-Marini mixed finite element discretization of the Darcy flow with non-homogeneous Neumann boundary condition on 2D curved domains.The discretization... We propose a boundary value correction method for the Brezzi-Douglas-Marini mixed finite element discretization of the Darcy flow with non-homogeneous Neumann boundary condition on 2D curved domains.The discretization is defined on a body-fitted triangular mesh,i.e.the boundary nodes of the mesh lie on the curved physical boundary.However,the boundary edges of the triangular mesh,which are straight,may not coincide with the curved physical boundary.A boundary value correction technique is then designed to transform the Neumann boundary condition from the physical boundary to the boundary of the triangular mesh.One advantage of the boundary value correction method is that it avoids using curved mesh elements and thus reduces the complexity of implementation.We prove that the proposed method reaches optimal convergence for arbitrary order discretizations.Supporting numerical results are presented. 展开更多
关键词 Mixed finite element method Neumann boundary condition curved domain boundary value correction method
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地面接收系统G/T值的射电源测量方法及误差分析
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作者 周慧 王前 《无线电工程》 2026年第1期92-103,共12页
增益噪声温度比(Gain to Noise Temperature Ratio,G/T)是衡量卫星地面接收系统性能的关键指标,其测量精度直接影响系统性能评估的有效性。为提高G/T值的测量精度,系统阐述了利用射电源进行G/T值测试的原理和方法,提出了射电源大气吸收... 增益噪声温度比(Gain to Noise Temperature Ratio,G/T)是衡量卫星地面接收系统性能的关键指标,其测量精度直接影响系统性能评估的有效性。为提高G/T值的测量精度,系统阐述了利用射电源进行G/T值测试的原理和方法,提出了射电源大气吸收修正因子、波束展宽修正因子、射电源流量随时间变化修正因子的精确计算模型,并给出了射电源通量密度曲线及修正因子曲线。在此基础上,利用月亮和仙后座A对中等口径天线进行G/T值测量,系统分析了G/T值的测量误差,验证了所提计算模型的有效性,为提高G/T值测量的精确性与可靠性提供了科学依据和实践指导。 展开更多
关键词 增益噪声温度比 射电源 修正因子 误差分析
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白蛋白校正阴离子间隙对急性缺血性脑卒中患者静脉溶栓后出血转化结局的预测价值
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作者 黄维 彭祥旺 +2 位作者 王彩萍 陈智超 杨月 《疑难病杂志》 2026年第1期37-41,53,共6页
目的 探讨白蛋白校正阴离子间隙(ACAG)对急性缺血性脑卒中患者静脉溶栓后出血转化结局(HT)的预测价值。方法 选取2021年9月—2024年9月于南京医科大学附属明基医院行静脉溶栓治疗的急性缺血性脑卒中患者184例,依据溶栓治疗后48 h是否出... 目的 探讨白蛋白校正阴离子间隙(ACAG)对急性缺血性脑卒中患者静脉溶栓后出血转化结局(HT)的预测价值。方法 选取2021年9月—2024年9月于南京医科大学附属明基医院行静脉溶栓治疗的急性缺血性脑卒中患者184例,依据溶栓治疗后48 h是否出现HT分为HT组(n=39)和非HT组(n=145),入院第1天采集患者基线资料及相关实验室指标,采用多因素Logistic回归分析患者发生HT的影响因素,绘制受试者工作特征(ROC)曲线分析ACAG对缺血性脑卒中患者静脉溶栓后发生HT的预测价值。结果 HT组血氯(Cl^(-))、碳酸氢根(HCO_(3)^(-))、白蛋白(Alb)水平均低于非HT组(t/P=4.532/<0.001、5.017/<0.001、8.543/<0.001),HT组C反应蛋白(CRP)、阴离子间隙(AG)、ACAG水平均高于非HT组(t/P=11.351/<0.001、7.024/<0.001、11.205/<0.001);多因素Logistic回归分析结果显示,ACAG高(OR=14.145,95%CI 3.092~64.853)、AG高(OR=2.983,95%CI 1.866~4.771)、CRP高(OR=2.428,95%CI 1.104~12.127)、入院时NIHSS评分高(OR=3.147,95%CI 1.912~5.179)均为脑卒中患者静脉溶栓后发生HT的危险因素(P<0.01);ROC曲线分析结果显示,ACAG、AG、CRP及入院时NIHSS评分预测卒中患者发生HT的AUC分别为0.872、0.766、0.733、0.803,4项指标联合检测的AUC为0.915,显著高于各指标单独检测(Z/P=2.340/0.019、2.248/0.024、2.058/0.030、2.003/0.033)。结论 ACAG在预测急性缺血性脑卒中患者静脉溶栓后HT方面具有较高的效能,优于其他传统指标。 展开更多
关键词 急性缺血性脑卒中 静脉溶栓 出血转化 白蛋白校正阴离子间隙 预测价值
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Financial Valuation of Segment-Specific Marketing Activities and Market Segment Development
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作者 Heinz Eckart Klingelh6fer 《Journal of Modern Accounting and Auditing》 2012年第8期1140-1157,共18页
By applying methods of investment appraisal, this paper offers a financial approach for determining the optimal level of segment-specific marketing activities and market development under the conditions of imperfect m... By applying methods of investment appraisal, this paper offers a financial approach for determining the optimal level of segment-specific marketing activities and market development under the conditions of imperfect markets and uncertainty. Within the scope of marketing planning and controlling, the model is suited to optimizing an enterprise's market activities and taking interdependencies between market segments, production, and investments into account. Applying duality theory of linear programming allows for identifying the income determinants and deriving formulas for a correct valuation by using (corrected) net present values (NPVs). Under certain conditions, they can also be used to easily evaluate and financially interpret the effects of parameter changes. The author uses sensitivity analysis to support these findings and to obtain more information on the effects of these determinants. 展开更多
关键词 market segmentation market development financial valuation imperfect markets investment corrected) net present value income determinant segment-specific activity duality theory sensitivity analysis market share BUDGET production
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福建地区近震震级偏差研究
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作者 郭阳 李军 +2 位作者 金星 林彬华 蔡辉腾 《大地测量与地球动力学》 北大核心 2025年第3期266-272,共7页
基于福建数字地震台网编目资料,选取2010—2023年发生在福建地区的3720次地震,研究福建地区近震震级M_(L)偏差,采用震级残差法获得适用于福建地区的量规函数R_(3)(Δ)、台站校正值S_(j)和介质传播方向校正值S_(θ),以提高近震震级精度... 基于福建数字地震台网编目资料,选取2010—2023年发生在福建地区的3720次地震,研究福建地区近震震级M_(L)偏差,采用震级残差法获得适用于福建地区的量规函数R_(3)(Δ)、台站校正值S_(j)和介质传播方向校正值S_(θ),以提高近震震级精度。结果表明,校正后的震级偏差标准差从0.29降至0.19;为提高预警震级的准确性,应用首台震级测定,震级偏差标准差从0.31降至0.25。由此可见,新修订的量规函数、台站校正值和介质传播方向校正值在福建地区具有较强的适用性。 展开更多
关键词 震级偏差 量规函数 台站校正值 介质传播方向校正值 震级残差法
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加强知识治理:高校深化产教融合的新探索 被引量:1
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作者 曹海英 《教育理论与实践》 北大核心 2025年第30期8-12,共5页
高校产教融合是统筹服务教育强国、科技强国、人才强国建设,推动产业链、教育链、人才链、创新链等多链协同融合发展的主要抓手。高校产教融合共同体知识治理过程中,存在主体权责重新确定中的角色失衡、知识生产链在时间和空间面临解构... 高校产教融合是统筹服务教育强国、科技强国、人才强国建设,推动产业链、教育链、人才链、创新链等多链协同融合发展的主要抓手。高校产教融合共同体知识治理过程中,存在主体权责重新确定中的角色失衡、知识生产链在时间和空间面临解构风险、知识公共性与排他性的张力问题、知识创造活动的导向发生偏移等现实困境。高校产教融合共同体知识治理的创新路径是:以动态化的权责分配机制破解角色失衡,以弹性化的知识生产架构化解链条重构风险,以差异化的知识治理措施平衡知识属性张力,以系统性的价值纠偏遏制知识创造导向偏移。 展开更多
关键词 高校 产教融合共同体 知识治理 权责分配 知识生产 价值纠偏
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基于空间自回归模型和最大似然估计的非线性整数值统计推断方法 被引量:1
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作者 刘苏兵 尤游 《桂林航天工业学院学报》 2025年第3期423-432,共10页
当前整数值数据处理过程中,主要依靠连续型时间序列模型进行统计推断,操作过程中只能刻画数据线性特征,使得推断结果的标准化Pearson(皮尔森)残差较大。因此,文章提出基于空间自回归模型和最大似然估计的非线性整数值统计推断方法。应用... 当前整数值数据处理过程中,主要依靠连续型时间序列模型进行统计推断,操作过程中只能刻画数据线性特征,使得推断结果的标准化Pearson(皮尔森)残差较大。因此,文章提出基于空间自回归模型和最大似然估计的非线性整数值统计推断方法。应用H-RITNN(混合型鲁棒输入训练神经网络)非线性数据校正框架,将历史数据输入网络中,按照误差反传梯度下降法进行不断训练,找到异常数据并计算出校正值,完成观测样本数据预处理。利用给出数据样本建立残差空间自回归模型,描述数据包含的线性、非线性变化特点,并应用结合改进蚁群优化算法的最大似然估计算法求出模型未知参数,更新数据空间关系。以空间自回归模型为主,基于灰色理论的GM(1,1)模型和BP神经网络为辅,生成统计推断组合架构,基于此获取所需的非线性整数值。实验结果表明,新研究方法应用后给出的非线性整数值统计推断结果,标准化Pearson残差均值仅为0.02,证明其得出结果符合真实情况。 展开更多
关键词 数据校正 空间自回归模型 最大似然估计 门限参数 整数值 统计推断
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弹性五谱值布尔函数的构造与分析
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作者 王维琼 李越 +1 位作者 罗舒予 朱蒙蕊 《通信学报》 北大核心 2025年第7期145-154,共10页
五谱值布尔函数在码分多址(CDMA)通信、编码与密码、真随机数生成器(TRNG)与组合设计等领域中有重要应用。基于Walsh谱中和技术,提出了一类n元弹性五谱值布尔函数的直接构造法。证明了所构造的函数非线性度最高可达2^(n-1)-2^([n/2]),... 五谱值布尔函数在码分多址(CDMA)通信、编码与密码、真随机数生成器(TRNG)与组合设计等领域中有重要应用。基于Walsh谱中和技术,提出了一类n元弹性五谱值布尔函数的直接构造法。证明了所构造的函数非线性度最高可达2^(n-1)-2^([n/2]),达到该上界的函数代数次数为[n/2]+1,弹性阶约为[n+1/4],且校正阶为[n/2]。结果表明,所构造的函数达到了密码学指标的良好折中。 展开更多
关键词 布尔函数 五谱值函数 非线性度 弹性阶 校正阶
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条纹投影非线性误差主动编码最优估计校正方法
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作者 李茂月 徐敬之 +1 位作者 刘泽隆 黄思琦 《中国光学(中英文)》 北大核心 2025年第6期1365-1375,共11页
条纹投影技术在三维测量和表面形貌重建中得到广泛应用,其相位质量是决定测量精度的关键因素,而输入光强和输出光强之间的非线性效应是导致相位误差的主要来源之一。为了解决这一问题,本文提出了一种新的系统非线性主动校正方法。该方... 条纹投影技术在三维测量和表面形貌重建中得到广泛应用,其相位质量是决定测量精度的关键因素,而输入光强和输出光强之间的非线性效应是导致相位误差的主要来源之一。为了解决这一问题,本文提出了一种新的系统非线性主动校正方法。该方法首先通过对标准平面投影少量的均匀灰度图像,获取输入光强与输出光强的变化规律。然后,将这一规律与系统非线性主动校正相结合,建立了基于输入输出光强变化的系统非线性模型。接着,利用遗传算法求解最优编码值,从而通过条纹编码主动校正了投影条纹。经过校正后的条纹有效减少了非线性效应带来的影响,大幅提升了相位获取的质量。为了验证所提方法的有效性,以三步相移为例进行了计算机仿真。结果表明,标准误差降低了88%,最大误差减少了85.5%。在实际标准平面实验中,校正后标准相位误差由0.0706 rad降至0.0168 rad,最大相位误差由0.4129 rad降至0.0960 rad。在人脸石膏模型实验中,校正后的标准相位误差由0.0472 rad降至0.0102 rad,最大相位误差由0.2990 rad降至0.2408 rad。在复杂形貌人脸石膏件的三维重建中,校正后表面质量得到显著提升,影响相位质量的水波纹效应大幅减小。与现有的大步相移方法相比,本文提出的方法不仅具有较高的相位获取精度,而且在所需数据量和操作便捷性方面也具有明显优势,显示出广泛的应用前景。 展开更多
关键词 非线性校正 条纹投影 最优值估计 相位质量 结构光测量
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从驱离到共生:复合运动主体的生成与完整性重塑
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作者 董传升 高晓驰 《武汉体育学院学报》 北大核心 2025年第11期1-9,共9页
探讨体育领域中由技术与运动主体深度融合形成的“复合运动主体”的生成、异化风险及完整性重塑。研究认为,技术通过具身性、历史性与动态性辩证关系深度嵌入运动主体,拓展其潜能,但也引发技术理性盲从、技术自主僭越及本真意向丢失等... 探讨体育领域中由技术与运动主体深度融合形成的“复合运动主体”的生成、异化风险及完整性重塑。研究认为,技术通过具身性、历史性与动态性辩证关系深度嵌入运动主体,拓展其潜能,但也引发技术理性盲从、技术自主僭越及本真意向丢失等异化危机。这源于技术对人主体人文性和价值性的一种驱离。为了消解技术异化,重构复合运动主体的完整性,提出“人本复归”与“价值纠偏”路径,在运动主体层面推动人本复归,在制度规范层面实施价值纠偏,最终通过“人机共生”实现复合运动主体从技术驱离到完整性重塑的转向,捍卫体育作为表达人之主体性增强的意义。 展开更多
关键词 完整性重塑 复合运动主体 技术异化 技术增强 人本复归 价值纠偏
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“躺平文化”对大学生价值观的异化及矫治策略
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作者 李静 《金华职业技术大学学报》 2025年第4期1-6,共6页
在互联网的催化下,“躺平”思想逐渐从网络蔓延到现实社会,引得部分人的认同和效仿,推动着“躺平文化”的兴起。在“躺平文化”的影响下,部分大学生的价值观念正经历着一场深刻的变革,表现为对劳动精神、职业选择、婚恋意愿、集体观念... 在互联网的催化下,“躺平”思想逐渐从网络蔓延到现实社会,引得部分人的认同和效仿,推动着“躺平文化”的兴起。在“躺平文化”的影响下,部分大学生的价值观念正经历着一场深刻的变革,表现为对劳动精神、职业选择、婚恋意愿、集体观念和消费欲望的价值取向异化。其中,“躺平即正义”的言论误导、“先躺为敬”的心理蔓延、“不争不抢”的消极姿态、“一躺到底”的生存样态,构成了大学生价值观异化成因的复杂图景。对此,需要从构建正向社会竞争生态、深化主流价值观教育、净化网络舆论空间和加强自我认知教育等方面入手矫治,从而引导大学生从“躺平”中坐起来、站起来、干起来。 展开更多
关键词 躺平文化 大学生 价值观异化 矫治策略
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重型破冰船船体梁波浪载荷数值计算研究
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作者 苏楠 《船舶》 2025年第5期62-70,共9页
重型破冰船的长宽比(L/B)一般为4~5,故常规的船体梁波浪载荷规范计算公式适用性受限,且重型破冰船的船体型线特征与开敞水域航行的船舶有显著不同,因此需利用数值方法研究其船体梁波浪载荷特性。该文基于有航速时域Rankine源法,采用水... 重型破冰船的长宽比(L/B)一般为4~5,故常规的船体梁波浪载荷规范计算公式适用性受限,且重型破冰船的船体型线特征与开敞水域航行的船舶有显著不同,因此需利用数值方法研究其船体梁波浪载荷特性。该文基于有航速时域Rankine源法,采用水动力软件WASIM对其船体梁波浪载荷进行预报,得到了波浪载荷线性长期值和波浪载荷非线性直接计算值;随后,将波浪载荷线性长期值(非线性修正后)、波浪载荷非线性直接计算值,分别与规范值进行对比。结果表明:由于其船体型线特殊,垂向波浪载荷弯矩线性长期值约为规范线性值的1.4倍,垂向波浪剪力线性长期值约为规范线性值的1.9倍,规范公式无法对其船体梁波浪载荷进行合理的评估;基于工程设计的实际出发,建议取5 kn航速下垂向波浪载荷线性长期值(非线性修正后)作为船体梁波浪设计载荷,用于船体结构总强度评估;中垂波浪弯矩载荷非线性效应显著,在对中垂状态下的船体进行总纵强度校核时,应特别关注长上层建筑的结构屈曲问题。 展开更多
关键词 重型破冰船 船体梁波浪载荷 非线性效应 线性值 非线性修正系数
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武山县生态系统服务价值时空变化分析 被引量:2
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作者 刘杰 刘学录 +4 位作者 刘星雨 白永刚 包瑾 张晓丽 惠彩虹 《甘肃农业大学学报》 北大核心 2025年第2期276-286,共11页
【目的】对武山县生态系统服务价值(ESV)进行科学评估,并分析其时空分异特征和影响因素。【方法】基于1990年、2000年、2010年以及2020年4期LUCC遥感监测数据,采用土地利用动态分析、价值当量因子评估和修正等方法,以县域为单位对武山... 【目的】对武山县生态系统服务价值(ESV)进行科学评估,并分析其时空分异特征和影响因素。【方法】基于1990年、2000年、2010年以及2020年4期LUCC遥感监测数据,采用土地利用动态分析、价值当量因子评估和修正等方法,以县域为单位对武山县生态系统服务价值时空变化规律进行研究。【结果】1990~2020年,武山县土地利用类型以草地为主,占总面积的45%以上,林地面积增加最大,为49343.19 hm^(2),草地面积大幅度减少,为78190.73 hm^(2)。武山县生态系统服总务价值变化比较稳定,整体呈现增加的变化趋势,期间共增加0.67亿元。根据武山县各生态系统服务的价值和变动情况可知,武山县的生态系统服务是以调整服务和支持服务为主的,且以水文调节和气候调节为主要部分,在总价值中所占比重超过44%。【结论】研究区的生态系统服务价值量主要来自:气候调节、水文调节、土壤保持等功能,林地与草地面积的变化是研究区生态系统服务价值变化的重要影响因素;生态系统服务价值时空分布与土地利用结构之间存在密切关系,林地和水域具有较高的生态系统服务价值。 展开更多
关键词 生态系统服务价值(ESV) 武山县 系数修正
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