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Construction theory of dyadic scale function and dyadic wavelet function
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作者 冉启文 冯英浚 孙学全 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2000年第4期25-27,共3页
We derive the conditions for the existence of the unique solution of the two scale integral equation and the form of the solution, according to the method of the construction of the dyadic scale function. We give the ... We derive the conditions for the existence of the unique solution of the two scale integral equation and the form of the solution, according to the method of the construction of the dyadic scale function. We give the construction of the dyadic wavelet and its necessary and sufficient condition. As an application, we also develop a pyramid algorithm of the dyadic wavelet decomposition. 展开更多
关键词 two scale INTEGRAL equation DYADIC WAVELET function DYADIC scale function PYRAMID algorithm
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Laguerre Series Expansion for Scale Functions and Its Applications in Risk Theory
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作者 Jia-yi XIE Zhen-yu CUI Zhi-min ZHANG 《Acta Mathematicae Applicatae Sinica》 2026年第1期146-162,共17页
We propose an exact explicit closed-form Laguerre series expansion formula to compute the q-scale function of a spectrally negative Lévy process(SNLP),and other functions associated to the scale function for the ... We propose an exact explicit closed-form Laguerre series expansion formula to compute the q-scale function of a spectrally negative Lévy process(SNLP),and other functions associated to the scale function for the first time.The proposed closed-form formula for the scale function has many applications in applied probability and in particular in the Lévy insurance risk theory.We shall show that the new series expansion formulas can be used to express the expected discounted penalty functions,the moments of the present value of total dividend payments as well as the time value of Parisian ruin in the Lévy risk models. 展开更多
关键词 Laguerre series scale function spectrally negative Lévy process ruin probability
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Stable computations of the spherically layered media theory with high lossy media by using scaled Bessel functions
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作者 Jia-Hui Wang Bo O.Zhu 《Journal of Electronic Science and Technology》 2025年第1期22-34,共13页
The spherically layered media theory has wide applications for electromagnetic wave scattering analysis.Due to the involved Bessel functions,the conventional formulations of spherically layered media theory suffer fro... The spherically layered media theory has wide applications for electromagnetic wave scattering analysis.Due to the involved Bessel functions,the conventional formulations of spherically layered media theory suffer from numerical overflow or underflow when the Bessel function’s order is large,the argument is small or the argument has a large imaginary part.The first two issues have been solved recently by employing small-argument asymptotic formulas of Bessel functions,while the third issue remains unsolved.In this paper,the Bessel functions in the conventional formulation of the theory are replaced by scaled Bessel functions which have good numerical properties for high loss media,and stable formulas are derived.Numerical tests show that this approach can work properly with very high lossy media.Also,this approach can be seamlessly combined with the stable computation method for cases of small argument and large order of Bessel functions. 展开更多
关键词 Lossy media Numerical stability scaled Bessel function Spherically layered media theory
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POLY-SCALE REFINABLE FUNCTION AND THEIR PROPERTIES
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作者 杨守志 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2006年第12期1687-1695,共9页
Poly-scale refinable function with dilation factor a is introduced. The existence of solution of poly-scale refinable equation is investigated. Specially, necessary and sufficient conditions for the orthonormality of ... Poly-scale refinable function with dilation factor a is introduced. The existence of solution of poly-scale refinable equation is investigated. Specially, necessary and sufficient conditions for the orthonormality of solution function Ф of poly-scale refinable equation with integer dilation factor a are established. Some properties of poly-scale refinable function are discussed. Several examples illustrating how to use the method to construct poly-scale refinable function are given. 展开更多
关键词 poly-scale function dilation factor poly-scale functional equation
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Gait and Glasgow Coma Scale scores can predict functional recovery in patients with traumatic brain injury 被引量:3
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作者 Sevil Bilgin Arzu Guclu-Gunduz +2 位作者 Hakan Oruckaptan Nezire Kose Bülent Celik 《Neural Regeneration Research》 SCIE CAS CSCD 2012年第25期1978-1984,共7页
Fifty-one patients with mild (n -- 14), moderate (n = 10) and severe traumatic brain injury (n = 27) received early rehabilitation. Level of consciousness was evaluated using the Glasgow Coma Score Functional le... Fifty-one patients with mild (n -- 14), moderate (n = 10) and severe traumatic brain injury (n = 27) received early rehabilitation. Level of consciousness was evaluated using the Glasgow Coma Score Functional level was determined using the Glasgow Outcome Score, whilst mobility was evaluated using the Mobility Scale for Acute Stroke. Activities of daily living were assessed using the Barthel Index. Following Bobath neurodevelopmental therapy, the level of consciousness was significantly improved in patients with moderate and severe traumatic brain injury, but was not greatly influenced in patients with mild traumatic brain injury. Mobility and functional level were significantly improved in patients with mild, moderate and severe traumatic brain injury. Gait recovery was more obvious in patients with mild traumatic brain injury than in patients with moderate and severe traumatic brain injury. Activities of daily living showed an improvement but this was insignificant except for patients with severe traumatic brain injury. Nevertheless, complete recovery was not acquired at discharge. Multiple regression analysis showed that gait and Glasgow Coma Scale scores can be considered predictors of functional outcomes following traumatic brain injury. 展开更多
关键词 brain injury traumatic brain injury REHABILITATION early rehabilitation function PROGNOSIS GlasgowComa scale Glasgow Outcome scale functional level neural regeneration
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Multi-scale analysis of the spatial structure of China’s major function zoning 被引量:10
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作者 WANG Yafei FAN Jie 《Journal of Geographical Sciences》 SCIE CSCD 2020年第2期197-211,共15页
The spatial structures of China’s Major Function Zoning are important constraining indicators in all types of spatial planning and key parameters for accurately downscaling major functions.Taking the proportion of ur... The spatial structures of China’s Major Function Zoning are important constraining indicators in all types of spatial planning and key parameters for accurately downscaling major functions.Taking the proportion of urbanization zones,agricultural development zones and ecological security zones as the basic parameter,this paper explores the spatial structures of major function zoning at different scales using spatial statistics,spatial modeling and landscape metrics methods.The results show:First,major function zones have spatial gradient structures,which are prominently represented by latitudinal and longitudinal gradients,a coastal distance gradient,and an eastern-central-western gradient.Second,the pole-axis system structure and core-periphery structure exist at provincial scales.The general principle of the pole-axis structure is that as one moves along the distance axis,the proportion of urbanization zones decreases and the proportion of ecological security zones increases.This also means that the proportion of different function zones has a ring-shaped spatial differentiation principle with distance from the core.Third,there is a spatial mosaic structure at the city and county scale.This spatial mosaic structure has features of both spatial heterogeneity,such as agglomeration and dispersion,as well as of mutual,adjacent topological correlation and spatial proximity.The results of this study contribute to scientific knowledge on major function zones and the principles of spatial organization,and it acts as an important reference for China’s integrated geographical zoning. 展开更多
关键词 China major function zoning MULTI-scale spatial gradient pole-axis CORE-PERIPHERY spatial mosaic
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Positively Worded Subscale Score of the Perceived Stress Scale Is Associated with Cognitive Domain Function
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作者 Julie M. Jiang Elizabeth K. Seng +2 位作者 Molly E. Zimmerman Mimi Kim Richard B. Lipto 《Journal of Behavioral and Brain Science》 2017年第7期311-324,共14页
Objectives: To examine the cross-sectional associations of the separate subscales of the Perceived Stress Scale (PSS) and tests measuring cognitive domains in older adults. Methods: 897 adults over the age of 70 free ... Objectives: To examine the cross-sectional associations of the separate subscales of the Perceived Stress Scale (PSS) and tests measuring cognitive domains in older adults. Methods: 897 adults over the age of 70 free of amnestic mild cognitive impairment and dementia and enrolled in the Einstein Aging Study made up the study sample. The PSS-14 was used to measure stress. Three cognitive domains (language, episodic memory, and frontal-executive) had previously been found using principle component analysis. Linear regression analyses were used to determine the relationship between the PSS subscales and cognitive domain function. Results: The study sample had a mean age of 79.1 years and 62.8% were female. Bivariate correlations show that the PSS-14 positively worded subscale of the PSS (PSS-PW) was significantly associated with all three cognitive domains (language: r = -0.15, p < 0.001;episodic memory: r = -0.16, p < 0.001;frontal-executive: r = -0.21, p <0.001) while the negatively worded subscale of the PSS (PSS-NW) was not significantly associated with any cognitive domain. In linear regression analyses adjusted for age, white race, gender, years of education, and depressive symptoms, the PSS-PW remained significantly associated with each of the cognitive domains. The PSS-NW was not associated with any cognitive domains in any model. The PSS-14 was significantly associated with language and episodic memory, but not the frontal-executive domain. Conclusion: Worse PSS-PW scores are associated with reduced cognitive function in the executive, memory, and language domains in nondemented older adults. The PSS-PW subscale correlated better with cognitive function than the overall PSS-14. Future research should evaluate the temporality of the association and if stress reduction therapies improve cognitive performance. 展开更多
关键词 PERCEIVED STRESS scale Cognitive Domain function CROSS-SECTIONAL PERCEIVED STRESS scale Subscales
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GU'S FUNCTION SCALE OF ION HYDRATION FORCE AND CHARGE SIZE
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作者 顾宏堪 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 1997年第2期186-191,共6页
Water Vapor Chemistry" as a new science was discovered and established from trace analysis in Gu’s laboratory(Gu, 1991; Gu et al., 1991). Gu’s Function shows that the trace metal ion concentration in water vapo... Water Vapor Chemistry" as a new science was discovered and established from trace analysis in Gu’s laboratory(Gu, 1991; Gu et al., 1991). Gu’s Function shows that the trace metal ion concentration in water vapor has positive correlation to"specific electron affinity constant"last ionization potential Iz/ion valence Z and negative correlation to ion volume V and coordination number N(Gu, 1994). Gu’s Func-tion C=f[(Iz/Z)/VN]of the bond parameter in water vapor chemistry corresponds to the potential energy function Z’ e2/r in the Schrodinger Equation of quantum chemistry. In different ions with the same 2+ charge, the ion concentration of water-water vapor transfer may be much different. This shows that the 2+ charge of different ions has different attractive force (hydration force). This different attractive force of the charge can be scaled with the relative energy or charge size from Gu’s Function. 展开更多
关键词 water vapor chemistry Gu′s function scale ION hydration FORCE ION CHARGE SIZE
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Quadratic Lyapunov Function and Exponential Dichotomy on Time Scales
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作者 ZHANG JI LIU ZHEN-XIN 《Communications in Mathematical Research》 CSCD 2011年第1期24-36,共13页
In this paper, we study the relationship between exponential dichotomy and quadratic Lyapunov function for the linear equation x△=A(t)x on time scales. Moreover, for the nonlinear perturbed equation x△= A(t)x ... In this paper, we study the relationship between exponential dichotomy and quadratic Lyapunov function for the linear equation x△=A(t)x on time scales. Moreover, for the nonlinear perturbed equation x△= A(t)x + f(t, x) we give the instability of the zero solution when f is sufficiently small. 展开更多
关键词 quadratic Lyapunov function exponential dichotomy time scale INSTABILITY
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EXISTENCE OF PERIODIC SOLUTIONS TO A SYSTEM WITH FUNCTIONAL RESPONSE ON TIME SCALES
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作者 Zhenjie Liu 《Analysis in Theory and Applications》 2009年第4期369-380,共12页
This paper investigates the existence of periodic solutions of a three-species food-chain diffusive system with Beddington-DeAngelis functional responses and time delays in a two-patch environment on time scales. By u... This paper investigates the existence of periodic solutions of a three-species food-chain diffusive system with Beddington-DeAngelis functional responses and time delays in a two-patch environment on time scales. By using a continuation theorem based on coincidence degree theory, we obtain sufficient criteria for the existence of periodic solutions for the system. Moreover, when the time scale T is chosen as R or Z, the existence of the periodic solutions of the corresponding continuous and discrete models follows. Therefore, the method is unified to provide the existence of the desired solutions for continuous differential equations and discrete difference equations. 展开更多
关键词 time scale food-chain system Beddington-DeAngelis functional response diffusion coincidence degree
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基于改进YOLO11n模型的自动驾驶道路交通检测算法研究
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作者 田晟 赵凯龙 苗佳霖 《广西师范大学学报(自然科学版)》 北大核心 2026年第1期1-9,共9页
随着自动驾驶技术的快速发展,道路交通检测作为感知模块的核心任务,直接影响自动驾驶系统的安全性与可靠性,当前基于深度学习方法作为研究的热点,却仍存在检测精度低、模型泛化性差等问题。为解决这些问题,本文提出一种改进YOLO11n模型... 随着自动驾驶技术的快速发展,道路交通检测作为感知模块的核心任务,直接影响自动驾驶系统的安全性与可靠性,当前基于深度学习方法作为研究的热点,却仍存在检测精度低、模型泛化性差等问题。为解决这些问题,本文提出一种改进YOLO11n模型的道路交通检测方法。该方法通过增加小目标检测层提高对小目标的检测精度,引入GhostConv+DWConv检测头结构,组合优化现有的双DWConv结构,并设计更适合小目标的Inner-CIoU损失函数,增强模型的泛化性,提高边界框回归的准确性。实验结果显示,与现有YOLO11n算法相比,该模型在KITTI和BDD100K数据集上的检测精度分别提升1.1个百分点和1.9个百分点,并达到125帧/s和124帧/s的检测速度,提升了低分辨率小目标检测的有效性,在不同交通场景下具有良好的泛化性。 展开更多
关键词 自动驾驶 小目标检测 YOLO11 多尺度检测 损失函数
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基于脑电多尺度特征和图神经网络的紧急制动行为识别
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作者 闫光辉 黄霄 常文文 《浙江大学学报(工学版)》 北大核心 2026年第2期404-414,共11页
现有技术主要依赖传统的时频域特征,对脑活动空间域特征的研究不足.为了实现对紧急制动意图和正常驾驶的分类识别,提出融合多尺度卷积、脑功能网络和图卷积神经网络的新模型.利用多尺度卷积提取时频域融合的多尺度特征;基于脑功能连接... 现有技术主要依赖传统的时频域特征,对脑活动空间域特征的研究不足.为了实现对紧急制动意图和正常驾驶的分类识别,提出融合多尺度卷积、脑功能网络和图卷积神经网络的新模型.利用多尺度卷积提取时频域融合的多尺度特征;基于脑功能连接测量矩阵构建脑功能网络,得到空间图结构信息;采用图卷积神经网络融合多尺度特征和空间图结构信息,实现对紧急制动脑电信号的分类识别.实验结果表明,所提模型在公开数据集上多被试的准确率均超过93.00%,最高达到95.60%;在单被试条件下,准确率均超过92.00%,最高达到98.94%.消融实验验证了所提模型各模块均对模型性能的提升具有显著贡献.在相同数据集下,所提模型比已有的6种脑电信号分类算法更具优势. 展开更多
关键词 紧急制动 脑电信号(EEG) 多尺度特征 脑功能网络 图卷积神经网络
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基于多尺度注意力的无人机红外图像目标检测方法
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作者 朱磊 赵兴瑞 李光健 《红外技术》 北大核心 2026年第3期298-304,共7页
无人机拍摄的红外图像纹理信息少、边缘特征弱,常导致轻量型网络对红外图像中的小尺度目标检测精度提升困难,为此,提出了一种基于多尺度注意力的轻量型无人机红外目标检测网络方法UIDNet。该方法在YOLOv8网络基础上,首先对原网络最后一... 无人机拍摄的红外图像纹理信息少、边缘特征弱,常导致轻量型网络对红外图像中的小尺度目标检测精度提升困难,为此,提出了一种基于多尺度注意力的轻量型无人机红外目标检测网络方法UIDNet。该方法在YOLOv8网络基础上,首先对原网络最后一层下采样进行裁剪,在降低网络参数量的同时改善过深的卷积神经网络导致的小目标细节特征丢失问题;然后,基于跨空间学习的高效多尺度注意力(Efficient Multi-Scale Attention,EMA)构造特征提取模块C2f-EMA,通过通道重塑和维度分组在抑制背景环境干扰的同时,最大程度保留并突出小目标特征;最后,引入WIoU损失函数代替原网络CIoU损失函数,实现目标权重的动态调整,以进一步提高网络对小目标的检测性能。实验结果表明,与YOLOv8n和PiCoDet等其他先进网络在HIT-UAV数据集上相比,UIDNet拥有更小的模型体积与更好的检测效果,相对于原YOLOv8n模型,UIDNet的平均检测精度提升了1.7%,参数量减少了67.4%,模型体积压缩了63.5%,仅为2.3 MB。 展开更多
关键词 红外图像目标检测 YOLOv8 多尺度注意力 WIoU损失函数
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学前儿童执行功能教师评估量表的编制
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作者 谢腾 刘丁玉 《龙岩学院学报》 2026年第2期105-113,共9页
为解决现有工具在评估学前儿童个体差异及文化适用性方面的局限,开发一款由教师评估的执行功能标准化量表。通过教师访谈与文献回顾构建初始条目,经四轮德尔菲法修订确保内容效度,并对预试量表进行项目分析和探索性因子分析,筛选题项并... 为解决现有工具在评估学前儿童个体差异及文化适用性方面的局限,开发一款由教师评估的执行功能标准化量表。通过教师访谈与文献回顾构建初始条目,经四轮德尔菲法修订确保内容效度,并对预试量表进行项目分析和探索性因子分析,筛选题项并探索其结构,形成20题正式量表进行全面的信效度检验。结果表明,该量表包含灵活变通、抑制控制和工作记忆三个维度,结构稳定且模型拟合良好。量表具有良好的信度并与效标量表BRIEF-P显著相关,符合测量标准。可为学前教育工作者及研究者评估儿童执行功能、制定干预策略提供科学支持。 展开更多
关键词 学前儿童执行功能 教师评估量表 儿童认知发展 心理测量学验证 行为评估
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基于多尺度卷积和通道注意力机制的网络流量异常检测方法
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作者 付钰 王玉珏 +2 位作者 俞艺涵 刘涛涛 安义帅 《通信学报》 北大核心 2026年第1期184-200,共17页
针对传统网络流量异常检测方法受限于模型表达能力较弱、数据类不平衡等问题,提出了一种融合多尺度卷积与通道注意力机制的网络流量异常检测方法。首先,设计金字塔卷积模块捕捉网络流量的多尺度特征,有效提升分类性能;其次,利用通道注... 针对传统网络流量异常检测方法受限于模型表达能力较弱、数据类不平衡等问题,提出了一种融合多尺度卷积与通道注意力机制的网络流量异常检测方法。首先,设计金字塔卷积模块捕捉网络流量的多尺度特征,有效提升分类性能;其次,利用通道注意力机制增强模型对异常流量敏感特征的通道响应,提高特征的可辨别性,从而抑制噪声干扰;最后,通过改进均衡损失函数调整不同类别权重系数,从而缓解数据集中的类不平衡问题。在NSL-KDD和CIC-IDS-2017数据集上开展了一系列实验,实验结果表明,所提方法取得了较好的分类结果,准确率分别为99.45%和99.95%,同时误报率仅为0.50%和0.02%。 展开更多
关键词 网络流量异常检测 多尺度卷积 注意力机制 均衡损失函数
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新质生产力与多功能大循环农业的辩证发展逻辑
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作者 董军 田培沛 《合肥工业大学学报(社会科学版)》 2026年第1期42-50,共9页
新质生产力是高科技、绿色、先进生产力,多功能大循环农业是一种集智慧循环、生态安全、多业融合的新型农业。二者辩证创新发展:系统整体层面,新质生产力推动多功能大循环农业提高生产效率,形成新动能、新业态,多功能大循环农业为新质... 新质生产力是高科技、绿色、先进生产力,多功能大循环农业是一种集智慧循环、生态安全、多业融合的新型农业。二者辩证创新发展:系统整体层面,新质生产力推动多功能大循环农业提高生产效率,形成新动能、新业态,多功能大循环农业为新质生产力提供国内、国际、全球的发展运用平台;结构要素层面,新质生产力促进多功能大循环农业从业内融合、业间融合到产业升级,而多功能大循环农业反哺新质生产力要素中的科技创新发展,从科技创新、科技普及到形成社会科技创新生态。新质生产力与多功能大循环农业的辩证创新发展实践,既体现了农业经济发展与生态环境保护的辩证运动发展规律,又为中国农业现代化的发展提供新思路。 展开更多
关键词 新质生产力 多功能大循环农业 生态 科技 可持续发展
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Evaluation of Differential Item Functioning of the Center of Epidemiological Scale Depression Revisited for Gender in Mexican Adolescents
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作者 Jesus Rafael Osomo Mungula Herminia Beatriz Segura Celis Ochoa +1 位作者 Alma Gloria Vallejo Casarin Patricia Andrade Palos 《Psychology Research》 2013年第4期232-241,共10页
关键词 性别差异 流行病学 抑郁症 青少年 墨西哥 评价 研究人员 项目运作
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农村劳动力转移、农地规模经营与农业碳排放
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作者 侯力 田佳蔚 《人口学刊》 北大核心 2026年第2期116-128,共13页
在实现“双碳”战略目标的过程中,第一产业同样发挥着至关重要的作用。随着我国农村劳动力转移规模的不断扩大,农村劳动力转移作为人口因素对农业碳排放具有深远影响,厘清农村劳动力转移、农地规模经营与农业碳排放之间的相关联系对推... 在实现“双碳”战略目标的过程中,第一产业同样发挥着至关重要的作用。随着我国农村劳动力转移规模的不断扩大,农村劳动力转移作为人口因素对农业碳排放具有深远影响,厘清农村劳动力转移、农地规模经营与农业碳排放之间的相关联系对推动我国农业现代化转型和促进低碳农业绿色发展有着重要的理论和现实意义。本文聚焦农地规模经营这一作用机制,从理论上剖析农村劳动力转移如何通过农地规模经营影响农业碳排放。基于我国2001—2021年31个省(区、市)的平衡面板数据,构建双向固定效应模型,探讨农村劳动力转移对农业碳排放的影响并进行实证分析,同时构建中介效应模型进一步研究农地规模经营在农村劳动力转移与农业碳排放这二者之间的具体作用机制和传导路径,使用Sobel边缘检测法和Bootstrap抽样法对中介效应进行检验。实证分析结果显示中国农村劳动力转移会显著抑制农业碳排放增加,并通过替换被解释变量、剔除直辖市数据和更换计量模型的方法进行稳健性检验,证明实证结果的稳健性。采用工具变量法结合两阶段最小二乘法进行内生性检验,有效缓解模型中可能存在的遗漏变量等内生性问题后,研究结论依然成立。农村劳动力转移对农业碳排放的影响存在空间异质性特征,从功能区位、地理区位和种植结构三个角度进行异质性分析,在粮食主产区、东部地区和以粮食作物种植为主的地区农村劳动力转移对农业碳排放的抑制效果更加明显。影响机制检验结果表明农地规模经营是农村劳动力转移实现农业碳减排的重要传导路径,农村劳动力转移能够通过农地规模经营减少农业碳排放。基于研究结论得到以下政策启示:第一,积极推进新型城镇化建设,合理引导农村劳动力转移,不断完善对农村劳动力转移就业扶持政策,有序引导农村劳动力向非农部门转移,同时对于不同地区农村劳动力转移应采取差异化思路;第二,适度扩大农业经营规模,促进农业生产规模化和集约化经营管理方式,高效利用农业各生产要素,提高农村劳动生产率和农业资源利用效率,促进农业节能减排技术广泛普及,加快实现农业碳减排。 展开更多
关键词 农村劳动力转移 农地规模经营 农业碳排放 粮食生产功能区 种植结构
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铁路扣件多缺陷识别的改进 YOLOv5s 检测算法
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作者 李磊 连正浦 +2 位作者 李怡迩 孙建锋 高硕学 《实验室研究与探索》 北大核心 2026年第3期100-108,127,共10页
针对铁路钢轨扣件缺陷检测中存在漏检、误检及模型复杂度高等问题,提出一种用于铁路扣件多缺陷识别的改进YOLOv5s算法。该算法设计了双向减权多尺度特征融合(BiDW-MFF)结构作为YOLOv5s的颈部网络,以增强多尺度特征提取能力;构建C3-ST-Re... 针对铁路钢轨扣件缺陷检测中存在漏检、误检及模型复杂度高等问题,提出一种用于铁路扣件多缺陷识别的改进YOLOv5s算法。该算法设计了双向减权多尺度特征融合(BiDW-MFF)结构作为YOLOv5s的颈部网络,以增强多尺度特征提取能力;构建C3-ST-Res模块替换部分C3模块,从而降低模型参数量;设计了一种动态损失函数SDIoU,通过引入自适应权重机制提升边界框回归精度。实验结果表明,改进后模型的平均检测精度达到91.7%,较原YOLOv5s提升11.5个百分点,且参数量与权重大小分别降低4.2%和3.5%。与SSD、Faster R-CNN及YOLOv3等主流算法相比,所提算法在检测性能与模型效率方面均表现出明显优势,可为钢轨扣件缺陷智能检测提供有效技术支撑。 展开更多
关键词 铁路扣件 C3-ST-Res模块 双向减权多尺度特征融合 SDIoU动态损失函数
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A Note on an Economic Lot-sizing Problem with Perishable Inventory and Economies of Scale Costs:Approximation Solutions and Worst Case Analysis 被引量:2
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作者 Qing-Guo Bai Yu-Zhong Zhang Guang-Long Dong 《International Journal of Automation and computing》 EI 2010年第1期132-136,共5页
This paper presents an economic lot-sizing problem with perishable inventory and general economies of scale cost functions. For the case with backlogging allowed, a mathematical model is formulated, and several proper... This paper presents an economic lot-sizing problem with perishable inventory and general economies of scale cost functions. For the case with backlogging allowed, a mathematical model is formulated, and several properties of the optimal solutions are explored. With the help of these optimality properties, a polynomial time approximation algorithm is developed by a new method. The new method adopts a shift technique to obtain a feasible solution of subproblem and takes the optimal solution of the subproblem as an approximation solution of our problem. The worst case performance for the approximation algorithm is proven to be (4√2 + 5)/7. Finally, an instance illustrates that the bound is tight. 展开更多
关键词 Economic lot-sizing problem BACKLOGGING economies of scale function PERISHABLE approximation algorithm
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