期刊文献+
共找到81,687篇文章
< 1 2 250 >
每页显示 20 50 100
Integrating wind field analysis in UAV path planning:Enhancing safety and energy efficiency for urban logistics
1
作者 Ruijia GU Yifei ZHAO Xinhui REN 《Chinese Journal of Aeronautics》 2026年第1期508-533,共26页
Shenzhen,a major city in southern China,has experienced rapid advancements in Unmanned Aerial Vehicle(UAV)technology,resulting in extensive logistics networks with thousands of daily flights.However,frequent disruptio... Shenzhen,a major city in southern China,has experienced rapid advancements in Unmanned Aerial Vehicle(UAV)technology,resulting in extensive logistics networks with thousands of daily flights.However,frequent disruptions due to its subtropical monsoon climate,including typhoons and gusty winds,present ongoing challenges.Despite the growing focus on operational costs and third-party risks,research on low-altitude urban wind fields remains scarce.This study addresses this gap by integrating wind field analysis into UAV path planning,introducing key innovations to the classical model.First,UAV wind resistance and turbulence constraints are analyzed,mapping high-wind-speed and turbulence-prone zones in the airspace.Second,wind dynamics are incorporated into path planning by considering airspeed and groundspeed variation,optimizing waypoint selection and flight speed adjustments to improve overall energy efficiency.Additionally,a wind-aware Theta*algorithm is proposed,leveraging wind vectors to expedite search process,while Computational Fluid Dynamics(CFD)techniques are employed to calculate wind fields.A case study of Shenzhen,examining wind patterns over the past decade,demonstrates a 6.23%improvement in groundspeed and a 7.69%reduction in energy consumption compared to wind-agnostic models.This framework advances UAV logistics by enhancing route safety and energy efficiency,contributing to more cost-effective operations. 展开更多
关键词 Drone logistics Energy consumption Hazardous field region Path planning Unmanned aerial vehicle(UAV) Urban wind fields
原文传递
临床-超声多因素Logistic回归模型在鉴别非弥漫型原发性甲状腺淋巴瘤与甲状腺乳头状癌中的临床价值
2
作者 张海欢 侯红梅 +2 位作者 闫荟同 李维生 李琴 《临床和实验医学杂志》 2026年第1期102-105,共4页
目的探讨临床-超声多因素Logistic回归模型在鉴别非弥漫型原发性甲状腺淋巴瘤(PTL)与甲状腺乳头状癌(PTC)中的临床价值。方法回顾性选取2022年6月至2024年11月在北京市房山区良乡医院经病理证实的35例非弥漫型PTL和80例PTC的临床及超声... 目的探讨临床-超声多因素Logistic回归模型在鉴别非弥漫型原发性甲状腺淋巴瘤(PTL)与甲状腺乳头状癌(PTC)中的临床价值。方法回顾性选取2022年6月至2024年11月在北京市房山区良乡医院经病理证实的35例非弥漫型PTL和80例PTC的临床及超声影像学资料。分析非弥漫型PTL与PTC患者的临床资料(年龄、病灶长径、性别、甲状腺不对称增大及合并桥本甲状腺炎的情况)和超声特征(病灶回声类型、线状高回声、回声均匀性、边缘、囊性变、钙化、垂直位生长、后方回声增强、血流分级及包膜侵犯)。建立多因素Logistic回归模型,绘制受试者操作特征(ROC)曲线分析临床-超声因素鉴别诊断非弥漫型PTL与PTC的临床价值。结果单因素分析显示,非弥漫型PTL患者年龄、病灶长径、甲状腺不对称增大发生率和桥本甲状腺炎发生率均高于PTC患者,差异均有统计学意义(P<0.05);二者性别构成比差异无统计学意义(P>0.05)。非弥漫型PTL在极低回声、线状高回声、后方回声增强、血流丰富方面占比均高于PTC,而在边缘不规则、钙化和包膜侵犯方面占比均低于PTC,差异均有统计学意义(P<0.05);而二者回声均匀性、囊性变和垂直位占比比较,差异均无统计学意义(P>0.05)。多因素Logistic回归分析结果显示,年龄、病灶后方回声增强、线状高回声及钙化是鉴别二者的独立因素(P<0.05)。建立的回归方程为Logistic(Y)=3.451-0.081X1+3.204X2+3.237X3-2.935X4(X1:年龄;X2:后方回声增强;X3:线状高回声;X4:钙化),RE_1 ROC曲线下面积为0.932,鉴别二者的敏感度、特异度和准确性分别是91.4%、81.2%和88.6%。结论年龄、病灶后方回声增强、线状高回声和钙化可作为鉴别诊断非弥漫型PTL与PTC的可靠指标。临床-超声多因素Logistic回归模型在鉴别非弥漫型PTL和PTC中有较好的诊断效能。 展开更多
关键词 甲状腺癌 乳头状 超声检查 logistIC模型 原发性甲状腺淋巴瘤 鉴别诊断
暂未订购
基于决策树与Logistic回归模型的肺癌患者希望水平影响因素判别分析
3
作者 吕娟 吉硕 +2 位作者 刘亚 孙雯 潘瑞丽 《基础医学与临床》 2026年第3期402-410,共9页
目的分析肺癌患者希望水平的影响因素,以便尽早预测和识别较低希望水平的肺癌患者,并为提高肺癌患者希望水平干预措施的制订提供参考依据。方法抽取2024年7月至2024年12月在北京协和医院就诊的266例肺癌患者作为研究对象,使用Herth希望... 目的分析肺癌患者希望水平的影响因素,以便尽早预测和识别较低希望水平的肺癌患者,并为提高肺癌患者希望水平干预措施的制订提供参考依据。方法抽取2024年7月至2024年12月在北京协和医院就诊的266例肺癌患者作为研究对象,使用Herth希望指数(HHI)对纳入患者展开希望水平的调查。比较不同特征肺癌患者希望水平情况,采用决策树(DT)模型与Logistic回归模型分析影响肺癌患者希望水平的影响因素。结果剔除9例作答了无效问卷的患者后,本研究共纳入患者共257例。Logistic回归模型结果显示,确诊天数(B=-0.001)、肺癌分型[腺癌(B=0.177)、鳞癌(B=1.949)、其他(B=1.458)]、文化程度[高中、中专或技校(B=-1.182)、大专(B=0.392)、本科及以上(B=1.040)]、免疫治疗(B=-0.682)、体力状态(PS)评分[1级(B=1.657)、2级(B=2.102)、3级(B=0.171)]、心理弹性总分(CD-RISC)(B=-0.060)这6项是肺癌患者中等希望水平发生的独立影响因素;决策树分析结果显示,心理弹性总分是影响肺癌患者希望水平的主要因素,其次是文化程度和确诊天数。两个模型的ROC曲线下面积(AUC)分别为0.853(0.806,0.900)、0.850(0.801,0.898),其差异无统计学意义(Z=0.144,P=0.885)。结论Logistic回归模型和决策树模型在预测肺癌患者的希望水平时均有一定的应用价值,建议在临床中将二者结合使用,以便更好提高肺癌患者的希望水平。 展开更多
关键词 希望水平 心理弹性 logistIC回归 决策树
暂未订购
一类调制耦合logistics模型的动力学行为
4
作者 李亚男 刘娜 余志恒 《数学进展》 北大核心 2025年第3期545-570,共26页
本文主要研究了一类调制耦合logistics模型的动力学行为.我们首先运用多项式完全判别系统理论处理相关高阶半代数系统,并给出了该模型在各个不动点处的拓扑分类及其局部稳定性.其次,利用中心流形定理,我们分别给出该模型在不同非双曲情... 本文主要研究了一类调制耦合logistics模型的动力学行为.我们首先运用多项式完全判别系统理论处理相关高阶半代数系统,并给出了该模型在各个不动点处的拓扑分类及其局部稳定性.其次,利用中心流形定理,我们分别给出该模型在不同非双曲情形下不动点附近发生跨临界和超临界倍周期分岔的参数条件.此外,我们还证明了该模型具有Marotto意义下的混沌.最后,借助Maple 2023和Matlab R2019a,我们对该模型的动力学行为进行数值模拟,以进一步验证前述理论结果的正确性. 展开更多
关键词 耦合logistics模型 多项式完全判别系统 分岔 Marotto混沌
原文传递
Analysis on the adjustment of transportation structure and the logistics transformation of railway freight 被引量:1
5
作者 Chaohe Rong Xingchan Li +1 位作者 Gaiping Zhang Xuecheng Wang 《Railway Sciences》 2025年第1期82-96,共15页
Purpose–This paper aims to provide a comprehensive analysis of the strategic adjustments in China’s transportation structure,with a particular focus on the pivotal role of railway freight and its integration into th... Purpose–This paper aims to provide a comprehensive analysis of the strategic adjustments in China’s transportation structure,with a particular focus on the pivotal role of railway freight and its integration into the modern logistics system.It seeks to address the need for a more nuanced understanding of the“road to rail”policy,emphasizing the importance of intermodal collaboration and service of fragmented market demands.Design/methodology/approach–The study employs a transport economics perspective to evaluate the achievements and shortcomings of China’s transportation structure optimization.It bases its assessment of the current state of railway freight logistics,multi-modal transportation and the broader implications for the transportation service market on data analysis.The methodology includes a review of existing policies,an examination of industry practices and a comparative analysis with global trends in railway logistics.Findings–The research underscores the importance of focusing on the development of non-bulk materials,noting the insufficiency in the development of China’s rail multi-modal transportation and highlighting the instructive value of successful cases in open-top container road-rail intermodal transportation.The study posits that the railway sector must enhance cooperation with other market entities,aligning with the lead enterprises in the logistics chain that are characterized by speed,high value and strong coordination capabilities,in order to better serve the transportation market.This approach moves away from a reliance on the railway’s own capabilities alone.Originality/value–This paper offers original insights into the transformation of railway freight in China,contributing to the body of knowledge on transportation economics and logistics.It provides valuable recommendations for policymakers and industry practitioners,emphasizing the strategic importance of railway logistics in the context of China’s economic development and intense competition in the supply chain.The value of the article lies in its comprehensive understanding of the complexities involved in the adjustment of transportation structures,providing direction for the market-oriented reform of China’s railway freight sector. 展开更多
关键词 Transportation structure optimization Railway freight logistics transformation Multi-modal transport
在线阅读 下载PDF
结合Logistic映射和直方图特征引导的非对称加密算法设计
6
作者 李豪杰 李梦 许晓曾 《重庆工商大学学报(自然科学版)》 2026年第1期39-46,共8页
目的针对传统图像加密算法运算量大、速度慢且需要设计大量密钥的问题,提出结合Logistic映射和直方图特征引导的非对称加密方案。方法在加密过程中提取直方图的峰值点和谷值点作为加密私钥,并利用Logistic映射生成两个混沌序列,分别指... 目的针对传统图像加密算法运算量大、速度慢且需要设计大量密钥的问题,提出结合Logistic映射和直方图特征引导的非对称加密方案。方法在加密过程中提取直方图的峰值点和谷值点作为加密私钥,并利用Logistic映射生成两个混沌序列,分别指导图像像素的灰度加密和置乱加密。灰度加密的同时进行了像素的向后扩散;置乱加密时,先根据尺寸密钥对图像进行分块处理,然后将每个块的内部像素进行水平或垂直平移。结果对多张灰度图像和彩色图像进行加密和解密测试,并从各种经典攻击角度验证方案的安全性,发现该方案对图像内容加密效果良好,并完整保留了图像的质量和视觉效果。此外,相比于其他对比算法,用该方案加密后的图像熵值更接近8。结论该方案通过引入非线性混沌运算,并利用图像自身信息作为密钥,在实现简易运算的同时,不仅增加了加密算法的复杂性,也使得私钥在加密过程就完成了自动设计,避免了人为设计私钥的过程,显著提高了加密效率。 展开更多
关键词 图像加密 混沌序列 logistIC映射 直方图特征
在线阅读 下载PDF
多因素Logistic回归模型联合ROC曲线预测重症感染患者美罗培南血药浓度不达标的风险
7
作者 李淼 黄兴振 《中国处方药》 2026年第2期65-70,共6页
目的构建重症感染患者美罗培南血药浓度不达标风险的预测模型,为临床重症感染患者美罗培南的初始给药方案提供用药参考。方法选取广西某三级甲等医院2021年1月至2024年12月收治的436例疑似或确诊为脓毒血症需使用美罗培南抗感染治疗,同... 目的构建重症感染患者美罗培南血药浓度不达标风险的预测模型,为临床重症感染患者美罗培南的初始给药方案提供用药参考。方法选取广西某三级甲等医院2021年1月至2024年12月收治的436例疑似或确诊为脓毒血症需使用美罗培南抗感染治疗,同时进行血药浓度监测的住院患者作为研究对象。根据美罗培南血药浓度检测结果将患者分为达标组和未达标组,分析两组患者一般资料及临床检验指标,将差异有统计学意义的指标纳入多因素Logistic回归模型分析影响美罗培南血药浓度的因素,并构建重症感染患者美罗培南血药浓度不达标风险的预测模型,采用受试者工作特征(ROC)曲线评价该模型的预测效能。结果高龄、高Cr、低ALB及合并使用利尿剂的重症感染患者即使按常规剂量使用美罗培南,也更易出现暴露不足,需考虑个体化增量或延长输注。年龄、Cr、ALB及合并利尿剂预测重症感染患者美罗培南血药浓度不达标风险的灵敏度分别为69.20%、89.70%、58.10%和76.10%,特异度分别为65.80%、69.90%、66.50%和42.30%,曲线下面积(AUC)分别为0.718、0.858、0.655和0.592,四者联合预测的灵敏度为80.30%,特异度为83.10%,AUC为0.900,合并使用利尿剂、年龄、Cr和ALB联合预测美罗培南血药浓度不达标风险的效能优于任一指标单独预测(P<0.05)。结论年龄、Cr、ALB、合并使用利尿剂联合预测重症感染患者美罗培南血药浓度不达标风险具有较好的效能。高龄、高Cr、低ALB及合并使用利尿剂使重症患者即使按常规剂量也更易出现暴露不足,需考虑个体化增量或延长输注。 展开更多
关键词 美罗培南 血药浓度 logistIC回归 ROC曲线
暂未订购
Is digital transformation boosting green innovation in logistics enterprises?Evidence from listed firms in China’s logistics industry
8
作者 Jun Li Xi Chen Liang Wan 《中国科学技术大学学报》 北大核心 2025年第1期18-30,17,I0001,共15页
In the era of green logistics,digital transformation has become an effective means for the logistics industry’s high-quality development.Using listed companies in China’s logistics industry from 2010 to 2021 as the ... In the era of green logistics,digital transformation has become an effective means for the logistics industry’s high-quality development.Using listed companies in China’s logistics industry from 2010 to 2021 as the research samples,this paper conducts an empirical test on the impact of the digital transformation of logistics enterprises on their green in-novation.Specifically,enterprise digital transformation indicators are constructed through the text analysis method,and the fixed-effects model is applied for analysis.The results indicate that the digital transformation of logistics enterprises has a significant promoting effect on their green innovation;the promoting effect of the digital transformation of logistics enterprises on green innovation is primarily achieved by easing corporate financing constraints and reducing corporate en-vironmental uncertainty;and the impact of digital transformation on green innovation is geographically heterogeneous. 展开更多
关键词 DIGITALIZATION logistics enterprises green innovation
在线阅读 下载PDF
IACO优化Logistic混沌序列在无线传感器网络布局中应用
9
作者 陈静 《技术与市场》 2026年第1期33-36,共4页
为了压缩通信成本并减少传感器个数,采用蚁群算法的优化路径。标准混沌序列算法存在分簇随机的问题,为此引入混沌算子,提出一种利用改进蚁群算法(IACO)对Logistic混沌序列方法进行改进,并成功应用于无线传感器网络布局中。研究结果表明... 为了压缩通信成本并减少传感器个数,采用蚁群算法的优化路径。标准混沌序列算法存在分簇随机的问题,为此引入混沌算子,提出一种利用改进蚁群算法(IACO)对Logistic混沌序列方法进行改进,并成功应用于无线传感器网络布局中。研究结果表明:随着迭代周期的增加,通信成本降低,可有效防止出现局部最佳的现象。相比贪心算法(Greedy)与IACO方法,改进蚁群算法-最长公共子序列算法(IACO-LCS)的通信成本显著降低,达到目标收益。该研究对提高无线传感器布局优化能力具有一定的理论指导意义。 展开更多
关键词 无线传感器 布局优化 改进蚁群算法 logistIC混沌序列 搜索速度
在线阅读 下载PDF
基于CT血管造影参数的LASSO-logistic回归模型对颅内小动脉瘤破裂风险的预测价值
10
作者 程箫 刘亚辉 冉雅菲 《实用医技杂志》 2026年第1期12-16,I0004,共6页
目的探讨计算机断层扫描血管造影(CTA)参数在评估颅内小动脉瘤破裂风险中的应用价值。方法回顾性分析2022年1月至2024年12月于郑州市第二人民医院确诊的92例颅内小动脉瘤患者资料,根据患者就诊时是否伴有急性蛛网膜下腔出血的临床表现... 目的探讨计算机断层扫描血管造影(CTA)参数在评估颅内小动脉瘤破裂风险中的应用价值。方法回顾性分析2022年1月至2024年12月于郑州市第二人民医院确诊的92例颅内小动脉瘤患者资料,根据患者就诊时是否伴有急性蛛网膜下腔出血的临床表现及影像学证据,分为破裂组(28例)和未破裂组(64例)。收集患者基线资料及CTA参数,采用最小绝对收缩和选择算法(LASSO)回归筛选变量,logistic回归构建预测模型。结果单因素分析结果显示,破裂组患者在高血压病史(60.7%与37.5%;χ^(2)=4.249,P=0.039)、脑血管病家族史(21.4%与6.2%;χ^(2)=4.632,P=0.031)、血管分叉部动脉瘤(53.6%与31.2%;χ^(2)=4.117,P=0.042)、存在异常搏动点(39.3%与10.9%;χ^(2)=9.947,P=0.002)、后循环区动脉瘤(32.1%与14.1%;χ^(2)=4.046,P=0.044)、瘤高与载瘤动脉直径比(SR)值(1.71±0.29与1.52±0.30;t=2.823,P=0.006)、动脉瘤角度(67.82°±10.98°与62.78°±10.86°;t=2.041,P=0.044)及子囊存在(28.6%与10.9%;χ^(2)=4.439,P=0.035)等指标均显著高于未破裂组;破裂组受试者的瘤径比(AR)值(1.83±0.32与1.57±0.29;t=3.834,P<0.001)亦明显更高。经LASSO回归分析,筛选出9个具有预测价值的变量,包括高血压病史、脑血管病家族史、血管分叉部动脉瘤、存在异常搏动点、后循环区动脉瘤、AR值、SR值、动脉瘤角度、子囊存在。进一步logistic回归分析结果显示,后循环区动脉瘤[OR(95%CI)=2.740(1.187,6.328)]、AR值[OR(95%CI)=3.102(1.106,8.697)]、动脉瘤角度[OR(95%CI)=3.846(1.074,13.766)]及子囊存在[OR(95%CI)=3.865(1.105,13.524)]等因素与颅内小动脉破裂风险独立相关(均P<0.05)。结论颅内小动脉瘤破裂主要受后循环区动脉瘤、AR值、动脉瘤角度及子囊存在等因素的影响,LASSO-logistic回归可用于预测颅内小动脉瘤破裂风险。 展开更多
关键词 颅内动脉瘤 CT血管成像 最小绝对收缩和选择算法 logistIC回归
暂未订购
Effectiveness of Logistics Management Information System (LMIS) in Improving the Availability of Essential Medicines and Medical Supplies in Public Hospitals in Zambia: A Cross-Sectional Study
11
作者 Aubrey Kanyika Steward Mudenda +4 位作者 Victor Daka Nayuda Kaonga Chitundu Mbao Diana K. Mwaba Scott Kaba Matafwali 《Pharmacology & Pharmacy》 2025年第2期61-72,共12页
Background: The availability of essential medicines and medical supplies is crucial for effectively delivering healthcare services. In Zambia, the Logistics Management Information System (LMIS) is a key tool for manag... Background: The availability of essential medicines and medical supplies is crucial for effectively delivering healthcare services. In Zambia, the Logistics Management Information System (LMIS) is a key tool for managing the supply chain of these commodities. This study aimed to evaluate the effectiveness of LMIS in ensuring the availability of essential medicines and medical supplies in public hospitals in the Copperbelt Province of Zambia. Materials and Methods: From February to April 2022, a cross-sectional study was conducted in 12 public hospitals across the Copperbelt Province. Data were collected using structured questionnaires, checklists, and stock control cards. The study assessed LMIS availability, training, and knowledge among pharmacy personnel, as well as data accuracy, product availability, and order fill rates. Descriptive statistics were used to analyse the data. Results: All surveyed hospitals had LMIS implemented and were using eLMIS as the primary LMIS. Only 47% and 48% of pharmacy personnel received training in eLMIS and Essential Medicines Logistics Improvement Program (EMLIP), respectively. Most personnel demonstrated good knowledge of LMIS, with 77.7% able to log in to eLMIS Facility Edition, 76.6% able to locate stock control cards in the system, and 78.7% able to perform transactions. However, data accuracy from physical and electronic records varied from 0% to 60%, and product availability ranged from 50% to 80%. Order fill rates from Zambia Medicines and Medical Supplies Agency (ZAMMSA) were consistently below 30%. Discrepancies were observed between physical stock counts and eLMIS records. Conclusion: This study found that most hospitals in the Copperbelt Province of Zambia have implemented LMIS use. While LMIS implementation is high in the Copperbelt Province of Zambia, challenges such as low training levels, data inaccuracies, low product availability, and order fill rates persist. Addressing these issues requires a comprehensive approach, including capacity building, data quality improvement, supply chain coordination, and investment in infrastructure and human resources. Strengthening LMIS effectiveness is crucial for improving healthcare delivery and patient outcomes in Zambia. 展开更多
关键词 logistics Management Information System Essential Medicines Medical Supplies Supply Chain Management Zambia
在线阅读 下载PDF
具有Logistic增长和年龄结构的SEIQR传染病模型
12
作者 史旭元 高红亮 《华中师范大学学报(自然科学版)》 北大核心 2026年第1期18-26,共9页
本文建立了具有Logistic增长和年龄结构的SEIQR传染病模型.首先,定义了基本再生数R_(0),并证明R_(0)是决定疾病灭绝或存在的阈值.当R_(0)<1时,E_(0)是全局渐近稳定的;当R_(0)>1时,E_(0)是不稳定的,疾病将持续存在.其次,通过考察... 本文建立了具有Logistic增长和年龄结构的SEIQR传染病模型.首先,定义了基本再生数R_(0),并证明R_(0)是决定疾病灭绝或存在的阈值.当R_(0)<1时,E_(0)是全局渐近稳定的;当R_(0)>1时,E_(0)是不稳定的,疾病将持续存在.其次,通过考察相应特征方程的根分布,研究了地方病平衡点E*的稳定性,证明了当R_(0)>1,τ=0时,系统的地方病平衡点E*是局部渐近稳定的.接着,当地方病平衡点E*不稳定时,证明了在其周围存在Hopf分支.最后,利用Matlab对传染病模型进行数值模拟,验证所获结论的有效性. 展开更多
关键词 logistIC增长 年龄结构 基本再生数 HOPF分支
在线阅读 下载PDF
Bridging Emissions to Solutions: Enhancing Environmental Preservation through Green Inbound and Outbound Logistics
13
作者 Apeksha Garg Sudha Vemaraju Marri Madhavi 《Journal of Environmental & Earth Sciences》 2025年第6期280-292,共13页
Logistics service providers significantly contribute to environmental degradation through improper waste disposal,hazardous packaging materials,excessive fuel consumption,and emissions.This study examines the impact o... Logistics service providers significantly contribute to environmental degradation through improper waste disposal,hazardous packaging materials,excessive fuel consumption,and emissions.This study examines the impact of green in-bound logistics and green outbound logistics on environmental,economic,and social performance of logistics companies using survey data from 221 Vietnamese logistics firms.Statistical analysis using Structural Equation Modeling revealed that green inbound logistics positively influences environmental and social performance while moderately affecting eco-nomic outcomes.In contrast,green outbound logistics demonstrates stronger effects on economic and environmental performance but exhibits limited impact on social dimensions.The measurement model showed strong reliability and validity(Cronbach's Alpha>0.70,robust Composite Reliability and Average Variance Extracted values),with excellent fit indices(Chi-Square/df=1.681,GFI=0.898,TLI=0.945,CFI=0.956,RMSEA=0.056).These findings highlight important distinctions between inbound and outbound green logistics impacts,offering valuable insights for an industry with currently low adoption rates of sustainable practices.The research demonstrates that implementing green logistics enhances both environmental preservation and business performance,providing compelling evidence for companies to accelerate their sustainability transition.By understanding these differential impacts,logistics firms can develop more tar-geted and effective sustainability strategies that optimize triple bottom line outcomes. 展开更多
关键词 Green logistics Environmental Performance Social Performance logistics Firms IGL OGL Carbon Emissions Energy Efficiency
在线阅读 下载PDF
Research the Safety Specialties for the Container Shipping Logistics Networks of China
14
作者 Di Cui 《Journal of Traffic and Transportation Engineering》 2025年第2期62-65,共4页
Structural properties of the ship container logistics network of China(SCLNC)are studied in the light of recent investigations of complex networks.SCLNC is composed of a set of routes and ports located along the sea o... Structural properties of the ship container logistics network of China(SCLNC)are studied in the light of recent investigations of complex networks.SCLNC is composed of a set of routes and ports located along the sea or river.Network properties including the degree distribution,degree correlations,clustering,shortest path length,centrality and betweenness are studied in different definition of network topology.It is found that geographical constraint plays an important role in the network topology of SCLNC.We also study the traffic flow of SCLNC based on the weighted network representation,and demonstrate the weight distribution can be described by power law or exponential function depending on the assumed definition of network topology.Other features related to SCLNC are also investigated. 展开更多
关键词 logistics networks ship container logistics networks the safety characters
在线阅读 下载PDF
Logistics Engineering Management in the Platform Supply Chain: An Overview from Logistics Service Strategy Selection Perspective
15
作者 Lin Chen Ting Dong +1 位作者 Xiang Li Xiaofeng Xu 《Engineering》 2025年第4期236-249,共14页
With the accelerated expansion of the platform economy,the supply chain has evolved into a new stage of the platform supply chain(PSC),which is deeply integrated with the platform economy.Logistics engineering managem... With the accelerated expansion of the platform economy,the supply chain has evolved into a new stage of the platform supply chain(PSC),which is deeply integrated with the platform economy.Logistics engineering management plays a crucial role in ensuring the efficient operation of PSCs and contributes to the construction of a global economic system.Given its importance to the efficiency of PSCs,the choice of logistics service strategy in logistics engineering management has attracted considerable scholarly attention.However,the current research is fragmented and lacks systematic analysis and synthesis.This paper provides a comprehensive overview of logistics engineering management in PSCs from the perspective of logistics service strategy selection from January 2005 to September 2024.To this end,we first review the research related to self-built logistics(SBL)and third-party logistics(3PL)in PSCs due to the complete independence of these two logistics service strategies.The results show that the following two topics are of great interest to researchers.One is the choice of the optimal logistics service strategy for the members of PSCs,while the other is the impact of factors related to logistics services on PSCs,including the channel selection,platform entry,sales model,and so forth.Next,we summarize the determinants influencing the choice between SBL and 3PL for the members of PSCs.The results indicate that the influencing factors are the service cost and service level,followed by the channel,brand,market potential,and competition.Then,on the basis of the themes of logistics service sharing(LSS),we review the research on LSS in PSCs,as LSS often emerges as an innovative model after a certain stage of development in SBL and 3PL.We find that LSS is regarded as an important complement to SBL and 3PL,with key research hotspots,including the channel,partner selection,and service competition.Service cost is a major factor influencing LSS,with competition,consumers'logistics preference,and market potential being secondary factors.Finally,this paper outlines several important and promising directions for future research.This paper has important management implications for building a modern logistics system and promoting the transformation of PSCs. 展开更多
关键词 logistics engineering management Platform supply chain logistics service strategy Bibliometric analysis Literature review
在线阅读 下载PDF
Ecological Dynamics of a Logistic Population Model with Impulsive Age-selective Harvesting
16
作者 DAI Xiangjun JIAO Jianjun 《应用数学》 北大核心 2026年第1期72-79,共8页
In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asy... In this paper,we establish and study a single-species logistic model with impulsive age-selective harvesting.First,we prove the ultimate boundedness of the solutions of the system.Then,we obtain conditions for the asymptotic stability of the trivial solution and the positive periodic solution.Finally,numerical simulations are presented to validate our results.Our results show that age-selective harvesting is more conducive to sustainable population survival than non-age-selective harvesting. 展开更多
关键词 The logistic population model Selective harvesting Asymptotic stability EXTINCTION
在线阅读 下载PDF
基于logistic回归、决策树和神经网络构建成人慢性肾脏病合并活动性结核病的风险预测模型与应用
17
作者 陈德盼 李翔 +5 位作者 张开义 李敏 夏加伟 高楚伊 杨亚涛 张乐 《中国防痨杂志》 北大核心 2026年第1期94-105,共12页
目的:探究logistic回归模型、决策树模型和神经网络模型在预测慢性肾脏病(chronic kidney disease,CKD)患者合并活动性结核病中的应用价值。方法:回顾性分析2021年1月至2024年1月昆明市第三人民医院收治的CKD患者392例,其中合并活动性... 目的:探究logistic回归模型、决策树模型和神经网络模型在预测慢性肾脏病(chronic kidney disease,CKD)患者合并活动性结核病中的应用价值。方法:回顾性分析2021年1月至2024年1月昆明市第三人民医院收治的CKD患者392例,其中合并活动性结核病患者266例,为观察组,未合并活动性结核病患者126例,为对照组。收集两组患者的临床资料及实验室指标,采用logistic回归、决策树和神经网络三种模型筛选影响因素并构建风险预测模型,通过受试者工作特征(receiver operating characteristic,ROC)曲线比较模型的预测效能。结果:logistic回归模型的ROC曲线下面积(AUC)为0.726(95%CI:0.676~0.777),敏感度为45.1%,特异度为92.1%,同时识别出饮酒、咯血、低淋巴细胞计数、低红细胞压积、高尿酸、高纤维蛋白原降解产物和低白细胞介素10(IL-10)水平为独立预测因子(P值均<0.05)。决策树模型的AUC为0.825(95%CI:0.783~0.868),敏感度为62.0%,特异度为82.5%,该模型以纤维蛋白原降解产物为首要分层变量,进一步纳入CD4^(+)T淋巴细胞、淋巴细胞计数、红细胞压积、食欲不振和尿酸等变量构建决策路径。神经网络模型的预测效能最优,其AUC为0.876(95%CI:0.843~0.909),敏感度为60.9%,特异度高达98.4%,其特征重要性分析显示,IL-10、红细胞压积、纤维蛋白原降解产物和CD4^(+)T淋巴细胞为排名前4的预测因子。结论:神经网络模型对CKD患者合并活动性结核病的预测能力最佳。本研究识别出的关键预测因子,如低淋巴细胞计数、低CD4^(+)T淋巴细胞计数、高纤维蛋白原降解产物等有助于界定筛查重点人群。三种模型优势互补,可协同应用于临床:对于存在免疫功能抑制(如淋巴细胞、CD4^(+)T淋巴细胞计数低下)、凝血纤溶激活(如纤维蛋白原降解产物升高)及咯血等特征的CKD患者,应加强结核病筛查。 展开更多
关键词 结核 肾脏病学 logistIC模型 决策树 神经网络(计算机) 预测
暂未订购
妇科恶性肿瘤患者全麻术后感染的高危因素Logistic回归分析与预防措施
18
作者 吕文静 张兴月 +1 位作者 张华山 刘朝栋 《中国病原生物学杂志》 北大核心 2026年第4期492-495,502,共5页
目的运用Logistic回归分析妇科恶性肿瘤患者全麻术后感染的高危因素,为制定和优化预防措施提供参考。方法回顾性分析2021年1月~2025年6月在本院行全麻手术的342例妇科恶性肿瘤患者的临床资料,统计其全麻术后感染率,分析其感染部位和病... 目的运用Logistic回归分析妇科恶性肿瘤患者全麻术后感染的高危因素,为制定和优化预防措施提供参考。方法回顾性分析2021年1月~2025年6月在本院行全麻手术的342例妇科恶性肿瘤患者的临床资料,统计其全麻术后感染率,分析其感染部位和病原菌分布情况,以及用Logistic回归分析筛选妇科恶性肿瘤患者全麻术后感染的高危因素。结果342例妇科恶性肿瘤患者中,共51例发生全麻术后感染,感染率14.91%。妇科恶性肿瘤患者全麻术后感染部位依次为手术部位(21例,41.18%)、泌尿系统(16例,31.37%)、呼吸系统(10例,19.61%)、血流感染(4例,7.84%)。51例妇科恶性肿瘤全麻术后感染患者,共检出病原菌57株。其中,革兰阴性菌34株(构成比59.65%)、革兰阳性菌19株(构成比33.33%)、真菌4株(构成比7.02%)。合并糖尿病(OR=2.753,P<0.01)、术中低体温(OR=4.152,P<0.01)、术前贫血(OR=1.951,P<0.01)、麻醉时间≥3.5h(OR=4.006,P<0.01)、留置尿管时间≥5d(OR=3.654,P=0.000)和妇科恶性肿瘤患者全麻术后感染有关。感染组术后并发症发生率较未感染组低(P<0.05)。结论妇科恶性肿瘤患者全麻术后感染率14.91%,感染部位以手术部位多见,常见病原菌为革兰阴性菌,其发生和合并糖尿病、术中低体温、术前贫血、麻醉时间≥3.5h、留置尿管时间≥5d有关。术后感染会增加并发症。 展开更多
关键词 妇科 恶性肿瘤 全麻 术后感染 高危因素 logistic回归分析 预防措施
原文传递
Decoding the future:a bibliometric exploration of blockchain in logistics
19
作者 Ma Del Valle Fernandez Moreno Juan Miguel Alcantara‑Pilar Marta Tolentino 《Financial Innovation》 2025年第1期1134-1157,共24页
This paper presents the results of a bibliometric analysis concerning the application of blockchain technology to logistics.It aims to discern the relational structure among past and current topics,predict emerging tr... This paper presents the results of a bibliometric analysis concerning the application of blockchain technology to logistics.It aims to discern the relational structure among past and current topics,predict emerging trends,and provide a longitudinal perspective on this research domain.Using co-word analysis techniques,we employ SciMAT software to analyze over 800 papers from 2016 to March 2023.The investigation enhances the understanding of blockchain technology,revealing that scientific production in this area revolves around eight primary thematic clusters.Visual representations of the results are provided through longitudinal maps and strategic diagrams,illustrating pivotal themes across the three study periods:blockchain and sustainability.Smart contracts emerge as a focal topic in the final period under consideration. 展开更多
关键词 Bibliometric analysis SciMAT Blockchain technology logistIC
在线阅读 下载PDF
Research on the Path of Integration between Logistics and Manufacturing in Haikou Driven by Big Data
20
作者 Taoyuan Wan 《Proceedings of Business and Economic Studies》 2025年第2期160-165,共6页
With the constant changes of the times,China's science and technology have entered a period of rapid development.At the same time,the economic structure is also changing with the changes of the times,and the origi... With the constant changes of the times,China's science and technology have entered a period of rapid development.At the same time,the economic structure is also changing with the changes of the times,and the original Haikou logistics industry in the process is also facing new impacts and challenges.And related enterprises want to stand out in the fierce market competition,we must optimize and upgrade the current industry development situation,promote the integrated development of Haikou logistics and manufacturing industry,to constantly promote the innovative application of digital technology in the logistics industry and manufacturing industry,the formation of a multi-force economic development model.This paper mainly starts with the development status of Haikou logistics,analyzes the importance of the integration of Haikou logistics and manufacturing industry under the background of big data drive,and makes an in-depth discussion on the path of the integration of Haikou logistics and manufacturing industry under the drive of big data,hoping to contribute new strength to the development of social economy. 展开更多
关键词 Big data Haikou logistics Manufacturing industry CONVERGENCE PATHS
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部