期刊文献+
共找到4,445篇文章
< 1 2 223 >
每页显示 20 50 100
An Evaluation of the Critical Success Factors in Sustainable Food Supply Chains in Developing Countries
1
作者 Muhammad Ahasan Habib Deen Islam Preyo +1 位作者 Muhammad Kamruzzaman Ahasan Md. Maruf Hossain 《World Journal of Engineering and Technology》 2024年第3期466-492,共27页
Food is one of the biggest industries in developed and underdeveloped countries. Supply chain sustainability is essential in established and emerging economies because of the rising acceptance of cost-based outsourcin... Food is one of the biggest industries in developed and underdeveloped countries. Supply chain sustainability is essential in established and emerging economies because of the rising acceptance of cost-based outsourcing and the growing technological, social, and environmental concerns. The food business faces serious sustainability and growth challenges in developing countries. A comprehensive analysis of the critical success factors (CSFs) influencing the performance outcome and the sustainable supply chain management (SSCM) process. A theoretical framework is established to explain how they are used to examine the organizational aspect of the food supply chain life cycle analysis. This study examined the CSFs and revealed the relationships between them using a methodology that included a review of literature, interpretative structural modeling (ISM), and cross-impact matrix multiplication applied in classification (MICMAC) tool analysis of soil liquefaction factors. The findings of this research demonstrate that the quality and safety of food are important factors and have a direct effect on other factors. To make sustainable food supply chain management more adequate, legislators, managers, and experts need to pay attention to this factor. In this work. It also shows that companies aiming to create a sustainable business model must make sustainability a fundamental tenet of their organization. Practitioners and managers may devise effective long-term plans for establishing a sustainable food supply chain utilizing the recommended methodology. 展开更多
关键词 Supply Chain Collaboration Interpretative Structural Modeling Cross-Impact Matrix multiplication SUSTAINABILITY Critical Success factors multi-Criteria Decision Making Technique for Order of Preference by Similarity to Idea Solution
下载PDF
Dividing the Expropriated Areas Based on Multi-Factor Comprehensive Evaluation—A Case Study of Gongcheng Yao Autonomous County
2
作者 Yuening Song Xiangwen Cai +3 位作者 Mi Tang Mingyuan Liu Yan Zhao Zehao Liu 《Journal of Geographic Information System》 2020年第6期579-596,共18页
In recent years, with the rapid development of urbanization in China, land acquisition work is particularly important. The division of expropriated area is the primary factor to be considered when evaluating the compr... In recent years, with the rapid development of urbanization in China, land acquisition work is particularly important. The division of expropriated area is the primary factor to be considered when evaluating the comprehensive land price of expropriated area. Reasonable division can help to improve the scientific and applicability of the comprehensive land price of the region. How to maximize the protection of farmers’ rights and interests by the division of land requisition is an urgent problem to be solved. Taking Gongcheng Yao Autonomous County as an example, this study adopted the multi-factor comprehensive evaluation method to evaluate the division of land requisition in this area, and carried out the corresponding spatial analysis and data processing based on GIS technology. Gongcheng Yao Autonomous County was divided into levy areas, and the Delphi method was used to screen the impact factors and determine the weight of the levy areas. Reasonable division of land requisition area can provide references for land requisition area, make it more scientific and reasonable, and protect the rights and interests of farmers. 展开更多
关键词 Area Division multi factor Comprehensive Evaluation ARCGIS DELPHI
下载PDF
Multi-factor analysis of initial poor graft function after orthotopic liver transplantation 被引量:12
3
作者 Chen, Hao Peng, Cheng-Hong +5 位作者 Shen, Bai-Yong Deng, Xia-Xing Shen, Chuan Xie, Jun-Jie Dong, Wei Li, Hong-Wei 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2007年第2期141-146,共6页
BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study s... BACKGROUND: In the early period of orthotopic liver transplantation (OLT), initial poor graft function (IPGF) is one of the complications which leads to primary graft non-function (PGNF) in serious cases. This study set out to establish the clinical risk factors resulting in IPGF after OLT. METHODS: Eighty cases of OLT were analyzed. The IPGF group consisted of patients with alanine aminotransferase (ALT) and/or aspartate aminotransferase (AST) above 1500 IU/L within 72 hours after OLT, while those in the non-IPGF group had values below 1500 IU/L. Recipient-associated factors before OLT analyzed were age, sex, primary liver disease and Child-Pugh classification; factors analyzed within the peri-operative period were non-heart beating time (NHBT), cold ischemia time (CIT), rewarming ischemic time (RWIT), liver biopsy at the end of cold ischemia; and factors analyzed within 72 hours after OLT were ALT and/or AST values. A logistic regression model was applied to filter the possible factors resulting in IPGF. RESULTS: Donor NHBT, CIT and RWIT were significantly longer in the IPGF group than in the non-IPGF group; in the logistic regression model, NHBT was the risk factor leading to IPGF (P < 0.05), while CIT and RWIT were possible risk factors. In one case in the IPGF group, PGNF appeared with moderate hepatic steatosis. CONCLUSIONS: Longer NHBT is an important risk factor leading to IPGF, while serious steatosis in the donor liver, CIT and RWIT are potential risk factors. 展开更多
关键词 orthotopic liver transplantation poor liver function multi-factor analysis
下载PDF
The multi-factor recombination and processes superimposition model for hydrocarbon accumulation:application to the Silurian in the Tarim Basin 被引量:9
4
作者 Meng Qingyang Pang Xiongqi Gao Jianbo 《Petroleum Science》 SCIE CAS CSCD 2008年第1期13-19,共7页
The multi-factor recombination and processes superimposition model for hydrocarbon accumulation is put forward in view of the hydrocarbon geological characteristics of multiple episodes of structural evolution, multip... The multi-factor recombination and processes superimposition model for hydrocarbon accumulation is put forward in view of the hydrocarbon geological characteristics of multiple episodes of structural evolution, multiple sets of source-reservoir-seal assemblage, multiple cycles of hydrocarbon accumulation and multiple episodes of readjustment and reconstruction in the complex superimposed basins in China. It is a system including theories and methods that can help to predict favorable exploration regions. According to this model, the basic discipline for hydrocarbon generation, evolution and distribution in the superimposed basins can be summarized in multi-factor recombination, processes superimposition, multiple stages of oil filling and latest stage preservation. With the Silurian of the Tarim basin as an example, based on the reconstruction of the evolution history of the four factors (paleo-anticline, source rock, regional cap rock and kinematic equilibrium belt) controlling hydrocarbon accumulation, this model was adopted to predict favorable hydrocarbon accumulation areas and favorable exploration regions following structural destruction in three stages of oil filling, to provide guidance for further exploration ofoil and gas in the Silurian of the Tarim basin. 展开更多
关键词 multi-factor recombination processes superimposition Tarim Basin SILURIAN favorable exploration region prediction
下载PDF
Cellular Automata-based Chloride Ion Diffusion Simulation of Concrete Bridges under Multi-factor Coupling Actions 被引量:2
5
作者 ZHU Jinsong HE Likun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第1期160-165,共6页
In order to accurately simulate the diffusion of chloride ion in the existing concrete bridge and acquire the precise chloride ion concentration at given time, a cellular automata (CA)-based model is proposed. The p... In order to accurately simulate the diffusion of chloride ion in the existing concrete bridge and acquire the precise chloride ion concentration at given time, a cellular automata (CA)-based model is proposed. The process of chloride ion diffusion is analyzed by the CA-based method and a nonlinear solution of the Fick's second law is obtained. Considering the impact of various factors such as stress states, temporal and spatial variability of diffusion parameters and water-cement ratio on the process of chloride ion diffusion, the model of chloride ion diffusion under multi-factor coupling actions is presented. A chloride ion penetrating experiment reported in the literature is used to prove the effectiveness and reasonability of the present method, and a T-type beam is taken as an illustrative example to analyze the process of chloride ion diffusion in practical application. The results indicate that CA-based method can simulate the diffusion of chloride ion in the concrete structures with acceptable precision. 展开更多
关键词 concrete bridge chloride ion diffusion cellular automata multi-factor coupling actions
下载PDF
Investment in deepwater oil and gas exploration projects:a multi-factor analysis with a real options model 被引量:5
6
作者 Xin-Hua Qiu Zhen Wang Qing Xue 《Petroleum Science》 SCIE CAS CSCD 2015年第3期525-533,共9页
Deepwater oil and gas projects embody high risks from geology and engineering aspects, which exert substantial influence on project valuation. But the uncer- tainties may be converted to additional value to the projec... Deepwater oil and gas projects embody high risks from geology and engineering aspects, which exert substantial influence on project valuation. But the uncer- tainties may be converted to additional value to the projects in the case of flexible management. Given the flexibility of project management, this paper extends the classical real options model to a multi-factor model which contains oil price, geology, and engineering uncertainties. It then gives an application example of the new model to evaluate deepwater oil and gas projects with a numerical analytical method. Compared with other methods and models, this multi-factor real options model contains more project information. It reflects the potential value deriving not only from oil price variation but also from geology and engi- neering uncertainties, which provides more accurate and reliable valuation information for decision makers. 展开更多
关键词 Investment decision - Real options multi-factor model Option pricing - Deepwater oil and gas
下载PDF
Multi-factor sensitivity analysis of shallow unsaturated clay slope stability 被引量:1
7
作者 ZhuoyingTan MeifengCai 《Journal of University of Science and Technology Beijing》 CSCD 2005年第3期193-202,共10页
An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was... An unsaturated clay slope, with various sloping angles and a thickness of 14 m, consists of backfill, slope soil and residual soil. Slide interfaces were determined by geophysical approaches and the original slope was reconstructed. Sub-slope masses were classified based on the varieties of sloping angle. A force recursive principle was proposed to calculate the stability coefficient of the sub-slope masses. The influencing factors such as sloping angle, water content, hydrostatic pressure, seismic force as well as train load were analyzed. The range and correlation of the above-mentioned factors were discussed and coupled wave equations were established to reflect the relationships between unit weight, cohesion, internal frictional angle, and water content, as well as between internal frictional angle and cohesion. The sensitivity analysis of slope stability was carried out and susceptive factors were determined when the factors were taken as independent and dependent variables respectively. The results show that sloping angle, water content and earthquake are the principal susceptive factors influencing slope stability. The impact of hydrostatic pressure on slope stability is similar to the seismic force in quantity. Train load plays a small role in slope stability and its influencing only reaches the roadbed and its neighboring slope segment. If the factors are taken as independent variables, the influencing extent of water content and cohesion on slope stability can be weakened and train load can be magnified. 展开更多
关键词 unsaturated clay slope stability multi-factor sensitivity analysis
下载PDF
A branch-and-bound algorithm for discrete multi-factor portfolio optimization model 被引量:1
8
作者 牛淑芬 王国欣 孙小玲 《Journal of Shanghai University(English Edition)》 CAS 2008年第1期26-30,共5页
In this paper, a new branch-and-bound algorithm based on the Lagrangian dual relaxation and continuous relaxation is proposed for discrete multi-factor portfolio selection model with roundlot restriction in financial ... In this paper, a new branch-and-bound algorithm based on the Lagrangian dual relaxation and continuous relaxation is proposed for discrete multi-factor portfolio selection model with roundlot restriction in financial optimization. This discrete portfolio model is of integer quadratic programming problems. The separable structure of the model is investigated by using Lagrangian relaxation and dual search. Computational results show that the algorithm is capable of solving real-world portfolio problems with data from US stock market and randomly generated test problems with up to 120 securities. 展开更多
关键词 portfolio optimization discrete multi-factor model Lagrangian relaxation and continuous relaxation branch-and-bound method.
下载PDF
Multi-factor high-order intuitionistic fuzzy timeseries forecasting model 被引量:1
9
作者 Ya'nan Wang Yingjie Lei +1 位作者 Yang Lei Xiaoshi Fan 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第5期1054-1062,共9页
Fuzzy sets theory cannot describe the neutrality degreeof data, which has largely limited the objectivity of fuzzy time seriesin uncertain data forecasting. With this regard, a multi-factor highorderintuitionistic fuz... Fuzzy sets theory cannot describe the neutrality degreeof data, which has largely limited the objectivity of fuzzy time seriesin uncertain data forecasting. With this regard, a multi-factor highorderintuitionistic fuzzy time series forecasting model is built. Inthe new model, a fuzzy clustering algorithm is used to get unequalintervals, and a more objective technique for ascertaining membershipand non-membership functions of the intuitionistic fuzzy setis proposed. On these bases, forecast rules based on multidimensionalintuitionistic fuzzy modus ponens inference are established.Finally, contrast experiments on the daily mean temperature ofBeijing are carried out, which show that the novel model has aclear advantage of improving the forecast accuracy. 展开更多
关键词 multi-factor high-order intuitionistic fuzzy time series forecasting model intuitionistic fuzzy inference.
下载PDF
The prevalence of azoospermia factor microdeletion on the Y chromosome of Chinese infertile men detected by multi-analyte suspension array technology 被引量:18
10
作者 Yi-Jian Zhu Si-Yao Liu Huan Wang Ping Wei Xian-Ping Ding 《Asian Journal of Andrology》 SCIE CAS CSCD 2008年第6期873-881,共9页
Aim: To develop a high-throughput multiplex, fast and simple assay to scan azoospermia factor (AZF) region microdeletions on the Y chromosome and establish the prevalence of Y chromosomal microdeletions in Chinese ... Aim: To develop a high-throughput multiplex, fast and simple assay to scan azoospermia factor (AZF) region microdeletions on the Y chromosome and establish the prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. Methods: In total, 178 infertile patients with azoospermia (nonobstructed), 134 infertile patients with oligozoospermia as well as 40 fertile man controls were included in the present study. The samples were screened for AZF microdeletion using optimized multi-analyte suspension array (MASA) technology. Results: Of the 312 patients, 36 (11.5%) were found to have deletions in the AZF region. The rnicrodeletion frequency was 14% (25/178) in the azoospermia group and 8.2% (11/134) in the oligospermia group. Among 36 patients with microdeletions, 19 had deletions in the AZFc region, seven had deletions in AZFa and six had deletions in AZFb. In addition, four patients had both AZFb and AZFc deletions. No deletion in the AZF region was found in the 40 fertile controls. Conclusion: There is a high prevalence of Y chromosomal microdeletions in Chinese infertile males with azoospermia or oligozoospermia. The MASA technology, which has been established in the present study, provides a sensitive and high-throughput method for detecting the deletion of the Y chromosome. And the results suggest that genetic screening should be advised to infertile men before starting assisted reproductive treatments. 展开更多
关键词 Y chromosome microdeletion azoospermia factor male infertility multi-analyte suspension array (MASA)
下载PDF
Enhancing Multi-Factor Authentication in Modern Computing
11
作者 Ekwonwune Emmanuel Nwabueze Iwuoha Obioha Oju Onuoha 《Communications and Network》 2017年第3期172-178,共7页
Most network service providers like MTN Nigeria, currently use two-factor authentication for their 4G wireless networks. This exposes the network subscribers to identify theft and users data to security threats like s... Most network service providers like MTN Nigeria, currently use two-factor authentication for their 4G wireless networks. This exposes the network subscribers to identify theft and users data to security threats like snooping, sniffing, spoofing and phishing. There is need to curb these problems with the use of an enhanced multi-factor authentication approach. The objective of this work is to create a multi-factor authentication software for a 4G wireless network. Multi-factor authentication involves user’s knowledge factor, user’s possession factor and user’s inherence factor;that is who the user is to be presented before system access can be granted. The research methodologies used for this work include Structured System Analysis and Design Methodology, SSADM and Prototyping. The result of this work will be a Multi-factor authentications software. This software was designed with programming languages like ASP. NET, C# and Microsoft SQL Server for the database. 展开更多
关键词 Enhanced multi-factor AUTHENTICATION Rapid PROTOTYPING Security THREAT Encryption HACKERS PHISHING MALWARE Tokens
下载PDF
Multi-factor Analysis Model for Improving Profit Management Using Excel in Shellfish Farming Projects
12
作者 Zhuming ZHAO Changlin LIU +1 位作者 Xiujuan SHAN Jin YU 《Asian Agricultural Research》 2013年第11期21-23,共3页
By using a farm's data in Yantai City and the theory of Cost-Volume-Profit analysis and the financial management methods,this paper construct a multi-factor analysis model for improving profit management using Exc... By using a farm's data in Yantai City and the theory of Cost-Volume-Profit analysis and the financial management methods,this paper construct a multi-factor analysis model for improving profit management using Excel 2007 in Shellfish farming projects and describes the procedures to construct a multi-factor analysis model.The model can quickly calculate the profit,improve the level of profit management,find out the breakeven point and enhance the decision-making efficiency of businesses etc.It is also a thought of the application to offer suggestions for government decisions and economic decisions for corporations as a simple analysis tool.While effort has been exerted to construct a four-variable model,some equally important variables may not be discussed sufficiently due to limitation of the paper's space and the authors'knowledge.All variables can be listed in EXCEL 2007 and can be associated in a logical way to manage the profit of shellfish farming projects more efficiently and more practically. 展开更多
关键词 SHELLFISH FARMING Cost-Volume-Profit analysis MULT
下载PDF
Effect of Multi-parameter Environmental Factors on Cucumber Leaf Surface Wetness
13
作者 Chunyang QIAN Jianchun WANG +2 位作者 Fengju LI Zhiwen SONG Yan WANG 《Agricultural Biotechnology》 CAS 2019年第2期32-34,共3页
In this study, artificial leaf resistance was used to simulate leaf wetness. Specific to the solar greenhouse environment in Tianjin, microclimate monitoring equipment was installed for the collection of temperature g... In this study, artificial leaf resistance was used to simulate leaf wetness. Specific to the solar greenhouse environment in Tianjin, microclimate monitoring equipment was installed for the collection of temperature group and humidity group data, as well as solar radiation and leaf wetness in the greenhouse. In order to reduce the complexity of multivariate factor prediction and ensure the richness of selected data types, correlation analysis was made to the 2 groups of data, screening 5 000 groups of data, including the humidity group data RH, RH_(20), RH_(40), temperature group data T, T_(20), T_(40), and solar radiation W. The data were then analyzed by principal component analysis, screening out 4 groups of principal components to show the leaf wetness index. 展开更多
关键词 CUCUMBER LEAF wetness Principal COMPONENT analysis multi-PARAMETER factorS
下载PDF
水资源-能源-粮食-生态系统耦合协调及驱动力分析 被引量:2
14
作者 杨明明 朱永楠 +2 位作者 赵勇 杨文静 樊煜 《人民黄河》 CAS 北大核心 2024年第3期58-63,共6页
为加深对我国水资源、能源、粮食、生态系统协同演变趋势的认识,构建水资源-能源-粮食-生态多维系统指标体系,运用耦合协调度模型对我国2005—2020年水资源-能源-粮食-生态系统耦合协调度进行评价,并采用多因素归因分析法进行驱动力分... 为加深对我国水资源、能源、粮食、生态系统协同演变趋势的认识,构建水资源-能源-粮食-生态多维系统指标体系,运用耦合协调度模型对我国2005—2020年水资源-能源-粮食-生态系统耦合协调度进行评价,并采用多因素归因分析法进行驱动力分析。结果表明:我国水资源-能源-粮食-生态系统耦合协调度从2005年的0.55增长到2020年的0.84,各地区耦合协调度从勉强协调发展水平过渡到中级协调发展水平,各子系统对耦合协调度上升的驱动分别经历了由粮食子系统到生态子系统再到水资源子系统主导的过程;能源子系统的贡献率虽然比较小,但是未来可能是各地区提升水资源-能源-粮食-生态系统多维系统协调发展水平的突破口。 展开更多
关键词 水资源-能源-粮食-生态 耦合协调度 多因素归因分析 驱动力
下载PDF
Productivity Testing Design Method of Multi-Factor Control for Unconsolidated Sandstone Gas Reservoir
15
作者 Muwang Wu Hao Liang +2 位作者 Mingjie Zhang Dianqiang Sun Peng Zhong 《Engineering(科研)》 2016年第11期815-822,共8页
Reservoir safety, testing-string safety, and flow control are key factors that should be considered in deep-water unconsolidated sandstone gas well testing work system. Combined with the feature of testing reservoir, ... Reservoir safety, testing-string safety, and flow control are key factors that should be considered in deep-water unconsolidated sandstone gas well testing work system. Combined with the feature of testing reservoir, pipe string type and sea area, the required minimum testing flow rate during cleaning up process, as well as minimum test flow rate without hydrate generation, pipe string erosion critical production, the maximum testing flow rate without destroying sand formation and the minimum output of meeting the demand of development was analyzed;based on the above critical test flow rates, testing working system is designed. Field application showed that the designed work system effectively provided good guidance for field test operations;no sand production or hydrate generation happened during the test process;the test parameter evaluated the reservoir accurately;the safe and efficient test operation was achieved. 展开更多
关键词 multi-factor Control Productivity Testing Unconsolidated Sandstone Gas Well HYDRATE SANDING
下载PDF
智能家居网络下基于多因子的认证密钥协商方案
16
作者 张敏 冯永强 +1 位作者 许春香 张建华 《信息网络安全》 CSCD 北大核心 2024年第1期133-142,共10页
智能家居网络通过物联网技术将智能设备相连,用户可以远程查看和控制家居设备,但信息在不安全的公共网络上传输将面临各种网络威胁,因此研究和设计安全高效且符合智能家居网络的认证密钥协商协议非常必要。2020年,WAZID等人针对智能家... 智能家居网络通过物联网技术将智能设备相连,用户可以远程查看和控制家居设备,但信息在不安全的公共网络上传输将面临各种网络威胁,因此研究和设计安全高效且符合智能家居网络的认证密钥协商协议非常必要。2020年,WAZID等人针对智能家居网络提出轻量级认证密钥协商方案(Wazid-Das方案),经过安全性分析和证明后发现,该方案过于依赖智能家居网关节点(Gateway Node,GWN),系统健壮性不高;该方案将用户和设备密钥存储在GWN中,但GWN面临特权攻击和各种外部网络攻击,并不绝对安全,且没有考虑用户的访问控制。文章在Wazid-Das方案的基础上针对智能家居网络提出一种基于切比雪夫映射(Chebyshev Chaotic Map)和安全略图(Secure Sketch)的多因子认证密钥协商方案。安全性证明和仿真实验结果表明,该方案虽然计算开销有所增加,但安全性显著提高,且通信开销大幅降低。 展开更多
关键词 智能家居 安全略图 多因子认证 切比雪夫映射 密钥协商
下载PDF
多因素耦合下沥青混合料拉压差异力学特性
17
作者 潘勤学 姜舜君 +1 位作者 吕松涛 郑健龙 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第9期1341-1352,共12页
针对现行沥青路面设计时材料力学参数取值的可靠性不足,基于道路材料的拉压差异特性,开展了多因素耦合影响下沥青混合料拉压力学参数非线性特性及量化关系研究。结果表明,沥青混合料拉压应力应变特性符合双模量理论的双线性特征;拉压力... 针对现行沥青路面设计时材料力学参数取值的可靠性不足,基于道路材料的拉压差异特性,开展了多因素耦合影响下沥青混合料拉压力学参数非线性特性及量化关系研究。结果表明,沥青混合料拉压应力应变特性符合双模量理论的双线性特征;拉压力学参数随加载速度增大先急剧增加后趋于平缓,且呈幂函数关系;与温度呈负指数函数关系,且温度增幅越高力学参数减小幅度越大;与沥青用量呈指数衰减模型函数关系,高温时(>30℃)沥青用量的变化对力学参数影响相对较小,最大力学参数所对应的沥青用量与马歇尔试验得到的最佳沥青用量基本一致;就影响程度而言,温度对力学参数的影响最大,各因素对强度的影响最为显著,抗拉力学参数较抗压力学参数更为敏感;据此建立了多因素耦合作用下沥青混合料的拉压力学参数量化取值模型,并推荐规范常用温度15℃(20℃)下的压拉强度比及压拉模量比分别为6.5(7.5)、1.6(1.7),压缩模强比及拉伸模强比分别为400(1700)、450(2000)。 展开更多
关键词 道路工程 沥青混合料 多因素耦合 非线性 力学特性 量化模型
下载PDF
坡度、疲劳和能见度对隧道火灾人员疏散速度耦合影响研究
18
作者 姜学鹏 彭义 《中国安全生产科学技术》 CAS CSCD 北大核心 2024年第5期93-99,共7页
为探究隧道火灾复杂环境对人员疏散速度的耦合影响规律,首先对坡度、人体疲劳及能见度3种因素开展疏散试验,获得各单因素对疏散速度的影响规律,并拟合出疏散速度变化公式;其次基于各单因素下速度变化公式,提出多因素耦合影响下隧道火灾... 为探究隧道火灾复杂环境对人员疏散速度的耦合影响规律,首先对坡度、人体疲劳及能见度3种因素开展疏散试验,获得各单因素对疏散速度的影响规律,并拟合出疏散速度变化公式;其次基于各单因素下速度变化公式,提出多因素耦合影响下隧道火灾人员疏散速度计算方法。研究结果表明:人员上坡疏散速度与坡度线性负相关,下坡疏散速度规律性较弱;长距离疏散时因疲劳导致速度逐渐衰减,在2 km疏散过程中速度衰减峰值达47%,疲劳导致的速度衰减比例与疏散距离线性正相关;能见度较高时其对疏散速度的影响效果不显著,能见度降低至10 m内后开始对疏散速度产生负面作用。研究结果可为隧道疏散设施设计、相关标准规范制定等提供参考,同时为传统疏散速度取值方法提供1个新思路。 展开更多
关键词 疏散速度试验 坡度 人体疲劳 能见度 多因素耦合
下载PDF
老年患者麻醉手术中压力性损伤发生情况调查及其预测模型的建立
19
作者 宋慧敏 杨玉玲 +2 位作者 牟利 康妮 李林佶 《武警医学》 CAS 2024年第5期389-394,共6页
目的调查老年患者麻醉手术中压力性损伤的发生情况,建立预测风险的列线图模型并进行内部验证。方法回顾性分析2018-02至2020-08在南充市中心医院进行麻醉手术的老年患者327例。收集麻醉手术中可能发生压力性损伤的因素,根据有无压力性... 目的调查老年患者麻醉手术中压力性损伤的发生情况,建立预测风险的列线图模型并进行内部验证。方法回顾性分析2018-02至2020-08在南充市中心医院进行麻醉手术的老年患者327例。收集麻醉手术中可能发生压力性损伤的因素,根据有无压力性损伤分为两组,比较其差异,并采用多因素Logistic回归分析压力性损伤的影响因素,并建立列线图预测模型进行内部验证。结果327例都完成了皮肤情况的观察,观察期间共41例(12.53%)出现压力性损伤。通过LASSO回归模型筛选出9个潜在的影响因素,并行多因素Logisitc回归分析,结果显示,年龄、BMI、吸烟史、手术体位、术中变换体位、手术时间、术中低温、白蛋白水平是老年患者麻醉手术中发生压力性损伤的独立性影响因素(P<0.05)。ROC曲线显示模型预测老年患者麻醉手术中发生压力性损伤的AUC为0.926(95%CI:0.888~0.965);校准曲线和H-L拟合优度检验结果显示,该列线图模型预测的概率与实际概率差异无统计学意义(P>0.05)。结论老年患者麻醉手术中压力性损伤发生率较高,主要受年龄、BMI、吸烟史等因素影响,根据上述因素建立的列线图模型预测麻醉手术中压力性损伤具有较高的准确度与区分度。 展开更多
关键词 老年 术中 压力性损伤 多因素分析 列线图模型
下载PDF
妊娠期心脏疾病患者伴心力衰竭的多因素模型构建及妊娠结局分析
20
作者 张雅 刘晓红 王影 《广西医科大学学报》 CAS 2024年第1期111-116,共6页
目的:构建妊娠期心脏疾病患者伴心力衰竭的多因素模型,并分析合并心力衰竭对妊娠结局的影响。方法:收集2021年1月至2022年12月陕西省人民医院产科收治的148例妊娠期心脏疾病患者为研究对象,随访至孕妇分娩,统计心力衰竭发生状况,将其分... 目的:构建妊娠期心脏疾病患者伴心力衰竭的多因素模型,并分析合并心力衰竭对妊娠结局的影响。方法:收集2021年1月至2022年12月陕西省人民医院产科收治的148例妊娠期心脏疾病患者为研究对象,随访至孕妇分娩,统计心力衰竭发生状况,将其分为伴心力衰竭组(56例)与单纯心脏疾病组(92例)。对比两组临床资料,构建妊娠期心脏疾病患者伴心力衰竭的多因素logistic回归模型,探讨妊娠期心脏疾病患者发生心力衰竭的影响因素,并绘制受试者工作特征曲线(ROC)验证上述因素对患者发生心力衰竭的影响。结果:伴心力衰竭组妊娠期高血压、贫血、低蛋白血症、肺动脉高压发生率高于单纯心脏疾病组,脑钠肽(BNP)水平高于单纯心脏疾病组(P<0.05);Logistic回归模型结果显示,妊娠期高血压、贫血、低蛋白血症、肺动脉高压、高BNP水平是妊娠期心脏疾病患者发生心力衰竭的危险因素(OR=72.644、4.871、43.693、30.391、1.024,P<0.05)。ROC曲线结果显示,AUC=0.934,模型可靠、稳定。伴心力衰竭组剖宫产率、产后出血率高于单纯心脏疾病组,新生儿Apgar评分低于单纯心脏疾病组(P<0.05)。结论:妊娠期心脏疾病患者心力衰竭的发生可能与妊娠期高血压、贫血、低蛋白血症、肺动脉高压、高BNP水平有关,建立的logistic回归模型可预测妊娠期心脏疾病患者发生心力衰竭的可能性。 展开更多
关键词 妊娠期心脏疾病 心力衰竭 多因素模型构建 妊娠结局
下载PDF
上一页 1 2 223 下一页 到第
使用帮助 返回顶部