期刊文献+
共找到21,478篇文章
< 1 2 250 >
每页显示 20 50 100
Quantum Secure Undeniable Signature for Blockchain-Enabled Cold-Chain Logistics System
1
作者 Chaoyang Li Hongxue Shen +1 位作者 Xiayang Shi Hui Liang 《Computers, Materials & Continua》 SCIE EI 2023年第5期3941-3956,共16页
Data security and user privacy are two main security concerns in the cold-chain logistics system(CCLS).Many security issues exist in traditional CCLS,destroying data security and user privacy.The digital signature can... Data security and user privacy are two main security concerns in the cold-chain logistics system(CCLS).Many security issues exist in traditional CCLS,destroying data security and user privacy.The digital signature can provide data verification and identity authentication based on the mathematical difficulty problem for logistics data sharing in CCLS.This paper first established a blockchain-enabled cold-chain logistics system(BCCLS)based on union blockchain technology,which can provide secure data sharing among different logistics nodes and guarantee logistics data security with the untampered blockchain ledger.Meanwhile,a lattice-based undeniable signature scheme is designed to strengthen the security of logistics data and user privacy against quantum attacks.This scheme is based on the lattice assumption,which can provide anti-quantum security for BCCLS in the future quantum computer age.It also establishes the undeniable mechanism that guarantees that the actual signer cannot deny a valid signature.Then,security proof shows that this undeniable signature scheme is correct and safe,and an efficiency comparison shows that it is more efficient than other schemes in similar literature.The performance evaluations of transaction throughput and latency show that the proposed BCCLS is efficient and practical.This work can improve the security and efficiency of logistics data management and promote the reform and development of the logistics industry. 展开更多
关键词 Undeniable signature cold-chain logistics system blockchain PRIVACY-PRESERVING
下载PDF
Stackelberg Game-Based Resource Allocation with Blockchain for Cold-Chain Logistics System 被引量:1
2
作者 Yang Zhang Chaoyang Li Xiangjun Xin 《Computers, Materials & Continua》 SCIE EI 2023年第5期2429-2442,共14页
Cold-chain logistics system(CCLS)plays the role of collecting and managing the logistics data of frozen food.However,there always exist problems of information loss,data tampering,and privacy leakage in traditional ce... Cold-chain logistics system(CCLS)plays the role of collecting and managing the logistics data of frozen food.However,there always exist problems of information loss,data tampering,and privacy leakage in traditional centralized systems,which influence frozen food security and people’s health.The centralized management form impedes the development of the cold-chain logistics industry and weakens logistics data availability.This paper first introduces a distributed CCLS based on blockchain technology to solve the centralized management problem.This system aggregates the production base,storage,transport,detection,processing,and consumer to form a cold-chain logistics union.The blockchain ledger guarantees that the logistics data cannot be tampered with and establishes a traceability mechanism for food safety incidents.Meanwhile,to improve the value of logistics data,a Stackelberg game-based resource allocation model has been proposed between the logistics data resource provider and the consumer.The competition between resource price and volume balances the resource supplement and consumption.This model can help to achieve an optimal resource price when the Stackelberg game obtains Nash equilibrium.The two participants also can maximize their revenues with the optimal resource price and volume by utilizing the backward induction method.Then,the performance evaluations of transaction throughput and latency show that the proposed distributed CCLS is more secure and stable.The simulations about the variation trend of data price and amount,optimal benefits,and total benefits comparison of different forms show that the resource allocation model is more efficient and practical.Moreover,the blockchain-based CCLS and Stackelberg game-based resource allocation model also can promote the value of logistic data and improve social benefits. 展开更多
关键词 Cold-chain logistics resource allocation Stackelberg game blockchain
下载PDF
RIAMB:Advanced intelligent logistics system solutions provider
3
《China Textile》 2023年第3期85-85,共1页
The warehousing and logistics business of Beijing Research Institute of Automation for Machinery Industry Co., Ltd.(hereinafter referred to as Beijing Research Institute) originated in the 1970s, and has accumulated m... The warehousing and logistics business of Beijing Research Institute of Automation for Machinery Industry Co., Ltd.(hereinafter referred to as Beijing Research Institute) originated in the 1970s, and has accumulated more than 60 years of technology research experience in project implementation. As the first company engaged in R&D of automated logistics technology in China, Beijing Research Institute is at the forefront of the industry. 展开更多
关键词 originated logistics system
下载PDF
Rural Logistics System Based on Rural Informatization 被引量:2
4
作者 HU Cui-hong 《Asian Agricultural Research》 2010年第2期10-12,16,共4页
Current status of rural informatization construction in China,including the relatively weak rural informatization,asymmetric market information,low level of information sharing,dispersedly allocated resources and no c... Current status of rural informatization construction in China,including the relatively weak rural informatization,asymmetric market information,low level of information sharing,dispersedly allocated resources and no cross point among each other are analyzed.The importance of informatization in rural logistic system is introduced:firstly,decision making of logistics system plan is based on information.Secondly,improvement of the overall efficiency of logistics system is based on information.Thirdly,logistics transmission takes the Internet as the carrier.Necessity of rural logistics system is discussed from five aspects of increasing the employment of farmers,enhancing the income of farmers,reducing the blindness of agricultural production and circulation,sharing the risks of agricultural management,and promoting the rural economic restructuring.According to the above five steps,five countermeasures are posed in order to improve the rural logistics system.The countermeasures cover the aspects of deepening the information awareness of government,establishing a rural informatization system suited to the national condition of China,strengthening the information infrastructure in rural areas,promoting the integration of rural information resources and establishing the training system for agricultural information talents. 展开更多
关键词 Rural informatization logistics system Information system RESOURCE China
下载PDF
Modeling and Analysis of Logistics System Based on Stochastic Petri Net under Supply Chain Circumstances 被引量:2
5
作者 孙亮 王光臣 孙建镇 《Journal of Southwest Jiaotong University(English Edition)》 2009年第3期253-258,共6页
In order to describe the impacts of adjustment ability of logistics system on the profit and cost of logistics system, we constructed a model of logistics system based on stochastic Petri net ( SPN), and proposed a ... In order to describe the impacts of adjustment ability of logistics system on the profit and cost of logistics system, we constructed a model of logistics system based on stochastic Petri net ( SPN), and proposed a theorem for the adjustment ability of logistics system under supply chain circumstances on condition that the payoff of supply chain is a steadily increasing process. Then we put forward that a sequence of MGF ( moment generating function ) of out-of-goods risk process for logistics system is a martingale. The model we proposed can overcome shortcomings of the previous ones that can not describe the characteristics of the adjustment ability of logistics system. The results of simulation experiments are consistent with theoretical analysis. 展开更多
关键词 logistics engineering logistics system Stochastic Petri net
下载PDF
A Study on Establishing a Cross-border E-commerce Logistics System for Agricultural Products in Sichuan Province in the Context of the Belt and Road Initiative
6
作者 You Jing Chen Haonan 《Contemporary Social Sciences》 2021年第5期13-28,共16页
The rapid development of cross-border e-commerce,especially since Chengdu was listed as an Integrated Pilot Zone for Cross-Border E-Commerce in 2016,has led to a rising trade value of agricultural products in the metr... The rapid development of cross-border e-commerce,especially since Chengdu was listed as an Integrated Pilot Zone for Cross-Border E-Commerce in 2016,has led to a rising trade value of agricultural products in the metropolis.This upward trend is also attributed to the China-Europe Railway Express and the Chengdu International Aviation Hub Integrated Functional Area,two infrastructure systems that have opened more international logistics channels for agricultural products in Sichuan province.However,the development of cross-border logistics has failed to respond to the rapid growth of cross-border e-commerce for agricultural products.This problem has given rise to longer delivery cycles,higher costs,and reduced product quality,hindering the development of cross-border e-commerce for agricultural products.Currently,most research efforts are focused on selecting a logistics mode which has created an urgency is to establish a logistics system.To that end,we must utilize the opportunities and preferential policies brought about by the Belt and Road Initiative to advance the establishment of a cross-border logistics system for agricultural products,which will create more channels for selling Sichuan’s agricultural products overseas.This article analyzes the current situation of the cross-border logistics system for agricultural products produced by the province and studies the potential relationships between a logistics system and cross-border trade of agricultural products.It seeks to build a logistics system that meets the demands of cross-border transactions using economic theories focused on cross-border e-commerce and logistics.Such a logistic system will help shorten long delivery cycles,cut delivery costs,and guarantee the quality of agricultural products.Also,it can contribute to the rapid development of cross-border e-commerce of agricultural products and solve problems in developing the agricultural products logistics system of Sichuan province. 展开更多
关键词 the Belt and Road Initiative agricultural products cross-border e-commerce logistics system
下载PDF
The Study on the Framework and Implementation Scheme of the Railway Intelligent Cold Chain Logistics System
7
作者 Wei Xu Gang Li Xuefei Li 《Advances in Internet of Things》 2022年第3期110-123,共14页
With the development of intelligent and communication technology, traditional logistics has gradually transformed into intelligent logistics. The construction of the railway intelligent cold chain logistics system is ... With the development of intelligent and communication technology, traditional logistics has gradually transformed into intelligent logistics. The construction of the railway intelligent cold chain logistics system is an effective measure to implement the structural adjustment of supply, which conforms to the times. Firstly, basic features and design principles of the railway intelligent cold chain logistics system were described. Secondly, target functions and the system framework of the railway intelligent cold chain logistics were put forward, which takes information service as a foundation, management service as a guarantee, business capability as kernel and expansion capability as support. Subsequently, the technical approaches were studied at the hardware, processing and software levels. Finally, development strategies of the railway intelligent cold chain logistics were discussed, including optimizing the layout of infrastructure, improving the performance of equipment, extending the reach of services, deepening the cooperation of technologies and promoting the formulation of standards which provides feasible references for the railway cold chain logistics to explore modern business models. 展开更多
关键词 China Railway Cold Chain logistics Intelligent logistics system system Framework Scheme Design
下载PDF
Teaching Research and Practice of Logistics Management Major Based on OBE-CDIO-A Case Study of Logistics System Planning and Design Course
8
作者 Haiou Xiong 《Journal of Contemporary Educational Research》 2021年第10期99-103,共5页
The economic and social progress under the new era has put forward new requirements for logistics talents.Based on the teaching concept of OBE-CDIO as well as the training program and objectives of logistics managemen... The economic and social progress under the new era has put forward new requirements for logistics talents.Based on the teaching concept of OBE-CDIO as well as the training program and objectives of logistics management major in Guangzhou Maritime University,this study analyzes and discusses how the Logistics System Planning and Design course,which is targeted at students majoring in logistics management,enables the students to meet the graduation requirements by virtue of realizing the course objectives. 展开更多
关键词 OBE logistics management logistics system planning and design Teaching research
下载PDF
Empirical Study of E-logistics System Based on Tibet Logistics Industry 被引量:2
9
作者 Yu LIU 《Asian Agricultural Research》 2013年第8期5-9,共5页
With the rapid growth of E-logistics in the global logistics industry,it is important to get insight into E-logistics system in Chinese logistics industry.Regarding the current situation of E-logistics of Chinese logi... With the rapid growth of E-logistics in the global logistics industry,it is important to get insight into E-logistics system in Chinese logistics industry.Regarding the current situation of E-logistics of Chinese logistics industry,there are still many problems to be concerned and resolved.This paper will review the concepts and theoretical background of E-logistics System from previous researches.After acknowledging the essential issues on E-logistics System,a research model is designed and tested based on the Theory Acceptance Model.This research aims to provide theoretical and practical contributions for Chinese logistics companies to enhance understanding on E-logistics System.It also provides some useful theoretical implication and practical guidelines for the development of E-logistics System in Chinese logistics industry. 展开更多
关键词 Chinese logistics INDUSTRY E-logistics process LOG
下载PDF
Unmanned Technology-Based Civil-Military Intelligent Logistics System:From Construction to Integration 被引量:1
10
作者 Zhenxin Sun Qiang Wang +1 位作者 Lei Chen Chun Hu 《Journal of Beijing Institute of Technology》 EI CAS 2022年第2期140-151,共12页
The stockpiling,delivery,and provision of emergency material were in the public gaze of millions of people when the coronavirus disease 2019(COVID-19)broke out.Civil-military integra-tion emergency logistics silently ... The stockpiling,delivery,and provision of emergency material were in the public gaze of millions of people when the coronavirus disease 2019(COVID-19)broke out.Civil-military integra-tion emergency logistics silently opened up the“second battlefield”of anti-epidemic,and estab-lished a lifeline under that emergency situation.Research on the construction of civil-military integ-rated logistics system plays an extremely important role and occupies a significant position in en-suring social stability and security as well as the stable development of social economy in China.The modern economy driven by the Internet,Internet of Things,and big data demonstrates a rap-id growing trend calling for efficient,fast,and convenient logistics.It is urgent to upgrade or build an intelligent logistics system with intelligent technology and unmanned technology as the core to meet the international and domestic market demand.As mentioned above,this paper analyzes and expounds the construction problem and practical significance of civil-military integration emer-gency logistics system based on unmanned technology,and puts forward the strategy of construct-ing civil-military integration emergency logistics system with unmanned technology under the new system. 展开更多
关键词 unmanned technology civil-military integration emergency logistics system construc-tion
下载PDF
Operation Mode and Optimum Design of China's Agricultural Modern Logistics System 被引量:1
11
作者 QIN Shi-bo 《Asian Agricultural Research》 2012年第2期63-66,共4页
Using comparative analysis and logical reasoning methods,in combination with traditional logistics theory and practice,and on the basis of objective demand of modern agricultural development for logistics service,we a... Using comparative analysis and logical reasoning methods,in combination with traditional logistics theory and practice,and on the basis of objective demand of modern agricultural development for logistics service,we analyze features of logistics function.Besides,we discuss functional elements and service contents of agricultural modern logistics.In addition,we explore innovation model of agricultural modern logistics and systematized operation of supply chain.Finally,it is concluded that logistics development shall bring into full play all functional elements and achieve high efficient operation of the system through enhanced management measures. 展开更多
关键词 Agricultural modern logistics Functional elements system optimization
下载PDF
The Current Situation of Agricultural Products Logistics and the Conception of Logistics System in Henan Province:based on the Case of Zhengzhou
12
作者 FAN Bing-xu SUN Xia-ling 《International Journal of Plant Engineering and Management》 2018年第1期24-31,共8页
Based on the understanding of agricultural products, transportation sites and transportation market, this paper puts forward the concept of agricultural product logistics system, and discusses the background of the sy... Based on the understanding of agricultural products, transportation sites and transportation market, this paper puts forward the concept of agricultural product logistics system, and discusses the background of the system and provides recommendations for subsequent protection. Through the research of this paper, we explore the development countenneasures of agricultural products logistics under the background of low-carbon economy to guide the development of agricultural products logistics, improve the economic benefits of agricultural products, promote agricultural development and farmers' income. Finally, the paper discusses the optimization of economic and social environmental benefits, which will contribute to the construction of new socialist countuside in Henan province. 展开更多
关键词 agricultural products logistics green system
下载PDF
Delivery Invoice Information Classification System for Joint Courier Logistics Infrastructure
13
作者 Youngmin Kim Sunwoo Hwang +1 位作者 Jaemin Park Joouk Kim 《Computers, Materials & Continua》 SCIE EI 2023年第5期3027-3044,共18页
With the growth of the online market,demand for logistics and courier cargo is increasing rapidly.Accordingly,in the case of urban areas,road congestion and environmental problems due to cargo vehicles are mainly occu... With the growth of the online market,demand for logistics and courier cargo is increasing rapidly.Accordingly,in the case of urban areas,road congestion and environmental problems due to cargo vehicles are mainly occurring.The joint courier logistics system,a plan to solve this problem,aims to establish an efficient logistics transportation system by utilizing one joint logistics delivery terminal by several logistics and delivery companies.However,several courier companies use different types of courier invoices.Such a system has a problem of information data transmission interruption.Therefore,the data processing process was systematically analyzed,a practically feasible methodology was devised,and delivery invoice information processing standards were established for this.In addition,the importance of this paper can be emphasized in terms of data processing in the logistics sector,which is expected to grow rapidly in the future.The results of this study can be used as basic data for the implementation of the logistics joint delivery terminal system in the future.And it can be used as a basis for securing the operational reliability of the joint courier logistics system. 展开更多
关键词 Joint courier logistics base infrastructure logistics cooperation urban public infrastructure YOLOv4 object detection algorithm
下载PDF
Hybrid Algorithm-Driven Smart Logistics Optimization in IoT-Based Cyber-Physical Systems
14
作者 Abdulwahab Ali Almazroi Nasir Ayub 《Computers, Materials & Continua》 SCIE EI 2023年第12期3921-3942,共22页
Effectively managing complex logistics data is essential for development sustainability and growth,especially in optimizing distribution routes.This article addresses the limitations of current logistics path optimiza... Effectively managing complex logistics data is essential for development sustainability and growth,especially in optimizing distribution routes.This article addresses the limitations of current logistics path optimization methods,such as inefficiencies and high operational costs.To overcome these drawbacks,we introduce the Hybrid Firefly-Spotted Hyena Optimization(HFSHO)algorithm,a novel approach that combines the rapid exploration and global search abilities of the Firefly Algorithm(FO)with the localized search and region-exploitation skills of the Spotted Hyena Optimization Algorithm(SHO).HFSHO aims to improve logistics path optimization and reduce operational costs.The algorithm’s effectiveness is systematically assessed through rigorous comparative analyses with established algorithms like the Ant Colony Algorithm(ACO),Cuckoo Search Algorithm(CSA)and Jaya Algo-rithm(JA).The evaluation also employs benchmarking methodologies using standardized function sets covering diverse objective functions,including Schwefel’s,Rastrigin,Ackley,Sphere and the ZDT and DTLZ Function suite.HFSHO outperforms these algorithms,achieving a minimum path distance of 546 units,highlighting its prowess in logistics path optimization.This comprehensive evaluation authenticates HFSHO’s exceptional performance across various logistic optimization scenarios.These findings emphasize the critical significance of selecting an appropriate algorithm for logistics path navigation,with HFSHO emerging as an efficient choice.Through the synergistic use of FO and SHO,HFSHO achieves a 15%improvement in convergence,heightened operational efficiency and substantial cost reductions in logistics operations.It presents a promising solution for optimizing logistics paths,offering logistics planners and decision-makers valuable insights and contributing substantively to sustainable sectoral growth. 展开更多
关键词 Hybrid optimization internet of things intelligent transport system optimal path finding smart logistics traffic congestion supply chain
下载PDF
Underground logistics systems:Development overview and new prospects in China
15
作者 Wanjie HU Jianjun DONG +1 位作者 Rui REN Zhilong CHEN 《Frontiers of Engineering Management》 CSCD 2023年第2期354-359,共6页
1 Introduction Underground logistics systems(ULSs)are a set of self-contained,multimodal,and intelligent physical distribution concepts that enable the automated movement of goods via tunnels and underground pipelines... 1 Introduction Underground logistics systems(ULSs)are a set of self-contained,multimodal,and intelligent physical distribution concepts that enable the automated movement of goods via tunnels and underground pipelines installed within and between cities(Visser,2018).ULSs are also recognized as the fifth type of logistics and generic supply system after seaways,airlines,roads,and railways(Qian and Guo,2007). 展开更多
关键词 UNDERGROUND enable logistics
原文传递
基于logistics回归模型的山洪泥石流风险评估
16
作者 纪洪源 杨奉广 《吉林水利》 2024年第4期1-6,46,共7页
山洪泥石流作为一种常见的自然灾害,其突发性和破坏性给人类社会的生产生活带来了巨大的威胁。在全球气候变暖的背景下,山洪泥石流的发生频率和破坏力呈现增加趋势。通过采用有序logistics回归模型,对四川省北川羌族自治县地区山洪泥石... 山洪泥石流作为一种常见的自然灾害,其突发性和破坏性给人类社会的生产生活带来了巨大的威胁。在全球气候变暖的背景下,山洪泥石流的发生频率和破坏力呈现增加趋势。通过采用有序logistics回归模型,对四川省北川羌族自治县地区山洪泥石流危险性进行了定量化评估,选取流域切割密度、流域相对高差、主沟长度、50年一遇泥石流规模等多个关键因素,构建了logistics回归模型进行危险性评估。根据模型结果发现,主沟长度和50年一遇规模的影响最为显著。本文不仅对山洪泥石流风险进行了较为精确的定量化评估,同时也为防治措施的制定提供了科学依据。 展开更多
关键词 山洪泥石流 有序logistics回归 危险性评估
下载PDF
A Proposed Feature Selection Particle Swarm Optimization Adaptation for Intelligent Logistics--A Supply Chain Backlog Elimination Framework
17
作者 Yasser Hachaichi Ayman E.Khedr Amira M.Idrees 《Computers, Materials & Continua》 SCIE EI 2024年第6期4081-4105,共25页
The diversity of data sources resulted in seeking effective manipulation and dissemination.The challenge that arises from the increasing dimensionality has a negative effect on the computation performance,efficiency,a... The diversity of data sources resulted in seeking effective manipulation and dissemination.The challenge that arises from the increasing dimensionality has a negative effect on the computation performance,efficiency,and stability of computing.One of the most successful optimization algorithms is Particle Swarm Optimization(PSO)which has proved its effectiveness in exploring the highest influencing features in the search space based on its fast convergence and the ability to utilize a small set of parameters in the search task.This research proposes an effective enhancement of PSO that tackles the challenge of randomness search which directly enhances PSO performance.On the other hand,this research proposes a generic intelligent framework for early prediction of orders delay and eliminate orders backlogs which could be considered as an efficient potential solution for raising the supply chain performance.The proposed adapted algorithm has been applied to a supply chain dataset which minimized the features set from twenty-one features to ten significant features.To confirm the proposed algorithm results,the updated data has been examined by eight of the well-known classification algorithms which reached a minimum accuracy percentage equal to 94.3%for random forest and a maximum of 99.0 for Naïve Bayes.Moreover,the proposed algorithm adaptation has been compared with other proposed adaptations of PSO from the literature over different datasets.The proposed PSO adaptation reached a higher accuracy compared with the literature ranging from 97.8 to 99.36 which also proved the advancement of the current research. 展开更多
关键词 Optimization particle swarm optimization algorithm feature selection logistics supply chain management backlogs
下载PDF
Using Improved Particle Swarm Optimization Algorithm for Location Problem of Drone Logistics Hub
18
作者 Li Zheng Gang Xu Wenbin Chen 《Computers, Materials & Continua》 SCIE EI 2024年第1期935-957,共23页
Drone logistics is a novel method of distribution that will become prevalent.The advantageous location of the logistics hub enables quicker customer deliveries and lower fuel consumption,resulting in cost savings for ... Drone logistics is a novel method of distribution that will become prevalent.The advantageous location of the logistics hub enables quicker customer deliveries and lower fuel consumption,resulting in cost savings for the company’s transportation operations.Logistics firms must discern the ideal location for establishing a logistics hub,which is challenging due to the simplicity of existing models and the intricate delivery factors.To simulate the drone logistics environment,this study presents a new mathematical model.The model not only retains the aspects of the current models,but also considers the degree of transportation difficulty from the logistics hub to the village,the capacity of drones for transportation,and the distribution of logistics hub locations.Moreover,this paper proposes an improved particle swarm optimization(PSO)algorithm which is a diversity-based hybrid PSO(DHPSO)algorithm to solve this model.In DHPSO,the Gaussian random walk can enhance global search in the model space,while the bubble-net attacking strategy can speed convergence.Besides,Archimedes spiral strategy is employed to overcome the local optima trap in the model and improve the exploitation of the algorithm.DHPSO maintains a balance between exploration and exploitation while better defining the distribution of logistics hub locations Numerical experiments show that the newly proposed model always achieves better locations than the current model.Comparing DHPSO with other state-of-the-art intelligent algorithms,the efficiency of the scheme can be improved by 42.58%.This means that logistics companies can reduce distribution costs and consumers can enjoy a more enjoyable shopping experience by using DHPSO’s location selection.All the results show the location of the drone logistics hub is solved by DHPSO effectively. 展开更多
关键词 Drone logistics location problem mathematical model DIVERSITY particle swarm optimization
下载PDF
GLOBAL WEAK SOLUTIONS FOR AN ATTRACTION-REPULSION CHEMOTAXIS SYSTEM WITH p-LAPLACIAN DIFFUSION AND LOGISTIC SOURCE
19
作者 王晓闪 王忠谦 贾哲 《Acta Mathematica Scientia》 SCIE CSCD 2024年第3期909-924,共16页
This paper is concerned with the following attraction-repulsion chemotaxis system with p-Laplacian diffusion and logistic source:■The system here is under a homogenous Neumann boundary condition in a bounded domainΩ... This paper is concerned with the following attraction-repulsion chemotaxis system with p-Laplacian diffusion and logistic source:■The system here is under a homogenous Neumann boundary condition in a bounded domainΩ ■ R^(n)(n≥2),with χ,ξ,α,β,γ,δ,k_(1),k_(2)> 0,p> 2.In addition,the function f is smooth and satisfies that f(s)≤κ-μs~l for all s≥0,with κ ∈ R,μ> 0,l> 1.It is shown that(ⅰ)if l> max{2k_(1),(2k_(1)n)/(2+n)+1/(p-1)},then system possesses a global bounded weak solution and(ⅱ)if k_(2)> max{2k_(1)-1,(2k_(1)n)/(2+n)+(2-p)/(p-1)} with l> 2,then system possesses a global bounded weak solution. 展开更多
关键词 global weak solutions attraction-repulsion P-LAPLACIAN logistic source
下载PDF
普外科术中低体温发生情况Logistics回归分析及预测模型构建
20
作者 方丹 施静婧 《新疆医科大学学报》 CAS 2024年第1期98-102,108,共6页
目的探讨普外科术中低体温发生的风险因素,构建并验证术中低体温发生的风险预测模型。方法选取2020年12月至2022年12月在本院接受普外科手术的117例患者作为观察对象。收集患者临床资料,根据患者术中是否发生低体温将其分为发生低体温... 目的探讨普外科术中低体温发生的风险因素,构建并验证术中低体温发生的风险预测模型。方法选取2020年12月至2022年12月在本院接受普外科手术的117例患者作为观察对象。收集患者临床资料,根据患者术中是否发生低体温将其分为发生低体温组(A组)和未发生低体温组(B组)。Logistic回归分析影响患者普外科术中发生低体温的危险因素,并建立风险预测模型,受试者工作特征曲线(ROC)检测该模型的预测效能。结果117例患者中发生低体温31例(26.49%),未发生低体温86例(73.50%)。两组患者在年龄、体重指数、手术方式、ASA分级、术中输液量、手术室温、手术时间等方面比较,差异具有统计学意义(P<0.05)。Logistic回归分析结果显示,年龄≥65岁、术中输液量≥1000 mL、麻醉时间≥4 h、手术室温<23℃是普外科术中发生低体温的危险因素(P<0.05)。独立危险因素纳入Logistic回归分析并建立预测模型,模型预测概率P=1/[1+e(-1.020+0.874)×(年龄)+1.114×(术中输液量)+1.556×(手术室温)+1.453×(麻醉时间)]。ROC曲线检验该模型预测效能,结果显示ROC曲线下面积(AUC)=0.754(P<0.05);Hosmer-Lemeshow拟合优度检验显示,χ^(2)=1.001,P=0.998。结论患者年龄、术中输液量、麻醉时间、手术室温是普外科患者术中发生低体温的独立危险因素,Logistic风险预测模型拟合效度好,具有较高预测价值。 展开更多
关键词 外科手术 低体温 logistics回归分析 预测模型构建
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部