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Using Improved Particle Swarm Optimization Algorithm for Location Problem of Drone Logistics Hub
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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
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The heterogeneous impact of China-Europe railway express on the efficiency of logistics industry in node cities
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作者 Yanliang Niu Jin Liu +1 位作者 Xining Yang Chuan Wang 《Railway Sciences》 2024年第3期279-294,共16页
Purpose-The spatiotemporal compression effect of China-Europe Railway Express(CR-Express)can reduce the filow costs of resources between China's node cities.Additionally,it can break through the limitations of low... Purpose-The spatiotemporal compression effect of China-Europe Railway Express(CR-Express)can reduce the filow costs of resources between China's node cities.Additionally,it can break through the limitations of low-added-value marine products,significantly impacting the logistics industry efficiency.However,there are few literature verifying and analyzing its heterogeneity.This study explores the impact of CR-Express on the efficiency of logistics industry in node cities and analyzes the heterogeneity.Design/methodology/approach-First,this study uses panel data to measure the efficiency of node city logistics industry.Secondiy,this study discusses the impact of the opening of CR-Express on the efficiency of logistics industry in node cities based on the multi-period differential model.Finally,according to the node city difference,the sample city experimental group is grouped for heterogeneity analysis.Findings-The results show that CR-Express can promote the urban logistics industry efficiency,with an average effect of 4.55%.According to the urban characteristics classification,the heterogeneity analysis shows that the efficiency improvement effect of logistics industry in inland cities is more obvious.The improvement effect of node cities and central cities in central and western China is stronger,especially in the sample of megacities and type I big cities.Compared with non-value chain industrial products,the CR-Express has significant promotion effects on the logistics efficiency of the cities where main goods are value chain products.Originality/value-Under the background of double cycle development,this paper can provide a scientific basis for the investment benefit evaluation of CR-Express construction and the follow-up route planning. 展开更多
关键词 logistics industry efficiency China-Europe railway express Difference-in-difference model HETEROGENEitY Transportation infrastructure Paper type Research paper
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Development status and prospect of cold chain logistics of fruits,vegetables,and agricultural products based on intelligent technology
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作者 ZHANG Ruizhi LIU Qianyuan +3 位作者 HUANG Yuying LIU Bing CHANG Zhiguang WANG Jiaoling 《智能化农业装备学报(中英文)》 2024年第3期63-74,共12页
The cold chain in the production area of fruits and vegetables is the primary link to reduce product loss and improve product quality,but it is also a weak link.With the application of big data technology in cold chai... The cold chain in the production area of fruits and vegetables is the primary link to reduce product loss and improve product quality,but it is also a weak link.With the application of big data technology in cold chain logistics,intelligent devices,and technologies have become important carriers for improving the efficiency of cold chain logistics in fruit and vegetable production areas,extending the shelf life of fruits and vegetables,and reducing fruit and vegetable losses.They have many advantages in fruit and vegetable pre-cooling,sorting and packaging,testing,warehousing,transportation,and other aspects.This article summarizes the rapidly developing and widely used intelligent technologies at home and abroad in recent years,including automated guided vehicle intelligent handling based on electromagnetic or optical technology,intelligent sorting based on sensors,electronic optics,and other technologies,intelligent detection based on computer vision technology,intelligent transportation based on perspective imaging technology,etc.It analyses and studies the innovative research and achievements of various scholars in applying intelligent technology in fruit and vegetable cold chain storage,sorting,detection,transportation,and other links,and improves the efficiency of fruit and vegetable cold chain logistics.However,applying intelligent technology in fruit and vegetable cold chain logistics also faces many problems.The challenges of high cost,difficulty in technological integration,and talent shortages have limited the development of intelligent technology in the field of fruit and vegetable cold chains.To solve the current problems,it is proposed that costs be controlled through independent research and development,technological innovation,and other means to lower the entry threshold for small enterprises.Strengthen integrating intelligent technology and cold chain logistics systems to improve data security and system compatibility.At the same time,the government should introduce relevant policies,provide necessary financial support,and establish talent training mechanisms.Accelerate the development and improvement of intelligent technology standards in the field of cold chain logistics.Through technological innovation,cost control,talent cultivation,and policy guidance,we aim to promote the upgrading of the agricultural industry and provide ideas for improving the quality and efficiency of fruit and vegetable cold chain logistics. 展开更多
关键词 fruits and vegetables cold chain logistics automated guided vehicle intelligent handling computer vision spectral detection
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Stackelberg Game-Based Resource Allocation with Blockchain for Cold-Chain Logistics System 被引量:1
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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
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Hybrid Algorithm-Driven Smart Logistics Optimization in IoT-Based Cyber-Physical Systems
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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
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Problems and Countermeasures of Fruit and Vegetable Logistics Distribution Development in Guangxi Zhuang Autonomous Region
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作者 Xi XU Bihong FENG 《Asian Agricultural Research》 2023年第10期1-5,9,共6页
The logistics transportation and distribution of fruits and vegetables has become one of the important links for people to obtain food,and it is also an important direction and emerging challenge in the logistics indu... The logistics transportation and distribution of fruits and vegetables has become one of the important links for people to obtain food,and it is also an important direction and emerging challenge in the logistics industry.As the social economy and transportation develop,the consumption ability of residents has been improved,and the high demand for fruits and vegetables has promoted the transportation of fruits and vegetables to meet the development conditions of the future fruit and vegetable industry.The study of fruit and vegetable logistics distribution can improve the efficiency of fruit and vegetable distribution,improve the construction of fruit and vegetable distribution system,and also meet the needs of people for different kinds of fruits and vegetables.Taking Guangxi fruit and vegetable distribution as an example,through empirical investigation,this paper studies the existing problems in the development of logistics distribution in the fruit and vegetable distribution industry,and puts forward corresponding measures and countermeasures according to the problems,so as to innovate the fruit and vegetable distribution mode in Guangxi Zhuang Autonomous Region. 展开更多
关键词 Fruit and vegetable distribution Fruit and vegetable logistics DEVELOPMENT
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Exploration on the Construction of University Logistics Information Service Platform
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作者 Man Liu Rong Su 《Intelligent Information Management》 2023年第1期1-10,共10页
Logistics information construction in colleges and universities is an important part of smart campus. This paper expounds the current situation and existing problems of the logistics information construction in colleg... Logistics information construction in colleges and universities is an important part of smart campus. This paper expounds the current situation and existing problems of the logistics information construction in colleges and universities. Taking China University of Geosciences (Beijing) as an example, this paper discusses the construction principles and Personnel organization structure of the logistics information construction, and provides the construction scheme of the logistics information service platform. It can be used for reference for the implementation of logistics information construction in other colleges and universities. 展开更多
关键词 University logistics logistics Information Construction Smart Campus
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基于logistics回归模型的山洪泥石流风险评估
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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
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The Role of Chittagong Port Authority to Develop Other National Ports in Bangladesh to Provide Maritime Logistics Support in South Asia
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作者 Razon Chandra Saha 《Sustainable Marine Structures》 2023年第1期24-36,共13页
Chittagong Port is the principal seaport in Bangladesh that has contributed to the national economy with the opportunity to be a world-class regional port in South Asia.Cooperation among the three national ports Chitt... Chittagong Port is the principal seaport in Bangladesh that has contributed to the national economy with the opportunity to be a world-class regional port in South Asia.Cooperation among the three national ports Chittagong,Mongla and Payra is essential to do maritime logistics business in the region after serving the nation proudly.Here,Chittagong Port Authority(CPA)has the opportunity to help others in the process of port development for increasing efficiency and productivity by providing financial and technical assistance because of its financial and technical capabilities as a pioneer seaport in the port world.This paper examines the role of CPA to bolster and develop the underutilized Mongla Port and newly established Payra Port,where qualitative research methodology is applied to explore the ways,by which CPA can assist,link and integrate with others effectively,especially in developing the port infrastructure and inland transport networks.In addition,the research found the prospectus of Mongla and Payra to supply port services to the neighbors India,Nepal,and Bhutan as well as serve the South-West part of China with the aim of increasing regional connectivity and promoting international trade in those basically landlocked areas and countries of Asia. 展开更多
关键词 BANGLADESH MARitIME logistics Qualitative China CONNECTIVitY
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A Proposed Feature Selection Particle Swarm Optimization Adaptation for Intelligent Logistics--A Supply Chain Backlog Elimination Framework
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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
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Two-dimensional-lag complex logistic map with complex parameters and its encryption application
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作者 张芳芳 武金波 +3 位作者 寇磊 马凤英 吴黎明 张雪 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第5期324-335,共12页
With the rapid development of internet technology,security protection of information has become more and more prominent,especially information encryption.Considering the great advantages of chaotic encryption,we propo... With the rapid development of internet technology,security protection of information has become more and more prominent,especially information encryption.Considering the great advantages of chaotic encryption,we propose a 2D-lag complex logistic map with complex parameters(2D-LCLMCP)and corresponding encryption schemes.Firstly,we present the model of the 2D-LCLMCP and analyze its chaotic properties and system stability through fixed points,Lyapunov exponent,bifurcation diagram,phase diagram,etc.Secondly,a block cipher algorithm based on the 2D-LCLMCP is proposed,the plaintext data is preprocessed using a pseudorandom sequence generated by the 2D-LCLMCP.Based on the generalized Feistel cipher structure,a round function F is constructed using dynamic S-box and DNA encoding rules as the core of the block cipher algorithm.The generalized Feistel cipher structure consists of two F functions,four XOR operations,and one permutation operation per round.The symmetric dynamic round keys that change with the plaintext are generated by the 2D-LCLMCP.Finally,experimental simulation and performance analysis tests are conducted.The results show that the block cipher algorithm has low complexit,good diffusion and a large key space.When the block length is 64 bits,only six rounds of encryption are required to provide sufficient security and robustness against cryptographic attacks. 展开更多
关键词 logistic map block ciphers chaotic system ENCRYPTION
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DYNAMICS FOR A CHEMOTAXIS MODEL WITH GENERAL LOGISTIC DAMPING AND SIGNAL DEPENDENT MOTILITY
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作者 涂馨予 穆春来 +1 位作者 邱蜀燕 张静 《Acta Mathematica Scientia》 SCIE CSCD 2024年第3期1046-1063,共18页
In this paper,we consider the fully parabolic Chemotaxis system with the general logistic source{ut=Δ(γ(v)u)+λu-μu^(k),x∈Ω,t>0,vt=△v+wz,x∈Ω,t>0,wt=-wz,x∈Ω,t>0,zt=△z-z+u,x∈Ω,t>0 whereΩ⊂ℝn(n≥... In this paper,we consider the fully parabolic Chemotaxis system with the general logistic source{ut=Δ(γ(v)u)+λu-μu^(k),x∈Ω,t>0,vt=△v+wz,x∈Ω,t>0,wt=-wz,x∈Ω,t>0,zt=△z-z+u,x∈Ω,t>0 whereΩ⊂ℝn(n≥1)is a smooth and bounded domain,λ≥0,μ≥0,κ>1,and the motility function satisfies thatγ(v)∈C3([0,∞)),γ(v)>0,γ′(v)≤0 for all v≥0.Considering the Neumann boundary condition,we obtain the global boundedness of solutions if one of the following conditions holds:(i)λ=μ=0,1≤nλ3;(ii)λ>0,μ>0,combined withκ>1,1≤n≤3 or k>n+2/4,,n>3.Moreover,we prove that the solution (u, v, w, z) exponentially converges to the constant steady state ((λ/μ)1/k-1,∫Ωv0dx+∫Ωw0dx/|Ω|,0,(λ/μ)1/k-1). 展开更多
关键词 CHEMOTAXIS signal-dependent motility logistic source boundedness asymptotic behavior
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GLOBAL WEAK SOLUTIONS FOR AN ATTRACTION-REPULSION CHEMOTAXIS SYSTEM WITH p-LAPLACIAN DIFFUSION AND LOGISTIC SOURCE
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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
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A whole process damage constitutive model for layered sandstone under uniaxial compression based on Logistic function
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作者 LIU Dong-qiao GUO Yun-peng +1 位作者 LING Kai LI Jie-yu 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2411-2430,共20页
Bedding structural planes significantly influence the mechanical properties and stability of engineering rock masses.This study conducts uniaxial compression tests on layered sandstone with various bedding angles(0... Bedding structural planes significantly influence the mechanical properties and stability of engineering rock masses.This study conducts uniaxial compression tests on layered sandstone with various bedding angles(0°,15°,30°,45°,60°,75°and 90°)to explore the impact of bedding angle on the deformational mechanical response,failure mode,and damage evolution processes of rocks.It develops a damage model based on the Logistic equation derived from the modulus’s degradation considering the combined effect of the sandstone bedding dip angle and load.This model is employed to study the damage accumulation state and its evolution within the layered rock mass.This research also introduces a piecewise constitutive model that considers the initial compaction characteristics to simulate the whole deformation process of layered sandstone under uniaxial compression.The results revealed that as the bedding angle increases from 0°to 90°,the uniaxial compressive strength and elastic modulus of layered sandstone significantly decrease,slightly increase,and then decline again.The corresponding failure modes transition from splitting tensile failure to slipping shear failure and back to splitting tensile failure.As indicated by the modulus’s degradation,the damage characteristics can be categorized into four stages:initial no damage,damage initiation,damage acceleration,and damage deceleration termination.The theoretical damage model based on the Logistic equation effectively simulates and predicts the entire damage evolution process.Moreover,the theoretical constitutive model curves closely align with the actual stress−strain curves of layered sandstone under uniaxial compression.The introduced constitutive model is concise,with fewer parameters,a straightforward parameter determination process,and a clear physical interpretation.This study offers valuable insights into the theory of layered rock mechanics and holds implications for ensuring the safety of rock engineering. 展开更多
关键词 layered sandstone uniaxial compression damage evolution Logistic function constitutive model
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普外科术中低体温发生情况Logistics回归分析及预测模型构建
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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
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Synergistic effects of planting density and nitrogen fertilization on chlorophyll degradation and leaf senescence after silking in maize
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作者 Tianqiong Lan Lunjing Du +9 位作者 Xinglong Wang Xiaoxu Zhan Qinlin Liu Gui Wei Chengcheng Lyu Fan Liu Jiaxu Gao Dongju Feng Fanlei Kong Jichao Yuan 《The Crop Journal》 SCIE CSCD 2024年第2期605-613,共9页
Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the act... Regulating planting density and nitrogen(N)fertilization could delay chlorophyll(Chl)degradation and leaf senescence in maize cultivars.This study measured changes in ear leaf green area(GLA_(ear)),Chl content,the activities of Chl a-degrading enzymes after silking,and the post-silking dry matter accumulation and grain yield under multiple planting densities and N fertilization rates.The dynamic change of GLA_(ear)after silking fitted to the logistic model,and the GLA_(ear) duration and the GLAearat 42 d after silking were affected mainly by the duration of the initial senescence period(T_(1))which was a key factor of the leaf senescence.The average chlorophyllase(CLH)activity was 8.3 times higher than pheophytinase activity and contributed most to the Chl content,indicating that CLH is a key enzyme for degrading Chl a in maize.Increasing density increased the CLH activity and decreased the Chl content,T1,GLAear,and GLA_(ear) duration.Under high density,appropriate N application reduced CLH activity,increased Chl content,prolonged T1,alleviated high-density-induced leaf senescence,and increased post-silking dry matter accumulation and grain yield. 展开更多
关键词 DENSitY Nitrogen fertilization Leaf senescence Chlorophyll-degrading enzyme Logistic model
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Evaluation of rainfall threshold models for debris flow initiation in the Jiangjia Gully,Yunnan Province,China
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作者 YANG Hongjuan ZHANG Shaojie +2 位作者 HU Kaiheng WEI Fangqiang LIU Yanhui 《Journal of Mountain Science》 SCIE CSCD 2024年第6期1799-1813,共15页
Systematically determining the discriminatory power of various rainfall properties and their combinations in identifying debris flow occurrence is crucial for early warning systems.In this study,we evaluated the discr... Systematically determining the discriminatory power of various rainfall properties and their combinations in identifying debris flow occurrence is crucial for early warning systems.In this study,we evaluated the discriminatory power of different univariate and multivariate rainfall threshold models in identifying triggering conditions of debris flow in the Jiangjia Gully,Yunnan Province,China.The univariate models used single rainfall properties as indicators,including total rainfall(R_(tot)),rainfall duration(D),mean intensity(I_(mean)),absolute energy(Eabs),storm kinetic energy(E_(s)),antecedent rainfall(R_(a)),and maximum rainfall intensity over various durations(I_(max_dur)).The evaluation reveals that the I_(max_dur)and Eabs models have the best performance,followed by the E_(s),R_(tot),and I_(mean)models,while the D and R_(a)models have poor performances.Specifically,the I_(max_dur)model has the highest performance metrics at a 40-min duration.We used logistic regression to combine at least two rainfall properties to establish multivariate threshold models.The results show that adding D or R_(a)to the models dominated by Eabs,E_(s),R_(tot),or I_(mean)generally improve their performances,specifically when D is combined with I_(mean)or when R_(a)is combined with Eabs or E_(s).Including R_(a)in the I_(max_dur)model,it performs better than the univariate I_(max_dur)model.A power-law relationship between I_(max_dur)and R_(a)or between Eabs and R_(a)has better performance than the traditional I_(mean)–D model,while the performance of the E_(s)–R_(a)model is moderate.Our evaluation reemphasizes the important role of the maximum intensity over short durations in debris flow occurrence.It also highlights the importance of systematically investigating the role of R_(a)in establishing rainfall thresholds for triggering debris flow.Given the regional variations in rainfall patterns worldwide,it is necessary to evaluate the findings of this study across diverse watersheds. 展开更多
关键词 Rainfall threshold Logistic regression Maximum rainfall intensity Absolute energy Antecedent rainfall
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Integration of Multiple Spectral Data via a Logistic Regression Algorithm for Detection of Crop Residue Burned Areas:A Case Study of Songnen Plain,Northeast China
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作者 ZHANG Sumei ZHANG Yuan ZHAO Hongmei 《Chinese Geographical Science》 SCIE CSCD 2024年第3期548-563,共16页
The burning of crop residues in fields is a significant global biomass burning activity which is a key element of the terrestrial carbon cycle,and an important source of atmospheric trace gasses and aerosols.Accurate ... The burning of crop residues in fields is a significant global biomass burning activity which is a key element of the terrestrial carbon cycle,and an important source of atmospheric trace gasses and aerosols.Accurate estimation of cropland burned area is both crucial and challenging,especially for the small and fragmented burned scars in China.Here we developed an automated burned area mapping algorithm that was implemented using Sentinel-2 Multi Spectral Instrument(MSI)data and its effectiveness was tested taking Songnen Plain,Northeast China as a case using satellite image of 2020.We employed a logistic regression method for integrating multiple spectral data into a synthetic indicator,and compared the results with manually interpreted burned area reference maps and the Moderate-Resolution Imaging Spectroradiometer(MODIS)MCD64A1 burned area product.The overall accuracy of the single variable logistic regression was 77.38%to 86.90%and 73.47%to 97.14%for the 52TCQ and 51TYM cases,respectively.In comparison,the accuracy of the burned area map was improved to 87.14%and 98.33%for the 52TCQ and 51TYM cases,respectively by multiple variable logistic regression of Sentind-2 images.The balance of omission error and commission error was also improved.The integration of multiple spectral data combined with a logistic regression method proves to be effective for burned area detection,offering a highly automated process with an automatic threshold determination mechanism.This method exhibits excellent extensibility and flexibility taking the image tile as the operating unit.It is suitable for burned area detection at a regional scale and can also be implemented with other satellite data. 展开更多
关键词 crop residue burning burned area Sentinel-2 Multi Spectral Instrument(MSI) logistic regression Songnen Plain China
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Comparative study of different machine learning models in landslide susceptibility assessment: A case study of Conghua District, Guangzhou, China
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作者 Ao Zhang Xin-wen Zhao +8 位作者 Xing-yuezi Zhao Xiao-zhan Zheng Min Zeng Xuan Huang Pan Wu Tuo Jiang Shi-chang Wang Jun He Yi-yong Li 《China Geology》 CAS CSCD 2024年第1期104-115,共12页
Machine learning is currently one of the research hotspots in the field of landslide prediction.To clarify and evaluate the differences in characteristics and prediction effects of different machine learning models,Co... Machine learning is currently one of the research hotspots in the field of landslide prediction.To clarify and evaluate the differences in characteristics and prediction effects of different machine learning models,Conghua District,which is the most prone to landslide disasters in Guangzhou,was selected for landslide susceptibility evaluation.The evaluation factors were selected by using correlation analysis and variance expansion factor method.Applying four machine learning methods namely Logistic Regression(LR),Random Forest(RF),Support Vector Machines(SVM),and Extreme Gradient Boosting(XGB),landslide models were constructed.Comparative analysis and evaluation of the model were conducted through statistical indices and receiver operating characteristic(ROC)curves.The results showed that LR,RF,SVM,and XGB models have good predictive performance for landslide susceptibility,with the area under curve(AUC)values of 0.752,0.965,0.996,and 0.998,respectively.XGB model had the highest predictive ability,followed by RF model,SVM model,and LR model.The frequency ratio(FR)accuracy of LR,RF,SVM,and XGB models was 0.775,0.842,0.759,and 0.822,respectively.RF and XGB models were superior to LR and SVM models,indicating that the integrated algorithm has better predictive ability than a single classification algorithm in regional landslide classification problems. 展开更多
关键词 Landslides susceptibility assessment Machine learning Logistic Regression Random Forest Support Vector Machines XGBoost Assessment model Geological disaster investigation and prevention engineering
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Harvesting Technologies and Costs for Switchgrass Production
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作者 Hana Toth Jude Liu 《Advances in Bioscience and Biotechnology》 CAS 2024年第2期112-128,共17页
As today’s society searches for renewable energy sources that could be an alternative to fossil fuels, biomass and biofuels provide a promising solution. Switchgrass is one of feedstocks that can be utilized as a ren... As today’s society searches for renewable energy sources that could be an alternative to fossil fuels, biomass and biofuels provide a promising solution. Switchgrass is one of feedstocks that can be utilized as a renewable energy source. When farming, one of the most important considerations is efficiency. This consists of several factors, including time, fuel use, economic and power efficiencies of equipment. Inefficient field operations could increase harvesting costs and in turn could cause hesitation when a farmer decides to participate in biomass production. This literature review will cover the main elements of biomass and biomass handling relating to determining harvesting efficiency and biomass quality for switchgrass round bales. Specifically, the following sections include past research activities relating to biomass harvesting, biomass bale quality during outdoor storage, logistics models, and data collection methods during biomass harvesting. The objective of this review is to examine status and needs for switchgrass round bale harvesting operations and the expenses that come with it. 展开更多
关键词 BIOMASS BALING Energy Crop logistics
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