Improving the cooperative scheduling efficiency of equipment is the key for automated container terminals to copewith the development trend of large-scale ships. In order to improve the solution efficiency of the exis...Improving the cooperative scheduling efficiency of equipment is the key for automated container terminals to copewith the development trend of large-scale ships. In order to improve the solution efficiency of the existing spacetimenetwork (STN) model for the cooperative scheduling problem of yard cranes (YCs) and automated guidedvehicles (AGVs) and extend its application scenarios, two improved STN models are proposed. The flow balanceconstraints in the original model are decomposed, and the trajectory constraints of YCs and AGVs are added toacquire the model STN_A. The coupling constraint in STN_A is updated, and buffer constraints are added toSTN_A so that themodel STN_B is built.As the size of the problem increases, the solution speed of CPLEX becomesthe bottleneck. So a heuristic method containing three groups of heuristic rules is designed to obtain a near-optimalsolution quickly. Experimental results showthat the computation time of STN_A is shortened by 49.47% on averageand the gap is reduced by 1.69% on average compared with the original model. The gap between the solution ofthe heuristic rules and the solution of CPLEX is less than 3.50%, and the solution time of the heuristic rules is onaverage 99.85% less than the solution time of CPLEX. Compared with STN_A, the computation time for solvingSTN_B increases by 58.93% on average.展开更多
Marine container terminal(MCT)plays a key role in the marine intelligent transportation system and international logistics system.However,the efficiency of resource scheduling significantly influences the operation pe...Marine container terminal(MCT)plays a key role in the marine intelligent transportation system and international logistics system.However,the efficiency of resource scheduling significantly influences the operation performance of MCT.To solve the practical resource scheduling problem(RSP)in MCT efficiently,this paper has contributions to both the problem model and the algorithm design.Firstly,in the problem model,different from most of the existing studies that only consider scheduling part of the resources in MCT,we propose a unified mathematical model for formulating an integrated RSP.The new integrated RSP model allocates and schedules multiple MCT resources simultaneously by taking the total cost minimization as the objective.Secondly,in the algorithm design,a pre-selection-based ant colony system(PACS)approach is proposed based on graphic structure solution representation and a pre-selection strategy.On the one hand,as the RSP can be formulated as the shortest path problem on the directed complete graph,the graphic structure is proposed to represent the solution encoding to consider multiple constraints and multiple factors of the RSP,which effectively avoids the generation of infeasible solutions.On the other hand,the pre-selection strategy aims to reduce the computational burden of PACS and to fast obtain a higher-quality solution.To evaluate the performance of the proposed novel PACS in solving the new integrated RSP model,a set of test cases with different sizes is conducted.Experimental results and comparisons show the effectiveness and efficiency of the PACS algorithm,which can significantly outperform other state-of-the-art algorithms.展开更多
Internet of Vehicles(IoV)applications integrating with edge com-puting will significantly drive the growth of IoV.However,the contradiction between the high-speed mobility of vehicles,the delay sensitivity of corre-sp...Internet of Vehicles(IoV)applications integrating with edge com-puting will significantly drive the growth of IoV.However,the contradiction between the high-speed mobility of vehicles,the delay sensitivity of corre-sponding IoV applications and the limited coverage and resource capacity of distributed edge servers will pose challenges to the service continuity and stability of IoV applications.IoV application migration is a promising solution that can be supported by application containerization,a technology for seamless cross-edge-server application migration without user perception.Therefore,this paper proposes the container-based IoV edge application migration mechanism,consisting of three parts.The first is the migration trigger determination algorithm for cross-border migration and service degra-dation migration,respectively,based on trajectory prediction and traffic awareness to improve the determination accuracy.The second is the migration target decision calculation model for minimizing the average migration time and maximizing the average service time to reduce migration times and improve the stability and adaptability of migration decisions.The third is the migration decision algorithm based on the improved artificial bee colony algorithm to avoid local optimal migration decisions.Simulation results show that the proposed migration mechanism can reduce migration times,reduce average migration time,improve average service time and enhance the stability and adaptability of IoV application services.展开更多
Coating technologies are a commonly used way to protect metals against corrosion.However,with more and more severe service environments of materials,many protective coating systems often are not environmentally friend...Coating technologies are a commonly used way to protect metals against corrosion.However,with more and more severe service environments of materials,many protective coating systems often are not environmentally friendly or toxic as in the case of chromates.Based on the world’s abundant ideal magnesium(Mg)and its alloy,the smart self-healing anticorrosive coating can autonomously restore the damaged part of the coating according to the environmental changes,strengthen the corrosion protection ability,and prolong its service life.This paper reviews the research progress of smart self-healing coatings on Mg alloys.These coatings mostly contain suitable corrosion inhibitors encapsulated into micro/nano containers.Moreover,the different self-healing mechanisms and functionalities of micro/nano containers are discussed.The micro/nano containers range from inorganic nanocontainers such as mesoporous nanoparticles(silica(SiO_(2)),titanium dioxide(TiO_(2)),etc.),over inorganic clays(halloysite,hydrotalcite-like,zeolite),to organic nanocontainers such as polymer microcapsules,nanofibers,chitosan(CS)and cyclodextrin(CD),as well as,carbon materials such as graphene and carbon nanotubes and hybrids such as metal organic frameworks.The functioning of micro/nano containers can be divided in two principal groups:autonomous(based on defect filling and corrosion inhibition)and non-autonomous(based on dynamic bonds and shape memory polymers).Moreover,multi functionalities and composite applications of various micro/nano containers are summarized.At present,significant progress has been made in the preparation methods and technologies of micro/nano containers.Achieving long-term self-healing properties of coatings sensing of coating failure and early warning after self-healing function failure can be expected as the main development direction of self-healing corrosion protection coatings in the future.展开更多
A nonlinear semi-analytical scheme is proposed for investigating the finiteamplitude nonlinear sloshing in a horizontally baffled rectangular liquid container under the seismic excitation.The sub-domain method is deve...A nonlinear semi-analytical scheme is proposed for investigating the finiteamplitude nonlinear sloshing in a horizontally baffled rectangular liquid container under the seismic excitation.The sub-domain method is developed to analytically derive the modal behaviors of the baffled linear sloshing.The viscosity dissipation effects from the interior liquid and boundary layers are considered.With the introduction of the generalized time-dependent coordinates,the surface wave elevation and velocity potential are represented by a series of linear modal eigenfunctions.The infinite-dimensional modal system of the nonlinear sloshing is formulated based on the Bateman-Luke variational principle,which is further reduced to the finite-dimensional modal system by using the NarimanovMoiseev asymptotic ordering.The base force and overturning moment induced by the nonlinear sloshing are derived as the functions of the generalized time-dependent coordinates.The present results match well with the available analytical,numerical,and experimental results.The paper examines the surface wave elevation,base force,and overturning moment versus the baffle parameters and excitation amplitude in detail.展开更多
Kubernetes is an open-source container management tool which automates container deployment,container load balancing and container(de)scaling,including Horizontal Pod Autoscaler(HPA),Vertical Pod Autoscaler(VPA).HPA e...Kubernetes is an open-source container management tool which automates container deployment,container load balancing and container(de)scaling,including Horizontal Pod Autoscaler(HPA),Vertical Pod Autoscaler(VPA).HPA enables flawless operation,interactively scaling the number of resource units,or pods,without downtime.Default Resource Metrics,such as CPU and memory use of host machines and pods,are monitored by Kubernetes.Cloud Computing has emerged as a platform for individuals beside the corporate sector.It provides cost-effective infrastructure,platform and software services in a shared environment.On the other hand,the emergence of industry 4.0 brought new challenges for the adaptability and infusion of cloud computing.As the global work environment is adapting constituents of industry 4.0 in terms of robotics,artificial intelligence and IoT devices,it is becoming eminent that one emerging challenge is collaborative schematics.Provision of such autonomous mechanism that can develop,manage and operationalize digital resources like CoBots to perform tasks in a distributed and collaborative cloud environment for optimized utilization of resources,ensuring schedule completion.Collaborative schematics are also linked with Bigdata management produced by large scale industry 4.0 setups.Different use cases and simulation results showed a significant improvement in Pod CPU utilization,latency,and throughput over Kubernetes environment.展开更多
Containerization is a fundamental component of modern cloud-native infrastructure,and Kubernetes is a prominent platform of container orchestration systems.However,containerization raises significant security concerns...Containerization is a fundamental component of modern cloud-native infrastructure,and Kubernetes is a prominent platform of container orchestration systems.However,containerization raises significant security concerns due to the nature of sharing a kernel among multiple containers,which can lead to container breakout or privilege escalation.Kubernetes cannot avoid it as well.While various tools,such as container image scanning and configuration checking,can mitigate container workload vulnerabilities,these are not foolproof and cannot guarantee perfect isolation or prevent every active threat in runtime.As such,a policy enforcement solution is required to tackle the problem,and existing solutions based on LSM(Linux Security Module)frameworks may not be adequate for some situations.To address this,we propose an enforcement system based on BPF-LSM,which leverages eBPF(extended Berkeley Packet Filter)technology to provide fine-grained control and dynamic adoption of security policies.In this paper,we compare different LSM implementations to highlight the challenges of current enforcement solutions before detailing the design of our eBPF-based Kubernetes Runtime Instrumentation and Enforcement System(KRSIE).Finally,we evaluate the effectiveness of our system using a real-world scenario,as measuring the performance of a policy enforcement system is a complex task.Our results show that KRSIE can successfully control containers’behaviors using LSM hooks at container runtime,offering improved container security for cloud-native infrastructure.展开更多
In a cloud-native era,the Kubernetes-based workflow engine enables workflow containerized execution through the inherent abilities of Kubernetes.However,when encountering continuous workflow requests and unexpected re...In a cloud-native era,the Kubernetes-based workflow engine enables workflow containerized execution through the inherent abilities of Kubernetes.However,when encountering continuous workflow requests and unexpected resource request spikes,the engine is limited to the current workflow load information for resource allocation,which lacks the agility and predictability of resource allocation,resulting in over and underprovisioning resources.This mechanism seriously hinders workflow execution efficiency and leads to high resource waste.To overcome these drawbacks,we propose an adaptive resource allocation scheme named adaptive resource allocation scheme(ARAS)for the Kubernetes-based workflow engines.Considering potential future workflow task requests within the current task pod’s lifecycle,the ARAS uses a resource scaling strategy to allocate resources in response to high-concurrency workflow scenarios.The ARAS offers resource discovery,resource evaluation,and allocation functionalities and serves as a key component for our tailored workflow engine(KubeAdaptor).By integrating the ARAS into KubeAdaptor for workflow containerized execution,we demonstrate the practical abilities of KubeAdaptor and the advantages of our ARAS.Compared with the baseline algorithm,experimental evaluation under three distinct workflow arrival patterns shows that ARAS gains time-saving of 9.8% to 40.92% in the average total duration of all workflows,time-saving of 26.4% to 79.86% in the average duration of individual workflow,and an increase of 1% to 16% in centrol processing unit(CPU)and memory resource usage rate.展开更多
Nomadic Vehicular Cloud(NVC)is envisaged in this work.The predo-minant aspects of NVC is,it moves along with the vehicle that initiates it and functions only with the resources of moving vehicles on the heavy traffic ...Nomadic Vehicular Cloud(NVC)is envisaged in this work.The predo-minant aspects of NVC is,it moves along with the vehicle that initiates it and functions only with the resources of moving vehicles on the heavy traffic road without relying on any of the static infrastructure and NVC decides the initiation time of container migration using cell transmission model(CTM).Containers are used in the place of Virtual Machines(VM),as containers’features are very apt to NVC’s dynamic environment.The specifications of 5G NR V2X PC5 interface are applied to NVC,for the feature of not relying on the network coverage.Nowa-days,the peak traffic on the road and the bottlenecks due to it are inevitable,which are seen here as the benefits for VC in terms of resource availability and residual in-network time.The speed range of high-end vehicles poses the issue of dis-connectivity among VC participants,that results the container migration failure.As the entire VC participants are on the move,to maintain proximity of the containers hosted by them,estimating their movements plays a vital role.To infer the vehicle movements on the road stretch and initiate the container migration prior enough to avoid the migration failure due to vehicles dynamicity,this paper proposes to apply the CTM to the container based and 5G NR V2X enabled NVC.The simulation results show that there is a significant increase in the success rate of vehicular cloud in terms of successful container migrations.展开更多
Based on the principle of asexual reproduction,a kind of scale breeding and reproduction technique of Ficus tikoua Bur.container seedlings was explored by using the characteristics of strong adaptability to the enviro...Based on the principle of asexual reproduction,a kind of scale breeding and reproduction technique of Ficus tikoua Bur.container seedlings was explored by using the characteristics of strong adaptability to the environment and fast growth and reproduction.Using non-woven bag as a breeding container for seedlings,the scale breeding and reproduction technique of F.tikoua container seedlings was summarized through the important links of seedling bed construction,seedling collection,soil configuration,container selection,cutting cultivation,field management,and disease and pest control.This technique can achieve differential,massive and sustainable efficient breeding and reproduction of F.tikoua seedlings in a short time.展开更多
Cloud computing plays an important role in today’s Internet environment,which meets the requirements of scalability,security and reliability by using virtualization technologies.Container technology is one of the two...Cloud computing plays an important role in today’s Internet environment,which meets the requirements of scalability,security and reliability by using virtualization technologies.Container technology is one of the two mainstream virtualization solutions.Its lightweight,high deployment efficiency make container technology widely used in large-scale cloud computing.While container technology has created huge benefits for cloud service providers and tenants,it cannot meet the requirements of security monitoring and management from a tenant perspective.Currently,tenants can only run their security monitors in the target container,but it is not secure because the attacker is able to detect and compromise the security monitor.In this paper,a secure external monitoring approach is proposed to monitor target containers in another management container.The management container is transparent for target containers,but it can obtain the executing information of target containers,providing a secure monitoring environment.Security monitors running inside management containers are secure for the cloud host,since the management containers are not privileged.We implement the transparent external management containers by performing the one-way isolation of processes and files.For process one-way isolation,we leverage Linux namespace technology to let management container become the parent of target containers.By mounting the file system of target container to that of the management container,file system one-way isolation is achieved.Compared with the existing host-based monitoring approach,our approach is more secure and suitable in the cloud environment.展开更多
From the perspective of logistics, the article discusses some essential functions and service functions of railway container freight stations. Then it plans the construction of the logistics operation system of contai...From the perspective of logistics, the article discusses some essential functions and service functions of railway container freight stations. Then it plans the construction of the logistics operation system of container freight stations, and designs five main operating yards such as deconsolidation and groupage .yard, storage and distribution yard, container receiving-departure yard, container stack yard, and special cargo yard. The management pattern is discussed under the direction of modern business management theory. The ideas presented in this article is significant to the construction of railway container freight stations.展开更多
The teaching design is based on the task of "Container Transport" in the course of"English for International Shipping Business", aiming to discuss Design of information teaching in Business English...The teaching design is based on the task of "Container Transport" in the course of"English for International Shipping Business", aiming to discuss Design of information teaching in Business English Class. MOSO TEACH, CFNET platform,Cartoon have been applied in the design. Informationalized teaching has brought the vividness and dramatic effect to the knowledgebased class.展开更多
The uninterrupted operation of the quay crane(QC)ensures that the large container ship can depart port within laytime,which effectively reduces the handling cost for the container terminal and ship owners.The QC waiti...The uninterrupted operation of the quay crane(QC)ensures that the large container ship can depart port within laytime,which effectively reduces the handling cost for the container terminal and ship owners.The QC waiting caused by automated guided vehicles(AGVs)delay in the uncertain environment can be alleviated by dynamic scheduling optimization.A dynamic scheduling process is introduced in this paper to solve the AGV scheduling and path planning problems,in which the scheduling scheme determines the starting and ending nodes of paths,and the choice of paths between nodes affects the scheduling of subsequent AGVs.This work proposes a two-stage mixed integer optimization model to minimize the transportation cost of AGVs under the constraint of laytime.A dynamic optimization algorithm,including the improved rule-based heuristic algorithm and the integration of the Dijkstra algorithm and the Q-Learning algorithm,is designed to solve the optimal AGV scheduling and path schemes.A new conflict avoidance strategy based on graph theory is also proposed to reduce the probability of path conflicts between AGVs.Numerical experiments are conducted to demonstrate the effectiveness of the proposed model and algorithm over existing methods.展开更多
Seedling quality is important for subtropical tree species endangered by the degradation of natural habitats in southern China.At present,the cultural regime for raising these seedlings involving fertilizer levels and...Seedling quality is important for subtropical tree species endangered by the degradation of natural habitats in southern China.At present,the cultural regime for raising these seedlings involving fertilizer levels and size of container is not clear.In this study,seedlings of three endangered species,red-seed tree(Ormosia hosiei),Zhejiang phoebe(Phoebe chekian gensis),and Zhejiang camphor(Cinnamomum japonicum)were evaluated along with red-bark oak(Cyclobalanopsis gilva)as a reference,a species which is not endangered.Seedlings were raised in 2.8,3.6,5.1,and 6.3 L containers and fertilizer applied at 1.0,2.0,3.0 and 4.0 kg m-3.Seedling height and leaf biomass increased in response to higher fertilizer levels while larger containers resulted in greater stem and root biomass.Root biomass of endangered species seedlings did not respond to neither treatments.Zhejiang phoebe seedlings responded to nitrogen and phosphorus uptake but red-seed tree seedlings were unaffected by any nutrient levels.Red-bark oak seedlings had high nitrogen-use efficiency.Based on the results,it is recommended using at least 5.1 L containers to culture Zhejiang phoebe and Zhejiang camphor seedlings with fertilizer at 3.0 kg m-3.Red-bark oak and red-seed tree seedlings should be cultured with 2.0 kg m-3 in smaller containers.展开更多
Smart containers have been extensively applied in the maritime industry by embracing the Internet of Things to realize container status monitoring and data offloading without human intervention.However, the offloading...Smart containers have been extensively applied in the maritime industry by embracing the Internet of Things to realize container status monitoring and data offloading without human intervention.However, the offloading rate and delay in the offshore region are limited by the coverage of the onshore base station(BS). In this paper, we investigate the unmanned aerial vehicle(UAV)-assisted data offloading for smart containers in offshore maritime communications where the UAV is as a relay node between smart containers and onshore BS. We first consider the mobility of container vessel in the offshore region and establish a UAV-assisted data offloading model. Based on this model, a data offloading algorithm is proposed to reduce the average offloading delay under data-size requirements and available energy constraints of smart containers. Specifically, the convex-concave procedure is used to update time-slot assignment,offloading approach selection, and power allocation in an iterative manner. Simulation results show that the proposed algorithm can efficiently reduce average offloading delay and increase offloading success ratio.Moreover, it is shown that the UAV relay cannot always bring the performance gain on offloading delay especially in the close-to-shore area, which could give an insight on the deployment of UAV relay in offshore communications.展开更多
Container virtual technology aims to provide program independence and resource sharing.The container enables flexible cloud service.Compared with traditional virtualization,traditional virtual machines have difficulty...Container virtual technology aims to provide program independence and resource sharing.The container enables flexible cloud service.Compared with traditional virtualization,traditional virtual machines have difficulty in resource and expense requirements.The container technology has the advantages of smaller size,faster migration,lower resource overhead,and higher utilization.Within container-based cloud environment,services can adopt multi-target nodes.This paper reports research results to improve the traditional trust model with consideration of cooperation effects.Cooperation trust means that in a container-based cloud environment,services can be divided into multiple containers for different container nodes.When multiple target nodes work for one service at the same time,these nodes are in a cooperation state.When multi-target nodes cooperate to complete the service,the target nodes evaluate each other.The calculation of cooperation trust evaluation is used to update the degree of comprehensive trust.Experimental simulation results show that the cooperation trust evaluation can help solving the trust problem in the container-based cloud environment and can improve the success rate of following cooperation.展开更多
To evaluate the dynamic behavior of a container crane under seismic loads accurately,the contact state between the wheels and the rails or the ground that significantly affect the seismic response of the structure mus...To evaluate the dynamic behavior of a container crane under seismic loads accurately,the contact state between the wheels and the rails or the ground that significantly affect the seismic response of the structure must be considered elaborately.This paper has proposed a modeling method based on the theory of contact and friction for simulating the nonlinear seismic response of large and flexible structure of a jumbo movable container crane,including the contact problem regarding the wheels attached to the bottom of its legs and the rails on which they ride.These models are used to perform extensive dynamic time-history analysis in order to find out their nonlinear dynamic behavior under various excitation modes.It is found that the presented numerical modeling method simulates the nonlinear seismic response of a container crane quite well.Notably,it can verify and expand our understanding of the seismic behaviors by evaluating response performance for the large seaport cranes.展开更多
Jeep problem is a kind of model of logistics in extreme situation, which has application in exploration and aircraft problems. The optimal distance and driving strategy of multiple jeeps problem are known. We consider...Jeep problem is a kind of model of logistics in extreme situation, which has application in exploration and aircraft problems. The optimal distance and driving strategy of multiple jeeps problem are known. We consider multiple jeeps problem with container restriction, which is more complicated in the proof of feasibility and optimality of a driving strategy. We investigate when it can achieve the same optimal distance as without restriction.Based on the non-restricted optimal distance, a new driving strategy is proposed. We provide the necessary and sufficient condition to ensure the feasibility of the strategy, and obtain the maximal feasible distance.展开更多
基金National Natural Science Foundation of China(62073212).
文摘Improving the cooperative scheduling efficiency of equipment is the key for automated container terminals to copewith the development trend of large-scale ships. In order to improve the solution efficiency of the existing spacetimenetwork (STN) model for the cooperative scheduling problem of yard cranes (YCs) and automated guidedvehicles (AGVs) and extend its application scenarios, two improved STN models are proposed. The flow balanceconstraints in the original model are decomposed, and the trajectory constraints of YCs and AGVs are added toacquire the model STN_A. The coupling constraint in STN_A is updated, and buffer constraints are added toSTN_A so that themodel STN_B is built.As the size of the problem increases, the solution speed of CPLEX becomesthe bottleneck. So a heuristic method containing three groups of heuristic rules is designed to obtain a near-optimalsolution quickly. Experimental results showthat the computation time of STN_A is shortened by 49.47% on averageand the gap is reduced by 1.69% on average compared with the original model. The gap between the solution ofthe heuristic rules and the solution of CPLEX is less than 3.50%, and the solution time of the heuristic rules is onaverage 99.85% less than the solution time of CPLEX. Compared with STN_A, the computation time for solvingSTN_B increases by 58.93% on average.
基金This research was supported in part by the National Key Research and Development Program of China under Grant 2022YFB3305303in part by the National Natural Science Foundations of China(NSFC)under Grant 62106055+1 种基金in part by the Guangdong Natural Science Foundation under Grant 2022A1515011825in part by the Guangzhou Science and Technology Planning Project under Grants 2023A04J0388 and 2023A03J0662.
文摘Marine container terminal(MCT)plays a key role in the marine intelligent transportation system and international logistics system.However,the efficiency of resource scheduling significantly influences the operation performance of MCT.To solve the practical resource scheduling problem(RSP)in MCT efficiently,this paper has contributions to both the problem model and the algorithm design.Firstly,in the problem model,different from most of the existing studies that only consider scheduling part of the resources in MCT,we propose a unified mathematical model for formulating an integrated RSP.The new integrated RSP model allocates and schedules multiple MCT resources simultaneously by taking the total cost minimization as the objective.Secondly,in the algorithm design,a pre-selection-based ant colony system(PACS)approach is proposed based on graphic structure solution representation and a pre-selection strategy.On the one hand,as the RSP can be formulated as the shortest path problem on the directed complete graph,the graphic structure is proposed to represent the solution encoding to consider multiple constraints and multiple factors of the RSP,which effectively avoids the generation of infeasible solutions.On the other hand,the pre-selection strategy aims to reduce the computational burden of PACS and to fast obtain a higher-quality solution.To evaluate the performance of the proposed novel PACS in solving the new integrated RSP model,a set of test cases with different sizes is conducted.Experimental results and comparisons show the effectiveness and efficiency of the PACS algorithm,which can significantly outperform other state-of-the-art algorithms.
基金supported in part by the National Natural Science Foundation of China under Grant 62071070.
文摘Internet of Vehicles(IoV)applications integrating with edge com-puting will significantly drive the growth of IoV.However,the contradiction between the high-speed mobility of vehicles,the delay sensitivity of corre-sponding IoV applications and the limited coverage and resource capacity of distributed edge servers will pose challenges to the service continuity and stability of IoV applications.IoV application migration is a promising solution that can be supported by application containerization,a technology for seamless cross-edge-server application migration without user perception.Therefore,this paper proposes the container-based IoV edge application migration mechanism,consisting of three parts.The first is the migration trigger determination algorithm for cross-border migration and service degra-dation migration,respectively,based on trajectory prediction and traffic awareness to improve the determination accuracy.The second is the migration target decision calculation model for minimizing the average migration time and maximizing the average service time to reduce migration times and improve the stability and adaptability of migration decisions.The third is the migration decision algorithm based on the improved artificial bee colony algorithm to avoid local optimal migration decisions.Simulation results show that the proposed migration mechanism can reduce migration times,reduce average migration time,improve average service time and enhance the stability and adaptability of IoV application services.
基金supported by the National Natural Science Foundation of China(51971040,52171101)the Natural Science Foundation of Chongqing(cstc2021jcyj-msxmX0613)+1 种基金the National Natural Science Foundation of China(52001036,51971044)the Independent Research Project of State Key Laboratory of Mechanical Transmissions(SKLMT-ZZKT-2022M12).
文摘Coating technologies are a commonly used way to protect metals against corrosion.However,with more and more severe service environments of materials,many protective coating systems often are not environmentally friendly or toxic as in the case of chromates.Based on the world’s abundant ideal magnesium(Mg)and its alloy,the smart self-healing anticorrosive coating can autonomously restore the damaged part of the coating according to the environmental changes,strengthen the corrosion protection ability,and prolong its service life.This paper reviews the research progress of smart self-healing coatings on Mg alloys.These coatings mostly contain suitable corrosion inhibitors encapsulated into micro/nano containers.Moreover,the different self-healing mechanisms and functionalities of micro/nano containers are discussed.The micro/nano containers range from inorganic nanocontainers such as mesoporous nanoparticles(silica(SiO_(2)),titanium dioxide(TiO_(2)),etc.),over inorganic clays(halloysite,hydrotalcite-like,zeolite),to organic nanocontainers such as polymer microcapsules,nanofibers,chitosan(CS)and cyclodextrin(CD),as well as,carbon materials such as graphene and carbon nanotubes and hybrids such as metal organic frameworks.The functioning of micro/nano containers can be divided in two principal groups:autonomous(based on defect filling and corrosion inhibition)and non-autonomous(based on dynamic bonds and shape memory polymers).Moreover,multi functionalities and composite applications of various micro/nano containers are summarized.At present,significant progress has been made in the preparation methods and technologies of micro/nano containers.Achieving long-term self-healing properties of coatings sensing of coating failure and early warning after self-healing function failure can be expected as the main development direction of self-healing corrosion protection coatings in the future.
基金Project supported by the National Natural Science Foundation of China(Nos.51978336 and11702117)。
文摘A nonlinear semi-analytical scheme is proposed for investigating the finiteamplitude nonlinear sloshing in a horizontally baffled rectangular liquid container under the seismic excitation.The sub-domain method is developed to analytically derive the modal behaviors of the baffled linear sloshing.The viscosity dissipation effects from the interior liquid and boundary layers are considered.With the introduction of the generalized time-dependent coordinates,the surface wave elevation and velocity potential are represented by a series of linear modal eigenfunctions.The infinite-dimensional modal system of the nonlinear sloshing is formulated based on the Bateman-Luke variational principle,which is further reduced to the finite-dimensional modal system by using the NarimanovMoiseev asymptotic ordering.The base force and overturning moment induced by the nonlinear sloshing are derived as the functions of the generalized time-dependent coordinates.The present results match well with the available analytical,numerical,and experimental results.The paper examines the surface wave elevation,base force,and overturning moment versus the baffle parameters and excitation amplitude in detail.
文摘Kubernetes is an open-source container management tool which automates container deployment,container load balancing and container(de)scaling,including Horizontal Pod Autoscaler(HPA),Vertical Pod Autoscaler(VPA).HPA enables flawless operation,interactively scaling the number of resource units,or pods,without downtime.Default Resource Metrics,such as CPU and memory use of host machines and pods,are monitored by Kubernetes.Cloud Computing has emerged as a platform for individuals beside the corporate sector.It provides cost-effective infrastructure,platform and software services in a shared environment.On the other hand,the emergence of industry 4.0 brought new challenges for the adaptability and infusion of cloud computing.As the global work environment is adapting constituents of industry 4.0 in terms of robotics,artificial intelligence and IoT devices,it is becoming eminent that one emerging challenge is collaborative schematics.Provision of such autonomous mechanism that can develop,manage and operationalize digital resources like CoBots to perform tasks in a distributed and collaborative cloud environment for optimized utilization of resources,ensuring schedule completion.Collaborative schematics are also linked with Bigdata management produced by large scale industry 4.0 setups.Different use cases and simulation results showed a significant improvement in Pod CPU utilization,latency,and throughput over Kubernetes environment.
基金supported by the Institute of Information&Communications Technology Planning&Evaluation (IITP)grant funded by the Korea Government (MSIT), (No.2020-0-00952,Development of 5G edge security technology for ensuring 5G+service stability and availability,50%)the Institute of Information and Communications Technology Planning and Evaluation (IITP)grant funded by the MSIT (Ministry of Science and ICT),Korea (No.IITP-2023-2020-0-01602,ITRC (Information Technology Research Center)support program,50%).
文摘Containerization is a fundamental component of modern cloud-native infrastructure,and Kubernetes is a prominent platform of container orchestration systems.However,containerization raises significant security concerns due to the nature of sharing a kernel among multiple containers,which can lead to container breakout or privilege escalation.Kubernetes cannot avoid it as well.While various tools,such as container image scanning and configuration checking,can mitigate container workload vulnerabilities,these are not foolproof and cannot guarantee perfect isolation or prevent every active threat in runtime.As such,a policy enforcement solution is required to tackle the problem,and existing solutions based on LSM(Linux Security Module)frameworks may not be adequate for some situations.To address this,we propose an enforcement system based on BPF-LSM,which leverages eBPF(extended Berkeley Packet Filter)technology to provide fine-grained control and dynamic adoption of security policies.In this paper,we compare different LSM implementations to highlight the challenges of current enforcement solutions before detailing the design of our eBPF-based Kubernetes Runtime Instrumentation and Enforcement System(KRSIE).Finally,we evaluate the effectiveness of our system using a real-world scenario,as measuring the performance of a policy enforcement system is a complex task.Our results show that KRSIE can successfully control containers’behaviors using LSM hooks at container runtime,offering improved container security for cloud-native infrastructure.
基金supported by the National Natural Science Foundation of China(61873030,62002019).
文摘In a cloud-native era,the Kubernetes-based workflow engine enables workflow containerized execution through the inherent abilities of Kubernetes.However,when encountering continuous workflow requests and unexpected resource request spikes,the engine is limited to the current workflow load information for resource allocation,which lacks the agility and predictability of resource allocation,resulting in over and underprovisioning resources.This mechanism seriously hinders workflow execution efficiency and leads to high resource waste.To overcome these drawbacks,we propose an adaptive resource allocation scheme named adaptive resource allocation scheme(ARAS)for the Kubernetes-based workflow engines.Considering potential future workflow task requests within the current task pod’s lifecycle,the ARAS uses a resource scaling strategy to allocate resources in response to high-concurrency workflow scenarios.The ARAS offers resource discovery,resource evaluation,and allocation functionalities and serves as a key component for our tailored workflow engine(KubeAdaptor).By integrating the ARAS into KubeAdaptor for workflow containerized execution,we demonstrate the practical abilities of KubeAdaptor and the advantages of our ARAS.Compared with the baseline algorithm,experimental evaluation under three distinct workflow arrival patterns shows that ARAS gains time-saving of 9.8% to 40.92% in the average total duration of all workflows,time-saving of 26.4% to 79.86% in the average duration of individual workflow,and an increase of 1% to 16% in centrol processing unit(CPU)and memory resource usage rate.
文摘Nomadic Vehicular Cloud(NVC)is envisaged in this work.The predo-minant aspects of NVC is,it moves along with the vehicle that initiates it and functions only with the resources of moving vehicles on the heavy traffic road without relying on any of the static infrastructure and NVC decides the initiation time of container migration using cell transmission model(CTM).Containers are used in the place of Virtual Machines(VM),as containers’features are very apt to NVC’s dynamic environment.The specifications of 5G NR V2X PC5 interface are applied to NVC,for the feature of not relying on the network coverage.Nowa-days,the peak traffic on the road and the bottlenecks due to it are inevitable,which are seen here as the benefits for VC in terms of resource availability and residual in-network time.The speed range of high-end vehicles poses the issue of dis-connectivity among VC participants,that results the container migration failure.As the entire VC participants are on the move,to maintain proximity of the containers hosted by them,estimating their movements plays a vital role.To infer the vehicle movements on the road stretch and initiate the container migration prior enough to avoid the migration failure due to vehicles dynamicity,this paper proposes to apply the CTM to the container based and 5G NR V2X enabled NVC.The simulation results show that there is a significant increase in the success rate of vehicular cloud in terms of successful container migrations.
基金Supported by National Natural Science Foundation of China(32160086,32160287,31900271)Key Project of Guizhou Provincial Science and Technology Fund(QKHJC[2019]1455)+1 种基金Central Government Supporting Local Science and Technology Development Fund Project(QKZYD[2021]4010)Undergraduate Innovation and Entrepreneurship Training Program(S202110665031,S202310665002,S202310665012).
文摘Based on the principle of asexual reproduction,a kind of scale breeding and reproduction technique of Ficus tikoua Bur.container seedlings was explored by using the characteristics of strong adaptability to the environment and fast growth and reproduction.Using non-woven bag as a breeding container for seedlings,the scale breeding and reproduction technique of F.tikoua container seedlings was summarized through the important links of seedling bed construction,seedling collection,soil configuration,container selection,cutting cultivation,field management,and disease and pest control.This technique can achieve differential,massive and sustainable efficient breeding and reproduction of F.tikoua seedlings in a short time.
基金This paper is supported by National Natural Science Foundation of China(http://www.nsfc.gov.cn/)under Grant No.61872111,and Sichuan Science and Technology Program(http://kjt.sc.gov.cn/)under Grant No.2019YFSY0049 which are both received by L.Ye.
文摘Cloud computing plays an important role in today’s Internet environment,which meets the requirements of scalability,security and reliability by using virtualization technologies.Container technology is one of the two mainstream virtualization solutions.Its lightweight,high deployment efficiency make container technology widely used in large-scale cloud computing.While container technology has created huge benefits for cloud service providers and tenants,it cannot meet the requirements of security monitoring and management from a tenant perspective.Currently,tenants can only run their security monitors in the target container,but it is not secure because the attacker is able to detect and compromise the security monitor.In this paper,a secure external monitoring approach is proposed to monitor target containers in another management container.The management container is transparent for target containers,but it can obtain the executing information of target containers,providing a secure monitoring environment.Security monitors running inside management containers are secure for the cloud host,since the management containers are not privileged.We implement the transparent external management containers by performing the one-way isolation of processes and files.For process one-way isolation,we leverage Linux namespace technology to let management container become the parent of target containers.By mounting the file system of target container to that of the management container,file system one-way isolation is achieved.Compared with the existing host-based monitoring approach,our approach is more secure and suitable in the cloud environment.
文摘From the perspective of logistics, the article discusses some essential functions and service functions of railway container freight stations. Then it plans the construction of the logistics operation system of container freight stations, and designs five main operating yards such as deconsolidation and groupage .yard, storage and distribution yard, container receiving-departure yard, container stack yard, and special cargo yard. The management pattern is discussed under the direction of modern business management theory. The ideas presented in this article is significant to the construction of railway container freight stations.
文摘The teaching design is based on the task of "Container Transport" in the course of"English for International Shipping Business", aiming to discuss Design of information teaching in Business English Class. MOSO TEACH, CFNET platform,Cartoon have been applied in the design. Informationalized teaching has brought the vividness and dramatic effect to the knowledgebased class.
基金supported in part by the National Natural Science Foundation of China(61473053)the Science and Technology Innovation Foundation of Dalian,China(2020JJ26GX033)。
文摘The uninterrupted operation of the quay crane(QC)ensures that the large container ship can depart port within laytime,which effectively reduces the handling cost for the container terminal and ship owners.The QC waiting caused by automated guided vehicles(AGVs)delay in the uncertain environment can be alleviated by dynamic scheduling optimization.A dynamic scheduling process is introduced in this paper to solve the AGV scheduling and path planning problems,in which the scheduling scheme determines the starting and ending nodes of paths,and the choice of paths between nodes affects the scheduling of subsequent AGVs.This work proposes a two-stage mixed integer optimization model to minimize the transportation cost of AGVs under the constraint of laytime.A dynamic optimization algorithm,including the improved rule-based heuristic algorithm and the integration of the Dijkstra algorithm and the Q-Learning algorithm,is designed to solve the optimal AGV scheduling and path schemes.A new conflict avoidance strategy based on graph theory is also proposed to reduce the probability of path conflicts between AGVs.Numerical experiments are conducted to demonstrate the effectiveness of the proposed model and algorithm over existing methods.
基金This work was supported by“Forestry Science and Technology Cooperation Project between Zhejiang Province and Chinese Academy of Forestry(2017SY19)”“Fundamental Research Funds of CAF”(CAFYBB2018GC003).
文摘Seedling quality is important for subtropical tree species endangered by the degradation of natural habitats in southern China.At present,the cultural regime for raising these seedlings involving fertilizer levels and size of container is not clear.In this study,seedlings of three endangered species,red-seed tree(Ormosia hosiei),Zhejiang phoebe(Phoebe chekian gensis),and Zhejiang camphor(Cinnamomum japonicum)were evaluated along with red-bark oak(Cyclobalanopsis gilva)as a reference,a species which is not endangered.Seedlings were raised in 2.8,3.6,5.1,and 6.3 L containers and fertilizer applied at 1.0,2.0,3.0 and 4.0 kg m-3.Seedling height and leaf biomass increased in response to higher fertilizer levels while larger containers resulted in greater stem and root biomass.Root biomass of endangered species seedlings did not respond to neither treatments.Zhejiang phoebe seedlings responded to nitrogen and phosphorus uptake but red-seed tree seedlings were unaffected by any nutrient levels.Red-bark oak seedlings had high nitrogen-use efficiency.Based on the results,it is recommended using at least 5.1 L containers to culture Zhejiang phoebe and Zhejiang camphor seedlings with fertilizer at 3.0 kg m-3.Red-bark oak and red-seed tree seedlings should be cultured with 2.0 kg m-3 in smaller containers.
基金supported in part by National Key Research and Development Program of China under Grant 2019YFE0111600in part by National Natural Science Foundation of China under Grants 62101089, 62002042, 61971083, and 51939001+4 种基金in part by China Postdoctoral Science Foundation under Grants 2021M700655 and 2021M690022in part by Cooperative Scientific Research Project, Chunhui Program of Ministry of Education, P. R. Chinain part by LiaoNing Revitalization Talents Program under Grant XLYC2002078in part by Dalian Science and Technology Innovation Fund under Grant 2019J11CY015in part by the Fundamental Research Funds for Central Universities under Grants 3132021237 and 3132021223。
文摘Smart containers have been extensively applied in the maritime industry by embracing the Internet of Things to realize container status monitoring and data offloading without human intervention.However, the offloading rate and delay in the offshore region are limited by the coverage of the onshore base station(BS). In this paper, we investigate the unmanned aerial vehicle(UAV)-assisted data offloading for smart containers in offshore maritime communications where the UAV is as a relay node between smart containers and onshore BS. We first consider the mobility of container vessel in the offshore region and establish a UAV-assisted data offloading model. Based on this model, a data offloading algorithm is proposed to reduce the average offloading delay under data-size requirements and available energy constraints of smart containers. Specifically, the convex-concave procedure is used to update time-slot assignment,offloading approach selection, and power allocation in an iterative manner. Simulation results show that the proposed algorithm can efficiently reduce average offloading delay and increase offloading success ratio.Moreover, it is shown that the UAV relay cannot always bring the performance gain on offloading delay especially in the close-to-shore area, which could give an insight on the deployment of UAV relay in offshore communications.
基金This research work was supported by the National Natural Science Foundation of China(Grant No.61762031)Guangxi Key Research and Development Plan(No.2017AB51024)Guangxi key Laboratory of Embedded Technology and Intelligent System,Guangxi Fundamental Laboratory for Embedded Technology and Intelligent Systems.
文摘Container virtual technology aims to provide program independence and resource sharing.The container enables flexible cloud service.Compared with traditional virtualization,traditional virtual machines have difficulty in resource and expense requirements.The container technology has the advantages of smaller size,faster migration,lower resource overhead,and higher utilization.Within container-based cloud environment,services can adopt multi-target nodes.This paper reports research results to improve the traditional trust model with consideration of cooperation effects.Cooperation trust means that in a container-based cloud environment,services can be divided into multiple containers for different container nodes.When multiple target nodes work for one service at the same time,these nodes are in a cooperation state.When multi-target nodes cooperate to complete the service,the target nodes evaluate each other.The calculation of cooperation trust evaluation is used to update the degree of comprehensive trust.Experimental simulation results show that the cooperation trust evaluation can help solving the trust problem in the container-based cloud environment and can improve the success rate of following cooperation.
基金National Natural Science Foundation of China(No.51275369)
文摘To evaluate the dynamic behavior of a container crane under seismic loads accurately,the contact state between the wheels and the rails or the ground that significantly affect the seismic response of the structure must be considered elaborately.This paper has proposed a modeling method based on the theory of contact and friction for simulating the nonlinear seismic response of large and flexible structure of a jumbo movable container crane,including the contact problem regarding the wheels attached to the bottom of its legs and the rails on which they ride.These models are used to perform extensive dynamic time-history analysis in order to find out their nonlinear dynamic behavior under various excitation modes.It is found that the presented numerical modeling method simulates the nonlinear seismic response of a container crane quite well.Notably,it can verify and expand our understanding of the seismic behaviors by evaluating response performance for the large seaport cranes.
基金supported by the Fundamental Research Funds for the Central Universities(WUT:2017 IVA 073)。
文摘Jeep problem is a kind of model of logistics in extreme situation, which has application in exploration and aircraft problems. The optimal distance and driving strategy of multiple jeeps problem are known. We consider multiple jeeps problem with container restriction, which is more complicated in the proof of feasibility and optimality of a driving strategy. We investigate when it can achieve the same optimal distance as without restriction.Based on the non-restricted optimal distance, a new driving strategy is proposed. We provide the necessary and sufficient condition to ensure the feasibility of the strategy, and obtain the maximal feasible distance.