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The hydrothermal wave of large-Prandtl-number fluid in a shallow cavity 被引量:3
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作者 TANG ZeMei & HU WenRui National Microgravity Laboratory,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100080,China 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2007年第6期787-796,共10页
The hydrothermal wave was investigated numerically for large-Prandtl-number fluid (Pr = 105.6) in a shallow cavity with different heated sidewalls. The traveling wave appears and propagates in the direction opposite t... The hydrothermal wave was investigated numerically for large-Prandtl-number fluid (Pr = 105.6) in a shallow cavity with different heated sidewalls. The traveling wave appears and propagates in the direction opposite to the surface flow (upstream) in the case of zero gravity when the applied temperature difference grows and over the critical value. The phase relationships of the disturbed velocity,temperature and pressure demonstrate that the traveling wave is driven by the disturbed tem-perature,which is named hydrothermal wave. The hydrothermal wave is so weak that the oscillatory flow field and temperature distribution can hardly be observed in the liquid layer. The exciting mechanism of hydrothermal wave is analyzed and discussed in the present paper. 展开更多
关键词 HYDROTHERMAL wave numerical simulation microgravity The HYDROTHERMAL WAVE was investigated numerically for large-Prandtl-number FLUID (Pr = 105.6) in a shallow cavity with different heated sidewalls. The TRAVELING WAVE appears and propagates in the direction opposite to the surface flow (upstream) in the case of zero gravity when the applied TEMPERATURE difference grows and over the critical value. The phase relationships of the disturbed velocity TEMPERATURE and pressure demonstrate that the TRAVELING WAVE IS driven by the disturbed temperature which IS named HYDROTHERMAL wave. The HYDROTHERMAL WAVE IS so weak that the oscillatory flow field and TEMPERATURE distribution can hardly be observed in the liquid layer. The exciting mechanism of HYDROTHERMAL WAVE IS analyzed and discussed in the present paper.
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Data Driven Vibration Control:A
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作者 Weiyi Yang Shuai Li Xin Luo 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2024年第9期1898-1917,共20页
With the ongoing advancements in sensor networks and data acquisition technologies across various systems like manufacturing,aviation,and healthcare,the data driven vibration control(DDVC)has attracted broad interests... With the ongoing advancements in sensor networks and data acquisition technologies across various systems like manufacturing,aviation,and healthcare,the data driven vibration control(DDVC)has attracted broad interests from both the industrial and academic communities.Input shaping(IS),as a simple and effective feedforward method,is greatly demanded in DDVC methods.It convolves the desired input command with impulse sequence without requiring parametric dynamics and the closed-loop system structure,thereby suppressing the residual vibration separately.Based on a thorough investigation into the state-of-the-art DDVC methods,this survey has made the following efforts:1)Introducing the IS theory and typical input shapers;2)Categorizing recent progress of DDVC methods;3)Summarizing commonly adopted metrics for DDVC;and 4)Discussing the engineering applications and future trends of DDVC.By doing so,this study provides a systematic and comprehensive overview of existing DDVC methods from designing to optimizing perspectives,aiming at promoting future research regarding this emerging and vital issue. 展开更多
关键词 Data driven vibration control(DDVC) data science designing method feedforward control industrial robot input shaping optimizing method residual vibration
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Formulation of Work-Study Combined and Result-Oriented Integrated Curriculum Standards
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作者 Lianfang LI Chunhua DU +2 位作者 Fen YANG Yun LI Yanfei NIU 《Medicinal Plant》 2024年第3期79-83,共5页
According to the Annex Technical Regulations for Integrated Curriculum Development(Trial)in Document No.30 of the General Office of the Ministry of Human Resources and Social Security(2012),this paper studies the form... According to the Annex Technical Regulations for Integrated Curriculum Development(Trial)in Document No.30 of the General Office of the Ministry of Human Resources and Social Security(2012),this paper studies the formulation of the curriculum standards for the integration of Chinese medicinal materials production.We focus on the formulation ideas of the curriculum standards for the integration of Chinese medicinal materials production,the formulation process of the curriculum standards for the integration of Chinese medicinal materials production,including the description of typical work tasks,the determination of curriculum objectives,the analysis of study content,the description of referential study tasks,teaching implementation suggestions,assessment and evaluation suggestions,which can provide a reference for the development and research of other related integrated courses. 展开更多
关键词 Integration of WORK and STUDY WORK process Curriculum STANDARDS Production of Chinese MEDICINAL materials Typical WORK taskS REFERENTIAL STUDY taskS
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渤海风驱-潮致拉格朗日余流的数值模拟与季相时空变异 被引量:17
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作者 李国胜 王海龙 李柏良 《地理研究》 CSCD 北大核心 2005年第3期359-370,共12页
利用HellermanandRosenstein全球风应力资料中的多年月平均风场资料驱动ECOM模型,设计了潮致、纯风生以及风与潮两者叠加三个数值实验对渤海海域风驱-潮致拉格朗日(Lagrange)余流的逐月时空分布与季节变化进行了模拟。研究结果表明,季... 利用HellermanandRosenstein全球风应力资料中的多年月平均风场资料驱动ECOM模型,设计了潮致、纯风生以及风与潮两者叠加三个数值实验对渤海海域风驱-潮致拉格朗日(Lagrange)余流的逐月时空分布与季节变化进行了模拟。研究结果表明,季风的大小和方向决定了渤海风驱-潮致拉格朗日余流的大小和方向,是影响余流流向和流速的重要因素。冬季,从渤海西岸到莱州湾海域风驱-潮致拉格朗日余流表现出一个大逆时针环流,辽东湾呈现顺时针方向流动,渤海中部存在一个弱的顺时针流环。夏季,整个渤海海域呈现顺时针流况,渤海海盆存在一微弱的逆时针涡旋,一支西南向流沿辽东湾东岸穿越渤海海盆,与起自渤海湾的东向流一起进入莱州湾。风驱-潮致拉格朗日余流主要受风的控制,潮汐则起到一定的调整作用。 展开更多
关键词 COM and 西
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Enhanced Hybrid Equilibrium Strategy in Fog-Cloud Computing Networks with Optimal Task Scheduling
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作者 Muchang Rao Hang Qin 《Computers, Materials & Continua》 SCIE EI 2024年第5期2647-2672,共26页
More devices in the Intelligent Internet of Things(AIoT)result in an increased number of tasks that require low latency and real-time responsiveness,leading to an increased demand for computational resources.Cloud com... More devices in the Intelligent Internet of Things(AIoT)result in an increased number of tasks that require low latency and real-time responsiveness,leading to an increased demand for computational resources.Cloud computing’s low-latency performance issues in AIoT scenarios have led researchers to explore fog computing as a complementary extension.However,the effective allocation of resources for task execution within fog environments,characterized by limitations and heterogeneity in computational resources,remains a formidable challenge.To tackle this challenge,in this study,we integrate fog computing and cloud computing.We begin by establishing a fog-cloud environment framework,followed by the formulation of a mathematical model for task scheduling.Lastly,we introduce an enhanced hybrid Equilibrium Optimizer(EHEO)tailored for AIoT task scheduling.The overarching objective is to decrease both the makespan and energy consumption of the fog-cloud system while accounting for task deadlines.The proposed EHEO method undergoes a thorough evaluation against multiple benchmark algorithms,encompassing metrics likemakespan,total energy consumption,success rate,and average waiting time.Comprehensive experimental results unequivocally demonstrate the superior performance of EHEO across all assessed metrics.Notably,in the most favorable conditions,EHEO significantly diminishes both the makespan and energy consumption by approximately 50%and 35.5%,respectively,compared to the secondbest performing approach,which affirms its efficacy in advancing the efficiency of AIoT task scheduling within fog-cloud networks. 展开更多
关键词 Artificial intelligence of things fog computing task scheduling equilibrium optimizer differential evaluation algorithm local search
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Object-oriented Battlefield Environment Simulation Process Object Model Based on Task-driven 被引量:2
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作者 Jie ZHU Xiong YOU +1 位作者 Qing XIA Hongjun ZHANG 《Journal of Geodesy and Geoinformation Science》 2019年第3期31-43,共13页
Battlefield environment simulation process is an important part of battlefield environment information support, which needs to be built around the task process. At present, the interoperability between battlefield env... Battlefield environment simulation process is an important part of battlefield environment information support, which needs to be built around the task process. At present, the interoperability between battlefield environment simulation system and command and control system is still imperfect, and the traditional simulation data model cannot meet war fighters’ high-efficient and accurate understanding and analysis on battlefield environment’s information. Therefore, a kind of task-orientated battlefield environment simulation process model needs to be construed to effectively analyze the key information demands of the command and control system. The structured characteristics of tasks and simulation process are analyzed, and the simulation process concept model is constructed with the method of object-orientated. The data model and formal syntax of GeoBML are analyzed, and the logical model of simulation process is constructed with formal language. The object data structure of simulation process is defined and the object model of simulation process which maps tasks is constructed. In the end, the battlefield environment simulation platform modules are designed and applied based on this model, verifying that the model can effectively express the real-time dynamic correlation between battlefield environment simulation data and operational tasks. 展开更多
关键词 BATTLEFIELD environment simulation GeoBML object-orientated task driven process modeling
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Changes in brain activation patterns according to cross-training effect in serial reaction time task An functional MRI study
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作者 Yong Hyun Kwon Jung Won Kwon Ji Won Park 《Neural Regeneration Research》 SCIE CAS CSCD 2013年第7期639-646,共8页
Cross-training is a phenomenon related to motor learning, where motor performance of the untrained limb shows improvement in strength and skill execution following unilateral training of the homologous contralateral l... Cross-training is a phenomenon related to motor learning, where motor performance of the untrained limb shows improvement in strength and skill execution following unilateral training of the homologous contralateral limb. We used functional MRI to investigate whether motor performance of the untrained limb could be improved using a serial reaction time task according to motor sequential learning of the trained limb, and whether these skill acquisitions led to changes in brain activation patterns. We recruited 20 right-handed healthy subjects, who were randomly allocated into training and control groups. The training group was trained in performance of a serial reaction time task using their non-dominant left hand, 40 minutes per day, for 10 days, over a period of 2 weeks. The control group did not receive training. Measurements of response time and percentile of response accuracy were performed twice during pre- and post-training, while brain functional MRI was scanned during performance of the serial reaction time task using the untrained right hand. In the training group, prominent changes in response time and percentile of response accuracy were observed in both the untrained right hand and the trained left hand between pre- and post-training. The control group showed no significant changes in the untrained hand between pre- and post-training. In the training group, the activated volume of the cortical areas related to motor function (i.e., primary motor cortex, premotor area, posterior parietal cortex) showed a gradual decrease, and enhanced cerebellar activation of the vermis and the newly activated ipsilateral dentate nucleus were observed during performance of the serial reaction time task using the untrained right hand, accompanied by the cross-motor learning effect. However, no significant changes were observed in the control group. Our findings indicate that motor skills learned over the 2-week training using the trained limb were transferred to the opposite homologous limb, and motor skill acquisition of the untrained limb led to changes in brain activation patterns in the cerebral cortex and cerebellum. 展开更多
关键词 neural regeneration neuroimaging cross-training effects motor skill learning cortical activation cerebellar activation serial reaction time task functional MRI response time response accuracy primary motor cortex dentate nucleus VERMIS grants-supported paper photographs-containingpaper NEUROREGENERATION
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Data-driven modeling on anisotropic mechanical behavior of brain tissue with internal pressure
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作者 Zhiyuan Tang Yu Wang +3 位作者 Khalil I.Elkhodary Zefeng Yu Shan Tang Dan Peng 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期55-65,共11页
Brain tissue is one of the softest parts of the human body,composed of white matter and grey matter.The mechanical behavior of the brain tissue plays an essential role in regulating brain morphology and brain function... Brain tissue is one of the softest parts of the human body,composed of white matter and grey matter.The mechanical behavior of the brain tissue plays an essential role in regulating brain morphology and brain function.Besides,traumatic brain injury(TBI)and various brain diseases are also greatly influenced by the brain's mechanical properties.Whether white matter or grey matter,brain tissue contains multiscale structures composed of neurons,glial cells,fibers,blood vessels,etc.,each with different mechanical properties.As such,brain tissue exhibits complex mechanical behavior,usually with strong nonlinearity,heterogeneity,and directional dependence.Building a constitutive law for multiscale brain tissue using traditional function-based approaches can be very challenging.Instead,this paper proposes a data-driven approach to establish the desired mechanical model of brain tissue.We focus on blood vessels with internal pressure embedded in a white or grey matter matrix material to demonstrate our approach.The matrix is described by an isotropic or anisotropic nonlinear elastic model.A representative unit cell(RUC)with blood vessels is built,which is used to generate the stress-strain data under different internal blood pressure and various proportional displacement loading paths.The generated stress-strain data is then used to train a mechanical law using artificial neural networks to predict the macroscopic mechanical response of brain tissue under different internal pressures.Finally,the trained material model is implemented into finite element software to predict the mechanical behavior of a whole brain under intracranial pressure and distributed body forces.Compared with a direct numerical simulation that employs a reference material model,our proposed approach greatly reduces the computational cost and improves modeling efficiency.The predictions made by our trained model demonstrate sufficient accuracy.Specifically,we find that the level of internal blood pressure can greatly influence stress distribution and determine the possible related damage behaviors. 展开更多
关键词 Data driven Constitutive law ANISOTROPY Brain tissue Internal pressure
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Dynamic Offloading and Scheduling Strategy for Telematics Tasks Based on Latency Minimization
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作者 Yu Zhou Yun Zhang +4 位作者 Guowei Li Hang Yang Wei Zhang Ting Lyu Yueqiang Xu 《Computers, Materials & Continua》 SCIE EI 2024年第8期1809-1829,共21页
In current research on task offloading and resource scheduling in vehicular networks,vehicles are commonly assumed to maintain constant speed or relatively stationary states,and the impact of speed variations on task ... In current research on task offloading and resource scheduling in vehicular networks,vehicles are commonly assumed to maintain constant speed or relatively stationary states,and the impact of speed variations on task offloading is often overlooked.It is frequently assumed that vehicles can be accurately modeled during actual motion processes.However,in vehicular dynamic environments,both the tasks generated by the vehicles and the vehicles’surroundings are constantly changing,making it difficult to achieve real-time modeling for actual dynamic vehicular network scenarios.Taking into account the actual dynamic vehicular scenarios,this paper considers the real-time non-uniform movement of vehicles and proposes a vehicular task dynamic offloading and scheduling algorithm for single-task multi-vehicle vehicular network scenarios,attempting to solve the dynamic decision-making problem in task offloading process.The optimization objective is to minimize the average task completion time,which is formulated as a multi-constrained non-linear programming problem.Due to the mobility of vehicles,a constraint model is applied in the decision-making process to dynamically determine whether the communication range is sufficient for task offloading and transmission.Finally,the proposed vehicular task dynamic offloading and scheduling algorithm based on muti-agent deep deterministic policy gradient(MADDPG)is applied to solve the optimal solution of the optimization problem.Simulation results show that the algorithm proposed in this paper is able to achieve lower latency task computation offloading.Meanwhile,the average task completion time of the proposed algorithm in this paper can be improved by 7.6%compared to the performance of the MADDPG scheme and 51.1%compared to the performance of deep deterministic policy gradient(DDPG). 展开更多
关键词 Component vehicular DYNAMIC task offloading resource scheduling
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Distributed tasks-platforms scheduling method to holonic-C2 organization 被引量:3
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作者 WANG Xun YAO Peiyang +2 位作者 ZHANG Jieyong WAN Lujun JIA Fangchao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第1期110-120,共11页
To solve the problem of distributed tasks-platforms scheduling in holonic command and control(C2) organization,the basic elements of the organization are analyzed firstly and the formal description of organizational e... To solve the problem of distributed tasks-platforms scheduling in holonic command and control(C2) organization,the basic elements of the organization are analyzed firstly and the formal description of organizational elements and structure is provided. Based on the improvement of task execution quality,a single task resource scheduling model is established and the solving method based on the m-best algorithm is proposed. For the problem of tactical decision-holon cannot handle tasks with low priority effectively, a distributed resource scheduling collaboration mechanism based on platform pricing and a platform exchange mechanism based on resource capacities are designed. Finally,a series of experiments are designed to prove the effectiveness of these methods. The results show that the proposed distributed scheduling methods can realize the effective balance of platform resources. 展开更多
关键词 COMMAND and control (C2) decision-holon distributed task allocation task EXECUTION quality platform PRICE order optimization.
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Mobile Crowdsourcing Task Allocation Based on Dynamic Self-Attention GANs
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作者 Kai Wei Song Yu Qingxian Pan 《Computers, Materials & Continua》 SCIE EI 2024年第4期607-622,共16页
Crowdsourcing technology is widely recognized for its effectiveness in task scheduling and resource allocation.While traditional methods for task allocation can help reduce costs and improve efficiency,they may encoun... Crowdsourcing technology is widely recognized for its effectiveness in task scheduling and resource allocation.While traditional methods for task allocation can help reduce costs and improve efficiency,they may encounter challenges when dealing with abnormal data flow nodes,leading to decreased allocation accuracy and efficiency.To address these issues,this study proposes a novel two-part invalid detection task allocation framework.In the first step,an anomaly detection model is developed using a dynamic self-attentive GAN to identify anomalous data.Compared to the baseline method,the model achieves an approximately 4%increase in the F1 value on the public dataset.In the second step of the framework,task allocation modeling is performed using a twopart graph matching method.This phase introduces a P-queue KM algorithm that implements a more efficient optimization strategy.The allocation efficiency is improved by approximately 23.83%compared to the baseline method.Empirical results confirm the effectiveness of the proposed framework in detecting abnormal data nodes,enhancing allocation precision,and achieving efficient allocation. 展开更多
关键词 Mobile crowdsourcing task allocation anomaly detection GAN attention mechanisms
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Two-Stage IoT Computational Task Offloading Decision-Making in MEC with Request Holding and Dynamic Eviction
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作者 Dayong Wang Kamalrulnizam Bin Abu Bakar Babangida Isyaku 《Computers, Materials & Continua》 SCIE EI 2024年第8期2065-2080,共16页
The rapid development of Internet of Things(IoT)technology has led to a significant increase in the computational task load of Terminal Devices(TDs).TDs reduce response latency and energy consumption with the support ... The rapid development of Internet of Things(IoT)technology has led to a significant increase in the computational task load of Terminal Devices(TDs).TDs reduce response latency and energy consumption with the support of task-offloading in Multi-access Edge Computing(MEC).However,existing task-offloading optimization methods typically assume that MEC’s computing resources are unlimited,and there is a lack of research on the optimization of task-offloading when MEC resources are exhausted.In addition,existing solutions only decide whether to accept the offloaded task request based on the single decision result of the current time slot,but lack support for multiple retry in subsequent time slots.It is resulting in TD missing potential offloading opportunities in the future.To fill this gap,we propose a Two-Stage Offloading Decision-making Framework(TSODF)with request holding and dynamic eviction.Long Short-Term Memory(LSTM)-based task-offloading request prediction and MEC resource release estimation are integrated to infer the probability of a request being accepted in the subsequent time slot.The framework learns optimized decision-making experiences continuously to increase the success rate of task offloading based on deep learning technology.Simulation results show that TSODF reduces total TD’s energy consumption and delay for task execution and improves task offloading rate and system resource utilization compared to the benchmark method. 展开更多
关键词 Decision making internet of things load prediction task offloading multi-access edge computing
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农村通信,走好“过渡期”
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作者 杜燕鹏 孙忠营 《中国电信业》 2005年第5期17-21,共5页
在刚结束不久的“两会”上,“三农”问题再次成为被关注的焦点,其中农业通信、农业信息化等问题成为代表们探讨的热点话题。虽然我们不愿意看到,但是不可否认的是,目前农村通信状况普遍落后,农村与城市之间的“数字鸿沟”也越拉越大。... 在刚结束不久的“两会”上,“三农”问题再次成为被关注的焦点,其中农业通信、农业信息化等问题成为代表们探讨的热点话题。虽然我们不愿意看到,但是不可否认的是,目前农村通信状况普遍落后,农村与城市之间的“数字鸿沟”也越拉越大。面临“十五”计划要求的95%行政村通电话的目标,信息产业部及众多运营商加大了对农村通信重视程度和工作力度。重压之下,国内农村通信发展中存在的一些问题开始逐渐显现。我们必须承认,目前国内农村通信还没有走上成熟、良性的发展之路,尚处于发展过渡期。那么在这个过渡期,还有哪些因素困扰农村通信的发展?其中哪些技术手段将成为有效的突破口?另外,如何根据农村、农业、农民的特点和需要开发出具有吸引力的业务,提供农村市场真正需要的服务,促进农村信息化?……这些是电信企业需要深入思考的问题。为此本期“新电信沙龙”特邀信息产业部电信管理局苏金生局长、中国卫星通信集团公司郭浩副总经理、信息产业部电信研究院游五洋及人民邮电报社张英等几位长期以来一直关注国内农村通信发展的权威人士,就目前农村通信如何走好“过渡期”展开深入分析与探讨。 展开更多
关键词 information China GREAT digital area the more CLEAR and like open task With SHOW OUR top hot gap is New And all be
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Associative Tasks Computing Offloading Scheme in Internet of Medical Things with Deep Reinforcement Learning
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作者 Jiang Fan Qin Junwei +1 位作者 Liu Lei Tian Hui 《China Communications》 SCIE CSCD 2024年第4期38-52,共15页
The Internet of Medical Things(Io MT) is regarded as a critical technology for intelligent healthcare in the foreseeable 6G era. Nevertheless, due to the limited computing power capability of edge devices and task-rel... The Internet of Medical Things(Io MT) is regarded as a critical technology for intelligent healthcare in the foreseeable 6G era. Nevertheless, due to the limited computing power capability of edge devices and task-related coupling relationships, Io MT faces unprecedented challenges. Considering the associative connections among tasks, this paper proposes a computing offloading policy for multiple-user devices(UDs) considering device-to-device(D2D) communication and a multi-access edge computing(MEC)technique under the scenario of Io MT. Specifically,to minimize the total delay and energy consumption concerning the requirement of Io MT, we first analyze and model the detailed local execution, MEC execution, D2D execution, and associated tasks offloading exchange model. Consequently, the associated tasks’ offloading scheme of multi-UDs is formulated as a mixed-integer nonconvex optimization problem. Considering the advantages of deep reinforcement learning(DRL) in processing tasks related to coupling relationships, a Double DQN based associative tasks computing offloading(DDATO) algorithm is then proposed to obtain the optimal solution, which can make the best offloading decision under the condition that tasks of UDs are associative. Furthermore, to reduce the complexity of the DDATO algorithm, the cacheaided procedure is intentionally introduced before the data training process. This avoids redundant offloading and computing procedures concerning tasks that previously have already been cached by other UDs. In addition, we use a dynamic ε-greedy strategy in the action selection section of the algorithm, thus preventing the algorithm from falling into a locally optimal solution. Simulation results demonstrate that compared with other existing methods for associative task models concerning different structures in the Io MT network, the proposed algorithm can lower the total cost more effectively and efficiently while also providing a tradeoff between delay and energy consumption tolerance. 展开更多
关键词 associative tasks cache-aided procedure double deep Q-network Internet of Medical Things(IoMT) multi-access edge computing(MEC)
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Multi-Agent Deep Deterministic Policy Gradien-Based Task Offloading Resource Allocation Joint Offloading
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作者 Xuan Zhang Xiaohui Hu 《Journal of Computer and Communications》 2024年第6期152-168,共17页
With the advancement of technology and the continuous innovation of applications, low-latency applications such as drones, online games and virtual reality are gradually becoming popular demands in modern society. How... With the advancement of technology and the continuous innovation of applications, low-latency applications such as drones, online games and virtual reality are gradually becoming popular demands in modern society. However, these applications pose a great challenge to the traditional centralized mobile cloud computing paradigm, and it is obvious that the traditional cloud computing model is already struggling to meet such demands. To address the shortcomings of cloud computing, mobile edge computing has emerged. Mobile edge computing provides users with computing and storage resources by offloading computing tasks to servers at the edge of the network. However, most existing work only considers single-objective performance optimization in terms of latency or energy consumption, but not balanced optimization in terms of latency and energy consumption. To reduce task latency and device energy consumption, the problem of joint optimization of computation offloading and resource allocation in multi-cell, multi-user, multi-server MEC environments is investigated. In this paper, a dynamic computation offloading algorithm based on Multi-Agent Deep Deterministic Policy Gradient (MADDPG) is proposed to obtain the optimal policy. The experimental results show that the algorithm proposed in this paper reduces the delay by 5 ms compared to PPO, 1.5 ms compared to DDPG and 10.7 ms compared to DQN, and reduces the energy consumption by 300 compared to PPO, 760 compared to DDPG and 380 compared to DQN. This fully proves that the algorithm proposed in this paper has excellent performance. 展开更多
关键词 Edge Computing task Offloading Deep Reinforcement Learning Resource Allocation MADDPG
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QoS-Constrained,Reliable and Energy-Efficient Task Deployment in Cloud Computing
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作者 Zhenghui Zhang Yuqi Fan 《计算机科学与技术汇刊(中英文版)》 2024年第1期22-31,共10页
Reliability,QoS and energy consumption are three important concerns of cloud service providers.Most of the current research on reliable task deployment in cloud computing focuses on only one or two of the three concer... Reliability,QoS and energy consumption are three important concerns of cloud service providers.Most of the current research on reliable task deployment in cloud computing focuses on only one or two of the three concerns.However,these three factors have intrinsic trade-off relationships.The existing studies show that load concentration can reduce the number of servers and hence save energy.In this paper,we deal with the problem of reliable task deployment in data centers,with the goal of minimizing the number of servers used in cloud data centers under the constraint that the job execution deadline can be met upon single server failure.We propose a QoS-Constrained,Reliable and Energy-efficient task replica deployment(QSRE)algorithm for the problem by combining task replication and re-execution.For each task in a job that cannot finish executing by re-execution within deadline,we initiate two replicas for the task:main task and task replica.Each main task runs on an individual server.The associated task replica is deployed on a backup server and completes part of the whole task load before the main task failure.Different from the main tasks,multiple task replicas can be allocated to the same backup server to reduce the energy consumption of cloud data centers by minimizing the number of servers required for running the task replicas.Specifically,QSRE assigns the task replicas with the longest and the shortest execution time to the backup servers in turn,such that the task replicas can meet the QoS-specified job execution deadline under the main task failure.We conduct experiments through simulations.The experimental results show that QSRE can effectively reduce the number of servers used,while ensuring the reliability and QoS of job execution. 展开更多
关键词 Cloud Computing task Deployment RELIABILITY Quality of Service Energy Consumption
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Towards a Model-Driven IEC 61131-Based Development Process in Industrial Automation 被引量:1
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作者 Kleanthis Thramboulidis Georg Frey 《Journal of Software Engineering and Applications》 2011年第4期217-226,共10页
The IEC 61131-3 standard defines a model and a set of programming languages for the development of industrial automation software. It is widely accepted by industry and most of the commercial tool vendors advertise co... The IEC 61131-3 standard defines a model and a set of programming languages for the development of industrial automation software. It is widely accepted by industry and most of the commercial tool vendors advertise compliance with it. On the other side, Model Driven Development (MDD) has been proved as a quite successful paradigm in general-purpose computing. This was the motivation for exploiting the benefits of MDD in the industrial automation domain. With the emerging IEC 61131 specification that defines an object-oriented (OO) extension to the function block model, there will be a push to the industry to better exploit the benefits of MDD in automation systems development. This work discusses possible alternatives to integrate the current but also the emerging specification of IEC 61131 in the model driven development process of automation systems. IEC 61499, UML and SysML are considered as possible alternatives to allow the developer to work in higher layers of abstraction than the one supported by IEC 61131 and to more effectively move from requirement specifications into the implementation model of the system. 展开更多
关键词 Industrial AUTOMATION Systems Model driven DEVELOPMENT IEC 61131 System Modeling UML SYSML IEC 61499 DEVELOPMENT Process
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Numerical Investigation of Lid-Driven Deep Cavity with Local Grid Refinement of MRT-LBM
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作者 Dongdong Wan Guichao Wang Songying Chen 《Journal of Beijing Institute of Technology》 EI CAS 2019年第3期536-548,共13页
In the case of lid-driven deep cavity flow, the effects of different resolutions of local grid refinement have been studied in the frame of multiple relaxation times (MRT) lattice Boltzmann method (LBM). In all the ca... In the case of lid-driven deep cavity flow, the effects of different resolutions of local grid refinement have been studied in the frame of multiple relaxation times (MRT) lattice Boltzmann method (LBM). In all the cases, the aspect ratio and Reynolds number are set as 1.5 and 3.200, respectively. First, the applied method is validated by comparing it with two reported works, with which agreements are reached. Then, six separate degrees of local grid refinement at the upper left corner, i.e. purely coarse grid, including 1/64, 1/32, 1/16, 1/8, 1/4 refinements of the lattice number in the width direction have been studied in detail. The results give the following indications:① The refinement degrees lower than 1/8 produce similar results;② For single corner refinement, 1/4 refinement is adequate for clearing the noises in the singularity zone to a large extent;③ New noise around the interface between coarse and fine zones are introduced by local grid refinement. Finally, refinement of entire subzone neighboring the lid is examined to avoid introducing new noises and it has been found effective. 展开更多
关键词 numerical investigation lid-driven DEEP CAVITY local grid REFINEMENT lattice BOLTZMANN method (LBM) multiple relaxation time (MRT)
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银行间外币买卖业务:中国外汇市场发展的重要平台——苏格兰皇家银行中国区总经理,上海分行行长李权博士专访
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作者 许琳 周欢 陈敏 《中国货币市场》 2005年第4期36-38,共3页
苏格兰皇家银行简介RBS成立于1727年,是欧洲历史最悠久的金融机构之一。按股票市值计算,它分别位居英国第二、欧洲第二、世界第五。RBS在英国已设有2200家分行,并正在扩大欧洲、美国及亚太区的经营。其中,在美国的全资子银行Citizens Fi... 苏格兰皇家银行简介RBS成立于1727年,是欧洲历史最悠久的金融机构之一。按股票市值计算,它分别位居英国第二、欧洲第二、世界第五。RBS在英国已设有2200家分行,并正在扩大欧洲、美国及亚太区的经营。其中,在美国的全资子银行Citizens Financial Group,是美国国内第八大商业银行(以存款而论)。此外,RBS已在世界各主要金融中心——伦敦、纽约、新加坡、东京、香港、悉尼以及上海开展业务。RBS是英国最大的商业银行,所占的市场份额在25%~30%左右。2004年,RBS的收入增长18%,达到228亿英镑;税前利润增长了14%;达到69亿英镑,调整后的每股收益增长10%,达到172.5便士。 展开更多
关键词 Group 2004
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A Task-driven Medical Teaching Design under the Guidance of B-learning
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作者 Jie MA Haiping PENG Ming LEI 《International Journal of Technology Management》 2013年第12期65-67,共3页
关键词
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