In order to achieve dynamical optimization of mobility load balancing,we analyze the conflict between mobility load balancing and mobility robustness optimization caused by the improper operation of handover parameter...In order to achieve dynamical optimization of mobility load balancing,we analyze the conflict between mobility load balancing and mobility robustness optimization caused by the improper operation of handover parameters.To this end,a method of Handover Parameters Adjustment for Conflict Avoidance(HPACA)is proposed.Considering the movement of users,HPCAC can dynamically adjust handover range to optimize the mobility load balancing.The movement of users is an important factor of handover,which has a dramatic impact on system performance.The numerical evaluation results show the proposed approach outperforms the existing method in terms of throughput,call blocking ratio,load balancing index,radio link failure ratio,ping-pong handover ratio and call dropping ratio.展开更多
Because of the influence of human activities, the evolution of the Modaomen Estuary is no longer a purely natural process. We used a long-term morphodynamic model （PRD-LTMM-10） to study the evolution of the estuary ...Because of the influence of human activities, the evolution of the Modaomen Estuary is no longer a purely natural process. We used a long-term morphodynamic model （PRD-LTMM-10） to study the evolution of the estuary from 1977 to 1988. The model incorporated modules for riprap-siltation promotion and waterway dredging. The model can simulate the morphodynamic evolutionary processes occurring in the Modaomen Estuary during the period of interest. We were able to isolate the long-term influences of various human engineering activities and the roles of natural factors in estuarine evolution. The governance projects had the largest effect on the natural development of the estuary, resulting in larger siltation on the west side. Installation of riprap and reclamation of submerged land resulted in scouring of the main Hengzhou Channel causing deep trough out-shift. Severe siltation narrowed the upper end of the Longshiku Deep Trough.展开更多
At present, the major drawback for mobile phones is the issue of power consumption. As one of the alternatives to decrease the power consumption of standard, power-hungry location-based services usually require the kn...At present, the major drawback for mobile phones is the issue of power consumption. As one of the alternatives to decrease the power consumption of standard, power-hungry location-based services usually require the knowledge of how individual phone features consume power. A typical phone feature is that the applications related to multimedia streaming utilize more power while receiving, processing, and displaying the multimedia contents, thus contributing to the increased power consumption. There is a growing concern that current battery modules have limited capability in fulfilling the long-term energy need for the progress on the mobile phone because of increasing power consumption during multimedia streaming processes. Considering this, in this paper, we provide an offline meaning sleep-mode method to compute the minimum power consumption comparing with the power-on solution to save power by implementing energy rate adaptation(RA) mechanism based on mobile excess energy level purpose to save battery power use. Our simulation results show that our RA method preserves efficient power while achieving better throughput compared with the mechanism without rate adaptation(WRA).展开更多
Vehicular ad hoc networks （VANETs） that use the IEEE 802.11p communication standard face a number of challenges, not least when it comes to safety messages on the VANET control channel （CCH） where short delay time...Vehicular ad hoc networks （VANETs） that use the IEEE 802.11p communication standard face a number of challenges, not least when it comes to safety messages on the VANET control channel （CCH） where short delay times and reliable delivery are of pri- mary importance. In this paper we propose a vehicular machine-to-machine （VM2M） overlay network that uses Long Term Evolu- tion （LTE） physical random access channel （PRACH） to emulate VANET CCH. The overlay network uses dedicated preambles to separate vehicular traffic from regular LTE traffic and a cartier sense multiple access with collision avoidance （CSMA-CA） layer similar to the one used in IEEE 802.15.4 to avoid the four step handshake and the overhead it incurs. The performance of the pro- posed overlay is evaluated under a wide range of PRACH parameters which conform to the scenarios with high vehicle velocities and large distances between roadside units （RSUs） that may be encountered in rural areas and on highways.展开更多
This paper proposes a deformation evolution and perceptual prediction methodology for additive manufacturing of lightweight composite driven by hybrid digital twins(HDT).In order to improve manufacturing quality of ir...This paper proposes a deformation evolution and perceptual prediction methodology for additive manufacturing of lightweight composite driven by hybrid digital twins(HDT).In order to improve manufacturing quality of irregular lightweight composite through boosting conceptual design in aeronautic and aerospace engineering,the HDT meaning hybridization of physical and digital domains,including deformation and energy efficiency can be built,where the essential parameters can be perceptually predicted in advance,by virtue of the fusion of physical sensors and digital information.The long short term memory(LSTM)can be employed to void vanishing gradient problem and improve predicting precision via Recurrent Neural Networks,thereby laying a foundation for the HDT.The diverse manufacturing requirements of different regions are integrated into the parameters designing phase by attaching region weights confirmed via empiricism and in-service simulation.The effects of slicing strategy and external support structures on manufacturing quality are considered from the perspective of improving dimensional accuracy.The manufacturing efficiency and comprehensive costs are accounted as consideration factors,which are perceptually predicted via LSTM.The designed manufacturing parameters through HDT were virtually examined by evaluating the deformation and equivalent stress distributions of fabricated lightweight component with composite material through AM process simulation.The physical experiments were conducted to verify the HDT-based pre-designing and optimization method of manufacturing parameters via fused deposition modeling(FDM).The energy consumption of actual manufacturing process was measured via digital power meter and applied to evaluate accuracy of perceptual prediction outcomes.The dimensional accuracy and distortion distribution of the manufactured lightweight prototype made with composite material were measured through the coordinate measuring machine(CMM)and 3D optical scanner.The proposed method demonstrates effectiveness in improving manufacturing quality and accurately predicting energy consumption,which have been verified with a three-way solenoid valve element,in which the maximum deformation was reduced by 39.78%and the mean absolute percentage error for perceptual prediction was 3.76%.展开更多
文章探讨长期演进(Long Term Evolution,LTE)无线通信技术与物联网技术的融合在物联网网关设计中的应用。LTE技术具有网络容量大、吞吐量高和并行传输能力强的优势,结合物联网技术的智能交互和信息化网络环境,共同提升物联网的连接效率...文章探讨长期演进(Long Term Evolution,LTE)无线通信技术与物联网技术的融合在物联网网关设计中的应用。LTE技术具有网络容量大、吞吐量高和并行传输能力强的优势,结合物联网技术的智能交互和信息化网络环境,共同提升物联网的连接效率和数据传输稳定性。基于对LTE无线通信和物联网技术的简要分析,探索基于LTE无线通信的物联网网关设计。使用CMW500无线设备空口综合性测试仪与SecureCRT终端仿真程序测试网关联网功能。测试结果显示,该网关设计能够搜网成功并连接网络,具备一定普适性。展开更多
随着科技的不断发展,人们对信息服务的需求越来越高。在无线通信技术方面,长期演进(Long Term Evolution,LTE)被广泛应用于移动通信领域,因其高速、高质量的数据传输能力而备受青睐。物联网技术的出现和发展为各行各业带来了巨大的机遇...随着科技的不断发展,人们对信息服务的需求越来越高。在无线通信技术方面,长期演进(Long Term Evolution,LTE)被广泛应用于移动通信领域,因其高速、高质量的数据传输能力而备受青睐。物联网技术的出现和发展为各行各业带来了巨大的机遇和挑战。将LTE无线通信技术与物联网技术相结合,可以进一步提高用户的信息服务体验,为后续发展提供坚实的基础。展开更多
文章提出一种融合ZigBee与长期演进(Long Term Evolution,LTE)的智能交通通信网络设计与实现方案,旨在提升智能交通系统的数据传输效率、实时性以及安全性。通过结合ZigBee的低功耗、短距离通信优势和LTE的广覆盖、高速率特点,构建了多...文章提出一种融合ZigBee与长期演进(Long Term Evolution,LTE)的智能交通通信网络设计与实现方案,旨在提升智能交通系统的数据传输效率、实时性以及安全性。通过结合ZigBee的低功耗、短距离通信优势和LTE的广覆盖、高速率特点,构建了多层次、互补性的通信网络架构。该系统不仅实现了车辆间及车辆与基础设施间的实时信息交互,还优化了数据传输路径,降低了网络能耗,为智能交通系统的全面发展提供了有力支持。展开更多
长期演进(Long Term Evolution,LTE)作为当前主流的无线通信技术之一,其性能优化是当前研究的热点。文章针对LTE网络中的资源分配问题展开研究,通过分析正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术的基本原理,...长期演进(Long Term Evolution,LTE)作为当前主流的无线通信技术之一,其性能优化是当前研究的热点。文章针对LTE网络中的资源分配问题展开研究,通过分析正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术的基本原理,深入探讨其资源分配问题。针对传统粒子群优化(Particle Swarm Optimization,PSO)算法在资源分配过程中存在的局限性,文章研究一种基于混沌优化的PSO算法,以提高算法的全局搜索能力和收敛速度。通过在NS-3仿真平台上进行实验验证,结果表明混沌优化的PSO算法在不同网络负载情况下均能有效增加系统吞吐量,相比传统PSO算法具有更好的性能表现。展开更多
基金supported by the National Natural Science Foundation of China under Grant No.61071118the National Basic Research Program of China(973 Program)under Grant No.2012CB316004+1 种基金Special Fund of Chongqing Key Laboratory(CSTC)Chongqing Municipal Education Commission’s Science and Technology Research Project under Grant No.KJ111506
文摘In order to achieve dynamical optimization of mobility load balancing,we analyze the conflict between mobility load balancing and mobility robustness optimization caused by the improper operation of handover parameters.To this end,a method of Handover Parameters Adjustment for Conflict Avoidance(HPACA)is proposed.Considering the movement of users,HPCAC can dynamically adjust handover range to optimize the mobility load balancing.The movement of users is an important factor of handover,which has a dramatic impact on system performance.The numerical evaluation results show the proposed approach outperforms the existing method in terms of throughput,call blocking ratio,load balancing index,radio link failure ratio,ping-pong handover ratio and call dropping ratio.
文摘Because of the influence of human activities, the evolution of the Modaomen Estuary is no longer a purely natural process. We used a long-term morphodynamic model （PRD-LTMM-10） to study the evolution of the estuary from 1977 to 1988. The model incorporated modules for riprap-siltation promotion and waterway dredging. The model can simulate the morphodynamic evolutionary processes occurring in the Modaomen Estuary during the period of interest. We were able to isolate the long-term influences of various human engineering activities and the roles of natural factors in estuarine evolution. The governance projects had the largest effect on the natural development of the estuary, resulting in larger siltation on the west side. Installation of riprap and reclamation of submerged land resulted in scouring of the main Hengzhou Channel causing deep trough out-shift. Severe siltation narrowed the upper end of the Longshiku Deep Trough.
基金supported by X-Project funded by the Ministry of Science,ICT&Future Planning under Grant No.NRF-2015R1A2A1A16074929
文摘At present, the major drawback for mobile phones is the issue of power consumption. As one of the alternatives to decrease the power consumption of standard, power-hungry location-based services usually require the knowledge of how individual phone features consume power. A typical phone feature is that the applications related to multimedia streaming utilize more power while receiving, processing, and displaying the multimedia contents, thus contributing to the increased power consumption. There is a growing concern that current battery modules have limited capability in fulfilling the long-term energy need for the progress on the mobile phone because of increasing power consumption during multimedia streaming processes. Considering this, in this paper, we provide an offline meaning sleep-mode method to compute the minimum power consumption comparing with the power-on solution to save power by implementing energy rate adaptation(RA) mechanism based on mobile excess energy level purpose to save battery power use. Our simulation results show that our RA method preserves efficient power while achieving better throughput compared with the mechanism without rate adaptation(WRA).
文摘Vehicular ad hoc networks （VANETs） that use the IEEE 802.11p communication standard face a number of challenges, not least when it comes to safety messages on the VANET control channel （CCH） where short delay times and reliable delivery are of pri- mary importance. In this paper we propose a vehicular machine-to-machine （VM2M） overlay network that uses Long Term Evolu- tion （LTE） physical random access channel （PRACH） to emulate VANET CCH. The overlay network uses dedicated preambles to separate vehicular traffic from regular LTE traffic and a cartier sense multiple access with collision avoidance （CSMA-CA） layer similar to the one used in IEEE 802.15.4 to avoid the four step handshake and the overhead it incurs. The performance of the pro- posed overlay is evaluated under a wide range of PRACH parameters which conform to the scenarios with high vehicle velocities and large distances between roadside units （RSUs） that may be encountered in rural areas and on highways.
基金Supported by National Key Research and Development Project of China(Grant No.2022YFB3303303)Zhejiang Provincial Research and Development Project of China(Grant No.LGG22E050010)Key Open Fund of State Key Laboratory of Materials Processing and Die and Mould Technology of China(Grant No.P2024-001).
文摘This paper proposes a deformation evolution and perceptual prediction methodology for additive manufacturing of lightweight composite driven by hybrid digital twins(HDT).In order to improve manufacturing quality of irregular lightweight composite through boosting conceptual design in aeronautic and aerospace engineering,the HDT meaning hybridization of physical and digital domains,including deformation and energy efficiency can be built,where the essential parameters can be perceptually predicted in advance,by virtue of the fusion of physical sensors and digital information.The long short term memory(LSTM)can be employed to void vanishing gradient problem and improve predicting precision via Recurrent Neural Networks,thereby laying a foundation for the HDT.The diverse manufacturing requirements of different regions are integrated into the parameters designing phase by attaching region weights confirmed via empiricism and in-service simulation.The effects of slicing strategy and external support structures on manufacturing quality are considered from the perspective of improving dimensional accuracy.The manufacturing efficiency and comprehensive costs are accounted as consideration factors,which are perceptually predicted via LSTM.The designed manufacturing parameters through HDT were virtually examined by evaluating the deformation and equivalent stress distributions of fabricated lightweight component with composite material through AM process simulation.The physical experiments were conducted to verify the HDT-based pre-designing and optimization method of manufacturing parameters via fused deposition modeling(FDM).The energy consumption of actual manufacturing process was measured via digital power meter and applied to evaluate accuracy of perceptual prediction outcomes.The dimensional accuracy and distortion distribution of the manufactured lightweight prototype made with composite material were measured through the coordinate measuring machine(CMM)and 3D optical scanner.The proposed method demonstrates effectiveness in improving manufacturing quality and accurately predicting energy consumption,which have been verified with a three-way solenoid valve element,in which the maximum deformation was reduced by 39.78%and the mean absolute percentage error for perceptual prediction was 3.76%.
文摘文章探讨长期演进(Long Term Evolution,LTE)无线通信技术与物联网技术的融合在物联网网关设计中的应用。LTE技术具有网络容量大、吞吐量高和并行传输能力强的优势,结合物联网技术的智能交互和信息化网络环境,共同提升物联网的连接效率和数据传输稳定性。基于对LTE无线通信和物联网技术的简要分析,探索基于LTE无线通信的物联网网关设计。使用CMW500无线设备空口综合性测试仪与SecureCRT终端仿真程序测试网关联网功能。测试结果显示,该网关设计能够搜网成功并连接网络,具备一定普适性。
文摘随着科技的不断发展,人们对信息服务的需求越来越高。在无线通信技术方面,长期演进(Long Term Evolution,LTE)被广泛应用于移动通信领域,因其高速、高质量的数据传输能力而备受青睐。物联网技术的出现和发展为各行各业带来了巨大的机遇和挑战。将LTE无线通信技术与物联网技术相结合,可以进一步提高用户的信息服务体验,为后续发展提供坚实的基础。
文摘文章提出一种融合ZigBee与长期演进(Long Term Evolution,LTE)的智能交通通信网络设计与实现方案,旨在提升智能交通系统的数据传输效率、实时性以及安全性。通过结合ZigBee的低功耗、短距离通信优势和LTE的广覆盖、高速率特点,构建了多层次、互补性的通信网络架构。该系统不仅实现了车辆间及车辆与基础设施间的实时信息交互,还优化了数据传输路径,降低了网络能耗,为智能交通系统的全面发展提供了有力支持。
文摘长期演进(Long Term Evolution,LTE)作为当前主流的无线通信技术之一,其性能优化是当前研究的热点。文章针对LTE网络中的资源分配问题展开研究,通过分析正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)技术的基本原理,深入探讨其资源分配问题。针对传统粒子群优化(Particle Swarm Optimization,PSO)算法在资源分配过程中存在的局限性,文章研究一种基于混沌优化的PSO算法,以提高算法的全局搜索能力和收敛速度。通过在NS-3仿真平台上进行实验验证,结果表明混沌优化的PSO算法在不同网络负载情况下均能有效增加系统吞吐量,相比传统PSO算法具有更好的性能表现。
