Improved spectrum sharing algorithm based on feedback control information in cognitive radio networks

In order to avoid the system performance deterioration caused by the wireless fading channel and imperfect channel estimation in cognitive radio networks, the spectrum sharing problem with the consideration of feedback control information from the primary user is analyzed. An improved spectrum sharing algorithm based on the combination of the feedback control information and the optimization algorithm is proposed. The relaxation method is used to achieve the approximate spectrum sharing model, and the spectrum sharing strategy that satisfies the individual outage probability constraints can be obtained iteratively with the observed outage probability. Simulation results show that the proposed spectrum sharing algorithm can achieve the spectrum sharing strategy that satisfies the outage probability constraints and reduce the average outage probability without causing maximum transmission rate reduction of the secondary user.

Microscopic simulation of multi-lane traffic under dynamic tolling and information feedback

To investigate drivers' lane-changing behavior under different information feedback strategies,a microscopic traffic simulation based on the cellular automaton model was made on the typical freeway with a regular lane and a high-occupancy one. A new dynamic tolling scheme in terms of the real-time traffic condition on the high-occupancy lane was further designed to enhance the whole freeway's flow throughput. The results show that the mean velocity feedback strategy is generally more efficient than the travel time feedback strategy in correctly guiding drivers' lane choice behavior. Specifically,the toll level,lane-changing rate and freeway's throughput and congestion coefficient induced by the travel time feedback strategy oscillate with larger amplitude and longer period. In addition,the dynamic tolling scheme can make the high-occupancy lane less congested and maximize the freeway's throughput when the regular-lane inflow rate is larger than 0.45.

Leader-following coordination of multi-agent systems with information feedback

Based on the strategy of information feedback from followers to the leader, flocking control of a group of agents with a leader is studied. The leader tracks a pre-defined trajectory and at the same time the leader uses the feedback information from followers to the leader to modify its motion. The advantage of this control scheme is that it reduces the tracking errors and improves the robustness of the team cohesion to followers＇ faults. The results of simulation are provided to illustrate that information feedback can improve the performance of the system.

Information perception and feedback mechanism and key techniques of multi-modality human-robot interaction for service robots

With the increasing of the elderly population and the growing hearth care cost, the role of service robots in aiding the disabled and the elderly is becoming important. Many researchers in the world have paid much attention to heaRthcare robots and rehabilitation robots. To get natural and harmonious communication between the user and a service robot, the information perception/feedback ability, and interaction ability for service robots become more important in many key issues.

An Efficient CSI Feedback Scheme for Dual-Polarized MIMO Systems Using Layered Multi-Paths Information

Massive MIMO is one of tile enabling technologies tbr beyond 4G and 5G systems due to its ability to provide beamforming gain and reduce interference Dual-polarized antenna is widely adopted to accommodate a large number of antenna elements in limited space. However, current CSI（channel state information） feedback schemes developed in LTE for conventional MIMO systems are not efficient enough for massive MIMO systems since the overhead increases almost linearly with the number of antenna. Moreover, the codebook for massive MIMO will be huge and difficult to design with the LTE methodology. This paper proposes a novel CSI feedback scheme named layered Multi-paths Information based CSI Feedback （LMPIF）, which can achieve higher spectrum efficiency for dual-polarized antenna system with low feedback overhead. The MIMO channel is decomposed into long term components （multipath directions and amplitudes） and short term components （multipath phases）. The relationship between the two components and the optimal precoder is derived in closed form. To reduce the overhead, different granularities in feedback time have been applied for the long term components and short term components Link and system level simulation results prove that LMPIF can improve performance considerably with low CSI feedback overhead.

Position Optimization for Mobile Relay Communications with Constrained Energy over a Whole Horizontal Plane

This paper concerns the position optimization problem of a mobile relay over a whole horizontal plane.This problem is important because the position of a mobile relay directly affects the end-to-end performance,e.g.,reliability,connectivity,and data rate.In this paper,we propose a new position optimization scheme of a mobile relay over a whole horizontal plane based on the one-bit feedback information from the destination node,which improves the performance over the prior scheme whose position of the mobile relay is optimized over a fixed orbit.In the proposed scheme,the mobile relay is equipped with merely one single onboard antenna.Moreover,no prior information about the positions of both the source node and the destination node is required.Thus,the proposed scheme can work at low network resources scenario,which is particularly suitable for mobile relay communication with constrained energy,e.g.,the communications in a disaster area where the infrastructure is heavily damaged,volcano monitoring,and wireless powered communication networking.According to the characteristics of the proposed scheme,we further design two heuristic implementations to calculate the optimal position of a mobile relay over a whole horizontal plane.The first implementation has better steady performance whereas the second implementation has better convergence speed.We implement the proposed scheme and conduct an extensive performance comparison between the proposed scheme and prior schemes to verify the advantages of the proposed scheme.

密集建筑群下大断面隧道施工反馈分析及安全性控制研究

厦门梧村隧道施工影响区域内建筑物密集,具有超浅埋、大跨度、工艺复杂、工序繁多、地面建筑物保护要求高等高风险特征,在隧道施工过程中研究并实施复杂地质情况和周边环境条件下隧道的动态反馈分析方法。现场监测内容有建筑物及地表沉降、建筑物裂缝、建筑物倾斜、隧道拱顶沉降、隧道围岩收敛、土体深部位移、土体分层沉降、爆破震动、地下水位等,对重要建筑物还采用静力水准仪进行自动化监测。在对梧村隧道进行施工反馈分析过程中,按照ISO9001质量认证体系要求建立一个完善、高效的运作体系,根据城市隧道工程修建经验以及梧村隧道前期研究成果,对隧道施工对周边环境以及隧道自身结构的影响进行监测,除采取常规监测手段外,以建筑物不均匀沉降自动化监测、监测信息管理和预测预报系统、局域网和广域网进行监测信息反馈、桌面报警系统和电子显示板等预警设施等先进技术来开展施工反馈分析工作,使梧村隧道施工反馈分析工作具有鲜明的信息化特色。

全视角反馈评价在高校教育信息化绩效评价中的运用

全视角反馈评价是一种由多个评价者对被评价体进行全面评估的方法,将全视角反馈评价运用到高校绩效评价之中可以增加评价的真实性、可信性和透明度,通过多方反馈有利于找出高校教育信息化中存在的具体问题,并根据这些问题提出切实可行的措施来改善教育信息化绩效。

医院医疗器械不良事件反馈系统的构建

本文针对不良事件监测工作存在的问题,结合医疗机构实际情况,提出了建立不良事件监测的三级反馈模式。从政府监管部门、医疗机构、不良事件发生科室3方面进行层级反馈。这一系统的构建切实提升了医院各个部门不良事件反馈工作的效率,保证了监测工作有关信息的高效传达,提高了医疗机构医疗器械使用的安全性。

Feedback Stackelberg Solution for Mean-Field Type Stochastic Systems with Multiple Followers

This paper discusses feedback Stackelberg strategies for the continuous-time mean-field type stochastic systems with multiple followers in infinite horizon.First,optimal control problems of the followers are studied in the sense of Nash equilibrium.With the help of a set of generalized algebraic Riccati equations(GAREs),sufficient conditions for the solvability are put forward.Then,the leader faces a constrained optimal control problem by transforming the cost functional into a trace criterion.Employing the Karush-Kuhn-Tucker(KKT)conditions,necessary conditions are presented in term of the solvability of the cross-coupled stochastic algebraic equations(CSAEs).Moreover,feedback Stackelberg strategies are obtained based on the solutions of the CSAEs.In addition,an iterative scheme is introduced to obtain efficiently the solutions of the CSAEs.Finally,an example is given to shed light on the effectiveness of the proposed results.

单管分体柱塞式液压破碎锤

提出了一种新型的液压破碎锤结构原理,其创新特征有四点:第一点,一反液压破碎锤都有两条油管的常态,将其两条油管合二而一,即这一条油管既是供油管,也是回油管,实现了结构的重要创新;阀体不是装在缸体上,而是独立于缸体之外,可装在动臂的任何地方,阀与缸体之间只有一条油管联系,这是液压锤结构的一项重要创新;第二点,缸体为柱塞式,活塞只有前腔没有后腔;第三点,采用了压力反馈式液压破碎锤控制原理;第四点,在系统中引入了计算机,实现了数字化控制。针对新型液压破碎锤结构,本文提出了两项控制方案:计算机控制-信息化方案和纯机械式顺序阀控制方案。

Deformation mechanism and collapse treatment of the rock surrounding a shallow tunnel based on on-site monitoring

When tunnels are constructed at shallow depths in areas with poor geological conditions,such as portal sections,valleys and hillsides in regions with granitic bedrock,considerable excavation-induced deformation of the surrounding rock may occur,potentially resulting in tunnel collapses.The main reason for these problems is the lack of understanding of the deformation mechanism and evolution of the soft granitic rock surrounding the tunnel and the adoption of inappropriate construction technology and methods.This article analyzes the deformation mechanism of the rock surrounding a shallow tunnel based on in situ monitoring data as a case study and suggests that certain measures should be taken to effectively control the deformation of the surrounding rock and to minimize the potential for tunnel collapse.The results show that the deformation of the granitic soil surrounding the tunnel can be divided into three stages:the rapid deformation stage,the slow deformation stage and the stabilization stage.Appropriate construction methods should be carefully selected to ensure safety during tunnel excavation in the first stage.To avoid secondary disasters caused by tunnel collapses,three treatment measures may be implemented as part of safety management:enhancing the monitoring of the surrounding rock deformation,adjusting the construction methods and optimizing the support systems.In particular,accurate monitoring data and timely information feedback play a vital role in tunnel construction.Therefore,engineers with considerable engineering experience and professional knowledge are needed to analyze the monitoring data and make accurate predictions of tunnel deformation to ensure that reasonable measures are taken in the process of shallow tunnel excavation.

新信息时代模拟电子技术课程知识点强化实践与分析

针对课上听得懂、课下忘干净的问题,基于模拟电子技术课程培养方案和教学大纲,结合学生自身能力学习,设计了模拟电子技术知识点分级图。课上学习,课下巩固,基于新媒体信息传播方式,设计新颖的习题模式激发学生参与热情。建立师生反馈机制,快速响应教学需求,同步改进教学。

隧道围岩监控信息化应用

隧道围岩量测采用全站仪对隧道围岩净空变化、拱顶沉降进行测量,通过蓝牙将数据上传至手簿或移动终端设备,手簿或移动终端设备通过网络上传至服务器,后台服务器自动分析数据,推送到相关管理者移动客户端,相关管理者及时了解监测信息,危险情况下管理者能第一时间得到信息并采取措施,避免安全事故发生[1]。

基于改进的IFM-NSGAⅢ模型的武汉市土地利用优化配置

提出改进的信息反馈模型-第三代非支配排序遗传算法(information feedback model-non-dominated sorting genetic algorithmⅢ,IFM-NSGAⅢ),并将其用于土地利用优化:在NSGAⅢ基础上耦合IFM以实现多个目标的平衡。以武汉市为研究区,制定经济效益、生态效益、转换成本、不相容性、紧凑性共5个优化目标,检验模型的适用性。结果表明,模型能够生成多样化的土地利用模式满足不同发展需求,在生态效益优先的模式1中,与现状相比,其生态效益和经济效益分别提升了0.10%和6.24%。