Optimal design for manipulation of random consensus over discrete information in networked systems     

Sidney Roberto Carvalho  Ubirajara Franco Moreno 《Journal of The Franklin Institute》2021,358(9):5039-5072

In distributed and cooperative systems, the network structure is determinant to the success of the strategy adopted to solve complex tasks. Those systems are primarily governed by consensus protocols whose convergence is intrinsically dependent on the network topology. Most of the consensus algorithms deal with continuous values and perform average-based strategies to reach cohesion over the exchanged information. However, many problems demand distributed consensus over countable values, that cannot be handled by traditional protocols. In such a context, this work presents an approach based on semidefinite programming to design the optimal weights of a network adjacency matrix, in order to control the convergence of a distributed random consensus protocol for variables at the discrete-space domain, based on the voter model. As a second contribution, this work uses Markov theory and the biological inspiration of epidemics to find out a dynamical spreading model that can predict the information diffusion over this discrete consensus protocol. Also, convergence properties and equilibrium points of the proposed model are presented regarding the network topology. Finally, extensive numerical simulations evaluate the effectiveness of the proposed consensus algorithm, its spreading model, and the approach for optimal weight design.  相似文献   

Intersample optimization in a sampled-data control system using the redundancy of a dual-rate system     

R. Yasui  N. Kawaguchi  T. Sato  A. Inoue 《Journal of The Franklin Institute》2021,358(8):4483-4502

The present study discusses the design method for controlling a single-input/single-output linear time-invariant dual-rate system, where the sampling interval of the plant output is longer than the holding interval of the control input. In such a dual-rate system, the intersample output might oscillate even when the sampled output converges to the reference input in the steady state. In a conventional ripple-free method, an existing control law is extended by introducing an exogenous variable, which is independent of the discrete-time sampled response, and the exogenous variable is designed for eliminating the steady-state intersample ripples without changing the existing sampled response. In another method, since a control law is designed such that the intersample performance is optimized, the intersample ripples are eliminated in the transient as well as steady states. However, the preservation of an existing sampled response is not taken into account. The present study proposes a new design method for eliminating the intersample ripples subject to the existing sampled response. In the proposed method, the continuous-time index is optimized subject to the existing discrete-time response. As a result, the intersample ripples are eliminated in the transient as well as steady states, and the existing discrete-time sampled response is maintained. The proposed method is compared to the conventional dual-rate design methods in numerical examples, and the effectiveness of the method is demonstrated.  相似文献   

关于空间科学发展的一些思考          下载免费PDF全文

顾逸东 《中国科学院院刊》2022,37(8):1031-1049

空间科学是利用空间飞行器探索宇宙和自然规律,开展特殊实验的大规模科学活动,为当代科学发展作出了重大贡献。文章概述了国际空间科学的重大突破,分析了空间科学、载人探索活动的发展脉络和新趋势,回顾了我国空间科学近20年来的发展成就,总结了存在的问题和差距,强调空间科学的战略地位及其对我国科技、航天和国家长远发展的重要性。加大对空间科学的投入、制定国家空间科学规划和建立稳定预算制度是我国空间科学长期稳定发展的保证。建议充分利用科学气球、探空火箭等各种途径夯实研究基础,加强理论与实验技术相结合,培养大批高素质科学家,深化国际合作,完善科学任务管理模式等,走出中国特色的空间科学创新发展道路。  相似文献   

基于LiDAR点云特征和模型拟合的高压线提取     

杨渊  陈凤翔  虢韬  时磊  王成  罗鑫 《中国科学院大学学报》2018,35(5):612-616

高压线数字化是数字电网建设和线路智能巡检的核心内容,机载LiDAR在高压线三维数字重建中具有独特的优势。提出一种从输电走廊机载LiDAR点云数据自动快速高精度提取完整电力线点的方法。首先基于点云的空间分布特征粗提取电力线点,并通过改进Hough变换和RANSAC抛物线拟合法剔除噪点,然后分别进行电力线在平面和垂直面上的分股,结合单股电力线的平面直线模型和垂直面上的抛物线模型,采用模型生长的方法提取完整的电力线点。试验结果表明,该方法提取的电力线点云的精度可达99.6%。  相似文献   

工作家庭冲突、上司支持感与工作满意度的关系研究——基于中层职业经理人的实证分析   总被引：1，自引：0，他引：1  

李锡元  高婧 《科学学与科学技术管理》2011,32(2)

选取中层职业经理人这一特殊群体,研究他们的工作家庭冲突问题,同时特别关注了中层职业经理人的上司支持感这一要素,试图探究其在工作家庭冲突与工作满意度之间所起到的作用及影响.对306名中层职业经理人做了调查,结果发现:工作家庭冲突对工作满意度具有显著的负向预测作用;而他们感受到的上司支持感对工作满意度具有显著的正向预测作用;此外,上司支持感能够在工作家庭冲突对工作满意度的影响上起到一定的调节作用.  相似文献   

Reading a mentoring situation: one aspect of learning to mentor     

《Teaching and Teacher Education》2001,17(1):75-88

This paper describes and interprets the meanings that one novice mentor attributes to ‘reading a mentoring situation’, an organizing metaphor for describing how one experienced teacher of English learns to analyze one aspect of her learning in talking to mentor teachers of English throughout her first year of induction into mentoring. The study revealed that learning to become a mentor is a conscious process of induction into a different teaching context and does not ‘emerge’ naturally from being a good teacher of children. Thus, at an operational level, teacher education programs should prepare teachers for this passage by encouraging the dissemination of in-service courses that allow novice mentors the opportunity to articulate the construction of their new role. Such courses can be structured as ‘learning conversations’ whereby mentors are encouraged to reflect on their roles in the company of fellow mentors, mediated by an experienced mentor of mentors.  相似文献   

从体育竞赛现状谈加强体育法制建设的迫切性   总被引：3，自引：0，他引：3  

毛坤  周凤桐  陈彩香 《吉林体育学院学报》2005,21(2):22-23

体育法是国家基本法律之一，对促进体育事业的健康发展具有十分重要的意义。通过分析体育比赛中暴露出的问题，指出中国的体育立法存在体育立法体系不完善、立法层次低和立法主体多元化等问题。为净化体育比赛环境，保障体育比赛的公平公正，必须加强体育法制建设，制订详尽的体育法律法规。  相似文献   

31种科技期刊发行量调查及其对广告客户的影响   总被引：16，自引：3，他引：13  

肖志军  崔保国  苏洪余  李建辉  刘勇 《编辑学报》2002,14(6):437-438

通过了解31种科技期刊印数、实际发行量及其广告价格,分析实际发行量与公布的发行量的关系,以及广告价格与发行量的关系.结果表明,平均发行量为3 840册,普遍存在虚报现象,平均虚报百分率为290.5%,广告报价与期刊发行量的相关系数为0.16.认为期刊社提供的发行量与实际发行量出入很大,为了适应我国加入WTO后的形势,应当成立类似于美国发行量设计局(ABC)之类的审计机构.  相似文献   

镀膜双镜头多光谱相机的波段配准方法     

郑佳怡  方俊永  王潇  张晓红  刘学 《中国科学院大学学报》2022,39(3):377-385

针对镀膜双镜头多光谱相机波段多、数据量大、配准流程复杂的问题,提出一种基于改进SURF算法的快速配准方法。该方法首先完成对各波段图像的预处理,采用数字畸变模型采样法对各波段影像畸变进行校正;然后对畸变改正后的各波段图像利用快速版的SURF算法(F-SURF)进行配准。F-SURF算法从3个方面对原SURF算法进行改进,包括:依照匹配贡献度优化算法组数设置、舍弃算法旋转不变性以及引入渐进采样一致法进行特征点匹配等。通过地面及飞行实验数据进行算法验证,结果表明改进算法的配准精度优于经典SURF算法,且时间效率显著提升。  相似文献   

基于多源数据的中国UNESCO名录遗产地 可持续发展目标监测     

王普  杨瑞霞  梁勇奇  陈国龙  王心源 《中国科学院大学学报》2022,39(6):754-763

SDG11.4.1将保护世界遗产的“保护支出”作为评价遗产可持续发展目标的指标,其处于有方法无数据的状态,亟需具体数据和测算案例支持。利用48处中国UNESCO名录遗产的统计数据对SDG11.4.1指标进行测度和分析,基于Landsat遥感数据对4处自然遗产人为干预度进行变化监测分析。结果表明：1)单位面积支出可作为测度自然保护地(世界自然遗产、混合遗产、地质公园和生物圈保护区)可持续发展状态的指标,但不适用于文化遗产的测度。2)从资金投入角度看：自然保护地年均投入400万元/km²可作为优质发展目标阈值,年均投入80万~400万元/km²可作为发展状态良好的阈值。3)人为干预度作为扩展指标可以反映自然遗产地的可持续保护状态和趋势,可进一步在中国及其他国家类似保护地进行推广应用。  相似文献