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Deploying process modeling and attitude control of a satellite with a large deployable antenna 被引量:8
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作者 Zhigang Xing Gangtie Zheng 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2014年第2期299-312,共14页
Modeling and attitude control methods for a satellite with a large deployable antenna are studied in the present paper. Firstly, for reducing the model dimension, three dynamic models for the deploying process are dev... Modeling and attitude control methods for a satellite with a large deployable antenna are studied in the present paper. Firstly, for reducing the model dimension, three dynamic models for the deploying process are developed, which are built with the methods of multi-rigid-body dynam- ics, hybrid coordinate and substructure. Then an attitude control method suitable for the deploying process is proposed, which can keep stability under any dynamical parameter variation. Subse- quently, this attitude control is optimized to minimize attitude disturbance during the deploying process. The simulation results show that this attitude control method can keep stability and main- tain proper attitude variation during the deploying process, which indicates that this attitude con- trol method is suitable for practical applications. 展开更多
关键词 Attitude control communication satellite Deploying process modeling Disturbance rejection Large deployable antenna
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MDL-based root-mean-squared delay spread estimation for MIMO OFDM systems
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作者 徐晓东 井雅 尤肖虎 《Journal of Southeast University(English Edition)》 EI CAS 2004年第4期395-400,共6页
This paper studied the application of minimum description length (MDL) criterion for estimating root-mean-squared (RMS) delay spread (RDS) for MIMO OFDM systems. The analytic relationship between the powers and the co... This paper studied the application of minimum description length (MDL) criterion for estimating root-mean-squared (RMS) delay spread (RDS) for MIMO OFDM systems. The analytic relationship between the powers and the correlation matrix of multipath components established the feasibility of the application of the MDL criterion to RDS estimation. The estimator presented both the estimate of instantaneous RDS and the estimates of noise variance, channel power and SNR of current channel with low computational complexity. Given the powers of the estimated multipath components, the MDL criterion was adopted to acquire the number of paths and the time delays of each path of current channel without making eigendecomposition of the correlation matrix normally required by MDL criterion, following which the noise variance and the power of each path can be estimated. The power delay profile (PDP) and RDS of the current channel were achieved. Simulation results showed that the proposed estimator was insensitive to variance of SNR and robust against frequency-selectivity. 展开更多
关键词 communication channels (information theory) Delay control systems Fading (radio) Robustness (control systems) Signal processing Wireless telecommunication systems
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A Survey on Underwater Acoustic Sensor Networks: Perspectives on Protocol Design for Signaling, MAC and Routing 被引量:5
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作者 Mohammad Sharif-Yazd Mohammad Reza Khosravi Mohammad Kazem Moghimi 《Journal of Computer and Communications》 2017年第5期12-23,共12页
Underwater acoustic sensor networks (UASNs) are often used for environmental and industrial sensing in undersea/ocean space, therefore, these networks are also named underwater wireless sensor networks (UWSNs). Underw... Underwater acoustic sensor networks (UASNs) are often used for environmental and industrial sensing in undersea/ocean space, therefore, these networks are also named underwater wireless sensor networks (UWSNs). Underwater sensor networks are different from other sensor networks due to the acoustic channel used in their physical layer, thus we should discuss about the specific features of these underwater networks such as acoustic channel modeling and protocol design for different layers of open system interconnection (OSI) model. Each node of these networks as a sensor needs to exchange data with other nodes;however, complexity of the acoustic channel makes some challenges in practice, especially when we are designing the network protocols. Therefore based on the mentioned cases, we are going to review general issues of the design of an UASN in this paper. In this regard, we firstly describe the network architecture for a typical 3D UASN, then we review the characteristics of the acoustic channel and the corresponding challenges of it and finally, we discuss about the different layers e.g. MAC protocols, routing protocols, and signal processing for the application layer of UASNs. 展开更多
关键词 ACOUSTIC communications UNDERWATER ACOUSTIC Sensor Networks (UASNs) UNDERWATER Medium Access control (Underwater MAC) UNDERWATER ROUTING Distributed Signal processing
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广东省不同结核病防治体系模式的工作成效分析 被引量:10
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作者 温保江 邓小懂 +1 位作者 冯光永 温文沛 《结核病与肺部健康杂志》 2019年第1期19-23,共5页
目的探索广东省不同结核病防控体系模式的工作成效并进行分析。方法对广东省肺结核监测报表中的2017年指标数据,2017年广东省统计局公布的各地市国内生产总值(GDP).以及2017年度广东省各地市工作总结、省督导地市的报告和广东省结核病... 目的探索广东省不同结核病防控体系模式的工作成效并进行分析。方法对广东省肺结核监测报表中的2017年指标数据,2017年广东省统计局公布的各地市国内生产总值(GDP).以及2017年度广东省各地市工作总结、省督导地市的报告和广东省结核病防治体系模式调研报告、史志材料进行综合分析。对不同政府投入下相同防治体系(防治结合的医院模式)及相同政府投入下不同体系(防治结合的医院模式与防治结合的门诊模式,防治结合与防治分开模式)的工作成效进行综合评价。结果2017年广东省各地方政府结核病防治投入在131.68万元,3614.90万元之间;政府投入的总效益在5811.39万元?277763.65万元之间。(1)不同政府投入下相同防治体系(防治结合的医院模式)工作成效对照(深圳市和汕头市):深圳市和汕头市人均政府投人分别为3.04元和1.41元;政府投入的总效益深圳市(134720.89万元)高于汕头市(27827.61万元);深圳市报告发病率(55.3/10万)低于汕头市(117.8/10万);深圳市登记率(45.9/10万)接近报告发病率(55.3/10万),汕头市登记率(47.6,10万)与报告发病率(117.8/10万)差距大。(2)相近政府投入下不同防治体系的工作成效对照:①防治结合的医院模式(佛山市)与防治结合的门诊模式(珠海市)成效对照:佛山市和珠海市人均政府投入分别为1.89元和1.83元;政府投入的总效益佛山市(9897&06万元)高于珠海市(36894.81万元);佛山市转诊到位率和成功治疗率分别93.4%和9』.8%;珠海市转诊到位率和成功治疗率均为95.8%,两市接近;佛山市报告发病率(49.0/10万)和登记率(49.0/10万)差距较小;珠海市报告发病率为71.3/10万.登记率为74.6/10万.两者差距较大。②防治分开模式(潮州市)和防治结合的医院模式(茂名市)成效对照:潮州市和茂名市人均政府投入分别为0.50元和0.48元;茂名市政府投入的总效益(33723.26万元)高于潮州市(5811.39万元);潮州市报告发病率(68.5/10万)高于茂名市(61.5/10万);潮州市登记率(27.7/10万)低于茂名市(53.8/10万)。结论政府投入水平对结核病防治体系的工作成效影响较大;在相同的政府投入水平下.防治结合的模式优于防治分开模式(“三位一体”模式);防治结合的医院模式优于防治结合的门诊模式。 展开更多
关键词 结核 传染病控制 卫生服务管理 结果与过程评价(卫生保健)
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RTEX A REAL TIME EXECUTIVE FOR DCCS
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作者 荣广颐 于娅 《Journal of Donghua University(English Edition)》 EI CAS 1989年第Z1期72-85,共14页
This paper presents the design idea and implementation of a real time multiprocess executivededicated to a distributed computer control system(abbreviated as DCCS),RTEX.The hostprecessor is an INTEL 8344 microcontroll... This paper presents the design idea and implementation of a real time multiprocess executivededicated to a distributed computer control system(abbreviated as DCCS),RTEX.The hostprecessor is an INTEL 8344 microcontroller proper for mini size industrial control work station.A real time executive is designed to provide a friendly environment for users to develop their ownapplied software.In consideration of reliability and ease of maintenance the executive is imple-mented by a hierarchical structure with eight layers which include user applied programs,net-work communication,real time clock manager,interprocess communication,processcoordination,process manager,memory manager,hardware.For practical purpose the networkcommunication software is implemented by four layers,namely physical,datalink,transport andapplication.The bottom two layers are designed according to the Bit Bus protocol,so that thework station is compatible with the INTEL distributed system.Three parts,the kernel,networkcommunication and facilities for system initialization and applied software development are in-cluded. 展开更多
关键词 distributed control computer-computer communication real-time system processes hierarchical structure KERNEL network communication MICROprocessOR PL/M-51
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传染病防控中的隔离措施 被引量:37
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作者 高秦伟 《中外法学》 CSSCI 北大核心 2020年第3期590-611,共22页
传染病防治法上规定对传染病患者、病原携带者、疑似患者及其密切接触者等采取隔离措施,目的在于阻绝传染病蔓延扩散。此种措施的实效为自古至今的重大疫情及其防治结果所证明,但亦引发了个人权利与公众健康所体现的公共利益之间的抵牾... 传染病防治法上规定对传染病患者、病原携带者、疑似患者及其密切接触者等采取隔离措施,目的在于阻绝传染病蔓延扩散。此种措施的实效为自古至今的重大疫情及其防治结果所证明,但亦引发了个人权利与公众健康所体现的公共利益之间的抵牾。在实务操作中,有关隔离的种类繁芜,操作不当可能造成不必要的混乱。有必要从分类、主体、程序、救济等层面加以完善,从而使个人权利和公共利益达致平衡。隔离措施的体系化以适用对象不同而展开,同时更需要对其从宪法、组织法、程序法等视角予以探讨,从而凸显政府介入风险社会之时始终注重个人权利维护的理念。 展开更多
关键词 传染病防治 隔离 检疫 宪法保留 正当程序
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IEC 61850 as Backbone for Smart PAC Systems 被引量:1
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作者 Klaus-Peter Brand 《CSEE Journal of Power and Energy Systems》 SCIE 2016年第4期15-22,共8页
This paper discusses a working definition of smartness in protection,automation and control systems(PACS)in substations.A summary is given about the standard IEC 61850 features that support smartness,i.e.,the data mod... This paper discusses a working definition of smartness in protection,automation and control systems(PACS)in substations.A summary is given about the standard IEC 61850 features that support smartness,i.e.,the data model,the multiple communication services,and the system configuration description language(SCL).With help of known examples of application functions for control,supervision,and protection,the building of smart systems out of the modules of IEC 61850 is demonstrated.From the possible architectures,the standardized redundancy is explained.The process bus is exploited in detail since it is seen by users as the core of a smart substation.In this context,attention is given also to the time synchronization in theµs range over the communication network,a rather new part of the standard.In the last part,all features are summarized and it is concluded that IEC 61850 may really be named the backbone for smart PAC systems. 展开更多
关键词 AUTOMATION communication control IEC 61850 process bus PROTECTION smart systems SUBSTATIONS
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