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Existence of Periodic Solutions for an Output Hidden Feedback Elman Neural Network 认领
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作者 Valéry Covachev Zlatinka Covacheva 《软件工程与应用(英文)》 2020年第12期348-363,共16页
<div style="text-align:justify;"> <span style="font-family:Verdana;">We first recall the sufficient conditions for the existence of a periodic output of a modified Elman neural network ... <div style="text-align:justify;"> <span style="font-family:Verdana;">We first recall the sufficient conditions for the existence of a periodic output of a modified Elman neural network with a periodic input found by using Mawhin’s continuation theorem of coincidence degree theory. Using this result, we obtain sufficient conditions for the existence of a periodic output for an output hidden feedback Elman neural network with a periodic input. Examples illustrating these sufficient conditions are given.</span> </div> 展开更多
关键词 Elman Neural Network Periodic Input and Output Mawhin’s Continuation Theorem
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A Study on the Importance of Language Input in Second Language Acquisition(SLA) 认领
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作者 闵瑞华 《海外英语》 2020年第23期275-277,284,共4页
Input theory as a theoretical foundation in language teaching plays an important role in SLA.Though a wealth of re⁃search has been done by linguists to demonstrate the importance of language input in SLA,little has be... Input theory as a theoretical foundation in language teaching plays an important role in SLA.Though a wealth of re⁃search has been done by linguists to demonstrate the importance of language input in SLA,little has been written about the type and amount of language input for successful SLA,especially its processing model while acquiring a second language.This paper first discusses the Krashen’s input hypothesis in language learning,and then an introduction to Chaudron’s processing model of in⁃put is made.In the final part,the author explains the acquisition process based on word acquisition and grammar acquisition and concludes that in the process of acquiring a second language,the language learners reconstruct a new cognitive model by taking in consistent comprehensible language input. 展开更多
关键词 language input SLA processing model of input acquisition process
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产出导向法对中国高校外语学习者英语写作影响研究 认领
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作者 张文娟 《中国应用语言学(英文)》 2020年第3期323-341,389,共20页
为解决中国大学外语教学中的“学用分离”问题,产出导向法应运而生,其效果有待考察。本研究就一个单元教学进行了为期两周的准课堂实验,比较产出导向法与传统以课文为中心的精读教学法对学习者外语书面产出的影响,通过评价学习者产出文... 为解决中国大学外语教学中的“学用分离”问题,产出导向法应运而生,其效果有待考察。本研究就一个单元教学进行了为期两周的准课堂实验,比较产出导向法与传统以课文为中心的精读教学法对学习者外语书面产出的影响,通过评价学习者产出文本的总体质量以及语言、内容和语篇结构三个子项来检验产出导向法的教学效果。数据包括课堂教学前后实验组和对照组的写作样本,以及检测目标语言项学习效果的语言测试。结果显示:1)在总体写作质量、写作的内容和篇章结构方面,两组均未呈现明显差异;2)就语言使用而言,实验组写作中的语言得分明显高于对比组;实验组使用的单元目标语言项明显多于对比组。研究结果表明,相对精读教学法,产出导向法在促进外语学习者书面产出发展方面具有潜在优势。 展开更多
关键词 产出导向法 输入 输出 学用一体 写作
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Dynamical Analysis of a Stochastic Predator-Prey System with Lévy Noise and Impulsive Toxicant Input 认领
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作者 Xiaowan She Yuanfu Shao Taolin Zhang 《应用数学与应用物理(英文)》 2020年第9期1999-2019,共21页
This paper established a modified Leslie-Gower and Holling-type IV stochastic predator-prey model with Lévy noise and impulsive toxicant input. We study the stability in distribution of solutions by inequality te... This paper established a modified Leslie-Gower and Holling-type IV stochastic predator-prey model with Lévy noise and impulsive toxicant input. We study the stability in distribution of solutions by inequality techniques and ergodic method. By comparison method and It<span style="white-space:nowrap;">&#244;</span>’s formula, we obtain the sufficient conditions for the survival of each species. Some numerical simulations are introduced to show the theoretical results. 展开更多
关键词 Lévy Noise Impulsive Toxicant Input Comparison Method Extinction and Persistence
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Heritage Language Development: Expectations and Goals 认领
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作者 Stephen Krashen Haiyun Lu Nooshan Ashtari 《汉语教学方法与技术》 2020年第1期1-4,共4页
What should we expect from heritage language(HL)acquirers?We propose that given access to“optimal input,”we can eventually expect very high performance,native or near-native.But it won’t happen right away.It takes ... What should we expect from heritage language(HL)acquirers?We propose that given access to“optimal input,”we can eventually expect very high performance,native or near-native.But it won’t happen right away.It takes time. 展开更多
关键词 heritage language optimal input compelling input
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文章速递A Distributed Feedforward Control Method for Power Electronic Transformers 认领
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作者 Sizhao Lu Di Zhao +1 位作者 Kai Li Siqi Li 《中国电工技术学会电机与系统学报》 CSCD 2020年第4期319-328,共10页
Because of its advantages such as small size and light weight,power electronic transformers(PET)are increasingly used in power transmission and distribution systems.The traditional centralized control method requires ... Because of its advantages such as small size and light weight,power electronic transformers(PET)are increasingly used in power transmission and distribution systems.The traditional centralized control method requires each cascaded power module to communicate with the central controller through a high-speed communication link,which increases the computational and communication burden of the central controller and reduces the expandability and modularity of a PET system.In this paper,a distributed feedforward control method for a cascaded H-bridge(CHB)converter-based PET is proposed.The pulse width modulation,input current regulation,voltage balance control,power balance control,output voltage regulation and output current regulation are assigned to the distributed local controllers.Therefore,the computational and communication burden of the central controller can be significantly reduced.The number of fibers connected to the central controller can be significantly reduced.Meanwhile,the proposed control method can greatly improve the dynamic response of the load disturbance,and a smooth start-up process of the PET system can be achieved.Simulation results are given to show the effectiveness of the proposed method. 展开更多
关键词 Because of its advantages such as small size and light weight power electronic transformers(PET)are increasingly used in power transmission and distribution systems.The traditional centralized control method requires each cascaded power module to communicate with the central controller through a high-speed communication link which increases the computational and communication burden of the central controller and reduces the expandability and modularity of a PET system.In this paper a distributed feedforward control method for a cascaded H-bridge(CHB)converter-based PET is proposed.The pulse width modulation input current regulation voltage balance control power balance control output voltage regulation and output current regulation are assigned to the distributed local controllers.Therefore the computational and communication burden of the central controller can be significantly reduced.The number of fibers connected to the central controller can be significantly reduced.Meanwhile the proposed control method can greatly improve the dynamic response of the load disturbance and a smooth start-up process of the PET system can be achieved.Simulation results are given to show the effectiveness of the proposed method.Index Terms—Cascaded H-bridge(CHB)converter power electronic transformers(PET) distributed feedforward control.
浅谈压力式温度计示值误差测量结果的不确定度评定 认领
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作者 谢鹏赓 《水电与新能源》 2020年第4期20-22,29共4页
为了帮助试验人员深入了解压力式温度计的原理及作用,详细介绍了温度计示值误差测量结果的不确定度评定方法。影响压力式温度计示值误差结果的主要因素是,被检温度计的示值重复性、恒温槽温度不均匀性和恒温槽温场的波动。为了保证压力... 为了帮助试验人员深入了解压力式温度计的原理及作用,详细介绍了温度计示值误差测量结果的不确定度评定方法。影响压力式温度计示值误差结果的主要因素是,被检温度计的示值重复性、恒温槽温度不均匀性和恒温槽温场的波动。为了保证压力式温度计测量结果不确定度评定具有较高的可靠性,试验人员需要对影响评定可靠性的各种因素进行全面的分析,找出温度计示值的误差,从而确保温度计能够更好的被投入使用。 展开更多
关键词 压力式温度计 不确定度 误差测量 输入量
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Research on Input Power Testing Technology of Smart Toilet 认领
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作者 Jiaqiang Zhong 《电子研究与应用》 2020年第4期25-29,共5页
Input power is an important indicator for the safety testing of electrical and electronic products.Smart toilets have been frequently detected that the actual input power is inconsistent with the nominal power.Researc... Input power is an important indicator for the safety testing of electrical and electronic products.Smart toilets have been frequently detected that the actual input power is inconsistent with the nominal power.Research and analysis show that the accuracy of the input power measurement results of the smart toilet mainly depends on the temperature control principle and power test method of the product.This article mainly discusses the characteristics of product temperature control,the testing method of mean and peak power and its characteristics,which will provide reference for the input power test of the smart toilet,and will improve the accuracy of power measurement. 展开更多
关键词 Input power Mean power Smart toilet PID instant heating control
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A new approach for analyzing the effect of non-ideal power supply on a constant current underwater cabled system 认领
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作者 Yu-jia ZANG Yan-hu CHEN +3 位作者 Can-jun YANG De-jun LI Ze-jian CHEN Gul MUHAMMAD 《信息与电子工程前沿:英文版》 SCIE EI CSCD 2020年第4期604-614,共11页
The effect of a constant current(CC)power supply on the CC ocean observation system is a problem that once was neglected.The dynamic characteristics of the CC power supply may have great influence on the whole system,... The effect of a constant current(CC)power supply on the CC ocean observation system is a problem that once was neglected.The dynamic characteristics of the CC power supply may have great influence on the whole system,especially the voltage behavior in the event of load change.This needs to be examined.In this paper,a method is introduced to check whether the CC power supply can satisfy the dynamic requirements of the CC ocean observation system.An equivalent model to describe the non-ideal CC power supply is presented,through which the dynamic characteristics can be standardized.To verify the feasibility of this model,a minimum system of a single node in the CC ocean observation system is constructed,from which the model is derived.Focusing on the power failure problem,the output voltage responses are performed and the models are validated.Through the model,the dynamic behavior of the CC power supply is checked in a practical design. 展开更多
关键词 NON-IDEAL power supply CONSTANT current INPUT OCEAN observation SYSTEM
On Cultural Input in English Teaching of Primary School 认领
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作者 杜文文 《海外英语》 2020年第7期260-262,共3页
Cultural input cannot be separated from English teaching,which is conducive to improving students'intercultural com- munication ability, enhancing their interest in English learning and promoting their sensitivity... Cultural input cannot be separated from English teaching,which is conducive to improving students'intercultural com- munication ability, enhancing their interest in English learning and promoting their sensitivity to cultural perceptions. In primary school English teaching, teachers should follow the principles of practicality, gradualness, moderation and persistence to carry out cultural input;attach importance to the integration of cross-cultural knowledge in the routine teaching;enrich the classroom teach- ing content, and improve students'cultural literacy. 展开更多
关键词 CULTURAL INPUT primary SCHOOL English TEACHING culture TEACHING
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Input-output Efficiency of Elements of Urban Construction Land in Beijing: Empirical Analysis Based on Panel Data of Jurisdiction 认领
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作者 GU Yuekun 《景观研究:英文版》 2020年第2期49-53,56共6页
Based on the Data Envelopment Analysis method,and by using CCR and BCC model,Super Efficiency model and Malmquist model guided by input efficiency,the input-output efficiency of elements of urban construction land in ... Based on the Data Envelopment Analysis method,and by using CCR and BCC model,Super Efficiency model and Malmquist model guided by input efficiency,the input-output efficiency of elements of urban construction land in different jurisdictions of Beijing from 2005 to 2015 was studied.The results showed that there were obvious differences between input-output efficiency of elements of urban construction land in different jurisdictions of Beijing,among which the efficiency of the core area of capital,Yanqing District,Fangshan District and Huairou District was relatively high,while the efficiency of Daxing District,Fengtai District and Miyun District was relatively low.There was no obvious correlation between efficiency differentiation and location factors,which is mainly caused by whether the land use in each jurisdiction has scale effect,whether the technology is improved,whether the input is redundant and whether the output is insufficient.For the jurisdiction of inefficient land use,we should strengthen the consciousness of intensive land use,improve the technical level,appropriately reduce the redundancy of input elements,and pay attention to the output of social and ecological benefits. 展开更多
关键词 Data Envelopment Analysis Urban construction LAND INPUT and OUTPUT Effi ciency
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山东省寿光市蔬菜生产系统能值分析 认领
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作者 牟琳 王岩 +2 位作者 孙铭禹 赵天宏 马建 《沈阳农业大学学报:社会科学版》 2020年第3期369-376,共8页
利用能值分析的方法对2007~2016年山东省寿光市农业产业结构及蔬菜生产系统的能值投入、产出及能值指标进行分析,与其他城市的农业生态系统能值指标进行对比,反映了山东省寿光市蔬菜生产系统的发展趋势。结果表明:寿光市2007~2016年蔬... 利用能值分析的方法对2007~2016年山东省寿光市农业产业结构及蔬菜生产系统的能值投入、产出及能值指标进行分析,与其他城市的农业生态系统能值指标进行对比,反映了山东省寿光市蔬菜生产系统的发展趋势。结果表明:寿光市2007~2016年蔬菜生产系统的能值总投入处于下降趋势,能值总产出变化趋势为先增加后减小,2013年蔬菜产出能值达到最大值,寿光市蔬菜生产系统能值指标变化情况具有优势,但与其他城市相比,寿光市蔬菜生产系统经济投入量大,环境利用不够充分,可持续发展指数低但施加于环境的压力程度小。据此,寿光市应在发展生态农业的前提下合理利用自然资源,提高农业科技水平,增大生产率以实现寿光市蔬菜生产系统的可持续发展。 展开更多
关键词 寿光市 能值分析 蔬菜生产系统 投入 产出
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Random dynamic analysis of vertical train–bridge systems under small probability by surrogate model and subset simulation with splitting 认领
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作者 Huoyue Xiang Ping Tang +1 位作者 Yuan Zhang Yongle Li 《铁道工程科学:英文版》 2020年第3期305-315,共11页
The response of the train–bridge system has an obvious random behavior.A high traffic density and a long maintenance period of a track will result in a substantial increase in the number of trains running on a bridge... The response of the train–bridge system has an obvious random behavior.A high traffic density and a long maintenance period of a track will result in a substantial increase in the number of trains running on a bridge,and there is small likelihood that the maximum responses of the train and bridge happen in the total maintenance period of the track.Firstly,the coupling model of train–bridge systems is reviewed.Then,an ensemble method is presented,which can estimate the small probabilities of a dynamic system with stochastic excitations.The main idea of the ensemble method is to use the NARX(nonlinear autoregressive with exogenous input)model to replace the physical model and apply subset simulation with splitting to obtain the extreme distribution.Finally,the efficiency of the suggested method is compared with the direct Monte Carlo simulation method,and the probability exceedance of train responses under the vertical track irregularity is discussed.The results show that when the small probability of train responses under vertical track irregularity is estimated,the ensemble method can reduce both the calculation time of a single sample and the required number of samples. 展开更多
关键词 Train–bridge system Ensemble method Surrogate model Nonlinear autoregressive with exogenous input Subset simulation with splitting Small probability
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基于DEA视角的安徽省卫生健康事业投入与产出效率评价 认领
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作者 孙昕 邹胜男 丁宏 《安徽医学》 2020年第9期1095-1099,共5页
目的分析安徽省卫生健康事业投入与产出效率,为区域卫生健康事业发展规划提供参考。方法采用数据包络分析方法对安徽省16个市2011~2017年的卫生投入产出效率进行测算。结果 2011~2017年,皖北年均总体技术效率和纯技术效率(0.976、0.983... 目的分析安徽省卫生健康事业投入与产出效率,为区域卫生健康事业发展规划提供参考。方法采用数据包络分析方法对安徽省16个市2011~2017年的卫生投入产出效率进行测算。结果 2011~2017年,皖北年均总体技术效率和纯技术效率(0.976、0.983)均高于皖南(0.937、0.941)、皖中(0.902、0.913);皖南年均规模技术效率(0.996)高于皖北(0.993)、皖中(0.989)。结论安徽省卫生健康事业发展模式亟待转变,应继续落实落细分级诊疗,打造结构合理的高素质医疗卫生人才队伍,构建现代化公立医院管理体系。 展开更多
关键词 数据包络分析 投入 产出 效率评价
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输入、输出和互动模式下的大学英语口语教学探究 认领
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作者 陶鑫 崔晗 《科教导刊》 2020年第28期108-109,共2页
在二语习得领域中,输入、互动与输出一直是研究的一个重要课题,涉及到众多领域中,它们为外语教学提供了坚实的理论依据。本文分析了大学英语口语教学过程中存在的问题,并根据克拉申的输入假说、Swain的输出假说和Long的互动假说探究适... 在二语习得领域中,输入、互动与输出一直是研究的一个重要课题,涉及到众多领域中,它们为外语教学提供了坚实的理论依据。本文分析了大学英语口语教学过程中存在的问题,并根据克拉申的输入假说、Swain的输出假说和Long的互动假说探究适合大学英语口语的教学方法。在大学英语教学的过程中,教师要优化输入和输出,兼顾合理的语言互动,把三者充分结合,从而提高学习者口语水平。 展开更多
关键词 输入 互动 输出 大学英语 口语教学
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Relative energy zero ratio-based approach for identifying pulse-like ground motions 认领
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作者 Liu Ping Li Ning +2 位作者 Ma Hua Xie Lili Zhou Baofeng 《地震工程与工程振动:英文版》 SCIE EI CSCD 2020年第1期1-16,共16页
Pulse-like ground motions are capable of inflicting significant damage to structures. Efficient classification of pulse-like ground motion is of great importance when performing the seismic assessment in near-fault re... Pulse-like ground motions are capable of inflicting significant damage to structures. Efficient classification of pulse-like ground motion is of great importance when performing the seismic assessment in near-fault regions. In this study, a new method for identifying the velocity pulses is proposed, based on different trends of two parameters: the short-time energy and the short-time zero crossing rate of a ground motion record. A new pulse indicator, the relative energy zero ratio(REZR), is defined to qualitatively identify pulse-like features. The threshold for pulse-like ground motions is derived and compared with two other identification methods through statistical analysis. The proposed procedure not only shows good accuracy and efficiency when identifying pulse-like ground motions but also exhibits good performance for classifying records with high-frequency noise and discontinuous pulses. The REZR method does not require a waveform formula to express and fit the potential velocity pulses;it is a purely signal-based classification method. Finally, the proposed procedure is used to evaluate the contribution of pulse-like motions to the total input energy of a seismic record, which dramatically increases the seismic damage potential. 展开更多
关键词 pulse-like ground motion velocity PULSE relative ENERGY ZERO-CROSSING RATIO short-time input ENERGY shorttime ZERO CROSSING rate
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小龙潭露天矿近10年煤炭安全生产效率研究 认领
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作者 鄢洪 孙静 《露天采矿技术》 CAS 2020年第1期22-25,共4页
通过对小龙潭露天矿2008-2018年安全生产系统的投入-产出结构进行分析,构建小龙潭露天矿安全生产效率评价指标体系,测算各年安全生产效率。发现在近10年的安全生产过程中,小龙潭露天矿2018年的安全生产效率达到最佳,说明该年的投入-产... 通过对小龙潭露天矿2008-2018年安全生产系统的投入-产出结构进行分析,构建小龙潭露天矿安全生产效率评价指标体系,测算各年安全生产效率。发现在近10年的安全生产过程中,小龙潭露天矿2018年的安全生产效率达到最佳,说明该年的投入-产出结构合理,并且其投入-产出配比具有很强的推广性。而2014、2015连续2年出现效率不足的情况,对其投入-产出的各项指标详细分析,发现综合能耗量、生产人工冗余及煤岩生产总量不足是导致这2年安全生产效率损失的关键因素。其余各年的安全生产相对效率均呈现有效状态,总体来看小龙潭露天矿安全生产投入产出结构较为合理,其安全生产效率较高。 展开更多
关键词 露天矿 投入 产出 安全生产效率 数据包络分析法
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Compressive sensing based multiuser detector for massive MBM MIMO uplink 认领
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作者 SONG Wei WANG Wenzheng 《系统工程与电子技术:英文版》 SCIE EI CSCD 2020年第1期19-27,共9页
Media based modulation(MBM)is expected to be a prominent modulation scheme,which has access to the high data rate by using radio frequency(RF)mirrors and fewer transmit antennas.Associated with multiuser multiple inpu... Media based modulation(MBM)is expected to be a prominent modulation scheme,which has access to the high data rate by using radio frequency(RF)mirrors and fewer transmit antennas.Associated with multiuser multiple input multiple output(MIMO),the MBM scheme achieves better performance than other conventional multiuser MIMO schemes.In this paper,the massive MIMO uplink is considered and a conjunctive MBM transmission scheme for each user is employed.This conjunctive MBM transmission scheme gathers aggregate MBM signals in multiple continuous time slots,which exploits the structured sparsity of these aggregate MBM signals.Under this kind of scenario,a multiuser detector with low complexity based on the compressive sensing(CS)theory to gain better detection performance is proposed.This detector is developed from the greedy sparse recovery technique compressive sampling matching pursuit(CoSaMP)and exploits not only the inherently distributed sparsity of MBM signals but also the structured sparsity of multiple aggregate MBM signals.By exploiting these sparsity,the proposed CoSaMP based multiuser detector achieves reliable detection with low complexity.Simulation results demonstrate that the proposed CoSaMP based multiuser detector achieves better detection performance compared with the conventional methods. 展开更多
关键词 media BASED modulation(MBM) radio frequency(RF)mirror COMPRESSIVE sensing(CS) MULTIPLE input MULTIPLE output(MIMO) MULTIUSER detector COMPRESSIVE sampling matching pursuit(CoSaMP).
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State estimate for stochastic systems with dual unknown interference inputs 认领
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作者 Xiaoxue FENG Shuhui LI Feng PAN 《中国航空学报:英文版》 SCIE EI CAS CSCD 2020年第9期2395-2407,共13页
Stochastic system state estimation subject to the unknown interference input widely exists in many fields,such as the control,communication,signal processing,and fault diagnosis.However,the research results are mostly... Stochastic system state estimation subject to the unknown interference input widely exists in many fields,such as the control,communication,signal processing,and fault diagnosis.However,the research results are mostly limited to the stochastic system in which only the dynamic state model or the measurement model concerns the individual unknown interference input,and the state model and the measurement model are both with the same unknown interference input.State estimate of the stochastic systems where the state model and the measurement model contain dual Unknown Interference inputs(dual-UI)with different physical meanings and mathematical definitions is concerned here.Firstly,the decoupling condition with the Unknown Interference input in the State model(S-UI)is shown,which introduces the decoupled system with the adjacent Measurement concerned Unknown Interference inputs(M-UI)appearing in the state model and the measurement model.Then,through defining the Differential term of the adjacent M-UI(M-UID),the equivalent system with only M-UID in the state model is obtained.Finally,considering the design freedom of the equivalent system,the decoupling filter in the minimum mean square error sense and the adaptive minimum upper filter with different applicable conditions are represented to obtain the optimal and sub-optimal state estimate,respectively.Two simulation cases verify the effectiveness and superiority compared with the traditional methods. 展开更多
关键词 Adaptive filter Decoupling filter State estimate Stochastic system Unknown interference input
2例输入性恶性疟病例的治疗与护理体会 认领
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作者 邓积广 方玉花 +2 位作者 陆夏瑜 余水兰 田红艳 《医学动物防制》 2020年第6期605-606,610,共3页
目的分析2例输入性恶性疟病例的相关资料,为今后输入性疟疾病例的诊治提供科学依据。方法对2例病例的外出史、诊疗等资料进行收集、整理和分析。结果 2例病例有明确的外出高疟区务工及旅游史,结合病例的临床表现以及辅助检查等,确诊为... 目的分析2例输入性恶性疟病例的相关资料,为今后输入性疟疾病例的诊治提供科学依据。方法对2例病例的外出史、诊疗等资料进行收集、整理和分析。结果 2例病例有明确的外出高疟区务工及旅游史,结合病例的临床表现以及辅助检查等,确诊为输入性重症恶性疟病例。及时给予杀虫治疗,病例治愈出院。结论医疗机构对有明确的外出疟疾流行区返乡人员及时进行排查、隔离治疗及采取护理措施,避免重症甚至死亡病例的出现,保持消除疟疾成果。 展开更多
关键词 输入性 重症 恶性疟 治疗 护理体会
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