期刊文献+
共找到164篇文章
< 1 2 9 >
每页显示 20 50 100
The UK Education System and References for China
1
作者 李欢欢 《海外英语》 2011年第15期288-289,298,共3页
The UK education has a long history and is internationally accepted for its qualifications and teaching standards. This essay firstly gives an introduction about the development of British education since the last cen... The UK education has a long history and is internationally accepted for its qualifications and teaching standards. This essay firstly gives an introduction about the development of British education since the last century, then discusses the basic structure of British education system and finally suggests some references for our education. 展开更多
关键词 The UK EDUCATION SYSTEM the DEVELOPMENT of BRITISH EDUCATION references for China
在线阅读 下载PDF
General coarsened measurement references for revelation of a classical world
2
作者 谢东 徐春玲 王安民 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第11期133-137,共5页
It has been found that for a fixed degree of fuzziness in the coarsened references of measurements,the quantum-toclassical transition can be observed independent of the macroscopicity of the quantum state.We explore a... It has been found that for a fixed degree of fuzziness in the coarsened references of measurements,the quantum-toclassical transition can be observed independent of the macroscopicity of the quantum state.We explore a general situation that the degree of fuzziness can change with the rotation angle between two states(different rotation angles represent different references).The fuzziness of reference comes from two kinds of fuzziness:the Hamiltonian(rotation frequency)and the timing(rotation time).For the fuzziness of the Hamiltonian alone,the degree of fuzziness for the reference will change with the rotation angle between two states,and the quantum effects can still be observed with any degree of fuzziness of Hamiltonian.For the fuzziness of timing,the degree of the coarsening reference is unchanged with the rotation angle.During the rotation of the measurement axis,the decoherence environment can also help the classical-to-quantum transition due to changing the direction of the measurement axis. 展开更多
关键词 fuzziness rotation Hamiltonian references unitary timing comes unchanged alone operators
在线阅读 下载PDF
Comparison between English and Chinese Repeated References to the Same Thing and Parallel Structure
3
作者 赵丽红 《海外英语》 2013年第11X期259-261,共3页
Chinese and English are two very different languages; the former belongs to the Sino-Tibetan Language Family and the latter the Indo-European Language Family. In terms of textual organization, they show substantial di... Chinese and English are two very different languages; the former belongs to the Sino-Tibetan Language Family and the latter the Indo-European Language Family. In terms of textual organization, they show substantial differences. Chinese is mainly a pragmatic, paratactic and topic-prominent language, while English a grammatical, hypotactic and subject-prominent language. This thesis gives a contrastive study of two problems in English and Chinese. They are repeated references to the same thing and parallel structure. In this way, the translation work will be more succinct and smooth. 展开更多
关键词 DIFFERENCES in ENGLISH and CHINESE repeated refere
在线阅读 下载PDF
Fine-grained grid computing model for Wi-Fi indoor localization in complex environments
4
作者 Yan Liang Song Chen +1 位作者 Xin Dong Tu Liu 《Journal of Electronic Science and Technology》 EI CAS CSCD 2024年第1期42-52,共11页
The fingerprinting-based approach using the wireless local area network(WLAN)is widely used for indoor localization.However,the construction of the fingerprint database is quite time-consuming.Especially when the posi... The fingerprinting-based approach using the wireless local area network(WLAN)is widely used for indoor localization.However,the construction of the fingerprint database is quite time-consuming.Especially when the position of the access point(AP)or wall changes,updating the fingerprint database in real-time is difficult.An appropriate indoor localization approach,which has a low implementation cost,excellent real-time performance,and high localization accuracy and fully considers complex indoor environment factors,is preferred in location-based services(LBSs)applications.In this paper,we proposed a fine-grained grid computing(FGGC)model to achieve decimeter-level localization accuracy.Reference points(RPs)are generated in the grid by the FGGC model.Then,the received signal strength(RSS)values at each RP are calculated with the attenuation factors,such as the frequency band,three-dimensional propagation distance,and walls in complex environments.As a result,the fingerprint database can be established automatically without manual measurement,and the efficiency and cost that the FGGC model takes for the fingerprint database are superior to previous methods.The proposed indoor localization approach,which estimates the position step by step from the approximate grid location to the fine-grained location,can achieve higher real-time performance and localization accuracy simultaneously.The mean error of the proposed model is 0.36 m,far lower than that of previous approaches.Thus,the proposed model is feasible to improve the efficiency and accuracy of Wi-Fi indoor localization.It also shows high-accuracy performance with a fast running speed even under a large-size grid.The results indicate that the proposed method can also be suitable for precise marketing,indoor navigation,and emergency rescue. 展开更多
关键词 Fine-grained grid computing (FGGC) Indoor localization Path loss Random forest Reference points(RPs)
在线阅读 下载PDF
Equalization Reconstruction Algorithm Based on Reference Signal Frequency Domain Block Joint for DTMB-Based Passive Radar
5
作者 Shuai Ma Zeqi Yang +2 位作者 Hua Zhang Yiheng Liu Xiaode Lyu 《Journal of Beijing Institute of Technology》 EI CAS 2024年第1期41-53,共13页
Channel equalization plays a pivotal role within the reconstruction phase of passive radar reference signals.In the context of reconstructing digital terrestrial multimedia broadcasting(DTMB)signals for low-slow-small... Channel equalization plays a pivotal role within the reconstruction phase of passive radar reference signals.In the context of reconstructing digital terrestrial multimedia broadcasting(DTMB)signals for low-slow-small(LSS)target detection,a novel frequency domain block joint equalization algorithm is presented in this article.From the DTMB signal frame structure and channel multipath transmission characteristics,this article adopts a unconventional approach where the delay and frame structure of each DTMB signal frame are reconfigured to create a circular convolution block,facilitating concurrent fast Fourier transform(FFT)calculations.Following equalization,an inverse fast Fourier transform(IFFT)-based joint output and subsequent data reordering are executed to finalize the equalization process for the DTMB signal.Simulation and measured data confirm that this algorithm outperforms conventional techniques by reducing signal errors rate and enhancing real-time processing.In passive radar LSS detection,it effectively suppresses multipath and noise through frequency domain equalization,reducing false alarms and improving the capabilities of weak target detection. 展开更多
关键词 passive radar frequency domain equalization reference signal reconstruction digital terrestrial multimedia broadcasting(DTMB)
在线阅读 下载PDF
气象观测场在汽车试验场中的应用研究
6
作者 陈海建 《时代汽车》 2024年第14期172-174,178,共4页
汽车试验场作为汽车开展道路测试的重要场所,用于验证汽车产品的品质以及可靠性。除了场地道路外,气象条件作为汽车道路测试的重要一环,在《GB/T12534-1990汽车道路试验方法通则》中也有明确要求,如:试验时应是无雨无雾天气,相对湿度小... 汽车试验场作为汽车开展道路测试的重要场所,用于验证汽车产品的品质以及可靠性。除了场地道路外,气象条件作为汽车道路测试的重要一环,在《GB/T12534-1990汽车道路试验方法通则》中也有明确要求,如:试验时应是无雨无雾天气,相对湿度小于95%,气温0-40℃,风速不大于3m/s。同时气象条件也作为试验场道路管控的重要依据,实时风速、雨量、能见度等信息为场地管理者发布限速、限行、封场等通知提供必要参考依据,直接影响道路测试安全管控的及时性。因此,文章从气象观测场的建设、气象服务、异常天气道路管控等方面开展气象观测场在汽车试验场中的应用研究。 展开更多
关键词 汽车试验场 气象服务 道路管控 products. In addition to the SITE roads METEOROLOGICAL conditions are an important part of AUTOMOTIVE ROAD testing and there are also clear requirements in the GB/T12534-1990 General Rules for AUTOMOTIVE ROAD Test Methods. For example the test should be conducted in rain and fog free weather with a relative humidity of less than 95% a temperature of 0-40 and a wind SPEED of no more than 3m/s. At the same time METEOROLOGICAL conditions also serve as an important basis for ROAD control in the test site. Real time information such as wind SPEED rainfall and visibility provides necessary reference for SITE managers to issue notices on SPEED limits SITE closures and traffic restrictions directly affecting the timeliness of ROAD testing safety control. Therefore this article conducts research on the application of METEOROLOGICAL observation SITES in AUTOMOTIVE testing SITES from the construction of METEOROLOGICAL observation SITES METEOROLOGICAL services and abnormal weather ROAD control.
在线阅读 下载PDF
柔性XML文档的实现
7
作者 刘文华 《安阳师范学院学报》 2004年第2期60-61,共2页
介绍了实现柔性XML的两种方法:用entityreferences简化XML文档和用parameterentities实现XML文档的复用。通过entityreferences和parameterentities的使用我们可以创建更加结构化的XML文档,更好地组织数据,同时也可以时代码的运行效率... 介绍了实现柔性XML的两种方法:用entityreferences简化XML文档和用parameterentities实现XML文档的复用。通过entityreferences和parameterentities的使用我们可以创建更加结构化的XML文档,更好地组织数据,同时也可以时代码的运行效率更高。 展开更多
关键词 柔性XML DTD ENTITY references PARAMETER entities
在线阅读 下载PDF
Patent Citations Analysis and Its Value in Research Evaluation: A Review and a New Approach to Map Technology-relevant Research 被引量:14
8
作者 Anthony F.J. van Raan 《Journal of Data and Information Science》 CSCD 2017年第1期13-50,共38页
Purpose: First, to review the state-of-the-art in patent citation analysis, particularly characteristics of patent citations to scientific literature (scientific non-patent references, SNPRs). Second, to present a ... Purpose: First, to review the state-of-the-art in patent citation analysis, particularly characteristics of patent citations to scientific literature (scientific non-patent references, SNPRs). Second, to present a novel mapping approach to identify technology-relevant research based on the papers cited by and referring to the SNPRs. Design/methodology/approach: In the review part we discuss the context of SNPRs such as the time lags between scientific achievements and inventions. Also patent-to-patent citation is addressed particularly because this type of patent citation analysis is a major element in the assessment of the economic value of patents. We also review the research on the role of universities and researchers in technological development, with important issues such as universities as sources of technological knowledge and inventor-author relations. We conclude the review part of this paper with an overview of recent research on mapping and network analysis of the science and technology interface and of technological progress in interaction with science. In the second part we apply new techniques for the direct visualization of the cited and citing relations of SNPRs, the mapping of the landscape around SNPRs by bibliographic coupling and co-citation analysis, and the mapping of the conceptual environment of SNPRs by keyword co-occurrence analysis. Findings: We discuss several properties of SNPRs. Only a small minority of publications covered by the Web of Science or Scopus are cited by patents, about 3%-4%. However, for publications based on university-industry collaboration the number of SNPRs is considerably higher, around 15%. The proposed mapping methodology based on a "second order SNPR approach" enables a better assessment of the technological relevance of research. Research limitations: The main limitation is that a more advanced merging of patent and publication data, in particular unification of author and inventor names, in still a necessity. Practical implications: The proposed mapping methodology enables the creation of a database of technology-relevant papers (TRPs). In a bibliometric assessment the publications of research groups, research programs or institutes can be matched with the TRPs and thus the extent to which the work of groups, programs or institutes are relevant for technological development can be measured. Originality/value: The review part examines a wide range of findings in the research of patent citation analysis. The mapping approach to identify a broad range of technologyrelevant papers is novel and offers new opportunities in research evaluation practices. 展开更多
关键词 Patent citations Scientific non-patent references Inventor-author relations Bibliometric mapping Science and technology interface Research evaluation Technologyrelevant publications
在线阅读 下载PDF
MODEL REFERENCE ADAPTIVE CONTROL BASED ON NONLINEAR COMPENSATION FOR TURBOFAN ENGINE 被引量:4
9
作者 潘慕绚 黄金泉 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第3期215-221,共7页
The design of a turbofan rotor speed control system, using model reference adaptive control(MRAC) method with input and output measurements, is discussed for the purpose of practical application. The nonlinear compe... The design of a turbofan rotor speed control system, using model reference adaptive control(MRAC) method with input and output measurements, is discussed for the purpose of practical application. The nonlinear compensator based on functional link neural network is used to deal with the engine nonlinearity and the hardware-in-loop simulation is also developed. The results show that the nonlinear MRAC controller has the adequate performance of compensating and adapting nonlinearity arising from the change of engine state or working environment. Such feature demonstrates potential practical applications of MRAC for aeroengine control system. 展开更多
关键词 turbofan engin model reference adaptive control(MRAC) functional link neural network (FLNN) hardware-in-loop(HIL) simulation
在线阅读 下载PDF
DIRECT SELF-REPAIRING CONTROL FOR HELICOPTER VIA QUANTUM CONTROL AND ADAPTIVE COMPENSATOR 被引量:1
10
作者 陈复扬 姜斌 陶钢 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2011年第4期337-342,共6页
A direct self-repairing control approach is proposed for helicopter via quantum control techniques and adaptive compensator when some complex faults occur. For a linear varying-parameter helicopter control system, the... A direct self-repairing control approach is proposed for helicopter via quantum control techniques and adaptive compensator when some complex faults occur. For a linear varying-parameter helicopter control system, the model reference adaptive control law is designed and an adaptive compensator is used for improving its self-re- pairing capability. To enhance anti-interference capability of helicopter, quantum control feedforward is added be- tween fault and disturbance. Simulation results illustrate the effectiveness and feasibility of the approach. 展开更多
关键词 HELICOPTER model reference adaptive control self-repairing control quantum control
在线阅读 下载PDF
Reference 3D、ASTER DEM精度检测与对比分析 被引量:1
11
作者 张霄 陈楚江 余绍淮 《中外公路》 北大核心 2011年第1期9-12,共4页
Reference 3D是法国Spot立体卫星影像生成的DEM,ASTER DEM是高分辨率卫星成像设备——ASTER获取的立体影像生成的DEM,它们全球覆盖范围广、数据获取快、质量稳定。针对中国缺乏1∶10 000或1∶5 000基础地形资料的地区、难以获取资料的... Reference 3D是法国Spot立体卫星影像生成的DEM,ASTER DEM是高分辨率卫星成像设备——ASTER获取的立体影像生成的DEM,它们全球覆盖范围广、数据获取快、质量稳定。针对中国缺乏1∶10 000或1∶5 000基础地形资料的地区、难以获取资料的海外交通建设地区,采用这两种方法检测其精度,并对比分析其在公路勘察设计中的应用。工程实践表明:Reference 3D相比ASTER DEM有着更高的精度,质量更加稳定可靠,可以满足公路勘察设计中规划、工可等阶段的需要,从而提高工作效率,缩短外业周期,降低成本。 展开更多
关键词 REFERENCE 3D ASTER DEM 精度 公路 勘察设计
在线阅读 下载PDF
Applicahon of a Simplified Model Reference Adaptive Algorithm 被引量:1
12
作者 王丽艳 宫小东 +1 位作者 金志立 曹泛 《Journal of Beijing Institute of Technology》 EI CAS 1994年第1期90+82-90,共10页
The application of a simplifed model reference adaptive control(SMRAC) on a typical Pump controlled motor electrohydraulic servo system is studied here. The algorithm of first-order scalar SMRAC ac second-order vector... The application of a simplifed model reference adaptive control(SMRAC) on a typical Pump controlled motor electrohydraulic servo system is studied here. The algorithm of first-order scalar SMRAC ac second-order vector SMRAC are derived. Computer simulations of the algorithms are presented. Experimental results prove that the method of control adopted here perform satisfactorily over a wide range of operating conditions. 展开更多
关键词 model reference adaptive control digital control electrohydraulic servo system
在线阅读 下载PDF
Correction to:Bottomonium suppression in heavy‑ion collisions and the in‑medium strong force 被引量:2
13
作者 Ralf Rapp 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2023年第5期85-85,共1页
Correction to:NUCL SCI TECH(2023)34:63 https://doi.org/10.1007/s41365-023-01213-3 While typesetting,reference[16]in the list has not been properly placed in the proof.The orders of the references[13-16]were mistaken b... Correction to:NUCL SCI TECH(2023)34:63 https://doi.org/10.1007/s41365-023-01213-3 While typesetting,reference[16]in the list has not been properly placed in the proof.The orders of the references[13-16]were mistaken by the production.The correct order of the references is. 展开更多
关键词 PROPERLY ORDERS references
在线阅读 下载PDF
Model Reference Variable Structure Autopilot Design for Homing Missile 被引量:1
14
作者 宋建梅 《Journal of Beijing Institute of Technology》 EI CAS 2001年第4期364-369,共6页
To design the control system for some homing missile so that the autopilot can transfer guidance command correctly and be robust to disturbances, such as the measurement noises and parameter variation caused by areody... To design the control system for some homing missile so that the autopilot can transfer guidance command correctly and be robust to disturbances, such as the measurement noises and parameter variation caused by areodynamic floating. The model reference adaptive control was combined with the variable structure control to design a model reference variable structure (MRVS) control system whose control structure is simple and can be realized easily. The simulation results indicate that MRVS can complete the task of transferring guidance command and suppress the distrubances effectively. 展开更多
关键词 model reference variable structure variable structure control AUTOPILOT
在线阅读 下载PDF
COMPARISON AND EVALUATION OF CURRENT REFERENCE GENERATION STRATEGIES FOR ACTIVE POWER FILTERS IN THREE-PHASE FOUR-WIRE SYSTEMS
15
作者 陈东华 郭涛 +1 位作者 谢少军 周波 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第4期298-306,共9页
For three phase four-wire active power filters (APFs), several typical power theories and corresponding current reference generation strategies are induced, p-q, d-q, unify power factor (UPF) and instantaneous act... For three phase four-wire active power filters (APFs), several typical power theories and corresponding current reference generation strategies are induced, p-q, d-q, unify power factor (UPF) and instantaneous active current (IAC) methods are analyzed and compared with each other. The interpretation of active and reactive currents in non-sinusoidal and unbalanced three-phase four-wire systems is given based on the generalized instantaneous reactive power theory. The performance and the characteristic are evaluated, and the application conditions of current reference generation strategies are concluded. Simulation results under different source voltages and loads verify the evaluation result. 展开更多
关键词 active power filters instantaneous reactive power current reference three-phase four wire power
在线阅读 下载PDF
核动力设备无信息先验研究
16
作者 郭海宽 赵新文 +3 位作者 蔡琦 张永发 黄丽琴 邢晋 《兵器装备工程学报》 CAS 2016年第5期139-143,共5页
故障时间数据服从单参数情形下使用Jeffreys先验可以得到很好的推断结果,但对于服从双参数的情形,并且参数之间具有相关性时,需要对Jeffreys先验作特定的修改才能使用;推导出服从正态分布的核动力设备故障时间的Jeffreys先验和Referenc... 故障时间数据服从单参数情形下使用Jeffreys先验可以得到很好的推断结果,但对于服从双参数的情形,并且参数之间具有相关性时,需要对Jeffreys先验作特定的修改才能使用;推导出服从正态分布的核动力设备故障时间的Jeffreys先验和Reference先验,通过分析它们的后验频率性质得到:Reference先验πR(μ,σ~2)∞1/σ~2是σ~2的精确概率匹配先验、μ的二阶概率匹配先验;在Jeffreys先验下,σ~2水平为α的可信上限的频率覆盖概率低于事先给定的可信水平α,其差异会随着样本容量的增大而逐渐缩小;对实例进行分析,首先推导出核动力设备泵的正态分布故障时间数据的Reference无信息先验,应用此先验对故障时间数据进行分析,然后通过Bayesianχ~2拟合优度对所建立的无信息先验模型进行检验,发现仅有15.5%的R^B超过0.95分位数,表明所建立的正态分布Reference无信息先验模型可以很好的描述本实例中核动力设备泵的故障时间数据。 展开更多
关键词 核动力设备 Reference先验 Jeffreys先验 概率安全评价
在线阅读 下载PDF
Application of Fuzzy Modification Strategy in MRAC
17
作者 王丽艳 金志立 曹泛 《Journal of Beijing Institute of Technology》 EI CAS 1995年第1期72+67-72,共7页
Based on a simplified model reference adaptive control(SMRAC) algorithm a parameter modification algorithm according to fuzzy laws is proposed in this paper. The method makes the adaptive parameters in SMRAC only rely... Based on a simplified model reference adaptive control(SMRAC) algorithm a parameter modification algorithm according to fuzzy laws is proposed in this paper. The method makes the adaptive parameters in SMRAC only rely on the status of performance error. Thus it eliminates the influences of gain coefficients in SMRAC and the amplitude of input signal on the dynamic characteristics. Experiments on various step amplitudes and loads show that the performances of SMRAC are improved by incorporating fuzzy modification method. 展开更多
关键词 model reference adaptive control process control electrohydraulic servo system/fuzzy modification
在线阅读 下载PDF
DECENTRALIZED ADAPTIVE CONTROL FOR LINEAR TIME INVARIENT SYSTEMS WITH FIRST ORDER INTERCONNECTIONS
18
作者 黄金泉 孙健国 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 1999年第1期80-85,共6页
A new decentralized adaptive control scheme is presented for linear time invariant systems with first order interconnections. The proposed control scheme with “proportional plus integral” terms is used to improve ... A new decentralized adaptive control scheme is presented for linear time invariant systems with first order interconnections. The proposed control scheme with “proportional plus integral” terms is used to improve the convergence rate and the ultimate bound of the tracking error. It is important to note that the adaptive scheme uses lower adaptive gains and smaller control inputs to avoid input saturation and oscillatory behavior. Simulation results are illustrated for controlling a dual inverted pendulum and a multivariable turbofan engine using the proposed adaptive scheme. These simulations validate out conclusions. 展开更多
关键词 decentralized control model reference adaptive control control law numerical simulation
在线阅读 下载PDF
具有一般协方差结构的增长曲线模型的reference先验(英文)
19
作者 何道江 许凯 《应用概率统计》 CSCD 北大核心 2014年第1期57-71,共15页
Reference分析最早由Bernardo(1979)提出的,Berger和Bernardo(1992a)做了进一步的发展.而Berger等(2001)提出了一个获得精确reference先验的方法,它已经成为获取无信息先验的最成功的方法之一.本文基于Berger等(2001)所提出的的算法,研... Reference分析最早由Bernardo(1979)提出的,Berger和Bernardo(1992a)做了进一步的发展.而Berger等(2001)提出了一个获得精确reference先验的方法,它已经成为获取无信息先验的最成功的方法之一.本文基于Berger等(2001)所提出的的算法,研究了具有一般协方差结构的增长曲线模型的reference先验.同时,给出了相应结果的一些应用. 展开更多
关键词 Reference先验 增长曲线模型 线性混合模型 组内相关系数
在线阅读 下载PDF
A Critical Evaluation on College English Reference Books for Teachers 被引量:1
20
作者 刘富华 《海外英语》 2013年第19期94-95,共2页
The present paper points out the problems and defects existing in college English reference books in China.Further more,measures for improvement are suggested and the need for such improvement is also analyzed.Finally... The present paper points out the problems and defects existing in college English reference books in China.Further more,measures for improvement are suggested and the need for such improvement is also analyzed.Finally,through a case study,an improved version of college English reference books is presented and concluded. 展开更多
关键词 COLLEGE ENGLISH REFERENCE BOOKS problems and defec
在线阅读 下载PDF
上一页 1 2 9 下一页 到第
使用帮助 返回顶部