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Modeling of Ad-hoc and Infrastructure Dual Mode Mobile Networks 被引量:1
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作者 Hui-Nien Hung 《International Journal of Automation and computing》 EI 2005年第1期75-84,共10页
This paper investigates a mobile telecommunications system that supports both ad hoc and infrastructure mode operations. Based on analytic and simulation models, our study investigates how base station (BS) and ad hoc... This paper investigates a mobile telecommunications system that supports both ad hoc and infrastructure mode operations. Based on analytic and simulation models, our study investigates how base station (BS) and ad hoc channel capacity, and the mobility and locality of mobile stations affect the performance of a dual mode system. We show that a dual mode system can significantly outperform a single mode (infrastructure) system when the degree of locality is high. Furthermore, a dual mode system can support much faster mobile users with less BS channels in comparison to an infrastructure mode system. Our study quantitatively identifies the threshold value for the number of ad hoc channels such that beyond this threshold, increasing ad hoc channel capacity will not improve the performance of a dual mode system. Keywords Ad-hoc - infrastructure - dual mode system Yi-Hung Chen received B.S. degree in 2001 and M.S. degree in 2003 of Computer Science and Information Engineering from National Chiao Tung University, HsinChu, Taiwan. He is an engineer of QUALCOMM CDMA technologies Taiwan.His research interests include wireless communication and ad-hoc networking.Hui-Nien Hung received the B.S. degree in mathematics from the National Taiwan University, Taipei, Taiwan, in 1989, the M.S. in mathematics degree from National Tsin-Hua University, Hsinchu, Taiwan, in 1991, and the Ph.D. degree in statistics from the University of Chicago, Chicago, IL, in 1996. He is a Professor at the Institute of Statistics, National Chiao Tung University, Taiwan.His current research interests include applied probability, financial calculus, bioinformatics, statistical inference, statistical computing, and industrial statistics. Yi-Bing Lin (M’96-SM’96-F’04) is Chair Professor and Vice President of Research and Development, National Chiao Tung University.His current research interests include wireless communications and mobile computing Dr. Lin has published over 190 journal articles and more than 200 conference papers. His current research interests include wireless communications and mobile computing Dr. Lin has published over 190 journal articles and more than 200 conference papers. Lin is coauthor of the book Wireless and Mobile Network Architecture (with Imrich Chlamtac; published by John Wiley & Sons). Lin is an IEEE Fellow, an ACM Fellow, an AAAS Fellow, and an IEE Fellow. 展开更多
关键词 AD-HOC INFRASTRUCTURE dual mode system
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DUAL MODE WIDEBAND BAND-PASS FILTER WITH NOTCHED BAND FOR COMMUNICATION SYSTEM
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作者 Wang Hui Yang Guo Wu Wen Ge Sheng 《Journal of Electronics(China)》 2011年第4期444-449,共6页
This paper presents a planar microstrip wideband dual mode Band-Pass Filter(BPF) from 2 GHz to 3.4 GHz with a notched band at 2.62 GHz.The dual mode band-pass filter consists of a ring resonator with two quarter-wavel... This paper presents a planar microstrip wideband dual mode Band-Pass Filter(BPF) from 2 GHz to 3.4 GHz with a notched band at 2.62 GHz.The dual mode band-pass filter consists of a ring resonator with two quarter-wavelength open-circuited stubs at =90o and =0o,respectively.A square perturbation stub has been put at the corner of the ring resonator to increase the narrow stopbands and improve the performance of selectivity.By using a parallel-coupled feed line,a narrow notched band is introduced at the required frequency and its Fractional BandWidth(FBW) is about 5%.The proposed filter has a narrow notched band and a wide pass-band with a sharp cutoff frequency characteristic,the attenuation rate for the sharp cutoff frequency responses is 297.17 dB/GHz(cal-culated from 1.959 GHz with-34.43 dB to 2.065 GHz with-2.93 dB) and 228.10 dB/GHz(calculated from 3.395 GHz with-2.873 dB to 3.507 GHz with-28.42 dB).This filter has the advantages of good insertion loss in both operating bands and two rejections of greater than 16 dB in the range of 1.59 GHz to 1.99 GHz and 3.49 GHz to 3.98 GHz.Having been presented in this article,the measurement results agree well with the simulation results,which validates our idea. 展开更多
关键词 Communication system Band-Pass Filter(BPF) dual mode Notched band
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Dual Mode-Multiple Output SEPIC Converter Integrated with Passive Ripple Cancelling Circuit for Standalone PV Energy Harvesting System
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作者 Sharmin Sobhan Md. Ashraful Hoque +2 位作者 Golam Sarowar Tanvir Ahmad Abdul Mannan Farhan 《Journal of Power and Energy Engineering》 2016年第11期1-18,共18页
This document addresses an exhaustive standalone Photovoltaic (PV) energy harvesting system considering two crucial issues: system efficiency and cost effectiveness. It contributes a compact resolution with a combined... This document addresses an exhaustive standalone Photovoltaic (PV) energy harvesting system considering two crucial issues: system efficiency and cost effectiveness. It contributes a compact resolution with a combined feature of Dual Mode-Multiple Output (DMMO) associated with input ripple reduction technique. Control strategy incorporates with aspect of Maximum Power Point Tracking (MPPT) and output voltage levels regulation. A theoretical analysis is conducted to evaluate the effect of ripple current on PV power. Proposed dual mode converter achieves efficiency of 98.36% and 97.76% respectively for mode-1 and mode-2 operation. However, simulation is performed applying MATLAB/SIMULINK tools to analyze the feasibility of the recommended system. 展开更多
关键词 Photovoltaic Cell Current Ripple Reduction dual mode Converter Multiple Outputs Efficiency
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A Dual Mode Dielectric Resonator and Its Design to Bandpass Filter
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作者 游彬 姬五胜 +1 位作者 王学东 李英 《Journal of Shanghai University(English Edition)》 CAS 2003年第1期76-79,共4页
In this paper, the resonant frequency of a dual\|mode dielectric resonator is calculated using a finite difference time\|domain method. A new type of bandpass filter is designed with the calculated coupling coefficien... In this paper, the resonant frequency of a dual\|mode dielectric resonator is calculated using a finite difference time\|domain method. A new type of bandpass filter is designed with the calculated coupling coefficient. The filter designed in this paper has reached the design goal, verified by simulation with Ansoft HFSS. 展开更多
关键词 dual\|mode dielectric resonator bandpass filter finite\|difference time\|domain.
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基于Dual-Mode MCMA+DD双模式盲均衡算法研究 被引量:5
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作者 郭元术 岳蕾 姚博彬 《光子学报》 EI CAS CSCD 北大核心 2009年第10期2702-2706,共5页
为了兼顾误差性能和收敛速度,研究了将双模修正常量模算法和判决引导算法有机结合的双模式盲均衡算法.该算法在收敛初期采用双模修正常量模算法调整均衡器,然后根据判决条件自动切换到判决引导算法,最终实现信道的盲均衡.仿真结果表明:... 为了兼顾误差性能和收敛速度,研究了将双模修正常量模算法和判决引导算法有机结合的双模式盲均衡算法.该算法在收敛初期采用双模修正常量模算法调整均衡器,然后根据判决条件自动切换到判决引导算法,最终实现信道的盲均衡.仿真结果表明:此算法收敛速度快、稳态误差小,并能在去除码间干扰的同时纠正信道固有的相位旋转,具有很好的实用性. 展开更多
关键词 盲均衡 常量模算法 双模式盲均衡算法 修正常量模算法
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Theory of annual runoff evolution under natural-artificial dual mode and case study of Wuding River basin on the middle Yellow River 被引量:8
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作者 WANG Hao WANG Chengming +2 位作者 WANG Jianhua ZHOU Zuhao CHEN Yiming 《Science China(Technological Sciences)》 SCIE EI CAS 2004年第z1期51-59,共9页
Water cycling process in a river basin becomes more complicated because of the intensified impact by human activities. Study of the law of annual runoff evolution in a river basin is of great significance to quantitat... Water cycling process in a river basin becomes more complicated because of the intensified impact by human activities. Study of the law of annual runoff evolution in a river basin is of great significance to quantitative analysis of the water resources condition in varied environment and prediction of the law of the water resources evolution in the future because year-based time span may best reflect the law of the water resources evolution driven by the nature and human activities in the river basin. This paper advances the theory of annual runoff evolution under natural-artificial dual mode based on the dual mode of the water resources evolution, and the theory is applied for the Wuding River Basin on the middle Yellow River as a case study. A thorough analysis of the precipitation-runoff relationship is made in the case of dynamic variation of ground surface conditions of the Wuding River basin, and the concept of water-soil conservation index area that indicates adoption of various measures for water and soil conservation to reflect ground surface conditions. Furthermore, precipitation-runoff empirical model is developed to reflect dynamic variation of the ground surface conditions of the river basin. The study may lay a solid foundation for the integrated theoretical platform of the law of the water resources evolution in the Yellow River basin and the dual model of the evolution. 展开更多
关键词 annual runoff dual mode water resources variation evolution theory Wuding River.
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Analysis of flow-field in a dual mode ramjet combustor with boundary layer bleed in isolator 被引量:2
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作者 Nishanth Thillai Amit Thakur +1 位作者 Srikrishnateja K. Dharani J. 《Propulsion and Power Research》 SCIE 2021年第1期37-47,共11页
A two-dimensional Reynolds averaged Navier Stokes(RANS)simulation of a dual mode ramjet(DMRJ)combustor is performed,modeling the University of Michigan dual-mode combustor experimental setup operating in reacting mode... A two-dimensional Reynolds averaged Navier Stokes(RANS)simulation of a dual mode ramjet(DMRJ)combustor is performed,modeling the University of Michigan dual-mode combustor experimental setup operating in reacting mode with different equivalence ratios(4).The simulations are carried out using a k-u SST turbulence model and a steady diffusion flamelet model for non-premixed combustion.Air enters the isolator at Mach 2.2,stagnation pressure and temperature of 549.2 kPa and 1400 K respectively.Hydrogen is injected transverse to the flow direction and upstream of the cavity flame holder to simulate ramjet(4 Z 0.29)and scramjet(4 Z 0.19)modes of operation.Wall static pressure plots are used to validate numerical results against experimental data.Analysis of flow separation in ramjet mode due to the presence of a shock train in the isolator is carried out by means of numerical Schlieren images overlapped with contours of negative axial velocity,showing the effects of shock wave boundary layer interaction(SWBLI).Active control through wall normal boundary layer bleed in the separated flow region is implemented,which weakens the shock train and moves it downstream closer to the cavity.Bleed results in an improved stagnation pressure recovery in ramjet mode,with a marginal increase in combustion efficiency. 展开更多
关键词 dual mode ramjet Scramjet combustor Shock wave boundary layer interaction Boundary-layer bleed Flamelet combustion model
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The Conceptual Design Experience of Sea-Going Ships with Alternative Propulsion System, Equipped with Dual-Mode Contra Propeller
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作者 Anatolij-Branko R. Togunjac Leonid I. Vishnevsky Evgeniy A. Sedykh 《Journal of Shipping and Ocean Engineering》 2016年第2期105-109,共5页
The paper presents a technical solution which provides energy saving at full speed, as well as duplication of screw propeller and main propulsion system incase it's out of order. The description of the corresponding ... The paper presents a technical solution which provides energy saving at full speed, as well as duplication of screw propeller and main propulsion system incase it's out of order. The description of the corresponding device, designed for transport refrigerator ship, is shown as well as its location on board. Value of energy saving from the use of contra propeller is estimated. The results of the assessment required power to move the ship at low speed by the action of the contra propeller operating in the reactive mode are demonstrated. It is shown, that the ship equipped with the proposed device will get the additional class notation related to the redundancy or duplication of the propulsion system of Russian Maritime Register of Shipping. 展开更多
关键词 Alternative propulsion system dual mode contra propeller multipurpose propulsor.
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基于Dual-Mode MMA+MDD双模式T/2分数间隔盲均衡算法的研究 被引量:1
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作者 柳雷 赖惠成 贾振红 《光子学报》 EI CAS CSCD 北大核心 2011年第6期898-901,共4页
均衡技术是用来解决通信系统中码间干扰的常用方法.针对传统恒模算法的收敛速度和稳态剩余码间干扰大的缺点,将双模式多模算法和改进型判决引导算法结合起来,并且应用于分数间隔盲均衡器中.该算法初期用双模式算法收敛均衡器,然后切换... 均衡技术是用来解决通信系统中码间干扰的常用方法.针对传统恒模算法的收敛速度和稳态剩余码间干扰大的缺点,将双模式多模算法和改进型判决引导算法结合起来,并且应用于分数间隔盲均衡器中.该算法初期用双模式算法收敛均衡器,然后切换到改进型判决引导算法中进一步收敛,由于分数间隔均衡器解决了波特间隔均衡器因抽样率不高带来的频谱混叠问题,从而进一步地提高了均衡效果.蒙特卡罗仿真表明,该算法不仅收敛速度快,而且得到较低的剩余码间干扰. 展开更多
关键词 恒模算法 盲均衡 分数间隔 双模式多模算法
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Dual-mode Nonlinear MPC via Terminal Control Laws With Free-parameters 被引量:7
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作者 Defeng He 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第3期526-533,共8页
The paper presents a new dual-mode nonlinear model predictive control(NMPC) scheme for continuous-time nonlinear systems subject to constraints on the state and control.The idea of control Lyapunov functions for nonli... The paper presents a new dual-mode nonlinear model predictive control(NMPC) scheme for continuous-time nonlinear systems subject to constraints on the state and control.The idea of control Lyapunov functions for nonlinear systems is used to compute the terminal regions and terminal control laws with some free-parameters in the dual-mode NMPC framework.The parameters of the terminal controller are selected offline to estimate the terminal region as large as possible;and the parameters are optimized online to gain optimality of the terminal controller with respect to given cost functions.Then a dual-mode NMPC algorithm with varying time-horizon is formulated for the constrained system.Recursive feasibility and closed-loop stability of this NMPC are established.The example of a spring-cart is used to demonstrate the advantages of the presented scheme by comparing to the dual-mode NMPC via the linear quadratic regulator(LQR) method. 展开更多
关键词 Constrained control dual-mode control model predictive control nonlinear control
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Analysis Method and Principle of Dual-mode Electro-mechanical Variable Transmission Program 被引量:6
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作者 LI Hongcai YAN Qingdong +1 位作者 XIANG Changle WANG Weida 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第3期524-529,共6页
Automotive industry,as an important pillar of the national economy,has been rapidly developing in recent years.But proplems such as energy comsumption and environmental pollution are posed at the same time.Electro-mec... Automotive industry,as an important pillar of the national economy,has been rapidly developing in recent years.But proplems such as energy comsumption and environmental pollution are posed at the same time.Electro-mechanical variable transmission system is considered one of avilable workarounds.It is brought forward a kind of design methods of dual-mode electro-mechanical variable transmission system rotational speed characteristics and dual-mode drive diagrams.With the motor operating behavior of running in four quadrants and the speed characteristics of the simple internal and external meshing single planetary gear train,four kinds of dual-mode electro-mechanical transmission system scheme are designed.And the velocity,torque and power characteristics of one of the programs are analyzed.The magnitude of the electric split-flow power is an important factor which influences the system performance,so in the parameters matching design,it needs to reduce the power needs under the first mode of the motor.The motor,output rotational speed range and the position of the mode switching point have relationships with the characteristics design of the planetary gear set.The analysis method is to provide a reference for hybrid vehicles' design.As the involved rotational speed and torque relationships are the natural contact of every part of transmission system,a theory basis of system program and performance analysis is provided. 展开更多
关键词 electro-mechanical variable transmission dual-mode rotational speed characteristics
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Facile Approach to Synthesize Gold Nanorod@Polyacrylic Acid/Calcium Phosphate Yolk–Shell Nanoparticles for Dual-Mode Imaging and pH/NIR-Responsive Drug Delivery 被引量:4
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作者 Guilan Li Yidan Chen +5 位作者 Lingyu Zhang Manjie Zhang Shengnan Li Lu Li Tingting Wang Chungang Wang 《Nano-Micro Letters》 SCIE EI CAS 2018年第1期63-73,共11页
A facile strategy to fabricate gold nanorod@polyacrylic acid/calcium phosphate(Au NR@-PAA/Ca P) yolk–shell nanoparticles(NPs) composed with a PAA/Ca P shell and an Au NR yolk is reported. The asobtained Au NR@PAA/Ca ... A facile strategy to fabricate gold nanorod@polyacrylic acid/calcium phosphate(Au NR@-PAA/Ca P) yolk–shell nanoparticles(NPs) composed with a PAA/Ca P shell and an Au NR yolk is reported. The asobtained Au NR@PAA/Ca P yolk–shell NPs possess ultrahigh doxorubicin(DOX) loading capability(1 mg DOX/mg NPs), superior photothermal conversion property(26%)and p H/near-infrared(NIR) dual-responsive drug delivery performance. The released DOX continuously increased due to the damage of the Ca P shell at low p H values. When the DOX-loaded Au NR@PAA/Ca P yolk–shell NPs wereexposed to NIR irradiation, a burst-like drug release occurs owing to the heat produced by the Au NRs. Furthermore,Au NR@PAA/Ca P yolk–shell NPs are successfully employed for synergic dual-mode X-ray computed tomography/photoacoustic imaging and chemo-photothermal cancer therapy. Therefore, this work brings new insights for the synthesis of multifunctional nanomaterials and extends theranostic applications. 展开更多
关键词 Yolk–shell structure Calcium phosphate dual-mode imaging Photothermal therapy Drug delivery
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NOVEL COMPOSITE CVT SYSTEMS WITH DIVERGING AND DUAL-MODE CONVERGING POWER FLOW 被引量:2
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作者 Liu Shudao Huang Xiangdong +1 位作者 Zhao Kegang Luo Yutao College of Traffic & Communications,South China University of Technology,Guangzhou 510640, China 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2004年第2期257-262,共6页
A new type of composite CVT(continuously variable transmission) systemsfeatured by power flow divergence and dual-mode convergence, capable of improving CVT's efficiencyand power capacity or making AMTs(automated ... A new type of composite CVT(continuously variable transmission) systemsfeatured by power flow divergence and dual-mode convergence, capable of improving CVT's efficiencyand power capacity or making AMTs(automated manual transmissions) become continuously variable, isstudied. With specific mechano-mechanical and electromechanical composite CVT systems as detailedexamples, its basic working principles are expatiated. General methods and key points in designingand realizing such systems are also analyzed and discussed. 展开更多
关键词 Composite CVT Planetary gear set dual-mode power convergence
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Magnetically-coated silica nanospheres for dual-mode imaging at low ultrasound frequency 被引量:1
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作者 Fernanda Chiriacò Giulia Soloperto +4 位作者 Antonio Greco Francesco Conversano Andrea Ragusa Luca Menichetti Sergio Casciaro 《World Journal of Radiology》 CAS 2013年第11期411-420,共10页
AIM: To experimentally investigate the acoustical behavior of different dual-mode nanosized contrast agents(NPCAs) for echographic medical imaging at low ultrasound(US) frequency. METHODS: We synthesized three differe... AIM: To experimentally investigate the acoustical behavior of different dual-mode nanosized contrast agents(NPCAs) for echographic medical imaging at low ultrasound(US) frequency. METHODS: We synthesized three different nanosized structures:(1) Pure silica nanospheres(SiNSs);(2) FePt-iron oxide(FePt-IO)-coated SiNSs; and(3) IOcoated SiNSs, employing three different diameter of SiNS-core(160, 330 and 660 nm). Tissue mimicking phantoms made of agarose gel solution containing 5 mg of different NPCAs in 2 mL-Eppendorf tubes, were insonified by a commercial echographic system at three different low US pulse values(2.5, 3.5 and 4.5 MHz). The raw radiofrequency signal, backscattered from each considered NPCA containing sample, has been processed in order to calculate the US average backscatter intensity and compare the acoustic behavior of the different NPCA types. RESULTS: The highest US contrast was exhibited by pure SiNSs; FePt-IO-coated SiNSs acoustical behavior followed a similar trend of pure SiNSs with a slight difference in terms of brightness values. The acoustic response of the examined NPCAs resulted function of both SiNS diameter and US frequency. Specifically, higher US frequencies determined higher value of the backscatter for a given SiNS diameter. Frequencydependent enhancement was marked for pure SiNSs and became less remarkable for FePt-IO-coated SiNSs, whereas IO-coated SiNSs resulted almost unaffected by such frequency variations. Pure and FePt-IO-coated SiNSs evidenced an image backscatter increasing with the diameter up to 330 nm. Conversely, among the types of NPCA tested, IO-coated SiNSs showed the lowest acoustical response for each synthesized diameter and employed US frequency, although a diameter-dependent raising trend was evidenced. CONCLUSION: The US characterization of magnetically covered SiNS shows that FePt-IO, rather than IO, was the best magnetic coating for realizing NPCAs suitable for dual mode imaging of deep organs, combining US and magnetic resonance imaging. 展开更多
关键词 ULTRASOUND Magnetic resonance NANOCOMPOSITE dual-mode IMAGING CONTRAST agent Diagnostic IMAGING
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Mode switching control strategy of dual motors coupled driving on electric vehicles 被引量:3
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作者 张承宁 武小花 +1 位作者 王志福 田真 《Journal of Beijing Institute of Technology》 EI CAS 2011年第3期394-398,共5页
Based on analyzing the structure and working principle on electric vehicles (EVs) with dual motors coupled by planetarY gears, the control strategy of mode switching was proposed. The power interruption problem on E... Based on analyzing the structure and working principle on electric vehicles (EVs) with dual motors coupled by planetarY gears, the control strategy of mode switching was proposed. The power interruption problem on EVs with automatic mechanical transmission (AMT) shifting was resolved. Based on the speed-torque characteristics of the planetary gears and the principle of the auxiliary motor' s zero speed braking, control features of mode switching were introduced. The mode shifting between the main motor mode and dual motors coupled driving were studied. Matlab/Simulink was adopted as a platform to develop the simulation model of EVs with dual motors drive system and 3 gears AMT. Simulation results demonstrated that the power interruption of dual motors drive system was solved during mode switching. The power requirements of EVs were satisfied, too. 展开更多
关键词 dual motors coupled driving mode switching control strategy
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Review of low timing jitter mode-locked fiber lasers and applications in dual-comb absolute distance measurement 被引量:9
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作者 Haosen Shi Youjian Song +6 位作者 Runmin Li Yuepeng Li Hui Cao Haochen Tian Bowen Liu Lu Chai Minglie Hu 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2018年第4期205-217,共13页
Passively mode-locked fiber lasers emit femtosecond pulse trains with excellent short-term stability. The quantum-limited timing jitter of a free running femtosecond erbium-doped fiber laser working at room temperatur... Passively mode-locked fiber lasers emit femtosecond pulse trains with excellent short-term stability. The quantum-limited timing jitter of a free running femtosecond erbium-doped fiber laser working at room temperature is considerably below one femtosecond at high Fourier frequency. The ultrashort pulse train with ultralow timing jitter enables absolute time-of-flight measurements based on a dual-comb implementation, which is typically composed of a pair of optical frequency combs generated by femtosecond lasers. Dead-zone-free absolute distance measurement with sub-micrometer precision and kHz update rate has been routinely achieved with a dual-comb configuration, which is promising for a number of precision manufacturing applications, from large step-structure measurements prevalent in microelectronic profilometry to three coordinate measurements in large-scale aerospace manufacturing and shipbuilding. In this paper, we first review the sub-femtosecond precision timing jitter characterization methods and approaches for ultralow timing jitter mode-locked fiber laser design. Then, we provide an overview of the state-of-the-art dual-comb absolute ranging technology in terms of working principles, experimental implementations, and measurement precisions. Finally, we discuss the impact of quantum-limited timing jitter on the dual-comb ranging precision at a high update rate. The route to highprecision dual-comb range finder design based on ultralow jitter femtosecond fiber lasers is proposed. 展开更多
关键词 TIMING JITTER mode-LOCKED lasers dual-comb ABSOLUTE distance measurement
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Engine performance analysis and optimization of a dual-mode scramjet with varied inlet conditions
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作者 Lu Tian Li-Hong Chen +2 位作者 Qiang Chen Feng-Quan Zhong Xin-Yu Chang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2016年第1期75-82,共8页
A dual-mode scramjet can operate in a wide range of flight conditions. Higher thrust can be generated by adopting suitable combustion modes. Based on the net thrust, an analysis and preliminary optimal design of a ker... A dual-mode scramjet can operate in a wide range of flight conditions. Higher thrust can be generated by adopting suitable combustion modes. Based on the net thrust, an analysis and preliminary optimal design of a kerosene-fueled parameterized dual-mode scramjet at a cru- cial flight Mach number of 6 were investigated by using a modified quasi-one-dimensional method and simulated annealing strategy. Engine structure and heat release distrib- utions, affecting the engine thrust, were chosen as analytical parameters for varied inlet conditions (isolator entrance Mach number: 1.5-3.5). Results show that different opti- mal heat release distributions and structural conditions can be obtained at five different inlet conditions. The highest net thrust of the parameterized dual-mode engine can be achieved by a subsonic combustion mode at an isolator entrance Mach number of 2.5. Additionally, the effects of heat release and scramjet structure on net thrust have been discussed. The present results and the developed analytical method can provide guidance for the design and optimization of high-performance dual-mode scramjets. 展开更多
关键词 dual-mode scramjet Engine performance THRUST OPTIMIZATION Heat release distribution Simulatedannealing algorithm
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Simulation of Aviation Kerosene Combustion in Dual-mode Scramjet Combustor
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作者 刘欧子 邹建锋 +1 位作者 蔡元虎 胡欲立 《Defence Technology(防务技术)》 SCIE EI CAS 2009年第2期88-94,共7页
Supersonic combustion of aviation kerosene is investigated under the flight conditions of Mach number 5 and fuel-air equivalence ratio 0.551.The trajectories of the fuel droplets and the heat/mass transfer between the... Supersonic combustion of aviation kerosene is investigated under the flight conditions of Mach number 5 and fuel-air equivalence ratio 0.551.The trajectories of the fuel droplets and the heat/mass transfer between them are simulated by means of discrete phase model(DPM).The k-ω model is chosen for turbulence closure and the non-premixed probability density function(PDF)approach is used to calculate the turbulence-chemistry interaction.The calculated wall static pressure and the total pressure loss coefficient are very close to the experiment results.The strut and cavity devices significantly increase the combustion efficiency. 展开更多
关键词 航空煤油 发动机燃烧室 超燃冲压 油燃烧 双态 仿真 概率密度函数 化学相互作用
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New Planar Dual-Mode Filters without Coupling Gaps
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作者 王学东 姬五胜 李英 《Journal of Shanghai University(English Edition)》 CAS 2004年第3期333-336,共4页
A class of new planar dual-mode filters without coupling gaps is proposed. The proposed structures use a single patch wiuhout coupling gaps. Attenuation poles can be implemented on either side of the passband by chang... A class of new planar dual-mode filters without coupling gaps is proposed. The proposed structures use a single patch wiuhout coupling gaps. Attenuation poles can be implemented on either side of the passband by changing the locations of two feed lines. By cutting two corners in the patch, two attenuation poles on both sides of passband are implemented. A novel dual-mode elliptic-function bandpass filter structure without coupling gaps is also proposed. These new filters can provide a low insertion loss and reduce uncertainty in fabrication owing to the absence of coupling gaps. 展开更多
关键词 bandpass filters attenuation pole dual-mode filters patch resonators.
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THE OPTIMAL MAGNETIZING FIELD DISTRIBUTION FOR FERRITE DUAL-MODE DEVICES
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作者 夏一维 李士根 蒋仁培 《Journal of Electronics(China)》 1989年第1期68-79,共12页
The optimal magnetizing fields of the variable polarization effects of ferrite are studied by using thecoupling-wave(cw)theory,vaiational principle and optimization techniques.Several kinds of shapes of themagnetic li... The optimal magnetizing fields of the variable polarization effects of ferrite are studied by using thecoupling-wave(cw)theory,vaiational principle and optimization techniques.Several kinds of shapes of themagnetic line of force and some valuable results of the optimal magnetizing field are given.The theoretical cal-culations are in good agreement with the experimental results. 展开更多
关键词 OPTIMAL MAGNETIZING field FERRITE dual-mode device VARIABLE POLARIZATION effects
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