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Low-complexity PTS scheme based on phase factor sequences optimization 被引量:2
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作者 JI Ce ZHANG Chao ZHU Wenjing 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2018年第4期707-713,共7页
In this paper, a new partial transmit sequence(PTS)scheme with low computational complexity is proposed for the problems of high computational complexity in the conventional PTS method. By analyzing the relationship... In this paper, a new partial transmit sequence(PTS)scheme with low computational complexity is proposed for the problems of high computational complexity in the conventional PTS method. By analyzing the relationship of candidate sequences in the PTS method under the interleaved partition method, it has been discovered that some candidate sequences generated by phase factor sequences have the same peak average power ratio(PAPR). Hence, phase factor sequences can be optimized to reduce their searching times. Then, the computational process of generating candidate sequences can be simplified by improving the utilization of data and minimizing the calculations of complex multiplication. The performance analysis shows that, compared with the conventional PTS scheme, the proposed approach significantly decreases the computational complexity and has no loss of PAPR performance. 展开更多
关键词 partial transmit sequence (PTS) peak average powerratio (PAPR) phase factor sequences optimization orthogonal frequency division multiplexing (OFDM) low computational com-plexity
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An Optimal Sorting of Pulse Amplitude Sequence Based on the Phased Array Radar Beam Tasks
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作者 Chuan Sheng Yongshun Zhang Wenlong Lu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2016年第3期85-90,共6页
The study of phased array radar( PAR) pulse amplitude sequence characteristics is the key to understand the radar's working state and its beam's scanning manner.According to the principle of antenna pattern fo... The study of phased array radar( PAR) pulse amplitude sequence characteristics is the key to understand the radar's working state and its beam's scanning manner.According to the principle of antenna pattern formation and the searching and tracking modes of beams,this paper analyzes the characteristics and differences of pulse amplitude sequence when the radar beams work in searching and tracking modes respectively.Then an optimal sorting model of pulse amplitude sequence is established based on least-squares and curve-fitting methods.This method is helpful for acquiring the current working state of the radar and recognizing its instantaneous beam pointing by sorting the pulse amplitude sequence without the necessity to estimate the antenna pattern. 展开更多
关键词 phased array radar pulse amplitude sequence OPTIMAL SORTING LEAST-SQUARES and curve-fittingmethods
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Delay enhancement patterns in apical hypertrophic cardiomyopathy by phase-sensitive inversion recovery sequence 被引量:1
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作者 Zi-Yi Guo Jing Chen +6 位作者 Qi-Zhou Liang Hai-Yan Liao Shui-Xi Fu Qian-Yu Tang Cai-Xiang Chen Xiang-Jun Han Feng Gao 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2012年第10期828-830,共3页
Objective:Late gadolinium enhancement(LGE) patterns of cardiovascular magnetic resonance (CMR) relying on PSIR(phase-sensitive inversion recovery sequence) techniques had been used to determine the characteristics of ... Objective:Late gadolinium enhancement(LGE) patterns of cardiovascular magnetic resonance (CMR) relying on PSIR(phase-sensitive inversion recovery sequence) techniques had been used to determine the characteristics of LGE in apical hypertrophic cardiomyopathy(ApHCM). Methods:Forty patients pure ApHCM[age,(60.2±10.4) years,31 men]were enrolled.LGE images were acquired using PSIR,and analyzed using a 17-segment model.Summing the LGE areas in all short axis slices yielded the total volume of late enhancement,which was subsequently presented as a proportion of total LV myocardium(%LGE).Results:Mean maximal apical wall thickness was(17.9±2.3) mm,and mean left ventricular(LV) ejection fraction was(67.7±8.0)%.LGE was detected in 130 segments of 30 patients(75.0%),occupying(4.9±5.5)% of LV myocardium.LGE was mainly detected at the junction between left and right ventricles in 12(30%) and at the apex in 28(70%),although LGE-positive areas were widely distributed,and not limited to the apex.Focal LGE at the non-hypertrophic LV segments was found in some ApHCM patients,even without LGE of hypertrophied apical segments.Conclusions:LGE was frequently observed not only in the thickened apex of the heart but also in other LV segments,irrespective of the presence or absence of hypertrophy.The simple presence of LGE on CMR was not representative of adverse prognosis in this population. 展开更多
关键词 APICAL HYPERTROPHIC cardiomyopathy Cardiovascular magnetic resonance Late gadolinium ENHANCEMENT phase-sensitive inversion recovery sequence
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Conductor Arrangement and Phase Sequence Optimization Scheme for 500 kV Four-Circuit Transmission Lines on Same Tower
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作者 Deng Lu Xujun Lang +2 位作者 Bo Yang Ziyang Li Hang Geng 《Energy Engineering》 EI 2023年第10期2287-2306,共20页
The four-circuit parallel line on the same tower effectively solves the problems faced by the line reconstruction and construction under the condition of the increasing shortage of transmission corridors.Optimizing th... The four-circuit parallel line on the same tower effectively solves the problems faced by the line reconstruction and construction under the condition of the increasing shortage of transmission corridors.Optimizing the conductor and phase sequence arrangement of multiple transmission lines is conducive to improving electromagnetic and electrostatic coupling caused by electromagnetic problems.This paper uses the ATP-EMTP simulation software to build a 500 kV multi-circuit transmission line on the same tower.It stimulates the induced voltage and current values of different line lengths,tower spacing,vertical and horizontal spacing between different circuits,phase sequence arrangement,and nominal tower height.Moreover,use the BP neural network optimized by a genetic algorithm to predict the induced voltage and current under the unknown conductor and phase sequence arrangement.Finally,based on multi-objective particle swarm algorithm to construct the optimization model of conductor arrangement scheme of overhead transmission line,combined with electromagnetic environment control index,determine the optimal conductor arrangement scheme by the size of particle fitness function,a significant reduction in induced voltages and currents between transmission lines and the four-circuit conductor layout scheme meeting the requirements of the electromagnetic environment is obtained,which provides a reference for the tower design of the transmission station project. 展开更多
关键词 Spatial arrangement phase sequence arrangement genetic algorithm BP neural network multi-objective particle swarm algorithm
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Approach to blind estimation of the PN sequence in DS-SS signals with residual carrier 被引量:8
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作者 Tianqi Zhang Shaosheng Dai +2 位作者 Guoning Ma Wei Zhang Pu Miao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第1期1-8,共8页
This paper presents an approach of singular value de- composition plus digital phase lock loop to solve the difficult problem of blind pseudo-noise (PN) sequence estimation in low signal to noise ratios (SNR) dire... This paper presents an approach of singular value de- composition plus digital phase lock loop to solve the difficult problem of blind pseudo-noise (PN) sequence estimation in low signal to noise ratios (SNR) direct sequence spread spectrum (DS-SS) signals with residual carrier. This approach needs some given parameters, such as the period and code rate of PN sequence. The received signal is firstly sampled and divided into non-overlapping signal vectors according to a temporal window, whose duration is two periods of PN sequence. An autocorrelation matrix is then computed and accumulated by those signal vectors one by one. The PN sequence with residual carrier can be estimated by the principal eigenvector of the autocorrelation matrix. Further more, a digital phase lock loop is used to process the estimated PN sequence, it estimates and tracks the residual carrier and removes the residual carrier in the end. Theory analysis and computer simulation results show that this approach can effectively realize the PN sequence blind estimation from the input DS-SS signals with residual carrier in lower SNR. 展开更多
关键词 direct sequence spread spectrum (DS-SS) signal pseudo-noise (PN) sequence blind estimation singular value de-composition digital phase lock loop residual carrier.
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FAREY SEQUENCE OF NONLINEAR DIFFERENTIAL DYNAMIC SYSTEM IN TWO DIMENSIONS 被引量:1
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作者 H. Q. Jin and S. N. Xu Shenyang Institute of Technology , Shenyang 110015 , China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1999年第5期1234-1236,共3页
In this paper , through the discrim ination of Farey sequence in the forced Brusselator withweak coupling , it is proved that there is a topological translation fro m a nonlinear differen tial system ( limit cycle)... In this paper , through the discrim ination of Farey sequence in the forced Brusselator withweak coupling , it is proved that there is a topological translation fro m a nonlinear differen tial system ( limit cycle) to the circle m ap . 展开更多
关键词 non - linearity Farey sequence phase lock CHAOS
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Transformation Sequence Rule of Martensite Plates and Temperature Memory Effect in Shape Memory Alloys 被引量:1
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作者 Tian-Wei Liu Yan-Jun Zheng Li-Shan Cui 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2015年第10期1286-1290,共5页
In thermoelastic martensitic transformation, it is well established that the first martensite plate appearing upon cooling becomes the final one during reverse transformation to austenite upon heating. The results obt... In thermoelastic martensitic transformation, it is well established that the first martensite plate appearing upon cooling becomes the final one during reverse transformation to austenite upon heating. The results obtained from this work show that the transformation sequence of the martensite appears to be random. Newly formed martensite plates can modify the elastic strain energy level stored in the already existing martensite. Additionally, the elastic strain energy stored in newly formed martensite is not necessarily to be higher than the remaining martensite. The obtained results may assist in understanding phenomena related to partial transformation of shape memory alloys, such as temperature memory effect. 展开更多
关键词 phase transformation Shape memory alloys TEM Transformation sequence
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Low dimensional chaos in the AT and GC skew profiles of DNA sequences
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作者 周茜 陈增强 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第9期268-273,共6页
This paper investigates the existence of low-dimensional deterministic chaos in the AT and GC skew profiles of DNA sequences. It has taken DNA sequences from eight organisms as samples. The skew profiles are analysed ... This paper investigates the existence of low-dimensional deterministic chaos in the AT and GC skew profiles of DNA sequences. It has taken DNA sequences from eight organisms as samples. The skew profiles are analysed using continuous wavelet transform and then nonlinear time series methods. The invariant measures of correlation dimension and the largest Lyapunov exponent are calculated. It is demonstrated that the AT and GC skew profiles of these DNA sequences all exhibit low dimensional chaotic behaviour. It suggests that chaotic properties may be ubiquitous in the DNA sequences of all organisms. 展开更多
关键词 CHAOS phase space reconstruction DNA sequences AT and GC skew profiles
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High efficiency spreading spectrum modulation using double orthogonal complex sequences
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作者 Shi Xiaohong 《Engineering Sciences》 EI 2012年第5期71-75,共5页
This paper presents a novel scheme of high efficiency spreading spectrum modulation using double orthogonal complex sequences (DoCS). In this scheme, input data bit-stream is split into many groups with length M. Ea... This paper presents a novel scheme of high efficiency spreading spectrum modulation using double orthogonal complex sequences (DoCS). In this scheme, input data bit-stream is split into many groups with length M. Each group is then mapped into a word of width M and then utihzed to select one sequence from 2u-2 DoCS sequences each with length L. After that, the selected sequence is modulated on carrier in quadrature phase shift keying (QPSK) mode. In addition, a new method named forward phase correction (FPC) is put forward for carrier recovery. Theoretical analysis and bit-error-ratio(BER) experiment results indicate that the proposed scheme has better performance than the conventional direct sequence spread spectrum(DSSS) scheme both in bandwidth efficiency and processing gain of the receiver. 展开更多
关键词 modulation and demodulation high efficiency spreading spectrum modulation forward phase correction double orthogonal complex sequences
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High-Pressure Phase Transitions and Mechanisms in Lanthanum Mononitride
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作者 Hao Chen Dan Zhou +1 位作者 Ying Xu Quan Li 《Chinese Physics Letters》 2025年第6期163-169,共7页
A longstanding discrepancy between theoretical predictions and experimental observations on the highpressurestructural transformations of lanthanum mononitride(LaN)has posed challenges for understandingthe behavior of... A longstanding discrepancy between theoretical predictions and experimental observations on the highpressurestructural transformations of lanthanum mononitride(LaN)has posed challenges for understandingthe behavior of heavy transition metal mononitrides.Here,we systematically investigate the structural evolutionof LaN under high pressure using first-principles calculations combined with angle-dispersive synchrotron X-raydiffraction,identifying the phase transition sequence and corresponding phase boundaries.Analyses of energetics,kinetic barriers,and lattice dynamics reveal distinct mechanisms driving these transitions.These results clarifythe structural stability of LaN and offer guidance for studying other heavy transition metal mononitrides withcomplex electronic behavior under extreme conditions. 展开更多
关键词 phase transition sequence understandingthe behavior heavy transition metal mononitridesherewe high pressure phase transitions lanthanum mononitride theoretical predictions lattice dynamics structural stability lanthanum mononitride lan
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考虑电感不对称的LFSPM电动机无位置传感器控制与分析
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作者 杜怿 孙可 《江苏大学学报(自然科学版)》 北大核心 2026年第1期64-70,共7页
针对特有的纵向端部效应导致直线电动机三相电感不对称、使得无位置传感器控制位置和速度估计误差中出现交流分量的问题,以一台直线磁通切换永磁(linear flux switched permanent magnet,LFSPM)电动机为对象,提出一种基于二阶陷波器的... 针对特有的纵向端部效应导致直线电动机三相电感不对称、使得无位置传感器控制位置和速度估计误差中出现交流分量的问题,以一台直线磁通切换永磁(linear flux switched permanent magnet,LFSPM)电动机为对象,提出一种基于二阶陷波器的改进型锁相环(phase-locked loop,PLL).首先,建立考虑电感不对称的LFSPM电动机数学模型,基于静止坐标系设计滑模观测器,分析得出电感不对称会使扩展反电动势含正负序分量,导致PLL位置误差出现交流分量且无法被常规PI控制器抑制,并从理论上解释改进PLL抑制位置误差交流分量的原理;其次,基于MATLAB/Simulink搭建了LFSPM电动机无位置传感器控制系统仿真模型,对采用常规和改进型PLL无位置传感器控制效果进行讨论;最后,搭建试验平台并对提出的控制策略进行测试.结果表明:相比于常规无位置控制方法,所提出的基于二阶陷波器的改进型PLL方案可有效提升LFSPM电动机无位置传感器控制精度,将速度误差减小了35.71%,位置误差减小了44.46%,推力脉动减小了12%. 展开更多
关键词 直线磁通切换永磁电动机 无传感器控制 电感不对称 二阶陷波器 滑模观测器 纵向端部效应 锁相环 正负序分量
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基于多维度的大曲关键风味代谢菌群判定与调控应用研究
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作者 胡金喆 韩业慧 +3 位作者 谌琦月 尚贝贝 杜海 徐岩 《食品与发酵工业》 北大核心 2026年第1期366-375,I0020-I0024,共15页
该研究通过顶空固相微萃取-气相色谱-质谱联用技术(headspace-solid phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS)和高通量测序技术系统解析了3种大曲的特征香气化合物及微生物群落结构。研究发现,3种... 该研究通过顶空固相微萃取-气相色谱-质谱联用技术(headspace-solid phase microextraction-gas chromatography-mass spectrometry,HS-SPME-GC-MS)和高通量测序技术系统解析了3种大曲的特征香气化合物及微生物群落结构。研究发现,3种大曲分为以吡嗪类或以酯类化合物为主体风味两类。采用多元统计分析并根据变量投影重要性指标(variable importance in the projection,VIP)分析共鉴定出31种特征香气化合物。利用高通量测序技术对大曲的细菌群落结构进行解析,结合相关性分析,从多个维度判定了其核心微生物为火山渣芽孢杆菌属(Scopulibacillus)和芽孢杆菌属(Bacillus),其与多种吡嗪类、酚类、醇类等特征风味物质显著相关。通过分离培养及固态发酵实验探究其风味代谢能力,核心微生物的应用结果表明大曲细菌菌群的生物量及吡嗪类化合物的含量明显提升,改变了大曲的香气组成,进一步证实了其对大曲主体风味的调控功能。该研究在实现大曲风味定向调控、提升白酒品质方面具有重要意义。 展开更多
关键词 高通量测序 顶空固相微萃取-气相色谱-质谱联用 相关性分析 核心微生物 特征香气化合物 大曲风味调控
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Stable and metastable phase equilibria in binary Mg-Gd system: A comprehensive understanding aided by CALPHAD modeling 被引量:10
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作者 Huaijia Si Yuxun Jiang +1 位作者 Ying Tang Lijun Zhang 《Journal of Magnesium and Alloys》 SCIE 2019年第3期501-513,共13页
In this paper,a comprehensive understanding of stable and metastable phase equilibria in binary Mg-Gd system was conducted with an aid of the CALculation of PHAse Diagram(CALPHAD)modeling.Firstly,thermodynamic descrip... In this paper,a comprehensive understanding of stable and metastable phase equilibria in binary Mg-Gd system was conducted with an aid of the CALculation of PHAse Diagram(CALPHAD)modeling.Firstly,thermodynamic descriptions of all the stable phases in the Mg-Gd system were re-assessed by considering all the experimental data in the literature.The discrepancy between the phase equilibria and thermochemical properties existing in the previous assessments was eliminated,and the better agreement with the experimental data was achieved in the present assessment.Secondly,the Gibbs energies for metastable β"-Mg3Gd and β"-Mg7Gd were constructed based on the first-principles and CALPHAD computed results as well as their correlation,and then incorporated into the CALPHAD descriptions.The model-predicted solvuses of(Mg)in equilibrium with the metastable β"-Mg7Gd and β'-Mg7Gd compounds showed very good agreement with the limited experimental data.Finally,the presently obtained thermodynamic descriptions of both stable and metastable phases in the binary Mg-Gd system were further validated by realizing the quantitative Scheil-Gulliver solidification simulations of 5 as-cast Mg-Gd alloys,and the successful prediction of the precipitation sequences in Mg-15Gd and Mg-12Gd alloys during the aging process. 展开更多
关键词 Mg-Gd system phase equilibria Metastable phase CALPHAD Precipitation sequence
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Phase Transitions Governed by the Fifth Power of the Golden Mean and Beyond 被引量:6
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作者 Hans Hermann Otto 《World Journal of Condensed Matter Physics》 2020年第3期135-158,共24页
In this contribution results from different disciplines of science were compared to show their intimate interweaving with each other having in common the golden ratio <span style="font-family:Verdana;">... In this contribution results from different disciplines of science were compared to show their intimate interweaving with each other having in common the golden ratio <span style="font-family:Verdana;">φ<span style="font-family:Verdana;"> respectively its fifth power <span style="font-family:Verdana;">φ<sup><span style="font-family:Verdana;">5</sup><span style="font-family:Verdana;">. The research fields cover model calculations of statistical physics associated with phase transitions, the quantum probability of two particles, new physics of everything suggested by the information relativity theory (<span style="font-family:Verdana;">IRT<span style="font-family:Verdana;">) including explanations of cosmological relevance, the <span style="font-family:Verdana;">ε<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">-<span style="font-family:;" "=""><span style="font-family:Verdana;">infinity theory, superconductivity, and the <span style="font-family:Verdana;">Tammes<span style="font-family:Verdana;"> problem of the largest diameter of <span style="font-family:Verdana;">N<span style="font-family:Verdana;"> non-overlapping circles on the surface of a sphere with its connection to viral morphology and crystallography. Finally, <span style="font-family:Verdana;">Fibo<span style="font-family:Verdana;">nacci<span style="font-family:Verdana;"> anyons proposed for topological quantum<span style="font-family:Verdana;"> computation (<span style="font-family:Verdana;">TQC<span style="font-family:Verdana;">) were briefly described in comparison to the recently formulated reverse <span style="font-family:Verdana;">Fibonacci<span style="font-family:Verdana;"> approach using the <span style="font-family:Verdana;">Jani<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="white-space:nowrap;">&#269;ko<span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> number sequence. An architecture applicable for a quantum computer is proposed consisting of 13-step twisted microtubules similar to tubulin microtubules of living matter. Most topics point to the omnipresence of the golden mean as the numerical dominator of our world. 展开更多
关键词 Golden Mean phase Transitions Hard-Hexagon Respectively Hard-Square Gas Model Quantum Probability Information Relativity Theory (IRT) ε-Infinity Theory Superconductivity Tammes Problem Viral Morphology Helical Microtubules Janičko Number sequence Topological Quantum Computation Fibonacci Lattice CRYSTALLOGRAPHY
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Intelligent power factor compensation equipment of three phase low voltage loads 被引量:1
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作者 罗安 董密 +1 位作者 Richard Dzudzor 《Journal of Central South University of Technology》 2002年第1期64-69,共6页
An intelligent power factor correction scheme is presented for three phase low power factor loads. This new scheme is able to perform individual phase sensing of parameters by monitoring at all times to sense a change... An intelligent power factor correction scheme is presented for three phase low power factor loads. This new scheme is able to perform individual phase sensing of parameters by monitoring at all times to sense a change in system parameters and affects individual phase correction by applying the exact amount of reactive components needed for each phase, and can also reduce negative sequence current caused by the load to improve system balance. An optimization criterion is used for the proper calculation of reactive power steps in a power compensation installation of capacitor banks. The criterion is enabled by sampling measurements performed on the electrical plant examined within specific interval of time. 展开更多
关键词 power factor correction individual phase sensing negative sequence current system balance
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Fast speedometer identification in dynamic scene based on phase correlation 被引量:1
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作者 王昱棠 付梦印 杨毅 《Journal of Beijing Institute of Technology》 EI CAS 2012年第3期394-399,共6页
Speedometer identification has been researched for many years.The common approaches to that problem are usually based on image subtraction,which does not adapt to image offsets caused by camera vibration.To cope with ... Speedometer identification has been researched for many years.The common approaches to that problem are usually based on image subtraction,which does not adapt to image offsets caused by camera vibration.To cope with the rapidity,robust and accurate requirements of this kind of work in dynamic scene,a fast speedometer identification algorithm is proposed,it utilizes phase correlation method based on regional entire template translation to estimate the offset between images.In order to effectively reduce unnecessary computation and false detection rate,an improved linear Hough transform method with two optimization strategies is presented for pointer line detection.Based on VC++ 6.0 software platform with OpenCV library,the algorithm performance under experiments has shown that it celerity and precision. 展开更多
关键词 speedometer dynamic scene image sequence phase correlation improved linear Hough transform
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ANALYSIS OF SPECTRAL PHASE ENCODING OCDMA SYSTEM WITH PSEUDORANDOM CODING 被引量:2
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作者 张海滨 宋文涛 +1 位作者 黄培中 李荣玉 《Journal of Shanghai Jiaotong university(Science)》 EI 2002年第1期1-3,共3页
Multiple access interference (MAI) is the most serious interference in spectral phase encoding optical code division multiple access (SPE OCDMA) systems. This paper focuses on the behavior of MAI in SPE OCDMA systems ... Multiple access interference (MAI) is the most serious interference in spectral phase encoding optical code division multiple access (SPE OCDMA) systems. This paper focuses on the behavior of MAI in SPE OCDMA systems with pseudorandom coding. The statistical expectation of multi access interference (MAI) is derived and plotted. The results confirm that MAI can be suppressed effectively by pseudorandom coding with m sequences. 展开更多
关键词 optical CODE-DIVISION MULTIPLE-ACCESS (OCDMA) SPECTRAL phase encoding M-sequenceS MULTIPLE-ACCESS inteference (MAI)
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Study Hybrid Compensation Cophase Traction Power Supply System Schemes for High-Speed and Heavy Haul Electrical Railway with V Connection Transformer
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作者 Yankun Xia Qunzhan Li +3 位作者 Yuanzhe Zhao Xiaohan Liu Hao Wu Yang Zhou 《Energy and Power Engineering》 2013年第4期534-539,共6页
In order to solve negative phase sequence problem of V connection transformer in the high speed and heavy haul electrical railway of China, the hybrid compensative co-phase traction power supply system which based on ... In order to solve negative phase sequence problem of V connection transformer in the high speed and heavy haul electrical railway of China, the hybrid compensative co-phase traction power supply system which based on passive and active compensation is proposed. Firstly, There construction and capacity distribution are analyzed, and the compensation current of active equipment is gave;Second, the feature of the hybrid compensative schemes are discussed. In the end, the related simulation results have confirmed the effectiveness of the compensation schemes in this paper. 展开更多
关键词 V CONNECTION TRANSFORMER HYBRID COMPENSATION Negative phase sequence Cophase Power Supply System
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Binary Phase Shaping and SHG Contrast Ratios
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作者 Tingyao Xiong 《Journal of Applied Mathematics and Physics》 2024年第8期3026-3035,共10页
Finding binary sequences with Large SHG ratios is very important in the field of ultrafast science, biomedical optics, high-resolution microscopy and label-free imaging. In this paper, we have demonstrated the relatio... Finding binary sequences with Large SHG ratios is very important in the field of ultrafast science, biomedical optics, high-resolution microscopy and label-free imaging. In this paper, we have demonstrated the relation between the SHG contrast ratio and the traditional Merit Factor values. And in the light from known results in Merit Factor Problems, we have shown that Legendre Sequences or Jacobi Sequences, are still the best candidates to obtain binary sequences with large SHG contrast ratios. The authors also discussed the SHG behaviors on some sequences obtained from cyclotomic classes over the finite field GF (2l) . 展开更多
关键词 Binary phase Shaping Binary sequences SHG Contrast Ratio Merit Factor
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Mn元素对Al-Si-Cu-Mg合金富铁相形貌及力学性能的影响 被引量:1
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作者 李萌 相志磊 +2 位作者 李雷哲 谷欣硕 陈子勇 《铸造》 2025年第4期479-486,共8页
在Al9Si1Cu0.5Mg0.15Fe合金中添加不同含量的Mn元素,研究Mn元素添加量对合金中富铁相形貌、尺寸及合金性能的影响;同时从热力学角度探讨了添加不同含量Mn元素后合金中α-Fe相的形成温度与富铁相形貌之间的关系。结果表明:随着Mn元素含... 在Al9Si1Cu0.5Mg0.15Fe合金中添加不同含量的Mn元素,研究Mn元素添加量对合金中富铁相形貌、尺寸及合金性能的影响;同时从热力学角度探讨了添加不同含量Mn元素后合金中α-Fe相的形成温度与富铁相形貌之间的关系。结果表明:随着Mn元素含量的增加,富铁相形貌的演变顺序为:针状→汉字状、棒状→汉字状、粒状→树枝状、粒状→梅花状、树枝状。Mn的最佳添加量为0.4%,此时合金中α-Fe相的形成温度与α(Al)基体的结晶温度相近,富铁相以细小的汉字状均匀分布在合金中。经统计,富铁相的平均尺寸随Mn含量的增加先减小再增大,Mn添加量为0.4%时,富铁相的平均尺寸最小,面积分数相较于未添加Mn时增加的较少;合金中富铁相长径比为1的占比为40%,且长径比分布较为集中;合金塑性达到了7.99%,相较于未添加Mn元素的合金提高了104.9%。 展开更多
关键词 AL-SI-CU-MG合金 富Fe相 演变顺序 显微组织 力学性能
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