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基于二维干涉式APES算法的分布式相参阵盲DOA估计 被引量:4
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作者 朱伟 陈伯孝 《系统工程与电子技术》 EI CSCD 北大核心 2013年第2期237-243,共7页
结合干涉雷达的天线结构和二维波达方向(direction of arrival,DOA)估计方法,提出一种基于二维干涉式幅相估计的分布式相参阵盲DOA估计算法。利用二维干涉式幅相估计算法的空间谱和模型阶数选择准则获得目标个数和目标方向余弦的粗估计... 结合干涉雷达的天线结构和二维波达方向(direction of arrival,DOA)估计方法,提出一种基于二维干涉式幅相估计的分布式相参阵盲DOA估计算法。利用二维干涉式幅相估计算法的空间谱和模型阶数选择准则获得目标个数和目标方向余弦的粗估计;使用子阵间的相位中心偏移来获得目标方向余弦的精估计;针对分布孔径带来的测角模糊问题,采用双尺度解模糊算法实现分布式阵列的高精度方向估计。仿真结果验证了分布式相参阵的高精度测角性能及所提算法的有效性,也验证了分布阵DOA估计中存在基线模糊门限。 展开更多
关键词 分布参阵列 维干涉估计 解模糊 盲波达方向估计
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内混式二相流喷嘴流量特性 被引量:1
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作者 肖彬 《化学工程》 CAS CSCD 北大核心 2006年第12期28-30,共3页
结合相关理论,以水、润滑油和十二烷基硫酸钠(SDS)溶液作为液体介质,详细研究了操作参数(气液比)和液体物性(粘度、表面张力)对一种典型的内混式二相流喷嘴流量特性的影响,通过对实验数据的分析得出了一些重要结论。随着液体介质粘度的... 结合相关理论,以水、润滑油和十二烷基硫酸钠(SDS)溶液作为液体介质,详细研究了操作参数(气液比)和液体物性(粘度、表面张力)对一种典型的内混式二相流喷嘴流量特性的影响,通过对实验数据的分析得出了一些重要结论。随着液体介质粘度的增加,气液压力要随之增加,而表面张力的增加,气液压力基本上保持不变。根据大量的实验数据,回归出了内混式雾化喷嘴的液体流量系数的经验关联式。 展开更多
关键词 内混流雾化喷嘴 流量特性 气液比
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二维多相式相位信号参数估计降维算法及仿真
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作者 廖建庆 郑乃清 黄李健 《江南大学学报(自然科学版)》 CAS 2015年第5期580-584,共5页
针对滤波、相位解缠和多相式拟合法在参数估计中的局限性,提出一种二维多相式相位信号(PPS)参数估计的降维算法。通过固定二维多相式相位信号中的一个参数,将二维PPS转化为一组一维的多相式相位信号,再通过对一维多相式相位信号做滤波... 针对滤波、相位解缠和多相式拟合法在参数估计中的局限性,提出一种二维多相式相位信号(PPS)参数估计的降维算法。通过固定二维多相式相位信号中的一个参数,将二维PPS转化为一组一维的多相式相位信号,再通过对一维多相式相位信号做滤波和相位解缠等计算处理,最终实现对二维PPS的参数估计;另外,还对该算法的复杂度进行了简单分析。为了验证该算法在高信噪比条件下的有效性,实验采用一个三阶二维PPS的三角式信号模型,仿真结果表明该算法的参数估计均方误差达到Cramér-Rao下界。 展开更多
关键词 维多位信号 位解缠 参数优化 均方误差
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反倾销的跨国实证分析——基于宏观经济因素对反倾销立案影响的理解 被引量:6
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作者 赵晓霞 《商业经济与管理》 CSSCI 北大核心 2007年第11期56-62,共7页
基于15个国家1995-2004年反倾销的统计数据,通过模型分析以及实证研究,表明宏观经济因素对反倾销立案存在显著影响。依据GDP增长率、失业率、汇率及经常项目差额等相关数据,指出这些变量与反倾销立案数量显著相关,强调失业率的影响... 基于15个国家1995-2004年反倾销的统计数据,通过模型分析以及实证研究,表明宏观经济因素对反倾销立案存在显著影响。依据GDP增长率、失业率、汇率及经常项目差额等相关数据,指出这些变量与反倾销立案数量显著相关,强调失业率的影响比GDP增长率更加显著。在发展中国家中,汇率对反倾销立案数量影响的显著性较低,而经常项目差额对反倾销立案数量影响的显著性较高。文章的分析在一定程度上给政府制定反倾销政策提供了相关参考价值。 展开更多
关键词 宏观经济因素 反倾销 固定效应回归模型 二相式回归模型
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含硫气井产能分析方法研究 被引量:1
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作者 李琰 李晓平 《西南石油大学学报(自然科学版)》 CAS CSCD 北大核心 2007年第S2期43-45,171,共4页
含硫气藏分布广,储量大,但含硫气藏由于硫的存在,在生产开发过程中产生硫沉积,极大地破坏气井产能,因而含硫气井产能一直备受关注。一点法,修正等时试井法等常规试井方法和分析理论是否仍适用于含硫气井目前还缺乏理论依据。基于渗流力... 含硫气藏分布广,储量大,但含硫气藏由于硫的存在,在生产开发过程中产生硫沉积,极大地破坏气井产能,因而含硫气井产能一直备受关注。一点法,修正等时试井法等常规试井方法和分析理论是否仍适用于含硫气井目前还缺乏理论依据。基于渗流力学理论,建立了含硫气井在非达西平面径向稳定渗流条件下的二项式产能方程,分析了硫沉积对气井产能的影响,并用现场的实测资料予以验证。结果证明常规试井方法对于含硫气井是适用的,这为含硫气井的试井分析方法提供了理论依据。 展开更多
关键词 二相式 产能方程 含硫气井 产能分析
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Prime Factorization in the Duality Computer 被引量:8
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作者 WANG Wan-Ying SHANG Bin +1 位作者 WANG Chuan LONG Gui-Lu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第3期471-473,共3页
We give algorithms to factorize large integers in the duality computer. We provide three duality algorithms for factorization based on a naive factorization method, the Shor algorithm in quantum computing, and the Fer... We give algorithms to factorize large integers in the duality computer. We provide three duality algorithms for factorization based on a naive factorization method, the Shor algorithm in quantum computing, and the Fermat's method in classical computing. All these algorithms may be polynomial in the input size. 展开更多
关键词 duality computer prime factorization Fermat's method
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320×240 Pixels CMOS Digital Image Sensor with Wide Dynamic Range
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作者 FANGJie WANGJing-guang HONGZhi-liang 《Semiconductor Photonics and Technology》 CAS 2004年第2期133-137,140,共6页
A 320×240 CMOS image sensor is demonstrated,which is implemented by a standard 0.6 μm 2P2M CMOS process.For reducing the chip area,each 2×2-pixel block shares a sample/hold circuit,analog-to-digital convert... A 320×240 CMOS image sensor is demonstrated,which is implemented by a standard 0.6 μm 2P2M CMOS process.For reducing the chip area,each 2×2-pixel block shares a sample/hold circuit,analog-to-digital converter and 1-b memory.The 2×2 pixel pitch has an area of 40 μm×40 μm and the fill factor is about 16%.While operating at a low frame rate,the sensor dissipates a very low power by power-management circuit making pixel-level comparators in an idle state.A digital correlated double sampling,which eliminates fixed pattern noise,improves SNR of the sensor, and multiple sampling operations make the sensor have a wide dynamic range. 展开更多
关键词 CMOS image sensor Digital image sensor PHOTODIODE Analog-to-digital converter Correlated double sampling Fixed pattern noise
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Entanglement of Generalized Two-Mode Binomial States and Teleportation
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作者 WANG Dong-Mei YU You-Hong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第4期631-636,共6页
The entanglement of the generalized two-mode binomial states in the phase damping channel is studied by making use of the relative entropy of the entanglement. It is shown that the factors of q and p play the crucial ... The entanglement of the generalized two-mode binomial states in the phase damping channel is studied by making use of the relative entropy of the entanglement. It is shown that the factors of q and p play the crucial roles in control the relative entropy of the entanglement. Furthermore, we propose a scheme of teleporting an unknown state via the generalized two-mode binomial states, and calculate the mean fidelity of the scheme. 展开更多
关键词 ENTANGLEMENT generalized two-mode binomial states TELEPORTATION
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Brun-Type Formalism for Decoherence in Two-Dimensional Quantum Walks
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作者 Clement Ampadu 《Communications in Theoretical Physics》 SCIE CAS CSCD 2012年第1期41-55,共15页
We study decoherence in the quantum walk on the xy-plane. We generalize the method of decoherent coin quantum walk, introduced by [T.A. Brun, et al., Phys. Rev. A 67 (2003) 032304], which could be applicable to all ... We study decoherence in the quantum walk on the xy-plane. We generalize the method of decoherent coin quantum walk, introduced by [T.A. Brun, et al., Phys. Rev. A 67 (2003) 032304], which could be applicable to all sorts of decoherence in two-dimensional quantum walks, irrespective of the unitary transformation governing the walk. As an application we study decoherence in the presence of broken line noise in which the quantum walk is governed by the two-dimensional ttadamard operator. 展开更多
关键词 coin-position decoherence quantum random walk coin decohcrence
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Novel similarity measures for face representation based on local binary pattern
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作者 祝世虎 封举富 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第2期223-226,共4页
The successful face recognition based on local binary pattern(LBP)relies on the effective extraction of LBP features and the inferring of similarity between the extracted features.In this paper,we focus on the latter ... The successful face recognition based on local binary pattern(LBP)relies on the effective extraction of LBP features and the inferring of similarity between the extracted features.In this paper,we focus on the latter and propose two novel similarity measures for the local matching methods and the holistic matching methods respectively.One is Earth Mover's Distance with Hamming and Lp ground distance(EMD-HammingLp),which is a cross-bin dissimilarity measure for LBP histograms.The other is IMage Hamming Distance(IMHD),which is a dissimilarity measure for the whole LBP images.Experiments on FERET database show that the proposed two similarity measures outperform the state-of-the-art Chi-square similarity measure for extraction of LBP features. 展开更多
关键词 similarity measurement local binary pattern Earth Mover's Distance IMage Euclidean Distance
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Electrical Capacitance Tomography Measurement of Flow Patterns and Film Thickness in a Thermosyphon 被引量:4
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作者 JingtaoLI QiCHEN +1 位作者 XiangyuanDONG ShiLIU 《Journal of Thermal Science》 SCIE EI CAS CSCD 2005年第1期81-86,共6页
An experimental study was performed to evaluate the suitability of using an electrical capacitance tomography (ECT) system to visualize the flow patterns, and to measure the film thickness of the annular flow in a two... An experimental study was performed to evaluate the suitability of using an electrical capacitance tomography (ECT) system to visualize the flow patterns, and to measure the film thickness of the annular flow in a two-phase closed thermosyphon (TPCT). The performance of the ECT system was examined over a range of flow conditions.The experimental data were compared with the visual observations and existing correlations. Results indicated that the ECT system, with the linear back projection (LBP) algorithm, could be used to give an on-line qualitative image of the flow patterns. The Landweber iteration algorithm with optimal step length was implemented off-line to reconstruct high-resolution images. Then, the images were analyzed to obtain the film thickness of the annular flow. The experimental data compared well with the Nusselt's equation in low vapor velocity range, but showed an increasing deficiency with the increase of vapor velocity. 展开更多
关键词 THERMOSYPHON electrical capacitance tomography film thickness flow pattern.
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Flow Pattern and Heat Transfer Behavior of Boiling Two-Phase Flow in Inclined Pipes
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作者 Liu Dezhang Ouyang Ning Nanjing Aeronautical Institute, 210016 Nanjing, China 《Journal of Thermal Science》 SCIE EI CAS CSCD 1992年第3期196-202,共7页
Movable Electrical Conducting Probe (MECP), a kind of simple and reliable measuring transducer, used for predicting full-flow-path flow pattern in a boiling vapor/liquid two-phase flow is introduced in this paper. Whe... Movable Electrical Conducting Probe (MECP), a kind of simple and reliable measuring transducer, used for predicting full-flow-path flow pattern in a boiling vapor/liquid two-phase flow is introduced in this paper. When the test pipe is set at different inclination angles, several kinds of flow patterns, such as bubble, slug, churn, intermittent, and annular flows, may be observed in accordance with the locations of MECP. By means of flow pattern analysis, flow field numerical calculations have been carried out, and heat transfer coefficient correlations along full-flow-path derived. The results show that heat transfer performance of boiling two-phase flow could be significantly augmented as expected in some flow pattern zones. The results of the investigation, measuring techniques and conclusions contained in this paper would be a useful reference in foundational research for prediction of flow pattern and heat transfer behavior in boiling two-phase flow, as well as for turbine vane liquid-cooling design. 展开更多
关键词 liquid/vapor two phase flow inclined pipes flow patterns heat transfer coefficient.
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Quantum entanglement of the binomial field interacting with a cascade three-level atom beyond the rotating wave approximation 被引量:6
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作者 PEN XueZao CONG HongLu +1 位作者 WANG XuWen XIA JianPing 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第9期1625-1630,共6页
In this paper, the quantum entanglement between a single mode binomial field and a cascade three-level atom is calculated mechanically without the rotating wave approximation. The numerical results indicate that the q... In this paper, the quantum entanglement between a single mode binomial field and a cascade three-level atom is calculated mechanically without the rotating wave approximation. The numerical results indicate that the quantum entanglement at the first few periods is reduced notably due to the fact that the atom is initially in the superposition state. With increasing field parameter 17, the period of the entanglement evolution becomes obvious and the quantum decoherence phenomenon emerges in a short time. 展开更多
关键词 binomial state field quantum entanglement field entropy
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A two-stage parametric subspace model for efficient contrast-preserving decolorization 被引量:2
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作者 Hong-yang LU Qie-gen LIU +1 位作者 Yu-hao WANG Xiao-hua DENG 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2017年第11期1874-1882,共9页
The RGB2GRAY conversion model is the most popular and classical tool for image decolorization. A recent study showed that adapting the three weighting parameters in this first-order linear model with a discrete search... The RGB2GRAY conversion model is the most popular and classical tool for image decolorization. A recent study showed that adapting the three weighting parameters in this first-order linear model with a discrete searching solver has a great potential in its c6nversion ability. In this paper, we present a two-step strategy to efficiently extend the parameter searching solver to a two-order multivariance polynomial model, as a sum of three subspaces. We show that the first subspace in the two-order model is the most important and the second one can be seen as a refinement. In the first stage of our model, the gradient correlation similarity (Gcs) measure is used on the first subspace to obtain an immediate grayed image. Then, Gcs is applied again to select the optimal result from the immettiate grayed image plus the second subspace-induced candidate images. Experimental results show the advantages of the proposed approach in terms of quantitative evaluation, qualitative evaluation, and algorithm complexity. 展开更多
关键词 Color-to-gray conversion Subspace modeling Two-order polynomial model Gradient correlation similarity Discrete searching
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Dually flat general spherically symmetric Finsler metrics
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作者 Xiaoming Wang Wangfu Liu Benling Li 《Science China Mathematics》 SCIE CSCD 2018年第4期769-782,共14页
Dually flat Finsler metrics arise from information geometry which has attracted some geometers and statisticians. In this paper, we study dually flat general spherically symmetric Finsler metrics which are defined by ... Dually flat Finsler metrics arise from information geometry which has attracted some geometers and statisticians. In this paper, we study dually flat general spherically symmetric Finsler metrics which are defined by a Euclidean metric and two related 1-forms. We give the equivalent conditions for those metrics to be locally dually flat. By solving the equivalent equations, a group of new locally dually flat Finsler metrics is constructed. 展开更多
关键词 Finsler metric general spherically symmetric dually flat Euclidean metric
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