- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2018 OCEANS - MTS/IEEE Kobe Techno-Ocean (OTO) - Kobe, Japan (2018.5.28-2018.5.31)] 2018 OCEANS - MTS/IEEE Kobe Techno-Oceans (OTO) - Parameter Estimation for Rayleigh-Pearson Mixture Model Based on Expectation-Maximization Algorithm
摘要： In this paper I propose a mixture distribution model with Rayleigh and Pearson distributions in order to represent the statistics of the reverberation. In addition the paper studies a parameter estimation method for the mixture distribution. As a preliminary step the parameter estimation of Pearson distribution is studied. Then the method of the parameter estimation is derived in the Rayleigh-Pearson mixture model based on the expectation-maximization (EM) technique. Simulation results have demonstrated that the parameter estimation method provides adequate performance.
关键词： Pearson distribution,parameter estimation,EM algorithm,mixture distribution
更新于2025-09-23 15:22:29
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Preparation of ortho-symmetric double (OSD) Z-scheme SnO2\CdSe/Bi2O3 sonocatalyst by ultrasonic-assisted isoelectric point method for effective degradation of organic pollutants
摘要： In this paper, the maximum domain of attraction of the three-parameter conditional Exponential-Weibull distribution is studied. The conditional Exponential-Weibul distribution is confirmed and proven to belong to the maximum domain of attraction of the Gumbel distribution, and the expressions of the corresponding normalizing constants are derived. Numerical simulations are conducted to investigate the performance of the proposed normalizing constants.
关键词： Maximum domain of attraction,Exponential-Weibull distribution,Normalizing constants,Extreme value distribution
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Detection of Uniformly Accelerated Spinning Target Based on OAM Beams
摘要： In recent years, it has been validated that electromagnetic (EM) wave carrying orbital angular momentum (OAM) can be exploited to detect the angular velocity of spinning targets with uniform velocity. In this paper, the detection method of uniformly accelerated spinning target using OAM beams is studied. The time-frequency analysis approaches, including the Wigner-Ville distribution (WVD) and the fractional order Fourier transform (FRFT), are used to analyze the rotational Doppler frequency shift caused by spinning targets. Simulation results indicate that the resolution of acceleration is dependent on the spectrum width of time-frequency diagrams of the echo signal.
关键词： OAM beams,rotational Doppler frequency shift,uniformly accelerated spinning target,Wigner-Ville distribution,fractional order Fourier transform
更新于2025-09-23 15:22:29
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[IEEE 2018 25th International Conference on Mechatronics and Machine Vision in Practice (M2VIP) - Stuttgart, Germany (2018.11.20-2018.11.22)] 2018 25th International Conference on Mechatronics and Machine Vision in Practice (M2VIP) - 3D Point Cloud Coarse Registration based on Convex Hull Refined by ICP and NDT
摘要： Non-rigid registration is a crucial step for many applications such as motion tracking, model retrieval, and object recognition. The accuracy of these applications is highly dependent on the initial position used in registration step. In this paper we propose a novel Convex Hull Aided Coarse Registration refined by two algorithms applied on projected points.Firstly,the proposed approach uses a statistical method to find the best plane that represents each point cloud. Secondly, all the points of each cloud are projected onto the corresponding planes. Then, two convex hulls are extracted from the two projected point sets and then matched optimally. Next, the non-rigid transformation from the reference to the model is robustly estimated through minimizing the distance between the matched point's pairs of the two convex hulls.Finally, this transformation estimation is refined by two methods. The first one is the refinement of coarse registration by Iterative Closest Point (ICP). The second one consists of the refinement of coarse registration by the Normal Distribution Transform (NDT). An experimental study ,carried out on several clouds, shows that the refinement of coarse registration with ICP gives, in the most cases, a better result than refinement with NDT.
关键词： Iterative Closest Point (ICP),Convex Hull,Normal Distribution Transform (NDT),Non rigid registration,3D point cloud,Principal Component Analysis (PCA)
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE Power & Energy Society General Meeting (PESGM) - Portland, OR, USA (2018.8.5-2018.8.10)] 2018 IEEE Power & Energy Society General Meeting (PESGM) - Increasing Feeder PV Hosting Capacity by Regulating Secondary Circuit Voltages
摘要： Voltage rise is one of the major concerns that limits the photovoltaic (PV) hosting capacity or the maximum amount of PV generation that a distribution circuit can accommodate. This paper examines the effectiveness of low-voltage distribution static compensators (LV-DSTATCOMs) in increasing the PV hosting capacity of distribution circuits by mitigating voltage rise. Stochastic analysis framework is used to determine the PV hosting capacity while an iterative placement technique is used to identify effective device locations. To provide insights on the optimal device size, number, and control settings, sensitivity analysis is carried out. The results show that, with appropriate size and control settings, installation of few LV-DSTATCOMs in a distribution circuit can significantly increase its PV hosting capacity. For the circuit under consideration, a set of 23 devices has increased the PV hosting capacity from 15% to 100% of the median day time peak load.
关键词： Distribution circuit,Photovoltaics,FACTS device,Overvoltage,DSTATCOM
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Radar (RADAR) - Brisbane, Australia (2018.8.27-2018.8.31)] 2018 International Conference on Radar (RADAR) - Space-Range-Doppler Focus Processing: A Novel Solution for Moving Target Integration and Estimation Using FDA-MIMO Radar
摘要： Frequency diverse array (FDA) is an emerging array technique that employs a small frequency increment across its array elements to produce a range-angle-dependent beampattern, which provides promising applications for joint angle-range estimation of targets. However, the FDA has several problems for signal processing, such as angle and range coupling and Doppler integration, and few papers deal with FDA for moving target. In this paper, we combine the FDA and MIMO technique and propose the concept of space (angle)-range-Doppler (SRD) focus processing, which is a novel solution for moving target integration and estimation. It utilizes the property of FDA and high-resolution Doppler processing of MIMO. Based on the data model of FDA-MIMO radar, we provide a practical method for SRD processing via A&D joint estimation and sparse time-frequency distribution (STFD). Both theoretical and numerical simulation results verify that proposed method has better ability for joint range-angle-Doppler processing, which can be used for low-observable moving target detection and estimation under complex environment.
关键词： Moving target integration,Space-Range-Doppler (SRD) focus processing,Frequency diverse array (FDA) radar,Sparse time-frequency distribution (STFD)
更新于2025-09-23 15:22:29
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Nitrogen mapping from ADF imaging analysis in quaternary dilute nitride superlattices
摘要： A method for the determination of N distribution in dilute nitride GaAsSbN superlattices (SLs) by using different STEM imaging settings is proposed. The method combines the simultaneous acquisition under Low Angle (LA-) and High Angle (HA-) Annular Dark Field (ADF) conditions by exploiting two different dedicated angle intervals. On one hand, HAADF technique gives information that principally depends on the atomic number (Sb sensitive) and on the other hand, N atoms produce high static atomic displacements affecting the image intensity especially under LAADF conditions. However, the simultaneous presence of Sb and N supposes an important handicap to differentiate both elements. N distribution maps could be obtained from suitable normalization and the separation of the intensity ratios in regions with/without Sb. Semi-quantitative maps are also available by combination of the results from high-resolution X-ray diffraction and energy dispersive X-Ray spectroscopy techniques. Type-I (GaAsSbN/GaAs) and type-II (GaAsSb/GaAsN) SL structures are evaluated using the proposed methodology. Differences in the N distribution between both samples such as inhomogeneities and cluster formation are discussed. Specifically, we have found a greater number of N-rich regions in type-I structure as compared to their type-II counterparts, which could have an influence on the optical response of each design.
关键词： STEM,Dilute nitride,Compositional distribution,Superlattice structures
更新于2025-09-23 15:22:29
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Fabrication and electromagnetic wave absorption property of quartz ceramics with a gradient distribution of BaTiO3
摘要： Quartz ceramics with a uniform/gradient distribution of BaTiO3 (U/G–SO–BTO) are fabricated by cold pressing a powder blend with BTO followed by sintering and using a combined technique of spreading the powder blends with gradually increased BTO layer–by–layer and sintering. The electromagnetic wave absorption properties of these two ceramics are studied in detail. For U–SO–BTO samples, the primary electromagnetic re?ection is strong due to the aggravated impedance mismatch at their surfaces. The electromagnetic wave re?ectivity of U–SO–BTO could only reach ?7.0 dB when the sample thickness is 6 mm and the BTO content is 8.0 wt%, and it decreases slightly to ?8.1 dB when the sample thickness is increased to 10.0 mm and the BTO content is decreased to 5.0 wt% simultaneously. For G–SO–BTO samples, electromagnetic waves could enter with little re?ection due to the weak surface impedance mismatch, and the electromagnetic waves entering these samples could propagate forward while being absorbed gradually with little re?ection because of the weak impedance mismatch at the interfaces. The G–SO–BTO samples are promising excellent electromagnetic absorbing materials because their electromagnetic wave re?ectivity could reach a level lower than ?12.0 dB and could decrease further from –12.2 to ?13.1 dB as the layer thickness increases from 1.0 to 2.0 mm.
关键词： Impedance mismatch,Electromagnetic wave absorption,Quartz ceramics,Electromagnetic re?ection,Gradient distribution,BaTiO3
更新于2025-09-23 15:22:29
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Dynamic Tariff-Subsidy Method for PV and V2G Congestion Management in Distribution Networks
摘要： This paper proposes a dynamic tariff-subsidy (DTS) method for congestion management in distribution networks with high penetration of photovoltaics (PV), heat pumps (HPs) and electric vehicles (EVs) with vehicle-to-grid (V2G) function. The DTS method is an extension of the dynamic tariff method proposed in the previous study. With the DTS, the regulation prices can be positive (tariff) or negative (subsidy). The study shows that the negative regulation price is necessary and very effective to solve congestion due to feed-in power flows, such as PVs and EVs in the V2G mode. In the study, dual decomposition of a convex quadratic model is proposed in addition to a conventional method for the DTS calculation. The case studies on the Roy Billinton Test System (RBTS) demonstrate the efficacy of the DTS method for congestion management in distribution networks.
关键词： distribution system operator (DSO),electric vehicle (EV),photovoltaics (PV),dynamic tariff-subsidy,Congestion management,heat pump (HP)
更新于2025-09-23 15:22:29
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Memory-assisted quantum key distribution resilient against multiple-excitation effects
摘要： Memory-assisted measurement-device-independent quantum key distribution (MA-MDI-QKD) has recently been proposed as a technique to improve the rate-versus-distance behavior of QKD systems by using existing, or nearly-achievable, quantum technologies. The promise is that MA-MDI-QKD would require less demanding quantum memories than the ones needed for probabilistic quantum repeaters. Nevertheless, early investigations suggest that, in order to beat the conventional memory-less QKD schemes, the quantum memories used in the MA-MDI-QKD protocols must have high bandwidth-storage products and short interaction times. Among different types of quantum memories, ensemble-based memories offer some of the required specifications, but they typically suffer from multiple excitation effects. To avoid the latter issue, in this paper, we propose two new variants of MA-MDI-QKD both relying on single-photon sources for entangling purposes. One is based on known techniques for entanglement distribution in quantum repeaters. This scheme turns out to offer no advantage even if one uses ideal single-photon sources. By finding the root cause of the problem, we then propose another setup, which can outperform single memory-less setups even if we allow for some imperfections in our single-photon sources. For such a scheme, we compare the key rate for different types of ensemble-based memories and show that certain classes of atomic ensembles can improve the rate-versus-distance behavior.
关键词： quantum cryptography,quantum networks,quantum key distribution (QKD),quantum memory,single-photon source,quantum communications
更新于2025-09-23 15:22:29