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Stochastically Perturbed Parameterizations for the Process-Level Representation of Model Uncertainties in the Cma Global Ensemble Prediction System

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Journal of Meteorological Research 2022年第5期36卷 733-749页

作者： fei peng Xiaoli LI Jing CHEN Cma Earth System Modeling and Prediction Centre China Meteorological Administration(CMA)Beijing 100081 State Key Laboratory of Severe Weather China Meteorological AdministrationBeijing 100081 National Meteorological Centre China Meteorological AdministrationBeijing 100081

To represent model uncertainties at the physical process level in the China Meteorological Administration global ensemble prediction system(Cma-GEPS),a stochastically perturbed parameterization(SPP)scheme is developed by perturbing 16 parameters or variables selected from three physical parameterization schemes for the planetary boundary layer,cumulus convection,and cloud *** chosen quantity is perturbed independently with temporally and spatially correlated perturbations sampled from log-normal *** of the SPP scheme on Cma-GEPS are investigated comprehensively by using the stochastically perturbed parametrization tendencies(SPPT)scheme as a *** the absence of initial-condition perturbations,perturbation structures introduced by the two schemes are investigated by analyzing the ensemble spread of three forecast variables’physical tendencies and perturbation energy in ensembles generated by the separate use of SPP and *** is revealed that both schemes yield different perturbation structures and can simulate different sources of model *** initialcondition perturbations are activated,the influences of the two schemes on the performance of Cma-GEPS are assessed by calculating verification scores for both upper-air and surface *** improvements in ensemble reliability and probabilistic skill introduced by SPP and SPPT are mainly located in the ***,the vast majority of the reliability improvements(including increases in ensemble spread and reductions in outliers)are statistically significant,and a smaller proportion of the improvements in probabilistic skill(i.e.,decreases in continuously ranked probability score)reach statistical *** with SPPT,SPP generally has more beneficial impacts on200-hPa and 2-m temperature,along with 925-hPa and 2-m specific humidity,during the whole 15-day forecast *** other examined variables,such as 850-hPa zonal wind,850-hPa temperature,and

关键词： model uncertainty global ensemble forecast stochastic physics parameter perturbation perturbation structure

Efficient parallel adaptive array beamforming algorithm

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Journal of Systems Engineering and Electronics 2009年第6期20卷 1221-1226页

作者： Huang fei Sheng Weixing ma Xiaofeng Dept. of Communication Engineering Nanjing Univ. of Science and Technology Nanjing 210094 P. R. China

For a large-scale adaptive array, the heavy computational load and the high-rate data transmission are two challenges in the implementation of an adaptive digital beamforming system. An efficient parallel digital beamforming （DBF） algorithm based on the least mean square algorithm （PLMS） is proposed. An appropriate method is found to partition the least mean square （LMS） algorithm into a number of operational modules, which can be easily executed in a distributed-parallel-processing fashion. As a result, the proposed PLMS algorithm provides an effective solution that can alleviate the bottleneck of high-rate data transmission and reduce the computational cost. PLMS requires less computational load than that of the conventional parallel algorithms based on the recursive least square （RLS） algorithm, as well as it is easier to be implemented to do real time adaptive array processing. Moreover, low sidelobe of the beam pattern is obtained by constraining the static steering vector with Tschebyscheff coefficients. Finally, a scheme of the PLMS algorithm using distributed-parallel-processing system is also proposed. The simulation results demonstrate that the PLMS algorithm has the same interference cancellation performance as that of the conventional LMS algorithm. Moreover, the PLMS algorithm can obtain the same good beamforming performance, regardless how the algorithm is partitioned. It is expected that the proposed algorithm will be used in a large-scale adaptive array system to deal with real time adaptive digital beamforming processing.

关键词： adaptive digital beamforming parallel algorithm least mean square generalized sidelobe canceller.

Rate-distortion weighted SPIHT algorithm for interferometer data processing

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Journal of Systems Engineering and Electronics 2011年第4期22卷 547-556页

作者： Jing ma Jindong fei Dong Chen Science and Technology on Space Systems Simulation Laboratory Beijing Simulation Center Beijing 100854 E R. China Institute of Telecommunication Satellite China Academy of Space Technology Beijing 100094 P. R. China

As one of the next generation imaging spectrometers, the interferential spectrometer （iS） possesses the advantages of high throughput, multi-channel and great resolution. The data of IS are produced in the spatial domain, but optical applications are in the Fourier domain. Traditional compression methods can only protect the visual quality of interferometer data in the spatial do- main but ignore the distortion in the Fourier domain. The relation between the distortion in the Fourier domain and the compression in the spatial domain is analyzed. By mathematical proof and val- idation with experiments, the relation between spatial and Fourier domains is discovered, and the significance in the Fourier domain is more important as optical path difference （OPD） increasing in the spatial domain. Based on this relation, a novel coding scheme is proposed, which can compress data in the spatial domain while reducing the distortion in the Fourier domain. In this scheme, the bit stream of the set partitioning in hierarchical trees （SPIHT） is truncated by adaptively lifting rate-distortion slopes according to the priorities of OPD based on rate-distortion optimization theory. Experimental results show that the proposed method can provide better protection of spectrum curves in the Fourier domain while maintaining a comparable visual quality in the spatial domain.

关键词： interferential spectrometer (IS) multi-spectrum compression set partitioning in hierarchical trees (SPIHT).

Privacy-preserving authentication scheme based on zero trust architecture

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Digital Communications and Networks 2024年第5期10卷 1211-1220页

作者： fei Tang Chunliang ma Kefei Cheng College of Computer Science and Technology Chongqing University of Posts and Telecommunications School of Cyber Security and Information Law Chongqing University of Posts and Telecommunications

Zero trust architecture is an end-to-end approach for server resources and data security which contains identity authentication,access control,dynamic evaluation,and so *** work focuses on authentication technology in the zero trust *** this paper,a Traceable Universal Designated Verifier Signature(TUDVS) is used to construct a privacy-preserving authentication scheme for zero trust ***,when a client requests access to server resources,we want to protect the client's access privacy which means that the server administrator cannot disclose the client's access behavior to any third *** addition,the security of the proposed scheme is proved and its efficiency is ***,TUDVS is applied to the single packet authorization scenario of the zero trust architecture to prove the practicability of the proposed scheme.

关键词： Zero trust architecture Privacy-preserving Authentication Anonymity revocation

Three dimensional phase-field simulation for non-isothermal binary alloy solidification: Comparison with LKT theory

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China Foundry 2023年第6期20卷 545-552页

作者： Jun Wu Ting-yi Liu Gui-chao Hu Rong ma Xiao-peng Zhang Yu-fei Li Chao Luo Institute of materials China Academy of Engineering PhysicsJiangyou 621907SichuanChina

Using the advanced algorithm combining parallel computing,adaptive mesh re-griding and multigrid methods,quantitative 3D phase-field simulations of non-isothermal solidification of binary alloy were carried *** 3D phase-field simulation results were compared with the analytical LKT(Lipton,Kurz and Trivedi)*** comparison,the simulation and analytical results for 2D cases were also *** 3D phase-field simulation results support the transport portion of the LKT ***,the tip radius and tip velocity predicted by the simulations are not in good agreement with the LKT theory over the whole range of *** stability parameter calculated from phase-field simulations varies significantly with the Peclet number,indicating that the stability criterion,which assumes that the stability parameter is constant,is invalid.

关键词： 3D phase-field non-isothermal solidification free dendritic growth

Minimal two-spheres with constant curvature in the quaternionic projective space

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Science China mathematics 2020年第5期63卷 993-1006页

作者： Jie fei Chiakuei peng Xiaowei Xu Department of mathematical Sciences Xi’an Jiaotong-Liverpool UniversitySuzhou 215123China School of mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China Department of mathematics University of Science and Technology of ChinaHefei 230026China Wu Wen-Tsun Key Laboratory of mathematics University of Science and Technology of ChinaChinese Academy of SciencesHefei 230026China

In this paper we completely classify the homogeneous two-spheres,especially,the minimal homogeneous ones in the quaternionic projective space *** to our classification,more minimal constant curved two-spheres in HPnare obtained than what Ohnita conjectured in the paper"Homogeneous harmonic maps into complex projective *** J math,1990,13:87–116".

关键词： minimal two-sphere Gauss curvature quaternionic projective space

Comparative analysis of mitochondrial fragments transferred to the nucleus in vertebrate

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Journal of Genetics and Genomics 2008年第8期35卷 485-490页

作者： Hongying Qu fei ma Qingwei Li Institute of marine Genomics ＆ Proteomics Liaoning Normal University Dalian 116029 China

Mitochondrial DNA sequences transferred to the nucleus give rise to the so-called nuclear mitochondrial DNA （numt）. In the GenBank database, 244 numts have been found in six orders of birds （Anseriformes, Columbiformes, Falconiformes, Charadriiformes, Galliformes and Passeriformes）. Sequences alignment （NCBI-BLASTN） was carded out with mitochondrial and corresponding nuclear genome sequences in nine vertebrate species. The sequences with high homology were considered as numts. The number of numts ranged from 15 in chicken to 159 in chimpanzee. The sequences of numts in macaque, chimpanzee, and human spanned 100% of the entire mammalian mitochondrial genome. The reconstructed frequency of the mitochondrial gene transferred to the nucleus demonstrated that the rRNA genes had high frequencies than other mitochondrial genes. Using the Repeatmasker program, the transposable elements were detected in the flanking regions of each numt. The results showed that less than 5% of the flanking sequences were made up of repetitive elements in chicken. The GC content of 5＇- and 3＇-flanking regions of numts in nine species was less than 44%. The analysis of the flanking sequences provided a valuable understanding for future study on mechanism of mitochondrial gene transfer to the nucleus and the site of numt integration.

关键词： mitochondrial DNA numts nuclear insertion flanking sequence vertebrate

Optimal production lot size with process deterioration under an extended inspection policy

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Journal of Systems Engineering and Electronics 2009年第4期20卷 768-776页

作者： Hu fei Xu Genqi ma Lixia Dept. of mathematics Tianjin Univ. Tianjin 300072 P. R. China

A mathematical model to determine the optimal production lot size for a deteriorating production system under an extended product inspection policy is developed. The last-K product inspection policy is considered so that the nonconforming items can be reduced, under which the last K products in a production lot are inspected and the nonconforming items from those inspected are reworked. Consider that the products produced towards the end of a production lot are more likely to be nonconforming, is proposed an extended product inspection policy for a deteriorating production system. That is, in a production lot, product inspections are performed among the middle K1 items and after inspections, all of the last K2 products are directly reworked without inspections. Our objective here is the joint optimization of the production lot size and the corresponding extended inspection policy such that the expected total cost per unit time is minimized. Since there is no closed form expression for our optimal policy, the existence for the optimal production inspection policy and an upper bound for the optimal lot size are obtained. Furthermore, an efficient solution procedure is provided to search for the optimal policy. Finally, numerical examples are given to illustrate the proposed model and indicate that the expected total cost per unit time of our product inspection model is less than that of the last-K inspection policy.

关键词： production lot size product inspection policy deteriorating production system economic manufacturing quantity.

Electrodeposited transparent PEDOT for inverted perovskite solar cells:improved charge transport and catalytic performances

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Rare Metals 2021年第9期40卷 2402-2414页

作者： Cong-Tan Zhu Ying Yang fei-Yu Lin Yuan Luo Shu-peng ma Liu Zhu Xue-Yi Guo School of Metallurgy and Environment Central South UniversityChangsha 410083China First Rare materials Co. LtdQingyuan 511517China

The acidic, corrosive effect of sodium polystyrene sulfonate(PSS) in poly 3,4-ethylenedioxythiophene:sodium polystyrene sulfonate(PEDOT:PSS) limits the stability of inverted perovskite solar cells(PSCs) based on the ITO/PEDOT:PSS/perovskite/PCBM/BCP/Ag structure. In this work, a poly 3,4-ethylenedioxythiophene(PEDOT) hole transport layer(HTL) with high hole mobility and good catalytic performance was prepared by electrochemical cyclic voltammetry(CV) method for inverted PSCs. By controlling the CV cycles(from 1 to 5 cycles) and EDOT monomer solution concentration(from0.5 to 2.0 mmol·L^(-1)) of electrochemical deposition, the thickness, morphology, optical and electrochemical properties of PEDOT could be accurately adjusted. The optimal photovoltaic performance with current density(J_(sc)) of 22.19 ma·cm^(-2), open circuit voltage(V_(oc)) of 0.94 V, fill factor(FF) of 0.65 and photoelectric conversion efficiency of 13.56% was obtained when deposition of PEDOT with 1 CV cycle and EDOT concentration of 0.5 mmol·L^(-1). At this point, the perovskite showed good crystallization,optimal optical, charge transport and recombination performance, resulting in better V_(oc)and photoelectric conversion efficiency(PCE) compared to the devices with higher CV cycle numbers and 3,4-ethylenedioxythiophene(EDOT) concentration. For comparison with spin-coated PEDOT:PSS, the device with electrodeposited PEDOT showed improved J_(sc)and comparable V_(oc), which may result from its better charge transport and catalytic *** device with spin-coated PEDOT:PSS showed photoelectric conversion efficiency of 12.25%, which was lower than that based on electrodeposited PEDOT(13.56%) with1 CV cycles and 0.5 mmol·L^(-1) EDOT concentration. And the device with electrodeposited PEDOT as HTLs showed more excellent air stability. In ambient air((32 ± 5) ℃ and RH: 70% ± 20%), it still maintained more than 80%of the initial photoelectric conversion efficiency after1000 h. In comparison, the photoe

关键词： Electrochemically cyclic voltammetry Inverted perovskite solar cells Electrodeposited PEDOT Hole mobility Tafel analysis