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北京“23·7”极端强降雨特征和成因分析

气象 2024年第5期50卷 616-629页

作者：荆浩亢妍妍吴宏议雷蕾郭锐赵玮于波北京市气象台北京100097

利用北京地区加密气象站、补盲的北京市规划和自然资源委员会雨量站、双偏振雷达、风廓线雷达、GPS水汽等观测数据和ERA5再分析数据,对北京“23·7”极端强降雨阶段性特征和成因进行了分析。结果表明:“23·7”极端强降雨累计降水量(331... 详细信息

利用北京地区加密气象站、补盲的北京市规划和自然资源委员会雨量站、双偏振雷达、风廓线雷达、GPS水汽等观测数据和ERA5再分析数据,对北京“23·7”极端强降雨阶段性特征和成因进行了分析。结果表明:“23·7”极端强降雨累计降水量(331 mm)和单点最大降水量(1025 mm)均打破历史纪录,最大雨强(126.6 mm·h^(-1))排名历史第二位,具有显著的极端性。强降雨可分为5个阶段,其中第Ⅱ和第Ⅳ阶段降水量分别占过程累计降水量的37.1%和39.7%,第Ⅳ阶段雨强更大,对应急流更强,高温、高湿特征也更明显。地形对降雨的增幅作用显著,降水量在海拔100~300 m山区迅速增加,极大值出现在海拔约400 m的山区,第Ⅱ(第Ⅳ)阶段山区平均降水量和小时雨强分别是平原的2.1(3.0)倍和2.0(2.7)倍;第Ⅱ阶段主要为地形对急流的直接抬升,第Ⅳ阶段为地形绕流辐合和直接抬升共同作用。7月31日上午(第Ⅳ阶段)边界层急流出口区与低空急流入口区耦合导致低层上升运动增强,促使西部山前β中尺度对流系统由块状发展成线状并有γ中尺度涡旋产生,该β中尺度对流系统北上时形成短暂的列车效应,引发了西部山区8个站次100 mm·h^(-1)以上的极端短时强降水。

关键词： “23·7”极端强降雨地形作用低空急流中尺度对流系统 γ中尺度涡旋

DeepPOSE:Detecting GPS spoofing attack via deep recurrent neural network

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Digital Communications and Networks 2022年第5期8卷 791-803页

作者： Peng Jiang hongyi wu Chunsheng Xin ECE Dept.and School of Cybersecurity Old Dominion UniversityNorfolkVA23529USA

The Global Positioning System(GPS)has become a foundation for most location-based services and navigation systems,such as autonomous vehicles,drones,ships,and wearable ***,it is a challenge to verify if the reported geographic locations are valid due to various GPS spoofing *** tools,such as Fake GPS,Lockito,and software-defined radio,enable ordinary users to hijack and report fake GPS coordinates and cheat the monitoring server without being ***,it is also a challenge to get accurate sensor readings on mobile devices because of the high noise level introduced by commercial motion *** this end,we propose DeepPOSE,a deep learning model,to address the noise introduced in sensor readings and detect GPS spoofing attacks on mobile *** design uses a convolutional and recurrent neural network to reduce the noise,to recover a vehicle's real-time trajectory from multiple sensor *** further propose a novel scheme to map the constructed trajectory from sensor readings onto the Google map,to smartly eliminate the accumulation of errors on the trajectory *** reconstructed trajectory from sensors is then used to detect the GPS spoofing *** with the existing method,the proposed approach demonstrates a significantly higher degree of accuracy for detecting GPS spoofing attacks.

关键词： GPS spoofing attack Position estimation Recurrent neural network

A channel state information based virtual MAC spoofing detector

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High-Confidence Computing 2022年第3期2卷 1-6页

作者： Peng Jiang hongyi wu Chunsheng Xin Department of ECE Old Dominion UniversityNorfolkVAUSA School of Cybersecurity Old Dominion UniversityNorfolkVAUSA

Physical layer security has attracted lots of attention with the expansion of wireless devices to the edge networks in recent *** to limited authentication mechanisms,MAC spoofing attack,also known as the identity attack,threatens wireless *** this paper,we study a new type of MAC spoofing attack,the virtual MAC spoofing attack,in a tight environment with strong spatial similarities,which can create multiple counterfeits entities powered by the virtualization technologies to interrupt regular *** develop a system to effectively detect such virtual MAC spoofing attacks via the deep learning method as a countermeasure.A deep convolutional neural network is constructed to analyze signal level information extracted from Channel State Information(CSI)between the communication peers to provide additional authentication protection at the physical layer.A significant merit of the proposed detection system is that this system can distinguish two different devices even at the same location,which was not well addressed by the existing *** extensive experimental results demonstrate the effectiveness of the system with an average detection accuracy of 95%,even when devices are co-located.

关键词： Virtual Mac spoofing Channel state information Deep learning

基于热图像的GWOA-BiLSTM机床主轴热误差预测

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制造技术与机床 2024年第8期 175-181页

作者：张婉君陈瑶韩越吴弘毅王建臣邓小雷衢州学院浙江省空气动力装备技术重点实验室浙江衢州324000 浙江工业大学机械工程学院浙江杭州310023

热误差是影响高精密数控机床加工精度的重要因素。为了提高机床加工精度和性能,减少机床运行中产生的热误差,文章提出一种基于热图像的灰狼优化算法(grey wolf optimization algorithm,GWOA)和双向长短期记忆神经网络(bidirectional lon... 详细信息

热误差是影响高精密数控机床加工精度的重要因素。为了提高机床加工精度和性能,减少机床运行中产生的热误差,文章提出一种基于热图像的灰狼优化算法(grey wolf optimization algorithm,GWOA)和双向长短期记忆神经网络(bidirectional long short-term memory,BiLSTM)混合的热误差预测模型。首先,采用热成像仪获取机床主轴区域的温度场信息;其次,利用DBSCAN聚类(density-based spatial clustering of applications with noise)算法和相关系数法筛选出温度敏感点;然后,通过模拟灰狼群体捕食行为,在参数空间中进行搜索以找到BiLSTM所需的最优参数;最后,使用获得的机床温度敏感点和热位移数据进行热误差预测,并在试验机床上进行验证。实验结果表明,使用GWOA优化BiLSTM神经网络的预测模型相比BiLSTM神经网络预测模型的均方根误差(root mean square error,RMSE)和平均绝对误差(mean absolute error,MAE)分别减小了约0.5180、0.3823μm,决定系数R^(2)提升了0.0578。与BiLSTM神经网络模型相比,利用GWOA优化后的模型具有更加优良的预测性能。

关键词：热图像灰狼优化算法 BiLSTM神经网络热误差建模机床测点优化

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四质子非束缚核^(18)Mg的实验研究

原子核物理评论 2024年第1期41卷 163-171页

作者：金瑜倪磊华辉李智焕牛晨阳吴鸿毅北京大学物理学院和核物理与核技术国家重点实验室北京100871 中国工程物理研究院材料研究所四川绵阳621907

对滴线外原子核自发核子发射现象的实验研究,有助于人们探寻滴线外的新核素,揭示非束缚原子核的奇特结构和衰变特性,进而探索原子核稳定性的极限、理解同位旋极端不对称条件下核子间的相互作用。文章将介绍我们对质子滴线外的新镁同位素... 详细信息

对滴线外原子核自发核子发射现象的实验研究,有助于人们探寻滴线外的新核素,揭示非束缚原子核的奇特结构和衰变特性,进而探索原子核稳定性的极限、理解同位旋极端不对称条件下核子间的相互作用。文章将介绍我们对质子滴线外的新镁同位素^(18)Mg的四质子衰变现象的实验研究。首先介绍实验使用的放射性束流线和探测器设置,给出了束流粒子与衰变产物的粒子鉴别结果。然后重点介绍了闪烁光纤探测阵列及其数据分析方法。结合该阵列在本次实验中的探测效率和位置分辨表现,模拟结果证明了该阵列对于提高不变质量谱分辨的必要性。最后利用不变质量法,由^(14)O+4p五体符合测量事件重建得到了^(18)Mg的衰变能谱。Gamow壳模型理论计算可以较好地描述实验结果,表明连续谱耦合效应对于滴线外原子核的结构存在显著影响。实验测得的^(18)Mg的2_(1)^(+)态激发能比传统幻数核^(20)Mg更高,表明在极端丰质子的Mg同位素中可能出现了N=8的壳减弱或某些奇特的核结构效应。

关键词：滴线新核素四质子衰变 ^(18)Mg 不变质量法 N=8壳

DUAL FUNCTIONALS OF SAID-BZIER TYPE GENERALIZED BALL BASES OVER TRIANGLE DOMAIN AND THEIR APPLICATION

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Applied Mathematics(A Journal of Chinese Universities) 2006年第1期21卷 96-106页

作者： wu hongyi Dept. of Math Hefei Univ. of Technology Hefei 230009 China.

A family of Said-Bézier type generalized Ball （SBGB） bases and surfaces with a parameter H over triangular domain is introduced,which unifies Bézier surface and Said-Ball surface and includes several intermediate surfaces. To convert different bases and surfaces,the dual functionals of bases are presented. As an application of dual functionals,the subdivision formulas for surfaces are established.

关键词： Bézier basis Said-Bézier type generalized Ball (SBGB) basis triangular domain dual functional ,subdivision formula.

Design and Analysis of Prioritized Medium Access Control Protocol for Backbone Routers in Wireless Mesh Networks

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Tsinghua Science and Technology 2012年第5期17卷 537-552页

作者： Lei Pan hongyi wu Qualcomm Inc. 1700 Technology Dr.San JoseCA 95110USA The Center for Advanced Computer Studies University of Louisiana at LafayetteLafayetteLA 70504USA

A Prioritized Medium Access Control （P-MAC） protocol is proposed for wireless routers of mesh networks with quality-of-service provisioning. The simple yet effective design of P-MAC offers strict service differentiation for prioritized packets. A Markov model is developed to yield important performance matrices including the packet blocking probability due to queue overflow and the packet reneging probability due to delay bound. It is further proved that the service time of P-MAC approximates exponential distribution, and can be effectively estimated. The analytic models with preemptive and non-preemptive schemes, validated via simulations, show that P-MAC can effectively support traffic differentiation and achieve very low packet dropping （both reneging and blocking） probabilities when the traffic load is below the channel capacity. When the network is overloaded, P-MAC can still maintain extremely stable and high channel throughput. Moreover, it is demonstrated that P-MAC performs superior in multihop networks, further proving the advantages of the proposed protocol.

关键词： Markov chain reneging medium access control binary countdown packet priorization network throughput Quality-of-Service (QoS) wireless mesh networks wireless routers

非编码RNA介导去势抵抗型前列腺癌对恩杂卢胺耐药的机制

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泌尿外科杂志(电子版) 2024年第2期16卷 77-81页

作者：尹皓立徐石义李俊吴弘毅刘天飞王启林云南省肿瘤医院泌尿外科一病区

前列腺癌患者常在基础雄激素剥夺治疗后出现激素治疗抵抗,从而发展为去势抵抗型前列腺癌(castrationresistant prostate cancer,CRPC)。随着大量临床试验结果的公布,展现了恩杂卢胺作为二代抗雄药物对CRPC良好的治疗效果,显著延长患者... 详细信息

前列腺癌患者常在基础雄激素剥夺治疗后出现激素治疗抵抗,从而发展为去势抵抗型前列腺癌(castrationresistant prostate cancer,CRPC)。随着大量临床试验结果的公布,展现了恩杂卢胺作为二代抗雄药物对CRPC良好的治疗效果,显著延长患者总生存期。然而,30%的患者在接受恩杂卢胺治疗后出现药物耐药,给晚期前列腺癌患者治疗带来巨大挑战。非编码RNA (non-coding RNA,ncRNA)作为近年来分子生物学领域的研究热点,其广泛的生物学功能已介入众多疾病治疗进程中,大量研究揭示其在肿瘤发生发展、药物耐药中的关键作用。因此,阐明ncRNA与恩杂卢胺耐药性的相互关系可为深入了解恩杂卢胺耐药的发生和发展提供新思路,为逆转晚期前列腺癌治疗困境提供新靶点。本文着重阐述微小核糖核酸(microRNA,miRNA)、长链非编码RNA (long non-coding RNA,lncRNA)、环状RNA (circular,circRNA)和其他ncRNA在恩杂卢胺耐药进展中的调控机制,并系统分析其共性,为后续研究提供一定参考思路。

关键词：非编码RNA 前列腺癌内分泌治疗去势抵抗性前列腺癌耐药性

Changes of Precipitation and Extremes and the Possible Effect of Urbanization in the Beijing Metropolitan Region during 1960–2012 Based on Homogenized Observations

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Advances in Atmospheric Sciences 2015年第9期32卷 1173-1185页

作者： LI Zhen YAN Zhongwei TU Kai wu hongyi Key Laboratory of Regional Climate-Environment in Temperate East Asia Institute of Atmospheric Physics Beijing Meteorological Bureau

Daily precipitation series at 15 stations in the Beijing metropolitan region（BMR） during 1960–2012 were homogenized using the multiple analysis of series for homogenization method,with additional adjustments based on analysis of empirical cumulative density function（ECDF） regarding climate *** cumulative density functions of daily precipitation series,the trends of annual and seasonal precipitation,and summer extreme events during 1960–2012 in the original and final adjusted series at Beijing station were comparatively analyzed to show the necessity and efficiency of the new *** indicate that the ECDF adjustments can improve the homogeneity of high-order moments of daily series and the estimation of climate trends in *** linear trends of the regional-mean annual and seasonal（spring,summer,autumn,and winter）precipitation series are-10.16,4.97,-20.04,5.02,and-0.11 mm（10 yr）-1,*** trends over the BMR increase consistently for spring/autumn and decrease for the whole year/summer; however,the trends for winter decrease in southern parts and increase in northern *** affects local trends of precipitation amount,frequency,and intensity and their geographical *** the urban-influenced sites,urbanization tends to slow down the magnitude of decrease in the precipitation and extreme amount series by approximately-10.4% and-6.0%,respectively; enhance the magnitude of decrease in precipitation frequency series by approximately 5.7%; reduce that of extremes by approximately-8.9%; and promote the decreasing trends in the summer intensity series of both precipitation and extremes by approximately 6.8% and51.5%,respectively.

关键词： homogenization urbanization precipitation extremes MASH ECDF