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基于神经网络的HEVC帧间预测方法及其硬件研究

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中国集成电路 2024年第4期33卷 75-81页

作者：陶乐溪施隆照福州大学物理与信息工程学院

相比于H.264,高效视频编码标准(HEVC)提出了许多新技术,提高了编码性能,但是也显著提高了编码复杂度。本文从硬件实现的角度出发,对已有的帧间CU划分预测神经网络的结构进行了多方面的优化,使其参数减少了70%,加法和乘法运算分别减少了... 详细信息

相比于H.264,高效视频编码标准(HEVC)提出了许多新技术,提高了编码性能,但是也显著提高了编码复杂度。本文从硬件实现的角度出发,对已有的帧间CU划分预测神经网络的结构进行了多方面的优化,使其参数减少了70%,加法和乘法运算分别减少了60%、58.2%。并对优化后的卷积神经网络参数采用10位定点数方案进行定点化处理,进一步有效减少硬件资源的开支。对比于HEVC参考软件(HM16.5),优化后网络引起的BD-BR和BD-PSNR平均损失为1.718%和-0.056dB,平均节省35%~52%的编码复杂度,并且定点化处理后引起的性能损失可忽略不计。

关键词： HEVC 帧间预测卷积神经网络低复杂度神经网络定点化

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循环流化床灰的物理特性及力学性能试验研究

公路 2024年第4期69卷 280-285页

作者：邓小鹏任希庆王小敏山西能源学院晋中市030600 汾阳市交通运输局吕梁市032200

循环流化床灰与煤粉炉粉煤灰在物理特性及力学性能上有较大差别,阻碍了其大规模的利用,为解决循环流化床灰路基填料的合理利用问题,采用激光粒度检测仪、XRD、SEM及室内试验测试手段,对循环流化床灰的颗粒特征、物相组成、微观结构及路... 详细信息

循环流化床灰与煤粉炉粉煤灰在物理特性及力学性能上有较大差别,阻碍了其大规模的利用,为解决循环流化床灰路基填料的合理利用问题,采用激光粒度检测仪、XRD、SEM及室内试验测试手段,对循环流化床灰的颗粒特征、物相组成、微观结构及路用力学性能进行了研究。研究结果表明:循环流化床灰的粒度主要分布在10~80μm,矿物成分主要为石英、硫酸钙等,没有莫来石;微观结构上,循环流化床灰颗粒表面凸凹不平,呈现不规则、扁平状的疏松形态,能形成较多的吸水孔隙,致使循环流化床灰在击实试验中需水量较大,最优含水量达38.6%;CBR值、回弹模量及抗剪强度均与压实度呈现较好的线性增长关系,随着压实度增大,CBR值、回弹模量及抗剪强度均会增长,但CBR值的增长幅度更大;当压实度达到92%后,循环流化床灰的抗剪强度随压实度的增加强度增长不显著。

关键词：路基工程循环流化床灰物理特性 CBR值回弹模量抗剪强度

微量元素对超大线能量EH36船板热影响区粗晶区组织和性能的影响

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焊接学报 2024年第2期45卷 47-53,I0005,I0006页

作者：韩美张熹马青军魏玉顺韦晨王泽军贾云海钢铁研究总院北京100081 国家特种设备焊接材料产品质量检验检测中心(天津) 天津300350 天津市特种设备监督检验技术研究院天津300350 天津大桥焊材集团有限公司天津300381

通过焊接热模拟研究了在超大线能量下焊接时Al元素、Mg元素和Ti元素含量对EH36高强船板钢热影响区粗晶区组织、性能的影响规律,采用Thermo-Calc热力学计算与SEM,EDS测试相结合的方法揭示了Al元素、Mg元素和Ti元素含量与母材中氧化物类... 详细信息

通过焊接热模拟研究了在超大线能量下焊接时Al元素、Mg元素和Ti元素含量对EH36高强船板钢热影响区粗晶区组织、性能的影响规律,采用Thermo-Calc热力学计算与SEM,EDS测试相结合的方法揭示了Al元素、Mg元素和Ti元素含量与母材中氧化物类型、尺寸、数量及粗晶区相变的关系.结果表明,Al_(2)O_(3)无法诱导针状铁素体相变,当Al元素质量分数低于0.005%时,钢中可形成Mg元素、Ti元素或其复合氧化物,可促进粗晶区针状铁素体相变.Mg元素和Ti元素联合添加时,当Mg元素质量分数由0.0042%降低为0.0013%,氧化物类型由MgO转变为Mg_(2)TiO_(4),经统计20个视场内的氧化物数量由408个提高到503个,平均直径由1.37μm减小到1.10μm,显著提高了非均匀形核的比表面积,抑制了晶界铁素体的形成,使t8/5=300 s时粗晶区热模拟试样-20℃冲击吸收能量由43 j提升到127 j.

关键词：微量元素船板超大线能量热影响区粗晶区

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journal of Systems Engineering and Electronics 2020年第6期31卷 1167-1177页

作者： PENG Han CHENG Ting LI xi School of Information and Communication Engineering University of Electronic Science and Technology of ChinaChengdu 611731China

In target tracking applications,the Doppler measurement contains information of the target range rate,which has the potential capability to improve the tracking ***,the nonlinear degree between the measurement and the target state increases with the introduction of the Doppler ***,target tracking in the Doppler radar is a nonlinear filtering *** order to handle this problem,the kalman filter form of best linear unbiased estimation(BLUE)with position measurements is proposed,which is combined with the sequential filtering algorithm to handle the Doppler measurement further,where the statistic characteristic of the converted measurement error is calculated based on the predicted information in the sequential ***,the algorithm is extended to the maneuvering target tracking case,where the interacting multiple model(IMM)algorithm is used as the basic framework and the model probabilities are updated according to the BLUE position filter and the sequential filter,and the final estimation is a weighted sum of the outputs from the sequential filters and the model *** results show that compared with existing approaches,the proposed algorithm can realize target tracking with preferable tracking precision and the extended method can achieve effective maneuvering target tracking.

关键词： kalman filter best linear unbiased estimation(BLUE) measurement conversion sequential filter

μ-Synthesis control with reference model for aeropropulsion system test facility under dynamic coupling and uncertainty

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Chinese journal of Aeronautics 2023年第10期36卷 246-261页

作者： jiashuai LIU xi WANG xi LIU Meiyin ZHU xitong PEI Song ZHANG Zhihong DAN School of Energy and Power Engineering Beihang UniversityBeijing 100191China Zhongfa Aviation Institute Beihang UniversityHangzhou 311115China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China Science and Technology on Altitude Simulation Laboratory AECC(Aero Engine Corporation of China)Sichuan Gas Turbine EstablishmentMianyang 621703China

Due to the dynamic coupling and multi-source uncertainties,it is difficult to accurately control the pressure and temperature of the Aeropropulsion System Test Facility(ASTF)in the presence of rapid command and large *** paper presents the design ofμ-synthesis control to solve the *** incorporating the pressure ratio into the linear equation of the control valve,the modeling error of ASTF in the low frequency range is effectively ***,an uncertain model is established by considering various factors,including parameter variations,modeling error in the low frequency range,unmodeled dynamics,and changes in the working *** address the dynamic coupling,a diagonal reference model with desired performance is incorporated intoμ-***,all weighting functions are designed according to the performance ***,theμ-controller is obtained by using the standardμ-synthesis *** results indicate that theμ-controller decouples the pressure and temperature dynamics of *** with the multivariable PI controller,integral-μcontroller,and double integral-μcontroller,the proposedμ-controller can achieve higher transient accuracy and better disturbance ***,the robustness of theμ-controller is demonstrated by Monte Carlo simulations.

关键词： Aeropropulsion System Test Facility(ASTF) Decoupling Robustness μ-Synthesis Uncertainty

闭口呼吸对提高高流量呼吸湿化治疗仪改善呼吸衰竭疗效的研究

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中国医疗器械信息 2024年第8期30卷 32-34页

作者：吴军陈曦阳光南平市第二医院福建南平354200

目的:探讨闭口呼吸对提高高流量呼吸湿化治疗仪改善呼吸衰竭的疗效。方法:选择2021年9月~2023年10月南平市第二医院呼吸内科呼吸衰竭患者300例为对象,信封法分为两组各150例。两组采用经鼻高流量呼吸湿化治疗仪治疗,对照组予以未闭口呼... 详细信息

目的:探讨闭口呼吸对提高高流量呼吸湿化治疗仪改善呼吸衰竭的疗效。方法:选择2021年9月~2023年10月南平市第二医院呼吸内科呼吸衰竭患者300例为对象,信封法分为两组各150例。两组采用经鼻高流量呼吸湿化治疗仪治疗,对照组予以未闭口呼吸,观察组是严格闭口呼吸,比较两组干预效果。结果:治疗后观察组患者出现胸闷、气促、呼吸困难、发绀的评分均低于对照组患者(P<0.05);两组干预后血气指标得到改善;观察组PaCO_(2)低于对照组(P<0.05)、PaO_(2)及SaO_(2)高于对照组(P<0.05);观察组患者改善时间、通气天数及住院天数均低于对照组患者(P<0.05);观察组并发症发生率低于对照组(P<0.05)。结论:在高流量呼吸湿化治疗仪治疗呼吸衰竭中采取闭口呼吸可有效改善血气水平、血氧饱和度情况,改善患者临床症状,有效缩短症状改善时间、住院天数,同时降低并发症发生率。

关键词：闭口呼吸高流量呼吸湿化治疗仪呼吸衰竭血气水平血氧饱和度

Criteria of limiting temperature and parametric analysis of the large deflection behavior for fully restrained steel beams in fire

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Science China(Technological Sciences) 2012年第1期55卷 264-275页

作者： xi Feng LUAN YanPing Shandong Provincial key Laboratory of Structural Engineering School of Civil Engineering Shandong Jianzhu University Jinan 250101 China School of Civil Engineering Shandong Jianzhu University Jinan 250101 China

This paper mainly involve 3 parts:1) To apply the minimum principle of acceleration in dynamics of elastic-plastic continua at finite deformation to the statics problems,a computing model is presented for the restrained steel beams exposed to the *** this model,both effects of large deflection and thermal expansion deformation are taken into account,and the constitutive equations with the temperature effects are *** a dynamic finite difference(DFD) method is presented by using the dis-crete technique,which can be used in simulating the response of the steel beams at elevated temperature,and the large deflec-tion behavior and catenary action effects of the beams can be adequately *** primary numerical results show that the method is valid and *** with other methods,this technique is very simple,and it can also be further devel-oped to simulate the behavior of steel beams subjected to the coupling loading of explosion and fire when both effects of strain rate and inertia are considered.2) By using this DFD method,detailed parametric analysis are presented so as to check the consistency of response results for several different formulas of thermal expansion deformation and retention factors of steel at elevated temperature,the influence of these parameters on the critical temperature is examined.3) Based on the analysis for the curves of temperature-generalized yield function comprised by the axial force and bending moment,both criteria to determine the limiting temperature(or failure temperature) of large deflection steel beams are presented more explicitly,that is,both lim-iting temperatures can be determined by if the catenary force begins to appear or arrives at the maximum value,*** is shown by numerical results that both limiting temperatures are close to the both critical temperatures which are correspond-ing to the maximum deflections equal to span/20 and span/10,*** conclusion may be helpful to make r

关键词： steel beam fire DFD method large deflection parametric analysis limiting temperature criteria yield function

Anomalous Hall effect,magneto-optical properties,and nonlinear optical properties of twisted graphene systems

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npj Computational Materials 2020年第1期6卷 1172-1181页

作者： jianpeng Liu xi Dai Department of Physics Hong Kong University of Science and TechnologyKowloonHong KongChina

We study the anomalous Hall effect,magneto-optical properties,and nonlinear optical properties of twisted bilayer graphene aligned with hexagonal boron nitride substrate,as well as twisted double bilayer graphene *** show that non-vanishing valley polarizations in twisted graphene systems would give rise to the anomalous Hall effect,which can be tuned by in-plane magnetic *** valley polarized states are also associated with giant Faraday and kerr rotations in the terahertz frequency ***,we propose that the twisted graphene systems exhibit colossal nonlinear optical responses by virtue of the inversion-symmetry breaking,the small bandwidth,and the small excitation gaps of the *** twisted double bilayer graphene,we find that certain components of the nonlinear photo-conductivity tensor are directly proportional to the orbital magnetization of the system,which would exhibit remarkable hysteresis behavior in response to perpendicular magnetic fields.

关键词： twisted nonlinear hexagonal

表面组装抗生素的磁性四氧化三铁纳米材料及抗菌性能研究

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化工新型材料 2024年第2期52卷 239-245页

作者：汪熙吴娟滕业方臧依桐蔡思雨常州工业职业技术学院材料工程学院常州213001 江苏理工学院化工与环境学院常州213164

采用溶剂热法制备了聚丙烯酸修饰的Fe_(3)O_(4)纳米材料,并采用层层静电自组装法在非二维平面的纳米颗粒上组装氨基糖苷类抗生素庆大霉素和酸性粘多糖透明质酸。利用透射电镜观察纳米表面形貌,采用热重分析仪和X射线衍射仪研究材料结构... 详细信息

采用溶剂热法制备了聚丙烯酸修饰的Fe_(3)O_(4)纳米材料,并采用层层静电自组装法在非二维平面的纳米颗粒上组装氨基糖苷类抗生素庆大霉素和酸性粘多糖透明质酸。利用透射电镜观察纳米表面形貌,采用热重分析仪和X射线衍射仪研究材料结构和物相组成,通过傅里叶红外光谱仪、X射线光电子能谱仪、Zeta电位仪和振动磁强计分析了其表面理化性质和磁性性能。抗菌实验结果表明,外加磁场作用有效改善了材料渗透细菌生物膜的效率,显著提高了抗生物膜的靶向性和抗生素的药物利用度,在治疗细菌感染方面展现出良好的应用前景。

关键词： Fe_(3)O_(4) 磁性抗生素抗菌抗生物膜