摘要：针对分布式位置大数据收集导致的信息孤岛问题和位置隐私泄露面临的风险,提出一种基于联邦学习的位置大数据统计预测与隐私保护方法。首先,构建基于横向联邦学习的位置大数据统计预测发布框架,该框架允许各行政区域的数据收集者保留各自的原始数据,并使多个参与方通过交换训练参数来协同完成预测模型的训练任务;其次,针对具有时空序列特性的位置大数据密度统计预测问题,设计PVTv2-CBAM,以提高客户端预测结果的准确性;最后,提出一种差分隐私预算的动态分配和调整算法,并结合MMA(Modified Moments Accountant)机制实现对客户端模型的差分隐私保护。实验结果表明,相较于卷积神经网络(CNN)、长短期记忆(LSTM)网络、卷积LSTM(ConvLSTM)模型,PVTv2-CBAM在Yellow_tripdata数据集和T-Driver轨迹数据集上预测的平均绝对误差分别降低0~62%和39%~44%;所提差分隐私预算动态分配和调整算法在调整阈值为0.3和0.7时,使模型预测的准确率与无动态调整相比分别提高了约5%与6%。以上结果验证了所提方法的可行性和有效性。

摘要：以国产杉木锯材和毛竹展平竹为基材,在施胶量200 g/m^(2),压力0.6 MPa的工艺参数下制备了一种正交胶合竹木(CLBT)。通过三点弯曲试验研究了CLBT在强轴和弱轴两个方向上的抗弯性能,并根据剪切类比理论计算了CLBT在强轴和弱轴方向上的弯曲强度标准值和设计值。结果表明:CLBT在强轴和弱轴方向上的弯曲强度分别为58.19、25.25 MPa,弯曲弹性模量分别为8.54、2.56 GPa,从整体上看,CLBT具有较好的抗弯性能。抗弯试验中CLBT在两个方向上表现出不同的破坏模式,强轴方向主要表现为杉木层滚动剪切以及杉木层与展平竹界面层间剪切破坏,而弱轴方向上主要表现为最底层展平竹层沿轴向受拉断裂以及垂直层的杉木受拉破坏。通过剪切类比理论计算得到,CLBT在强轴方向的弯曲强度标准值和设计值分别为44.17 MPa和21.03 MPa,弱轴方向上其弯曲强度标准值和设计值分别为6.85 MPa和3.26 MPa,达到了ANSI/APA PRG 320-2019中E1等级对抗弯性能的要求。

摘要：Spatiotemporal variation of velocity is impor- tant for debris flow dynamics. This paper presents a new method, the trace projection transformation, for accurate, non-contact measurement of a debris-flow surface velocity field based on a combination of dense optical flow and perspective projection transformation. The algorithm for interpreting and processing is implemented in C ＋＋ and realized in Visual Studio 2012. The method allows quantitative analysis of flow motion through videos from various angles （camera positioned at the opposite direction of fluid motion）. It yields the spatiotemporal distribution of surface velocity field at pixel level and thus provides a quantitative description of the surface processes. The trace projection transformation is superior to conventional measurement methods in that it obtains the full surface velocity field by computing the optical flow of all pixels. The result achieves a 90% accuracy of when comparing with the observed values. As a case study, the method is applied to the quantitative analysis of surface velocity field of a specific debris flow.

摘要：互联网语境下,短视频受众一定程度上掌握了观看的主动权,如何进行短视频广告的创意传播成为亟须解决的问题。本文认为,我国5G落地商用之后,短视频广告更需考虑不同平台属性,契合平台调性;在内容创作上进行反转、夸张、幽默等多种创意手段提升传播原动力;在形式上综合运用新技术不断进行创意嫁接等方式优化和提升传播策略。

摘要：Based on the analysis of the historical background and current situation of the study of Vietnamese Chinese poetry, this paper analyzes the achievements and shortcomings of the existing research. It is found that although there are a large number of authors and achievements in the study of Vietnamese Chinese poetry in the past 40 years, it still stays in the low level of work elaboration and literature review, and lacks of theoretical and systematic research. The main purpose of this article is to analyze the current situation of Vietnamese Chinese poetry research, and to explore the new path and method of Chinese scholars’ research on Vietnamese Chinese poetry through comparative analysis of domestic and foreign research results.

摘要：This paper mainly discusses the diplomatic way of Vietnamese envoys through literature during their mission toChina, including the group, communication mode and reason of the literary exchange between Vietnam envoy andChinese literati. The article points out that the Chinese literati contacted by Vietnamese envoys could be dividedinto Lingnan literati group (Guangdong and Guangxi provinces), Huguang literati group (Hunan and Hubeiprovinces), Jiangnan literati group (Southern Anhui and Jiangsu provinces), and Northern literati group (Henan &Hebei provinces and Beijing). There are three main ways of literary communication between Vietnamese envoysand Chinese literati: the first is to give poems to each other according to fixed rhythm;the second is to communicateby writing;the third is to comment on poems each other. There are two main reasons for the literary exchangebetween Vietnamese envoys and Chinese literati: on the one hand, they wanted to achieve the purpose of “poetrydiplomacy” with literature, and took the initiative to communicate with Chinese literati;on the other hand, Chineseliterati were curious about Vietnamese envoys, so they asked Vietnamese envoys to give poems, or even paid fortheir literary works. The literary exchange between Vietnamese envoys and Chinese literati is a direct reflection ofthe literary exchange between China and Vietnam, from which we can see that the Chinese literature of Vietnam inthe feudal period is an important part of the Chinese cultural circle.

摘要：德育是培养医学生的重中之重,“生理学”是高职医学类课程的专业基础课。当前,该课程教学上存在教师关注课程知识和技能教学,课程思政教学固化的问题,提升教师课程思政教育意识,依托线上教学平台、健康志愿者协会学生社团拓展课程思政的时间空间,以提升职业教育服务教育强国建设的成效。

摘要：An approach to design multi-channel cylinder dryer was proposed. The heat transfer performance and flow characteristic under various structural parameters were analyzed. First, an experiment was designed and set up to measure the condensing heat transfer coefficient and the pressure drop in order to ,~erify the applicability of the Cavallini＇s correlation. Then, the relationship among the count of channels, aspect ratio, spacing ratio, width, height and hydraulic diameter of a channel was given. Finally, the correlation of condensing heat transfer and the homogeneous model was introduced in order to observe the heat transfer performance and flow characteristic of the multi-channel cylinder dryer affected by different structures. The study reveals that the structural parameters including count of channels, aspect ratio, spacing ratio of a channel dramatically influence the condensation heat transfer coefficient and frictional resistance of the steam. Based on the selected paper machine, it is suggested that the overall performance of the multi-channel cylinder dryer is best if the count of channels is 150-200, the aspect ratio is 1 ： 3 and the spacing ratio is 1 ： 1-1 ： 3.

摘要：昆虫群落是生态系统的重要组成,具有环境指示作用。成都市生物资源丰富,城市化进程迅速,对昆虫群落特征的研究有助于理解生态系统稳定性和城市化对生物多样性的影响。2021年4月-2022年11月,在成都市城区、城乡过渡带、郊区3个区域共设置52个调查位点,采用样线法和灯诱法调查了昆虫群落多样性。共采集到2372头昆虫,隶属于15目106科325属401种,物种丰富度较高的目依次为:鳞翅目、鞘翅目、直翅目和半翅目;昆虫群落多样性整体较高,城区、城乡过渡带、郊区的多样性指数(H′)分别为4.06、5.06和6.06,丰富度指数(R)分别为16.42、22.17和35.72,多样性随着远离城市中心而逐渐升高。群落优势种为马铃薯鳃金龟(Amphimallon solstitialis)和鳞翅目的竹弯茎野螟(Crypsiptya coclesalis)和东方菜粉蝶(Pieris canidia),优势种组成在不同区域间有所不同。城市化进程对昆虫群落组成和多样性造成了一定影响,城市建设过程中应考虑实施监测昆虫群落动态、研究昆虫的生态服务功能、设计多样化植物组合、推广生物防治等策略,以利于保持生态系统健康,助力公园城市可持续发展。

摘要：偏差分析主要描述了待分析模型与已知模型之间的变化与偏离,广泛应用于可穿戴产品与人体的距离描述,对于提升可穿戴产品适配度具有重要意义。然而,现有偏差分析软件无法满足耳机适配设计需求,计算耳机与耳朵模型偏差时会在耳朵点云与耳机点云双侧重复计算,导致结果不连续,与真实情况偏差较大。因此,提出了一种适合于耳机佩戴适配度分析的偏差分析算法,能够对干涉集与间隙集进行有效分类,精确计算耳机与耳朵的偏差值。此外,基于耳机佩戴实验,与现有偏差分析软件计算结果进行差异比较。基于与主观不适配度打分的相关性分析,以及工具与算法的可视化效果比对,进行算法的有效性与可用性验证。结果表明,耳机产品偏差分析算法能有效评价耳机产品的适配度,相较于已有偏差分析工具计算效果具有较大提升。