珊瑚礁地形上胸墙波浪力大水槽试验

基于大比尺波浪水槽试验,开展了珊瑚礁地形上的波浪与斜坡堤相互作用试验。在不同水深和波浪条件下测量斜坡堤胸墙的水平力和浮托力,并与规范值进行对比。试验结果表明:胸墙的波浪力受波浪破碎后的堤前壅水、破碎波高和水流冲击的共同影响;胸墙水平力呈矩形分布,浮托力呈三角形分布;由于波浪在珊瑚岛礁上传播过程中的能量耗散,平均水平力和前趾浮托力试验结果均小于采用深水波要素计算的规范值,所提出的基于胸墙距礁缘的相对距离和礁盘上相对水深的波浪力修正系数,修正后的公式计算结果与试验值吻合较好。     

A TEST FOR SPHERICITY OF ERRORS IN LINEAR MODELS

1.IntroductionConsideragenerallinearmodelwhereyisannx1vectorofobservations,Xisannxpdesignmatrixwithrankp,Pisapx1vectorofparameters,e~(el,'',e.)'isavectorofrandomerrors.Inthestatisticalliterature,itisoftenassumedthatei,i~1,'')ushavetheindependentnormaldi…     

Improved anovae of the covariance matrix in general linear mixed models

In this paper, the problem of estimating the covariance matrix in general linear mixed models is considered. A new class of estimators is proposed. It is shown that this new estimator dominates the analysis of variance estimate under two squared loss functions. Finally, some simulation results to compare the performance of the proposed estimator with that of the analysis of variance estimate are reported. The simulation results indicate that this new estimator provides a substantial improvement in risk under most situations.     

混合现实军事装备维修系统综述

混合现实维修具有低成本、低风险、高效率的独特优势,是军事装备保障领域的研究热点。介绍了混合现实技术的概念,说明了混合现实维修系统的组成结构和关键技术;阐述了混合现实在军事装备教学训练、战场抢修与智能维修中的应用,重点分析了存在的问题,并给出了解决思路;最后指出了系统智能化、标准化、模块化的发展趋势,并为其在我军的运用提出了意见。     

GENERALIZED p-VALUES AND GENERALIZED CONFIDENCE INTERVALS FOR VARIANCE COMPONENTS IN GENERAL RANDOM EFFECT MODEL WITH BALANCED DATA

Various random models with balanced data that are relevant for analyzing practical test data are described, along with several hypothesis testing and interval estimation problems concerning variance components. In this paper, we mainly consider these problems in general random effect model with balanced data. Exact tests and confidence intervals for a single variance component corresponding to random effect are developed by using generalized p-values and generalized confidence intervals. The resulting procedures are easy to compute and are applicable to small samples. Exact tests and confidence intervals are also established for comparing the random-effects variance components and the sum of random-effects variance components in two independent general random effect models with balanced data. Furthermore, we investigate the statistical properties of the resulting tests. Finally, some simulation results on the type Ⅰ error probability and power of the proposed test are reported. The simulation results indicate that exact test is extremely satisfactory for controlling type Ⅰ error probability.     

黄河干流水库联合调度规则模型研究

通过水库联合调度模型计算，在求出水库群长期满意的运行策略基础上，分析影响决策水库放水流量的多种因素，归纳出黄河干流各水库调度规则模型。经联合调度运行的检验，获得较满意的结果。此规则模型可反映多种影响因素与水库放水流量之间的关系；结合径流和用水预报，可用于指导水库联合实施调度；有利于今后水库联调的自动控制和自动化管理。     

粗粒料“空间准滑面”模型及其在高面板坝三维分析中的应用

本文在松冈元“空间准滑面”模型的基础上对粗粒料三维本构关系模型做了合理的发展。该模型考虑了高压下颗粒破碎引起模型参数和破坏准则随平均正应力或固结压力而变化的特性、剪缩剪胀特性、以及中主应力对变形的影响,从而有可能推广应用于混凝土面板堆石坝三维应力应变分析。参数可由大型常规三轴压缩试验测定,也可由邓肯-张E～B或E～u模型参数换算求得,便于工程单位使用。通过天生桥面板坝三维计算,所得结果比较合理,基本上符合实际,说明该模型是适用的,有较好的发展前途。     

基于Mask R-CNN的防波堤复杂护面块体检测和分割方法

针对斜坡式防波堤护面层块体个数统计效率和精确率低的问题,提出了基于Mask R-CNN深度学习网络的斜坡式防波堤扭王字块体的识别和分割方法。该方法利用Mask R-CNN深度学习网络学习实验室采集图像的特征信息,通过调整交并比(IOU)阈值得到评价指标最好的模型,并将该模型应用于现场防波堤图像护面块体的识别和分割。测试结果表明,IOU取0.5时,目标分割的平均精确率为91.83%,平均召回率为92.94%;将训练得到的网络用于识别无人机航拍现场的防波堤图像,扭王字块识别率可达90.7%,且拍摄角度和高度对识别精度影响不大。Mask R-CNN深度学习网络可实现密集、复杂护面块体的准确识别,具有良好的移植性和通用性。     

土石坝空间非线性和弹塑性的应力应变分析

本文采用非线性弹性的邓肯-张模型和我们提出的分部屈服模型,编制了TDAD三维非线性程序,对典型河谷土石坝进行了三维和二维的应力应变计算及比较分析,并对铜街子水电站土石坝做了三堆的非线性弹性和弹塑性的计算及分析,取得了比较圆满的结果。