The Research on Multi-Sensors Calibration of Mobile Mapping Systems

人们从外界获取的信息绝大部分来源于视觉。人们通过眼睛将获取的信息传入到大脑，再由大脑对其进行相应的处理与分析。随着传感器与计算机技术的迅速发展，计算机视觉逐渐实现了替代人眼与大脑实现对周围环境的简单识别与理解。计算机视觉的研究目标是让计算机能像人那样通过视觉观察和理解世界，这不仅要求计算机能够感知三维环境中物体的几何信息（物体的形状、位置、姿态等），还需要对它们进行存储、描述、识别与理解。相比于直接在三维环境中通过各种机械量测工具、测角和测距设备等实现三维环境信息的描述、存储等，基于数字摄影测量方法能够获取目标在某个运动状态下的瞬间信息，具有实时、高效、准确、隐蔽等众多优点。 “移动测量系统...Among the information obtained from outside environment, most of them come from human visual perception. The information is delivered from eyes to brain, then analyzed and processed by brain. With the development of the sensors and computer technology, computer vision, which subsitute humans’ cerebra and eyes, can achieve the simple function of environmental recognition and understanding. The aim ...学位：工程硕士院系专业：信息科学与技术学院_计算机技术学号：2302011115306

《授予市民权的优流斯法》的颁布背景及其实施效果

公元前1世纪初的\"意大利\"具有特定的地理和行政意义。生活在\"意大利\"的民众为争取更加公正的待遇,发起了反叛罗马的\"同盟战争\"(也称\"意大利战争\")。在战争爆发一段时间后,罗马为扭转战争局势,于公元前90年颁布《授予市民权的优流斯法》并在其后出台了一些补充规定,为争取战争胜利和巩固战后局面取得了良好的效果。该部法律一方面确立了授予\"意大利\"的民众罗马市民身份的一些规则,另一方面,通过在同盟者城市适用罗马私法规范,客观上为新型罗马自治市的出现奠定了基础,促进了意大利城市和自治市制度的发展

基于GA-GRNN的高速列车头型三维优化设计

针对CRH380A型高速列车头部外形的气动减阻问题, 设计了一种新型的基于自由曲面变形的局部型函数参数化方法, 提出了一套基于实数编码遗传算法的变光滑因子广义回归神经网络响应面模型(GA-GRNN)的气动外形优化方法. 优化结果表明: 局部型函数参数化方法操作简单、实现方便, 使用少量的设计参数可以控制较大变形区域, 且能保证变形的光顺性和不同变形区域间的光滑过渡; 使用同样的样本点进行训练, GA-GRNN 比GRNN的预测精度高, 更容易得到全局最优解; 优化后, CRH380A 三辆编组简化外形气动阻力减小8.7%, 本文提出的优化设计方法简单、高效, 为高速列车气动外形的工程优化设计提供了新思路

Measurement of heat flux distribution of supercritical kerosene fueled supersonic combustor

Heat flux distribution of supercritical kerosene fueled, single-side expanded supersonic combustor with two dislocated cavities was experimentally studied. The effects of inlet Mach number, total temperature, mass flow rate and fuel equivalence ratio on the combustion and heat transfer characteristics in the supersonic combustor were analyzed. The isolator inlet Mach number is 2.0 and 2.5, the total temperature is 1305 K to 1701 K and the mass flow rate is 2.0 kg/s to 3.0 kg/s. Pilot hydrogen and liquid or supercritical (773±20 K) China No.3 kerosene were injected in front of the cavities with the equivalence ratio ranges from 0.52 to 0.88. Results show that heat flux increases with the inlet temperature and mass flow rate, however, the influence of equivalence ratio is non-monotonic in the range of this study. The two inlet Mach numbers also trigger different combustion modes, which further complicates the heat flux distribution. In the end, a three parameter correlation is proposed and fitted to normalize the experiment results for comparison and discussion. © 2016, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved

国内高速列车气动噪声研究进展概述

随着运行速度的提升,气动噪声逐渐成为高速列车最主要的噪声源,并极有可能成为新设计高速列车的一个技术瓶颈。开展高速列车气动噪声研究,明晰高速列车气动噪声机理与规律,发展低噪声高速列车外形设计对更高速度级的高速列车研发具有重要意义。本文主要对自2010年以来国内进行的高速列车气动噪声研究进行梳理总结。首先详细介绍了高速列车气动噪声研究采用的一系列方法,主要从实车试验、风洞实验以及数值模拟方法三个方面展开。在掌握高速列车气动噪声研究方法的基础上,进而探讨了当前高速列车气动噪声研究的现状,重点就高速列车气动噪声源识别、主要噪声源机理与特性、噪声源优化等方向进行了阐述,并明确了当前研究获得的一些主要结论。最后简要探讨了高速列车气动噪声未来可能的研究方向

2016年夏季南海海盆水体颗粒物粒径分布特征

颗粒物粒径分布（Particle Size Distribution,PSD）代表了颗粒物浓度与颗粒物粒径之间的关系,影响着海洋生态环境和水体光学特性等。文章基于2016年夏季航次调查的生物光学剖面数据,研究了南海海盆海域PSD的分布特征。研究发现,幂律函数可以较好地拟合南海海盆区域的PSD,对数空间中的实测的PSD与模拟的PSD平均决定系数高达0.95。PSD斜率（ξ）的分布范围为[1.27,7.65],均值为3.93±0.56。南海海盆区域表层水体的ξ均值与全球大洋表层水体的ξ均值相近,但高于海湾等表层水体的ξ均值。ξ能较好地表征颗粒物平均粒径DA的大小,两者存在明显负相关关系,即ξ值越高,DA越小;反之,DA越大。通过分析T1断面的生物光学剖面数据及总体平均的PSD剖面数据,发现PSD剖面分布特征如下:1)表层水体的ξ值相对较高,且DA值相对较低,推测可能是由于微微型藻类为主导颗粒物所致;2)ξ值极小值层出现在次表层叶绿素浓度极大值层（Subsurface Chlorophyll Maximum Layer,SCML）中,并伴随DA极大值层的出现,其原因可能是SCML中的大粒径浮游植物占比显著增加;3)弱光层中的ξ值较SCML中的高,但略低于表层的ξ值,而DA则位于表层与SCML的DA之间,这可能与浮游植物及其碎屑的絮凝、分解、沉降等过程相关。PSD特征影响着海水的固有光学特性,分析发现:由于SCML中的叶绿素浓度增加,颗粒物散射系数（bp（532））和颗粒物后向散射系数(bbp（532）)也相应呈现显著增加的趋势。弱光层中的平均bp（532）与平均bbp（532）最小。ξ与颗粒物衰减光谱斜率之间呈高分散性,Boss等（2001b）的模型适合用于粗略估算区域性的ξ分布范围及均值。国家自然科学基金(41576030,41431176,4176045,4176044,41376042);;热带海洋环境国家重点实验室自主研究项目(LTOZZ1602);;广州市科技计划重点项目(201504010034,201707020023,201607020041);;广东省科技计划重点项目(2016A020222008);;中科院A类先导专项(XDA11040302)~

典型路基结构对高速列车横风气动特性影响分析

由于地域及环境的限制, 高速铁路采用多种路基结构如平直地面、不同高度路堤、高架桥等,当列车运行在路堤及高架桥上时,车体周围的绕流流场比平直地面更加复杂。在强横风的作用下,不同的路基结构上的高速列车横风气动特性存在明显差异,不合理的路基结构将影响列车的横风安全性。同时列车结构复杂,转向架、受电弓等都对列车的流场特性有重要作用,过于简化的短编组列车外形不能够精细反映列车的真实气动特性。为研究典型路基结构对高速列车横风气动特性的影响,以9编组动力集中型高速列车实车为研究对象,考虑风挡、转向架、受电弓等细节特征,对列车运行速度为200 km/h,横风速度分别为20 m/s、30 m/s、35 m/s、40 m/s,路基结构分别为平直地面、3 m路堤、6 m路堤、高架桥等四种场景下的高速列车空气动力学性能进行了仿真计算和对比,分析了不同路基地面条件下列车的横风气动特性的差异及规律,为横风条件下复杂路基结构的列车运行安全控制提供了参考

Influences of affiliated components and train length on the train wind

The induced airflow from passing trains, which is recognized as train wind, usually has adverse impacts on people in the surroundings, i.e., the aerodynamic forces generated by a high-speed train&#39;s wind may act on the human body and endanger the safety of pedestrians or roadside workers. In this paper, an improved delayed detached eddy simulation (IDDES) method is used to study train wind. The effects of the affiliated components and train length on train wind are analyzed. The results indicate that the affiliated components and train length have no effect on train wind in the area in front of the leading nose. In the downstream and wake regions, the longitudinal train wind becomes stronger as the length of the train increases, while the transverse train wind is not affected. The presence of affiliated components strengthens the train wind in the near field of the train because of strong flow solid interactions but has limited effects on train wind in the far field.</span

溶菌酶1在小鼠超数排卵前后孵化及休眠囊胚中差异表达的研究

目的研究溶菌酶1(lysozyme 1,LYZ1)基因在超数排卵前后小鼠孵化囊胚和休眠胚胎中的分布以及表达,探究动物胚胎着床过程中新的调节机制。方法从妊娠5 d ICR小鼠体内获取的正常孵化囊胚和超排囊胚,利用小鼠延迟着床模型于妊娠第8天获取休眠胚胎和超排休眠胚胎。利用免疫荧光和Western Blot方法检测LYZ1蛋白在四组胚胎中的分布和差异表达变化。结果 LYZ1在超数排卵前、后小鼠孵化囊胚和休眠胚胎中均有表达,且主要集中在内细胞团中,滋养层细胞和胞质中少见分布;与未进行超排的小鼠相比,LYZ1蛋白在超排后小鼠胚胎中表达量显著上调,与未营造休眠模型的小鼠相比,LYZ1蛋白在休眠模型小鼠胚胎中的表达量显著上调。结论 LYZ1蛋白在囊胚内细胞团中表达,可能参与调节胚胎内细胞团的发育;LYZ1蛋白在超排-休眠胚胎中的高表达,说明LYZ1蛋白在休眠和超数排卵的双重影响下,会因为抵御不利环境而上调。2016年度科技创新服务能力建设-科技计划重点项目(KZ201610020018);;2018科技创新服务能力建设(KZ201610020018)~

Parametric design and optimization of high speed train nose

Aiming at shortening the design period and improve the design efficiency of the nose shape of high speed trains, a parametric shape optimization method is developed for the design of the nose shape has been proposed in the present paper based on the VMF parametric approach, NURBS curves and discrete control point method. 33 design variables have been utilized to control the nose shape, and totally different shapes could be obtained by varying the values of design variables. Based on the above parametric method, multi-objective particle swarm algorithm, CFD numerical simulation and supported vector machine regression model, multi-objective aerodynamic shape optimization has been performed. Results reveal that the parametric shape design method proposed here could precisely describe the three-dimensional nose shape of high speed trains and could be applied to the concept design and optimization of the nose shape. Besides, the SVM regression model based the multi-points criterion could accurately describe the non-linear relationship between the design variables and objectives, and could be generally utilized in other fields. No matter the simplified model or the real model, the aerodynamic performance of the model after optimization has been greatly improved. Based on the SVR model, the nonlinear relation between the aerodynamic drag and the design variables is obtained, which could provide guidance for the engineering design and optimization