Transnational companies as a source of skill upgrading: The electronics industry in Ho Chi Minh City

Employment and training in TNCs constitute a potential route through which FDI-led industrialization can contribute to national and regional development and economic growth. The article explores this link through the case of TNCs in the electronics industry in Ho Chi Minh City, Vietnam. The skill upgrading contribution of TNCs is related to the type of factories located in Vietnam and the role they play in regional production networks using a model combining the reverse product cycle and regional waves of FDI. Most electronics factories in Vietnam are ‘reproduction factories’ with mature technology and a narrow role in basic component manufacturing; it is shown that their contribution to skill upgrading is correspondingly narrow. Training for the majority of employees is very simple, and those who receive additional training do this especially in labour management, not in technical fields. Only a small group of engineers receive advanced technical training, in Vietnam and in the parent company abroad. The best prospects for increased skill upgrading are found in those companies that are more than reproduction factories for assembly; however, such companies are still few. The TNCs also represent a potential contribution to skill upgrading in local firms through supplier linkages and movement of staff, but when they operate in isolation from a local economy with little absorptive capacity, as in this case, this potential is not realized.     

非量测相机航空摄影航线设计及应用

采用非量测相机进行航空摄影是目前对于应急及在困难地区获取航空影像的有效方法之一,其便于在小型机平台上搭载,具备重量轻、体积小、探测精度高的特点。通过在南极航摄实践,阐述非量测相机应用经验,介绍航线设计、作业方法和技术指标。     

序列无人机影像拼接方法研究

无人机影像具有数量多、畸变大、POS数据不准确等特点,导致其在拼接过程中会产生大量的累积误差,要快速地获得大范围准确的全景图有一定的困难。基于此,提出一种既精确又高效的无人机序列影像拼接方法。首先计算大致的影像匹配区域,减少特征搜索和匹配的时间,同时记录匹配区域中心位置的特征点坐标,引入平差理论,区分平地、丘陵、山区等不同区域加权纠正匹配特征点的坐标位置。同时针对航带间重叠率小、姿态差异大等特点,采用"先航带间再航带内、旁边航带向中间航带靠拢"的拼接方式,减少整体区域的累积误差产生,最终完成全局影像的拼接。     

AMDAR温度观测的误差统计特征分析

观测资料的误差结构特征是影响资料同化效果的重要因素之一,在GRAPES资料同化系统中使用的观测资料误差结构特征是借鉴国外的同化系统或参考文献,没有直接使用实际观测资料统计。因为同化系统的差异和观测系统的不断改进,观测资料误差结构特征也应随着改变。现在同化系统中的观测误差结构特征不能满足同化系统的精细化要求,比如飞机的观测误差特征没有按飞机标识、纬度带和飞行状态进行区分。为了提高AMDAR资料的应用效果,本文对AMDAR资料的误差特征进行统计分析。通过对比AMDAR资料和NECP再分析资料,分别对全球不同纬度带、不同飞行状态和不同飞行标识两者的温度差异进行统计。本文使用的AMDAR资料是从国家信息中心实时库获取的,资料时段为2013年5—7月。统计结果显示在北半球中纬度(20°~50°N)AMDAR资料最密集的区域,AMDAR资料的温度偏差最大,约-2~-1℃,标准差约1.2~1.6℃。温度的标准差在不同飞行状态随纬度而异,赤道地区(20°S~20°N)平飞状态最小,约0.8℃,北半球高纬度(50°~90°N)平飞状态最大,约1.5~2℃。通过分析AMDAR资料的误差特征,可以更有针对性地做好AMDAR资料质量控制及偏差订正,改进同化预报效果。     

Interactions of large meteoroids and small interplanetary bodies with the Earth's atmosphere: Theories and observational constraints

Problems of hypervelocity interaction of large bodies with the Earth's atmosphere has attracted more attention during last few years. Several new concepts of dynamical explosive fragmentation of strong interplanetary bodies at extremely low heights under dynamic pressures of hundreds of Mdyn/cm² were published. Comparison of these theoretical models with precise observations has not yet been done, because data on atmospheric penetration of large bodies are not available.Single body theory with sudden gross-fragmentation was successfully applied to photographic observations of fireballs. The largest bodies observed have sizes up to several meters. The highest dynamic pressure acting on these observed bodies reached slightly over 100 Mdyn/cm². All these photographed fireballs follow theoretical concepts of motion of either the single-body or the single-body with gross-fragmentation under dynamic pressures in the range from 1 to 12 Mdyn/cm². When this theory has been applied to photographic observations, typical standard deviation of the distance flown in the trajectory has been found in a range of 10 to 30 m for one observed distance corresponding also to the geometrical precision of the observations. This model can explain all good observations of atmospheric trajectories of meteoroids up to initial sizes of several meters with high precision. Also the three photographed and one videorecorded meteorite falls fit to this concept completely.The most important phenomenon of atmospheric motion of meteoroids up to several meters in size is the ablation with final stage of hot vapor from ablated material. Spectral records of meteoroids up to several meters in size, down to a height of 16 km and for various velocities show overwhelming radiation of rather low excited metalic atoms (several eV; temperatures 3000 to 5000 K) in the pass-band of visible light. Radiation from high excited atoms of either atmospheric or ablational origin forms only an insignificant part of visible radiation.Contrary to this regime, theories of very large bodies contain ablation mostly in the form of explosive fragmentation. Ablation at higher heights is negligible. This absence of classical ablation and fragmentation at low dynamic pressures for large bodies (contrary to observations of smaller bodies) brings the body to lower heights without too much change of size and makes thus the dynamic pressure much higher than in reality. In any case the change of body dynamics and radiation going from sizes of several meters (observed regime) to sizes of several tens of meters (hypothetical regime) may be crucial for our understanding of dynamics and radiation of large body penetration through the low atmosphere to the Earth's surface. Observations of atmospheric trajectory of these bodies with sufficiently high precision are extremely needed.     

NASA无人机交通管理系统飞行验证试验概述

随着民用无人机在物流配送、地理信息探测和应急救援等领域的快速发展,美国联邦航空局(FAA)和美国航空航天局(NASA)合作开发了无人机交通管理系统(UTM),并开展了大量的验证试验。根据技术难度,NASA将运行技术和相关的飞行验证试验分为4个技术能力水平阶段,其中第三和第四阶段是UTM试验的核心阶段,也是技术难度最高的2个阶段。论文整理了美国无人机交通管理系统第三和第四技术能力水平阶段的飞行验证试验,根据各项关键技术,对试验内容及运行场景等进行了概述,总结了相关试验经验,对中国无人机运行管理系统的试验设计提出了建议。     

基于Octomap的无人机室内导航可飞行区域分析

无人机在室内飞行时要实现从一点A到另一点B,首先要知道周围环境中的可飞行区域才能实现导航。鉴于此,本文首先利用3ds Max建立室内环境三维模型;然后经过Binvox和Binvox2bt进行数据转换得到Octomap文件;最后经过Octomap处理可得到八叉树网格地图用来分析无人机在室内环境下的可飞行区域。该实验结果清楚地显示了可飞行区域,对无人机室内导航的进一步研究有较大的应用价值。     

基于快速镶嵌的航摄飞行质检方法研究

当前大多数测绘生产单位航摄飞行质量检查基本上依靠传统的人工方法,速度慢、效率低,无法快速形成质量检查报告,不能适应信息化测绘生产的要求。本文从生产实际出发,结合当前数字摄影测量的特点,总结了一套基于数字航空影像自动化快速镶嵌的航摄飞行质量检查方法,并研发原型系统。最后,利用浙江省东南沿海摄区103张航摄影像共3个航带进行验证,试验结果表明,该方法能实现航摄飞行质量的快速检查,并自动输出飞行质量评定报告,基本可以取代传统的人工检查方法。     

A primitive confuciusornithid bird from China and its implications for early avian flight

Confuciusornithids, lived from 120―125 million years ago, form a basal bird group and include the oldest birds with horny beaks. Here we describe Eoconfuciusornis zhengi, gen. et sp. nov. from the Early Cretaceous Dabeigou Formation (131 Ma) in Fengning, Hebei Province, northern China. It repre- sents a new and, more primitive than other known, member of this group and extends the lifespan of this family to 11 Ma, the longest of any known Early Cretaceous avian lineages. Furthermore, Eoconfuciusornis and its relatives present many osteological transformations, such as the size increase of the deltopectoral crest of the humerus and the keel of the sternum, apparently an adaptation toward improved flight in the evolution of the Confuciusornithidae.     

面向资源环境行业需求的多层次复合型地理信息人才培养模式

随着资源环境行业对地理信息人才需求的增加,结合目前地理信息系统专业在人才培养模式上的不足,如培养目标不清晰、课程体系与行业需求不协调、学生实践能力不足和缺乏特色专业教材等,本文提出了面向资源环境行业需求的多层次复合型地理信息人才培养模式,并从课程体系与教学方法、实践教学环节、开放式办学模式、特色专业建设和教师队伍建设等5个方面途径来阐述这一培养模式。