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81.
“7.16”大连新港溢油事故是建国以来大连市最严重的溢油事件.事故发生后,政府积极利用遥感技术对油污信息和清污效果进行了监测.环境小卫星是我国自主研制的卫星星座,具有较高的时间和空间分辨率,能够基本满足油污清除需求.在溢油应急期间,尽管天气条件比较恶劣,环境小卫星依然获取了6景影像数据,有效地掌握了油污分布和清污情况.随着环境小卫星星座的最终建成,完全可以胜任包括溢油监测在内的众多环境灾害监测任务.  相似文献   
82.
郭保臣  任冰  刘明 《水道港口》2011,32(3):168-172
通过对海洋结构物在波浪冲击作用下动力响应的试验研究,分析了波浪冲击作用下结构物最大动力响应及出现的时间。基于Fourier变换的频谱分析,得到了波浪冲击荷载作用下平台结构的水平和竖向振动特性。当入射波频率接近平台水平固有频率时,在水平方向会产生共振。结构物模型竖向刚度较大,试验中竖向不发生共振。  相似文献   
83.
为解决谐波和间谐波参数估计受噪声影响的难题,从被检测信号噪声的基本特性出发,提出了一种基于现代互谱、总体最小二乘、旋转不变参数估计和改进普罗尼技术的谐波和间谐波参数估计新方法.该方法采用互谱技术处理不同采样序列的互相关矩阵;根据不同时刻白噪声相互独立的原理划分信号子空间和噪声子空间,并结合总体最小二乘与旋转不变参数估计判定被检测信号的频率;最后,根据白噪声均值为0的特性,采用改进普罗尼技术估计信号分量的幅值和初始相角.仿真结果表明,该方法在低信噪比环境下可检测出多个子信号,且频率的相对误差均小于0.4%,而耗时仅0.058 s,具有良好的估计精度和估计效率.  相似文献   
84.
掺杂种类和掺杂量的不同可使聚苯胺的光学性质发生很大的变化.利用盐酸挥发的HCl气体对聚苯胺自支持薄膜进行了掺杂,并测量了不同掺杂浓度的薄膜在不同入射角下的红外反射谱(4000cm-1~400cm-1).结果表明:掺杂使干涉程度明显减弱、干涉峰向长波方向移动、反射率先上升后下降,而且不同入射角反射谱的相对强度也会有一定程度的改变.通过实测数据分析与计算机模拟对比证明:在低掺杂浓度时,随着掺杂程度的提高,消光系数上升较快,当掺杂浓度较高时,消光系数上升缓慢;在整个掺杂过程中,折射率基本保持一个较慢的上升趋势.  相似文献   
85.
针对船舶制造现场缺乏实时感知系统、船舶制造车间未构建数据传输至工位的通信系统等问题,应用网络构建技术和信息采集与传输技术,构建船舶智能感知车间网络,实现船舶制造车间内部的“人、机、料”互联,达到数据采集的多源异构性和实时性,提高设备综合利用率和船厂管理水平。  相似文献   
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Terrain physical characteristics can have a significant impact on passenger vehicle handling, ride quality, and stability. Here, an algorithm is presented to classify terrain using a single suspension-mounted accelerometer. The algorithm passes a measured acceleration signal through a dynamic vehicle model to estimate the terrain profile, and then extracts spatial frequency components of this estimated profile. A method is introduced to identify and remove terrain impulses from the profile that are caused by ruts and potholes. Finally, a supervised support vector machine is employed to classify profile segments as members of pre-defined classes (such as asphalt, brick, gravel, etc.). The classification algorithm is validated with experimental data collected with a passenger vehicle driving in real-world conditions. The algorithm is shown to classify multiple terrain types with reasonable accuracy at a range of typical automotive speeds. It is also shown that the removal of terrain impulses prior to classification improves classifier performance.  相似文献   
89.
This contribution furthers the control framework for driver assistance systems in Part I to cooperative systems, where equipped vehicles can exchange relevant information via vehicle-to-vehicle communication to improve the awareness of the ambient situation (cooperative sensing) and to manoeuvre together under a common goal (cooperative control). To operationalize the cooperative sensing strategy, the framework is applied to the development of a multi-anticipative controller, where an equipped vehicle uses information from its direct predecessor to predict the behaviour of its pre-predecessor. To operationalize the cooperative control strategy, we design cooperative controllers for sequential equipped vehicles in a platoon, where they collaborate to optimise a joint objective. The cooperative control strategy is not restricted to cooperation between equipped vehicles. When followed by a human-driven vehicle, equipped vehicles can still exhibit cooperative behaviour by predicting the behaviour of the human-driven follower, even if the prediction is not perfect.The performance of the proposed controllers are assessed by simulating a platoon of 11 vehicles with reference to the non-cooperative controller proposed in Part I. Evaluations show that the multi-anticipative controller generates smoother behaviour in accelerating phase. By a careful choice of the running cost specification, cooperative controllers lead to smoother decelerating behaviour and more responsive and agile accelerating behaviour compared to the non-cooperative controller. The dynamic characteristics of the proposed controllers provide new insights into the potential impact of cooperative systems on traffic flow operations, particularly at the congestion head and tail.  相似文献   
90.
GLENN LYONS 《运输评论》2013,33(4):485-509
In 1963, the Buchanan Report in the UK advocated a combination of new road capacity, improved public transport and traffic restraint as a means to tackle congestion. Forty years on, and the advice from many transport experts remains the same. However, the scale and complexity of the problems associated with a mobility‐dependent society have grown. The need for politicians to make tough but realistic policy decisions on transport is now becoming unavoidable. They must confront the realities of living with the car as must the general public. Policymakers now also have social well‐being and sustainable development moving higher on their agendas alongside transport. Against such a backdrop, the paper makes the case for transport research, policy and practice to acknowledge more fully the inherent links between transport and society. It argues that greater recognition and understanding of such links is crucial to confronting the present realities. Transport does not merely serve society: it shapes society, as in turn society shapes transport. The future of each is dependent on the other, and this fact must be recognized. The paper advocates in turn that the transport profession must move from its heartlands in engineering and economics also to embrace more fully such disciplines as sociology and psychology. A factual picture of the many facets of present‐day society is presented and the implications for travel demand are discussed. Through considering phenomena such as social norms and habitual behaviour, it is then argued that the travel choices and behaviour of individuals are not simply a matter of economic optimization. This points to the need for decision‐makers to be furnished with better evidence about the transport problems faced and the potential efficacy of measures that might be taken. Discussion of public attitudes and the role of the media are included in the context of assessing how politicians can be encouraged and supported in their implementation of realistic but unpopular policies. Evidence and experience within the paper are UK based, although many of the issues and arguments apply world wide.  相似文献   
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