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101.
为了解决纯电动汽车动力性和操控性难以同时兼顾的问题,将驾驶员意图分为稳态意图和动态意图,稳态意图用于保证车辆的操控性,动态意图用于保证车辆的动力性,在此基础上提出了一种基于驾驶员意图识别的纯电动汽车动力性驱动控制策略,该策略首先分别采用“典型工作点+分段插值”和模糊推理方法来识别驾驶员的稳态和动态意图;接着采用“动态补偿转矩保持”和“动态补偿转矩归零”等算法计算动态补偿转矩;最后通过“增量式”动态补偿转矩跟踪算法和电机过载管理算法给出最终的转矩指令。仿真与试验结果表明,该策略既可以根据驾驶员稳态意图保证车辆的操控性,也可根据驾驶员动态意图提高车辆的动力性。  相似文献   
102.
对战场上出现的大量目标隐含的战术意图的正确、快速、自动识别,能大大提高战场指挥人员的决策效率。以战场态势估计为基础,提出战术意图识别的框架模型;结合最大近似法、D—S证据理论用于战术意图序贯识别的不同阶段。该研究属于决策级数据融合的范畴。  相似文献   
103.
张秀峰 《铁道学报》2005,27(6):43-49
基于有源滤波器的同相供电系统的关键技术是对补偿电流的实时检测,检测的精度高低和动态响应性能好坏会影响三相平衡效果和谐波与无功的补偿效果。本文针对以往检测方法存在动态响应速度慢的缺点,提出了2种补偿电流检测方法:有功电流分离检测法和无延时虚拟三相检测法。分析与仿真证实,无论被检测电压与电流有无畸变,2种检测方法都可根据同相供电平衡补偿的不同要求(仅平衡三相、平衡三相滤除谐波和平衡三相滤除谐波并补偿无功)完成补偿电流检测,且检测精度高、动态响应速度快。  相似文献   
104.
在矩形箱格的矩形沉箱和扇形箱格之圆形沉箱的浮游稳定计算原理的基础上,对二种类型椭圆沉箱两端半圆段内不同几何形状的箱格之自身对称轴的惯性矩,经图形转轴公式和平行移动公式转换,并经数学推导得到对椭圆形沉箱纵向形心轴平行的箱格自身形心轴的惯性矩i及其之和Σi的计算式,从而解决了椭圆形沉箱浮游稳定计算的问题。  相似文献   
105.
分析船舶由海水进入淡水港或航道时吃水增加问题,指出随船型、尺度、排水量越来越大等因素影响导致船舶纵倾变化已不可忽视,并提出了预防造成严重后果的对策。  相似文献   
106.
107.
通过大骨节病和克山病共存地区360名小学生手部 X 线、心电图和发、尿硒分析,结果,干骺端病变检出率为16.16%,X 线异常率为37.22%,心电图异常率为13.06%,大骨节病阳性体征和(或)X 线异常总检出率为56.11%;异常心电图与异常 X 线、阳性体征和(或)X 线征符合率分别为53.19%和72%.心电图和 X线2项检出率呈显著正相关关系;心电图、干骺端病变检出率与发、尿硒呈负相关关系.本文结果结合文献报道低硒地区有单独大骨节病、克山病存在的事实,提示病区不同人体硒水平可造成发、尿硒含量与心电图、干骺端病变检出率间有相关关系,也使心电图与 X 线2项检出率间有相关关系。不能单从两病共存地区心电图、干骺端病变、发尿硒间这种相关关系及心电图和 X 线有较高符合率,说低硒是大骨节病、克山病的共同病因,也不能说大骨节病和克山病是同病异症。  相似文献   
108.
Cities in developing countries like India are facing some of the same concerns that North American cities are: congestion and urban growth. However, there is a sense of urgency in cities like Delhi, India in that this growth is far more rapid as both urbanization and motorization are ongoing processes that have not yet peaked. In this paper, we examine land use change and its relationship with transportation infrastructure and other planning related variables in a spatial context. We estimate land use change models at two different scales from separate data. Cellular automation and Markov models were used to understand change at the regional scale and discrete choice models to predict change at the local level. The results suggest that land use in the Delhi metropolitan area is rapidly intensifying while losing variety. These changes are affected by industrial, commercial and infrastructure location and planners and policy-makers need to better understand the implications of location decisions. We also examine these results in the context of a policy framework for data-based planning that links land use and transportation models for Delhi.  相似文献   
109.
Climatic changes in the Northern Hemisphere have led to remarkable environmental changes in the Arctic Ocean, which is surrounded by permafrost. These changes include significant shrinking of sea-ice cover in summer, increased time between sea-ice break-up and freeze-up, and Arctic surface water freshening and warming associated with melting sea-ice, thawing permafrost, and increased runoff. These changes are commonly attributed to the greenhouse effect resulting from increased atmospheric carbon dioxide (CO2) concentration and other non-CO2 radiatively active gases (methane, nitrous oxide). The greenhouse effect should be most pronounced in the Arctic where the largest air CO2 concentrations and winter–summer variations in the world for a clean background environment were detected. However, the air–land–shelf interaction in the Arctic has a substantial impact on the composition of the overlying atmosphere; as the permafrost thaws, a significant amount of old terrestrial carbon becomes available for biogeochemical cycling and oxidation to CO2. The Arctic Ocean's role in determining regional CO2 balance has been ignored, because of its small size (only  4% of the world ocean area) and because its continuous sea-ice cover is considered to impede gaseous exchange with the atmosphere so efficiently that no global climate models include CO2 exchange over sea-ice. In this paper we show that: (1) the Arctic shelf seas (the Laptev and East-Siberian seas) may become a strong source of atmospheric CO2 because of oxidation of bio-available eroded terrestrial carbon and river transport; (2) the Chukchi Sea shelf exhibits the strong uptake of atmospheric CO2; (3) the sea-ice melt ponds and open brine channels form an important spring/summer air CO2 sink that also must be included in any Arctic regional CO2 budget. Both the direction and amount of CO2 transfer between air and sea during open water season may be different from transfer during freezing and thawing, or during winter when CO2 accumulates beneath Arctic sea-ice; (4) direct measurements beneath the sea ice gave two initial results. First, a drastic pCO2 decrease from 410 μatm to 288 μatm, which was recorded in February–March beneath the fast ice near Barrow using the SAMI-CO2 sensor, may reflect increased photosynthetic activity beneath sea-ice just after polar sunrise. Second, new measurements made in summer 2005 beneath the sea ice in the Central Basin show relatively high values of pCO2 ranging between 425 μatm and 475 μatm, values, which are larger than the mean atmospheric value in the Arctic in summertime. The sources of those high values are supposed to be: high rates of bacterial respiration, import of the Upper Halocline Water (UHW) from the Chukchi Sea (CS) where values of pCO2 range between 400 and 600 μatm, a contribution from the Lena river plume, or any combination of these sources.  相似文献   
110.
以往动态车道研究倾向于在固定信号配时或预先设定的信号配时方案下进行优化,无法充分利用交叉口的时空资源.本文根据实时交通需求,以交叉口车辆平均延误最小为目标,以信号周期、相位绿灯时间和车道数为约束条件,构建动态车道与交通信号协同优化模型.模型分两部分,第1部分考虑进出口道车道平衡,计算可行的动态车道备选方案,将备选方案的输出参数作为第2部分模型的输入参数;第2部分根据实时交通需求,生成动态车道优化方案和信号优化方案.将本文优化方法与传统信号配时方法进行比较,实验结果表明,本文模型能更好地降低交叉口平均延误,有效提升信号交叉口时空资源利用率.  相似文献   
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