共查询到19条相似文献,搜索用时 93 毫秒
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《工业技术创新》2015,(1)
为有效解决弹光调制(Photoelastic Modulation)傅里叶变换光谱仪数据量大,调制干涉信号频率高,所需采集速度高的问题,提出了一种基于FPGA和模数转换器件AD9224相结合的高速数据采集方案。该方案在分析AD数据采集工作模式的基础上,在Xilinx ISE 12.4的开发环境中,利用Verilog硬件描述语言编程,对数据的高速采集进行了设计输入和仿真验证,实现了AD9224在FPGA控制下的高速信号采集,采集速度为40M,通过设计采集存储控制板实现了硬件测试,验证了该设计的可行性和准确性,实现了弹光调制傅里叶变换光谱仪高速数据采集,数据的快速传输与上位机显示。 相似文献
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田径场位于奥林匹克体育中心,占地五万多平方米,建筑面积30653平方米,东西看台和绕场一周的环形高架平台可容纳两万名观众。由北京市建筑设计院设计,北京第三城市建设工程公司施工,该工程于1989年12月16日竣工。环形高架平台上层是观众出入场疏散通道,下层是各种车辆的通道。看台和高架平台均必须做防水处理,保证不渗漏。原设计准备做胶乳沥清防水,但在数量达25000多平方米的看台、高架平台上做涂 相似文献
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总平面管理——顺利运转的效率开关水平运输.为保证运输通畅,场内道路布置最好为环形,并与场外城市道路相结合,尽量多开大门,提高运输效率.根据基坑施工、主体施工、装修施工不同时期需要,对道路布置进行动态调整.加强车辆交通调度与道路维护管理,保证整个施工期间道路交通的畅通. 相似文献
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为了解决道路两相位交叉口所存在的左转车辆抢行问题,避免造成严重交通冲突,首先分析了左转车辆抢行行为、路径抢行、以及与直行车辆到达冲突点的时间差相关的概率抢行,在考虑过街行人对抢行行为干扰的情况下,构建了车辆、行人耦合的双路径左转-直行冲突元胞自动机模型,通过计算机仿真分析研究了左转车辆抢行行为对交叉口通行能力的影响。结果表明,无过街行人时,左转车辆抢行使交叉口通行能力下降约5%;有过街行人干扰时,交叉口的通行能力则进一步降低10%~25%。研究结果可为提高道路交叉口服务水平、提高道路通行率和安全性决策提供参考。 相似文献
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侯郁 《石油工业技术监督》2005,21(10):43-46
对国内外汽车可靠性调查和用户满意指数测评进行分析,提出对石油石化行业产品质量可靠性调查评价的建议,指出,质量可靠性的调查测评方法越简单,越容易实行。 相似文献
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《Telecommunications Policy》2023,47(7):102595
The emergence of new wireless technologies, such as the Internet of Things, allows digitalizing new and diverse urban activities. Thus, wireless traffic grows in volume and complexity, making prediction, investment planning, and regulation increasingly difficult. This article characterizes urban wireless traffic evolution, supporting operators to drive mobile network evolution and policymakers to increase national and local competitiveness. We propose a holistic method that widens previous research scope, including new devices and the effect of policy from multiple government levels. We provide an analytical formulation that combines existing complementary methods on traffic evolution research and diverse data sources. Results for a centric area of Helsinki during 2020–2030 indicate that daily volumes increase, albeit a surprisingly large part of the traffic continues to be generated by smartphones. Machine traffic gains importance, driven by surveillance video cameras and connected cars. While camera traffic is sensitive to law enforcement policies and data regulation, car traffic is less affected by transport electrification policy. High-priority traffic remains small, even under encouraging autonomous vehicle policies. Based on peak hour results, we suggest that 5G small cells might be needed around 2025, albeit the utilization of novel radio technology and additional mid-band spectrum could delay this need until 2029. We argue that mobile network operators inevitably need to cooperate in constructing a single, shared small cell network to mitigate the high deployment costs of massively deploying small cells. We also provide guidance to local and national policymakers for IoT-enabled competitive gains via the mitigation of five bottlenecks. For example, local monopolies for mmWave connectivity should be facilitated on space-limited urban furniture or risk an eventual capacity crunch, slowing down digitalization. 相似文献
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车用纺织品材料应用现状与发展趋势的研究 总被引:1,自引:1,他引:0
在汽车行业日益激烈的竞争环境下,丰富多彩的汽车内饰,正影响着人们对车辆的选择。本文在公司实地考察的基础上,通过查阅大量文献,对汽车内饰纺织品用材料进行了系统地研究,主要就其应用现状和发展趋势作了具体的阐述。 相似文献
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Ambarish Chandra Sumeet Gulati James M. Sallee 《The Journal of industrial economics》2017,65(2):235-274
We establish that there are large and persistent differences in final transaction prices for identical new cars, and that demographic characteristics explain at least 20% of the observed variation. Older consumers perform progressively worse in negotiations, and the age premium is greater for women than for men. Our results suggest that the complex nature of vehicle transactions leads to price dispersion in this market, and that the worst performing groups—older women—have the lowest rates of market participation. We conjecture that the results are driven by the sharp increases in women's education and labor force participation in recent decades. 相似文献
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We analyze the evolution of CO2 emissions of new vehicles sold in France between 2003 and 2008. We investigate in particular the effect of two policies introduced during that time: the energy label requirement, which went into effect in the end of 2005, and a feebate based on CO2 emissions of new vehicles in 2008. We estimate a flexible model of demand for automobiles that incorporates consumers’ heterogeneity and valuation of vehicle CO2 emissions. Our results show that there has been a shift in preferences towards low-emitting cars. Moreover, the timing of these changes is consistent with the introduction of the two policies. This suggests that the feebate had a crowding-in effect in addition to its price effect. Overall, the change in preferences accounts for 40% of the overall decrease in average CO2 emissions of new cars in the period. 相似文献
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Ohjin Kwon Anthony J. Dukes S. Siddarth Jorge M. Silva‐Risso 《The Journal of industrial economics》2015,63(4):736-762
This research theorizes that sellers of durable goods can utilize inferences about the buyer's willingness to pay based not only on her decision to trade in the old good but also on its characteristics. We find empirical support for this theory using transaction data for new car purchases. The results support the notion that dealers infer a higher willingness to pay and charge higher prices to consumers who trade in a used vehicle than to those who do not. We also find that dealers charge even higher prices to those consumers who trade in used cars that are similar to the new one. 相似文献
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Ökonomische Analyse der Erstnutzer von Elektrofahrzeugen 总被引:1,自引:1,他引:0
Plug-in hybrids and purely electric vehicles are currently being intensively discussed. The economic efficiency of these vehicles is essential for their future market success. As economic analyses of the specific driving profiles of customer groups in Germany have shown, economic efficiency depends on factors such as vehicle mileage, the share of urban driving and the share of electrical driving. For the first users of electric mobility, small, purely electrically-operated town cars will be offered in 2015. About 4 % of German car drivers were found to be suitable for such a car. Later on, plug-in hybrids will also become attractive for certain consumer groups, in particular for full-time workers from communities with fewer than 100,000 residents. Less suited are car drivers in large cities as they do not usually drive sufficient distances for an electric car to pay off, often do not have access to their own private parking and the majority only own one vehicle. Housewives/househusbands and pensioners comprise other groups not considered to be suitable as the first users of electric vehicles from a purely economic perspective. 相似文献