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Coupling a traffic microsimulation with an emission model is a means of assessing fuel consumptions and pollutant emissions at the urban scale. Dealing with congested states requires the efficient capture of traffic dynamics and their conditioning for the emission model. Two emission models are investigated here: COPERT IV and PHEM v11. Emission calculations were performed at road segments over 6 min periods for an area of Paris covering 3 km2. The resulting network fuel consumption (FC) and nitrogen oxide (NOx) emissions are then compared. This article investigates: (i) the sensitivity of COPERT to the mean speed definition, and (ii) how COPERT emission functions can be adapted to cope with vehicle dynamics related to congestion. In addition, emissions are evaluated using detailed traffic output (vehicle trajectories) paired with the instantaneous emission model, PHEM.COPERT emissions are very sensitive to mean speed definition. Using a degraded speed definition leads to an underestimation ranging from −13% to −25% for fuel consumption during congested periods (from −17% to −36% respectively for NOx emissions). Including speed distribution with COPERT leads to higher emissions, especially under congested conditions (+13% for FC and +16% for NOx). Finally, both these implementations are compared to the instantaneous modeling chain results. Performance indicators are introduced to quantify the sensitivity of the coupling to traffic dynamics. Using speed distributions, performance indicators are more or less doubled compared to traditional implementation, but remain lower than when relying on trajectories paired with the PHEM emission model. 相似文献
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金学宁 《南通航运职业技术学院学报》2006,5(2):21-23
文章通过对亚里士多德在《尼各马科伦理学》中的技术以及人的德性等伦理学思想进行评析,联系现代社会技术发展中存在的一些技术伦理问题的反思,提出以亚里士多德的“中道”思想,对技术进行理性的思考、选择,提出技术在实践中接受伦理的规范,寻求社会的普遍性,实现技术价值,最终达到“至善”,获得幸福。 相似文献
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对轮胎侧偏刚度进行估算能满足研发汽车稳定性控制系统的需要,文章探讨了3种在线估算轮胎侧偏刚度的方法,并进行了比较分析。结果表明,直接法和GPS/INS综合测量法原理清晰且求解高效,但这2种方法仅仅适用于轮胎线性范围内;加速度变化率法适应性好,但需要冲动传感器或通过信号高性能滤波,故成本较高。 相似文献
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该文系统地介绍了在天安门广场夜景照明工程中,从基于创新设计理念出发,针对存在的相关问题,如何进行城市广场的总体设计和广场、道路、建筑前铺装的照明改建,对围合成广场的建(构)筑物照明的改建,以及广场上建(构)筑物前绿地、树木、行道树的照明改建的实施情况及相关思考,以期为同业提供可借鉴的资料和经验。 相似文献
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方形波导的图像传输特性 总被引:1,自引:0,他引:1
对方形波导的图像传输问题进行了理论分析与探讨,推导出其自成像周期,并借助于数值方法模拟其图像传输特性.结果表明:二分之一自成像周期截面具有成反像的特性;四分之一自成像周期截面可成四个自成像,其他位置的图像与输入位置的图像依次关于y轴、原点和x轴对称. 相似文献
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在道路改建中,曲线设计法是最大限度利用原有路基的有效方法.采用多项式拟合曲线对公路工程线形设计实例进行设计研究,并将设计计算结果与三次样条函数设计法进行比较.研究表明,基于最小二乘法原理的多项式曲线拟合法与三次样条函数设计法的计算结果接近,同样能满足路线设计规范的要求,且计算过程更为简便,值得在设计工作中参考和应用. 相似文献