Under the background of high-speed rail networking, this paper uses the passenger trains, the type and direction of the railway via Hang Yong and its extension road line, to construct adsorption and dependency index a...Under the background of high-speed rail networking, this paper uses the passenger trains, the type and direction of the railway via Hang Yong and its extension road line, to construct adsorption and dependency index among cities, depict the contact pattern between the Hang Yong dual-core and its hinterland, measure the “net effect” that two center cities (Hangzhou, Ningbo) have on their hinterland, and estimate population agglomeration potential and future possible population flows of Zhejiang Province and the main sample cities. The result shows that, compared with Ningbo, Hangzhou has stronger radiation force to the vast majority of sample cities, and the sample cities affected more by Ningbo mainly concentrates in Ningbo-Taizhou-Wenzhou along;in addition, the sample cities such as Hangzhou, Ningbo and so on show better population agglomeration, then the population “scramble” phenomenon between cities has begun to appear.展开更多
In this paper,multi_quadric equations interpolation is used to establish a widely covered and valuable speed field model,with which the crustal movement image is obtained.
This paper proposes the new speed control method of electric vehicles by generating the longitudinal speed pattern for improving the ride comfort against the longitudinal acceleration/deceleration. Since the longitudi...This paper proposes the new speed control method of electric vehicles by generating the longitudinal speed pattern for improving the ride comfort against the longitudinal acceleration/deceleration. Since the longitudinal acceleration/deceleration of EVs causes the discomfort of passengers, reducing such bad effect of acceleration/deceleration acting on passengers is very important for not only the ride comfort of passengers but also vehicle running safety. The proposed method is applying the general optimal control theory and it generates the speed pattern for improving the passenger ride quality based on evaluating the variations of acceleration and the jerk which is time derivative of the acceleration. The effectiveness of the present method is demonstrated through numerical experiments compared with some conventional methods.展开更多
Taking Beijing–Shanghai High-speed Railway(the section of Zhenjiangnan Station) for example,this paper applied UAV remote sensing data and GIS spatial analysis to analyze current land use types in this section,on thi...Taking Beijing–Shanghai High-speed Railway(the section of Zhenjiangnan Station) for example,this paper applied UAV remote sensing data and GIS spatial analysis to analyze current land use types in this section,on this basis used landscape pattern indices that showed high correlation with land use changes for the quantitative analysis and evaluation of ecosystem structure in the study area and also landscape pattern after the construction of high-speed railway.The results showed that UAV images performed well in the evaluation of railway landscape ecological environment,landscape structure and features represented by the selected landscape pattern indices in this paper were applicable,and capable of ensuring scientific evaluation of ecological environmental impact;the overall landscape pattern of the Zhenjiangnan Station section(Beijing–Shanghai High-speed Railway) after completion was moderate,and local ecosystem was damaged,thus scientific and reasonable ecological planning was required to design and change landscape structure.展开更多
The effects of quenching temperature, cooling pattern, temper temperature andtemper times on the structure and properti-es of high speed steel (HSS) rolls have beeninvestigated. The results show that, when the quenchi...The effects of quenching temperature, cooling pattern, temper temperature andtemper times on the structure and properti-es of high speed steel (HSS) rolls have beeninvestigated. The results show that, when the quenching temperature is lower than 1050℃ thehardness of HSS increases with the quenching temperature increasing in oil cooling, but when thequenching temperature exceeds 1100℃ the hardness decreases. In the conditions of salt bath coolingand air cooling, the effect of quenching temperature on the hardness is similar to the above law,but the quenching temperature obtaining the highest hardness is higher than that in oil cooling.When the temper temperature below 350℃ the hardness of HSS has a little change, when above 475℃the hardness will increase with the temper temperature increasing, and the highest hardness isobtained at 525℃. When the temper temperature continues to increase, the hardness decreases. Twicetemper has little effect on the hardness, but three times temper decreases the hardness. HSS in aircooling has lower hardenability, oil cooling can easily produce crackle, and HSS quenching in saltbath has high harde-nability and excellent wear resistance.展开更多
准确识别车辆当前驾驶行为模式是自动驾驶领域亟待解决的技术问题。为实现驾驶行为模式精准解析,提高模型识别精度和可靠性,通过开展自然驾驶试验,采集高速工况下20名驾驶人的驾驶行为数据及视觉特性数据等多源参数信息,分析4类典型驾...准确识别车辆当前驾驶行为模式是自动驾驶领域亟待解决的技术问题。为实现驾驶行为模式精准解析,提高模型识别精度和可靠性,通过开展自然驾驶试验,采集高速工况下20名驾驶人的驾驶行为数据及视觉特性数据等多源参数信息,分析4类典型驾驶行为模式(自由行驶、跟车、左换道、右换道)运行规律及多源参数耦合特性。基于主成分分析法确定4类驾驶行为模式表征指标集,使用支持向量机、随机森林决策树算法建立驾驶行为模式识别模型,通过学习训练,分析比较模型识别结果,对识别效果较好的模型进一步优化,分析优化模型对4类驾驶行为模式识别精度的时序性变化特征。研究结果表明:支持向量机模型、随机森林决策树模型、基于多层感知器神经网络的随机森林优化模型总体识别精度分别为89.4%、90.5%、91.9%;4类驾驶行为模式的AUC(area under the curve)值均高于0.93,可较好地识别车辆当前驾驶行为模式。此外,随机森林优化模型对4类驾驶行为模式的识别精度均随时间推移,呈现先增长后趋于稳定的变化态势,且同一时刻的自由行驶及跟车模式识别精度高于向左及向右换道模式。研究结果可为高级别自动驾驶系统决策及控制策略的制定提供理论基础和技术支持。展开更多
文摘Under the background of high-speed rail networking, this paper uses the passenger trains, the type and direction of the railway via Hang Yong and its extension road line, to construct adsorption and dependency index among cities, depict the contact pattern between the Hang Yong dual-core and its hinterland, measure the “net effect” that two center cities (Hangzhou, Ningbo) have on their hinterland, and estimate population agglomeration potential and future possible population flows of Zhejiang Province and the main sample cities. The result shows that, compared with Ningbo, Hangzhou has stronger radiation force to the vast majority of sample cities, and the sample cities affected more by Ningbo mainly concentrates in Ningbo-Taizhou-Wenzhou along;in addition, the sample cities such as Hangzhou, Ningbo and so on show better population agglomeration, then the population “scramble” phenomenon between cities has begun to appear.
文摘In this paper,multi_quadric equations interpolation is used to establish a widely covered and valuable speed field model,with which the crustal movement image is obtained.
文摘This paper proposes the new speed control method of electric vehicles by generating the longitudinal speed pattern for improving the ride comfort against the longitudinal acceleration/deceleration. Since the longitudinal acceleration/deceleration of EVs causes the discomfort of passengers, reducing such bad effect of acceleration/deceleration acting on passengers is very important for not only the ride comfort of passengers but also vehicle running safety. The proposed method is applying the general optimal control theory and it generates the speed pattern for improving the passenger ride quality based on evaluating the variations of acceleration and the jerk which is time derivative of the acceleration. The effectiveness of the present method is demonstrated through numerical experiments compared with some conventional methods.
基金Sponsored by Environmental Protection Fund of China-"123 Project"of Liaoning Environmental Scientific Research&Education(CEPF2010-123-2-10)
文摘Taking Beijing–Shanghai High-speed Railway(the section of Zhenjiangnan Station) for example,this paper applied UAV remote sensing data and GIS spatial analysis to analyze current land use types in this section,on this basis used landscape pattern indices that showed high correlation with land use changes for the quantitative analysis and evaluation of ecosystem structure in the study area and also landscape pattern after the construction of high-speed railway.The results showed that UAV images performed well in the evaluation of railway landscape ecological environment,landscape structure and features represented by the selected landscape pattern indices in this paper were applicable,and capable of ensuring scientific evaluation of ecological environmental impact;the overall landscape pattern of the Zhenjiangnan Station section(Beijing–Shanghai High-speed Railway) after completion was moderate,and local ecosystem was damaged,thus scientific and reasonable ecological planning was required to design and change landscape structure.
文摘The effects of quenching temperature, cooling pattern, temper temperature andtemper times on the structure and properti-es of high speed steel (HSS) rolls have beeninvestigated. The results show that, when the quenching temperature is lower than 1050℃ thehardness of HSS increases with the quenching temperature increasing in oil cooling, but when thequenching temperature exceeds 1100℃ the hardness decreases. In the conditions of salt bath coolingand air cooling, the effect of quenching temperature on the hardness is similar to the above law,but the quenching temperature obtaining the highest hardness is higher than that in oil cooling.When the temper temperature below 350℃ the hardness of HSS has a little change, when above 475℃the hardness will increase with the temper temperature increasing, and the highest hardness isobtained at 525℃. When the temper temperature continues to increase, the hardness decreases. Twicetemper has little effect on the hardness, but three times temper decreases the hardness. HSS in aircooling has lower hardenability, oil cooling can easily produce crackle, and HSS quenching in saltbath has high harde-nability and excellent wear resistance.
文摘准确识别车辆当前驾驶行为模式是自动驾驶领域亟待解决的技术问题。为实现驾驶行为模式精准解析,提高模型识别精度和可靠性,通过开展自然驾驶试验,采集高速工况下20名驾驶人的驾驶行为数据及视觉特性数据等多源参数信息,分析4类典型驾驶行为模式(自由行驶、跟车、左换道、右换道)运行规律及多源参数耦合特性。基于主成分分析法确定4类驾驶行为模式表征指标集,使用支持向量机、随机森林决策树算法建立驾驶行为模式识别模型,通过学习训练,分析比较模型识别结果,对识别效果较好的模型进一步优化,分析优化模型对4类驾驶行为模式识别精度的时序性变化特征。研究结果表明:支持向量机模型、随机森林决策树模型、基于多层感知器神经网络的随机森林优化模型总体识别精度分别为89.4%、90.5%、91.9%;4类驾驶行为模式的AUC(area under the curve)值均高于0.93,可较好地识别车辆当前驾驶行为模式。此外,随机森林优化模型对4类驾驶行为模式的识别精度均随时间推移,呈现先增长后趋于稳定的变化态势,且同一时刻的自由行驶及跟车模式识别精度高于向左及向右换道模式。研究结果可为高级别自动驾驶系统决策及控制策略的制定提供理论基础和技术支持。
