车路协同系统(IVICS)是保障安全高效出行的新兴技术之一,将高精度车辆轨迹数据与机器学习方法相结合,提出一种可应用于IVICS的多车道交织区的潜在风险判别与冲突预测方法。首先,基于无人机视频,从广域视角提取交织区交通矢量位置、速度...车路协同系统(IVICS)是保障安全高效出行的新兴技术之一,将高精度车辆轨迹数据与机器学习方法相结合,提出一种可应用于IVICS的多车道交织区的潜在风险判别与冲突预测方法。首先,基于无人机视频,从广域视角提取交织区交通矢量位置、速度等信息,并划分上下游、交织影响区等多个分区;然后,考虑决策行为(车车边缘距离、接近率)与车辆行为(横纵向速度、加速度、速度角度)构建风险判别模型,以单位面积冲突次数、持续时间、冲突密度等指标评估风险;最后,基于朴素贝叶斯模型与logistic回归模型分别进行交通冲突预测,与实测数据相比,预测准确率分别为74.86%、87.10%,Area Under Curve分别为0.84、0.88,表明logistic回归模型具有更好的预测性能。研究成果有助于交管部门制定与优化交通管控方案,可应用于IVICS动态预警。展开更多
Danba （丹巴） domal metamorphic terrain belongs to Songpan （松潘）-Ganze （甘孜） orogenic belt, where typical Barrovian and Buchan metamorphic zones are preserved. The former included chlorite, biotite, garnet, sta...Danba （丹巴） domal metamorphic terrain belongs to Songpan （松潘）-Ganze （甘孜） orogenic belt, where typical Barrovian and Buchan metamorphic zones are preserved. The former included chlorite, biotite, garnet, staurolite, kyanite and sillimanite zones, while the latter only developed silimanite＋muscovite and sillimanite＋K-feldspar zones. Integrated study has been carried on metamorphic reactions of garnet production and consumption, P-T paths and P-T-X-M phase relation and thermal tectonic model for Danba metamorphic zones. Petrological textures in thin sections show that garnet production and consumption in kyanite-sillimanite zone is mainly attributed to ChI＋Ms＋PI＋Q= Grt＋Bt＋H20 and kyanite=sillimanite respectively. Based on mineral compositions, the geothermo- barometry gives an average P, T condition of （4.9±0.3）×10^8 Pa, 543±30 ℃ for the first growth stage of the garnet and （5.8±0.3）×10^8 Pa, 534±29 ℃ for the second stage of garnet growth respectively. Anti-counter clockwise P-T paths were drawn using Gibbs method by NCMnKFMASH system for sample G98686 in the kyanite zone. The P-T-X-M modeling for the first mineral assemblages shows that the prediction is similar to the measured values in gossular, almandine and spessartine but mole fraction of pyrope and Fe/（Fe＋Mg） deviated far from the contours; while that for the second mineral assemblages exhibits that the prediction is consistent with the measured value of pyrope, grossular content and Fe/（Fe＋Mg） of garnet. A thermal tectonic model that there are at least three structure levels across the thrust-decollement zones is presented according to the P-T paths, metamorphic grades and deformation styles for the staurolite-kyanite zone of the Barrovian type metamorphism, which will provide some constraints for the evolution of the nappe complex.展开更多
A coupled system simulating both firebox and reactor is established to study the naphtha pyrolysis in an industrial tubular furnace.The firebox model is based on zone method including combustion,radiation,and convecti...A coupled system simulating both firebox and reactor is established to study the naphtha pyrolysis in an industrial tubular furnace.The firebox model is based on zone method including combustion,radiation,and convection to simulate heat transfer in the furnace.A two-dimensional recirculation model is proposed to estimate the flow field in furnace.The reactor model integrates the feedstock reconstruction model,an auto-generator of detail kinetic schemes,and the reactor simulation model to simulate the reaction process in the tubular coil.The coupled simulation result is compared with industrial process and shows agreement within short computation time.展开更多
文摘车路协同系统(IVICS)是保障安全高效出行的新兴技术之一,将高精度车辆轨迹数据与机器学习方法相结合,提出一种可应用于IVICS的多车道交织区的潜在风险判别与冲突预测方法。首先,基于无人机视频,从广域视角提取交织区交通矢量位置、速度等信息,并划分上下游、交织影响区等多个分区;然后,考虑决策行为(车车边缘距离、接近率)与车辆行为(横纵向速度、加速度、速度角度)构建风险判别模型,以单位面积冲突次数、持续时间、冲突密度等指标评估风险;最后,基于朴素贝叶斯模型与logistic回归模型分别进行交通冲突预测,与实测数据相比,预测准确率分别为74.86%、87.10%,Area Under Curve分别为0.84、0.88,表明logistic回归模型具有更好的预测性能。研究成果有助于交管部门制定与优化交通管控方案,可应用于IVICS动态预警。
基金supported by the National Natural Science Foundation of China (Nos. 40472097, 90814006)Re-search Fund for the Doctoral Program of Higher Education of China (No. 20070491516)
文摘Danba （丹巴） domal metamorphic terrain belongs to Songpan （松潘）-Ganze （甘孜） orogenic belt, where typical Barrovian and Buchan metamorphic zones are preserved. The former included chlorite, biotite, garnet, staurolite, kyanite and sillimanite zones, while the latter only developed silimanite＋muscovite and sillimanite＋K-feldspar zones. Integrated study has been carried on metamorphic reactions of garnet production and consumption, P-T paths and P-T-X-M phase relation and thermal tectonic model for Danba metamorphic zones. Petrological textures in thin sections show that garnet production and consumption in kyanite-sillimanite zone is mainly attributed to ChI＋Ms＋PI＋Q= Grt＋Bt＋H20 and kyanite=sillimanite respectively. Based on mineral compositions, the geothermo- barometry gives an average P, T condition of （4.9±0.3）×10^8 Pa, 543±30 ℃ for the first growth stage of the garnet and （5.8±0.3）×10^8 Pa, 534±29 ℃ for the second stage of garnet growth respectively. Anti-counter clockwise P-T paths were drawn using Gibbs method by NCMnKFMASH system for sample G98686 in the kyanite zone. The P-T-X-M modeling for the first mineral assemblages shows that the prediction is similar to the measured values in gossular, almandine and spessartine but mole fraction of pyrope and Fe/（Fe＋Mg） deviated far from the contours; while that for the second mineral assemblages exhibits that the prediction is consistent with the measured value of pyrope, grossular content and Fe/（Fe＋Mg） of garnet. A thermal tectonic model that there are at least three structure levels across the thrust-decollement zones is presented according to the P-T paths, metamorphic grades and deformation styles for the staurolite-kyanite zone of the Barrovian type metamorphism, which will provide some constraints for the evolution of the nappe complex.
基金Supported by the National Natural Science Foundation of China(U1462206)
文摘A coupled system simulating both firebox and reactor is established to study the naphtha pyrolysis in an industrial tubular furnace.The firebox model is based on zone method including combustion,radiation,and convection to simulate heat transfer in the furnace.A two-dimensional recirculation model is proposed to estimate the flow field in furnace.The reactor model integrates the feedstock reconstruction model,an auto-generator of detail kinetic schemes,and the reactor simulation model to simulate the reaction process in the tubular coil.The coupled simulation result is compared with industrial process and shows agreement within short computation time.
