随着近2年慕课(massive open online course,MOOC)的兴起,教育大数据分析正成为一个新兴的研究方向.2013年秋,北京大学在Coursera上开设了6门慕课.通过分析挖掘约8万多人次参与这6门课的海量学习行为数据,力图展现慕课学习活动多个侧面...随着近2年慕课(massive open online course,MOOC)的兴起,教育大数据分析正成为一个新兴的研究方向.2013年秋,北京大学在Coursera上开设了6门慕课.通过分析挖掘约8万多人次参与这6门课的海量学习行为数据,力图展现慕课学习活动多个侧面的风貌.同时,首次针对中文慕课中学习行为的特点,将学习者分类,以更加深入地考察学习行为与学习效果之间的关系.在此基础上,通过选择学习者的若干典型行为特征,对他们最后的学习成果进行预测的工作也尚属首次.数据表明:基于学习行为的特征分析能有效地判别一个学习者能否成功完成学习任务获得通过证书,并能找出潜在的认真学习者,这为今后更加精准的慕课教学测评提供了一种依据.展开更多
The structural styles can be used to analyses and predict developments and distributions of sand bodies in a rift basin. The dynamic process of faulting and sedimentation can be expressed as follow: the basin topograp...The structural styles can be used to analyses and predict developments and distributions of sand bodies in a rift basin. The dynamic process of faulting and sedimentation can be expressed as follow: the basin topography controlled by fault activity can control water dynamics; which in turn affect the transport and sedimentation of sediments. The corresponding analysis between structural styles and sand depositional types includes the following aspects: (1) in section, the corresponding between development of fault terraces and sand depositional types; (2) in plane, the relationship between faults' association and distributions of sand bodies. There are four types of terrace styles to be identified. They are Steep Slope Single Fault Terrace (SSSFT), Steep Slope Multiple Fault Terrace (SSMFT), Gentle Slope (GS) and Gentle Slope Multiple Fault Terrace (GSMFT), which also can be divided into six subtypes by the timing of the faults activities and the directions of their activity migrations (basinward and landward or marginward). They correspond to the following sand depositions such as alluvial fan, fan delta and turbidite fan etc.. The analysis of structure-sedimentation is a discussion on the rank Ⅲ sequence evolution under the condition of pulsing or episodic fault activities. It has been recognized four plane fault associations such as the comb, the broom, the fork and the fault-fold association as well as the corresponding sand distributions. Structural-sedimentary models above mentioned are significant for the deep oil and gas exploration when lacking of the drill data. It may reduce multiple resolutions in the interpretation of seismic-sedimentary facies and promote sand predictions through the constraints of the structural styles of the basin units. The structural-sedimentary pattern can be used as a geological model in oil and gas exploration in the rift basins.展开更多
文摘随着近2年慕课(massive open online course,MOOC)的兴起,教育大数据分析正成为一个新兴的研究方向.2013年秋,北京大学在Coursera上开设了6门慕课.通过分析挖掘约8万多人次参与这6门课的海量学习行为数据,力图展现慕课学习活动多个侧面的风貌.同时,首次针对中文慕课中学习行为的特点,将学习者分类,以更加深入地考察学习行为与学习效果之间的关系.在此基础上,通过选择学习者的若干典型行为特征,对他们最后的学习成果进行预测的工作也尚属首次.数据表明:基于学习行为的特征分析能有效地判别一个学习者能否成功完成学习任务获得通过证书,并能找出潜在的认真学习者,这为今后更加精准的慕课教学测评提供了一种依据.
文摘The structural styles can be used to analyses and predict developments and distributions of sand bodies in a rift basin. The dynamic process of faulting and sedimentation can be expressed as follow: the basin topography controlled by fault activity can control water dynamics; which in turn affect the transport and sedimentation of sediments. The corresponding analysis between structural styles and sand depositional types includes the following aspects: (1) in section, the corresponding between development of fault terraces and sand depositional types; (2) in plane, the relationship between faults' association and distributions of sand bodies. There are four types of terrace styles to be identified. They are Steep Slope Single Fault Terrace (SSSFT), Steep Slope Multiple Fault Terrace (SSMFT), Gentle Slope (GS) and Gentle Slope Multiple Fault Terrace (GSMFT), which also can be divided into six subtypes by the timing of the faults activities and the directions of their activity migrations (basinward and landward or marginward). They correspond to the following sand depositions such as alluvial fan, fan delta and turbidite fan etc.. The analysis of structure-sedimentation is a discussion on the rank Ⅲ sequence evolution under the condition of pulsing or episodic fault activities. It has been recognized four plane fault associations such as the comb, the broom, the fork and the fault-fold association as well as the corresponding sand distributions. Structural-sedimentary models above mentioned are significant for the deep oil and gas exploration when lacking of the drill data. It may reduce multiple resolutions in the interpretation of seismic-sedimentary facies and promote sand predictions through the constraints of the structural styles of the basin units. The structural-sedimentary pattern can be used as a geological model in oil and gas exploration in the rift basins.
