For the urban built environment,the shape characteristics of the external space are of decisive significance.However,what is commonly referred to as open space is more of a definition of social attributes.Therefore,in...For the urban built environment,the shape characteristics of the external space are of decisive significance.However,what is commonly referred to as open space is more of a definition of social attributes.Therefore,in the research on urban environments,especially in urban micro-climate,the study of a microclimate’s correlation with open space easily produces deviations.The identification of the openness of an external space based on a direct quantitative description is an important prerequisite for the cognitive urban form.In this study,based on the height-to-width ratio(HWR)of different directional sections of external space,areas with high openness in an urban space are extracted by the threshold value.In the case analysis of different areas in Nanjing,China,the results showed that the method is effective and convenient.The results of the analysis can also be used more widely in the urban design and research.展开更多
This paper studies the short-term prediction methods of sectional passenger flow, and selects BP neural network combined with the characteristics of sectional passenger flow itself. With a case study, we design three ...This paper studies the short-term prediction methods of sectional passenger flow, and selects BP neural network combined with the characteristics of sectional passenger flow itself. With a case study, we design three different schemes. We use Matlab to realize the prediction of the sectional passenger flow of the Beijing subway Line 2 and make comparative analysis. The empirical research shows that combining data characteristics of sectional passenger flow with the BP neural network have good prediction accuracy.展开更多
Background: Six in ten sexually active adolescent women in Uganda have an unmet need for contraception yet there is limited data on what is driving its use. This study aimed to determine the associations between socio...Background: Six in ten sexually active adolescent women in Uganda have an unmet need for contraception yet there is limited data on what is driving its use. This study aimed to determine the associations between sociodemographic factors and modern contraceptive ever-use among adolescents in Uganda. Methods: A crossectional study was conducted among 337 adolescents aged 13 - 19 years who had ever had sex in Wakiso (urban) and Kamuli (rural) districts in Uganda. The outcome of interest was the ever-use of modern contraceptives. Generalized linear models with a Poisson link were used to examine the associations between sociodemographic factors and contraceptive ever use. Results: The weighted prevalence of ever-use of modern contraceptives was 30.9%. Contraceptive ever use was more likely among the older adolescents (adjusted Odds Ratio) aOR 1.31 (95% CI = 1.06 - 1.55), married aOR 1.67 (95% CI = 1.09 - 2.58) and the less educated were aOR 1.79 (95% CI = 1.14 - 2.83) compared to their counterparts. Adolescents living in the urban district (Wakiso) aOR 0.67 (95% CI = 0.49 - 0.92) were less likely to use modern contraceptives. In stratified analysis, the urban poor were more likely to use modern contraceptives (moderate aPR 0.35 95%CI (0.17 - 0.68) ** or high socioeconomic status aPR 0.62, 95%CI (0.28 - 1.37). Conclusions: The study shows low contraceptive ever-use among adolescents. Adolescents with low education and those from rural settings were more likely to ever-use modern contraceptives. Having good knowledge of contraception and discussing sex with parents promoted contraceptives ever-use. We recommend further studies assessing barriers to contraceptive use among adolescents in Uganda.展开更多
轨道交通网络中乘客的出行受网络结构和运营状况变化的影响,个体出行偏好对这些变化的响应也各异。为分析轨道交通远郊区段计划性停运对常乘客的出行转移影响,本文提出考虑转移类型和转移比例的乘客出行特征刻画方法,结合时段属性生成...轨道交通网络中乘客的出行受网络结构和运营状况变化的影响,个体出行偏好对这些变化的响应也各异。为分析轨道交通远郊区段计划性停运对常乘客的出行转移影响,本文提出考虑转移类型和转移比例的乘客出行特征刻画方法,结合时段属性生成乘客特征—时序(FeatureTemporal,F-T)矩阵;通过改进的欧氏距离计算F-T矩阵间的相似性,实现F-T矩阵的相似性度量;提出一种基于相似度矩阵的K-Means聚类和层次聚类相结合的两步聚类方法(Two-step Clustering of K-Means Clustering and Hierarchical Clustering,KMHC)划分乘客影响群体,分析影响乘客出行转移的因素;以新冠肺炎疫情期间上海轨道交通11号线昆山段停运作为实例,对本文方法进行验证。研究结果表明:昆山段停运后,常乘客呈现出5种主要的出行转移影响群体,占常乘客总数的94.4%;各影响群体的转移距离、通勤时间和出行频率差异明显,是影响区段停运后常乘客出行选择的重要因素。本文方法可为其他计划性停运场景提供借鉴和参考,也可为区段停运后的网络客流变化预测,行车和客运组织方案优化提供支撑。展开更多
基金This research was funded by the National Natural Science Foundation of China[grant number 51578277]the Major Program of National Natural Science Foundation of China[grant number 51538005].
文摘For the urban built environment,the shape characteristics of the external space are of decisive significance.However,what is commonly referred to as open space is more of a definition of social attributes.Therefore,in the research on urban environments,especially in urban micro-climate,the study of a microclimate’s correlation with open space easily produces deviations.The identification of the openness of an external space based on a direct quantitative description is an important prerequisite for the cognitive urban form.In this study,based on the height-to-width ratio(HWR)of different directional sections of external space,areas with high openness in an urban space are extracted by the threshold value.In the case analysis of different areas in Nanjing,China,the results showed that the method is effective and convenient.The results of the analysis can also be used more widely in the urban design and research.
文摘This paper studies the short-term prediction methods of sectional passenger flow, and selects BP neural network combined with the characteristics of sectional passenger flow itself. With a case study, we design three different schemes. We use Matlab to realize the prediction of the sectional passenger flow of the Beijing subway Line 2 and make comparative analysis. The empirical research shows that combining data characteristics of sectional passenger flow with the BP neural network have good prediction accuracy.
文摘Background: Six in ten sexually active adolescent women in Uganda have an unmet need for contraception yet there is limited data on what is driving its use. This study aimed to determine the associations between sociodemographic factors and modern contraceptive ever-use among adolescents in Uganda. Methods: A crossectional study was conducted among 337 adolescents aged 13 - 19 years who had ever had sex in Wakiso (urban) and Kamuli (rural) districts in Uganda. The outcome of interest was the ever-use of modern contraceptives. Generalized linear models with a Poisson link were used to examine the associations between sociodemographic factors and contraceptive ever use. Results: The weighted prevalence of ever-use of modern contraceptives was 30.9%. Contraceptive ever use was more likely among the older adolescents (adjusted Odds Ratio) aOR 1.31 (95% CI = 1.06 - 1.55), married aOR 1.67 (95% CI = 1.09 - 2.58) and the less educated were aOR 1.79 (95% CI = 1.14 - 2.83) compared to their counterparts. Adolescents living in the urban district (Wakiso) aOR 0.67 (95% CI = 0.49 - 0.92) were less likely to use modern contraceptives. In stratified analysis, the urban poor were more likely to use modern contraceptives (moderate aPR 0.35 95%CI (0.17 - 0.68) ** or high socioeconomic status aPR 0.62, 95%CI (0.28 - 1.37). Conclusions: The study shows low contraceptive ever-use among adolescents. Adolescents with low education and those from rural settings were more likely to ever-use modern contraceptives. Having good knowledge of contraception and discussing sex with parents promoted contraceptives ever-use. We recommend further studies assessing barriers to contraceptive use among adolescents in Uganda.
文摘轨道交通网络中乘客的出行受网络结构和运营状况变化的影响,个体出行偏好对这些变化的响应也各异。为分析轨道交通远郊区段计划性停运对常乘客的出行转移影响,本文提出考虑转移类型和转移比例的乘客出行特征刻画方法,结合时段属性生成乘客特征—时序(FeatureTemporal,F-T)矩阵;通过改进的欧氏距离计算F-T矩阵间的相似性,实现F-T矩阵的相似性度量;提出一种基于相似度矩阵的K-Means聚类和层次聚类相结合的两步聚类方法(Two-step Clustering of K-Means Clustering and Hierarchical Clustering,KMHC)划分乘客影响群体,分析影响乘客出行转移的因素;以新冠肺炎疫情期间上海轨道交通11号线昆山段停运作为实例,对本文方法进行验证。研究结果表明:昆山段停运后,常乘客呈现出5种主要的出行转移影响群体,占常乘客总数的94.4%;各影响群体的转移距离、通勤时间和出行频率差异明显,是影响区段停运后常乘客出行选择的重要因素。本文方法可为其他计划性停运场景提供借鉴和参考,也可为区段停运后的网络客流变化预测,行车和客运组织方案优化提供支撑。
