终端区航空器的飞行密度和复杂度较高,此管制区域的处理能力是制约航空体系效率的瓶颈,对进场航空器管制效率进行量化研究,有助于提高管制工作处理能力和质量。首先,提出以区域导航(RNAV,regional area navigation)标准仪表进场程序的...终端区航空器的飞行密度和复杂度较高,此管制区域的处理能力是制约航空体系效率的瓶颈,对进场航空器管制效率进行量化研究,有助于提高管制工作处理能力和质量。首先,提出以区域导航(RNAV,regional area navigation)标准仪表进场程序的标称里程为计算基准量化进场管制效率,通过随机搜索聚类算法的结果得到航空器使用的RNAV标准仪表进场程序,选用在北京首都国际机场着陆的航空器为分析对象,计算航空器的进场管制效率,结合航迹讨论不同RNAV标准仪表进场程序下航空器的运行方式及特点。其次,对进场管制效率的影响因素进行分析,并采用灰色关联分析法量化各影响因素的影响程度与权重,结果显示:雷达引导度和航行三要素改变次数对进场管制效率具有显著影响,飞行流量和RNAV标准仪表进场程序的标称里程对进场管制效率的影响相对较小。继而,从影响因素角度出发评估整体进场管制效率,得到更为全面客观的整体进场管制效率。最后,尝试从RNAV进场程序路径以及优良管制行为模式两方面寻求进场管制效率的提升途径和方法。展开更多
Benzodiazepines(BDZs)are used in clinics for anxiolysis,anticonvulsants,sedative hypnosis,and muscle relaxation.They have high consumptions worldwide because of their easy availability and potential addiction.They are...Benzodiazepines(BDZs)are used in clinics for anxiolysis,anticonvulsants,sedative hypnosis,and muscle relaxation.They have high consumptions worldwide because of their easy availability and potential addiction.They are often used for suicide or criminal practices such as abduction and drug-facilitated sexual assault.The pharmacological effects of using small doses of BDZs and their detections from complex biological matrices are challenging.Efficient pretreatment methods followed by accurate and sensitive detections are necessary.Herein,pretreatment methods for the extraction,enrichment,and preconcentration of BDZs as well as the strategies for their screening,identification,and quantitation developed in the past five years have been reviewed.Moreover,recent advances in various methods are summarized.Characteristics and advantages of each method are encompassed.Future directions of the pretreatment and detection methods for BDZs are also reviewed.展开更多
为找到涵盖比较全面的各组类具有代表性的中心航迹,需要对航迹进行分类分析。首先介绍针对得到的航空器轨迹数据的处理方法及流程,并进行重要数据的转换和提取,标画出实际飞行总航迹。然后运用基于空间相似距离的k均值聚类算法进行聚类...为找到涵盖比较全面的各组类具有代表性的中心航迹,需要对航迹进行分类分析。首先介绍针对得到的航空器轨迹数据的处理方法及流程,并进行重要数据的转换和提取,标画出实际飞行总航迹。然后运用基于空间相似距离的k均值聚类算法进行聚类分析,并通过动态时间规整(dynamic time warping,DTW)算法对航迹聚类不同K取值的分类结果进行相似性度量,确定合适的K值,从而在众多航迹中将实际飞行航迹按照空间运行的相似性进行归类处理,找到中心航迹,实现航迹的分类。应用北京首都国际机场36L跑道上着陆航空器的航迹数据进行算例分析,分析结果证明,该算法可以有效地对航迹进行分类分析。展开更多
文摘终端区航空器的飞行密度和复杂度较高,此管制区域的处理能力是制约航空体系效率的瓶颈,对进场航空器管制效率进行量化研究,有助于提高管制工作处理能力和质量。首先,提出以区域导航(RNAV,regional area navigation)标准仪表进场程序的标称里程为计算基准量化进场管制效率,通过随机搜索聚类算法的结果得到航空器使用的RNAV标准仪表进场程序,选用在北京首都国际机场着陆的航空器为分析对象,计算航空器的进场管制效率,结合航迹讨论不同RNAV标准仪表进场程序下航空器的运行方式及特点。其次,对进场管制效率的影响因素进行分析,并采用灰色关联分析法量化各影响因素的影响程度与权重,结果显示:雷达引导度和航行三要素改变次数对进场管制效率具有显著影响,飞行流量和RNAV标准仪表进场程序的标称里程对进场管制效率的影响相对较小。继而,从影响因素角度出发评估整体进场管制效率,得到更为全面客观的整体进场管制效率。最后,尝试从RNAV进场程序路径以及优良管制行为模式两方面寻求进场管制效率的提升途径和方法。
基金supported by the Scientific Research Project of the Department of Education of Liaoning Province,China(Grant No.:ZF2019036).
文摘Benzodiazepines(BDZs)are used in clinics for anxiolysis,anticonvulsants,sedative hypnosis,and muscle relaxation.They have high consumptions worldwide because of their easy availability and potential addiction.They are often used for suicide or criminal practices such as abduction and drug-facilitated sexual assault.The pharmacological effects of using small doses of BDZs and their detections from complex biological matrices are challenging.Efficient pretreatment methods followed by accurate and sensitive detections are necessary.Herein,pretreatment methods for the extraction,enrichment,and preconcentration of BDZs as well as the strategies for their screening,identification,and quantitation developed in the past five years have been reviewed.Moreover,recent advances in various methods are summarized.Characteristics and advantages of each method are encompassed.Future directions of the pretreatment and detection methods for BDZs are also reviewed.
文摘为找到涵盖比较全面的各组类具有代表性的中心航迹,需要对航迹进行分类分析。首先介绍针对得到的航空器轨迹数据的处理方法及流程,并进行重要数据的转换和提取,标画出实际飞行总航迹。然后运用基于空间相似距离的k均值聚类算法进行聚类分析,并通过动态时间规整(dynamic time warping,DTW)算法对航迹聚类不同K取值的分类结果进行相似性度量,确定合适的K值,从而在众多航迹中将实际飞行航迹按照空间运行的相似性进行归类处理,找到中心航迹,实现航迹的分类。应用北京首都国际机场36L跑道上着陆航空器的航迹数据进行算例分析,分析结果证明,该算法可以有效地对航迹进行分类分析。
