在物流供应商选择过程中,针对分布式评价语言环境下专家评价信息不完整问题,提出社会网络下考虑信息补全的群决策方法。考虑专家接受间接信任关系可能性的大小,提出一种新的信任传递模型来完善专家间的信任值;首次拓展Jensen-Shannon散...在物流供应商选择过程中,针对分布式评价语言环境下专家评价信息不完整问题,提出社会网络下考虑信息补全的群决策方法。考虑专家接受间接信任关系可能性的大小,提出一种新的信任传递模型来完善专家间的信任值;首次拓展Jensen-Shannon散度到分布式评价语言距离度量上,用于衡量专家之间的相似度;基于K-临近算法,设计改进的残缺评价信息补全方法;对专家信息进行集结并构建共识度量与反馈调节机制,得到群决策矩阵,并运用改进的EDAS(evaluation based on distance from average solution,离平均方案(平均解)距离)方法对方案进行排序;通过物流服务供应商综合评估算例验证该群决策方法的可行性和有效性。展开更多
相较于暴雨这种日尺度强降水,短时强降水(≥20 mm h^(−1))是造成山洪滑坡与城市内涝等灾害更为直接的因素。本文利用地面气象观测站和ERA5再分析数据,重点研究南海季风爆发前后珠江三角洲地区(简称珠三角)短时强降水的时空演变特征,并...相较于暴雨这种日尺度强降水,短时强降水(≥20 mm h^(−1))是造成山洪滑坡与城市内涝等灾害更为直接的因素。本文利用地面气象观测站和ERA5再分析数据,重点研究南海季风爆发前后珠江三角洲地区(简称珠三角)短时强降水的时空演变特征,并探索了短时强降水在季风爆发前后特征差异的可能成因。研究表明:(1)相较于季风爆发前,珠三角地区季风爆发后的降水明显增多,其中短时强降水贡献的比例显著增加。对短时强降水本身而言,区域平均强度以及极端性在季风爆发前后差异总体较小,但短时强降水频率在季风爆发后增加70%。(2)短时强降水高发区主要集中在珠三角东北部和珠江口西侧沿海,季风爆发后上述两个地区的频次增多最明显。短时强降水频率由季风爆发前的单峰型(下午)转为季风爆发后的双峰型(早晨与下午)。(3)短时强降水具有明显的区域性变化特征,短时强降水在季风爆发后的平均雨强和极端性在珠江口西侧沿海较内陆地区明显增强,其频次峰值时间在沿海地区从季风爆发前的午后转为季风爆发后的早晨,内陆地区在季风爆发前后均集中在下午。(4)季风爆发后,短时强降水期间的低层环境水汽超过同期气候态水平的16%。充沛的水汽在夜间在季风加速作用下被输送至沿海,并与陆风作用增强了辐合,这解释了沿海短时强降水的在季风爆发前后频次峰值时间转换现象。(5)相较于季风爆发前,季风爆发后珠三角短时强降水频率与低层水汽通量的相关性明显升高。珠三角沿海地区夜间—早晨短时强降水的增多与中低层风场结构改变造成的动力强迫有关。内陆地区季风爆发前后短时强降水与环境热力和不稳定条件关系更大。这些结果有助于我们更好地了解珠三角地区在季风爆发前后短时强降水的时空分布特征和理解其产生机制。展开更多
The near field of underwater target acoustic scattering is a time-space distribution.Its characteristics can be illustrated by target time(equivalent to position)-aspect 2-dimensional highlight distribution. The princ...The near field of underwater target acoustic scattering is a time-space distribution.Its characteristics can be illustrated by target time(equivalent to position)-aspect 2-dimensional highlight distribution. The principle that based on acoustic channel theory is reported here.Conjoining with sea trial results, some main reasons of target scattering are reviewed. The graphs for the target 2-dimensional highlight distribution are also discussed. Finally, the physical model of target 2-dimensional highlight distribution is presented.展开更多
In this article,mathematical modeling for the evaluation of reliability is studied using two methods.One of the methods,is developed based on possibility theory.The performance of the reliability of the system is of p...In this article,mathematical modeling for the evaluation of reliability is studied using two methods.One of the methods,is developed based on possibility theory.The performance of the reliability of the system is of prime concern.In view of this,the outcomes for the failure are required to evaluate with utmost care.In possibility theory,the reliability information data determined from decision-making experts are subjective.The samemethod is also related to the survival possibilities as against the survival probabilities.The other method is the one that is developed using the concept of approximation of closed interval including the piecewise quadratic fuzzy numbers.In this method,a decision-making expert is not sure of his/her estimates of the reliability parameters.Numerical experiments are performed to illustrate the efficiency of the suggested methods in this research.In the end,the paper is concluded with some future research directions to be explored for the proposed approach.展开更多
During the April-June raining season,warm-sector heavy rainfall(WR) and frontal heavy rainfall(FR) often occur in the south of China,causing natural disasters.In this study,the microphysical characteristics of WR and ...During the April-June raining season,warm-sector heavy rainfall(WR) and frontal heavy rainfall(FR) often occur in the south of China,causing natural disasters.In this study,the microphysical characteristics of WR and FR events from 2016 to 2022 are analyzed by using 2-dimensional video disdrometer(2DVD) data in the south of China.The microphysical characteristics of WR and FR events are quite different.Compared with FR events,WR events have higher concentration of D<5.3 mm(especially D <1 mm),leading to higher rain rates.The mean values of Dmand lgNwof WR events are higher than that of FR events.The microphysical characteristics in different rain rate classes(C1:R~5-20 mm h-1,C2:R~20-50 mm h-1,C3:R~50-100 mm h^(-1),and C4:R> 100 mm h^(-1)) for WR and FR events are also different.Raindrops from C3 contribute the most to the precipitation of WR events,and raindrops from C2 contribute the most to the precipitation of FR events.For C2 and C3,compared with FR events,WR events have higher concentration of D <1 mm and D~3-4.5 mm.Moreover,the shape and slope(μ-A) relationships and the radar reflectivity and rain rate(Z-R) relationships of WR and FR events are quite different in each rain rate class.The investigation of the difference in microphysical characteristics between WR and FR events provide useful information for radar-based quantitative precipitation estimation and numerical prediction.展开更多
文摘在物流供应商选择过程中,针对分布式评价语言环境下专家评价信息不完整问题,提出社会网络下考虑信息补全的群决策方法。考虑专家接受间接信任关系可能性的大小,提出一种新的信任传递模型来完善专家间的信任值;首次拓展Jensen-Shannon散度到分布式评价语言距离度量上,用于衡量专家之间的相似度;基于K-临近算法,设计改进的残缺评价信息补全方法;对专家信息进行集结并构建共识度量与反馈调节机制,得到群决策矩阵,并运用改进的EDAS(evaluation based on distance from average solution,离平均方案(平均解)距离)方法对方案进行排序;通过物流服务供应商综合评估算例验证该群决策方法的可行性和有效性。
文摘相较于暴雨这种日尺度强降水,短时强降水(≥20 mm h^(−1))是造成山洪滑坡与城市内涝等灾害更为直接的因素。本文利用地面气象观测站和ERA5再分析数据,重点研究南海季风爆发前后珠江三角洲地区(简称珠三角)短时强降水的时空演变特征,并探索了短时强降水在季风爆发前后特征差异的可能成因。研究表明:(1)相较于季风爆发前,珠三角地区季风爆发后的降水明显增多,其中短时强降水贡献的比例显著增加。对短时强降水本身而言,区域平均强度以及极端性在季风爆发前后差异总体较小,但短时强降水频率在季风爆发后增加70%。(2)短时强降水高发区主要集中在珠三角东北部和珠江口西侧沿海,季风爆发后上述两个地区的频次增多最明显。短时强降水频率由季风爆发前的单峰型(下午)转为季风爆发后的双峰型(早晨与下午)。(3)短时强降水具有明显的区域性变化特征,短时强降水在季风爆发后的平均雨强和极端性在珠江口西侧沿海较内陆地区明显增强,其频次峰值时间在沿海地区从季风爆发前的午后转为季风爆发后的早晨,内陆地区在季风爆发前后均集中在下午。(4)季风爆发后,短时强降水期间的低层环境水汽超过同期气候态水平的16%。充沛的水汽在夜间在季风加速作用下被输送至沿海,并与陆风作用增强了辐合,这解释了沿海短时强降水的在季风爆发前后频次峰值时间转换现象。(5)相较于季风爆发前,季风爆发后珠三角短时强降水频率与低层水汽通量的相关性明显升高。珠三角沿海地区夜间—早晨短时强降水的增多与中低层风场结构改变造成的动力强迫有关。内陆地区季风爆发前后短时强降水与环境热力和不稳定条件关系更大。这些结果有助于我们更好地了解珠三角地区在季风爆发前后短时强降水的时空分布特征和理解其产生机制。
文摘The near field of underwater target acoustic scattering is a time-space distribution.Its characteristics can be illustrated by target time(equivalent to position)-aspect 2-dimensional highlight distribution. The principle that based on acoustic channel theory is reported here.Conjoining with sea trial results, some main reasons of target scattering are reviewed. The graphs for the target 2-dimensional highlight distribution are also discussed. Finally, the physical model of target 2-dimensional highlight distribution is presented.
文摘In this article,mathematical modeling for the evaluation of reliability is studied using two methods.One of the methods,is developed based on possibility theory.The performance of the reliability of the system is of prime concern.In view of this,the outcomes for the failure are required to evaluate with utmost care.In possibility theory,the reliability information data determined from decision-making experts are subjective.The samemethod is also related to the survival possibilities as against the survival probabilities.The other method is the one that is developed using the concept of approximation of closed interval including the piecewise quadratic fuzzy numbers.In this method,a decision-making expert is not sure of his/her estimates of the reliability parameters.Numerical experiments are performed to illustrate the efficiency of the suggested methods in this research.In the end,the paper is concluded with some future research directions to be explored for the proposed approach.
基金National key research and development program of China(2022YFC3003902)National Natural Science Foundation of China(U2242203,42075086,41975138)Guangdong Basic and Applied Basic Research Foundation(2023A1515011971,2021A1515011415,2019A1515010814)。
文摘During the April-June raining season,warm-sector heavy rainfall(WR) and frontal heavy rainfall(FR) often occur in the south of China,causing natural disasters.In this study,the microphysical characteristics of WR and FR events from 2016 to 2022 are analyzed by using 2-dimensional video disdrometer(2DVD) data in the south of China.The microphysical characteristics of WR and FR events are quite different.Compared with FR events,WR events have higher concentration of D<5.3 mm(especially D <1 mm),leading to higher rain rates.The mean values of Dmand lgNwof WR events are higher than that of FR events.The microphysical characteristics in different rain rate classes(C1:R~5-20 mm h-1,C2:R~20-50 mm h-1,C3:R~50-100 mm h^(-1),and C4:R> 100 mm h^(-1)) for WR and FR events are also different.Raindrops from C3 contribute the most to the precipitation of WR events,and raindrops from C2 contribute the most to the precipitation of FR events.For C2 and C3,compared with FR events,WR events have higher concentration of D <1 mm and D~3-4.5 mm.Moreover,the shape and slope(μ-A) relationships and the radar reflectivity and rain rate(Z-R) relationships of WR and FR events are quite different in each rain rate class.The investigation of the difference in microphysical characteristics between WR and FR events provide useful information for radar-based quantitative precipitation estimation and numerical prediction.
