We studied migratory Red-crowned cranes from 1991-2012 in order to track population dynamics and trends for these cranes over time at Shuangtaihekou,northeastern China.Our results show that the earliest arrival date o...We studied migratory Red-crowned cranes from 1991-2012 in order to track population dynamics and trends for these cranes over time at Shuangtaihekou,northeastern China.Our results show that the earliest arrival date of the Red-crowned Crane (Grus japonensis) was usually around 1 March in the spring and the latest departure date of the cranes around 8 November.The peak period for the number of cranes observed in the spring was 10-20 March over these 22 years.The staging period in the spring is about 25 days.Comparing the highest number of Red-crowned cranes observed in the spring,the migratory population was around 400 birds in the 1990s,then,increased to over 800 birds in 2000.For a short while,the population maintained itself around 600-800 birds.After that,the population started to decline,until during the most recent years,we observed around 400 birds at peak times of each season.Our results match a similar population change pattern observed in the wintering area for a western population,which has been declining since 2000.There is an urgent need to reinforce protection and management,as well as to maintain and improve the quality of their habitats.展开更多
Through scanning electron microscope, various trpes of feathers in various parts of red-crown crane--a kind of rare and precious bird were observed micrographically. It was shown in the result that in different type o...Through scanning electron microscope, various trpes of feathers in various parts of red-crown crane--a kind of rare and precious bird were observed micrographically. It was shown in the result that in different type of feather, the barbules show a great variation in their morphology and structure. This observation can be a basic reference for the taxonomy using the feather structure and the study of systematic relationship.展开更多
长尾现象在序列推荐系统中长期存在,包括长尾用户和长尾项目两个方面。虽然现有许多研究缓解了序列推荐系统中的长尾问题,但大部分只是单方面地关注长尾用户或长尾项目。然而,长尾用户和长尾项目问题常常同时存在,只考虑其中一方会导致...长尾现象在序列推荐系统中长期存在,包括长尾用户和长尾项目两个方面。虽然现有许多研究缓解了序列推荐系统中的长尾问题,但大部分只是单方面地关注长尾用户或长尾项目。然而,长尾用户和长尾项目问题常常同时存在,只考虑其中一方会导致另一方性能不佳,且未关注到长尾用户、长尾项目各自的信息匮乏问题。提出一种利用GRU双分支信息协同增强的长尾推荐模型(long-tail recommendation model utilizing gated recurrent unit dualbranch information collaboration enhancement,LT-GRU),从用户与项目两个方面共同缓解长尾问题,并通过协同增强的方式丰富长尾信息。该模型由长尾用户和长尾项目双分支组成,每个分支分别负责各自的信息处理,并相互训练以充实另一方的信息。同时,引入一种偏好机制,通过演算用户与项目的影响因子,以动态调整用户偏好与项目热度,进一步缓解长尾推荐中信息不足问题。在Amazon系列的6个真实数据集上与6种经典模型进行实验对比,相较于长尾推荐模型中最优的结果,所提模型LT-GRU在HR与NDCG两个指标上分别平均提高2.49%、3.80%。这表明,在不牺牲头部用户和热门项目推荐性能的情况下,有效地缓解了长尾用户和长尾项目问题。展开更多
From January to March 2005, the effects of group size on the vigilance behavior of wintering Common Cranes Grus grus were studied at Lashihai Lake, Yunnan Province, China. We used scan sampling to record the group siz...From January to March 2005, the effects of group size on the vigilance behavior of wintering Common Cranes Grus grus were studied at Lashihai Lake, Yunnan Province, China. We used scan sampling to record the group sizes and the number of vigilant individuals in each group, and focal sampling to record the frequency and duration of individual vigilance behavior. Both the vigilance efforts of groups and individuals significantly decreased as group size increased, but when the group size exceeded 30 individuals, the decrease of group vigilance became not significant （P 〉 0. 05）, and the vigilance duration of adult cranes increased （P 〈 0.01 ）. The vigilance frequency of adults increased （P 〈 0.05） when the size exceeded 50 individuals. Presumably, the maximal group size allowing the lowest vigilance for juvenile cranes was larger than that for adults, and the flocks composed of 20 to 30 individuals represented the optimal group size of wintering Common Cranes by considering only the vigilance behavior. Further research should focus on the synthesized effects of various factors.展开更多
The Hooded Crane (Grus monacha) is a waterbird wintering in the wetlands of the middle and lower reaches of the Yangtze River, China. The gradual habitat loss resulting from wetland degradation may have posed negative...The Hooded Crane (Grus monacha) is a waterbird wintering in the wetlands of the middle and lower reaches of the Yangtze River, China. The gradual habitat loss resulting from wetland degradation may have posed negative effects on the structure of our wintering populations. For its effective protection, it is important to conduct an intensive study on the genetic structure of this population. A total of 221 faecal samples, nine feather samples and four muscle samples of Hooded Cranes from four wintering populations, i.e., from Caizi Lake and Shengjin Lake in Anhui, Poyang Lake in Jiangxi and Chongming Dongtan in Shanghai, were collected for this study. Full-length 1103–1104 bp mtDNA D-loop sequences from 72 samples were amplified using PCR. Based on our amplified D-loop sequences and the sequences of two individual birds obtained from GenBank (AB017625 and AB023813), we analyzed the genetic structure of these four wintering Hooded Crane populations. Twenty six variable sites were found among 72 target sequences in the four wintering populations and 23 haplotypes were defined. Genetic diversity analyses showed that the haplotype diversity of Hooded Cranes was 0.823 ± 0.042 with a nucleotide diversity of 0.00157 ± 0.00021. The FST values of the four populations show that there is no significant genetic differentiation among the populations of Hooded Cranes wintering in the middle and lower reaches of the Yangtze River. Tajima’s D and Fu’s tests suggest that the Hooded Crane populations may have experienced population expansion in their evolutionary history.展开更多
The Black-necked Crane (Grus nigricollis) is an endemic species of the Qinghai-Tibetan Plateau,with its population in Xinjiang largely found in the Kunlun and Altun mountain regions.A survey of the distribution,popula...The Black-necked Crane (Grus nigricollis) is an endemic species of the Qinghai-Tibetan Plateau,with its population in Xinjiang largely found in the Kunlun and Altun mountain regions.A survey of the distribution,population dynamics,flock size and behavior was conducted in Altun Mountain National Natural Reserve from September to November 2011.We investigated the size and distribution of its population in this area with a sample spot survey and by direct counting.We found Black-necked Cranes on the wetlands of Wuzunxiaoer,Yusup Aleksei,Yaziquan,Qimantag,Tula Ranch and elsewhere,where we recorded 126 individual birds of the species in Yixiekepati (37° 15′-37°23′N,90°11′-90°20′E,elevation 3903 m),the largest population we have observed in this area.In the reserve,the population consists of about 180-200 birds.Combined with previous records,we conclude that more than 260 Black-necked Cranes live in Xinjiang.Cranes gathered conspicuously in the middle of October where the highest number of birds appeared on 29 October.All of the cranes had migrated out of this area by 6 November.Time budgets and diurnal behavior rhythms of Blacknecked Cranes were observed in the Yixiekepati wetland at daylight (from 06:00 to 18:00).Foraging was the most prevalent type of behavior during the autumn period,accounting for 58.9％ of the diurnal time budget,followed by preening (13.2％),vigilance (9.5％),walking (8.2％),flying (3.5％),resting (3.4％),chirping (2.7％) and other types of behavior (0.6％).展开更多
电池荷电状态(state of charge,SOC)的准确估计近年来成为新能源发展的重中之重,也是电池管理系统(BMS)中最核心的部分。针对改进卡尔曼滤波算法(EKF)与门控循环单元神经网络算法(GRU)的缺陷,提出了一种基于3DGRU?鄄EKF的改进SOC估算算...电池荷电状态(state of charge,SOC)的准确估计近年来成为新能源发展的重中之重,也是电池管理系统(BMS)中最核心的部分。针对改进卡尔曼滤波算法(EKF)与门控循环单元神经网络算法(GRU)的缺陷,提出了一种基于3DGRU?鄄EKF的改进SOC估算算法。首先使用二阶RC电池等效模型,利用复合脉冲功率特性测试(HPPC)进行电池参数辨识;随后对电池模型进行状态空间方程的建立,并利用EKF算法进行更新迭代来估算电池的SOC,可以得到卡尔曼增益与SOC估算误差;最后将2个量结合HPPC工况下的电压与电流作为3DGRU网络的输入,真实的SOC作为输出来训练神经网络。实验结果表明,提出的3DGRU?鄄EKF算法估算SOC的均方根误差(RMSE)与平均绝对误差(MAE)均小于0.5%,具有良好的效果。展开更多
文摘We studied migratory Red-crowned cranes from 1991-2012 in order to track population dynamics and trends for these cranes over time at Shuangtaihekou,northeastern China.Our results show that the earliest arrival date of the Red-crowned Crane (Grus japonensis) was usually around 1 March in the spring and the latest departure date of the cranes around 8 November.The peak period for the number of cranes observed in the spring was 10-20 March over these 22 years.The staging period in the spring is about 25 days.Comparing the highest number of Red-crowned cranes observed in the spring,the migratory population was around 400 birds in the 1990s,then,increased to over 800 birds in 2000.For a short while,the population maintained itself around 600-800 birds.After that,the population started to decline,until during the most recent years,we observed around 400 birds at peak times of each season.Our results match a similar population change pattern observed in the wintering area for a western population,which has been declining since 2000.There is an urgent need to reinforce protection and management,as well as to maintain and improve the quality of their habitats.
文摘Through scanning electron microscope, various trpes of feathers in various parts of red-crown crane--a kind of rare and precious bird were observed micrographically. It was shown in the result that in different type of feather, the barbules show a great variation in their morphology and structure. This observation can be a basic reference for the taxonomy using the feather structure and the study of systematic relationship.
文摘长尾现象在序列推荐系统中长期存在,包括长尾用户和长尾项目两个方面。虽然现有许多研究缓解了序列推荐系统中的长尾问题,但大部分只是单方面地关注长尾用户或长尾项目。然而,长尾用户和长尾项目问题常常同时存在,只考虑其中一方会导致另一方性能不佳,且未关注到长尾用户、长尾项目各自的信息匮乏问题。提出一种利用GRU双分支信息协同增强的长尾推荐模型(long-tail recommendation model utilizing gated recurrent unit dualbranch information collaboration enhancement,LT-GRU),从用户与项目两个方面共同缓解长尾问题,并通过协同增强的方式丰富长尾信息。该模型由长尾用户和长尾项目双分支组成,每个分支分别负责各自的信息处理,并相互训练以充实另一方的信息。同时,引入一种偏好机制,通过演算用户与项目的影响因子,以动态调整用户偏好与项目热度,进一步缓解长尾推荐中信息不足问题。在Amazon系列的6个真实数据集上与6种经典模型进行实验对比,相较于长尾推荐模型中最优的结果,所提模型LT-GRU在HR与NDCG两个指标上分别平均提高2.49%、3.80%。这表明,在不牺牲头部用户和热门项目推荐性能的情况下,有效地缓解了长尾用户和长尾项目问题。
文摘From January to March 2005, the effects of group size on the vigilance behavior of wintering Common Cranes Grus grus were studied at Lashihai Lake, Yunnan Province, China. We used scan sampling to record the group sizes and the number of vigilant individuals in each group, and focal sampling to record the frequency and duration of individual vigilance behavior. Both the vigilance efforts of groups and individuals significantly decreased as group size increased, but when the group size exceeded 30 individuals, the decrease of group vigilance became not significant （P 〉 0. 05）, and the vigilance duration of adult cranes increased （P 〈 0.01 ）. The vigilance frequency of adults increased （P 〈 0.05） when the size exceeded 50 individuals. Presumably, the maximal group size allowing the lowest vigilance for juvenile cranes was larger than that for adults, and the flocks composed of 20 to 30 individuals represented the optimal group size of wintering Common Cranes by considering only the vigilance behavior. Further research should focus on the synthesized effects of various factors.
基金supported by the National Natural Science Foundation of China (Grant No 31172117)the Anhui Academic and Technical Leaders Fund
文摘The Hooded Crane (Grus monacha) is a waterbird wintering in the wetlands of the middle and lower reaches of the Yangtze River, China. The gradual habitat loss resulting from wetland degradation may have posed negative effects on the structure of our wintering populations. For its effective protection, it is important to conduct an intensive study on the genetic structure of this population. A total of 221 faecal samples, nine feather samples and four muscle samples of Hooded Cranes from four wintering populations, i.e., from Caizi Lake and Shengjin Lake in Anhui, Poyang Lake in Jiangxi and Chongming Dongtan in Shanghai, were collected for this study. Full-length 1103–1104 bp mtDNA D-loop sequences from 72 samples were amplified using PCR. Based on our amplified D-loop sequences and the sequences of two individual birds obtained from GenBank (AB017625 and AB023813), we analyzed the genetic structure of these four wintering Hooded Crane populations. Twenty six variable sites were found among 72 target sequences in the four wintering populations and 23 haplotypes were defined. Genetic diversity analyses showed that the haplotype diversity of Hooded Cranes was 0.823 ± 0.042 with a nucleotide diversity of 0.00157 ± 0.00021. The FST values of the four populations show that there is no significant genetic differentiation among the populations of Hooded Cranes wintering in the middle and lower reaches of the Yangtze River. Tajima’s D and Fu’s tests suggest that the Hooded Crane populations may have experienced population expansion in their evolutionary history.
基金supported by the National Natural Science Foundation of China(No.31272291,30970340)the Hong Kong Bird Watching Society China Conservation Fund and the Management Bureau of Altun Mountain Natural Reserve
文摘The Black-necked Crane (Grus nigricollis) is an endemic species of the Qinghai-Tibetan Plateau,with its population in Xinjiang largely found in the Kunlun and Altun mountain regions.A survey of the distribution,population dynamics,flock size and behavior was conducted in Altun Mountain National Natural Reserve from September to November 2011.We investigated the size and distribution of its population in this area with a sample spot survey and by direct counting.We found Black-necked Cranes on the wetlands of Wuzunxiaoer,Yusup Aleksei,Yaziquan,Qimantag,Tula Ranch and elsewhere,where we recorded 126 individual birds of the species in Yixiekepati (37° 15′-37°23′N,90°11′-90°20′E,elevation 3903 m),the largest population we have observed in this area.In the reserve,the population consists of about 180-200 birds.Combined with previous records,we conclude that more than 260 Black-necked Cranes live in Xinjiang.Cranes gathered conspicuously in the middle of October where the highest number of birds appeared on 29 October.All of the cranes had migrated out of this area by 6 November.Time budgets and diurnal behavior rhythms of Blacknecked Cranes were observed in the Yixiekepati wetland at daylight (from 06:00 to 18:00).Foraging was the most prevalent type of behavior during the autumn period,accounting for 58.9％ of the diurnal time budget,followed by preening (13.2％),vigilance (9.5％),walking (8.2％),flying (3.5％),resting (3.4％),chirping (2.7％) and other types of behavior (0.6％).
文摘电池荷电状态(state of charge,SOC)的准确估计近年来成为新能源发展的重中之重,也是电池管理系统(BMS)中最核心的部分。针对改进卡尔曼滤波算法(EKF)与门控循环单元神经网络算法(GRU)的缺陷,提出了一种基于3DGRU?鄄EKF的改进SOC估算算法。首先使用二阶RC电池等效模型,利用复合脉冲功率特性测试(HPPC)进行电池参数辨识;随后对电池模型进行状态空间方程的建立,并利用EKF算法进行更新迭代来估算电池的SOC,可以得到卡尔曼增益与SOC估算误差;最后将2个量结合HPPC工况下的电压与电流作为3DGRU网络的输入,真实的SOC作为输出来训练神经网络。实验结果表明,提出的3DGRU?鄄EKF算法估算SOC的均方根误差(RMSE)与平均绝对误差(MAE)均小于0.5%,具有良好的效果。
