China is a traditional agriculture based country and one main region for crop production is southeastern China where temperature is a dominant climate variable affecting agriculture. Temperature and social disturbance...China is a traditional agriculture based country and one main region for crop production is southeastern China where temperature is a dominant climate variable affecting agriculture. Temperature and social disturbances both influence crop production, yet distinguishing their relative impacts is difficult due to a lack of reliable, high-resolution historical climatic records before the very recent period. Here we present the first tree-ring based warm-season temperature reconstruction for southeastern China, a core region of the East Asian monsoon, for the past 227 years. The reconstruction target was April-July mean temperature, and our model explained 60.6% of the observed temperature variance during 1953–2012.Spatial correlation analysis showed that the reconstruction is representative of April-July temperature change over most of eastern China. The reconstructed temperature series agrees well with China-scale(heavily weighted in eastern China) agricultural production index values quite well at decadal timescales.The impacts of social upheavals on food production, such as those in the period 1920–1949, were confirmed after climatic influences were excluded. Our study should help distinguish the influence of social disturbance and warm-season temperature on grain productivity in the core agricultural region of China during the past two centuries.展开更多
为解决现有的防御链接预测攻击的隐私保护方法的不足,提出一种基于积分梯度的局部扰动算法LDIG(local disturbance algorithm based on integral gradient)。利用敏感链接的闭合子图确定扰动范围,根据扰动范围内链接的积分梯度迭代扰动...为解决现有的防御链接预测攻击的隐私保护方法的不足,提出一种基于积分梯度的局部扰动算法LDIG(local disturbance algorithm based on integral gradient)。利用敏感链接的闭合子图确定扰动范围,根据扰动范围内链接的积分梯度迭代扰动链接,同时将链接预测对扰动图中敏感链接的预测结果作为扰动结束的判断依据。实验结果表明,LDIG算法的计算复杂度较低,适用于大规模社交网络的隐私保护,扰动链接的数量较少,提高了数据的效用性。展开更多
We propose pro-social control strategies for connected automated vehicles(CAVs)to mitigate jamming waves in mixed-autonomy multi-lane traffic,resulting from car-following dynamics of human-driven vehicles(HDVs).Differ...We propose pro-social control strategies for connected automated vehicles(CAVs)to mitigate jamming waves in mixed-autonomy multi-lane traffic,resulting from car-following dynamics of human-driven vehicles(HDVs).Different from existing studies,which focus mostly on ego vehicle objectives to control CAVs in an individualistic manner,we devise a pro-social control algorithm.The latter takes into account the objectives(i.e.,driving comfort and traffic efficiency)of both the ego vehicle and surrounding HDVs to improve smoothness of the entire observable traffic.Under a model predictive control(MPC)framework that uses acceleration and lane change sequences of CAVs as optimization variables,the problem of individualistic,altruistic,and pro-social control is formulated as a non-convex mixed-integer nonlinear program(MINLP)and relaxed to a convex quadratic program through converting the piece-wise-linear constraints due to the optimal velocity with relative velocity(OVRV)car-following model into linear constraints by introducing slack variables.Low-fidelity simulations using the OVRV model and high-fidelity simulations using PTV VISSIM simulator show that pro-social and altruistic control can provide significant performance gains over individualistic driving in terms of efficiency and comfort on both single-and multi-lane roads.展开更多
Behavioural lateralization,which reflects the functional specializations of the two brain hemispheres,is assumed to play an important role in cooperative intraspecific interactions.However,there are few studies focuse...Behavioural lateralization,which reflects the functional specializations of the two brain hemispheres,is assumed to play an important role in cooperative intraspecific interactions.However,there are few studies focused on the lateralization in cooperative behaviours of individuals,especially in a natural setting.In the present study,we investigated Iateralized spatial interactions between the partners in life-long monogamous pairs.The male-female pairs of two geese species(barnacle,Branta leucopsis,and white-fronted,Anser albifrons geese),were observed during different stages of the annual cycle in a variety of conditions.In geese flocks,we recorded which visual hemifield(left/right)the following partner used to monitor the leading partner relevant to the type of behaviour and the disturbance factors.In a significant majority of pairs,the following bird viewed the leading partner with the left eye during routine behaviours such as resting and feeding in undisturbed conditions.This behavioural lateralization,implicating the right hemisphere processing,was consistent across the different aggregation sites and years of the study.In contrast,no significant bias was found in a variety of geese behaviours associated with enhanced disturbance(when alert on water,flying or fleeing away when disturbed,feeding during the hunting period,in urban area feeding and during moulting).We hypothesize that the increased demands for right hemisphere processing to deal with stressful and emergency situations may interfere with the manifestation of lateralization in social interactions.展开更多
基金supported by National Natural Science Foundation of China Project (41271210)the National Key R&D Program of China (2016YFA0600503)+3 种基金the Fundamental Research Funds for the Central Universities (20620140083)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Jiangsu Collaborative Innovation Center for Climate ChangeUNESCO CHINA-4500193250
文摘China is a traditional agriculture based country and one main region for crop production is southeastern China where temperature is a dominant climate variable affecting agriculture. Temperature and social disturbances both influence crop production, yet distinguishing their relative impacts is difficult due to a lack of reliable, high-resolution historical climatic records before the very recent period. Here we present the first tree-ring based warm-season temperature reconstruction for southeastern China, a core region of the East Asian monsoon, for the past 227 years. The reconstruction target was April-July mean temperature, and our model explained 60.6% of the observed temperature variance during 1953–2012.Spatial correlation analysis showed that the reconstruction is representative of April-July temperature change over most of eastern China. The reconstructed temperature series agrees well with China-scale(heavily weighted in eastern China) agricultural production index values quite well at decadal timescales.The impacts of social upheavals on food production, such as those in the period 1920–1949, were confirmed after climatic influences were excluded. Our study should help distinguish the influence of social disturbance and warm-season temperature on grain productivity in the core agricultural region of China during the past two centuries.
文摘为解决现有的防御链接预测攻击的隐私保护方法的不足,提出一种基于积分梯度的局部扰动算法LDIG(local disturbance algorithm based on integral gradient)。利用敏感链接的闭合子图确定扰动范围,根据扰动范围内链接的积分梯度迭代扰动链接,同时将链接预测对扰动图中敏感链接的预测结果作为扰动结束的判断依据。实验结果表明,LDIG算法的计算复杂度较低,适用于大规模社交网络的隐私保护,扰动链接的数量较少,提高了数据的效用性。
基金supported and funded by the Transport Area of Advance.The project IRIS is acknowledged for financial support.
文摘We propose pro-social control strategies for connected automated vehicles(CAVs)to mitigate jamming waves in mixed-autonomy multi-lane traffic,resulting from car-following dynamics of human-driven vehicles(HDVs).Different from existing studies,which focus mostly on ego vehicle objectives to control CAVs in an individualistic manner,we devise a pro-social control algorithm.The latter takes into account the objectives(i.e.,driving comfort and traffic efficiency)of both the ego vehicle and surrounding HDVs to improve smoothness of the entire observable traffic.Under a model predictive control(MPC)framework that uses acceleration and lane change sequences of CAVs as optimization variables,the problem of individualistic,altruistic,and pro-social control is formulated as a non-convex mixed-integer nonlinear program(MINLP)and relaxed to a convex quadratic program through converting the piece-wise-linear constraints due to the optimal velocity with relative velocity(OVRV)car-following model into linear constraints by introducing slack variables.Low-fidelity simulations using the OVRV model and high-fidelity simulations using PTV VISSIM simulator show that pro-social and altruistic control can provide significant performance gains over individualistic driving in terms of efficiency and comfort on both single-and multi-lane roads.
基金supported by the Russian Science Foundation(grant no.19-14-00119)The complex expeditions on Kolguev Island for wildfowl population monitoring were supported by Vogelschutz-Komitee and Conservation Bundesamt fur Naturschutz,BfN,(MEERESENTEN grant 3516821500).
文摘Behavioural lateralization,which reflects the functional specializations of the two brain hemispheres,is assumed to play an important role in cooperative intraspecific interactions.However,there are few studies focused on the lateralization in cooperative behaviours of individuals,especially in a natural setting.In the present study,we investigated Iateralized spatial interactions between the partners in life-long monogamous pairs.The male-female pairs of two geese species(barnacle,Branta leucopsis,and white-fronted,Anser albifrons geese),were observed during different stages of the annual cycle in a variety of conditions.In geese flocks,we recorded which visual hemifield(left/right)the following partner used to monitor the leading partner relevant to the type of behaviour and the disturbance factors.In a significant majority of pairs,the following bird viewed the leading partner with the left eye during routine behaviours such as resting and feeding in undisturbed conditions.This behavioural lateralization,implicating the right hemisphere processing,was consistent across the different aggregation sites and years of the study.In contrast,no significant bias was found in a variety of geese behaviours associated with enhanced disturbance(when alert on water,flying or fleeing away when disturbed,feeding during the hunting period,in urban area feeding and during moulting).We hypothesize that the increased demands for right hemisphere processing to deal with stressful and emergency situations may interfere with the manifestation of lateralization in social interactions.
