In response to the demand for short-range detection of anti-smoke environment interference by laser fuzes,this study proposes a smoke environment simulation of non-uniform continuous point source diffusion and investi...In response to the demand for short-range detection of anti-smoke environment interference by laser fuzes,this study proposes a smoke environment simulation of non-uniform continuous point source diffusion and investigates an experimental laboratory smoke environment using an ammonium chloride smoke agent.The particle size distribution,composition,and mass flow distribution of the smoke were studied.Based on a discrete phase model and a kεturbulence model,a numerical simulation was developed to model the smoke generation and diffusion processes of the smoke agent in a confined space.The temporal and spatial distribution characteristics of the smoke mass concentration,velocity,and temperature in the space after smoke generation were analyzed,and the motion law governing the smoke diffusion throughout the entire space was summarized.Combined with the experimental verification of the smoke environment laboratory,the results showed that the smoke plume changed from fan-shaped to umbrella-shaped during smoke generation,and then continued to spread around.Meanwhile,the mass concentration of smoke in the space decreased from the middle outward;the changes in temperature and velocity were small and stable.In the diffusion stage(after 900 s),the mass concentration of smoke above 0.8 m was relatively uniform across an area of smoke that was 12 m thick.The concentration decreased over time,following a consistent decreasing trend,and the attenuation was negligible in a very short time.Therefore,this system was suitable for conducting experimental research on laser fuzes in a smoke environment.Owing to the stability of the equipment and facilities,the setup could reproduce the same experimental smoke environment by artificially controlling the smoke emission of the smoke agent.Overall,this work provides a theoretical reference for subsequent research efforts regarding the construction of uniform smoke environments and evaluating laser transmission characteristics in smoky environments.展开更多
Owing to the wide range of applications in various fields,generative models have become increasingly popular.However,they do not handle spatio-temporal features well.Inspired by the recent advances in these models,thi...Owing to the wide range of applications in various fields,generative models have become increasingly popular.However,they do not handle spatio-temporal features well.Inspired by the recent advances in these models,this paper designs a distributed spatio-temporal generative adversarial network(STGAN-D)that,given some initial data and random noise,generates a consecutive sequence of spatio-temporal samples which have a logical relationship.This paper builds a spatio-temporal discriminator to distinguish whether the samples generated by the generator meet the requirements for time and space coherence,and builds a controller for distributed training of the network gradient updated to separate the model training and parameter updating,to improve the network training rate.The model is trained on the skeletal dataset and the traffic dataset.In contrast to traditional generative adversarial networks(GANs),the proposed STGAN-D can generate logically coherent samples with the corresponding spatial and temporal features while avoiding mode collapse.In addition,this paper shows that the proposed model can generate different styles of spatio-temporal samples given different random noise inputs,and the controller can improve the network training rate.This model will extend the potential range of applications of GANs to areas such as traffic information simulation and multiagent adversarial simulation.展开更多
蒸散发是水文循环和地表能量平衡的关键组成部分,对于水资源的有效管理、干旱情况的监测以及农业生产的优化均有着不可或缺的作用。选取红碱淖流域为研究区,基于Landsat8遥感数据,结合地表能量平衡系统(surface energy balance system,S...蒸散发是水文循环和地表能量平衡的关键组成部分,对于水资源的有效管理、干旱情况的监测以及农业生产的优化均有着不可或缺的作用。选取红碱淖流域为研究区,基于Landsat8遥感数据,结合地表能量平衡系统(surface energy balance system,SEBS)模型,估算了流域内2019年的6个日期的日蒸散发量,并对其进行了验证。通过对蒸散发的时空变化趋势和影响因素进行分析,获得结果表明:通过SEBS模型估算的日实际蒸散发量与通过Penman-Monteith(P-M)公式估算的潜在蒸散发量,以及气象站蒸发皿实际观测的蒸散发量的拟合优度R^(2)分别为0.84(P<0.01)、0.602(P<0.05),验证了SEBS模型在红碱淖流域的蒸散发量估算中具有较高的准确性和可靠性。红碱淖流域日蒸散发量呈现出明显的季节差异,夏季最高,春季次之,秋季再次,而冬季最低。流域东部红碱淖水体和流域西部查干淖尔及其周边区域的蒸散发量相对较高。流域中部蒸散发量相对较低。不同的土地利用类型中,水体的蒸散发量最高,其次是林地、耕地、建设用地、草地,最低的是未利用地。气象因素中,气温、气压和日照时数是主要影响因素,分别与蒸散发量呈显著正相关(r=0.847,P<0.05)、负相关(r=-0.840,P<0.05)和正相关(r=0.801,P<0.05),而相对湿度和风速与蒸散发量相关性较弱。展开更多
基金the Central University Special Funding for Basic Scientific Research(Grant No.30918012201)the Foundation of JWKJW Field(Grant 2020-JCJQ-JJ-392)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX20_0315).
文摘In response to the demand for short-range detection of anti-smoke environment interference by laser fuzes,this study proposes a smoke environment simulation of non-uniform continuous point source diffusion and investigates an experimental laboratory smoke environment using an ammonium chloride smoke agent.The particle size distribution,composition,and mass flow distribution of the smoke were studied.Based on a discrete phase model and a kεturbulence model,a numerical simulation was developed to model the smoke generation and diffusion processes of the smoke agent in a confined space.The temporal and spatial distribution characteristics of the smoke mass concentration,velocity,and temperature in the space after smoke generation were analyzed,and the motion law governing the smoke diffusion throughout the entire space was summarized.Combined with the experimental verification of the smoke environment laboratory,the results showed that the smoke plume changed from fan-shaped to umbrella-shaped during smoke generation,and then continued to spread around.Meanwhile,the mass concentration of smoke in the space decreased from the middle outward;the changes in temperature and velocity were small and stable.In the diffusion stage(after 900 s),the mass concentration of smoke above 0.8 m was relatively uniform across an area of smoke that was 12 m thick.The concentration decreased over time,following a consistent decreasing trend,and the attenuation was negligible in a very short time.Therefore,this system was suitable for conducting experimental research on laser fuzes in a smoke environment.Owing to the stability of the equipment and facilities,the setup could reproduce the same experimental smoke environment by artificially controlling the smoke emission of the smoke agent.Overall,this work provides a theoretical reference for subsequent research efforts regarding the construction of uniform smoke environments and evaluating laser transmission characteristics in smoky environments.
基金the National Natural Science Foundation of China(61573285).
文摘Owing to the wide range of applications in various fields,generative models have become increasingly popular.However,they do not handle spatio-temporal features well.Inspired by the recent advances in these models,this paper designs a distributed spatio-temporal generative adversarial network(STGAN-D)that,given some initial data and random noise,generates a consecutive sequence of spatio-temporal samples which have a logical relationship.This paper builds a spatio-temporal discriminator to distinguish whether the samples generated by the generator meet the requirements for time and space coherence,and builds a controller for distributed training of the network gradient updated to separate the model training and parameter updating,to improve the network training rate.The model is trained on the skeletal dataset and the traffic dataset.In contrast to traditional generative adversarial networks(GANs),the proposed STGAN-D can generate logically coherent samples with the corresponding spatial and temporal features while avoiding mode collapse.In addition,this paper shows that the proposed model can generate different styles of spatio-temporal samples given different random noise inputs,and the controller can improve the network training rate.This model will extend the potential range of applications of GANs to areas such as traffic information simulation and multiagent adversarial simulation.
文摘蒸散发是水文循环和地表能量平衡的关键组成部分,对于水资源的有效管理、干旱情况的监测以及农业生产的优化均有着不可或缺的作用。选取红碱淖流域为研究区,基于Landsat8遥感数据,结合地表能量平衡系统(surface energy balance system,SEBS)模型,估算了流域内2019年的6个日期的日蒸散发量,并对其进行了验证。通过对蒸散发的时空变化趋势和影响因素进行分析,获得结果表明:通过SEBS模型估算的日实际蒸散发量与通过Penman-Monteith(P-M)公式估算的潜在蒸散发量,以及气象站蒸发皿实际观测的蒸散发量的拟合优度R^(2)分别为0.84(P<0.01)、0.602(P<0.05),验证了SEBS模型在红碱淖流域的蒸散发量估算中具有较高的准确性和可靠性。红碱淖流域日蒸散发量呈现出明显的季节差异,夏季最高,春季次之,秋季再次,而冬季最低。流域东部红碱淖水体和流域西部查干淖尔及其周边区域的蒸散发量相对较高。流域中部蒸散发量相对较低。不同的土地利用类型中,水体的蒸散发量最高,其次是林地、耕地、建设用地、草地,最低的是未利用地。气象因素中,气温、气压和日照时数是主要影响因素,分别与蒸散发量呈显著正相关(r=0.847,P<0.05)、负相关(r=-0.840,P<0.05)和正相关(r=0.801,P<0.05),而相对湿度和风速与蒸散发量相关性较弱。
