In this paper we propose a two-layer emergent model for scalable swarm system. The first layer describes the indi-vidual flocking behavior to the local goal position (the center of minimal circumcircle decided by the ...In this paper we propose a two-layer emergent model for scalable swarm system. The first layer describes the indi-vidual flocking behavior to the local goal position (the center of minimal circumcircle decided by the neighbors in the positive visual set of individuals) resulting from the individual motion to one or two farthest neighbors in its positive visual set; the second layer describes the emergent aggregating swarm behavior resulting from the individual motion to its local goal position. The scale of the swarm will not be limited because only local individual information is used for modelling in the two-layer topology. We study the stability properties of the swarm emergent behavior based on Lyapunov stability theory. Simulations showed that the swarm system can converge to goal regions while maintaining cohesiveness.展开更多
A microscale air pollutant dispersion model system is developed for emergency response purposes. The model includes a diagnostic wind field model to simulate the wind field and a random-walk air pollutant dispersion m...A microscale air pollutant dispersion model system is developed for emergency response purposes. The model includes a diagnostic wind field model to simulate the wind field and a random-walk air pollutant dispersion model to simulate the pollutant concentration through consideration of the influence of urban buildings. Numerical experiments are designed to evaluate the model＇s performance, using CEDVAL （Compilation of Experimental Data for Validation of Microscale Disper- sion Models） wind tunnel experiment data, including wind fields and air pollutant dispersion around a single building. The results show that the wind model can reproduce the vortexes triggered by urban buildings and the dispersion model simulates the pollutant concentration around buildings well. Typically, the simulation errors come from the determination of the key zones around a building or building cluster. This model has the potential for multiple applications; for example, the prediction of air pollutant dispersion and the evaluation of environmental impacts in emergency situations; urban planning scenarios; and the assessment of microscale air quality in urban areas.展开更多
The simulation performance over complex building clusters of a wind simulation model（Wind Information Field Fast Analysis model, WIFFA） in a micro-scale air pollutant dispersion model system（Urban Microscale Air Po...The simulation performance over complex building clusters of a wind simulation model（Wind Information Field Fast Analysis model, WIFFA） in a micro-scale air pollutant dispersion model system（Urban Microscale Air Pollution dispersion Simulation model, UMAPS） is evaluated using various wind tunnel experimental data including the CEDVAL（Compilation of Experimental Data for Validation of Micro-Scale Dispersion Models） wind tunnel experiment data and the NJU-FZ experiment data（Nanjing University-Fang Zhuang neighborhood wind tunnel experiment data）. The results show that the wind model can reproduce the vortexes triggered by urban buildings well, and the flow patterns in urban street canyons and building clusters can also be represented. Due to the complex shapes of buildings and their distributions, the simulation deviations/discrepancies from the measurements are usually caused by the simplification of the building shapes and the determination of the key zone sizes. The computational efficiencies of different cases are also discussed in this paper. The model has a high computational efficiency compared to traditional numerical models that solve the Navier–Stokes equations, and can produce very high-resolution（1–5 m） wind fields of a complex neighborhood scale urban building canopy（～ 1 km ×1km） in less than 3 min when run on a personal computer.展开更多
This study examines how demographic factors shape engagement with virtual cultural communities and awareness of emerging economic models.Using survey data from 202 participants,descriptive statistics,independent sampl...This study examines how demographic factors shape engagement with virtual cultural communities and awareness of emerging economic models.Using survey data from 202 participants,descriptive statistics,independent samples t-tests,and One-way Analysis of Variance(ANOVA)with Least Significant Difference(LSD)post-hoc analyses revealed significant influences of age,education,and occupation.No significant gender differences were found.Individuals aged 26-45 demonstrated higher virtual community participation(F=3.439,p=0.01)and emerging model awareness(F=2.834,p=0.026)than younger cohorts(18-25 years and below).Respondents with postgraduate education exhibited superior understanding of emerging economic models(F=3.296,p=0.022)and their nexus with cultural values(F=6.196,p<0.001)compared to those with lower educational attainment.Significant occupational variations existed in virtual participation(F=4.001,p=0.008)and economic model awareness(F=5.611,p=0.001),with enterprise employees and civil servants scoring higher than students and freelancers.These findings underscore the critical roles of life stage,educational investment,and professional context in shaping digital cultural behaviors and economic cognition,offering valuable insights for platform design,educational strategies,and policy development in the digital cultural economy.展开更多
Introduction: Disaster management can face to emergency situation without any pre-sign and even if it has forecast they can meet the requirements of improvisation making their decision. Improvisation can be taken at a...Introduction: Disaster management can face to emergency situation without any pre-sign and even if it has forecast they can meet the requirements of improvisation making their decision. Improvisation can be taken at any level of the management (strategic, operational and tactical) but at tactical level the time press is certainly the biggest problem. This article focuses on tactical level and shows some method to compensate time press. Method: Author studied relevant literatures and used own ex-perience as a firefighting manager. Other studies made by the author previously were also used. Results: Without time press disaster managers can use analytical thinking but in case of time press they must prefer critical thinking, satisfactory procedures or management by exceptions but creativity and heuristics are also used in their decision. Author created a complex model of decision making in emergency: building on prac-tical experience the above mechanisms together with the internal triggers hold as pillars the recognition-primed decisions on which locate the principals of disaster man-agement.展开更多
A hydraulic model-based emergency schedul- ing Decision Support System （DSS） is designed to eliminate the impact of sudden contamination incidents occurring upstream in raw water supply systems with multiple sources...A hydraulic model-based emergency schedul- ing Decision Support System （DSS） is designed to eliminate the impact of sudden contamination incidents occurring upstream in raw water supply systems with multiple sources. The DSS consists of four functional modules, including water quality prediction, system safety assessment, emergency strategy inference and scheduling optimization. The work flow of the DSS is as follows. First, the water quality variations on specific cross-sections are calculated given the pollution information. Next, a comprehensive evaluation on the safety of the current system is conducted using the outputs in the first module. This will assist in the assessment of whether the system is in danger of failure, taking both the impact of pollution and system capacity into account. If there is a severe impact of contamination on the reliability of the system, a fuzzy logic based inference module is employed to generate reason- able strategies including technical measures. Otherwise, a Genetic Algorithm （GA）-based optimization model will be used to find the least-cost scheduling plan. The proposed DSS has been applied to a coastal city in South China during a saline tide period as validation. Through scenario analysis, it is demonstrated that this DSS tool is instrumental in emergency scheduling for the water company to quickly and effectively respond to sudden contamination incidents.展开更多
基金Project (No. 60574088) supported by the National Natural ScienceFoundation of China
文摘In this paper we propose a two-layer emergent model for scalable swarm system. The first layer describes the indi-vidual flocking behavior to the local goal position (the center of minimal circumcircle decided by the neighbors in the positive visual set of individuals) resulting from the individual motion to one or two farthest neighbors in its positive visual set; the second layer describes the emergent aggregating swarm behavior resulting from the individual motion to its local goal position. The scale of the swarm will not be limited because only local individual information is used for modelling in the two-layer topology. We study the stability properties of the swarm emergent behavior based on Lyapunov stability theory. Simulations showed that the swarm system can converge to goal regions while maintaining cohesiveness.
基金supported by the National Natural Science Foundation of China (Grant No. 41375014)the National Basic Research Program of China (Grant No. 2011CB 952002)Jiangsu Collaborative Innovation Center for Climate Change, China
文摘A microscale air pollutant dispersion model system is developed for emergency response purposes. The model includes a diagnostic wind field model to simulate the wind field and a random-walk air pollutant dispersion model to simulate the pollutant concentration through consideration of the influence of urban buildings. Numerical experiments are designed to evaluate the model＇s performance, using CEDVAL （Compilation of Experimental Data for Validation of Microscale Disper- sion Models） wind tunnel experiment data, including wind fields and air pollutant dispersion around a single building. The results show that the wind model can reproduce the vortexes triggered by urban buildings and the dispersion model simulates the pollutant concentration around buildings well. Typically, the simulation errors come from the determination of the key zones around a building or building cluster. This model has the potential for multiple applications; for example, the prediction of air pollutant dispersion and the evaluation of environmental impacts in emergency situations; urban planning scenarios; and the assessment of microscale air quality in urban areas.
基金supported by the China Special Fund for Meteorological Research in the Public Interest(Grant No.GYHY201106049)the National Natural Science Foundation of China(Grant Nos.51538005 and 41375014)the Jiangsu Collaborative Innovation Center for Climate Change,China
文摘The simulation performance over complex building clusters of a wind simulation model（Wind Information Field Fast Analysis model, WIFFA） in a micro-scale air pollutant dispersion model system（Urban Microscale Air Pollution dispersion Simulation model, UMAPS） is evaluated using various wind tunnel experimental data including the CEDVAL（Compilation of Experimental Data for Validation of Micro-Scale Dispersion Models） wind tunnel experiment data and the NJU-FZ experiment data（Nanjing University-Fang Zhuang neighborhood wind tunnel experiment data）. The results show that the wind model can reproduce the vortexes triggered by urban buildings well, and the flow patterns in urban street canyons and building clusters can also be represented. Due to the complex shapes of buildings and their distributions, the simulation deviations/discrepancies from the measurements are usually caused by the simplification of the building shapes and the determination of the key zone sizes. The computational efficiencies of different cases are also discussed in this paper. The model has a high computational efficiency compared to traditional numerical models that solve the Navier–Stokes equations, and can produce very high-resolution（1–5 m） wind fields of a complex neighborhood scale urban building canopy（～ 1 km ×1km） in less than 3 min when run on a personal computer.
文摘This study examines how demographic factors shape engagement with virtual cultural communities and awareness of emerging economic models.Using survey data from 202 participants,descriptive statistics,independent samples t-tests,and One-way Analysis of Variance(ANOVA)with Least Significant Difference(LSD)post-hoc analyses revealed significant influences of age,education,and occupation.No significant gender differences were found.Individuals aged 26-45 demonstrated higher virtual community participation(F=3.439,p=0.01)and emerging model awareness(F=2.834,p=0.026)than younger cohorts(18-25 years and below).Respondents with postgraduate education exhibited superior understanding of emerging economic models(F=3.296,p=0.022)and their nexus with cultural values(F=6.196,p<0.001)compared to those with lower educational attainment.Significant occupational variations existed in virtual participation(F=4.001,p=0.008)and economic model awareness(F=5.611,p=0.001),with enterprise employees and civil servants scoring higher than students and freelancers.These findings underscore the critical roles of life stage,educational investment,and professional context in shaping digital cultural behaviors and economic cognition,offering valuable insights for platform design,educational strategies,and policy development in the digital cultural economy.
文摘Introduction: Disaster management can face to emergency situation without any pre-sign and even if it has forecast they can meet the requirements of improvisation making their decision. Improvisation can be taken at any level of the management (strategic, operational and tactical) but at tactical level the time press is certainly the biggest problem. This article focuses on tactical level and shows some method to compensate time press. Method: Author studied relevant literatures and used own ex-perience as a firefighting manager. Other studies made by the author previously were also used. Results: Without time press disaster managers can use analytical thinking but in case of time press they must prefer critical thinking, satisfactory procedures or management by exceptions but creativity and heuristics are also used in their decision. Author created a complex model of decision making in emergency: building on prac-tical experience the above mechanisms together with the internal triggers hold as pillars the recognition-primed decisions on which locate the principals of disaster man-agement.
文摘A hydraulic model-based emergency schedul- ing Decision Support System （DSS） is designed to eliminate the impact of sudden contamination incidents occurring upstream in raw water supply systems with multiple sources. The DSS consists of four functional modules, including water quality prediction, system safety assessment, emergency strategy inference and scheduling optimization. The work flow of the DSS is as follows. First, the water quality variations on specific cross-sections are calculated given the pollution information. Next, a comprehensive evaluation on the safety of the current system is conducted using the outputs in the first module. This will assist in the assessment of whether the system is in danger of failure, taking both the impact of pollution and system capacity into account. If there is a severe impact of contamination on the reliability of the system, a fuzzy logic based inference module is employed to generate reason- able strategies including technical measures. Otherwise, a Genetic Algorithm （GA）-based optimization model will be used to find the least-cost scheduling plan. The proposed DSS has been applied to a coastal city in South China during a saline tide period as validation. Through scenario analysis, it is demonstrated that this DSS tool is instrumental in emergency scheduling for the water company to quickly and effectively respond to sudden contamination incidents.
