Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral response.Recent studies have shown that brain-derived neurotrophic factor expression in stressed mice ...Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral response.Recent studies have shown that brain-derived neurotrophic factor expression in stressed mice is brain region–specific,particularly involving the corticolimbic system,including the ventral tegmental area,nucleus accumbens,prefrontal cortex,amygdala,and hippocampus.Determining how brain-derived neurotrophic factor participates in stress processing in different brain regions will deepen our understanding of social stress psychopathology.In this review,we discuss the expression and regulation of brain-derived neurotrophic factor in stress-sensitive brain regions closely related to the pathophysiology of depression.We focused on associated molecular pathways and neural circuits,with special attention to the brain-derived neurotrophic factor–tropomyosin receptor kinase B signaling pathway and the ventral tegmental area–nucleus accumbens dopamine circuit.We determined that stress-induced alterations in brain-derived neurotrophic factor levels are likely related to the nature,severity,and duration of stress,especially in the above-mentioned brain regions of the corticolimbic system.Therefore,BDNF might be a biological indicator regulating stress-related processes in various brain regions.展开更多
An accurate assessment of the evacuation efficiency in case of disasters is of vital importance to the safety design of buildings and street blocks.Hazard sources not only physically but psychologically affect the ped...An accurate assessment of the evacuation efficiency in case of disasters is of vital importance to the safety design of buildings and street blocks.Hazard sources not only physically but psychologically affect the pedestrians,which may further alter their behavioral patterns.This effect is especially significant in narrow spaces,such as corridors and alleys.This study aims to integrate a non-spreading hazard source into the social force model following the results from a previous experiment and simulation,and to simulate unidirectional pedestrian flows over various crowd densities and clarity–intensity properties of the hazard source.The integration include a virtual repulsion force from the hazard source and a decay on the social force term.The simulations reveal(i)that the hazard source creates virtual bottlenecks that suppress the flow,(ii)that the inter-pedestrian push forms a stabilisation phase on the flow-density curve within medium-to-high densities,and(iii)that the pedestrians are prone to a less orderly and stable pattern of movement in low clarity–intensity scenarios,possibly with lateral collisions passing the hazard source.展开更多
The subway is the primary travel tool for urban residents in China. Due to the complex structure of the subway and high personnel density in rush hours, subway evacuation capacity is critical. The subway evacuation mo...The subway is the primary travel tool for urban residents in China. Due to the complex structure of the subway and high personnel density in rush hours, subway evacuation capacity is critical. The subway evacuation model is explored in this work by combining the improved social force model with the view radius using the Vicsek model. The pedestrians are divided into two categories based on different force models. The first category is sensitive pedestrians who have normal responses to emergency signs. The second category is insensitive pedestrians. By simulating different proportions of the insensitive pedestrians, we find that the escape time is directly proportional to the number of insensitive pedestrians and inversely proportional to the view radius. However, when the view radius is large enough, the escape time does not change significantly, and the evacuation of people in a small view radius environment tends to be integrated. With the improvement of view radius conditions, the escape time changes more obviously with the proportion of insensitive pedestrians. A new emergency sign layout is proposed, and the simulations show that the proposed layout can effectively reduce the escape time in a small view radius environment. However, the evacuation effect of the new escape sign layout on the large view radius environment is not apparent. In this case, the exit setting emerges as an additional factor affecting the escape time.展开更多
In the process of crowd movement,pedestrians are often affected by their neighbors.In order to describe the consistency of adjacent individuals and collectivity of a group,this paper learns from the rules of the flock...In the process of crowd movement,pedestrians are often affected by their neighbors.In order to describe the consistency of adjacent individuals and collectivity of a group,this paper learns from the rules of the flocking behavior,such as segregation,alignment and cohesion,and proposes a method for crowd motion simulation based on the Boids model and social force model.Firstly,the perception area of individuals is divided into zone of segregation,alignment and cohesion.Secondly,the interactive force among individuals is calculated based upon the zone information,velocity vector and the group information.The interactive force among individuals is the synthesis of three forces:the repulsion force to avoid collisions,the alignment force to keep consistent with the velocity direction,and the attractive force to get close to the members of group.In segregation and alignment areas,the repulsion force and alignment force among pedestrians are limited by visual field factors.Finally,the interactive force among individuals,the driving force of destination and the repulsion force of obstacles work together to drive the behavior of crowd motion.The simulation results show that the proposed method can not only effectively simulate the interactive behavior between adjacent individuals but also the collective behavior of group.展开更多
With the rapid development of the UHV power grid, evaluation of the economic and social benefits of the UHV power grid is conducive to guiding the planning and construction of UHV power grid. At present economic benef...With the rapid development of the UHV power grid, evaluation of the economic and social benefits of the UHV power grid is conducive to guiding the planning and construction of UHV power grid. At present economic benefit evaluation system of the UHV power grid is driving to maturity stage on the whole at home and abroad, but it invariably tends to regard social benefits as part of economic benefits, without evaluating social benefit separately. The social benefit evaluation model of UHV power grid is built in case of sufficient investigation. The differentials between social benefit and social cost are calculated respectively by three kinds of solutions according to the constructed social cost evaluation index system and social benefits evaluation index system, conclusion that UHV power grid transmission has better social benefits can be reached by contrastively analyzing the social three kinds of solutions corresponding to benefits. At last, the evaluation model and method are verified and analyzed through the analysis of engineering projects.展开更多
OBJECTIVE To explore the pathogenesis of depression according to the LC-MS/MS-based metabolomics in the mouse model which exhibits social avoidance state induced by the chronic social defeat stress model(CSDS).METHODS...OBJECTIVE To explore the pathogenesis of depression according to the LC-MS/MS-based metabolomics in the mouse model which exhibits social avoidance state induced by the chronic social defeat stress model(CSDS).METHODS Twenty male C57BL/6N mice were randomly divided into control group and model group suffering CSDS,and the ICR retired breeder mice were used to attack the model group for 14 d of chronic social defeated stress.The open field test and source preference test were both used to observe depression-like behavior.Besides,the social interaction test is used to observe the social interaction state,especially.After the stress,the serum samples of mice were collected,and the changes of endogenous metabolites were analyzed by LC-MS metabolomics technology,and the pathway analysis of the differential metabolites was performed to explore the pathogenesis of the CSDS induced depressive-like mouse model.RESULTS After the stress of CSDS was completed,the mice in the model group showed a significant slowdown in body weight growth,a reduction in the source preference rate,and a significant reduction in the total distance and the number of rearing in the open field test.Distinctively,the social interaction rate is remarkably decreasing.There are 24 differential metabolites found in the serum of CSDS model mice.CONCLUSION The mouse who suffered CSDS stress would show depressive-like behavior.Based on the LC-MS/MS metabolomics,24 differential metabolites were found in the serum of CSDS model mice.The amino acid metabolism might be significant to the pathogenesis of the CSDS induced depressive-like mouse model.展开更多
As enterprises expand globally, the social value of their operations is assessed on the full range of their contribution to society. Enterprises must be profitable to succeed, but they also should strategically align ...As enterprises expand globally, the social value of their operations is assessed on the full range of their contribution to society. Enterprises must be profitable to succeed, but they also should strategically align their operations so far as feasible and sustainable in order to address related social needs. This alignment includes not only the beneficial design and quality of goods and services an enterprise produces, but also enhancing the beneficial effects that its full range of business processes, systems, and practices have on society. A comprehensive enterprise corporate social responsibility (CSR) audit is based on two comprehensive social systems models---one of society as a whole and another of the corporate organization. By juxtaposing these two models--which are mirror images of each other--an enterprise can identify various points where its activities intersect with relevant social needs and can configure its operations so far as feasible to alleviate pressing social issues. Using a comparative cost-benefit analysis, the enterprise determines which systems, processes, and activities need to configure or adapt in order to better address the societal needs that are most critical for its success. They may require the enterprise to re-design products or services, develop new activities or desist in others, or reconfigure processes or systems. Thus, enterprises must decide which options are most feasible in light of the societal benefit they are likely to produce. As creatures of society, enterprises have much to gain by strengthening civil society and addressing its most pressing needs whenever possible within the limits of its commercial mission. What action to take depends upon the firm's cost-benefit analysis.展开更多
With the penetration of the Internet, virtual groups have become more and more popular. The reliability and accuracy of interpersonal perception in the virtual environment is an intriguing issue. Using the Social rela...With the penetration of the Internet, virtual groups have become more and more popular. The reliability and accuracy of interpersonal perception in the virtual environment is an intriguing issue. Using the Social relations model (SRM) [1], this paper investigates interpersonal perception in virtual groups from a multilevel perspective. In particular, it examines the following three areas: homophily, identification, and individual attraction, and explores how much of these directional and dyadic relational evaluations can be attributed to the effect of the actor, the partner, and the relationship.展开更多
While achieving successes,the neoliberalist economic development model hasalso given rise to a series of grave problems,especially problem of social injusticeand polarization,which have begun to threaten Latin America...While achieving successes,the neoliberalist economic development model hasalso given rise to a series of grave problems,especially problem of social injusticeand polarization,which have begun to threaten Latin America’s social security andstability.展开更多
The previous studies on detection of communities on complex networks were focused on nondirected graphs, such as Neural Networks, social networks, social interrelations, the contagion of diseases, and bibliographies. ...The previous studies on detection of communities on complex networks were focused on nondirected graphs, such as Neural Networks, social networks, social interrelations, the contagion of diseases, and bibliographies. However, there are also other problems whose modeling entails obtaining a weakly connected directed graph such as the student access to the university, the public transport networks, or trophic chains. Those cases deserve particularized study with an analysis and the resolution adjusted to them. Additionally, this is a challenge, since the existing algorithms in most of the cases were originally designed for non-directed graphs or symmetrical and regular graphs. Our proposal is a Benchmark Generator of Weakly Connected Directed Graphs whose properties can be defined by the end-users according to their necessities. The source code of the generators described in this article is available in GitHub under the GNU license.展开更多
Background:Social accountability(SA)comprises a set of mechanisms aiming to,on the one hand,enable users to raise their concerns about the health services provided to them(voice),and to hold health providers(HPs)accou...Background:Social accountability(SA)comprises a set of mechanisms aiming to,on the one hand,enable users to raise their concerns about the health services provided to them(voice),and to hold health providers(HPs)accountable for actions and decisions related to the health service provision.On the other hand,they aim to facilitate HPs to take into account users’needs and expectations in providing care.This article describes the development of a SA intervention that aims to improve health services responsiveness in two health zones in the Democratic Republic of the Congo.Methods:Beneficiaries including men,women,community health workers(CHWs),representatives of the health sector and local authorities were purposively selected and involved in an advisory process using the Dialogue Model in the two health zones:(1)Eight focus group discussions(FGDs)were organized separately during consultation aimed at sharing and discussing results from the situation analysis,and collecting suggestions for improvement,(2)Representatives of participants in previous FGDs were involved in dialogue meetings for prioritizing and integrating suggestions from FGDs,and(3)the integrated suggestions were discussed by research partners and set as intervention components.All the processes were audio-taped,transcribed and analysed using inductive content analysis.Results:Overall there were 121 participants involved in the process,51 were female.They provided 48 suggestions.Their suggestions were integrated into six intervention components during dialogue meetings:(1)use CHWs and a health committee for collecting and transmitting community concerns about health services,(2)build the capacity of the community in terms of knowledge and information,(3)involve community leaders through dialogue meetings,(4)improve the attitude of HPs towards voice and the management of voice at health facility level,(5)involve the health service supervisors in community participation and;(6)use other existing interventions.These components were then articulated into three intervention components during programming to:create a formal voice system,introduce dialogue meetings improving enforceability and answerability,and enhance the health providers’responsiveness.Conclusions:The use of the Dialogue Model,a participatory process,allowed beneficiaries to be involved with other community stakeholders having different perspectives and types of knowledge in an advisory process and to articulate their suggestions on a combination of SA intervention components,specific for the two health zones contexts.展开更多
The pedestrians can only avoid collisions passively under the action of forces during simulations using the social force model, which may lead to unnatural behaviors. This paper proposes an optimization-based model fo...The pedestrians can only avoid collisions passively under the action of forces during simulations using the social force model, which may lead to unnatural behaviors. This paper proposes an optimization-based model for the avoidance of collisions, where the social repulsive force is removed in favor of a search for the quickest path to destination in the pedestrian's vision field. In this way, the behaviors of pedestrians are governed by changing their desired walking direction and desired speed. By combining the critical factors of pedestrian movement, such as positions of the exit and obstacles and velocities of the neighbors, the choice of desired velocity has been rendered to a discrete optimization problem. Therefore,it is the self-driven force that leads pedestrians to a free path rather than the repulsive force, which means the pedestrians can actively avoid collisions. The new model is verified by comparing with the fundamental diagram and actual data. The simulation results of individual avoidance trajectories and crowd avoidance behaviors demonstrate the reasonability of the proposed model.展开更多
With the development of urban rail transit, ensuring the safe evacuation of pedestrians at subway stations has become an important issue in the case of an emergency such as a fire. This paper chooses the platform of l...With the development of urban rail transit, ensuring the safe evacuation of pedestrians at subway stations has become an important issue in the case of an emergency such as a fire. This paper chooses the platform of line 4 at the Beijing Xu- anwumen subway station to study the emergency evacuation process under fire. Based on the established platform, effects of the fire dynamics, different initial pedestrian densities, and positions of fire on evacuation are investigated. According to simulation results, it is found that the fire increases the air temperature and the smoke density, and decreases pedestrians'- visibility and walking velocity. Also, there is a critical initial density at the platform if achieving a safe evacuation within the required 6 minutes. Furthermore, different positions of fire set in this paper have little difference on crowd evacuation if the fire is not large enough. The suggestions provided in this paper are helpful for the subway operators to prevent major casualties.展开更多
This paper presents a model for simulating crowd evacuation and investigates three widely recognized problems. For the space continuity problem, this paper presents two computation algorithms: one uses grid space to ...This paper presents a model for simulating crowd evacuation and investigates three widely recognized problems. For the space continuity problem, this paper presents two computation algorithms: one uses grid space to evaluate the coordinates of the obstacle's bounding box and the other employs the geometry rule to establish individual evacuation routes. For the problem of collision, avoidance, and excess among the individuals, this paper computes the generalized force and friction force and then modifies the direction of march to obtain a speed model based on the crowd density and real time speed. For the exit selection problem, this paper establishes a method of selecting the exits by combining the exit's crowd state with the individuals. Finally, a particle system is used to simulate the behavior of crowd evacuation and produces useful test results.展开更多
Pedestrian's road-crossing model is the key part of micro-simulation for mixed traffic at signalized intersection.To reproduce the crossing behavior of pedestrians,the microscopic behaviors of the pedestrians pass...Pedestrian's road-crossing model is the key part of micro-simulation for mixed traffic at signalized intersection.To reproduce the crossing behavior of pedestrians,the microscopic behaviors of the pedestrians passing through the crosswalk at signalized intersection were analyzed.A pedestrian's decision making model based on gap acceptance theory was proposed.Based on the field data at three typical intersections in Beijing,China,the critical gaps and lags of pedestrians were calibrated.In addition,considering pedestrian's required space,a modification of the social force model that consists of a self-deceleration mechanism prevents a simulated pedestrian from continuously pushing over other pedestrians,making the simulation more realistic.After the simple change,the modified social force model is able to reproduce the fundamental diagram of pedestrian flows for densities less than 3.5 m-2 as reported in the literature.展开更多
The bottleneck effect on bidirectional crowd dynamics is of great theoretical and practical significance, especially for the designing of corridors in public places, such as subway stations or airports. Based on the f...The bottleneck effect on bidirectional crowd dynamics is of great theoretical and practical significance, especially for the designing of corridors in public places, such as subway stations or airports. Based on the famous social force model, this paper investigates the bottleneck effects on the free flow dynamics and breakdown phenomenon under different scenarios, in which different corridor shapes and inflow ratios are considered simultaneously. Numerical simulation finds an interesting self-organization phenomenon in the bidirectional flow, a typical characteristic of such a phenomenon is called lane formation, and the existence of which is independent of the corridor's shape and inflow rate. However, the pattern of the lane formed by pedestrian flow is related to the corridor's shape, and the free flow efficiency has close relationship with the inflow rate. Specifically, breakdown phenomenon occurs when inflows from both sides of the corridor are large enough, which mostly originates from the bottleneck and then gradually spreads to the other regions. Simulation results further indicate that the leaving efficiency becomes low as breakdown occurs, and the degree of congestion is proportional to the magnitude of inflow. The findings presented in this paper match well with some of our daily observations, hence it is possible to use them to provide us with theoretical suggestions in design of infrastructures.展开更多
Under the background of Covid-19 sweeping the world,safe and reasonable passenger flow management strategy in subway stations is an effective means to prevent the spread of virus.Based on the social force model and th...Under the background of Covid-19 sweeping the world,safe and reasonable passenger flow management strategy in subway stations is an effective means to prevent the spread of virus.Based on the social force model and the minimum cost model,the movement and path selection behavior of passengers in the subway station are modeled,and a strategy for passenger flow management to maintain a safe social distance is put forward.Take Qingdao Jinggangshan Road subway station of China as the simulation scene,the validity of the simulation model is verified by comparing the measured value and simulation value of the time required for passengers from getting off the train to the ticket gate.Simulation results indicate that controlling the time interval between incoming passengers at the entrance can effectively control the social distance between passengers and reduce the risk of epidemic infection.By comparing the evacuation process of passengers under different initial densities,it is found that the greater the initial density of passengers is,the longer the passengers are at risk social distance.In the process of passenger emergency evacuation,the stairs/escalators and ticket gates are bottleneck areas with high concentration of passenger density,which should be strictly disinfected many times on the basis of strictly checking the health code of incoming passengers and controlling the arrival time interval.The simulation results of this paper verify the harmfulness of passenger emergency evacuation without protective measures,and provide theoretical support for the operation and management of subway station under the epidemic situation.展开更多
This paper focuses on the simulation analysis of stripe formation and dynamic features of intersecting pedestrian flows.The intersecting flows consist of two streams of pedestrians and each pedestrian stream has a des...This paper focuses on the simulation analysis of stripe formation and dynamic features of intersecting pedestrian flows.The intersecting flows consist of two streams of pedestrians and each pedestrian stream has a desired walking direction.The model adopted in the simulations is the social force model, which can reproduce the self-organization phenomena successfully. Three scenarios of different cross angles are established. The simulations confirm the empirical observations that there is a stripe formation when two streams of pedestrians intersect and the direction of the stripes is perpendicular to the sum of the directional vectors of the two streams. It can be concluded from the numerical simulation results that smaller cross angle results in higher mean speed and lower level of speed fluctuation. Moreover, the detailed pictures of pedestrians' moving behavior at intersections are given as well.展开更多
The paper builds up a cost-benefit measuring model of green products in manufacturing industry throughout its full life cycle, which can quantify green products' cost and benefit completely and correctly under the ci...The paper builds up a cost-benefit measuring model of green products in manufacturing industry throughout its full life cycle, which can quantify green products' cost and benefit completely and correctly under the circumstance of satisfying enterprise, customer, environment and society. It also puts forth an operable method to estimate social benefit by opportunity cost and establishes a profit maximization-programming model. The model can be applied to justify whether some kinds of green products should be developed and produced.展开更多
Analysis of dynamic features of pedestrian flows is one of the most exciting topics in pedestrian dynamics. This paper focuses on the effect of homogeneity and heterogeneity in three parameters of the social force mod...Analysis of dynamic features of pedestrian flows is one of the most exciting topics in pedestrian dynamics. This paper focuses on the effect of homogeneity and heterogeneity in three parameters of the social force model, namely desired velocity, reaction time, and body size, on the moving dynamics of bidirectional pedestrian flows in the corridors. The speed and its deviation in free flows are investigated. Simulation results show that the homogeneous higher desired speed which is less than a critical threshold, shorter reaction time or smaller body size results in higher speed of flows. The free dynamics is more sensitive to the heterogeneity in desired speed than that in reaction time or in body size. In particular, an inner lane formation is observed in normal lanes. Furthermore, the breakdown probability and the start time of breakdown are focused on. This study reveals that the sizes of homogeneous desired speed, reaction time or body size play more important roles in affecting the breakdown than the heterogeneities in these three parameters do.展开更多
基金supported financially by the National Natural Science Foundation of China,No.82071272(to YZ).
文摘Brain-derived neurotrophic factor is a key factor in stress adaptation and avoidance of a social stress behavioral response.Recent studies have shown that brain-derived neurotrophic factor expression in stressed mice is brain region–specific,particularly involving the corticolimbic system,including the ventral tegmental area,nucleus accumbens,prefrontal cortex,amygdala,and hippocampus.Determining how brain-derived neurotrophic factor participates in stress processing in different brain regions will deepen our understanding of social stress psychopathology.In this review,we discuss the expression and regulation of brain-derived neurotrophic factor in stress-sensitive brain regions closely related to the pathophysiology of depression.We focused on associated molecular pathways and neural circuits,with special attention to the brain-derived neurotrophic factor–tropomyosin receptor kinase B signaling pathway and the ventral tegmental area–nucleus accumbens dopamine circuit.We determined that stress-induced alterations in brain-derived neurotrophic factor levels are likely related to the nature,severity,and duration of stress,especially in the above-mentioned brain regions of the corticolimbic system.Therefore,BDNF might be a biological indicator regulating stress-related processes in various brain regions.
基金Project supported by National Key Research and Development Program of China(Grant Nos.2022YFC3320800 and 2021YFC1523500)the National Natural Science Foundation of China(Grant Nos.71971126,71673163,72304165,72204136,and 72104123).
文摘An accurate assessment of the evacuation efficiency in case of disasters is of vital importance to the safety design of buildings and street blocks.Hazard sources not only physically but psychologically affect the pedestrians,which may further alter their behavioral patterns.This effect is especially significant in narrow spaces,such as corridors and alleys.This study aims to integrate a non-spreading hazard source into the social force model following the results from a previous experiment and simulation,and to simulate unidirectional pedestrian flows over various crowd densities and clarity–intensity properties of the hazard source.The integration include a virtual repulsion force from the hazard source and a decay on the social force term.The simulations reveal(i)that the hazard source creates virtual bottlenecks that suppress the flow,(ii)that the inter-pedestrian push forms a stabilisation phase on the flow-density curve within medium-to-high densities,and(iii)that the pedestrians are prone to a less orderly and stable pattern of movement in low clarity–intensity scenarios,possibly with lateral collisions passing the hazard source.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51874183 and 51874182)the National Key Research and Development Program of China (Grant No. 2018YFC0809300)。
文摘The subway is the primary travel tool for urban residents in China. Due to the complex structure of the subway and high personnel density in rush hours, subway evacuation capacity is critical. The subway evacuation model is explored in this work by combining the improved social force model with the view radius using the Vicsek model. The pedestrians are divided into two categories based on different force models. The first category is sensitive pedestrians who have normal responses to emergency signs. The second category is insensitive pedestrians. By simulating different proportions of the insensitive pedestrians, we find that the escape time is directly proportional to the number of insensitive pedestrians and inversely proportional to the view radius. However, when the view radius is large enough, the escape time does not change significantly, and the evacuation of people in a small view radius environment tends to be integrated. With the improvement of view radius conditions, the escape time changes more obviously with the proportion of insensitive pedestrians. A new emergency sign layout is proposed, and the simulations show that the proposed layout can effectively reduce the escape time in a small view radius environment. However, the evacuation effect of the new escape sign layout on the large view radius environment is not apparent. In this case, the exit setting emerges as an additional factor affecting the escape time.
文摘In the process of crowd movement,pedestrians are often affected by their neighbors.In order to describe the consistency of adjacent individuals and collectivity of a group,this paper learns from the rules of the flocking behavior,such as segregation,alignment and cohesion,and proposes a method for crowd motion simulation based on the Boids model and social force model.Firstly,the perception area of individuals is divided into zone of segregation,alignment and cohesion.Secondly,the interactive force among individuals is calculated based upon the zone information,velocity vector and the group information.The interactive force among individuals is the synthesis of three forces:the repulsion force to avoid collisions,the alignment force to keep consistent with the velocity direction,and the attractive force to get close to the members of group.In segregation and alignment areas,the repulsion force and alignment force among pedestrians are limited by visual field factors.Finally,the interactive force among individuals,the driving force of destination and the repulsion force of obstacles work together to drive the behavior of crowd motion.The simulation results show that the proposed method can not only effectively simulate the interactive behavior between adjacent individuals but also the collective behavior of group.
文摘With the rapid development of the UHV power grid, evaluation of the economic and social benefits of the UHV power grid is conducive to guiding the planning and construction of UHV power grid. At present economic benefit evaluation system of the UHV power grid is driving to maturity stage on the whole at home and abroad, but it invariably tends to regard social benefits as part of economic benefits, without evaluating social benefit separately. The social benefit evaluation model of UHV power grid is built in case of sufficient investigation. The differentials between social benefit and social cost are calculated respectively by three kinds of solutions according to the constructed social cost evaluation index system and social benefits evaluation index system, conclusion that UHV power grid transmission has better social benefits can be reached by contrastively analyzing the social three kinds of solutions corresponding to benefits. At last, the evaluation model and method are verified and analyzed through the analysis of engineering projects.
文摘OBJECTIVE To explore the pathogenesis of depression according to the LC-MS/MS-based metabolomics in the mouse model which exhibits social avoidance state induced by the chronic social defeat stress model(CSDS).METHODS Twenty male C57BL/6N mice were randomly divided into control group and model group suffering CSDS,and the ICR retired breeder mice were used to attack the model group for 14 d of chronic social defeated stress.The open field test and source preference test were both used to observe depression-like behavior.Besides,the social interaction test is used to observe the social interaction state,especially.After the stress,the serum samples of mice were collected,and the changes of endogenous metabolites were analyzed by LC-MS metabolomics technology,and the pathway analysis of the differential metabolites was performed to explore the pathogenesis of the CSDS induced depressive-like mouse model.RESULTS After the stress of CSDS was completed,the mice in the model group showed a significant slowdown in body weight growth,a reduction in the source preference rate,and a significant reduction in the total distance and the number of rearing in the open field test.Distinctively,the social interaction rate is remarkably decreasing.There are 24 differential metabolites found in the serum of CSDS model mice.CONCLUSION The mouse who suffered CSDS stress would show depressive-like behavior.Based on the LC-MS/MS metabolomics,24 differential metabolites were found in the serum of CSDS model mice.The amino acid metabolism might be significant to the pathogenesis of the CSDS induced depressive-like mouse model.
文摘As enterprises expand globally, the social value of their operations is assessed on the full range of their contribution to society. Enterprises must be profitable to succeed, but they also should strategically align their operations so far as feasible and sustainable in order to address related social needs. This alignment includes not only the beneficial design and quality of goods and services an enterprise produces, but also enhancing the beneficial effects that its full range of business processes, systems, and practices have on society. A comprehensive enterprise corporate social responsibility (CSR) audit is based on two comprehensive social systems models---one of society as a whole and another of the corporate organization. By juxtaposing these two models--which are mirror images of each other--an enterprise can identify various points where its activities intersect with relevant social needs and can configure its operations so far as feasible to alleviate pressing social issues. Using a comparative cost-benefit analysis, the enterprise determines which systems, processes, and activities need to configure or adapt in order to better address the societal needs that are most critical for its success. They may require the enterprise to re-design products or services, develop new activities or desist in others, or reconfigure processes or systems. Thus, enterprises must decide which options are most feasible in light of the societal benefit they are likely to produce. As creatures of society, enterprises have much to gain by strengthening civil society and addressing its most pressing needs whenever possible within the limits of its commercial mission. What action to take depends upon the firm's cost-benefit analysis.
文摘With the penetration of the Internet, virtual groups have become more and more popular. The reliability and accuracy of interpersonal perception in the virtual environment is an intriguing issue. Using the Social relations model (SRM) [1], this paper investigates interpersonal perception in virtual groups from a multilevel perspective. In particular, it examines the following three areas: homophily, identification, and individual attraction, and explores how much of these directional and dyadic relational evaluations can be attributed to the effect of the actor, the partner, and the relationship.
文摘While achieving successes,the neoliberalist economic development model hasalso given rise to a series of grave problems,especially problem of social injusticeand polarization,which have begun to threaten Latin America’s social security andstability.
基金supported by the Project“Complex Networks”from the Instituto Universitario de Matematica Multidisciplinar(IUMM)of the Universitat Politecnica de Valencia(UPV)[under Grant number(266500194)20170251-Complex-Networks-UPV]
文摘The previous studies on detection of communities on complex networks were focused on nondirected graphs, such as Neural Networks, social networks, social interrelations, the contagion of diseases, and bibliographies. However, there are also other problems whose modeling entails obtaining a weakly connected directed graph such as the student access to the university, the public transport networks, or trophic chains. Those cases deserve particularized study with an analysis and the resolution adjusted to them. Additionally, this is a challenge, since the existing algorithms in most of the cases were originally designed for non-directed graphs or symmetrical and regular graphs. Our proposal is a Benchmark Generator of Weakly Connected Directed Graphs whose properties can be defined by the end-users according to their necessities. The source code of the generators described in this article is available in GitHub under the GNU license.
基金support of the WOTRO program and its improving maternal health services responsiveness and performances through social accountability mechanisms in the DRC and Burundi(IMCH).
文摘Background:Social accountability(SA)comprises a set of mechanisms aiming to,on the one hand,enable users to raise their concerns about the health services provided to them(voice),and to hold health providers(HPs)accountable for actions and decisions related to the health service provision.On the other hand,they aim to facilitate HPs to take into account users’needs and expectations in providing care.This article describes the development of a SA intervention that aims to improve health services responsiveness in two health zones in the Democratic Republic of the Congo.Methods:Beneficiaries including men,women,community health workers(CHWs),representatives of the health sector and local authorities were purposively selected and involved in an advisory process using the Dialogue Model in the two health zones:(1)Eight focus group discussions(FGDs)were organized separately during consultation aimed at sharing and discussing results from the situation analysis,and collecting suggestions for improvement,(2)Representatives of participants in previous FGDs were involved in dialogue meetings for prioritizing and integrating suggestions from FGDs,and(3)the integrated suggestions were discussed by research partners and set as intervention components.All the processes were audio-taped,transcribed and analysed using inductive content analysis.Results:Overall there were 121 participants involved in the process,51 were female.They provided 48 suggestions.Their suggestions were integrated into six intervention components during dialogue meetings:(1)use CHWs and a health committee for collecting and transmitting community concerns about health services,(2)build the capacity of the community in terms of knowledge and information,(3)involve community leaders through dialogue meetings,(4)improve the attitude of HPs towards voice and the management of voice at health facility level,(5)involve the health service supervisors in community participation and;(6)use other existing interventions.These components were then articulated into three intervention components during programming to:create a formal voice system,introduce dialogue meetings improving enforceability and answerability,and enhance the health providers’responsiveness.Conclusions:The use of the Dialogue Model,a participatory process,allowed beneficiaries to be involved with other community stakeholders having different perspectives and types of knowledge in an advisory process and to articulate their suggestions on a combination of SA intervention components,specific for the two health zones contexts.
基金supported by the National Natural Science Foundation of China(Grant Nos.61233001 and 61322307)the Fundamental Research Funds for Central Universities of China(Grant No.2013JBZ007)
文摘The pedestrians can only avoid collisions passively under the action of forces during simulations using the social force model, which may lead to unnatural behaviors. This paper proposes an optimization-based model for the avoidance of collisions, where the social repulsive force is removed in favor of a search for the quickest path to destination in the pedestrian's vision field. In this way, the behaviors of pedestrians are governed by changing their desired walking direction and desired speed. By combining the critical factors of pedestrian movement, such as positions of the exit and obstacles and velocities of the neighbors, the choice of desired velocity has been rendered to a discrete optimization problem. Therefore,it is the self-driven force that leads pedestrians to a free path rather than the repulsive force, which means the pedestrians can actively avoid collisions. The new model is verified by comparing with the fundamental diagram and actual data. The simulation results of individual avoidance trajectories and crowd avoidance behaviors demonstrate the reasonability of the proposed model.
基金supported by the National Natural Science Foundation of China(Grant Nos.61322307 and 61233001)
文摘With the development of urban rail transit, ensuring the safe evacuation of pedestrians at subway stations has become an important issue in the case of an emergency such as a fire. This paper chooses the platform of line 4 at the Beijing Xu- anwumen subway station to study the emergency evacuation process under fire. Based on the established platform, effects of the fire dynamics, different initial pedestrian densities, and positions of fire on evacuation are investigated. According to simulation results, it is found that the fire increases the air temperature and the smoke density, and decreases pedestrians'- visibility and walking velocity. Also, there is a critical initial density at the platform if achieving a safe evacuation within the required 6 minutes. Furthermore, different positions of fire set in this paper have little difference on crowd evacuation if the fire is not large enough. The suggestions provided in this paper are helpful for the subway operators to prevent major casualties.
基金supported by Shanghai Science and Technology Committee (No. 08515810200)Jiangsu Province Development Foundation (No. BS2007048)
文摘This paper presents a model for simulating crowd evacuation and investigates three widely recognized problems. For the space continuity problem, this paper presents two computation algorithms: one uses grid space to evaluate the coordinates of the obstacle's bounding box and the other employs the geometry rule to establish individual evacuation routes. For the problem of collision, avoidance, and excess among the individuals, this paper computes the generalized force and friction force and then modifies the direction of march to obtain a speed model based on the crowd density and real time speed. For the exit selection problem, this paper establishes a method of selecting the exits by combining the exit's crowd state with the individuals. Finally, a particle system is used to simulate the behavior of crowd evacuation and produces useful test results.
基金Project(70972041)supported by the National Natural Science Foundation of ChinaProject(20100009110010)supported by the PhD Programs Foundation of Ministry of Education of ChinaProject(2011YJS246)supported by Fundamental Research Funds for the Central Universities of China
文摘Pedestrian's road-crossing model is the key part of micro-simulation for mixed traffic at signalized intersection.To reproduce the crossing behavior of pedestrians,the microscopic behaviors of the pedestrians passing through the crosswalk at signalized intersection were analyzed.A pedestrian's decision making model based on gap acceptance theory was proposed.Based on the field data at three typical intersections in Beijing,China,the critical gaps and lags of pedestrians were calibrated.In addition,considering pedestrian's required space,a modification of the social force model that consists of a self-deceleration mechanism prevents a simulated pedestrian from continuously pushing over other pedestrians,making the simulation more realistic.After the simple change,the modified social force model is able to reproduce the fundamental diagram of pedestrian flows for densities less than 3.5 m-2 as reported in the literature.
基金Project supported jointly by the National Natural Science Foundation of China(Grant Nos.61322307 and 2016YJS023)
文摘The bottleneck effect on bidirectional crowd dynamics is of great theoretical and practical significance, especially for the designing of corridors in public places, such as subway stations or airports. Based on the famous social force model, this paper investigates the bottleneck effects on the free flow dynamics and breakdown phenomenon under different scenarios, in which different corridor shapes and inflow ratios are considered simultaneously. Numerical simulation finds an interesting self-organization phenomenon in the bidirectional flow, a typical characteristic of such a phenomenon is called lane formation, and the existence of which is independent of the corridor's shape and inflow rate. However, the pattern of the lane formed by pedestrian flow is related to the corridor's shape, and the free flow efficiency has close relationship with the inflow rate. Specifically, breakdown phenomenon occurs when inflows from both sides of the corridor are large enough, which mostly originates from the bottleneck and then gradually spreads to the other regions. Simulation results further indicate that the leaving efficiency becomes low as breakdown occurs, and the degree of congestion is proportional to the magnitude of inflow. The findings presented in this paper match well with some of our daily observations, hence it is possible to use them to provide us with theoretical suggestions in design of infrastructures.
基金the National Natural Science Foundation of China(Grant No.62003182)。
文摘Under the background of Covid-19 sweeping the world,safe and reasonable passenger flow management strategy in subway stations is an effective means to prevent the spread of virus.Based on the social force model and the minimum cost model,the movement and path selection behavior of passengers in the subway station are modeled,and a strategy for passenger flow management to maintain a safe social distance is put forward.Take Qingdao Jinggangshan Road subway station of China as the simulation scene,the validity of the simulation model is verified by comparing the measured value and simulation value of the time required for passengers from getting off the train to the ticket gate.Simulation results indicate that controlling the time interval between incoming passengers at the entrance can effectively control the social distance between passengers and reduce the risk of epidemic infection.By comparing the evacuation process of passengers under different initial densities,it is found that the greater the initial density of passengers is,the longer the passengers are at risk social distance.In the process of passenger emergency evacuation,the stairs/escalators and ticket gates are bottleneck areas with high concentration of passenger density,which should be strictly disinfected many times on the basis of strictly checking the health code of incoming passengers and controlling the arrival time interval.The simulation results of this paper verify the harmfulness of passenger emergency evacuation without protective measures,and provide theoretical support for the operation and management of subway station under the epidemic situation.
基金Project supported by the National Natural Science Foundation of China(Grant No.61233001)the Fundamental Research Funds for the Central Universities,China(Grant No.2017JBM014)
文摘This paper focuses on the simulation analysis of stripe formation and dynamic features of intersecting pedestrian flows.The intersecting flows consist of two streams of pedestrians and each pedestrian stream has a desired walking direction.The model adopted in the simulations is the social force model, which can reproduce the self-organization phenomena successfully. Three scenarios of different cross angles are established. The simulations confirm the empirical observations that there is a stripe formation when two streams of pedestrians intersect and the direction of the stripes is perpendicular to the sum of the directional vectors of the two streams. It can be concluded from the numerical simulation results that smaller cross angle results in higher mean speed and lower level of speed fluctuation. Moreover, the detailed pictures of pedestrians' moving behavior at intersections are given as well.
基金This paper is supported by National Nature Science Foundation of China (No.70472034).
文摘The paper builds up a cost-benefit measuring model of green products in manufacturing industry throughout its full life cycle, which can quantify green products' cost and benefit completely and correctly under the circumstance of satisfying enterprise, customer, environment and society. It also puts forth an operable method to estimate social benefit by opportunity cost and establishes a profit maximization-programming model. The model can be applied to justify whether some kinds of green products should be developed and produced.
基金Project supported jointly by the National Natural Science Foundation of China(Grant No.61233001)the Fundamental Research Funds for Central Universities of China(Grant No.2013JBZ007)
文摘Analysis of dynamic features of pedestrian flows is one of the most exciting topics in pedestrian dynamics. This paper focuses on the effect of homogeneity and heterogeneity in three parameters of the social force model, namely desired velocity, reaction time, and body size, on the moving dynamics of bidirectional pedestrian flows in the corridors. The speed and its deviation in free flows are investigated. Simulation results show that the homogeneous higher desired speed which is less than a critical threshold, shorter reaction time or smaller body size results in higher speed of flows. The free dynamics is more sensitive to the heterogeneity in desired speed than that in reaction time or in body size. In particular, an inner lane formation is observed in normal lanes. Furthermore, the breakdown probability and the start time of breakdown are focused on. This study reveals that the sizes of homogeneous desired speed, reaction time or body size play more important roles in affecting the breakdown than the heterogeneities in these three parameters do.