Mean-field game analysis of crowd evacuation using the Cristiani-Santo-Menci method.

In this paper, we investigate the crowd evacuation from a room on the basis of the mean field game theory. In particular, effects of the predictability of pedestrians on the evacuation process are considered by applying the Cristiani-Santo-Mensi method as a solver of the Hamilton-Jacobi-Bellman equation coupled with the Fokker-Planck equation. Some numerical tests of the crowd evacuation from a room are implemented in order to investigate effects of the predictability, mass diffusion, interactive force and domain, and form of the running cost function on the evacuation process. Finally, we investigate effects of the predictability on the evacuation process, when two exits are opened and closed, alternatively.

Effect of form of obstacle on speed of crowd evacuation.

This paper investigates the effect of the form of an obstacle on the time that a crowd takes to evacuate a room, using a toy model. Pedestrians are modeled as active soft matter moving toward a point with intended velocities. An obstacle is placed in front of the exit, and it has one of four shapes: a cylindrical column, a triangular prism, a quadratic prism, or a diamond prism. Numerical results indicate that the evacuation-completion time depends on the shape of the obstacle. Obstacles with a circular cylinder (C.C.) shape yield the shortest evacuation-completion time in the proposed model.

[The current situation and agendas in the prevention and control of non-communicable diseases in Vietnam].

Objectives　In Vietnam, the number of patients with non-communicable diseases (NCDs) has been increasing in recent years in association with the country's remarkable economic growth and corresponding changes in its population's lifestyle. The purposes of this research were to identify the challenges in the prevention and control of NCDs in Vietnam and to discuss countermeasures for NCDs in Vietnam and Japan.Methods　As a 2015 Regional Public Health Overall Promotion Project, an investigation team consisting of 11 public health physicians visited Hanoi, the capital of Vietnam, and its vicinities from January 11, 2016 to January 15, 2016. In Hanoi and its vicinities, we visited local healthcare institutions, such as the World Health Organization(WHO) Representative Office in Vietnam and Ministry of Health of Vietnam, and discussed the prevention and control of NCDs in Vietnam and Japan.Results　According to a survey in 2014, 73% of people of all age groups in Vietnam died from NCDs and the number of people suffering from NCDs has been sharply increasing in recent years. Major behavioral risk factors are dietary risks, tobacco smoke, alcohol use, and physical inactivity. There are four main problems with prevention and control of NCDs: 1) low awareness among the people of NCDs, 2) regional disparity of medical services, 3) shortage of healthcare staff members with professional knowledge, and 4) poor NCD surveillance.　In Vietnam, an NCD program with screening methods and medical guidelines for respective diseases was developed in 2002. However, it only covered tertiary prevention and did not fully describe the primary and secondary prevention measures. Currently, with the technical assistance of the WHO, the implementation of countermeasures emphasizing prevention and control to reduce NCD risk factors has only just begun.Conclusion　It was considered that educating each person in Vietnam on NCD prevention measures would be necessary and that a national policy, like Healthy Japan 21 of Japan, and a nationwide screening project, such as specific medical checkups, could serve as a useful reference. We found that public health activities in Japan to penetrate a region mainly involving public health nurses had played important roles for Japanese people's health. Furthermore, Japan shares with Vietnam the challenges including the shortage of human resources, and therefore, the securement of healthcare staff members who confront health challenges and the enhancement of their abilities is required.

Kinetic Modeling of Local Epidemic Spread and Its Simulation.

The local epidemic spread in physical space is modeled using the kinetic equation. In particular, the infection occurs via the binary interaction between the uninfected and infected individuals. Then, the local epidemic spread can be modeled on the basis of the stochastic Boltzmann type equation. In this paper, the normalized virus titer inside the infected human body is defined as the function of the elapsed time, which is measured from the infection time. Consequently, the probability of the infection at the binary human interaction increases, as the normalized virus titer inside the human body increases, whereas the normalized virus titer inside the infected human body decreases, after the normalized virus titer reaches to its maximum value, namely, unity, in the characteristic time. Numerical results indicate that the propagation speed of the boundary between the infected and uninfected domains depends on such a characteristic time, strongly, when the Knudsen number and temperature are fixed. Such a dependency of the propagation speed of the boundary between the infected and uninfected domains on the characteristic time can be described by the Fisher-Kolmogorov-Petrovsky-Piscounov equation which is introduced from the stochastic Boltzmann type equation. Finally, we consider three types of the human behavior as plausible actions to the local epidemic spread.