An Evacuation Model for Passenger Ships That Includes the Influence of Obstacles in Cabins

Passenger behavior and ship environment are the key factors affecting evacuation efficiency. However, current studies ignore the interior layout of passenger ship cabins and treat the cabins as empty rooms. To investigate the influence of obstacles (e.g., tables and stools) on cabin evacuation, we propose an agent-based social force model for advanced evacuation analysis of passenger ships; this model uses a goal-driven submodel to determine a plan and an extended social force submodel to govern the movement of passengers. The extended social force submodel considers the interaction forces between the passengers, crew, and obstacles and minimises the range of these forces to improve computational efficiency. We drew the following conclusions based on a series of evacuation simulations conducted in this study: (1) the proposed model endows the passenger with the behaviors of bypassing and crossing obstacles, (2) funnel-shaped exits from cabins can improve evacuation efficiency, and (3) as the exit angle increases, the evacuation time also increases. These findings offer ship designers some insight towards increasing the safety of large passenger ships

Agent-Based Evacuation in Passenger Ships Using a Goal-Driven Decision-Making Model

A new agent-based model is proposed to support designers in assessing the evacuation capabilities of passenger ships and in improving ship safety. It comprises models for goal-driven decision-making, path planning, and movement. The goal-driven decision-making model determines an agent’s target by decomposing abstract goals into subgoals. The path-planning model plans the shortest path from the agent’s current position to its target. The movement model is a combination of social-force and steering models to control the agent in moving along its path. The utility of the proposed model is verified using 11 tests for passenger ships proposed by the Maritime Safety Committee of the International Maritime Organization

An Evacuation Model for Passenger Ships That Includes the Influence of Obstacles in Cabins

Passenger behavior and ship environment are the key factors affecting evacuation efficiency. However, current studies ignore the interior layout of passenger ship cabins and treat the cabins as empty rooms. To investigate the influence of obstacles (e.g., tables and stools) on cabin evacuation, we propose an agent-based social force model for advanced evacuation analysis of passenger ships; this model uses a goal-driven submodel to determine a plan and an extended social force submodel to govern the movement of passengers. The extended social force submodel considers the interaction forces between the passengers, crew, and obstacles and minimises the range of these forces to improve computational efficiency. We drew the following conclusions based on a series of evacuation simulations conducted in this study: (1) the proposed model endows the passenger with the behaviors of bypassing and crossing obstacles, (2) funnel-shaped exits from cabins can improve evacuation efficiency, and (3) as the exit angle increases, the evacuation time also increases. These findings offer ship designers some insight towards increasing the safety of large passenger ships

Arginine vasopressin in hypothalamic paraventricular nucleus is transferred to the nucleus raphe magnus to participate in pain modulation

abstract: Hypothalamic paraventricular nucleus (PVN) is one of the main sources of arginine vasopressin (AVP) synthesis and secretion. AVP is the most important bioactive substance in PVN regulating pain process. Our pervious study has pointed that pain stimulation induced AVP increase in the nucleus raphe magnus (NRM), which plays a role in pain modulation. The present study was designed to investigate the source of AVP in the rat NRM during pain process using the methods of nucleus push–pull perfusion and radioimmunoassay. The results showed that pain stimulation increased the AVP concentration in the NRM perfusion liquid, PVN cauterization inhibited the role that pain stimulation induced the increase of AVP concentration in the NRM perfusion liquid, and PVN microinjection of l-glutamate sodium, which excited the PVN neurons, could increase the AVP concentration in the NRM perfusion liquid. The data suggested that AVP in the PVN might be transferred to the NRM to participate in pain modulation