The influence of weather and temperature on pedestrian walking characteristics on the zigzag bridge.

With the increasing number of tourists in recent years, ensuring the safety of visitors in tourist attractions has become an enormous challenge for safety management. At present, many experiments have been conducted to study pedestrian dynamics, but empirical data on tourists' movement state under different weather conditions are still few. Therefore, a series of field experiments were conducted to analyze the effect of external weather and temperature on pedestrians' movement characteristics. The results show that pedestrians are more concentrated in the middle and inner tracks during the turning process to seek the shortest path on rainy days. Moreover, it is found that pedestrians speed up under the conditions with low (below 10 °C) and high (over 30 °C) temperatures. The average speed of pedestrians is 0.677 m/s as the temperature is below 0 °C, which is much higher than the average speed of pedestrians in other temperature ranges. In addition, the speed of pedestrians changed more dramatically under the low-temperature conditions. It is hoped that this research can provide a reference for crowd control and rational design of pedestrian facilities.

Monotonicity of the number of positive entries in nonnegative matrix powers.

Let A be a nonnegative matrix of order n and f ( A ) denote the number of positive entries in A. We prove that if f ( A ) ≤ 3 or f ( A ) ≥ n 2 - 2 n + 2 , then the sequence { f ( A k ) } k = 1 ∞ is monotonic for positive integers k.