Brilliant rows of tulips in red, yellow, and white surround a glass pavilion at Keukenhof in the Netherlands. The carefully ...

This video shows a metro station entrance in Guangzhou, China, surrounded by high rise buildings, shops, and busy streets. A clearly marked subway access point connects pedestrians to the underground ...

† School of Mechanical Engineering, Kyungpook National University, 80 Daehak-ro, Buk-gu, Daegu 41566, Repulic of Korea ‡ Department of Mechanical Engineering, Gumi University, 37 Yaeun-ro, Gumi, ...