Text this: (s, S) policy model for liner shipping refueling and sailing speed optimization problem

  ____       ___       _____     ___    __    __  
 |  _ \\    / _ \\    / ___//   / _ \\  \ \\ / // 
 | |_| ||  / //\ \\   \___ \\  / //\ \\  \ \/ //  
 | .  //  |  ___  ||  /    // |  ___  ||  \  //   
 |_|\_\\  |_||  |_|| /____//  |_||  |_||   \//    
 `-` --`  `-`   `-` `-----`   `-`   `-`     `