When an employee is absent from work, it is necessary to request the substitute attendance of another employee. A problem in this case is which employee to request. An existing algorithm solves the problem by requesting only on the absence day. This paper proposes a new algorithm for requesting on and before the absence day to reduce the excess and deficiency in the number of employees accepting requests. The proposed algorithm determines employees to be requested based on the number of days until the absence day. The performance of the proposed algorithm is empirically evaluated by comparing it with the existing algorithm.

The modeling of gait generation in quadruped animals has been studied in various areas of science and engineering. Especially, it is important for the development of quadruped robots. In this paper, we adopt a model with coupled oscillators, in which, each oscillator is described by a nonlinear differential equation which is refered to as the Stuart-Landau equation. We consider a problem that is related to convergece of the phase differences of the oscillators to the suitable values for walking. Applying phase contraction, the equilibrium points of the phase difference system are analyzed. In order to coordinate the stable equilibrium point to be the suitable values, we clarified the condition and role of the parameters of the coupled oscillators, which are related to the stability of each equilibrium point of the system.