A volunteer node can join and leave a volunteer computing system freely. However, existing volunteer computing systems suffer from interruptions of job execution, delays of execution time, and increases of total execution time, since they do not consider dynamic scheduling properties (i.e. volatilities), such as leave, join, and suspension. Therefore, dynamic execution properties of volunteer node should be considered in scheduling schemes, in order to design a stable and reliable volunteer computing system. This paper proposes a new scheduling scheme based on the Dedication Rate (DR), which reflects the dynamic properties of a volunteer. The scheduling scheme improves the completeness and reliability of execution, while also decreasing delay and total execution time. In addition, an implementation of the proposed scheduling scheme on top of Korea@Home is described, as well as performance evaluation.