Two methods used in this study. (IMAGE) Beijing Zhongke Journal Publising Co. Ltd. Caption This picture shows the following two methods with different inputs and outputs. Credit Beijing Zhongke Journal Publising Co. Ltd. Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.