A system management apparatus for managing a computer system receives plug-in distribution data from a plug-in distribution apparatus. Contextual information associated with the data objects and the activity is collected to establish the relationship. Optical filtering is used to limit the infrared radiation to relevant wavelengths. An output shaft to be driven by a power of the counter shaft penetrates through the front and rear walls of one of the upper and lower crankcases by which the main shaft is not rotatably supported, and projects to the front and rear. Also, the invention relates to a main electric circuit for performing testing and measurements on a plurality of cells in parallel.