The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
We investigate the problem of minimizing the makespan (resp. the sum of completion time) for the multiprocessor scheduling problem. We show that there is no hope of finding a ρ-approximation with ρ<1+1/(c+4) for minimization of the makespan (resp. 1+1/(2c+5) for total job completion time minimization) (unless P=NP) for the case where all the tasks of the precedence graph have unit execution times,...