Dear scheduling researcher, We are delighted to announce the talk given by Jinjiang Yuan (Zhengzhou Uni). The title is "Updated complexity results in single-machine primary-secondary scheduling for minimizing two regular criteria". The seminar will take place on Zoom on Wednesday, June 9 at 13:00 UTC. Join Zoom Meeting https://cesnet.zoom.us/j/96998490212?pwd=Zm5QTXdTcnYyeVh5NytCb3NvNUpmUT09 <https://cesnet.zoom.us/j/96998490212?pwd=Zm5QTXdTcnYyeVh5NytCb3NvNUpmUT09> Meeting ID: 969 9849 0212 Passcode: 556764 You can follow the seminar online or offline on our Youtube channel as well: https://www.youtube.com/channel/UCUoCNnaAfw5NAntItILFn4A The abstract follows. In the primary-secondary scheduling problem, we have a primary scheduling criterion and a secondary scheduling criterion. The goal of the problem is to find a schedule which minimizes the second criterion, subject to the restriction that the primary criterion is minimized. Lee and Vairaktarakis [LV1993] presented a comprehensive review for the computational complexity of the single-machine primary-secondary scheduling problems, where all the jobs are released at time zero. When both of the two criteria are regular, more than twenty problems were posed as open in [LV1993]. This talk will report the research progress of these open problems. The next seminar in our series will be given by Mike Carter <https://che.utoronto.ca/professor-michael-w-carter/> (Uni of Toronto) "Challenges in Healthcare Scheduling Applications" and it will be held on June 23 at 13:00 UTC. For more details, please visit https://schedulingseminar.com/ With kind regards Zdenek, Mike and Guohua -- Zdenek Hanzalek Industrial Informatics Department, Czech Institute of Informatics, Robotics and Cybernetics, Czech Technical University in Prague, Jugoslavskych partyzanu 1580/3, 160 00 Prague 6, Czech Republic https://rtime.ciirc.cvut.cz/~hanzalek/