TINAves, likely no way to know for sure, however if we read through the postings, there are clues to the likelihood of whether new positions or not.

The three higher level postings contain key terms such as:

To develop and integrate design process flows; To develop test setup and capabilities; Design and develop a product or product family; Execute product design activities; Participates in new product development; Support the test requirement of new product innovation; Contribute to the build-up of the Advanced Photonics Engineering Lab, etc.etc.

The implication is that these are for work not previously performed, and current personnel are either unqualified or unavailable to perform the duties.  ie new positions.   Vacancies seem less likely, after all, why would you have vacant positions (fired or quit?) for work you have not performed before.  I suppose some these could have been for very recent hires that just didn't work out, but this also seems less likely than the new position scenario.  IMO of course.