PPCSOn Behalf of the PPCS Organizing Committee, I welcome all of you to this signature event of the 17th PPCS in Kaohsiung, Taiwan, on Oct 14-15, 2023. It has been 15 years since we got together in Kaohsiung at the 3rd PPCS in 2008 and celebrated the 7oth birthday of Professor William Chet de Groat.