Proceedings of the International Joint Conference on Silicon Epitaxy and Heterostructures (IJC-Si) - 8th International Symposium on Silicon Molecular Beam Epitaxy (Si-MBE8) and 3rd International Symposium on Silicon Heterostructures: From physics to devices (Si-HS3) - 12-17 September, 1999 Miyagi-Zao Royal Hotel, Miyagi, Japan - Preface