Address. Yoshiyuki Watanabe, Department of Mathematics, Faculty of Science, Toyama University, Toyama 930, JAPAN
Hiroshi Mori, Department of Mathematics, Joeteu University of Education, Joetsu, Niigata Pref. 943, JAPAN
Abstract. We construct a family of almost quaternionic Hermitian structures from an almost contact metric 3-structure and also do three kinds of quaternionic Kahler structures from a Sasakian 3-structure. In particular we have a generalization of the second main result of Boyer-Galicki-Mann .
AMSclassification. 53C25, 53C15
Keywords. almost contact metric 3-structure, Sasakian 3-structure, almost quaternionic Hermitian manifold, quaternionic Kahler manifold, hyperkahler manifold