@article{oai:muroran-it.repo.nii.ac.jp:00009971, author = {TAKAHASHI, Masatomo and 高橋, 雅朋}, issue = {1}, journal = {Journal of Mathematical Analysis and Applications}, month = {May}, note = {application/pdf, For families of hypersurfaces with singular points, a classical definition of an envelope is vague. In order to define an envelope for a family of hypersurfaces with singular points, we consider r-parameter families of frontals and of Legendre mappings in the unit tangent bundle over the Euclidean space. We define an envelope for the r-parameter family of Legendre mappings. Then the envelope is also a frontal. We investigate properties of the envelopes. As an application, we give a condition that the projection of a singular solution of a first order partial differential equation is an envelope.}, pages = {408--420}, title = {Envelopes of families of Legendre mappings in the unit tangent bundle over the Euclidean space}, volume = {473}, year = {2019}, yomi = {タカハシ, マサトモ} }