- In 1988: Ph. D in the
**University of California at Berkeley**under the supervision of Alan Weinstein with my thesis entitled

**``Semi-classical bound states of nonlinear Schroedinger equations under potentials ; existence, evolution and stability''**.

With this thesis, I received the Bernard Friedman Memorial Prize in Applied Math. at the Commencement of UC-Berkeley in May 1988. - For the year 1988-1989 : post-doc member of
**MSRI**where I started to work on various aspects of

**Lagrangian submanifolds**in symplectic geometry and Riemannian geometry. During this time, I wrote one more paper on nonlinear Schroedinger equation

and started my research on the geometry and topology of Lagrangian submanifolds.

I wrote the paper on minimal Lagrangian submanifolds and did some preliminary work on my attempt to generalize the definition of the

**Lagrangian intersection Floer cohomology**beyond Floer's original construction. - For the years 1989 - 1991 : Courant Instructor in
**Courant Institute**of New York University.

The first work on Lagrangian intersection Floer cohomology is completed. Two papers on the subject were published in Comm. Pure Applied Math. a year later.

**Andreas Floer**died in Spring 1991. - In 1991-1992 : a member of
**Institute for Advanced Study**in Princeton where research on the Floer theory is continued. - Since 1992, I have been
in the
**University of Wisconsin**at Madison starting as a tenure-track Assistant Professor.

I was promoted to Associate Professor in 1997 and to Professor in 2001. - In the fall of 1994 :
I took one semester un-paid leave for the
program ``Symplectic Geometry'' in the
**Newton Institute**in Cambridge, England with the EPSRC visiting fellowship.

Here I completed my paper on application of the Floer homology to the study of topology of Lagrangian embeddings

and initiated the study of adiabatic degeneration of the Floer moduli spaces with Kenji Fukaya . - For the years 1998-2000 : A leave for the professorship in
the
**Korea Insitute for Advanced Study ( KIAS)**in Seoul, Korea,

where the study of**spectral invariants**of Hamiltonian flow is started. - In the year 2001-2002 : A leave
for the participation in the program
``Holomorphic curves and Symplectic geometry'' in IAS,

I continued the research on the spectral invariants and completed a series of papers on the subject of spectral invariants

and their applications which led me to the new research topic of**topological Hamiltonian dynamical systems**. - In 2004-2005 : A sabbatical leave in
**Stanford University**, where I started my project of writing a graduate level textbook

on Floer homology theory and its applications. - I also spent some summers in
**IHES**, France in 1992 and 1997. Around this time, the project of writing the research monograph [FOOO]

**Lagrangian Intersection Floer theory : anomaly and obstruction**in collaboration with**K. Fukaya, H. Ohta and K. Ono**is started.

The first preprint version is finished in the year 2000. - The years 1998 - 2008 : I have been spending most of my summer time in KIAS, Seoul, Korea.
- In August 2006 : An invited lecture with a title
``Floer homology in symplectic geometry and mirror symmetry''

in the session (Geometry) of the International Congress of Mathematicians (ICM-2006) held in Madrid, Spain for August 22 - 30, 2006. - In 2008 : A new collaboration with Fukaya, Ohta and Ono is started on the project of applying the Floer theory from [FOOO] to the toric manifolds.
- In August 2008, the final version of the book ``Lagrangian intersection Floer theory : anomaly and obstruction'' [FOOO] is completed.
- In Fall 2009, I took an unpaid leave in National Institute
for Mathematical Sciences
(
**NIMS**) in Korea to serve as a visiting chair professor

and ran a thematic program of ``Symplecic Topology and Mirror Symmetry''. - Starting from Summer 2010, I am affiliated to
**POSTECH**as a (part-time) University Distinguished Professor.