Research Experiences

  • Postdoctoral Research Fellow (02/2008 – 02/2009)

Center for Intelligent Material Systems and Structures (CIMSS)

Dept. of Mechanical Engineering, Virginia Polytechnic Institute and State University

Director: Prof. Daniel J. Inman (dinman@vt.edu)

- Fatigue crack detection using nonlinear impedance features

- Multi-scale structural health monitoring incorporating vibration, impedance, and guided waves

- Structural damage detection using a DSP-based online guided wave generation/reception system

  • Adjunct Researcher (04/2008 – 06/2008)

Intelligent IT System Research Center

Korea Electronics Technology Institute

Director: Dr. Hyung-Su Lee (hslee@keti.re.kr)

- Developing a ubiquitous sensor network(USN)-based structural health diagnosis system

- Developing a USN-GIS (geographic information system)-based intelligent management/ monitoring system

for underground facilities

  • Visiting Scientist (06/2006 – 07/2006)

The Engineering Institute, Los Alamos National Laboratory

Director: Dr. Charles R. Farrar (farrar@lanl.gov)

- Developed an electro-mechanical impedance model for piezoelectric sensor self-diagnosis

  • Visiting Scholar (Supported by KRF-Internship Fellowship) (09/2005 – 08/2006)

Center for Intelligent Material Systems and Structures (CIMSS)

Dept. of Mechanical Engineering, Virginia Polytechnic Institute and State University

Director: Prof. Daniel J. Inman (dinman@vt.edu)

- Embedded an outlier analysis-based damage detection algorithm into a miniaturized impedance measuring chip

device

- Embedded a principal component analysis (PCA)-based data compression algorithm for wireless data transmission

into the active sensor node

- Applied a wireless digital signal processor (DSP) module to impedance measurements

- Incorporated impedance and guided waves-based damage detection techniques for real-time structural health

monitoring of railroads

- Performed numerical simulations for piezoelectric impedance measurements using ANSYS


  • Research Graduate Student (03/2002 – 01/2008)

Smart Infra-Structures Technology Center (SISTeC)

Dept. of Civil and Environmental Engineering, KAIST

Advisor/Director: Prof. Chung-Bang Yun (ycb@kaist.ac.kr)

- Developed piezoelectric active sensor network system to diagnose structural damage on the welded zone of a steel

truss bridge member

- Developed a wireless active sensor node for impedance-based structural health monitoring

- Developed temperature compensation techniques on piezoelectric impedance measurements

- Developed statistical pattern recognition tools including neural networks, support vector machine and outlier

analysis to detect and classify structural damages

- Incorporated PZT-induced Lamb waves and statistical pattern recognition tools (probabilistic neural network and

support vector machine) for on-line health monitoring

- Performed both experimental and analytical studies for impedance-based structural health monitoring of reinforced

concrete structures