She has been involved in precision calculations of Quantum Electrodynamic(QED), such as energy spectra of simple hydrogen-like atoms and the anomalous magnetic moments of the electron and the muon. The results of the calculations are used to determine the value of the fine-structure constant that governs any electro-magnetic phenomena. The QED results are also essential to test the Standard Model(SM) of elementary particles and to find something new beyond the SM by comparing theoretical predictions to measurements.