This study investigates important parameters used to determine an effective peak ground acceleration (EPGA) based on the characteristics of response spectra of historical earthquakes occurred at Korean peninsula. EPGAs are very important since they are implemented in the Korean Building Code for the seismic design of new structures. Recently, the Gyeongju earthquakes with the largest magnitude in earthquakes measured at Korea took place and resulted in non-structural and structural damage, which their EPGAs should need to be evaluated. This paper first describes the basic concepts on EPGAs and the EPGAs of the Gyeongju earthquakes are then evaluated and compared according to epicentral distances, site classes and directions of seismic waves. The EPGAs are dependant on normalizing factors and ranges of period on response spectrum constructed with the Gyeongju earthquake records. Using the normalizing factors and the ranges of period determined based on the characteristics of domestic response spectra, this paper draw a conclusion that the EPGAs are estimated to be about 30 % of the measured peak ground accelerations (PGA).

In the present study, embryoid bodies (EBs) obtained from induced pluripotent stem cells (iPSCs) were induced to differentiate into germ lineage cells by treatment with bone morphogenetic protein 4 (BMP4) and retinoic acid (RA). The results were compared to the results for embryonic stem cells (ESCs) and multipotent spermatogonial stem cells (mSSCs) and quantified using immunocytochemical analysis of germ cell-specific markers (integrin-, GFR-, CD90/Thy1), fluorescence activating cell sorting (FACS), and real time-RT-PCR. We show that the highest levels of germ cell marker-expressing cells were obtained from groups treated with 10 ng/ BMP4 or 0.01 RA. In the BMP4-treated group, GFR- and CD90/Thy-1 were highly expressed in the EBs of iPSCs and ESCs compared to EBs of mSSCs. The expression of Nanog was much lower in iPSCs compared to ESCs and mSSCs. In the RA treated group, the level of GFR- and CD90/Thy-1 expression in the EBs of mSSCs Induced pluripotent stem cells, Mouse embryonic stem cells, Multipotent spermatogonial stem cells, Germ cell lineage, Differentiation potential. was much higher than the levels found in the EBs of iPSCs and similar to the levels found in the EBs of ESCs. FACS analysis using integrin-, GFR-, CD90/Thy1 and immunocytochemistry using GFR- antibody showed similar gene expression results. Therefore our results show that iPSC has the potential to differentiate into germ cells and suggest that a protocol optimizing germ cell induction from iPSC should be developed because of their potential usefulness in clinical applications requiring patient-specific cells.

파랑의 문제에서 진행파 성분 이외에 Laplace 방정식의 또 다른 해인 소멸파 성분은 주로 수심이 급하게 변화할 때 파랑의 변형에 영향을 미친다. 본 연구에서는 고유함수전개법을 사용하여 3차원 함몰 지형에서 파랑의 변형에 대한 소멸파 성분의 영향을 검토하였다. 먼저, 구간의 수와 소멸파 성분의 수에 변화를 주면서 수렴성 검사를 하였으며 다음으로 소멸파 성분을 고려하면서 3차원 함몰지형에서의 파랑변형을 연구하였다.