Purpose: To investigate the pre-operative and post-operative objective optical quality after overnight orthokeratology (ortho-k). Methods: Twenty two patients (43 eyes) satisfying the inclusion criteria (myopia < -4.50 D, astigmatism < -1.50 D, K-reading: 40.00 ~ 46.75 D) for overnight ortho-k. Visual acuity (VA) was measured by using System Chart (SC-2000, Nidek). Objective optical quality measurements were performed using the Optical Quality Analysis System (OQAS Visionmetrics SL, Spain) for modulation transfer function (MTF), strehl ratio, and objective scattering index (OSI). Statistical analyses were performed with SPSS 18.0 (SPSS Inc, Chicago, Illinois) and p value less than 0.05 was considered statistically significant. Results: The MTF values were 42.61 ± 8.39 pre-operatively, and 37.88 ± 11.77 post-operatively that there was no significant difference (p = 0.075). The strehl ratios were 0.24 ± 0.08, and 0.20 ± 0.05, respectively that there was significant difference between pre- and post-ortho-K (p = 0.001). OSI value were 0.37±0.17 and 0.71 ± 0.37, respectively, which were statistically significant (p < 0.000). According to OSI values, the mean value of VA was 0.05 ± 0.06 logMAR in the over 0.40 OSI group and 0.01 ± 0.05 logMAR in the less 0.40 OSI group that there was no significant difference (p = 0.085). Conclusions: There were no significant difference in the objective visual quality such as MTF between pre- and post-ortho-K. The postoperative Strehl ratio was decreased and OSI value was increased significantly compared with pre-operation, however, increase in the OSI would not influence on the UCVA.

Modification of C/C composite bipolar plate for improving electrical conductivity was carried out by addition of electroconductive carbon black (EC-CB). Carbon black was carefully mixed to methanol-containing phenolic resin, impregnated into 2D-carbon fabrics, hot pressed and then carbonized to obtain composite plate. Inclusion of electro-conductive carbon black enhanced the electrical conductivity of the C/C composites by increasing the conduction path. Addition of 10 vol% carbon black increased the electrical conductivity from 5.5/Ωcm to 32/Ωcm and reduced the crack formation by filling effect, resulting in the increase of flexural properties of composite plate. However, at carbon black content over 10 vol%, flexural properties decreased by delaminating role of excess carbon black at the interface in C/C composites.

PangYak-Happyon(方藥合編) is probably the most widely circulated and highly valued as an indispensable manual of medical prescriptions among the practising Korean herb-doctors since its first publication in 1884. The book was compiled by a man named Hwang Toyon(黃度淵, 1807～1884), who established himself in the nations capital, Seoul, as a practioner in Oriental Medicine for many years and later became very famous for his competence as a doctor. He is known to have served even as the chief attending physician on the reigning monarch, King Kojong. The main purpose of this paper is to analyze the structure or composition of the book and evaluate the reliability and effective value as a manual in the medical field. The paper also dealt with the significant role the book has been playing in Korean medical field, even into present day. One of the conclusions the author reached through this study is that the book is so well organized in many ways to serve as the most useful guidance for the doctors, and some of the concrete aspects of the organization is examined in detail in this paper.