Determinants of Effecting Customer Loyalty : Comparison among Korean, Japanese and Chinese Online Game Market

이상철,상균영,구자철,서영호,Lee, Sang-Chul,Xiang, Jun-Yong,Gu, Ja-Chul,Suh, Yung-Ho The Korean Operations Research and Management Scie 2006 經營 科學 Vol.23 No.2

The purposes of this research are to identify causalities among flow and customer loyalty In Chinese online games, and to identify the factors by which flow are influenced. This research tests the model with Chinese on-line game users and compare this result with Korea and Japanese results which were conducted by Lee's research. These implications are thought to be helpful for Korean online game companies to understand the Chinese online game user and to develop the penetration strategies. The results indicated that significant Path coefficients to flow were the convenience of operator, the provision of information, the reality of design. The results indicated that significant path coefficients to customer loyalty were the involvement of virtual community and flow. The involvement of virtual community to flow was not significant but to customer loyalty was significant. The provision of information was negatively influenced on flow. The result of comparison indicated that the path coefficients were different among nations. Korea online game companies need to develop the indigenized online game and to Provide the information to their Chinese partner correctly and quickly.

광대싸리잎의 페놀성 화합물에 대한 화학적 연구

이상철,안병태,박웅양,이승호,노재섭,이경순,Lee, Sang-Chul,Ahn, Byung-Tae,Park, Woong-Yang,Lee, Seung-Ho,Ro, Jai-Seup,Lee, Kyong-Soon 한국생약학회 1994 생약학회지 Vol.25 No.2

A chemical examination of the aqueous acetone extract of the leaves of Securinega suffruticosa has led to the isolation of nine phenolic compounds. On the basis of chemical and spectroscopic evidences, the structures of these compounds were established to be gallic acid(1), corilagin(2), helioscopinin B(3), geraniin(4), bergenin (5), norbergenin(6), 11-O-galloyl norbergenin(7), gallocatechin(8) and rutin(9).

전산화단층사진을 이용한 타액선의 정량분석에 관한 연구

이상철,이삼선,허민석,최순철,박태원,유동수,Lee Sang-Chul,Lee Sam-Sun,Heo Min-Suk,Choi Soon-Chul,Park Tae-Won,You Dong-Soo 대한영상치의학회 1999 Imaging Science in Dentistry Vol.29 No.1

Purpose: The purpose of this study was to calculate the size and CT number of both normal parotid and submandibular gland. and evaluate their relation to sex, age and obesity using computed tomography. Materials and Methods: The computed tomography was performed parallel to the Frankfurt plane in 46 subjects with healthy salivary gland. The subjects were divided into the three groups (young, middle. old) according to their ages. The size of salivary gland was determined as maximum cross-sectional area and the CT number of salivary gland was determined as the mean CT number of three ROI's. The body mass index was calculated from weight and height. Results: The mean maximum cross-sectional area was 7.79(±1.25)cm² on parotid gland and 4.12(±0.83) cm² on submandibular gland. The mean CT number was -4.43(±23.87) HU on parotid gland and 50.01(±15.63) HU on submandibular gland. There was decreasing pattern of the maximum cross-sectional area of submandibular gland and the CT number of both parotid and submandibular gland according to age(p<0.05). As the body mass index increased. the maximum cross-sectional area of parotid gland increased and CT number of both parotid and submandibular gland decreased(p<0.05). The maximum cross-sectional area of submandibular gland in male was larger than that in female(p<0.05). As the maximum cross-sectional area and CT number of left salivary gland increased. those of right gland increased(p<0.05). Conclusion : Intra-individual differences in salivary gland size and CT number is considered in the age and individual obesity.

Rhizobium trifolii Malonyl-CoA Synthetase의 촉매반응에 관여하는 아미노산 Residue의 화학변형

이상철,김유삼,Lee, Sang-Chul,Kim, Yu-Sam 생화학분자생물학회 1993 한국생화학회지 Vol.26 No.3

Rhizobium tnifolii에서 정제한 malonyl-CoA synthetase가 2,3-butanedione과 diethylpyro-carbonate(DEP)에 의해 불활성화 되었다. 각 불활성화 반응은 pseudo first-order kinetics으로 나타났다. 2,3-Butanedion에 의한 효소의 불활성화 반응의 2차 속도상수는 pH 8.0, $30^{\circ}C$에서 $17.4M^{-1}{\cdot}min^{-1}$이었다. DEP에 의해 효소가 빠르게 불활성화되었으며 반응의 2차속도상수는 pH 7.1, $30^{\circ}C$ 에서 $780M^{-1}{\cdot}min^{-1}$이었다. 각 시약과 반응차수는 1.06과 1.03이였다. ATP가 위의 2가지 시약에 의한 효소의 불활성화를 저해하였다. 이러한 결과들은 malonyl-CoA synthetase의 ATP 결합부위나 그 주위에 효소활성에 필수적인 arginine residue와 histidyl residue가 존재함을 시사한다. Malonyl-CoA synthetase from Rhizobium trifolii was inactivated by 2,3-butanedione and diethylpyrocarbonate (DEP). In each case, inactivation followed pseudo first-order kinetics. The second-order rate constant for the inactivation by 2,3-butanedione was $17.4M^{-1}{\cdot}min^{-1}$ at pH 8.0, $30^{\circ}C$. DEP rapidly inactivated the enzyme with the second-order rate constant, $780M^{-1}{\cdot}min^{-1}$ at pH 7.1, $30^{\circ}C$. The reaction order of inactivation with respect to reagents were 1.06 and 1.03 respectively. The substrate, ATP, afforded the protection against the inactivation of the enzyme caused by the reagent, respectively. These results indicate that arginine and histidyl residues essential for the enzyme activity are located at or near the ATP binding region of the active site.

Identification of Essential Cysteine and Arginine Residues in Glucose-6-phosphate Dehydrogenase from the Uropygial Gland of Duck

이상철,김유삼,Lee, Sang-Chul,Kim, Yu-Sam 생화학분자생물학회 1985 한국생화학회지 Vol.18 No.2

오리의 uropygial gland로 부터 pI 6.6인 glucose-6-phosphate dehydorgenase를 순수하게 정제하여 효소활성과 기질 및 보조효소와의 결합에 관여하는 아미노산에 대해 조사하였다. Cysteine의 -SH기에 특이하게 반응하는 p-chloromercuriphenylsulfonic acid, 5,5'-dithio-bis-(2-nitrobenzoic acid), N-ethylmaleimide와 arginine의 guanidino기에 특이하게 반응하는 phenylglyoxal 등이 효소의 활성을 억제한다는 사실로 보아 효소의 active site나 그 근처에 cysteine과 arginine이 존재하는 것으로 예상된다. 또한 glucose-6-phosphate가 존재할 때 이 reagent들에 의한 효소의 활성억제에 아무런 영향이 없었으나 $NADP^+$존재하에서는 효소의 활성억제 현상이 크게 감소한다는 사실로 미루어 cysteme과 arginine이 $NADP^+$와 효소가 결합하는 위치냐 또는 그 부근에 있는 것으로 판단된다. $Mg^{++}$이 존재할 때 p-chloromercuriphenylsulfonic acid, 5,5'-dithio-bis(2-nitrobenzoic acid)와 phenylglyoxal에 의한 효소의 활성 억제가 더 크게 나타났는데, 이러한 사실은 EDTA와 $Mg^{++}$이 공존할 때 이 reagent에 의한 활성 억제가 EDTA가 존재하지 않을 때 보다 감소하였다는 것으로 보아 $Mg^{++}$이 이 reagent에 의한 효소의 활성 억제를 증가시킨다는 사실을 확인하였다. Glucose-6-phosphate dehydrogenase from the uropygial gland of duck was purified in an electrophoretically homogenous form and its essential amino acid for catalysis was investigated. Three -SH group directed reagents, p-chloromercuriphenylsulfonic acid, 5,5'-dithio-bis-(2-nitrobenzoic acid) and N-ethylmaleimide, inhibited the enzyme activituy, and arginine directed reagent, phenylglyoxal, also inhibited the enzyme activity. The inhibition of the enzyme by these reagents was protected by addition of $NADP^+$ whereas it was not affected by that of glucose-6-phosephate indicating that essential -SH and guanidino group are located on the $NADP^+$ binding region of active site. $Mg^{++}$ promoted the inhibition of the enzyme by the -SH and guanidino group directed reagents. But the promotion of the inhibition was considerably recovered in the presence of EDTA. This results suggested that divalent metal cation may affect the conformational change toward the susceptible one against modifying reagents.

Rhizobium trifolii Malonyl - CoA Synthetase 의 촉매반응에 관여하는 아미노산 Residue 의 화학변형

이상철,김유삼 ( Sang Chul Lee,Yu Sam Kim ) 생화학분자생물학회 1993 BMB Reports Vol.26 No.3

Malonyl-CoA synthetase from Rhizobium trifolii was inactivated by 2,3-butanedione and diethylpyrocarbonate (DEP). In each case, inactivation followed pseudo first-order kinetics. The second-order rate constant for the inactivation by 2,3-butanedione was 17.4M^(-1)·min^(-1) at pH 8.0, 30℃. DEP rapidly inactivated the enzyme with the second-order rate constant, 780 M^(-1)·min^(-1) at pH 7.1, 30℃. The reaction order of inactivation with respect to reagents were 1.06 and 1.03 respectively. The substrate, ATP, afforded the protection against the inactivation of the enzyme caused by the reagent, respectively. These results indicate that arginine and histidyl residues essential for the enzyme activity are located at or near the ATP binding region of the active site.

분석자동화를 위한 용액 조제 시스템 설계에 관한 연구

이상철,강성준,정양희,Lee, Sang-Chul,Kang, Seong-Jun,Joung, Yang-Hee 한국전자통신학회 2013 한국전자통신학회 논문지 Vol.8 No.7

석유화학 단지에서는 보다 완성도 높은 제품을 위한 많은 연구 개발이 진행되고 있으며 이 과정에서 제품의 중간 및 완성 제품에 대한 분석은 필수적이다. 그러나 이와 같은 분석 작업들이 아직도 많은 부분에서 수작업에 의한 분석 시료가 제조되고 있고 위험한 화학물질에 노출되어 열악한 환경에서 분석이 이루어지고 있다. 본 연구에서는 이와 같은 문제점을 해결하기 위하여 분석 자동화를 위한 멀티 제어 시스템을 개발하였다. 또한 이들 장치의 유기적인 동작과 자동화를 위한 프로그램을 개발하여 적용하고 이들 장치의 신뢰성 검증을 위한 실험을 통하여 표준 용액 조제를 위한 정량 펌프의 정확도가 ${\pm}0.01m{\ell}$의 오차 범위를 갖는 매우 우수한 결과를 얻을 수 있었다. Petrochemical complex has been a lot of research for the development of a more mature product and analysis for mid-process and finished products is essential in these process. But these analyzes are still by hand work samples being manufactured in many parts. Moreover they are exposed to hazardous chemical and such as the analysis is being made in a very poor working conditions. In this paper, in order to solve such problems the multi control system has been developed for the automated analysis. In addition, the organic behavior of these systems and the development of a program for the automated applied, and throughout the experiment to verify the reliability of this device for the accuracy of the dosing pumps for the standard solution prepared with a range of error of ${\pm}0.01m{\ell}$ was able to get a very good experimental results.

In Vitro Translation of Glucose-6-Phosphate Dehydrogenase Isozyme mRNA and In Vivo Isotope Labeling of the Enzyme from Peking Duck

이상철,김유삼,Lee, Sang-Chul,Kim, Yu-Sam 생화학분자생물학회 1985 한국생화학회지 Vol.18 No.3

오리의 uropygial gland와 간에서 $poly(A)^+mRNA$를 분리하여 그들의 in vitro translation mixture로부터 pI 6.6인 glucose-6-phosphate dehydorgenase를 분리 하고 in vivo isotope labeling된 같은 효소를 분리하여 SDS polyacrylamide disc gel electrophoresis를 통하여 비교하였다. 그 결과 in vitro translation mixture로 부터 분리한 효소와 in vivo labeling된 효소는 그것이 uropygial gland의 것이거나 간의 것이거나 모두가 uropygial gland에서 직접 정제한 효소와 같은 크기임을 알 수 있었다. 이러한 사실은 uropygial gland에 존재하는 pI 6.6인 glucose-6-phosphate dehydrogenase가 갖는 효소적 특성은 소수의 아미노산의 차이에 기인하는 것으로 예측된다. One glucose-6-phosphate dehydrogenase with pI of 6.6 was isolated from in vitro translation mixture and was compared with in vivo isotopically labeled enzyme by SDS polyacrylamide gel electrophoresis. The molecular size of the enzymes, isolated by antibody prepared against the purified enzyme and protein A agarose, are very similar to each other. This result suggests that the specific catalytic properties of the enzyme from the uropygial gland may depend on the minor difference in amino acid sequence.

Pyridoxal-5'-Phosphate에 의한 Rhizobium trifolii Malonyl-CoA Synthetase의 화학변형

이상철,김유삼,Lee, Sang-Chul,Kim, Yu-Sam 생화학분자생물학회 1993 한국생화학회지 Vol.26 No.3

Pyridoxal-5’-phosphate가 Rhizobium tifolii에서 정제한 malonyl-CoA synthetase를 가역적으로 불활성화 하였다. 반응의 2차 속도상수는 pH 7.0, $30^{\circ}C$에서 $2975 M^{-1}{\cdot}min^{-1}$이었다. PLP에 의해 불활성화된 효소는 완충용액으로 희석하였을 때 가역적으로 활성을 회복하였으나, $NaBH_4$로 환원 후 희석한 효소는 활성을 회복하지 못하였다. PLP와 반웅 후 $NaBH_4$로 환원한 효소액은 325 nm에서 톡징적인 Schiff base의 홉광도 변화를 보였다. ATP가 PLP에 의한 효소의 불활성화를 저해하였다. 이러한 결과들은 malonyl-CoA synthetase의 ATP 결합부위나 그 주위에 효소활성에 필수적인 amine group이 존재함을 시사한다. Pyridoxal-5'-phosphate inactivated malonyl-CoA synthetase from Rhizobium trifolii reversibly. The second-order rate constant, $K_i$ was $2975 M^{-1}{\cdot}min^{-1} $ at pH 7.0, $30^{\circ}C$. Inactivation of malonyl-CoA synthetase by PLP was reversed by dilution but not after reduction with $NaBH_4$. The spectra of malonyl-CoA synthetase, inactvated by PLP and reduced by $NaBH_4$, showed a characteristic Schiff base absorption change at 325 nm. ATP protected the enzyme from inactivation by PLP. These studies indicated that an essential amine is located at or near ATP binding region of the enzyme active site.

Pyridoxal - 5 ' - Phosphate 에 의한 Rhizobium trifolii Malonyl - CoA Synthetase 의 화학변형

이상철,김유삼 ( Sang Chul Lee,Yu Sam Kim ) 생화학분자생물학회 1993 BMB Reports Vol.26 No.3

Pyridoxal-5`-phosphate inactivated malonyl-CoA synthetase from Rhizobium trifolii reversibly. The second-order rate constant, K_i was 2975 M^(-1) · min^(-1) at pH 7.0, 30℃. Inactivation of malonyl-CoA synthetase by PLP was reversed by dilution but not after reduction with NaBH₄. The spectra of malonyl-CoA synthetase, inactvated by PLP and reduced by NaBH₄, showed a characteristic Schiff base absorption change at 325 nm. ATP protected the enzyme from inactivation by PLP. These studies indicated that an essential amine is located at or near ATP binding region of the enzyme active site.