반흔 조직에서의 Superoxide Dismutase 활성도에 관한 연구

조성인(Sung In Cho),서성준(Seong Jun Seo),홍창권(Chang Kwun Hong),노병인(Byung In Ro) 대한피부과학회 1994 대한피부과학회지 Vol.32 No.2

Background : Superoxide disrnutase(SOD) provides a protective defease mechanism against potential cytotoxicity of superoxide radical in the aerobic organism. Although human skin is constantly at risk for developing acute and chronic changes by ultraviolet radiation and phototoxic reactions with exogenous and endogenously procluced photosensitizing molecules, studies in SOD in the human skin are rare. Objective : We measured the level of SOD activities in the scar tissues and the normal human skin specimens. This study was to investigate changes of SOD activity by age, sex, and regional differences of SOD activities in the scar issues and the normal skin. Methods : Aut,hors assayed the level of SOD activit,ies in 32 scar tissues(male 8, female 24) and 11 normal human skin specimens(male 8, female 3), which were obtaine 3 from face/neck(17 and 3 specimens), forearm(only 4 scar tissues), trunk(10 and 8 specimens), and lower extremity(only 1 scar tissue). Results : First, activities of total SOD, Cu, Zn-SOD, and Mn-SOL ere 18.93+5.49, 16.97+55.31, and 1.96+0.90 units/mg proteiii respectively in the scar tissues. Second activities of total SOD, Cu, Zn-SOD, and Mn-SOD were 17.27+7.09, 13.82+6.44, and 3.45+1.07 units/mg protein respectively in the normal skin. Third, the changes of total SOD, Cu, Zn-SOD, and Mn-SOD activities by age and sex were similar each other and three were no significant, differneces between age groups in total, Cu, Zn- SOD, and Mn-SOD activities. Fourth, in sun exposed area and unexposed area there were no significant differences in the scar tissues in SOD activities. But, SOD activite.(total, Cu, Zn, and Mn-SOD) in face/neck were higher than those in trunk and lower extremity in tae normal skin(P<0.05). Conclusion : These findings suggest that there are no differences in the intrinsic SOD activities by age and sex in the mature scar tissues and the normal skin. Differences between exposed and unexposed area in the normal skin are due to the induction of exogenous SOD activity by sun-light generation of superoxide radicals. In wound, increased production of leukocyte derived superoxide radicals is the main factor of increased level of SOD activity. (Kor J Dermatol 1994; 32(2): 277-285)

불황기에서 회계정보에 의한 기업 부실화 예측

조성표(Seong-Pyo Cho),류인규(In-Gyu Ryu) 한국산업경영학회 2007 經營硏究 Vol.22 No.1

  기업부실예측에 대한 종전의 연구들은 기업의 내부 변수만 이용할 뿐, 경기변동 등 외부변수를 고려하지 않았다. 본 연구는 기업의 부실예측 요인이 경기변동에 따라 달라지는가를 실증 분석하였다. 이를 위하여 다양한 경기순환과정을 경험한 1993년 1월부터 1998년 10월 사이에 부실화 된 상장기업 148개를 표본으로 선정하고, 이와 비교하기 위해 부실기업과 같은 업종에 속하는 건전기업을 1:3의 비율로 대응시켰다. 재무비율로는 영업활동현금흐름, 차입금의존도, 당기순이익률, 당좌비율, 경영자본회전률, 기업규모를 t-검증, 로짓분석에 적용하였다. 또한 경기시점별로 불황기를 하락기(1996년 1월~1997년 9월), 위기기(1997년 10월~1998년 1월), 지속기(1998년 2월~10월), 그리고 불황이 시작되기전 호황기(1993년 1월~1995년 12월)로 구분하여 기업부실화 예측모형의 요인이 달라지는지 분석하였다. 분석 결과, 기업부실화 예측모형에서 부채비율, 현금흐름, 그리고 활동성, 기업규모가 유의적인 것으로 나타났다. 기업 부실화 요인은 경기시점별로 차이가 있었는데, 경기 하락기에는 부채비율과 활동성, 수익성이, 위기기에는 부채비율과 기업규모와 현금흐름이, 지속기에는 부채비율과 현금흐름이, 그리고 호황기에는 현금흐름이 유의적으로 나타났다. 부실화 시점에 따라 유의적인 변수가 달리 나타난 것은 경기가 가진 특성 중의 하나인 시중의 자금사정여부에 따른 것으로 생각된다. 또한 예측정확도에서 1종오분류율이 하락기에는 낮게 나타난 반면 위기기와 지속기에는 높게 나타났다. 이는 하락기에는 부채비율이나 수익성 등 재무적 정보만으로 부실 예측이 용이한 반면, 경기가 위기 상태로 악화된 경우에는 재무적 정보만으로는 부족하며, 외부환경변수 등 다른 비재무적 정보가 추가적으로 필요함을 알 수 있다. 본 연구는 부실화 시기를 분석에 명시적으로 도입하였고, 경기 상황에 따라 부실화 원인이 다름을 규명하였다는 데에 그 의의를 찾을 수 있을 것이다.   This study presents some empirical results of a study predicting corporate failure during a recession using financial ratios. The sample consisted of 148 failed firms and 421 nonfailed firms from listed companies. Logit model was composed of an intercept and the six independent variables: cash flow from operation to total assets, debt to equity, net income to sales, quick ratio, management capital turn over, and firm size. One distinguishing feature of this study is that significant factors in the prediction models were estimated across the evolution of recession: initial recession (January 1996 ~ September 1997), panical recession(October 1997 ~ January 1998), sustained recession(February ~ October 1998). The results of recession were compared with those of economic boom(1993~1995). The results indicated that the four factors derived from financial statements were statistically significant for purpose of assessing the probability of corporate failure. They were debt to equity, cash flow from operation, turn over ratio, and firm size. In all subperiods, the ratio of debt to equity appeared as an most important factor. Significant factor were different for each subperiod which were: debt to equity, cash flow from operation, turn over, and net income ratio of the firms failed in the initial recession; debt to equity, firm size, and cash flow from operation of those in panical recession; debt to equity, cash flow from operation of those in sustained recession; cash flow from operation of those in economic boom. The difference seemed to be caused due to the currency condition of the period. Prediction error, especially Type I error, was much less in initial recession than panical and sustained recession, which suggested that non-financial data need to be supplemented in the model predicting the firms failed in the panical and sustained recession.

배양된 정상 인체 각질형성세포에서 자외선 B 조사에 의한 아포프토시스와 p53의 발현

김명남(Myeung Nam Kim),서성준(Seong Jun Seo),홍창권(Chang Kwun Hong),노병인(Byung In Ro),노성욱(Sung Wook Ro),조성인(Sung In Cho) 대한피부과학회 2000 대한피부과학회지 Vol.38 No.4

N/A Cutaneous absorption of ultraviolet B(UVB) in the skin occurs primarily in keratinocyte, causing DNA and protein damage. p53 tumor suppressor gene appeared in the epidermis after UVB irradiation, and the wild type has been known to be responsible for apoptosis and plays an important role in excluding abnormal cells with significant DNA damage. While p53 has been implicated in both DNA repair and apoptosis, it is unclear whether the p53 protein is involved in both of these processes within the same cell. Therefore, UVB-induced apoptosis and changes in p53 expression were studied in cultured normal human keratinocyte to determine that the cellular response to UVB induced DNA damage(DNA repair or apoptosis) correlated with p53 expression. The cultured normal human keratinocytes were irradiated with the doses of UVB(25-150 mJ/cm2) and incubated for various times(3, 6, 12, 24 hour) after radiation. At UVB doses of 100 and 150 mJ/cm2, acridine orange/ethidium bromide(Ao/Eb) staining-positive cells and TUNEL (TdT mediated dUTP-biotin nick end labeling) staining-positive cells increased significantly after 3 hours and 6 hours postirradiation respectively. Twelve hour postirradiation, staining-positive cells increased at each level of UVB-radiation exposure. These results suggest that there were significant influences of UVB doses and time course after irradiation to the number of Ao/Eb and TUNEL staining-positive cells. To determine whether all Ao/Eb and TUNEL-positive cells were actually undergoing apoptosis, cellular DNA was extracted from keratinocytes at 12 hours after UVB irradiation and seperated by electrophoresis on an 2.5% agarose gel to detect the internucleosomal DNA fragmentation(DNA ladder). 'DNA ladder' occurred at every dose of UVB 12 hour after irradiation, but did not appear early after irradiation, suggesting that whether Ao/Eb and TUNEL-positive cells observed early after irradiation were not undergoing apoptosis. Activation of p53 and the response to DNA damage is not observed universally, but is dependent on tissue specificity, species specificity and type of genotoxic damage. To correlate p53 level with UVB-induced apoptosis at the dose of 100mJ/cm2 UVB, p53 levels were determined by western blot analysis. The accumulation of p53 protein was apparent after 6 hours postirradiation, and UVB irradiation caused a dramatic increase in p53 levels at 12 and 24 hours. These results demonstrate that p53 is required for UVB-induced apoptosis in cultured normal human keratinocyte and p53 has a time-dependent effect in the initiation of apoptosis. In this study, the results indicated that a low dose(25mJ/cm2) of UVB irradiation could induce apoptosis in human keratinocyte in vitro and UVB exerts a time-dependent effect on inducing apoptosis. And the results also give support to increasing evidence that p53 may play a role in UVB-induced DNA damage and the induction of apoptosis in cultured normal human keratinocyte and that p53 is involved in the decision process which determines the fate of keratinocyte after UVB -induced DNA damage. (Korean J Dermatol 2000;38(4):481~489)

시설 재배 수박병 진단을 위한 전문가시스템의 개발

조성인(Cho Seong In),박은우(Park Eun Woo),이강걸(Lee Khang Keol),김승찬(Kim Seung Chan) (사)한국생물환경조절학회 1994 시설원예‧식물공장 Vol.3 No.1

상시불통형 p-GaN 게이트 전력반도체소자의 게이트층 계조화를 통한 전계 완화

조성인(Seong-In Cho),김형탁(Hyungtak Kim) 대한전자공학회 2020 대한전자공학회 학술대회 Vol.2020 No.8

표본조사에 의한 기업 연구개발활동 통계 작성방안

조성표 ( Seong Pyo Cho ),박선영 ( Sun Young Park ),한기인 ( Ki In Han ),노민선 ( Min Sun Noh ) 기술경영경제학회 2009 Journal of Technology Innovation Vol.17 No.2

본 연구에서는 국가의 연구개발활동조사에서 기업연구개발활동 통계에 대한 효과적인 산출방법을 제시하고자 하였다. 이를 위하여 국내ㆍ외 연구개발 통계 방법을 조사한 후 이를 토대로 우리나라에서 기업연구개발활동에 대한 자료의 수집 및 분석에 대한 개선방안을 제시하였다. 대부분의 국가에서 대기업은 전수조사, 소규모 기업은 표본조사를 수행하고 있으나, 우리 나라에서는 연구소 등록법인에 대하여 전수조사를 행하고 있다. 전수조사는 비용이 많이 들고 비표본오차로 인하여 모집단에 대한 체계적인 추정이 불가능하다는 문제점이 있다. 현재 산업기술진흥협회에 등록된 연구기관의 수가 20,000개를 넘어서고 있어 전수조사는 한계에 다다른 것으로 생각되어 표본조사 도입에 대한 타당성과 방법론을 중점적으로 검토하였다. 먼저, 표본조사의 타당성을 평가하기 위하여 현재 전수조사를 통해 수집된 자료를 이용하여 표본조사를 수행한 결과를 비교 분석하였다. 산업별(24개), 그룹별(8개)로 구분하여 216개 셀별로 모집단수/표본수를 곱하여 산정(셀별추정법)한 결과, 전수 통계치와 거의 동일하게 나타났다. 따라서, 산업별, 그룹별로 세분하여 모집단수/표본수를 곱하여 추정하는 셀별추정법이 타당한 것으로 평가할 수 있다. 이상의 분석결과를 토대로 조사설계 방안을 제시하면 다음과 같다. 직전연도 조사기업은 직전연도 연구개발비 수준과 기업종류(대기업, 벤처기업, 중소기업), 그리고 산업에 따라 셀을 분할한다. 대기업, 연구개발비 수준이 높은 기업 등 주요한 셀에 대하여는 전수조사를 실시한다. 나머지 셀에 대하여는 각 셀별 연구개발지출의 분포가 동질적이기 때문에 표본 추출방법은 단순임의추출법(SRS)을 사용한다. 다만 전년도 미계상된(또는 미포함된) 기업에 대하여는 신규 대형 연구소 진입 등을 고려하여 규모비례확률추출법(PPS)을 고려하는 것이 바직할 것으로 판단된다. 일부 기업들이 특정 항목에 대한 자료를 제공하지 않는 항목무응답의 경우, 누락된 자료에 대하여는 대체기법(Imputation Algorithm)에 따라 이를 추정한다. 이러한 표본조사방법은 전수조사에서 발생하는 비표본오차를 해소하고, 자료 수집비용 및 소규모기업의 행정적 부담을 경감할 수 있다는 장점이 있다. 향후 연구에서는 좀 더 구체적인 조사방법론을 강구할 필요가 있으며, 이와 함께, 연구개발에 대한 다양한 측면의 정보를 수집하기 위해 새로운 설문지를 개발할 필요성이 있다. The Survey on the Industrial Research and Development(R&D) is the primary source of information on R&D performed by Korea industrial sector. The results of the survey are used to assess trends in R&D expenditures. Government agencies, corporations, and research organizations use the data to investigate productivity determinants, formulate tax policy, and compare individual company performance with industry averages. Recently, Korea Industrial Technology Association(KOITA) has collected the data by complete enumeration. Koita has, currently, considered sample survey because the number of R&D institutions in industry has been dramatically increased. This study develops survey design for the industrial research and development(R&D) statistics by introducing a sample survey. Companies are divided into 8 groups according to the amount of R&D expenditures and firm size or type. We collect the sample from 24 or 8 sampling strata and compare the results with those of complete enumeration survey. The estimates from 24 sampling strata are not significantly different to the results of complete enumeration survey. We propose the survey design as follows: Companies are divided into 11 groups including the companies of which R&D expenditures are unknown. All large companies are included in the survey and medium and small companies are sampled from 70% and 3%. Simple random sampling (SRS) is applied to the small company partition since they show uniform distribution in R&D expenditures. The independent probability proportionate to size (PPS) sampling procedure may be applied to those companies identified as `not R&D performers`. When respondents do not provide the requested information, estimates for the missing data are made using imputation algorithms. In the future study, new key variables should be developed in survey questionnaires.

상시불통형 p-GaN/AlGaN/GaN 이종접합 트랜지스터의 게이트막 농도 계조화 효과

조성인(Seong-In Cho),김형탁(Hyungtak Kim) 한국전기전자학회 2020 전기전자학회논문지 Vol.24 No.4

본 연구에서는 상시불통형 p-GaN 전력반도체소자의 신뢰성 향상을 위해 p-GaN 게이트막 내부의 전계를 완화하고자 p-GaN 게이트 도핑농도의 계조화를 제안한다. TCAD 시뮬레이션으로 균일한 도핑농도를 갖는 소자와 문턱전압과 출력 전류 특성이 동일하도록 p형 농도를 계조화하고 최적화하였다. p-GaN 게이트층에서의 전계 감소로 소자의 게이트 신뢰성이 개선될 수 있을 것으로 판단된다. In this work, we proposed a graded gate-doping structure to alleviate an electric field in p-GaN gate layer in order to improve the reliability of normally-off GaN power devices. In a TCAD simulation by Silvaco Atlas, a distribution of the graded p-type doping concentration was optimized to have a threshold voltage and an output current characteristics as same as the reference device with a uniform p-type gate doping. The reduction of an maximum electric field in p-GaN gate layer was observed and it suggests that the gate reliability of p-GaN gate HFETs can be improved.

식품 금속검출기 개발에 관한 기초연구

조성인,강은,정창호,최낙진 ( Seong In Cho,Eun Kang,Chang Ho Chung,Nak Jin Choi ) 한국산업식품공학회 1997 산업 식품공학 Vol.1 No.2

정전용량을 이용한 산물벼의 함수율 측정장치 개발

조성인(Seong In Cho),정창호(Chang Ho Chung),김청월(Cheong Wol Kim) 한국산업식품공학회 2000 산업 식품공학 Vol.4 No.2

N/A

사망원인과 지역의 관련성에 관한 연구

조성인 ( Seong In Cho ),김병수 ( Byung Soo Kim ),전민수 ( Min Soo Jeon ) 한국보건정보통계학회(구 한국보건통계학회) 2014 한국보건정보통계학회지 Vol.39 No.2

Objectives: This study aims to examine the relation between the cause of death and the regions. Methods: It is examined what differences are in the cause of death based on regions and, if there are some differences, it is also examined in regard to regional characteristics focused on lift what the cause of death which has big differences is based on regions. Also, regional characteristics related to regional differences in the cause of death are traced out by using correlation coefficient. For the cause of death, the ones which are more than 10,000 among the ones which are applicable to the intermediate level for Korean Standard Classification of Diseases are examined and the regions are examined based on the unit of provincial governments and the one of municipal governments. Results: According to the result of analysis, lift for diabetes and suicide is the highest at Dongducheon-si and Siheung-si, respectively and it is also high at the regions where the rate of drinking alcohol and the one for early marriage and divorce are high. For the cause of death which has big differences based on regions, it is the death by heart disease as other systems and the lift is high at Gyeongnam regions. As a result of the correlation analysis performed for regional characteristics, correlation of variables for average temperature, the lowest temperature and the highest temperature is high. Also, probability to die of disease of respiratory system is high at the regions whose rate for the oldest is high. It is low at the regions with a great deal of precipitation. Conclusions: We discovered the fact that there are causes to be discrepant on the basis of probability to die by region, and we can make a conclusion that a part of causes to die have a relationship to each regional characteristics such as atmospheric temperatures.