슈퍼옥사이드 디스뮤타제가 우유의 리보플라빈 감광에 의한 광산화에 주는 영향+

이상화 서원대학교 응용과학연구소 1996 응용과학연구 Vol.5 No.1

To study the effect of superoxide dismutase (SOD) on riboflavin-sensitized oxidation, the samples of milk containing 0, 10, 20, and 30 U/ml SOD and 50 ppm riboflavin were prepared. Fifty ml of the sample was transferred into a 100ml serum bottle. The samples sealed were placed in the light storage box (light intensity=5,000lux) for 6 days at 5℃. Superoxide anion produced was determined by the nitrogen blue tetrazolium reduction method. The oxidative stabilies of milk lipid were studied by measuring TBA (thiobarbituric acid) value and depleted headspace oxygen (DHO) of sample bottles using G.C. everyday for 6 days. As the storage time increased, superoxide anion formation, TBA value, and DHO of milk with 50 ppm riboflavin significantly (P<0.05) increased under light. However, the TBA value of riboflavin-free milk did not change as the storage period increased under dark or light. The effects of different levels of SOD on the superoxide anion formation, TBA value, and DHO of milk were significantly different. (P<0.05). The combined results indicated that SOD reduced the riboflavin-sensitized photooxidation of milk.

Ilmenite로부터 Ti製鍊에 관한 基礎硏究(Ⅰ)

李相和 동아대학교 공과대학 부설 한국자원개발연구소 1989 硏究報告 Vol.13 No.2

This study has been performed to find out the reaction behaviour of ilmenite(FeTiO₃)-Na₂CO₃ mixtures in a atmosphere of CO₂+O₂ mixtures. The results obtained from the experiment are as follows ; 1) It has been found that the reactions of FeTiO₃-Na₂CO₃ system with respect to stoichiometric ration produce the complex compounds, Na_(6)Ti₂O_(7) and Na₂Ti₃O_(7), and these compounds have the melting point of 1080℃ and 1450℃ respectively. 2) Chemical analysis has shown that Ti-Na compound and Fe₂O₃ are seperated from ilmenie by Na₂CO₃ additions. 3) The experiment has shown that the growth of the compund produced form Ti-Na system occurs at high temperature.

낙동강 하구의 부유사 확산에 관한 수치모델 개발연구

이상화,김재중 동아대학교 환경문제연구소 1990 硏究報告 Vol.13 No.2

The concentration of suspended load is determined by the circulation of water and the material diffusion. The equations of the two-dimensional, depth-integrated dispersive transport are momentum equation, continuity equation, and diffusion equation based the Fick's law. The numerical model is made up two models which re flow and diffusion. The flow model is solved by the explicit scheme, The diffusion model is solved by multi-operational scheme. The open boundary condition is given as tidal water elevation estimated by using constituents. When suspended load concentration is estimated, the settling velocity is given as a function of concentration.

삶의 태도와 도덕적 선택 : Wuthering Heights의 경우- The Portrait of a Lady와의 비교연구

李相華 中央大學校 人文科學硏究所 1989 人文學硏究 Vol.16 No.-

Walter Ailen은 Emily Brontë가 그리는 세계는 ‘a spiritual world'로서 그곳에는 ’spiritual reality'가 있으며 Henry James의 세계는 일차적으로 ‘psychological reality'라고 말한 바 있다. 두 작가가 다루고 있는 현실은 다르지만 인간의 삶을 영위하는 태도와 방법을 개인적으로 또는 사회적으로 도덕적 선택의 문제와 결부시키면서 불변의 지속적 가치를 묻고 추구한 노력은 다르지 않다. 그들은 당연히 동일한 해결에 도달하고 있지는 않다. 그들이 살았던 시대가 다르고 그들 개인 및 그들의 사회의 가치가 다르고 그들이 중점을 두는 인간의 모습이 다르기 때문이다. 인간관계는 어떤 경우라도 인간의 삶의 씨줄과 낱 줄을 형성하고 내적 외적인 바탕을 이룬다. 그리고 그것은 어김없이 포괄적으로 시대적 사회적 함축을 갖는다. 한 세대를 격한 19세기의 두 작품 Wuthering Heights와 The potrait는 다 같이 그들의 시대가 만들어준 상황 속에서 인간관계와 존재의 법칙을 극적으로 제시해 주고 있다. 그러나 물론 두 작품 다 그 협소한 공간을 가능한 한 초월해서 존재하려고 한다. 삶의 문제와 도덕의 문제는 모든 시대와 모든 사회의 중심을 관통하는 생명운동이다. 그리고 소설을 구성하는 체험인 창작의 체험은 Raymond Williams의 말처럼 ‘a more than personal desire, a more than personal longing'인 것도 이들 두 작품의 성취에서 우리는 읽어낼 수 있다.

CosExp와 CosGauss 활성화 함수를 사용한 감독자 학습 알고리즘의 최적화

이상화 서원대학교 미래창조연구소 2004 과학과 문화 Vol.1 No.1

Cascade-Correlation is a supervised learning algorithm that automatically determines the size and topology of the network. Cascade-Correlation adds new hidden units one by one and creates a multi-layer structure in which each hidden layer has only one unit. By second order Cascade-Correlation, new hidden units are added to only one hidden layer. These created units are not connected to each other. We present a generalization of the Cascade-Correlation-Architecture by combining the standard Cascade-Correlation-Architecture and the second order Cascade-Correlation- Architecture. Whenever a hidden unit has to be added, the new Cascade-Correlation learning algorithm automatically determines whether the network topology grows vertically or horizontally. This new algorithm using sigmoid, tanh and new activation functions was tested with the sonar-benchmark-problem and the glass-benchmark-problem.

국영문(國英文) 화재보험보통약관의 면책사항(免責事項)에 관한 비교고찰

이상화 한국보험학회 1986 保險學會誌 Vol.28 No.-

보험요율의 자유화와 그 대응방안 : 손해보험요율을 중심으로 With Special Reference to our Non-Life Insurance Rates

이상화 한국보험학회 1997 保險學會誌 Vol.50 No.-

빛이 시금치의 클로로필 분해에 주는 영향

이상화 서원대학교 응용과학연구소 2002 응용과학연구 Vol.11 No.1

To improve the chlorophyll stability in spinach, effects of light on degradation of chlorophyll in spinach were studied.. The chlorophylls of spinach were extracted using organic solvents, and the components of chlorophylls were determined quantitatively and qualitatively. As the light intensity increased from 0 lux to 5,000 lux during storage, the contents of chlorophyll a and chlorophyll b in spinach decreased. The stabilities of chlorophyll in spinach processed and stored in light conditions were less than those in samples in dark conditions.

하악 구치부에 식립된 Br${\aa}$nemark 임프란트와 ITI 임프란트에서 임프란트간 치조정간골의 높이변화에 대한 방사선학적 비교

이상화,차인호,심준성,한동후,Yi, Sang-Hwa,Cha, In-Ho,Shim, June-Sung,Han, Dong-Hoo 대한치과보철학회 2004 대한치과보철학회지 Vol.42 No.4

Statement of problem: Br${\aa}$nemark or ITI are two currently most widely used implant systems but with contrasting design, surgical and restoration methods. Purpose: The purpose of this study was to compare changes and its statistical significance in bone height and shape which may rise due to the differences between two implant systems. Also to analyse the effect of inter-implant distance on annual bone height changes. Material & Method: Those patients who were treated with two or more of either Br${\aa}$nemark or ITI implants at posterior mandibular area at Yonsei University Dental Hospital, Implant Clinic were selected. At annual examination appointments, standardised radiographs using parallel technique were taken. Marginal bone and inter-implant crestal bone changes were measured and following results were obtained. Results: 1) When ITI and Br${\aa}$nemark system were compared, both annual marginal and inter-implant crestal bone height changes in ITI system in the first two years were smaller than Br${\aa}$nemark and they were statistically significant. On the third year, however, there was no statistical difference between two implant systems on their annual bone level changes (p>0.05). 2) The Marginal and inter-implant crestal bone changes were compared when inter-implant distance was less than 4mm. Statistically significant bone level changes were noted on the first year only for ITI implants but in the first and second year for Br${\aa}$nemark implants (p>0.05). 3) When comparing angulation changes between marginal bone and implant fixture, ITI system had smaller angulation changes but the annual changes were not statistically significant (p>0.05). Conclusion: Within the limitation of this study, it could be concluded that Br${\aa}$nemark implant systems had more changes in marginal and inter-implant crestal bone level in the first and second year after loading with statistical significance. Further studies are recommended to see the effects of these bone loss during the first and second year after loading on the long term prognosis of Br${\aa}$nemark Implants.

다원주 주위의 유동에 관한 실험적 연구

이상화,장은철 東亞大學校 海洋資源硏究所 2005 硏究論文集 Vol.17 No.-

원형 실린더 주위 유동에 대한 왕복 운동의 조사 방법은 3가지가 있는데 i) 고정 실린더에 파를 발생시키는 방법, ii) 정지 유체 내에서 실린더를 진동 시키는 방법, iii) U자 관내에서 유체를 공진 시키는 방법이 있다. 본 논문에서는 정지 유체 내에서 왕복 운동으로 다원주 진동에 의한 유도 현상은 가시화를 통하여 나타내었다. Vortex wakes는 Keulegan-Carpenter(KC) 수에서 고찰되었는데 그 범위는 8에서 48사이 이다. 그리고 KC와 더불어 원주의 직경과 배치에 따라서 여러 특징이 조사되었다. The sinusoidal motion for flow around the circular cylinder has been generated in three ways; i) placing a fixed cylinder under wave generating, ii) oscillating a cylinder in still fluid, iii) using the resonance of the fluid in U-tube. In this paper the flows induced by multi-circular cylinders performing sinusoidal oscillations in still fluid are indicated by means of visualization. Vortex wakes are presented at Keulegan-Carpenter number(KC) in the range 8 to 48. The variations with the cylinder spacing, diameter as well as the KC number were investigated.