신규 3작용성 메타크릴레이트의 치과용 광중합형 콤포짓트 레진용 단량체로서의 응용 연구

김중곤,정찬문,김민성,김광만,김경남 大韓齒科器材學會 2001 대한치과재료학회지 Vol.28 No.4

Tris[4-(2-hydroxy-3-methacryloxypropoxy)phenyl]methane(THMPM) was prepared easily from triphenylolmethane triglycidyl ether in good yield. As compared with composite resin formulated with difunctional bis-GMA, the physical properties of a newly developed composite resin formulated with trifunctional THMPM was evaluated. Cytotoxicity and acute toxicity of composite resin based on trifunctional THMPM evaluated according to ISO standard method. The depth of cure of the composite resin based THMPM was higher than that of the bis-GMA composite. There were no significant differences in flexural strength and water sorption between the composites resin based on THMPM and bis-GMA. The water-solubility value for the light-activated composite resins formulated with THMPM was much lower than that for a control bis-GMA composite. According to cytotoxicity evaluation, the composite resin based on THMPM showed very mild cytotoxicity with the response index of between 0/0 and 1/0. No acute toxicity of composite resin formulated with trifunctional THMPM was also observed. It is believed that THMPM is promising candidate for application as a photocurable dental composite resin.

유도 결합형 플라즈마에서 In-situ 플라즈마 전자밀도 측정방법 연구

정민중,김곤호 한양대학교 이학기술연구소 2002 이학기술연구지 Vol.5 No.-

유도 결합성 플라즈마 발생 장치에서 플라즈마 밀도를 측정하기 위한 In-Situ 플라즈마 진단 방법을 개발하였다. 안테나로 인가된 전력은 모두 플라즈마를 발생시키는데 소모되었다고 가정하여, 전력 균형식으로부터 안테나에 인가된 전력과 플라즈마 내부인자의 함수관계를 유도하고, 안테나 안가 전력의 전류와 전압을 측정하여 전자밀도를 유추할 수 있다. 안테나의 전류와 전압을 실시간으로 측정하는 전력측정 장치를 제작하고, 아르곤 가스를 이용하여 50, 40 및 30 mtorr의 운전 압력에서 인가 전력을 300- 800W로 바꾸어 가면서 실험하였다. 정전 탐침을 이용해서 반옹기 내부에서 직접 얻은 플라즈마 밀도와 안테나에 인가된 전력을 이용하여 측정된 전자밀도의 비율은 인가 전력에 무관하게 일정한 값을 보였으나, 운전 압력에 따라서 0.1 , 0.3 그리고 0.5의 값을 가졌다. 개발된 진단 방법이 운전 압력에 민감하나 플라즈마 밀도 변화를 정성적으로 관측할 수 있는 방법임을 보였다. In-situ plasma density monitoring system in an inductively coupled plasma source has been developed. Assuming the input power delivered only to the plasma generation, the relation between the delivery Power on the antenna and the plasma parameters can be obtained from the power balance equation. The in-situ system to monitor the current and voltage of the antenna was manufactured. Experiments were carried out under Ar gas pressures, 50, 40, and 30 mTorr with varying the rf power from 300 to 500w, respectively. Plasma parameters were measured directly by the electrical probe and compared to the results taken from the power monitoring system. The comparison shows that the power monitoring system was not sensitive to the input power but to the operating pressure. The system can beused monitor the qualitative behaviour of the plasma in the chamber .

X-관련성 만성육아종성질환의 진단을 위한 PMA-activated NBT 검사

김중곤,조한익,오흥범,김의종,최강원 대한감염학회 1996 감염 Vol.28 No.1

목적 : Activated NBT 검사는 만성육아종성질환을 선별하는 검사이다. 활성제로 PMA를 사용하면 X-linked CGD의 경우 보인자를 감별할 수 있다. 방법 : CGD의 가족력을 부인하는 정상인 30명을 대상으로 PMA activated NBT 슬라이드 검사를 실시하여, 정상대조에서의 formazan 형성율을 보았으며, 동일 검사를 CGD가 강력히 의심되는 환자와 그 가족에 대하여 실시하였다. 결과 : 정상대조 30명 전원에서 98% 이상의 formazan 형성세포가 관찰되었다. 환자에게 실시한 결과 세환자 모두에서 0%의 결과를 보였다. 환자의 어머니에서는 각각 57, 70, 67%의 결과를 보였다. 결론 : 본 연구를 통하여 세 환자는 X-관련성 만성육아종성질환이라는 진단을 내릴 수 있었다. PMA activated NBT 슬라이드 검사는 시행하기가 쉽고 재현성이 좋으므로, 어러 검사실에서 소아기 면역결핍증을 선별하는 검사의 하나로 시행되는게 바람직하다고 사료된다. Background : Chronic granulomatous disease(CGD) is uncommon inherited disorder in which phagocytic cells fail to produce antimicrobial superoxide(O₂) due to NADPH oxidase deficiency. This disease can be easily screened by activated nitroblue tetrazolium(NBT) test. In case of X-linked CGD, carriers also can be detected. Methods : PMA(phorbol myristate acetate) activated NBT test was performed as previously described. Test performance was evaluated in 30 normal persons who denied family history mimicking CGD. Test was also applied to the three strongly suspected cases of CGD. Two of the cases were 12 year old boy and 7 year old boy, who suffered from many infectious diseases since 6 month old and 4 month old, respectively. The other remaining case was 22 year old man who suffered from many infectious diseases since 6 year old, but now relatively in health compared to the other two cases. Results : More than 98% formazan formation was observed in all normal controls. No formazan positive cell was shown in all of the three patients. However, applied to the mothers, the test revealed 57%, 70%, 67% positive cells, respectively. Conclusion:X-linked transmission of CGD could be determined with the results of PMA activated NBT slide test. This test can be easily performed. It would be better to do this test routinely as one of the tests for the screening of the immmunodeficiency syndrome in childhood.

강산 및 강알칼리 음독에서 냉각 용액을 사용한 희석 요법과 중화 요법의 가능성

이중의,송형곤,김동훈,권운용,곽영호,서길준,윤여규 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

Background: There is no effective treatment modality for caustic agent ingestion. Dilution and neutralization are prohibited because of the risk of secondary thermal injury. This experiment is designed to evaluate the amount of dilution and neutralization heat and to gauge the applicability of dilution and neutralization therapy using cold solutions to suppress the peak temperature. Methods: This is an in-vitro chemical experiment. HCl, CH3COOH, NaOH, and NH4OH are selected as representatives of strong and weak acids and strong and weak alkali, respectively. 20℃, 11.6M, 5.8M, and 2.9M solutions of each acid and alkali are made and mixed using a magnetic stirrer at a room air temperature of 28℃. The peak temperature, the duration above 40℃, and the heat amount are measured or calculated. Results: When a 11.6M HCl or NaOH solution is diluted with same amount of water, 32 or 18cal. per mL of HCl or NaOH is produced, respectively. HCl produces a significant peak temperature, but NaOH does not. The lower the concentration, the lower the amount of heat production. 11.6M CH3COOH and NH4OH solutions don't produce dilution heat.11.6M and 5.8M solutions of all acids and alkali produce destructive neutralization heat. However, 2.9M solutions produce neutralization heat which might be controllable. When a 11.6M HCl or NaOH solution is neutralized with a -10℃ 2.9 M NaOH or HCl solution, respectively, the peak temperature produced is below 40℃ and seems to add little thermal damage to viable tissue. Conclusion: Dilution and neutralization with a cold solution in cases of strong acid or alkali ingestion is a promising method to avoid thermal injury.

영역분류를 이용한 블록화 현상 감소 기법

서용수,김중곤,김우열 東西大學校 2000 동서논문집 Vol.6 No.-

본 논문에서는 DCT(Discrete Cosine Transform)를 기반으로 정지영상을 압축한 후 복원된 영상의 블록화 현상을 감소시키기 위한 방법을 제안하였다. 제안한 블록화 현상 감소기법은 BCT 계수의 특성에 따라 단순영역과 복잡영역으로 분류한 후 분류된 영역에 따라 서로 다른 양자화 테이블을 적용시켰다. 인간시각 특성상 블록화 현상이 잘 나타나는 평탄영역과 단순에지 영역은 저주파 영역의 양자화 요소값을 작게 하여 블록화 현상을 감소시키고, 복잡 영역에서는 블록화 현상이 눈에 잘 나타나지 않기 때문에 양자화 요소값을 증가시켜 비트발생률을 줄일 수 있도록 하였다. 제안한 블록화 현상 감소 기법의 타당성은 컴퓨터 모의실험을 통하여 확인하였다. In this paper, we proposed a method of reducing blocking effects in reconstructed image that was compressed on DCT(Discrete Cosine Transform). The proposed blocking effects reduction techniques use difference quantization table according to region classification such as simple and complex region. The regions are classified by the characteristics of DCT coefficient. In flat and simple edge region, where blocking effects are more visible, we use small valued quantization table to reduce blocking effects. For complex region, blocking effects are less visible, we use large valued quantization table to reduce generated bit rate. Computer simulation results show that blocking effects of proposed method is reduced that of conventional method.

경계 방향 특성을 이용한 변위추정 기법

서용수,김중곤 東西大學校 2001 동서논문집 Vol.7 No.-

In this paper, we propose an efficient block based disparity estimation method which use the disparity vector of spatially adjacent blocks and edge orientation characteristics for the stereoscopic image. The proposed disparity estimation method calculates initial disparity vector at first, and then the final disparity vector is obtained by the full search disparity estimation for small search region. The method can obtain smoothed disparity vector in smooth region and can obtain a small error in the simple edge and texture region. An additional feature of this method is that its computational load decreased for calculating the disparity vector on account of estimating initial disparity vector and searching for smaller region. The simulation results demonstrate that disparity vectors are smoothed and PSNR is close to the one of full search.

원격감지 영상의 콘트라스트 향상

서용수,김중곤 東西大學校 2001 동서논문집 Vol.7 No.-

In this paper we discussed the processing procedures of histogram equalization(HE) method and brightness preserving hi-histogram equalization(BBHE) method in the contrast enhancement methods for the performance comparison. With remotely sensed image data of Landsat TM we compared the performances of four methods about Min-Max method, ± 1SD method, HE method, BBHE method. The simulation results demonstrate that the HE method and BBHE method are more effective in the contrast enhancement performances than the Min-Max method and ± 1SD method. In the HE method the mean brightness of the resultant output images approached to the middle gray level with regardless of input image mean. In the BBHE method, it is capable of preserving the mean brightness of a input image compared to the HE method while enhancing the contrast of input image effectively. Thus it is provided more natural enhancement effect than the HE method.

적외선 흡수 분광법 및 DPC를 이용한 치과용 수복재의 광중합 거동 분석

정찬문,김중곤,최준호,장두옥,김경남,김광만 대한치과기재학회 1998 대한치과재료학회지 Vol.25 No.1

Mechanical properties of compomers would be obtained mainly by photopolymerization by visible light irradiation. Photopolymerization behavior of two commercial compomers was investigated by FT-IR spectral analysis and differential photocalorimetry(DPC). The results obtained were as follows: 1. From FT-IR analysis, it was found that the compomer products were photocured mainly by radical polymerizations of multifunctional methacrylate monomers. Final conversion values of the polymerizations after exposure to visible light for 60 sec were 67% for Dyract and 59% for Compoglass. 2. Upon exposure the compomers exhibited autoacceleration and autodeceleration, which are usually observed in bulk polymerizations of multifunctional monomers. 3. Dyract showed higher rate of polymerization and conversion of double bond than Compoglass.

파라콰트 중독에서의 항산화치료

권운용,조유환,송형곤,김명천,이중의,서길준,윤여규 대한응급의학회 2001 대한응급의학회지 Vol.12 No.4

Background: Paraquat causes severe tissue toxicity when ingested, but has no effective treatment modality. We have shown that high dose vitamin C has effective antioxidant activities against the paraquat intoxication in a previous animal experiment. This study was designed to evaluate the effect of antioxidant therapy with high dose vitamin C and vitamin E in human cases of paraquat intoxication. Methods: From August 1999 to August 2001, 19 paraquat intoxication patients who visited the emergency department of the Seoul National University Hospital and the Kyounghee University Hospital were enrolled to this study. They were devided into two groups, a control group(9 patients) and a study group(10 patients). The control group received only conservative managements including gastro-intestinal decontaminati-on. The study group received conservative managements plus the antioxidant therapy which was composed of vitamin C 24 gm/day intravenously and 20 gm/day orally, and vitamin E 1.6 gm/day orally. Results: In the study group, 5 of 10 patients(50%) survived, but all patients of the control group died(p=0.003). There were no significant differences in age, sex, and usage of gastric lavage and activated charcoal between the two groups. Difference in ingested amount of paraquat between the two groups could not be analyzed due to the inexact and subjective measuring methods based on patients' histories. Conclusion: Antioxidant therapy with high dose vitamin C and vitamin E is effective in vival rate in paraquat intoxicated patients.

배달 미니 게임 개발:"최고의 웨이터를 꿈꾸며"

김정훈,정한교,김영옥,김중곤,박정윤,윤진성,김경식 호서대학교 반도체제조장비국산화연구센터 2001 반도체장비학술심포지움 Vol.2001 No.-

본 미니 게임은 웨이터라는 직업을 모티브로 하여서 남녀노소 누구나 재미를 느낌과 동시에 기억력 향상시켜 주는 게임제작이라는 목적아래 제작되었다.본 논문에서는 이 게임의 제작과정을 기술하고자 한다.이 게임은 제3회 AGC(한국 아마추어 게임제작 공모전)에서 우수 작으로 선정되었다.