석유개발정책

유창훈,Yu, Chang-Hun 대한석유협회 1993 석유와 에너지 Vol.1993 No.5

Column_대한민국세계여성발명대회 - 2010 대한민국세계여성발명대회 성공과 여성발명의 힘

유창훈,Yu, Chang-Hun 한국발명진흥회 2010 發明特許 Vol.35 No.8

웹 페이지에서 사용자 입력 값 변조 방지에 관한 연구

유창훈(Chang-hun Yu),문종섭(Jong-sub Moon) 한국정보보호학회 2014 정보보호학회논문지 Vol.24 No.4

인터넷을 통하여 제공되는 대부분의 웹 서비스들은 웹 브라우저를 통하여 사용자에게 제공된다. 웹 브라우저는 텍스트 형태의 웹 페이지를 서버로부터 수신하여 해석하고 사용자에게 보여준다. 웹 브라우저는 추가적으로 설치 할 수 있는 각종 기능들을 통하여 확장성을 제공한다. 하지만 추가로 설치 할 수 있는 기능들도 웹 페이지에 접근하여 내용을 위/변조 할 수 있다는 점에서 웹 브라우저를 통한 웹 서비스는 보안상 문제점을 내포할 수 있다. 웹 브라우저는 웹 페이지 정보를 DOM구조의 형태로 메모리에 저장한다. 웹 페이지의 변조를 방지하기 위한 방법으로는 DOM구조의 특정 부분에 해쉬(hash)값을 적용하는 방법이 있다. 하지만 웹 페이지의 특성상 해쉬를 이용한 대응방안이 효과를 발휘할 수 없는 부분이 있다. 즉, 사용자가 직접 입력하는 부분은 정해진 입력 값이 아니기 때문에 미리 해쉬 값을 계산 해 놓을 수도 없고 따라서 임의로 변조되는 것을 막을 수 없다. 본 논문에서는 웹페이지에 입력되는 사용자 입력 값의 위조나 변조를 방지 또는 탐지하는 방안을 제안한다. 제안 방법은 사용자가 키보드를 사용하여 입력하는 입력 값을 저장 해 놓았다가 웹 브라우저가 입력 값을 전송하는 순간 저장된 입력 값과 전송되는 값을 비교하여 변조 여부를 파악한다. Most of the web-based services are provided by a web browser. A web browser receives a text-based web page from the server and translates the received data for the user to view. There are a myriad of add-ons to web browsers that extend browser features. The browser’s add-ons may access web pages and make changes to the data. This makes web-services via web browsers are vulnerable to security threats. A web browser stores web page data in memory in the DOM structure. One method that prevents modifications to web page data applies hash values to certain parts in the DOM structure. However, a certain characteristic of web-pages renders this method ineffective at times. Specifically, the user-input data is not pre-determined, and the hash value cannot be calculated prior to user input. Thus the modification to the data cannot be prevented. This paper proposes a method that both detects and inhibits any attempt to change to user-input data. The proposed method stores user-input from the keyboard and makes a comparison with the data transmitted from the web browser to detect any anomalies.

고체분산체에 의한 펠로디핀의 용출율 개선과 서방성 경구제제

길영식,홍석천,유창훈,신현종,김종성,Gil, Young-Sig,Hong, Seok-Cheon,Yu, Chang-Hun,Shin, Hyun-Jong,Kim, Jong-Sung 한국약제학회 2002 Journal of Pharmaceutical Investigation Vol.32 No.3

To improve the solubility of poorly water-soluble drug and to develop a sustained release tablets, the need for the technique, the formation of solid dispersion with polymeric materials that can potentially enhance the dissolution rate and extent of drug absorption was considered in this study. The 1:1, 1:4, and 1:5 solid dispersions were prepared by spray drying method using PVP K30, ethanol and methylene chloride. The dissolution test was carried out at in phosphate buffer solution at $37^{\circ}C$ in 100 rpm. Solid dispersed drugs were examined using differential scanning calorimetry and scanning electron microscopy, wherein it was found that felodipine is amorphous in the PVP K30 solid dispersion. Felodifine SR tablets were prepared by direct compressing the powder mixture composed of solid dispersed felodipine, lactose, Eudragit and magnesium stearate using a single punch press. In order to develop a sustained-release preparation containing solid dispersed felodipine, a comparative dissolution study was done using commercially existing product as control. The dissolution rate of intact felodipine, solid dispersed felodipine and its physical mixture, respectively, were compared by the dissolution rates for 30 minutes. The dissolution rates of felodipine for 30 minutes from 1:1, 1:4, 1:5 PVP K30 solid dispersion were 70%, 78% and 90%. However, dissolution rate offelodipine from the physical mixture was 5% of drug for 30 minutes. Our developed product Felodipine SR Tablet showed dissolution of 17%, 50% and 89% for 1, 4, and 7 hours. This designed oral delivery system is easy to manufacture, and drug releases behavior is highly reproducible and offers advantages over the existing commercial product. The dissolution rate of felodipine was significantly enhanced, following the formation of solid dispersion. The solid dispersion technique with water-soluble polymer could be used to develop a solid dispersed felodipine SR tablet.

Biological monitoring of residents in abandoned metal mine areas

Young-Seoub Hong(홍영습),Chang-Hun You(유창훈),Geong-Yeon Kim(김경연),Byoung-Gwon Kim(김병권),Yu-Mi Kim(김유미) 환경독성보건학회 2012 한국독성학회 심포지움 및 학술발표회 Vol.2012 No.10

K-Log Block을 이용한 신뢰성 있는 마운팅 및 빠른 복구 기법

정승완(Jung Seung Wan),유창훈(Yu Chang Hun),서대화(Seo Dae-Wha) 한국통신학회 2011 한국통신학회 학술대회논문집 Vol.2011 No.2

연구논문 : 생명과학 ; 인간에서의 경구흡수를 촉진하는 투명 아세클로페낙 연질캅셀의 개발

용철순 ( Chul Soon Yong ),오유경 ( Yu Kyoung Oh ),이경희 ( Kyung Hee Lee ),박상만 ( Sang Man Park ),길영식 ( Young Sig Gil ),유창훈 ( Chang Hun Yu ),김종오 ( Jong Oh Kim ),유봉규 ( Bong Kyu Yoo ),이종달 ( Jong Dal Rhee ),김종국 ( 영남대학교 약품개발연구소 2005 영남대학교 약품개발연구소 연구업적집 Vol.15 No.-

50세 이상 및 중등도 이상 무지 외반증 환자에서의 원위 갈매기형 절골술

유원준(Won Joon Yoo),정문상(Moon Sang Chung),백구현(Goo Hyun Baek),유창훈(Chang Hun Yu),문혁주(Hyuk Ju Moon) 대한정형외과학회 2008 대한정형외과학회지 Vol.43 No.4

목적: 50세 이상 환자에서 중등도 이상의 무지 외반증에 대한 원위 갈매기형 절골술의 임상적, 방사선학적 결과를 분석하였다. 대상 및 방법: 중등도 이상의 무지 외반증 변형에 대해 원위 갈매기형 절골술을 시행받은 50세 이상(평균 58세)의 환자 19명, 26 족부를 대상으로 하였다. 추시 기간은 평균 3년 1개월이었다. 수술 전, 수술 후 6주, 그리고 최종 추시 시의 무지 외반각, 제 1-2중족골 간 각의 변화를 측정하였고, 교정각의 소실과 관련되는 방사선학적 인자에 대해 분석하였다. 임상적으로는 통증, 일상생활 활동능력 및 신발 착용의 변화를 분석하였다. 결과: 무지 외반각과 제 1-2중족골간 각은 비교적 만족스럽게 교정되었다. 그러나 수술 후 6주에 비해서는 교정각 소실을 보였으며 이는 수술 전 제 1중족 족지 관절의 아탈구 정도 및 제 1-2중족골 간 각과 유의하게 관련되었다. 임상적으로 통증과 일상 생활 활동 능력은 현저하게 개선되었으나 수술 후 편한 신발 대신에 딱딱한 구두를 신고 생활하는 환자는 5예에 불과하였다. 결론: 원위 갈매기형 절골술은 임상적으로 50세 이상 환자에서 중등도 이상의 무지 외반증의 치료에 유용하였다. 그러나, 수술 전 제 1중족 족지 관절의 아탈구가 심하거나 중증의 변형에서는 추시에 따라 상당한 교정 소실이 발생함에 유의하여야 한다. Purpose: The purpose of this study was to analyze the clinical and radiological results of distal chevron osteotomy in patients aged 50 and older with moderate-to-severe hallux valgus. Materials and Methods: The authors reviewed the medical records and radiographs of 19 patients (26 feet). Average age at time of surgery was 58 years and the mean follow-up period was 3 years and 1 month. For radiological evaluation, we analyzed changes in hallux valgus angles and 1<SUP>st</SUP>-2<SUP>nd</SUP> intermetatarsal angles after index operations. Clinical results were assessed with respect to pain, activities of daily living, and shoe-wear. Results: Hallux valgus angles and 1<SUP>st</SUP>-2<SUP>nd</SUP> intermetatarsal angles improved, but considerable correction loss occurred with time. This correction loss was found to be significantly correlated with preoperative subluxation of the 1st metatarsophalangeal joint and the 1<SUP>st</SUP>-2<SUP>nd</SUP> intermetatarsal angle. Clinically, remarkable improvements were achieved in terms of pain and level of activity, but most patients (except 4) still wore comfortable shoes rather than hard shoes at latest follow-ups. Conclusion: Distal chevron osteotomy is beneficial for patients aged 50 and older with moderate-to-severe hallux valgus deformity, but correction loss may occur in patients with marked subluxation of the 1<SUP>st</SUP> metatarsophalangeal joint or a severe 1<SUP>st</SUP>-2<SUP>nd</SUP> intermetatarsal angle.

L-아르기닌 복합체를 이용한 피록시캄의 용해도 및 생체이용률의 증가

홍석천,유창훈,조동현,신현종,길영식 한국약제학회 2003 Journal of Pharmaceutical Investigation Vol.33 No.2

Piroxicam-arginine complex was prepared to improve the solubility and dissolution rate of poorly water-soluble piroxicam. Its formation was identified by infrared spectrophotometry, differential thermal analysis and dissolution rate. Piroxicam complex dispersible tablets, commercial Feldene^?? dispersible tablets and piroxicam physical mixture hard capsules were prepared to compare dissolution rate in water. Dissolved amounts (%) after 15 mins of piroxicam complex dispersible tablets, commercial Feldene^?? dispersible tablets and piroxicam physical mixture hard capsules were 98%, 45% and 10%, respectively. The solubility of complex in water was significantly higher than that of piroxicam itself. In vivo, pharmacokinetic parameters were obtained after oral administrations of piroxicam complex and physical mixture at a does of 2㎎ to New Zealand White Rabbit. The C_max of piroxicam complex was similar to that of piroxicam. However, there were much difference between the two formulations with regard to T_max and AUC. The T_max of piroxicam alone was 4 hours, but that of piroxicam complex was 0.8 hours. In addition, the AUC of piroxicam complex was 1.38 times greater than that of piroxicam alone.

고체분산체에 의한 펠로디핀의 용출을 개선과 서방성 경구제제

길영식,홍석천,유창훈,신현종,김종성 한국약제학회 2002 Journal of Pharmaceutical Investigation Vol.32 No.3

To improve the solubility of poorly water-soluble drug and to develop a sustained release tablets, the need for the technique, the formation of solid dispersion with polymeric materials that can potentially enhance the dissolution rate and extent of drug absorption was considered in this study. The 1:1, 1:4, and 1:5 solid dispersions were prepared by spray drying method using PVP K30, ethanol and methylene chloride. The dissolution test was carried out at in phosphate buffer solution at 37℃ in 100 rpm. solid dispersed drugs were examined using differential scanning calorimetry and scanning electron microscopy, wherein it was found that felodipine is amorphous in the PVP K30 solid dispersion. Felodifine SR tablets were prepared by direct compressing the powder mixture composed of solid dispersed felodipine, lactose, Eudragit and magnesium stearate using a single punch press. In order to develop a sustained-release preparation containing solid dispersed felodipine, a comparative dissolution study was done using commercially existing product as control. The dissolution rate of intact felodipine, solid dispersed felodipine and its physical mixture, respectively, were compared by the dissolution rates for 30 minutes. The dissolution rates of felodipine for 30 minutes from 1:1, 1:4, 1:5 PVP K30 solid dispersion were 70%, 78% and 90%. However, dissolution rate offelodipine from the physical mixture was 5% of drug for 30 minutes. Our developed product Felodipine SR Tablet showed dissolution of 17%, 50% and 89% for 1, 4, and 7 hours. This designed oral delivery system is easy to manufacture, and drug releases behavior is highly reproducible and offers advantages over the existing commercial product. The dissolution rate of felodipine was significantly enhanced. following the formation of solid dispersion. The solid dispersion technique with water-soluble polymer could be used to develop a solid dispersed felodipine SR tablet.