Efficient Time Domain Aeroelastic Analysis Using System Identification

Hyek-Jun Kwon,Jong-Yun Kim,In Lee,Dong-Hyun Kim 한국항공우주학회 2005 International Journal of Aeronautical and Space Sc Vol.6 No.1

The CFD coupled aeroelastic analyses have significant advantages over linear panel methods in their accuracy and usefulness for the simulation of actual aeroelastic motion after specific initial disturbance. However, in spite of their advantages, a heavy computation time is required. In this paper, a method is discussed to save a computational cost in the time domain aeroelastic analysis based on the system identification technique. The coefficients of system identification model are fit to the computed time response obtained from a previously developed aeroelastic analysis code. Because the non-dimensionalized data is only used to construct the model structure, the resulting model of the unsteady CFD solution is independent of dynamic pressure and this independency makes it possible to find the flutter dynamic pressure without the unsteady aerodynamic computation. To confirm the accuracy of the system identification methodology, the system model responses are compared with those of the CFD coupled aeroelastic analysis at the same dynamic pressure.

프레드니솔론 시럽제 제제설계 및 안정성 연구

남택종,남궁형욱,김향숙,박광준,박경호,조남춘,이근혁 한국병원약사회 1999 병원약사회지 Vol.16 No.1

Prednisolone (PD) has been used in various disease and as various doses according to disease or body weight in pediatrics. Young children (≤5 years) who cannot able to take the tablet is prescribed with pulves, but the taste of PD is so bitter that they are difficulty in taking this medicine. And it is difficult to take precise doses because of the unequalization of distribution, loss of drug when it is distibuted with pulves. So in this study, we developed PD syrups for easiness, exactness of distribution and evaluated the stability of prednisolone syrups. First, we made an preliminary experiments to evaluate the effect of exipients on the stability. We added EDTA (disodium edetate) to PD solutions (0.05%) and observed the slight changes of the contents. As a result, EDTA has an effect of stabilization. Besides, after added 40% sucrose and preservatives to PD solutions (0.05%), mixed each 10% glycerin, sorbitol, xylitol, propylene glycol (PG), and preserved for 6 days at 55℃, we analyzed the contents and compared the rate constant (k) and half-life (t_(1/2)). Because solutions added PG, glycerin is more stable, we observed the stability of the different concentrations of these exipients and established the appropriate concentrations of these exipients. We kept PD solutions containing citric acid for 7 days at 55℃ and evaluated the effect of the concentration of the citric acid. As a result, there is no difference less than 0.5% citric acid concentrations. Second, through this preliminary experiments we designed the preliminary formulations. To examine the stability of formulations which is containing alcohol and is not, formulations containing alcohol (RP1, RP2) and formulations not containing alcohol (RP3, RP4) were stored for 4 weeks at 30, 40, 60℃ and was measured by a stability-indicating HPLC. And we plotted the Arrhenius-plot. All samples were analyed in duplicate on each week of analysis. When extrapolated this straight line, we found that the shelf life (t_(90)%) of RPI was about 23.4 months, RP2 was about 2.5 months, RP3 was months and RP4 was about 7.4 months. We developed PD syrups successfully but thought that we hereafter would correct the bitter taste of prednisolone itself.

동적 환경에서의 효과적인 움직이는 객체 추출

한재혁(Jae-Hyek Han),김용진(Yong-Jin Kim),유세운(Sae-Woon Ryu),이상화(Sang Hwa Lee),박종일(Jong-Il Park) 한국HCI학회 2009 한국HCI학회 학술대회 Vol.2009 No.2

컴퓨터 비전 분야에서 전경을 추출하기 위한 영역 분할(segmentation) 방법에 대한 연구가 활발히 진행되어 왔다. 특히, 전경이 배제된 배경 영상과 현재 프레임의 차이를 이용하여 전경을 추출하는 배경 차분(background subtraction) 방법은 요구하는 계산량에 비해 우수한 품질의 전경 추출이 가능하므로 실시간 처리가 필요한 비전 시스템에 다양하게 응용되고 있다. 그러나 배경 차분 방법만을 이용하여서는 배경이 동적으로 변하는 환경에서 정확한 전경을 추출해 내지 못하는 단점이 있다. 본 논문에서는 정적인 배경과 동적인 배경이 공존하는 환경에서 영역 분할을 효과적으로 수행하는 방법을 제안한다. 제안된 방법은 정적인 배경 영역에 대해서는 기존의 배경 차분방법을 이용하여 전경을 추출하고, 동적인 배경 영역에 대해서는 깊이 정보를 이용하여 전경을 추출하는 하이브리드 방식을 사용한다. 정적인 배경에 동적인 영상을 프로젝터로 투영하는 환경에서 제안된 방법의 효율성을 검증하였다. Foreground segmentation methods have steadily been researched in the field of computer vision. Especially, background subtraction which extracts a foreground image from the difference between the current frame and a reference image, called as "background image" have been widely used for a variety of real-time applications because of low computation and high-quality. However, if the background scene was dynamically changed, the background subtraction causes lots of errors. In this paper, we propose an efficient background subtraction method in dynamic environment with both static and dynamic scene. The proposed method is a hybrid method that uses the conventional background subtraction for static scene and depth information for dynamic scene. Its validity and efficiency are verified by demonstration in dynamic environment, where a video projector projects various images in the background.

콘크리트 중력식 댐의 지진응답해석

권혁기 ( Kwon¸ Hyek Kee ),이종근 ( Lee¸ Jong Keun ),안상로 ( Ahn¸ Sang Ro ),신은우 ( Shin¸ Eun Woo ) 한국구조물진단유지관리공학회 2002 한국구조물진단유지관리공학회 학술발표대회 논문집 Vol.6 No.2

The purpose of this study is to suggest some references of maintenance and design of Gravity Concrete Dams by analyzing dynamic characteristics in x, y, z directions when earthquakes occur. We consider gravity concrete dams such as Chunchon, Paldang and Chungju dam in Han River basin as some cases.

지진에 의한 콘크리트 중력식댐의 거동특성 분석

권혁기(Kwon Hyek Kee),이종근(Lee Jong Keun),안상로(Ahn Sang Ro),신은우(Shin Eun Woo) 대한토목학회 2002 대한토목학회 학술대회 Vol.2002 No.11

이기거풍산(理氣祛風散)이 백서(白鼠)의 신경병리성(神經病理性) 동통(疼痛) 억제(抑制) 및 c-Fos 단백(蛋白) 발현(發顯)에 미치는 영향(影響)

이혁재,김종한,박수연,최정화,Lee, Hyek-Je,Kim, Jong-Han,Park, Su-Yeon,Choi, Jung-Hwa 대한한방안이비인후피부과학회 2005 한방안이비인후피부과학회지 Vol.18 No.1

Objective : We have studied to know effects of Ligigeopoongsan(LGS, 理氣祛風散) on mechanical allodynia, cold allodynia and c-Fos protein expression in the model of neuropathic pain of rats. Methods : The model of neuropathic pain was made by injured tibial nerve and sural never while common peroneal never was maintained. After 2weeks, we performed behavioral test for 7 days to try out mechanical allodynia using von frey filament and cold allodynia using acetone, which are calculated by counting withdrawal response on foot. Rat brains removed and sliced on 8th days. Serial sections were immunohistochemically reacted with polyclonal c-Fos antibody. The numbers of c-Fos protein immunoreactive neurons in the central gray were examined using scion image program. Results : 1. Mechanical allodynia in LGS-2, LGS-3 groups were significantly diminished compared with the control group. 2. Cold allodynia in LGS-3 group was significantly diminished compared with the control group. 3. c-Fos protein expression on the central gray LGS-2, LGS-3 groups were significantly lower than that of control group. conclusions : We have noticed that LGS(理氣祛風散) diminished mechanical and cold allodynia in the model of neuropathic pain compared with the control group. c-Fos protein expression in the central gray of that group was also decreased compared with the control group. Pain control group were LGS was accumulated time goes by. This study can be used as a basic resource on a study and a treatment of pain.

급성 호흡곤란 증후군으로 발현된 기관지 결핵 1예

노영준,김종혁,문성용,김지연,김진건,이정훈,고영민 대한내과학회 2004 대한내과학회지 Vol.66 No.4

급성 호흡곤란 증후군은 아직도 사망률이 높지만 조기에 원인을 발견하여 교정 및 치료를 하여 진행을 막고 적적한 유지 요법을 같이 하면 그 예후를 좋게 할 수 있을 것이다. 급성 호흡곤란 증후군의 원인으로 국내에서는 속립성 결핵에 대한 보고는 있었으나 기관지 결핵은 국외에 몇몇의 보고만 있을 뿐 일반적으로 잘 알려져 있지 않다. 기관지 결핵은 기관과 기관지에 결핵의미생물학적, 조직학적 증거를 동반한 감염을 결핵전체의 10-20%를 차지하고, 폐결핵과 동반해서 드물지 않게 나타나기도 한다. 다양한 흉부 방사선 소견과 비특이적 호흡기 증상으로 진단이 지연되어 기관지 협착등의 합병증을 초래하고 이로 인한 호흡곤란과 무기폐나 이차적 폐렴 등을 초래할 수 있다고 보고 되어 왔다. 본 저자들은 급성 호흡곤란 증후군으로 발현된 기관지 결핵에서 즉각적인 항결핵제와 스테로이드의 사용으로 호전되는 증례를 경험하였기에 문헌고찰과 함께 보고한다. Endobronchial tuberculosis is defined as a specific inflammation of the trachea or major bronchi caused by the tubercle bacillus. It is recognized as one of the most common and serious complication of pulmonary tuberculosis. A diagnosis of endobronchial tuberculosis is difficult due to the diversity of radiological patterns. But, it is still relatively common disease in korea. Endobronchial tuberculosis as a cause of the acute respiratory disease syndrome (ARDS) is quite rare. The mortality rate of ARDS is still high in korea. The detection and early elimination of the causes for ARDS at the initial stage can result in a more favorable prognosis. So, patients with ARDS, especially due to endobronchial tuberculosis or other from of tuberculosis, should be treated with antituberculous drugs as soon as possible. We experienced a young female with complaints of sudden onset dyspnea, mild fever. In this case the clinical features, laboratory data and radiologic findings allowed an initial presentation of ARDS. The ARDS was defined by the American-Europian Consensus Conference 1992^(1-30). The cause of ARDS was revealed endobronchial tuberculosis. We started antituberculosis medication and steroid injection quickly, which resulted in good prognosis. We emphasize the prognosis depends mainly on the early recognition and treatment of endobronchial tuberculosis.

최근 30년간 국내 논문에 보고된 납중독증에 대한 고찰

김지연,김종혁,김현우,노지호,이관행,천병철,남상민 대한내과학회 2004 대한내과학회지 Vol.66 No.6

배경 : 납은 우리 주변 환경에 널리 존재하며 오랜 시간 동안 여러 용도로 사용되면서 많은 납중독 사례가 보고 되었다. 특히 우리나라를 비롯한 주변동남아 국가에서는 한약에 의한 비직업성 납중독이 보고 되고 있다. 방법 : 1973년부터 2002년까지 Medric을 통하여 검색한 납중독 관련 논문들과 이들의 참고문헌을 바탕으로 총 45예에 대한 자료를 수집하였고, 이들에 대하여 다음과 같은 특성으로 분류하였다. 1) 보고연도, 2) 연령, 3) 성별, 4) 노출경로, 5) 노출기간, 6) 발현된 중독 증상, 7) 치료 결과 : 전체 환자들의 평균 연령은 41.4세였고, 성별에 따른 분포는 큰 차이가 없었다. 비직업적 납중독은 대부분 한약에 의한 경우들이었다. 한약에 의한 납중독의 경우 한양의 평균 복용기간은 7.3±3.8개월이었고, 복용량은 5 ㎎∼3 g까지 다양하였다. 납중독 환자들의 임상증상은 주로 복통, 두통, 변비 등이었다. 특징적인 실험실 소견으로 빈혈이 관찰되었다. 주 치료 약제는 경구 penicil lamine이 사용되었다. 결론 : 납중독은 임상에서 비슷한 증상을 보이는 유사한 질환이 많아 진단하기에 어려운 면이 있다. 특히 비직업성 납중독의 경우는 더욱 그러하다. 우리나라에서는 서양과는 달리 한약제에 의한 비직업성 납중독이 다수 발견되어 왔다. 본 저자들은 이러한 납중독의 예방과 관리를 위해 건강보조식품이나 한약(특히, 한약류) 등의 과학적이고 합리적인 제조 및 향후 관리가 필요하다고 생각하게 되었다. Background : Because of widespread and long-term use of lead, many lead poisoning cases were reported. Especially, in Korea including Southeast Asia, we observed non-occupational lead poisoning cases by herbal medication. Methods : We identified total 45 cases of lead poisoning through Medric search, from 1973 to 2002. Bibliographies of relevant articles were reviewed. We arranged cases by attributes following 1) reported year, 2) age, 3) sex, 4) exposure sources, 5) exposure duration, 6) clinical manifestation, 7) treatments. Results : The average age of the patients was 41.4±15.7 year-old. The distribution by sex did not have difference each other. The non-occupational lead poisoning cases were mostly caused by Chinese herbal medication. On the cases of the herbal lead poisoning, average exposure duration was 7.3±3.8 months and the various dosages were taken from 5 ㎎ to 3 g. The major clinical symptoms were abdominal pain, headache, and constipation. The typical laboratory finding was anemia. Major treatment agent was oral penicillamine. conclusion : To differential diagnose of the lead poisoning from many diseases with similar symptoms is very difficult solely on the clinical aspect. Especially, in non-occupational cases it is more difficult. In Korea, non-occupational lead poisoning cases by herbal medication have been discovered more than in western countries. We reviewed about the lead poisoning cases since 1973, so we want to make an aware of scientific and rational making and management of lead in the health supplementary food and herbal medicine.

Feeding Habits of the Ocellate spot skate(Raja kenojei) in the Coastal water of the five West Sea islands in Korea

Byeong-ll Youn,Dong-Hyek Choi,Seung-Jong Lee,Seung-Hwan Lee,Kyeong-Ho Han,Maeng Jin Kim 한국수산과학회 양식분과 2020 한국수산과학회 양식분과 학술대회 Vol.2020 No.7

Cloning, Expression, and Characterization of a Hyperalkaline Phosphatase from the Thermophilic Bacterium Thermus sp. T351

( Jeong Jin Choi ),( Jong Woo Park ),( Hyek Yung Shim ),( Suk Chan Lee ),( Moo Sik Kwon ),( Joo Sung Yang ),( Heon Hwang ),( Suk Tae Kwon ) 한국미생물생명공학회 2006 Journal of microbiology and biotechnology Vol.16 No.2