AN IN-SITU YOUNG’S MODULUS MEASUREMENT TECHNIQUE FOR NUCLEAR POWER PLANTS USING TIME-FREQUENCY ANALYSIS

YOUNG-CHUL CHOI,DOO-BYUNG YOON,JIN-HO PARK,권휴상 한국원자력학회 2009 Nuclear Engineering and Technology Vol.41 No.3

Elastic wave is one of the most useful tools for non-destructive tests in nuclear power plants. Since the elastic properties are indispensable for analyzing the behaviors of elastic waves, they should be predetermined within an acceptable accuracy. Nuclear power plants are exposed to harsh environmental conditions and hence the structures are degraded. It means that the Young’s modulus becomes unreliable and in-situ measurement of Young’s modulus is required from an engineering point of view. Young’s modulus is estimated from the group velocity of propagating waves. Because the flexural wave of a plate is inherently dispersive, the group velocity is not clearly evaluated in temporal signal analysis. In order to overcome such ambiguity in estimation of group velocity, Wigner-Ville distribution as the time-frequency analysis technique was proposed and utilized. To verify the proposed method, experiments for steel and acryl plates were performed with accelerometers. The results show good estimation of the Young’s modulus of two plates.

AN IN-SITU YOUNG'S MODULUS MEASUREMENT TECHNIQUE FOR NUCLEAR POWER PLANTS USING TIME-FREQUENCY ANALYSIS

Choi, Young-Chul,Yoon, Doo-Byung,Park, Jin-Ho,Kwon, Hyun-Sang Korean Nuclear Society 2009 Nuclear Engineering and Technology Vol.41 No.3

Elastic wave is one of the most useful tools for non-destructive tests in nuclear power plants. Since the elastic properties are indispensable for analyzing the behaviors of elastic waves, they should be predetermined within an acceptable accuracy. Nuclear power plants are exposed to harsh environmental conditions and hence the structures are degraded. It means that the Young's modulus becomes unreliable and in-situ measurement of Young's modulus is required from an engineering point of view. Young's modulus is estimated from the group velocity of propagating waves. Because the flexural wave of a plate is inherently dispersive, the group velocity is not clearly evaluated in temporal signal analysis. In order to overcome such ambiguity in estimation of group velocity, Wigner-Ville distribution as the time-frequency analysis technique was proposed and utilized. To verify the proposed method, experiments for steel and acryl plates were performed with accelerometers. The results show good estimation of the Young's modulus of two plates.

관동맥질환에서 저밀도 지단백 입자 크기의 분포

임효영,김인숙,승기배,강동헌,전두수,장기육,박준철,이수영,홍순조,최규보 대한순환기학회 1998 Korean Circulation Journal Vol.28 No.8

QR코드를 이용한 청소년 체험학습 쿠폰 시스템 개발

박순호 ( Soon Ho Park ),김유두 ( Yu Doo Kim ),문일영 ( Il Young Moon ) 한국실천공학교육학회 2013 실천공학교육논문지 Vol.5 No.1

PC의 빠른 보급으로 많은 사용자가 PC로 다양한 콘텐츠를 즐기고 있다. 특히 최근 들어 청소년들의 PC이용 률이 급격히 증가했다. 청소년들은 이러한 PC를 이용하여 보다 쉽게 정보를 얻을 수 있고, 특히 온라인 게임을 통하여 스트레스를 해소하고, 가상현실에서의 또 다른 재미를 느낄 수 있다. 이렇게 일찍부터 빠르게 발전하고 있는 IT문화를 접하는 것은 좋은 일인 것은 분명하다. 하지만 그로 인해 청소년들은 자연스럽게 실내 활동이 많아지게 되면서 야외활동이 줄어들게 됨에 따라 세상을 보는 시야 또한 많이 좁아지게 되었다. 따라서 청소년 들의 야외활동을 유도하기 위해 최근 많이 사용하는 스마트 폰 어플리케이션을 이용하여 현장체험 쿠폰 시스템을 구축하게 되었다. 그리고 HTML5를 기반으로 하는 하이브리드 앱을 개발함으로써 디바이스의 구분없이 사용할 수 있도록 하였다. 따라서 이 어플리케이션을 통해서 청소년들의 현장체험에 대한 관심과 동기를 유발시킴으로써 많은 볼거리를 체험하고, 다양한 시각에서 세상을 바라볼 수 있다. Because of rapid spread of the PC, many users have been enjoying a variety of content as PC. Especially in recent years, young people has increased dramatically PC usage. Young people get more easily information using a PC. Especially they relieve their stress through online games and feel another fun of virtual reality. It is obviously a good effect that they contact IT culture with rapidly developed. But young people`s perspective with world is narrow because of doing more indoor activities than outdoor. Therefore we built Spot experience voucher system using smart phone application. We hope that many young people act outdoor activities. And Our product offer hybrid device by developing HTML5-based app. Thus this app will give interest of spot-experience to young-people. So If young people use this app, they can have many experience and see diverse aspects.

수입각증후군에 의한 급성 복증 1례

정은욱,지삼룡,이영태,박지훈,김동기,제인수,채두근,박성재,박은택,이연재,이상혁,설상영,정정명 白中央醫療院 2005 仁濟醫學 Vol.26 No.1

Afferent loop syndrome is an uncommon complication of a gastrectomy and Billroth Ⅱ reconstruction. It may cause symtoms at any time from the first postoperative day to many years after the gastrectomy. Afferent loop syndrome is characterized by abdominal pain, vomiting and elevation of serum amylase. Thus, it is difficult to differentiate afferent loop syndrome from other cause of acute pancreatitis. However, the history of gastrectomy can be an important clue for diagnosing afferent loop syndrome. We experienced one case of chronic afferent loop syndrome with acute pancreatitis. After appropriate management, the abdominal pain disappeared and serum amylase level decreased. We report this case with a review of relevant literatures.

가속도계를 이용한 재료의 영계수 측정방법

손창호(Sohn, Chang-Ho),박진호(Park, Jin-Ho),윤두병(Yoon, Doo-Byung),정의필(Chong, Ui-Pil),최영철(Choi, Young-Chul) 한국소음진동공학회 2006 한국소음진동공학회 논문집 Vol.16 No.11

For the description of the elastic properties of linear objects a convenient parameter is the ratio of the stress to the strain, a parameter called the Young's modulus of the material. Young's modulus can be used to predict the elongation or compression of an object as long as the stress is less than the yield strength of the material. Conventional method for estimating Young's modulus measured the ratio of stress to corresponding strain below the proportional limit of a material using a tensile testing machine. But the method needs precision specimens and expensive equipment. In this paper, we proposed method for estimating Young's modulus using accelerometer. The basic idea comes from that the wave velocity is different as the Young's modulus. To obtain Young's modulus, a group velocity is obtained. It is difficult to measure group velocity. This is because plate medium has a dispersive characteristics which has different wave speed as frequency. In this paper, we used Wigner-Ville distribution to measure group velocity. To verify the proposed method, steel and acryl plate experiments have been performed. Experimental results show that the proposed method is powerful for estimating Young's modulus.

수출입 컨테이너 장치장 배정을 위한 소프트웨어의 개발

김갑환,김홍배,홍봉희,김기영,배종욱,최진오,김두열,이영기,박영만,박강태,손행대 한국경영과학회 1995 經營 科學 Vol.12 No.3

The Pusan Container Terminal faces a rapid increase in berthing time of container ships as well as in waiting time of external trucks, which is due to an absolute lack of yard space. This research is focused on the development of a decision support system for the planning of the container terminal yard assignment so that the yard space would be utilized most effectively. Efforts should be given to the reasonable assignment of the yard storage and the dynamic adaptation to the ever changing environment. The software introduced here is based o the know-how of the field exports and its framework takes the approach of the hierarchical decision making.

백서 간재생중 H2B Histone 유전자 발현에 대한 Octamer Binding Transcription Factor의 역할

임규,방재웅,최두식,손미영,이영철,박청,김태동,김영래,박종일,윤완희,박승길,황병두 한국노화학회 2001 한국노화학회지 Vol.11 No.1

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

그레이브스병에서 치료에 따른 폐동맥압의 변화

남택만,조한수,이진서,송영림,김두만,두영철,박철영,정인경,홍은경,이성진,오기원,김현규,유재명,최문기,유형준,박성우 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.5

연구배경: 갑상선기능항진증에 의한 갑상선중독증 환자들은 호흡곤란을 호소하며, 그 원인으로 호흡근의 근력 약화, 좌심실부전으로 인한 폐모세혈관의 울혈, 기도저항의 증가, 갑상선종으로 인한 기관의 압박, 호흡기능 이상 등이 거론되고 있다. 폐동맥고혈압이 동반된 그레이브스병 환자가 여러 증례가 보고되었으며, 폐동맥고혈압 환자에게서 갑상선 자가항체와 갑상선기능저하증의 빈도가 높음이 알려지면서 갑상선중독증이 동반된 그레이브스병 환자에게서 관찰되는 호흡곤란의 한 원인으로 폐동맥압 증가가 작용할 가능성이 제시되고 있다. 이에 저자 등은 그레이브스병 환자를 대상으로 폐동맥압을 측정하고 치료 전후의 폐동맥압의 변화를 전향적으로 연구하였다. 방법: 갑상선중독증이 동반된 그레이브스병 환자와 정상 갑상선기능을 나타낸 대조군을 대상으로 갑상선기능검사 및 갑상선 자가항체를 측정하고, 심초음파를 이용하여 치료 전후로 폐동맥압을 측정하여 폐동맥압과 갑상선기능 및 갑상선 자가항체와의 관계, 폐동맥압의 변화 등을 관찰하였다. 결과: 1. 연구대상은 대조군 10명 (남녀비 1:9, 관해 상태의 그레이브스병 3명, 갑상선종 3명, 정상인 4명), 그레이브스병 환자 26명 (남녀비 7:19)이었다. 2. 대조군과 치료 전 그레이브스병 환자의 폐동맥압은 각각 23.5±2.32 mmHg, 29.6±10.3 mmHg이었고, 치료 전의 폐동맥압과 혈청 갑상선자극호르몬 결합억제 면역글로불린 (TBII) 농도는 유의한 양의 상관관계를 보였다. 3. 26명의 그레이브스병 환자 중에서 10명 (38.5%)이 폐동맥고혈압 (기준: 폐동맥압 > 30 mmHg)으로 진단되었다. 4. 치료 전후로 폐동맥압을 측정한 13명은 폐동맥압이 치료 전 29.6±10.3 mmHg에서 치료 후 폐동맥압 22.2±6.48 mmHg로 의미있게 감소하였다. 결론: 갑상선중독증을 보이는 그레이브스병 환자의 약 40% 정도에서 폐동맥고혈압이 발견되어 폐동맥고 혈압은 그레이브스병에 흔하게 동반하는 질환으로 생각된다. 향후 그레이브스병 환자에서 관찰되는 폐동맥압의 증가와 관련한 병인, 발생기전 및 임상적 의의 등에 대한 연구가 필요할 것으로 생각된다. Background: Exertional symptoms, dyspnea and impaired effort tolerance are common in patients with Graves' disease. Proposed explanations include: high-output left heart failure, ineffective oxygen utilization and respiratory muscle weakness. In addition, pulmonary hypertension has also been reported in patients with Graves' disease. A high prevalence of hypothyroidism and positive thyroid autoantibody were also observed in patients with pulmonary arterial hypertension. Therefore, the pulmonary artery pressure in patients with Graves' disease was evaluated. Methods: Two-dimensional and Doppler echocardiographic examinations (Hewlett Packard Sonos 2500) were performed to determine the pulmonary artery (PA) pressure in 26 Graves' disease patients, both before and after treatment (23 patients with propylthiouracil and 3 with RAI), and in 10 euthyroid controls. The changes in the PA pressure after treatment were evaluated in 13 patients with Graves' disease, who became euthyroid after treatment. Results: The pulmonary artery pressure was increased in the untreated Graves' disease patients compared to the normal controls (23.5±2.32 vs. 29.6±10.3 mmHg). 38.5% of the Graves' disease patients (10/26) showed pulmonary arterial hypertension (PA>30 mmHg) and the serum TBII level was higher in the Graves' disease patients with pulmonary arterial hypertension than in those with normal PA pressure (P<0.05). In the Graves' patients who became euthyroid after treatment, the PA pressure was significantly decreased. Conclusion: 38.5% of the untreated Graves' disease patients showed pulmonary arterial hypertension, and the pulmonary artery pressure was significantly decreased in those who became euthyroid after treatment. The pathogenesis and clinical importance of pulmonary arterial hypertension in Graves' disease requires further studies (J Kor Soc Endocrinol 18:465∼472, 2003).