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.

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.

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.

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.

감압밸브를 포함한 송수관로의 수격압 방지설계

윤재흥,최두용 대한상하수도학회 2003 상하수도학회지 Vol.17 No.3

This study proposes procedures of water transient analysis and methods of designing pressure relief valves and surge pipes in the complex water transmission system which includes many branches, reservoirs and pressure reducing valves. Since those kinds of analysis and procedures have not been studied until now, the proposed methods and procedures will be a basis for making the transient analysis of similar systems efficient. The cases that are considered in the analysis are sudden closure of pressure reducing valves and slow closure of reservoir flow control valves. In the latter case, the pressure reducing valves can keep fully open or can react on the downstream pressures of the valves.

職場人의 體育活動 參興實態 調査硏究

尹영복,元泳枓 조선대학교 사범대학 부설 교과교육연구소 1998 敎科敎育硏究 Vol.1 No.1

This study is intended to research into the realities of participation of the workes employed by companies in physical activities. To do so, used are four questions about the characteristics of the subjects of the study and nine ones about the actual conditions of workers' participation in sports for all. The analyses of materials according to process lead to the following conciusions. 1) About a health condition, 4629% of the respondents(626) think themselves healthy, 40.55% doubtful and 13.16% sick. 2) It is shown that 77.23% of them take rogular or irreularl exercise, and 22.77%9146) of them do not exercise at all. 46.24% of the non-excerisers ascribes their non-exercise to lack of timo, 18.53% of them to absence of co-exercisers and the restof them to no around-them facilities, money or especially interesting sports. 3) It is shown that 74.10% of the exerciseres 480 are engaged in physical activites mainly on behalf of health improvement 67.74% exercise with a frequency of two times a week, 21.30% three times, 13.96% over five times, 27.07% take exercisewith the duration of 40-50 minutes, 24.57% 30-40 minutes, 20.04% 20-30 minutes and 17.21% over 60 minutes. 4) Among those involved in physical activites(480), 49.73% exercise on holidays or weekends, 28.59% on every day, and 21.68% on weekdays. The expenses spent on their exercise are less than ￦50,000 for 60.64%, ￦50,000-70,000 for 26.74%, ￦70,000-100,000 for 10.76% and over ￦100,000 for 1.86%. 5) What they(480) complain about is lack of space and facilities for 33.20%, lack of continuance of exercise programs for 28.04%, formality for 24.63%, and need of a leader of sincerity for 14.13%, their participating in physical activities at work.

호남지역 역도 선수들의 스포츠 상해에 관한 연구

윤오남,위승두,서영환 한국스포츠리서치 2001 한국 스포츠 리서치 Vol.12 No.4

This study aims to present basic data for prevention of injuries and improvement of competitive power in weight lifting. For this, 42 high school lifters and 50 university lifters were inquired about injuries and the results were analysed as follows : 1. The injuries are caused by chronic fatigue(51.86%, highest), weather, intensity of physical activities, and technical characteristics . 2. Most injuries are caused when lifters are sitting(43.1%) in pulling up. In clean and jerk, sitting causes many injuries. In reinforcement, squat causes 43 injuries, the highest. 3. Consider injured part of lifters : 226 injuries o f(85.28 %) shoulder joints, 58 cases (45.31%) of muscular inflammation of elbow part, 205 cases(82.66%)of lumbago on waist part, 232 cases(88.55%)of pain on the knee, 40 cases(33.90%) of muscular cramp on the leg and 85 injuries(57.82%) of the ankle. 4. Consider the frequency of injuries : 10.00 times of sprains of shoulders, 2.00. times of bruise of the elbow, 3.33 times of lumbago of the waist, 3.39 times of pains of the knee and 10.50 times of ankle fractures. 5. As for first aid for injuries, there are 52 cases(55.91%)of putting PAS. Lifters with injuries usually went to hospital for treatment(50 cases and 5.76%). The period of treatment is one through five days(31 cases and 33.3%). Finally, lifters consider sound rest for prevention of injuries after treatment of injuries(61 cases and 65.59%). Lifters and relevant staff should concentrate on establishment of safety countermeasure and should examine types and parts of injuries to reduce injuries. Lifters with injuries should see professional doctors for proper treatment which would prevent aftereffects and bring complete recovery.

도시지역 합류식 하수관거 월류수의 오염부하 특성

윤현식,이두진,이영대 漢陽大學校 環境科學硏究所 2003 環境科學論文集 Vol.24 No.-

합류식 하수관거 월류수(Combined sewer overflow, CSOs)는 도시 인근 방류선 수체의 주요한 오염원의 하나로 알려져 있으며, 특히 강우초기 월류수의 경우 높은 오염부하가 일시에 방류되어 심각한 문제를 야기시킨다. 본 연구에서는 도시지역 합류식 하수관거 월류수의 발생 및 오염부하 특성을 분석하고, 초기강우에 의한 세척효과, 오염원 기여도 평가 등을 수행하였다. 강우사상에 따라 다소 차이가 있었으나, 합류식 하수관거 월류수가 건기하수에 비하여 오염부하가 전반적으로 높았으며, 특히 월류초기에는 매우 고농도로 측정되었다. 근사적인 오염물질 수지식을 통하여 관거퇴적물의 재부유에 의한 오염기여도가 가장 높았다. 무차원 L(V)곡선이 초기세척현상(First flush)을 잘 표현하였으며 SS, CODcr, T-P, T-N의 순으로 초기세척효과가 크게 나타났다. Combined sewer overflows(CSOs) have been considered as a major cause of water quality deterioration of natural water-courses in the vicinity of the heavily urbanized areas. The factors defining the magnitude and occurrence of CSOs are site specific. It is important to know exact properties of pollutants contained in CSOs to address water quality impacts that are caused by CSOs inputs to the receiving waters. This should be accompanied with an integrated analysis, evaluation programs, thus allowing us to an appropriate technology to alleviate the impacts. Pollutant concentrations measured during the storm events were generally higher than those of dry weather conditions except for T-N parameter and observed significant higher concentrations at the initial phase of CSOs. Based on the rough estimation by the proposed pollutant mass balance, it was found that a main part of wet weather pollutional loads originates from the resuspension of sewer bottom sediments. The dimensionless L(V) curves for determining whether first flush phenomenon occur or not were well described the pollutant flushing. These results show that a given fraction of volume contains a load of SS higher than CODcr, T-P, T-N in the initial phase of wet weather runoff.

관상동맥 스텐트 삽입술 후 항합요법의 무작위 비교

윤영섭,이두희,편욱범,김인재,장양수,조승연,심원흠 대한순환기학회 1999 Korean Circulation Journal Vol.29 No.7