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.

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.

Floristic characteristics of vascular plants and first distributional report of Pseudostellaria baekdusanensis M. Kim in Yongneup wetland protected area

Young-Chul Kim,Hyun-Hee Chae,Sang-Heock Oh,Seung-Ho Choi2,Moon-Pyo Hong3,Gi-Heum Nam,Jae-Yoon Choi,Hyun-Sook Choi,Kyu-Song Lee 한국환경생태학회 2015 한국환경생태학회지 Vol.29 No.2

Yongneup wetland protected area, the only high moor in Korea, is a core area to conserve biodiversity. Even though the Yongneup wetland protected area is relatively small, various plant species are distributed in the Yongneup wetland protected area because it includes various habitats showing different environmental gradients. Vascular plants distributed in the Yongneup wetland protected area were identified as a total of 376 taxa that is composed of 73 families, 217 genera, 322 species, 3 subspecies, 44 varieties and 7 forms. For endangered plants designated by the Ministry of Environment, 5 species including Trientalis europaea var. arctica, Lilium dauricum, Halenia corniculata, Lychnis wilfordii and Menyanthes trifoliata were found and 34 taxa were confirmed to be distributed only in the mountainous wetland habitats. Regarding naturalized plants, a total of 11 taxa were distributed, but most of them were distributed in the areas where artificial interference has occurred. And in areas inside the wetlands that are relatively well preserved, 2 species of Bidens frondosa and Erigeron annuus were observed. In this study, the occurrence and distribution of Pseudostellaria baekdusanensis M. Kim, which was recently found in Mt. Baekdu and reported as a new species, were identified in the Yongneup wetland protected area. A wetland is a very vulnerable area to drastic environmental changes and damages to its ecosystem could cause the extinction of rare plant species which are distributed only in the wetlands. Therefore, it is mandatory that current status of the Yongneup wetland protected area is evaluated and actions to prevent rapid environmental changes are taken. Fourteen separate investigations were conducted in 2013 and another four in 2014, to evaluate current status of the Yongneup wetland protected area. These investigations have provided us the basic information for future actions of conservation and restoration.

Peutz-Jeghers 증후군 1예

최규식,황영남,김영자,양윤모,최영호 대한가정의학회 1985 Korean Journal of Family Medicine Vol.6 No.12

포도당과 이소프로테레놀에 의한 시상하부의 소마토스타틴 분비가 갑상선자극호르몬방출호르몬에 의한 갑상선자극호르몬에 미치는 효과

박철영,양인명,오승준,김덕윤,우정택,김성운,김진우,김영설,최영길 대한내분비학회 2000 Endocrinology and metabolism Vol.15 No.4·5

인터넷 중독 고위험 청소년의 성별에 따른 임상적, 정신병리적 특성

이지윤(Ji Yoon Lee),권준근(Jun-Gun Kwon),이준영(Jun-Young Lee),정희연(Hee Yeon Jung),손보경(Bo Kyung Sohn),최삼욱(Sam Wook Choi),김대진(Dai Jin Kim),최정석(Jung-Seok Choi) 한국중독정신의학회 2016 중독정신의학 Vol.20 No.1

Objectives : Most previous studies of Internet addiction (IA) have been performed on males, and little is known about gen-der differences in IA. We examined gender differences in the clinical and psychopathological features related to high-risk for IA among adolescents. Methods : 714 (male : N=389 ; fe-male : N=325) have reported questionnaires as follows ; 1) clinical and psychopathological features (depression, anxiety, Attention Deficit Hyperactivity Disorder (ADHD) symptoms, Smartphone addiction, impulsivity, behavioral inhibition and approach systems, state-trait anger, aggression, beliefs about aggression, and resilience) 2) Internet and Smartphone usage patterns. In 691 who completed the Young’s Internet Addiction Test (YIAT), A total of 487 adolescents were classified into the normal Internet use group, with YIAT scores of 20-39 (male :N=232 ; female : N=255) and 204 adolescents were classified into high-risk for IA group (male : N=144 ; female : N=60). Results : Most factors described above predicted high-risk for IA in male and female adolescents. Especially, the present study found that psychological resilience had negative association with possibility of IA in female, while cognitive impulsivity and hostile aggression were associated with possibility of IA in male adolescents. Conclusion : This study found gender-re-lated features in adolescents at high-risk for IA. Thus, gender-specific strategies are needed to maximize prevention and treatment effectiveness of IA.

複合 韓藥劑 淸籬滋坎湯의 抗癌效果 및 作用機轉 糾明

Cho, Kyung-Sam,Kim, Si-Young,Park, Jai-Kyung,Choi, Seung-Hoon,Chung, Se-Young,Yoon, Hwi-Joong 경희대학교 동서의학연구소 1999 INTERNATIONAL SYMPOSIUM ON EAST-WEST MEDICINE Vol.1999 No.1

Kyung Sam Cho¹Si Young Kim¹, Jai Kyung Park²,Seung Hoon Choi³,Se Young Chung⁴, Hwi Joong Yoon¹¹College of Medicine, ²East-West Medical Research Institute, ³College of Oriental Medicine, ⁴College of Pharmacology, Kyung Hee University,Seoul, Korea. The Anti-cancer Effect of Oriental Medicine Chung-Ri-Ja-Gam-Tang in the Mouse with Metastatic Lung Cancer. Proceedings of International Symposium on East-West Medicine, Seoul. 231-243, 1999.-The oriental medicine Chung-Ri-Ja-Gam-Tang is an herbal medicine which has been used for pulmonary diseases and known as having immune stimulatory effects. It has been known effective in lung cancer. So we studied the effects and the mechanisms of this herbal medicine it the mouse with metastatic lung cancer. The metastatic lung cancer of the mouse was produced with melnoma cell line(B16BL/6).5×10□/mouse tumor cells were injected intravenously to the CDF1 mouse via tail vein. The mice were divided 4 groups. The first group was treated with 50mg/kg extract of Chung-Ri-Ja-Gam-Tang per oral for 10 days after cancer cell injection, second group treated with saline after cancer cell injection, the third group with medicine without cancer cell, and the last group with saline only. After 10 days treatments some of the mice were scarificed and the lung and spleen was removed. The survival duration, weight change, the number of metastatic cancer nodule of the lung, the NK cell activity, the capacity of cytokines(INF-γ,INF-α,IL-2) production and the proliferation activities of mouse lymphocytes were measured. The surival times of the group 1 mice were longer and the weight loss was less than the group 2 significantly. The number of the metastatic nodule of the lung were decresed in the group 1 than the group 2. The production of INF-γ,was increase in group 2 than group 3 and 4, IL-2 production was increased in group 1 than group 2,3,4 significantly. There was no difference in TNF- α production and proliferation activity of lymphocyte in each group. The NK cell activity was significantly increased in group 1 than group 2,3,4. We conclude that the Chung-Ri-Ja-Gam-Tang has the effect of increasing the NK cell activity of the CDF1 mouse with metastatic lung cancer(B16BL/6). And it is suggested that the increased production of the IL-2 is the mechanisms of enhanced NK cell activity.

Helicobacter pylori와 대장균의 Shuttle Vector 개발

조명제,이우곤,이상룡,김경희,안영숙,김성희,김현주,류복덕,최여정,윤영혜,백승철,전영석,이광호 경상대학교 유전공학연구소 1997 遺傳工學硏究所報 Vol.16 No.-

In this study, a vehicle vector using cryptic plasmids was constructed for gene transfer in Helicobacter pylori. pHP51(3.9 kb) and pHP489(1.2 kb) were selected for constructing vectors from cryptic plasmid of H. pylori isolates in Korea. The HindⅢ-digestedDNA fragment(1.2kb) of pHP489 and 1.6kb DNA fragment of pHP51 were ligated with a kanamycin resistance gene(aph3'-Ⅲ) from C. jejuni to produce the recombinant plasmids pHP489K and pHP51K, respectively. Transformation frequency of pHP51K by electroporation was low. But pHP489K could be effectively transformed into various H. pylori strains. In order to design an intermdiate vehicle vector for gene transfer into H. pylori, pBlueHP489K was prepared by recloning pHP489K DNA into pBluescript and pTZ19R vector. This vector permitted the DNA fragment containing pHP489 sequence, aph3'-Ⅲ, and cloned DNA to be cut and self-ligated in the SacⅠ site after cloning. ureA and ureB gene were inserted into pBlueHP489K, resulting in pBlueHP489K/AB. The DNA fragment containing pHP489, kanamycin resistance gene(aph3'-Ⅲ), and urease structural gene was cut away from pBlueHP489K/AB and self-ligated to generate pBlueHP489K/AB. pBlueHP489K/AB made urease-negative H. pylori strains restore their urease activity. By this experiment, pBlueHP489K was confirmed to be the vehicle system for transferring H. pylori genes.

전경대원에서 발생한 결핵의 임상 양상

문창기,박상준,조민구,김영중,김소연,김윤권,정준오,안석진,김은실,서승오,김지훈,최원제,이윤영,박형기,최규영,김현근 대한감염학회 2006 감염과 화학요법 Vol.38 No.6

Background: The purpose of this study was to document the incidence and clinical characteristics of patients with tuberculosis (TB) in combat and auxiliary police, living in a group, in Korea where the incidence rate of active TB in a general population is higher than in Western countries. Materials and Methods:We retrospectively reviewed the medical records of all tuberculosis patients diagnosed at National Police Hospital from January 2002 through December 2004. Results:In 2002-2004, a total of 156 cases of tuberculosis were identified with the mean (Standard deviation) age of 20.6 (±1.0) years. Of these, 134 (85.9%) patients were registered as new cases, 11 (7.1%) as relapse, 2 (1.3%) as failure, 5 (3.1%) as treatment-after-default cases whereas 4 (2.6 %) patients were not included in any categories. Average annual new TB rate and smear-positive TB rate were 86.5/10^(5) and 17.4/10^(5) person-years, respectively. In 12 of 31 smear-positive cases, time from onset of symptoms to diagnosis was more than 30 days. Two multidrug-resistance TB cases were identified and two suspected outbreak episodes of TB had occurred during 3 years. Conclusion:There was no statistically significant difference in the incidence rate of new cases of TB between the general population aged 20 to 29 years and combat and auxiliary police in Korea. 배경 : 국내 결핵의 발생은 감소 추세에 있으나 여전히 후진국형 발생양상을 보이고 있다. 특히 집단생활을 하는 젊은이들에서 발생하는 결핵의 유행이 간헐적으로 알려지고 있어 우려를 낳고 있다. 이에 저자들은 최근 전경대원의 결핵 발병 양상에 대해 알아보고자 본 연구를 시행하였다. 재료 및 방법 : 2002년 1월부터 2004년 12월까지 3년간 경찰병원에서 결핵 진료를 받은 전경대원의 의무기록을 후향적으로 분석하여 연도별 결핵 신환발생률, 도말양성결핵 신환율, 진단 지연, 집단발병, 다제내성결핵을 조사하였다. 결과 : 연도별 결핵 신환자 수(10만명당 발생추정치)는 2002년 50명(83.6명), 2003년 42명(83.7명), 2004년 42명(93.5명)이었고 도말양성 폐결핵 신환자 수는 2002년 10명(16.7명), 2003년 11명(21.9명), 2004년 6명(13.4명)이었다. 3년간 도말양성 폐결핵 환자는 31명이 있었고 그 중 12명은 호흡기 증상 발생 30일이 지나서 진단을 받았다. 다제내성 결핵은 2명이 있었으며 결핵의 집단발병이 의심되는 사례는 2차례 있었다. 결론 : 전경대원과 20-29세 연령군 일반인의 결핵 신환발생률, 도말양성 폐결핵 발생률의 통계적으로 유의한 차이는 없었다.