Zirconium 합금 관 임계좌굴 압력의 불확실성에 따른 최소안전율

김형규(Hyung-Kyu Kim),김재용(Jae-Yong Kim),윤경호(Kyung-Ho Yoon),이영호(Young-Ho Lee),이강희(Kang-Hee Lee),강흥석(Heung-Seok Kang) 대한기계학회 2010 대한기계학회 춘추학술대회 Vol.2010 No.11

Uncertainty of the elastic buckling formula of a thin tube is considered. The measuring uncertainty of Young’s modulus and Poisson’s ratio and the tolerance of the tube thickness and diameter are dealt with. The elastic buckling should be absolutely prohibited for a thin tube like a nuclear fuel rod that should satisfy a self-stand criterion. Since the predicted critical buckling pressure overestimated the actual one observed from an experiment, determination of the minimum safety factor is crucial. The uncertainty of each parameter (i.e., Young’s modulus, Poisson’s ratio, thickness and diameter) is mutually independent, so the safety factor is evaluated as the sum of the inverse of each uncertainty. It is found that the thickness variation strongly affects the uncertainty. The minimum safety factor of a thin tube of Zirconium alloy needs to be from 1.547 to 3.487 for the thickness of 0.87 and 0.254 ㎜, respectively.

지르코늄 합금 관의 임계좌굴 압력 산정을 위한 최소안전율

김형규(Hyung-Kyu Kim),김재용(Jae-Yong Kim),윤경호(Kyung-Ho Yoon),이영호(Young-Ho Lee),이강희(Kang-Hee Lee),강흥석(Heung-Seok Kang) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.3

얇은 관 탄성좌굴 공식의 불확실성을 고려하기 위해, 공식을 구성하는 파라미터인 튜브재료의 탄성계수, 푸아송 비, 튜브 두께 및 지름의 불확실성을 분석하였다. 본 연구는 원자로에서 연소되는 핵연료봉과 같이 사용 중 함몰을 엄격히 방지하고 있는 얇은 관의 설계신뢰도를 향상시키는 데에 중요하다. 분석 방법은 각각의 파라미터가 변화할 수 있는 범위를 충분히 포함할 수 있는 최소의 탄성좌굴 안전율을 구하고 이를 선형적으로 합하여 최종의 최소안전율을 구하였다. 최소 안전율에 가장 큰 영향을 미치는 파라미터는 관의 두께로 나타났다. 두께가 얇을수록 더 큰 최소안전율이 필요하며 예로 적용한 지르코늄 합금관의 경우, 두께가 0.254 와 0.87 ㎜ 일 때 최소안전율은 각각 1.547 과 3.487 로 나타났다. We consider the uncertainty in the elastic buckling formula for a thin tube. We take into account the measurement uncertainty of Young’s modulus and Poisson’s ratio and the tolerance of the tube thickness and diameter. Elastic buckling must be prohibited for a thin tube such as a nuclear fuel rod that must satisfy a self-stand criterion. Since the predicted critical buckling pressure overestimated that found in the experiment, the determination of the minimum safety factor is crucial. The uncertainty in each parameter (i.e., Young’s modulus, Poisson’s ratio, thickness, and diameter) is mutually independent, so the safety factor is evaluated as the sum of the inverse of each uncertainty. We found that the thickness variation greatly affects the uncertainty. The minimum safety factor of a thin tube of Zirconium alloy is evaluated as 1.547 for a thickness of 0.87 ㎜ and 3.487 for a thickness of 0.254 ㎜.

들깨잎의 揮發性 香氣成分에 關한 硏究

姜興順,林順英,南昌祐,尹錫權,邊時明 同德女子大學校 1995 同大論叢 Vol.25 No.1

To investigate the volatile flavor components of perilla leaves, analyses of kinds of cultivar by GC, GC/MS, UV, IR and NMR were carried out. The results obtained were summarized as follows : 1. The essential oils were extracted with diethyl ether after steam disillation. 2. The identified volatiles include 10 hydrocarbones, 6 alcohols, 3 aldehydes, 2 ketones and 1 miscellaneous components. 3. The major volatile component perilla ketone was identified by UV, IR and NMR spectrum. 4. The perilla ketone were identified in Suwon 8, 19, 21, 23, 24, 25, 26 and purpurea while perillaldehyde was identified in purpurea only.

위성통신 회선상에서 방해전파가 QPSK신호에 미치는 영향

姜榮興 群山大學校 1990 論文集 Vol.17 No.-

The error rate equation of MPSK(M-ary PSK) signal transmitted through the nonlinear satellite transponder has been derived in the Tone or Noise jamming Uplink and Downlink Gaussian noise environment. The error rate performance of BPSK and QPSK system has been evaluated and shown in figures in terms of Uplink and Downlink carrier to noise power ratio, α and α₂, respectively, carrier to Tone jamming power ratio, ??, carrier to Noise jamming power ratio, ??. In the analysis it has been shown that Tone jamming effects on the error rate performance in BPSK and QPSK nonlinear satellite system become less by increasing the Uplink CNR(CNRI) than Tone jamming??, but Noise jamming effects on above system depend on only the Noise jamming?? not the Uplink CNR(CNR1). In conclusion, the QPSK nonlinear satellite system is degraded more severely by the effects of Noise jamming than Tone jamming.

고정 M/W 서비스에 미치는 WLL 시스템의 간섭 영향 분석

강영홍 群山大學校 情報通信技術硏究所 1998 情報通信技術硏究論文集 Vol.2 No.-

This papar analyzes the effects of interference from WLL system has been introduced as a new service into the fixed-service M/W system. To achieve this goal, the interference powers of WLL forward link and reverse link, respectively, effects on a M/W station has been examined and estimated. As the results the interference power from the forward link of WLL system increases proportional only to the base's transmitting power, but the interference power from the reverse link increases proportional to the subscriber's transmitting power and as the cell radius decreases. Although this paper analyzes only the effects of interference from WLL system into M/W system, it can be easily extended to analyze the effects of interference form M/W system into WLL system.

가우스 및 원단누화 잡음환경에서의 디지털 가입자라인의 SNR 성능에 관한 연구

강영흥 群山大學校 情報通信技術硏究所 1999 情報通信技術硏究論文集 Vol.3 No.-

In this paper, we have evaluated BER performance of digital subscriber line(DSL) using the twisted-pair channel model by means of Semi-analytic simulation technique. As a result, it was known that the Semi-analytic simulation was proved to be a good technique because of the attenuation of 0.5dB. To keep the BER=10^-7, 4dB of E_b/N_0 is needed more when DSL length extends to 5000m, while 2dB increase of E_b/N_0 is required when Nyquist frequency goes to 512kb/s with the keeping same distance. In addition, the effect by FEXT noise is serious, when the FEXT noise damping constant, k is over 10^-10 in DSL length and 10^-14 in the aspect of Nyquist frequency. As the basic data, results of this analysis can be used in setting the internal and external standardization of DSL system in the future.

HAPS와 NGSO 시스템의 Feeder Link상의 간섭분석

문승영,김봉석,강영흥 군산대학교 정보통신기술연구소 2000 情報通信技術硏究論文集 Vol.4 No.-

In this paper, interference effects between NGSO and HAPS in the feeder link have been simulated and analyzed by means of calculating excess time percent and duration below the C/I protection ratio. As the results, in the case of HAPS interference into NGSO, it can be obtained that the lowest C/I values are 20.42dB in 50Km and 12.73dB in 20Km of HAPS altitudes, respectively. And in the case of NGSO interference into HAPS, it can be obtained that the lowest C/I values are 13.94dB and 10.42dB respectively. HAPS system has more interference reception from other systems or effects more interference into other systems as its altitude is lower. Also, the lowest C/I values are appealed at difference time with its altitude.

CANDU 사용후핵연료 수송용기 방사선차폐 영향평가

이홍영,정성환,윤정현,강희영,최종락 대한방사선 방어학회 1993 방사선방어학회지 Vol.18 No.2

중수로형 원자로에서 방출되는 사용후핵연료 다발을 안전하게 운반할 목적으로 CANDU 수송용기에 대한 방사선차폐해석을 수행하였다. 핵연료의 연소도는 7,800MWD/MTU, 냉각기간은 5년으로 하여 ORIGEN2 코드로 방사선원을 구하고 이것으로 핵연료 378다발을 운반할 수 있는 수송용기의 차폐체 두께변화에 따른 선량율 영향을 비교하였다. 계산은 ANISN과 DOT4.2 코드를 사용하였으며, 해석결과 최적의 차폐구조를 선정하였으며, 또한 IAEA 및 국내원자력법의 수송법규에 명시된 정상수송 및 가상사고조건에 따른 차폐해석을 수행하여 CANDU 수송용기의 안전성을 입증하였다. A shielding analysis of the shipping cask for transporting the CANDU spent fuel bundles has been studied. Radiation source term has been calculated on spent fuel with burnup of 7,800 MWD/MTU and 5 years cooling time by ORIGEN2 code. The shielding calculation for the cask capable of transporting 378 bundles of CANDU spent fuel has been made by use of 1-D ANISN and 2-D DOT 4.2 codes. As result of analysis, the optimum shield thickness of cask was obtained. And it is proved that the safety in radiation shielding under normal transport and hypothetical accident conditions is confirmed to satisfy the allowable values specified in IAEA Safety Series No. 6 and the Korean Atomic Law.

흡연자와 비흡연자의 타액에서 코티닌 정량 및 ETS 노출량 평가

임흥빈,강영국,손형옥,이영구,문자영,이동욱 충북대학교 엽연초연구소 2001 煙草硏究 Vol.18 No.-

This study was conducted to measure and compare the salivary cotinine concentration between smokers and nonsmokers, and to investigate the effect on the exposure to environmental tobacco smoke(ETS) with housewives, living on an apartment of Korea. Saliva samples were taken from all volunteers and salivary cotinine was analyzed by a developed radioimmunoassay(RIA) method. The median salivary cotinine levels were 52.8±12.6 ng/ml and 44.6± 9.7 ng/ml in male smokers and in female ones, respectively, and they were 4.3±2.1 ng/ml and 2.9±3.1 ng/ml in male nonsmokers and in female ones, respectively. In addition, average salivary cotinine levels were 3.8±2.7 ng/ml in housewives from smoking homes and 2.4±2.4ng/ml in ones from nonsmoking homes. Results obtained from the analysis of salivary cotinine demonstrate that smokers had a significantly higher concentration of salivary cotinine than nonsmoker. But, there was no significant difference in the salivary cotinine concentration for housewives living in apartment between with smoking husband and with nonsmoking husband.

관상동맥질환에서 Tc-99m Methoxyisobutyl Isonitrile (MIBI) Myocardial SPECT의 이용 : Dipyridamole 심근부하 SPECT와 관상동맥조영술과의 비교 A Comparison between Coronary Angiography and Tc-99m-MIBI Myocardial SPECT

이강욱,전은석,박종훈,신영태,노흥규 충남대학교 의과대학 지역사회의학연구소 1993 충남의대잡지 Vol.20 No.2

In order to evaluate clinical utilities of Tc-99m MIBI dipyridamole stress myocardial SPECT in patients with coronary artery disease (CAD), we compaired tomographic and polar map images of Tc-99m MIBI myocardial SPECT with the results of coronary angiography in 25 patients with CAD (myocardial infarction 13,angina pectoris 12) in Chungnam National University Hospital from Oct. 1991 to Oct 1993. Percutaneous transcoronary angioplasty (PTCA) was done in three patients of 25 CAD patients and follow up SPECT studies were done in same three patients within 2 months after PTCA. The results were as follows : 1. Mean age of patients was 57.4 years. Man was 2.7 times more than woman. 2. Sensitivity and specificity of Tc-99m MIBI myocardial SPECT for the detection of coronary artery stenosis in patients with myocardial infarction were 92.7 % anf 85 %, respectively. 3. Sensitivity and specificity of Tc-99m MIBI myocardial SPECT for the detection of coronary artery stenosis in patients with angina pectoris were 100 % and 67 %, respectively. 4. After PTCA size of perfusion defects in stress SPELT images was decreased in all three patients . With the results above,we thought that Tc-99m MIBI myocardial SPECT is useful noninvasive method to detect stenosed coronary artery in patients with CAD and it can be used as a method to evaluate the result of PTCA.