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.

Pseudomonas sp. AC-711이 생산하는 알칼리성 Cellulase의 부분정제 및 효소적 성질

윤민호,임상호,최우영 충남대학교 농업과학연구소 1998 농업과학연구 Vol.25 No.1

The cellulase components were partially purified from the culture filtrate of the alkalophilic bacterium Pseudomonas sp. AC-711 and its enzymatic properties were characterized. The specific activity of the purified major enzyme component was 3.5 units/mg protein as carboxymethyl cellulase and the yield was 23% of the total activity of the culture broth. The molecular weight of the component was 46,000 and the Km and Vmax on CMC were determined as 15.4 mg mL^-1 and 4.17 μmoles mL^-1 min^-1, respectively. The enzyme was stable at the temperatures below 60℃ and at the pH range of 4.0~11.0, and the optimal temperature and pH were 60℃ and pH 8.0, respectively. The enzyme activity was not significantly affected by the common surfactants (concentration: 0.05%) such as α-olefin sulfonate, linear alkylbenzene sulfonate, sodium dodecyl sulfonate, hexadecyltrimethylammonium bromide and Tween 80. The enzyme was activated by the metal ions such as Ca^2+, Cu^2_, Co^2+, whereas inhibited by Hg^2+ and Zn^2+. The enzyme exhibited relatively high activity toward amorphous CMC as compared with crystalline substrates such as filter paper and avicel.

관절 연골 결손의 치유에 대한 실험적 연구

윤영성 全南大醫大 1981 전남의대학술지 Vol.18 No.2

정신분열병 양성 및 음성증상과 혈소판 Monoamine Oxidase 활성도

윤성환,김영훈,진성태 大韓神經精神醫學會 1991 신경정신의학 Vol.30 No.1

The intention of this study to investigate the relationship between the activity of platelet MAO and positive and negative symptoms in the male chronic schizphrenics by DSM-III. The authors devided the male chronic schizophrenics into positive, mixed and negative subgroups by Andreasen & Olsen Criteria(1982), and also each patient was evaluated in relation with positive and negative symptom scales proposed by Lewin & Meltzer(1984). The authors assayed kinetic constants(Vmax and Km) for platelet MAO from 22 drug-free schizophrenics and 22 normal controls, radioenzymatically using 14C-benzylamine as a substrate. The results were as follows ; 1) Schizophrenic subjects had a lower mean Vmax Value(5.20±1.58 nmoles10(-6) platelets/hr) and Km value(38.92±19.28×10(-6)M) for poatelet MAO than normal controls(8.07±4.54, 49.56±18.48). Authough lower mean Vmax had a statistical significance, Km did not have. 2) In case of paranoid group(n = 6), there were no statistical differences in kinetic constants for platelet MAO compared with non-paranoid group(n = 16). 3) There were no significant differences in kinetic constants for platelet MAO between positive, mixed and negative symptom group. 4) The difference between kinetic constants for platelet MAO and positive symptom scale and negative symptom scale were not significant statistically. 5) Each scale item in the negative symptoms was not significantly different from platelet MAO activity. Finally, we confirmed that activity of platelet MAO was lowered in chronic schizophrenics, but we did not find any possible relationship between the negative symptom of schizophrenia and kinetic constants for platelet MAO.

고칼륨혈증에서 심전도의 진단적 의의

윤수영,박원녕,정성필,김승호,이한식 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background: Hyperkalemia is a common and potentially life-threatening metabolic disorder. The electrocardiogram(ECG) is known to be a relatively sensitive diagnostic tool for hyperkalemia. However many exceptions, in which patients showed normal ECG findings even though hyperkalemic, have been reported. The purpose of this study was to determine the extent of correlation between the ECG findings and hyperkalemia and to determine when the ECG has value for diagnosing hyperkalemia. Methods: Patients who had been diagnosed as having hyperkalemia at two university hospitals during three years were enrolled in this study. We reviewed the medical records of the patients and evaluated the following 6 ECG abnormalities: tall T waves, narrow T waves, QRS widening, atrioventricular block, loss of P waves, and sine waves. We defined tall T waves and narrow T waves as 20 percentiles of heights and widths of the T waves from the 100 patients with normokalemia. Results: During the study period, there were 100 hyperkalemic patients, and we analyzed 69 available electrocardiograms. Abnormal ECG findings were revealed in 67%of 69 patients. The higher the serum potassium level, the more abnormal ECG findings. The common ECG abnormalities were tall T waves and loss of P waves. The patients with normal ECGs even though hyperkalemic had relatively low potassium levels. And whether chronic renal disease was not correlated to the ECG abnormality. Conclusion: The electrocardiogram is a good diagnostic tool for hyperkalemia if it is used with accurate diagnostic criteria. Thus, hyperkalemia should be considered when the ECG shows tall T waves or loss of P waves.

ATM망의 VPC/VCC Connection Group 관리를 위한 Circular-Get-Request

윤영우,문성헌 嶺南大學校 工業技術硏究所 1998 工業技術硏究所論文集 Vol.26 No.2

Recently, along with many studies to improve the traditional SNMP, some plans to effectively apply SNMP to the management of ATM networks have been devised. Connection Group MIB is one of these plans. It is proposed as a method to manage the VPC/VCC of the ATM switches, that is to say, as a method to equalize the indexes of the identical managed objects among the switches. But, Considering current technology of multicast services on the ATM network, the benefits gained by application of Connection Group MIB method to the real ATM network, would not so great. In this paper, we analyze some problems of Connection Group MIB method and propose a new circular-get request PDU to solve these problems.

Paraquat 중독환자의 초기검사로서 sodium dithionite를 이용한 소변내 paraquat검출의 임상적 의의

윤갑준,임경수,이진웅,김영식,이부수,박덕우,김선만,이강현,황성오,안무업 대한응급의학회 1995 대한응급의학회지 Vol.6 No.1

Background : Mortality from paraquat intoxication depends upon plasma paraquat concentration. To know the severity of paraquat intoxication is important for directing therapeutic modality and predicting prognosis. Sodium dithionite test for urinary paraquat provides an easy and simple method to determine the severity of paraquat intoxication in emergency department. purpose : To determine whether the result urinary paraquat test by sodium dithionite can predict outcome in patients with paraquat intoxication in emergency department. Subjects : 48 patients(male 31, female 17, mean age 37 years) who had exposure to paraquat and presented within 24 hours after exposure. Result : Thirty five patients were positive in paraquat urine test and thirteen patients were negative. Clinical manifestations were more severe in positive patients than in negatives. Complication was much more in positives than in negatives. 28 of 35 patients(80%) in positives and 2 of 13 patients(15%) in negatives died. Conclusion : Positive test for urinary paraquat is associated with high mortality and morbidity from paraquat intoxication, and qualitative test for urinary paraquat by sodium dithionite is an useful method to determine the severity of paraquat intoxication in emergency department.

관성타원을 이용한 다관절의 로보트의 동특성 해석

윤영식,이상조 연세대학교 산업기술연구소 1987 논문집 Vol.19 No.1

The dynamic characteristics of multi-body such as an articulated arm is analyzed and simulated by using the generalized inertia ellipsoid(GIE). Unlike the inertia ellipsoid of a single body, the GIE of multi-body, changes its shape and orientation depending on the configuration of the arm because of nonlinear effects like Coriolis and centrifugal forces. The reciprocal of the square root of the maximum eigenvalue of generalized inertia tensor of the arm tip is corresponding to the minor axis and to the maximum resultant inertia. The speed of the arm tip is maximum along the direction of the eigenvector of the generalized inertia tensor (and vice versa). The results of this study can be applied to design of the robot structure, i.e. the design parameters of the robot can be determined to have an isotropic inertia characteristics and reduce the nonlinear effects through the working space of the robot.

협력적 필터링 기법을 이용한 P2P 모바일 에이전트 기반 서비스 처리 모델

윤효근,이상용 公州大學校 工學硏究院 生産技術硏究所 2004 論文集 Vol.12 No.-

Context-awareness is an important element that can provide service of good quality according to user's surrounding environment and status in ubiquitous computing environment. Information gathering tools for context-awareness use small size mobile devices which has a mobile agent. Now, a mobile agent is consuming much times and expense to collect and recognize each user's context information. Therefore, needs research about model to reduce mobile agent's load and to recognize user's context information in rapid time. This paper proposes a P2P mobile agent model that mixes filtering technique and a P2P agent in mobile agent. The proposed model analyzes each user's context information in uniformity area and makes groups with similar preference degree. This model continuously observes and learn users' action and service, and measure new interrelation.

소득작물 전후작지 적응 극단기성 벼 ‘중모 1032’

손영보,이종희,조준현,이지윤,오성환,송유천,박동수,박노봉,김상열,여운상,남민희,권영업 忠北大學校 農業科學硏究所 2015 農業科學硏究 Vol.31 No.2