複素 雙人力 記述函數를 이용한 制御系의 應答速度 補償에 관한 硏究

권세현,조용갑,박양수,최부귀 東亞大學校 附設 情報通信硏究所 1995 情報通信硏究所論文誌 Vol.3 No.1

The technique for the synthesis of the dual-input describing function(DIDF) is introduced here and the construction of a non-linear electronic compensator(N-L-E-C) based on this technique is proposed. The above non-linear network is used to compensate linear and non-linear systems for instability,speed of response, limit cycle and the static accuracy.

과학교등학교 학생들이 전분 실험에서 생성한 생물학 가설의 설명 경향 분석

권용주,이준기,정진수 경북대학교 사범대학부속 중등교육연구소 2007 중등교육연구 Vol.55 No.1

Bacillus cereus에 있어서 Phospholipase C활량에 관한 몇가지 계면활성제의 영향

권오용,윤희주,한수자 충남대학교 자연과학연구소 1987 忠南科學硏究誌 Vol.14 No.2

This study demonstrates the effects of four detergents and three on the activity change of phospholipase C which is prepared from the cultural broth of Bacillus cereus. This assay of phospholipase C activity was carried out with phosphatidylcholine micelles which were mixed with the detergents and sterols, with increase a molar ratio of these compounds to phosphatidylcholine. Phospholipase C was highly activated at 0.5 molar ratio of Tween 80-mixed micelles. In the case of Triton X-100, it was activated at higher molar ratio indicated 1.0. Sodium dodecyl sulfate was more effective than that of the other detergents at lower molar ratio. However sodium deoxycholate-mixed micelles increased the activity more 7 times than that of the control group. This maximum activation was occurred at 2.5 molar ratio and the turbidity was gradually decreased. Cholesterol and ergosterol increased the activity until molar ratio reached up to 0.9. But the activity was higher at 0.3 molar ratio for stigmasterol. Consequently, it was indicated that phospholipase C was activated with the supplement of detergents until the mixed micelles made a number of small and spherical shape.

정밀 소형 Ball Screw의 Infeed 전조에 의한 청정 생산기술개발에 관한 연구

권용재,예인수,현동훈 한국공작기계학회 2006 한국공작기계학회 추계학술대회논문집 Vol.2006 No.-

This paper summarizes the results of the parameter conducted to analyze the effect of the rolling pressure, the rotational speed and the feedrate on material flow and thread profile for Ball Screw. Initial bank diameter affect a quality of Ball Screw in small size and the precision rolling process. Therefor, it is very important to determine the optimum bank diameter in the rolling process. And we have to development clean technology of Small Ball Screws by Infeed Rolling Machine.

20km와 150km의 도로싸이클 주행이 혈중 렙틴, 지질과 호르몬 수준에 미치는 영향

최용어,권봉안,오재근,김범수,조준용,김문희 한국체육대학교 체육과학연구소 2000 韓國體育大學校附屬 體育科學硏究所論文集 Vol.19 No.1

Serum leptin, glucose, lipid profiles (free fatty acid, triglyceride, total cholesterol) were determined in two groups of subjects undergoing long and short strenous cycle race, 8 men who fasted overnight and then pedaled 20km cycle race and 8 men, 150km cycle race, respectively, Blood samples were collected before race, immediately after cessation of race and 2hr, 6hr after the end of race period. Cyclist pedaling 20km cycle race and cyclist pedaling 150km cycle race showed no statistical differences in leptin level. After 6hr of rest, leptin concentrations were gradually decreased but showed no statistical different in both groups. Epinephrine (p〈.01) and norepinephrine (p〈.001) concentration in comparison to pre-race levels were increased significantly. But insulin concentration in comparison to pre-race levels were decreased significantly (p〈.001). Glucose (p〈.01), free fatty acid (p〈.001), cholesterol (p〈.001) and triglyceride (p〈.01) were increased immediately after cessation of race in both groups.

정신분열병 환자의 가족부담 척도 개발에 대한 예비연구

김철권,조진석,서지민,김용관,김호찬,김현수,김상수,제영묘 大韓神經精神醫學會 1999 신경정신의학 Vol.38 No.3

연구목적 : 정신분열병 환자의 가족이 느끼는 부담을 측정하기 위한 가족부담 척도를 개발하기 위함이다. 방 법 : 200명의 정신분열병 환자 가족과의 비구조적 면담과 외국 부담척도 고찰을 통하여 94문항을 수집하였고 그 다음에 전문가들과 가족들이 문항 및 영역을 분류하고 통합하여 최종적으로 36문항을 선정하였다. 그리고 정신분열병 환자의 가족 135명, 불안장애 환자의 가족 22명, 기분부전장애 및 신체화 장애 환자의 가족 26명, 치매 환자의 가족 49명을 대상으로 신뢰도와 타당도를 검증하였다. 결 과 : 자료분석 결과 검사-재검사 신뢰도, 내적 일치도, 감별타당도 모두 높게 나타났으며, 요인분석을 통해 다섯 가지 구성요인이 추출되었다. 결 론 : 본 가족부담 척도는 정신분열병을 포함한 만성 정신질환을 앓고 있는 환자의 호전과 가족의 부담을 덜어주기 위한 다양한 프로그램의 효과를 검증하는데 유용하게 사용되어질 수 있을 것이다. Objectives : This preliminary study was carried out to develop the Family Burden Scale(FBS) of the schizophrenics. Methods : Ninety-four items were collected by interviewing in a free unstructured format with one relative of each 200 schizophrenic patients and reviewing foreign FBS's. Several professionals and relatives were asked to group and integrate them into several categories. Finally 36 burden items were chosen to constitute a FBS. The FBS was administered to the relatives of 135 schizophrenic, 22 anxiety disorder, 26 dysthymic disorder and somatization disorder, and 49 dementia patients for examining the reliability and validity. Results : The FBS showed high test-retest reliability, internal consistency, and discriminant validity. The results of the factor analysis revealed five-factor solution. Conclusion : The FBS can be used to evaluate the effectiveness of various programs intended not only to reduce decompensation among schizophrenics, but also to alleviate family burden.

초음파현미경에서 V(z)곡선을 이용한 세라믹/금속 접합면계면의 비파괴 평가

조동수,박익근,김용권 한국비파괴검사학회 2004 학술대회 논문집 Vol.- No.-

급결제 및 혼화제 종류가 숏크리트 내구성에 미치는 영향에 관한 연구

백신원,권소진,이영수,김의성,신용석 한국안전학회 2003 한국안전학회지 Vol.18 No.3

Concrete and shotcrete should withstand the conditions for which they have been designed, without deterioration, over a period of years. But concrete and shotcrete are being deteriorated according to aging by internal and external causes. Recently, many studies on the durability of concrete have been conducted. But the durability of shotcrete is rarely studied. So, in this study, chloride ion penetration test, freeze and thaw test, neutralization test were conducted to examine the durability characteristics of shotcrete with several accelerator and chemical admixture types. These results indicate that shotcrete with alkali free accelerator and with superplasticizer are durable. Therefore, the present study provides a firm base to make high performance shotcrete.

발열이 있는 호중구 감소증 환자에서의 위험도 예측인자

정중식,권운용,김규석,임용수,이중의,서길준,윤여규 대한응급의학회 2000 대한응급의학회지 Vol.11 No.3

Background: Most febrile neutropenic patients are treated in an aggressive manner. However, identification of low-risk patients may enable clinicians to administer risk-based treatment. The object of this study is to certify the factors associated with increased risk at the time of visiting the emergency department. Methods: This is a retrospective study. We reviewed the medical records of 101 febrile neutropenic patients who had visited the emergency department of Seoul National University Hospital from January 1998 to August 1999. We assumed 22 risk prediction factors that could be assessed at admission to the emergency department and 5 factors that could be assessed during treatment course. To find independent risk-prediction factors, we analyzed these factors respectively by using multiple regression analysis. Results: Tachycardia(aOR=136.5), altered mentality(aOR=28.8), decreased renal function(aOR=20.1), and significant comorbidity(aOR=17,2) are the independent factors associated with higher mortality. Altered mentality(aOR=31.6) and decreased renal function(CCr < 75㎖/min, aOR=5.4) are those associated with a higher incidence of septic shock. Independent factors associated with persistent(more than 3 days) fever are the early(within 10 days) onset of fever after last chemotherapy(aOR=8.8) and the existence of new pulmonary infiltrates on a simple chest X-ray(aOR=4.3). Conclusion: The stability of vital signs, the change of mentality, the renal function, the existence of significant comorbidity, the existence of new pulmonary infiltrates, and the rate of neutropenia are clinically useful risk-prediction factors in febrile neutropenia at the time of visiting the emergency department.

초음파현미경의 고주파 초음파 탐촉자를 이용한 코발트기 초내열합금강의 열화평가

박익근,조동수,김용권,임재생,김정석 한국비파괴검사학회 2004 한국비파괴검사학회지 Vol.24 No.5

V(z)곡선법을 이용한 코발트기 초내열합금강의 열화도 평가 유용성 유무를 고주파 초음파 탐촉자를 이용하여 실험적으로 검증 하였다. 코발트기 초내열 합금이 고온에서 장시간 노출되었을 때 일어나는 미세조직의 변화를 모사하기 위해서 인공열화를 실시하였다. 여로하에 미치는 초음파 음속의 영향을 고찰하고자 10MHz를 이용하여 펄스-에코법으로 종파의 음속을 측정하고 200MHz를 사용하여 V(z)곡선법으로 누설턴성표면파의 음속을 측정하였다. 두 초음파의 음속은 열화시간에 따라서 감소 하였다. 더욱이, 저주파수 종파의 음속변화는 거의 없었지만, 고주파수 누설탄성표면파의 음속변화는 열화시간에 따라서 최대 4.7%의 변화를 나타내었다. 열화에 따른 강도의 변화와 누설탄성표면파의 음속 변화는 양호한 상관관계를 나타내었다. 따라서 열화도 평가에 고주파 탐촉자를 이용한 초음파 현미경의 V(z)곡선법이 유용함을 알 수 있었다. The feasibility of V(z) curve method of scanning acoustic microscope using high frequency transducer was experimentally studied for assessment of the thermal degradation in Co-based superalloy. Thermal degradation was performed to simulate the microstructural changes in Co-based superalloy arising trom long term exposure at high temperature. Longitudinal wave velocity measured by pulse echo method using 10MHz transducer and leaky surface acoustic wave (LSAW) velocity measured by V(z) curve method using 200MHz transducer were measured to investigate the effect on thermal degradation. Ultrasonic velocity decreased as the aging time increased in both ultrasonic waves. Moreover, the low frequency longitudinal wave velocity decreased a little. Otherwise, the high frequency LSAW velocity drastically decreased up to a maximum of 4.7% at the aging time of 4,000hours. A good correlation was found between LSAW and Vickers hardness. Consequently, V(z) curve method of SAM using high frequency transducer could be a potential tool for assessing thermal degradation.