• 제목/요약/키워드: Degree of Frequency

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비동기 히브 및 피치 운동에 따른 에어포일 비정상 공력 특성 Part 2 : 피치 진동운동 진폭 (Unsteady Aerodynamic Characteristics of an Non-Synchronous Heaving and Pitching Airfoil Part 2 : Pitching Amplitude)

  • 지승환;한철희
    • 항공우주시스템공학회지
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    • 제17권6호
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    • pp.63-71
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    • 2023
  • 본 연구에서는 NACA 0012 에어포일을 사용하여 히브와 피치 진동운동의 주파수가 다른 경우에 대하여 피치진동운동의 진폭에 에어포일의 비정상 공력 특성에 미치는 영향을 수치적으로 연구했다. 양력계수는 주파수비가 1.0인 경우 피치진동운동의 진폭이 30°와 20°인 경우 양력계수 값이 크지 않았으나 10°인 경우 양력계수값이 크게 증가했다. 주파수비가 0.5인 경우 양력계수값은 전체적으로 주파수비가 1.0인 경우보다 큰 값을 가졌으며, 진폭이 감소할수록 양력이 크게 증가하였다. 항력계수는 주파수비가 1.0인 경우 전체적으로 추력이 크게 발생하였으며 진폭이 감소할수록 추력의 크기가 감소하였다. 주파수비가 0.5인 경우 피치진동운동의 진폭이 30°인 경우 항력이 발생하였으나 진폭이 10°인 경우 추력이 발생하였다. 향후 본 연구를 확장하여 에어포일의 히브진동운동의 진폭변화에 따른 비정상 공력 특성 변화를 연구할 계획이다.

남.녀 중학생의 식생활관리 단원에 대한 관심도 및 실행 능력 (A Study on Interest and Application Ability in Meal Management of the middle School Students)

  • 이광희;임양순
    • 한국생활과학회지
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    • 제9권3호
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    • pp.383-394
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    • 2000
  • The purpose of this study was to investigate the degree of interest and application ability in meal management chapters of the middle school students, and to provide basic informations for the improvements of Home Economics curriculum and teaching projects. The subjects were 555 middle school students(275 males, 280 females) in Chunchon area, Kangwon-do. Research data were collected by means of the questionnaire and statistically analyzed by frequency, percentage, standard deviation, t-test, F-test and correlation analysis using SPSS/win. The results of this study were summarized as follows: There were significant differences in the degree of interest and application ability according to gender, school years, home economics scholastic achievements, and father's role in preparing meal. The degree of interest and application ability was significantly higher in female than male. First grade students showed more interest and higher application ability than the third year. In general, the higher home economics scholastic achievement was, the higher the degree of interest and application ability was. The more father's role was in preparing meal, the higher student's degree of interest and application ability was. There was significant correlation between the degree of interest and the degree of application ability.(r=0.853, p< .001)

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류마티스 관절염 환자의 통증대처, 통증 및 우울정도의 관계 (The Relationship among the degrees of pain coping strategies, Pain and Depression of patients with Rheumatoid Arthritis)

  • 박경;최순희
    • 근관절건강학회지
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    • 제5권2호
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    • pp.253-264
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    • 1998
  • This study has done for the purpose of investigation among the degrees of pain coping strategies, pain, and depression of patients with rheumatoid arthritis. The subjects of this study were 214 patients diagnosed with rheumatoid arthritis. The data were collected from september 4 to 16, 1995 by questionnaires. The data were analysed by the use of frequency, t-test, Pearson Correlation Coefficients, ANOVA, and Duncan test. The results Were as follows ; 1. The mean score of pain was 213.5(range : 4-390) and that of depression was 21.4 (range : 1-50). The mean score of passive pain coping strategies was 30.2(range : 11-48) and that of active pain coping strategies was 18.6(range : 7-33) 2. The passive pain coping degree showed a positive correlation with the pain degree (r=.475, p=.0001) and the active pain coping degree showed a inversive correlation with that(r= -.296, p=.0001). The passive pain coping degree showed a positive correlation with the depression degree (r=.425, p=.0001) and the active pain coping degree showed a inversive correlation with that(r=-.299, p=.0001). The pain degree showed a positive correlation with the depression degree(r=.374, p=.0001).

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Application of frequency domain analysis for generation of seismic floor response spectra

  • Ghosh, A.K.
    • Structural Engineering and Mechanics
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    • 제10권1호
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    • pp.17-26
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    • 2000
  • This paper presents a case study with a multi-degree-of-freedom (MDOF) system where the Floor Response Spectra (FRS) have been derived from a large ensemble of ground motion accelerograms. The FRS are evaluated by the frequency response function which is calculated numerically. The advantage of this scheme over a repetitive time-history analysis of the entire structure for each accelerogram of the set has been highlighted. The present procedure permits generation of FRS with a specified probability of exceedence.

고속전철 액슬 기어박스 현가계의 고유 진동수 측정 (Finding-out the Natural Frequency of the Axle Gearbox Suspension System of the High-speed Train)

  • 최진욱;차수덕;김용기;이태화
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2001년도 추계학술대회 논문집
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    • pp.163-170
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    • 2001
  • Axle Gearbox of the High Speed Train has rotational degree of freedom centered on the Axle Shaft Center Line, and constrained by the Reaction Arm connected to the Bogie Frame via Resilient Ring made of Rubber. This System is laid on the Power Train and can influence on the Power transmitted from Motor to Axle. The stiffeness of the Resilient Ring have to be selected for the Natural Frequency of this System do not overlap with the Teeth-mating Frequency. To confirm the Design Parameters, Calculation and Experiment were executed and compared.

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우리나라 동남부 일강수량의 도수분포곡선

  • 김석중
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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    • pp.207-210
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    • 2003
  • In this research analyzed the daily precipitation depths of 4 climatic stations in south eastern part of Korea. It aimed to present some indices for regionalization of the area. The items are frequency distributions of precipitation quantity and days and the longest days less than class limit set up by arithmetic differences. The regression analysis between class value and frequency show very good correlation coefficients better than 0.99 which are cubic equation for the precipitation, exponential equation for the precipitation days, and first degree equation for the longest day less than class limit.

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카오스 특성에 의한 뇌의 활동도 분석 (Brain activity analysis by using chaotic characteristics)

  • 김택수;김현술;박상희
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.1844-1847
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    • 1997
  • Assuming that EEG(electroencephalogram), which is generated by a nonlinear electrical of billions of neurons in the brain, has chaotic characteristics, it is confirmend by frequency spectrum analysis, log frequency spectrum analysis, correlation dimension analysis and Lyapunov exponents analysis. Some chaotic characteristics are related to the degree of brain activity. The slope of log frequency spectrum increases and the correlation dimension decreasess with respect to the activities, while the largest Lyapunov exponent has only a rough correlation.

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Soy food intake behavior by socio-demographic characteristics of Korean housewives

  • Lee, Min-June;Park, Ok-Jin
    • Nutrition Research and Practice
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    • 제2권4호
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    • pp.275-282
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    • 2008
  • In this study, the soy food intake behaviors including perception and intake frequency of soybean foods by sociodemographic variables were analyzed in housewives. The perception of housewives for soy foods showed that soybean paste, soybean curd, and Dambuk were high in the descending order for nutritional quality and health promotion effect, and soybean paste received the highest score in taste and flavor. Soybean sprouts received the highest evaluation score in the economic aspect. In the aspect of safe food, soybean paste received the highest evaluation score, as mush as a traditional food. The analysis of perception by sociodemographic variables showed that soybean curd, Dambuk, and soybean sprouts had higher perceptions as education level increased, and soy milk had higher perceptions in subjects with younger age and with employment. In the intake frequency, more than 50% of the subjects had soybean curd, soybean sprouts, and soybean paste more than once a week. The analysis for correlation between the intake frequency of soy foods and the degree of perception showed that taste and flavor had high correlation with the intake frequency of soy foods except soybean sprouts. The intake frequency of soybean paste, Dambuk, and soy milk had positive correlations to familiarity and that of soy milk had positive correlations to nutrition and health perception, and those of soybeam paste, soybean sprouts, and soy milk had positive correlations to safe food perception. From the above results, housewives in Korea had very high perceptions to nutritional quality and health promotion effect of soy foods and the degree of perception and accompanied intake frequency had significant differences by age, education level, and economic level among sociodemographic variables.

노출빈도와 인지도 관계에 따른 정보의 유형과 표현기법 (Information Types and Display Methods according to the Relation between Frequency of Exposure and Degree of Cognition)

  • 한지애;류시천
    • 디지털융복합연구
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    • 제10권10호
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    • pp.497-504
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    • 2012
  • 본 연구는 사용자의 인지적 측면에서 정보의 효율성을 높이기 위한 고찰로써, 정보의 노출빈도와 인지도의 관계에 따른 정보의 유형과 속성에 따른 표현 기법을 제안하였다. 인지공학과 인지심리학 분야의 문헌연구를 통해 노출빈도와 인지도의 상관관계를 규명하였고, 이를 바탕으로 다음과 같은 연구결과를 얻었다. 첫째, 사용자의 인지적 요구를 파악 할 수 있도록 하는 '프레임웍'으로써의 정보유형과 유형별 시각화 속성을 제안하였다. 세부적으로 정보 노출 빈도와 정보의 인지도에 따른 STM, STA, LTM, LTA 4가지 정보 유형과 각 유형에 관한 인지적 특성, 14가지 고품질 정보의 시각화 속성을 유형별로 재분류한 '시각화 속성 매트릭스'를 제안하였다. 둘째, 정보 콘텐츠 제작에 있어서 필요한 정보 깊이에 따른 표상방식에 대한 가이드라인을 제안하였다. 1차적 정보로서 STM, STA 정보의 표현기법으로 "독특속성", "선행 조직자(Advance Organizer)", "단계적 정보공개(Progress Closure)", "행위유발단서(Affordance)"를 제안하였으며, 다차원 정보로서 LTM 정보 표현기법으로 "모듈방식(Modularity)", "일관성(Consistency)", "모방(Mimicry)", "기억술(Mnemonic Device)"를 제안하였다. 본 연구를 통한 주요 발견점으로 정보의 유형과 깊이에 따라 정보의 시각화 속성의 중요도에 차이가 나타나며, 이에 따라 정보 표현기법이 달라 질 수 있음을 발견하였다.

산후조리원 이용 산모의 산후조리 인지도와 수행도 (A Study on the Level of Recognition & Performance of Traditional Postpartal Care for postpartal Women in Postpartum Care Center)

  • 박심훈;김현옥
    • 여성건강간호학회지
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    • 제8권4호
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    • pp.506-520
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    • 2002
  • The purpose of this study is to research the degree of recognition & performance of traditional postpartal care for postpartal women and to provide the basic data for improvement of service in a postpartum care center. The respondents of this study were 100 women of 6 postpartum care centers within a C province from Oct. 20 to Dec. 10, 2000. The instruments of measure were used for collecting data on the degree of recognition & performance of traditional postpartal care developed by the researcher. Data analysis consisted of frequency, percentage, mean, standard deviation, paired t-test, t-test, ANOVA which are calculated by Scheffe test and Cronbach's alpha which is used as a reliance level by using a SPSS-PC+. The results of the study were as follows:1. The average score for the degree of recognition of traditional postpartal care(Sanhujori) for postpartal women was $3.09{\pm}.31$, and they recognized that it was important. The methods which were ranked were as follows; Protecting the body from a harmful state, invigorating the body by the argumentation of heat and avoidance of cold, handling with whole heart, and keeping clean, resting without working, eating well. 2. The average score for the degree of performance of traditional postpartal care (Sanhujori) for postpartal women was $2.81{\pm}.31$, and they performed that it was important, too. The methods which were ranked were as follows; Protecting the body from a harmful state, invigorating the body by the augumentation of heat and avoidance of cold, eating well, handling with whole heart, and keeping clean, resting without working. 3. There were significant differences statistically (paired-t=-8.39, p=.000) of the degree of recognition & performance of traditional postpartal care(Sanhujori) for the postpartal women. The degree of recognition was higher than the degree of performance. So, the recognition of traditional postpartal care (Sanhujori) was higher than the performance of it. 4. There were no statistical differences of the degree of recognition & performance of traditional postpartal care(Sanhujori) among the postpartal women's age, religion, job, educational background, delivery frequency, delivery method or the sex of baby. So, the Characteristics of the respondents were not influenced as far as the degree of recognition & performance of traditional postpartal care(Sanhujori). 5. There were significant differences statistically of the degree of performance of traditional postpartal care(Sanhujori) among the 5 postpartum care centers except 1 postpartum care center(p<.01). So, the recognition of traditional postpartal care(Sanhujori) was higher than the performance of traditional postpartal care(Sanhujori) in the 5 postpartum care centers. But there was performed as good as recognition in only 1 postpartum care center.

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