• 제목/요약/키워드: frequency and correlation analysis

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포항지역 풍속전단 형태분석과 측정-보정-예측법의 응용 (Analysis of Wind Shear Patterns and Application of Measure-Correlate-Predict at Pohang Region)

  • 김현구
    • 신재생에너지
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    • 제1권2호
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    • pp.26-33
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    • 2005
  • This paper presents and overview analysis on the observed wind shear at Pohang Steel Works. focusing on diurnal patterns and the frequency of high nighttime shear at the site in case of land breeze. In addition, this paper discusses the importance of accurate shear estimation for reliable evaluation of wind energy density. In order for long-term correlation of the site, three Measure-Correlate-Predict methods were tested with Pohang wind data and it was shown that the linear MCP gives poor estimation due to the topological characteristics of complex terrain where the severe transformation of wind direction was accompanied.

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Analysis of Postural Stability During Continuous External Perturbations

  • Shin, Youngkyun;Park, Gu-Bum
    • 조명전기설비학회논문지
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    • 제27권8호
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    • pp.21-29
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    • 2013
  • The functional behaviors of human standing postural control were investigated when they were exposed to long-term horizontal vibration in the sagittal plane. For complexity of human postural control, a useful alternative method that has been based on a black-box approach was taken; that is, where the feedback mechanism was lumped into a single element. A motor-driven support platform was designed as a source of vibration. The AC Servo-controlled motors produced continuous anterior/posterior (AP) motion. The data were analyzed both in the time and frequency domain. The cross-correlation and coherency functions were estimated. Subjects behaved as a non-rigid pendulum with a mass and a spring throughout the whole period of the platform motion, as consistent with the plan chosen for this study.

불완전한 잡음 예측하에서 OFDM 시간 동기화 기법의 성능 분석 (Performance Analysis of OFDM Timing Synchronization Method with Imperfect Noise Estimation)

  • 이기창;윤영중
    • 한국통신학회논문지
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    • 제32권3C호
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    • pp.189-194
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    • 2007
  • 본 논문에서는 시간 동기 추정을 위한 잡음 예측이 불완전한 경우에 직교분할 주파수 다중화 (OFDM) 시스템의 시간 동기 확률을 다중 경로 레일레이 페이딩 채널 환경에서 분석한다. 시간 동기 방식은 반복되는 CAZAC 시퀀스에 대한 상관기 구조를 가지며, 심벌간 간섭을 줄이기 위한 pre-advancement 기법을 적용한다. 시스템의 성능 평가 척도로서, 다중 경로 레일레이 채널 환경에서 유도된 동기 검파 확률을 분석한다.

The detection of cavitation in hydraulic machines by use of ultrasonic signal analysis

  • Gruber, P.;Farhat, M.;Odermatt, P.;Etterlin, M.;Lerch, T.;Frei, M.
    • International Journal of Fluid Machinery and Systems
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    • 제8권4호
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    • pp.264-273
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    • 2015
  • This presentation describes an experimental approach for the detection of cavitation in hydraulic machines by use of ultrasonic signal analysis. Instead of using the high frequency pulses (typically 1MHz) only for transit time measurement different other signal characteristics are extracted from the individual signals and its correlation function with reference signals in order to gain knowledge of the water conditions. As the pulse repetition rate is high (typically 100Hz), statistical parameters can be extracted of the signals. The idea is to find patterns in the parameters by a classifier that can distinguish between the different water states. This classification scheme has been applied to different cavitation sections: a sphere in a water flow in circular tube at the HSLU in Lucerne, a NACA profile in a cavitation tunnel and two Francis model test turbines all at LMH in Lausanne. From the signal raw data several statistical parameters in the time and frequency domain as well as from the correlation function with reference signals have been determined. As classifiers two methods were used: neural feed forward networks and decision trees. For both classification methods realizations with lowest complexity as possible are of special interest. It is shown that two to three signal characteristics, two from the signal itself and one from the correlation function are in many cases sufficient for the detection capability. The final goal is to combine these results with operating point, vibration, acoustic emission and dynamic pressure information such that a distinction between dangerous and not dangerous cavitation is possible.

사회인구학적특성에 따른 운동중독과 정서의 관계 (An Analysis of Relation between Exercise Addiction and Affect to Sociodemographic Characteristics)

  • 현승권
    • 한국컴퓨터정보학회논문지
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    • 제15권6호
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    • pp.129-138
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    • 2010
  • 본 연구는 운동중독이 신체적, 정서적 삶의 질적 가치에 영향을 줄 수 있다는 전제하에 운동참여자의 사회인구학적특성에 따른 운동중독과 정서의 성향을 분석하고 운동중독과 정서는 어떠한 관련성이 있는지를 규명하여 운동참여자의 운동중독을 예방함과 동시에 합리적인 대처방안을 제시하고자 고찰하였다. 그 결과, 운동 참여자들은 테니스를 통하여 본인의 건강 유지 증진에 대한 심리적, 정서적 안녕감이 크게 작용하고 신체적인 기술성취의 중요성으로 인하여 운동중독현상과 더불어 긍정적, 부정적인 정서에도 유의한 영향을 미친다는 결과가 나타났다. 이러한 사실을 상기하여 각 개인에게 긍정적 참여행동을 주지시키는 것은 물론 지도자들은 테니스 운동 참여자들이 보다 긍정적인 운동수행이 되도록 운동 참여행동을 제시하고 이러한 행동을 지속적으로 수행해 나갈 수 있도록 하는 것이 건강을 위한 여가의 한 형태로서 테니스 운동참여가 이루어질 수 있는 올바른 방향이라 사료된다.

자기이미지와 니트웨어 선호도 및 착용빈도 연구 (Preference and Wearing Frequency of Knit-Wears Related to Self-Image)

  • 신윤경;이명희
    • 복식문화연구
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    • 제16권3호
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    • pp.518-532
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    • 2008
  • The purposes of this study were to investigate the relationships between women's self-image and the preference and the wearing frequency of knit-wears, and to examine the characteristics of the design elements that influence the preferred knit-wear images. The subjects were 277 female college students and working women living in metropolitan area of Seoul. The data were analyzed by using descriptive analysis, factor analysis, Cronbach's $\alpha$-reliability coefficient, Pearson's correlation coefficient, and multiple regression analysis. Four dimensions of women's self-images were derived by factor analysis; elegance, conservativeness, individuality, and maturity. Women with conservative self-image preferred simple knit-wears and women with high rate for individuality preferred splendid and sporty knit-wears. Women with elegant self-image disliked sporty knit-wears. Women with conservative self-image preferred white, and those who rated their self-image to be individuality preferred various colors including yellow, blue, green, purple, pink, and sky-blue. Women with mature self-image preferred black and beige. Women with individuality as their self-image preferred jacquard pattern and abstract pattern. There was a higher wearing frequency for all four seasons for women with conservative self-image, and there was higher wearing frequency in the winter for those with elegant self-images. Women who preferred simple knit-wears showed preference for single color with no prints and low chroma color, and those who preferred sporty knit-wears showed preference for elastic materials. Women who preferred neat and elegant knit-wears showed preference for argyle check pattern.

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일개 지역 영아의 수면 및 포유양상에 관한 연구 (Sleep and Feeding Patterns in Infancy)

  • 김영희
    • 여성건강간호학회지
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    • 제6권4호
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    • pp.566-578
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    • 2000
  • This study was conducted to ascertain infant's sleep and feeding patterns for the purpose of building up the positive parent-child relationship and setting up a preliminary parenting education program. The subjects were 16 infants who were cared for in their houses. The data was collected using NCASA developed by Barnard et al. from October 1st to December 3lth, 1999. The analysis of data was done with SPSSWIN for descriptive statistics and t-test, ANOVA, Correlation Analysis. The result were as follows: 1. The average day sleep of the infant was 9.51 hours, night sleep was 6.27 hours, and total sleep was 15.84 hours. The longest period of day sleep was 3.02 hours, and the longest period of night sleep was 3.72 hours. The regularity of day sleep was 34.78%, night sleep was 61.72% and total was 43.76%. 2. The frequency of daytime feeding was 5.13 times, nighttime was 2.44 times and total was 7.38 times. The regularity of feeding was 52.14%. 3. In the correlation between sleep and feeding patterns, night sleep was negatively correlated with feeding method(r=-.52, P<0.05), the longest period of day sleep was negatively correlated with feeding method(r=-.73, P<0.001), feeding frequency(r=-.60, P<0.05), the regularity of feeding(r=-.70, P<0.001). The longest period of night sleep was negatively correlated with feeding frequency (r=-.53, P<0.05). Feeding method was positively correlated with feeding frequency(r=.71, P<0.001), the regularity of feeding(r=.57, P<0.05). Day sleep was positively correlated with total sleep(r=.93, P<0.001), the regularity of total sleep was positively correlated with the longest period of day sleep(r=.54, P<0.05), total sleep(r=.65, P<0.001). The regularity of feeding was positively correlated with feeding method(r=.57, P<0.05), total feeding frequency(r=.50, P<0.05), the frequency of daytime feeding(r=.61, P<0.05). Feeding method was positively correlated with total feeding frequency(r=.71, P<0.001). In conclusion, the study showed that infants slept more in the nighttime than in the daytime, but after 3 months the pattern changed and showed that nighttime sleep was increased. Also the regularity of night sleep was increased with the infant's age. Total feeding frequency was decreased with the infant's age, and the regularity of feeding was increased in infants who slept shorter periods in the daytime than in the nighttime.

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멘토링이 멘티의 조직사회화에 미치는 영향 - 패션 머천다이저와 디자이너를 중심으로 - (The Perceived Effects of Mentoring on the Mentee's Organizational Socialization - Among the Fashion Merchandisers and Designers -)

  • 김민선;신용주
    • 대한가정학회지
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    • 제43권3호
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    • pp.75-89
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    • 2005
  • The purpose of this study was to examine the effects of the mentoring function and its levels as perceived by the fashion merchandisers and designers in the fashion industry who are playing major roles in providing organizational socialization for mentees. A survey questionnaire was developed and conducted among 200 fashion merchandisers and designers in Seoul. For data analysis, the SPSS 10.0 program was employed and frequency analysis, factor analysis, reliability analysis, correlation analysis, recurrence analysis, T-test, and ANOVA were used to test the research questions. The results were as follows: (1) Although the overall level of the mentoring function recognized by the fashion merchandisers and designers in the study appeared to be high, there were no significant differences by their demographic attributes. (2) The level of the mentoring function acknowledged by the respondents demonstrated substantial differences according to their perception by the personal attributes and the degree of openness. (3) The level of the mentoring function and organizational socialization perceived by the respondents had a significant correlation. As the level of perceived mentoring function of the respondents increased, it appeared that the degree of their job satisfaction and organizational commitment increased. On the other hand, their role ambiguity and turnover intention decreased.

포항지역 풍속전단 형태분석과 측정-보정-예측법의 응용 (Analysis of Wind Shear Patterns and Application of Measure-Correlate-Predict at Pohang Region)

  • 김현구
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2005년도 춘계학술대회
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    • pp.17-20
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    • 2005
  • This paper presents an overview analysis on the observed wind shear at Pohang Steel Works, focusing on diurnal patterns and the frequency of high nighttime shear at the site in case of land breeze. In addition, this paper discusses the importance of accurate shear estimates for reliable evaluation of wind energy density. In order for a long-term correlation of the site, three Measure-Correlate-Predict methods were tested with Pohang wind data and it was shown that the linear MCP gives poor estimation due to the geographic characteristics of complex terrain where the severe transformation of wind direction was accompanied.

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비건강 관련 학과 여대생의 건강증진생활양식과 영향요인 (A Study of Factors influencing Health Promotion Lifestyle in Women College Students)

  • 유경희;조경미
    • 한국간호교육학회지
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    • 제18권2호
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    • pp.343-352
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    • 2012
  • Purpose: The purpose of this study was to identify the factors influencing Health Promotion Lifestyle Profile of women college students. Methods: The sample consisted of 248 women college students in P city. Self report questionnaires were used to measure the variables. In data analysis, SPSSWIN 20.0 program was utilized for descriptive statistics, Pearson's correlation coefficients, and regression analysis. Results: The mean score for Health Promotion Lifestyle Profile was 2.27. In the the highest subcategories, the highest degree of performance was interpersonal relationships and the lowest degree was health responsibility. Health Promotion Lifestyle Profile was significantly different according to religion (F=3.48, p=.017), economic state(F=3.01,p=.031), perceived health state(F=8.07, p<.001), exercise frequency (F=16.02, p<.001), and self-rated knowledge about health (F=21.08, p<.001). In regression of analysis, perceived health state, exercise frequency, and self-rated knowledge about health were significant predictors explaining 30.5%. Conclusion: This study suggests that perceived health state, exercise frequency, and self-rated knowledge about health are significantly influencing factors in Health Promotion Lifestyle Profile in women college students. Therefore, the strategies of nursing intervention which improve these variables must be developed for women college students.