• 제목/요약/키워드: Long-range Correlation

검색결과 211건 처리시간 0.032초

뇌졸중 환자의 일상생활 수행능력, 신체상이 삶의 질에 미치는 영향: 대인관계 매개효과 중심 (Relationships of Activities of Daily Living and Body Image with Quality of Life in Stroke Patients: Mediating Effects of Interpersonal Relations)

  • 김민주;박효민
    • 근관절건강학회지
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    • 제28권2호
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    • pp.183-191
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    • 2021
  • Purpose: This study was conducted to identify factors associated with stroke patients' quality of life (QOL) and examine the mediating effects of interpersonal relations in the relationships of activities of daily living (ADL) and body image with QOL. Methods: In this study, 160 stroke patients were recruited from an outpatient clinic of a university hospital and rehabilitation clinic of a long-term care hospital. Participants completed a questionnaire which included sociodemographic characteristics, ADL, body image, interpersonal relation, and QOL. Descriptive statistics, t-tests, ANOVA, Pearson's correlation coefficients, multiple regression analysis, and process macro mediation analysis were conducted using SPSS. Results: The mean scores were 91.01 (range 6~100) for ADL, 61.19 (range 40~79) for body image, 87.53 (range 29~123) for interpersonal relations, and 186.67 (range 71~243) for QOL. Multiple regression analyses showed that ADL, body image, interpersonal relations, and participation in group activities after stroke were significantly associated with QOL among stroke patients (p<.05). There were no mediating effects of interpersonal relations in the relationships of ADL and body image with QOL (p>.05). Conclusion: This study showed that there is a need for physical, psychological, and social recovery to improve the QOL of stroke patients.

중국 대학생의 체질량지수에 따른 체력 비교 (Comparison of physical fitness according to body mass index of Chinese college students)

  • 정푸;김정현;김옥자
    • 대한물리치료과학회지
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    • 제28권3호
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    • pp.53-65
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    • 2021
  • Background: The purpose of this study was to a comparison of physical fitness according to the body mass index (BMI) of Chinese college students. Design: Cross-sectional study. Methods: According to the BMI, the research objects are divided into four types: underweight, normal weight, overweight, and obesity. This research took 26,976 college students who participated in Jiujiang College. It examines BMI, 50m, vital capacity, standing long jump, sitting forward bend, sit-up (female), pull-up (male), 800m (female), 1000m (male) which is to research the correlation between different BMI and other indicators. Results: The physical qualities of students with normal weight are significantly better than those with other BMI groups. Pearson correlation analysis showed that male BMI was positively correlated with vital capacity (r=0.07, p<0.01), 50m (r=0.15, p<0.01) and 1000m (r=0.14, p<0.01), and negatively correlated with standing long jump (r=-0.12, p<0.01), sitting forward bend (r=-0.06, p<0.01) and pull-up (r=-0.13, p<0.01); Female BMI was positively correlated with vital capacity (r=0.03, p<0.01), 50m (r=0.21, p<0.01) and 800m (r=0.18, p<0.01), and negatively correlated with standing long jump (r=-0.07, p<0.01), sitting forward bend (r=-0.11, p<0.01) and sit-up (r=-0.10, p<0.01). Conclusion: Overweight and underweight will affect the physical quality of college students. Students should keep their BMI within the normal range for their health.

수중에서 고속 기동하는 표적의 방위 탐지를 위한 최적의 청음기 배치 연구 (A Study on Optimal Hydrophone Arrangement for The Direction Finding of High Speed Moving Target in Underwater)

  • 한민수;최재용;강동석;손권;이필호
    • 한국군사과학기술학회지
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    • 제20권3호
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    • pp.369-375
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    • 2017
  • One of good DF(Direction Finding) methods is based on TDOA(Time Difference of Arrival) estimation when finding underwater moving target. For small DF error, high time resolution A/D(Analog-to-digital) conversion board and long baseline are needed. But the result of sea trial about close-range and high speed moving target, spatial correlation coefficient and appeared poor properties below 0.3 when hydrophone arrangement are separated over 6 ${\lambda}$ because of underwater fading channel. And we also find out that the distance between hydrophone should be under 4 ${\lambda}$ apart to take advantage of spatial correlation coefficient gain and performance of DF in underwater moving channel environments.

Elimination of environmental temperature effect from the variation of stay cable force based on simple temperature measurements

  • Chen, Chien-Chou;Wu, Wen-Hwa;Liu, Chun-Yan;Lai, Gwolong
    • Smart Structures and Systems
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    • 제19권2호
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    • pp.137-149
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    • 2017
  • Under the interference of the temperature effect, the alternation of cable force due to damages of a cable-stayed bridge could be difficult to distinguish. Considering the convenience and applicability in engineering practice, simple air or cable temperature measurements are adopted in the current study for the exclusion of temperature effect from the variation of cable force. Using the data collected from Ai-Lan Bridge located in central Taiwan, this work applies the ensemble empirical mode decomposition to process the time histories of cable force, air temperature, and cable temperature. It is evidently observed that the cable force and both types of temperature can all be categorized as the daily variation, long-term variation, and high-frequency noise in the order of decreasing weight. Moreover, the correlation analysis conducted for the decomposed variations of all these three quantities undoubtedly indicates that the daily and long-term variations with different time shifts have to be distinguished for accurately evaluating the temperature effect on the variation of cable force. Finally, consistent results in reducing the range of cable force variation after the elimination of temperature effect confirm the validity and stability of the developed method.

산지유역에 대한 USDAHL-74 유역수문모형의 장기유출 해석적용 (Application of SDAHL-74 Watershed Model to a Long Term Runoff Analysis in the Mountainous Watershed)

  • 권순국;고덕구
    • 한국농공학회지
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    • 제29권2호
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    • pp.53-63
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    • 1987
  • Due to their wide range of application, deterministic comprehensive hydrologic models using digital computers have been developed in all countries of the world and researches are being undertaken for their appropriate applications. The aim of this study has been to demonstrate the practical implementation of a physically based distributed hydrologic model, the USDAHL-74 model and to investigate its ability to simulate the long term estimate of water balance quantities in a Korean mountainous watershed. Application of the model to Dochuk watershed indicates the following results. 1.Since the USDAHL-74 model includes all the major components of the hydrologic cycle in agricultural watersheds, thus is comprehnsive, the model seems to have a wide range of application from the fact that simulation results obtained are not only runoff volumes m various time units but their spatial variation as well as even soil moisture within the watershed. 2.An approximate calibration to determine the parameter values in the model using various data obtained from D0chuk shed shows that the simulation error of yearly runoff volume is only 0.6 % and a correlation coefficient between observed daily runoff volume and simulated one is 0.91 in all calibrated period.3.As a verification test of the model, runoff volumes are simulated using 1986 year data without changing the parameter values determined by 1985 year data. The tests show that the USDAHL-74 model is a flexible tool and that realistic production to simulate the long term estimate of runoff in Korean mountainous watershed could be obtained using only a short period of calibration.4. Despite of the encouraging results, there still remain minor problems concerning the practical application of the model to improve the result of simulations. Some of these are the small descrepancies between observed and simulated daily runoff volume appeared in the vicinity of peaks and the recession of1 the daily hydrographs and the model performance for the frozen ground and melting process in the model. 5. Alough the use of parameter with physical significance and the ability to improve calibrations on the basis of physical reasoning represents advantages in the simulation for ungaged watersheds, further researches are needed to use the USDAHL-74 mode to simulate runoff in ungaged watersheds.

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원격모니터링을 이용한 연속파랑관측에 관한 연구 (A Study on Continuous long-term Wave Observation using Remote Monitoring System)

  • 신범식
    • 한국산학기술학회논문지
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    • 제19권1호
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    • pp.654-659
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    • 2018
  • 본 연구에서는 연안 환경에 대한 대표적인 지상 원격 관측 기기인 Ocean Radar를 이용하여 장기파랑관측을 수행하였다. 지상에 설치한 기기로부터 이루어지는 원격 관측은 소수의 현장 기기 개수로는 관측할 수 없는 넓은 범위의 해역을 통시에 관측할 수 있고 또한 높은 빈도의 지속적인 관측이 가능한 장점이 있다. 장기관측을 위한 Ocean Radar는 과거 지진해일에 의한 피해가 발생하고, 원자력 발전소가 위치한 한국 동해안의 삼척지역에 대해 장기관측을 수행하였으며, 원격관측의 적용성을 검토하기 위해 수압식 파고계를 설치하여 각각의 조사자료를 비교하였다. 원격파랑관측은 연구대상해역 전면에 독일 Helzel사에서 개발된 Array type의 HF-RADAR인 WERA (WavE RAdar)를 2개소에 설치하여 자료를 취득하였으며, 장기간 연속된 관측된 자료의 취득률을 분석해본 결과, Ocean Radar 가 설치된 두 Site의 중심에서 약 24km이며, 약 27km의 범위 내에서는 Wave 자료가 90% 이상 취득되었으며, 시계열로 분석한 결과, 결측된 시간이 전체 계측기간의 1% 미만이다. 직접관측방식인 수압식 파고계와 관측자료를 비교한 결과, RMS 편차는 20cm 이내이며, 상관계수가 0.84 ~ 0.87로 높은 상관관계를 가지는 것으로 분석되었다. 따라서, 금회적용한 Ocean Radar는 기존의 파랑 계측 장비를 대체하여 장기간 면적 파랑관측이 가능할 것으로 생각된다.

장기하중을 받는 바닥완충재의 처짐 예측 평가 (Evaluation on Expectation of Deflection of Floor Damping Materials Subjected to Long-Term Load)

  • 김정민;홍윤기;김진구;이정윤
    • 한국구조물진단유지관리공학회 논문집
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    • 제20권4호
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    • pp.19-26
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    • 2016
  • 최근 층간소음을 저감시키기 위하여 밀도와 동탄성계수가 낮은 바닥완충재를 뜬바닥구조에 사용하며, 이로 인하여 바닥완충재의 처짐 및 상부 마감몰탈의 균열이 발생할 가능성이 높아지고 있다. 이 연구에서는 층간소음 저감을 위하여 사용되는 바닥완충재의 장기처짐을 실험을 통하여 평가하였다. 완충재의 재질, 하부형상, 밀도, 가력하중을 변수로 하는 16개의 바닥완충재에 대하여 490일간의 장기처짐 실험을 하였다. 실험에 의하면 완충재의 장기처짐은 하중가력 200일 시점 이후로 일정한 경향을 보였다. 예외적으로 Polystyrene 재질의 완충재 경우, 250 N 하중재하에서는 160일, 500 N 하중재하에서는 100일 이후로 일정한 경향을 보였다. 이 연구에서는 처짐이 일정해지는 구간을 제외한 증가 구간에 대해 두 가지의 장기처짐 평가식을 작성하였으며, 각각 ISO 20392와 실험값의 추세를 이용한 선형회귀 분석을 이용하였다. 두 평가식과 실험값과의 비교분석에서 처짐량이 10 mm 이하의 경우, ISO 20392와 실험값의 추세를 이용한 선형회귀 분석 방법 모두 오차 0.4 mm 이하로 실제 처짐과 유사하게 나타났다. 단, Polystyrene 재질의 완충재 경우, ISO 20392에 의한 처짐 분석 방법이 더 적절한 것으로 판단되었다.

UAV 영상과 ENVI-met 활용 물리적 환경과 열적 환경 비교 (Comparing Physical and Thermal Environments Using UAV Imagery and ENVI-met)

  • 김성현;박경훈;송봉근
    • 한국지리정보학회지
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    • 제26권4호
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    • pp.145-160
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    • 2023
  • 본 연구는 무인항공기(Unmanned Aerial Vehicles, UAV) 기반 물리적 환경인 Normalized Difference Vegetation Index(NDVI), Sky View Factor(SVF)와 ENVI-met 모델링을 활용하여 시간대별 열적 환경을 비교 분석하는 것을 목적으로 수행하였다. 연구 결과 NDVI, SVF는 열적 환경 요소인 Upward short-wavelength(S↑), Downward short-wavelength(S↓), Upward long-wavelength(L↑), Downward long-wavelength(L↓), Land Surface Temperature (LST), Mean Radiant Temperature(Tmrt)와 유의수준 1% 이내에서 모두 상관관계를 보이는 것으로 도출되었다. 특히, NDVI는 S↑와 12시에 최대 -0.52**의 상관관계를 가지는 것으로 분석되었고, L↓와 모든 시간대에서 0.53** 이상의 상관성을 보였다. LST와는 -0.61**(13시)의 상관성을 보여 NDVI는 장파 복사에너지의 관련성이 높은 것으로 판단된다. SVF의 경우 SVF 범위에 따라 장파 복사에너지와의 관련성이 높은 것으로 도출되었다. 본 연구결과는 공간의 열적 쾌적성과 미기후를 평가하기 위한 통합 접근 방식을 제공할 수 있으며, 도시 디자인 및 경관 특성이 보행자의 열 쾌적성 미치는 영향 관계 규명 등에 활용될 수 있을 것으로 판단된다.

상호상관 행렬을 이용한 선배열 빔형성 기법 연구 (A Study on the Linear Array Beamforming by Cross Correlation Matrix)

  • 황수복;이성은
    • 한국음향학회지
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    • 제20권7호
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    • pp.31-36
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    • 2001
  • 수동 소나 시스템에서는 신호대 잡음비의 향상, 표적의 방위 탐지 및 위치 데이터 산출, 간섭신호 제거 등을 위하여 지향성 빔을 만들어 사용한다. 주변환경이 복잡한 해양에서 저소음의 표적을 원거리에서 탐지하기 위해서는 지향성 빔의 특성을 향상시킬 필요가 있다. 본 논문에서는 선형으로 배열된 센서에서 각 센서 쌍들의 상호상관 행렬을 이용한 SCCBF (Spatial Cross Correlation Beamforming) 알고리즘을 제안하였다. 이상적인 조건하에서 제안된 SCCBF는 기존의 CBF (Conventional Beamforming)에 비해 배열 이득이 3 dB 이상 향상되고 표적의 탐지 방위 정확도를 나타내는 빔 폭이 CBF보다 0.5배 정도가 됨을 이론적으로 검증하고, 시뮬레이션을 통하여 이를 입증하였다. 또한 제안된 알고리즘을 적용한 선배열 수동 소나 시스템의 해상 시험 결과를 제시하였다.

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제주지역 미세먼지의 장기변동 및 농도변화에 관한 국지기상 분석 (An Analysis of Long-Term Variation of PM10 Levels and Local Meteorology in Relation to Their Concentration Changes in Jeju)

  • 박연희;송상근;이수정;김석우;한승범
    • 한국환경과학회지
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    • 제25권1호
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    • pp.107-125
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    • 2016
  • Long-term variations of $PM_{10}$ and the characteristics of local meteorology related to its concentration changes were analyzed at 4 air quality sites (Ido-dong, Yeon-dong, Donghong-dong, and Gosan) in Jeju during two different periods, such as PI (2001-2006) and PII (2007-2013), over a 13-year period. Overall, the long-term trend of $PM_{10}$ was very slightly downward during the whole study period, while the high $PM_{10}$ concentrations in PII were observed more frequently than those in PI. The concentration variations of $PM_{10}$ during the study period was clarified in correlation between $PM_{10}$ and meteorological variables, e.g. the low (high) $PM_{10}$ concentration with large (small) precipitation or high (low) radiation and in part high $PM_{10}$ concentrations (especially, Donghong-dong and Gosan) with strong wind speed and the westerly/northwesterly winds. This was likely to be caused by the transport effect (from the polluted regions of China) rather than the contribution of local emission sources. The $PM_{10}$ concentrations in "Asian dust" and "Haze" weather types were higher, whereas those in "Precipitation", "Fog", and "Thunder and Lighting" weather types were lower. The contribution of long-range transport to the observed $PM_{10}$ levels in the urban center (Ido-dong, Yeon-dong, and Donghong-dong), if estimated by comparison to the data of the background site (Gosan), was found to explain about 80% (on average) of its input.