• 제목/요약/키워드: Coefficients of Correlation

검색결과 4,608건 처리시간 0.033초

The Examination of Reliability of Lower Limb Joint Angles with Free Software ImageJ

  • Kim, Heung Youl
    • 대한인간공학회지
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    • 제34권6호
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    • pp.583-595
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    • 2015
  • Objective: The purpose of this study was to determine the reliability of lower limb joint angles computed with the software ImageJ during jumping movements. Background: Kinematics is the study of bodies in motion without regard to the forces or torques that may produce the motion. The most common method for collecting motion data uses an imaging and motion-caption system to record the 2D or 3D coordinates of markers attached to a moving object, followed by manual or automatic digitizing software. Above all, passive optical motion capture systems (e.g. Vicon system) have been regarded as the gold standards for collecting motion data. On the other hand, ImageJ is used widely for an image analysis as free software, and can collect the 2D coordinates of markers. Although much research has been carried out into the utilizations of the ImageJ software, little is known about their reliability. Method: Seven healthy female students participated as the subject in this study. Seventeen reflective markers were attached on the right and left lower limbs to measure two and three-dimensional joint angular motions. Jump performance was recorded by ten-vicon camera systems (250Hz) and one digital video camera (240Hz). The joint angles of the ankle and knee joints were calculated using 2D (ImageJ) and 3D (Vicon-MX) motion data, respectively. Results: Pearson's correlation coefficients between the two methods were calculated, and significance tests were conducted (${\alpha}=1%$). Correlation coefficients between the two were over 0.98. In Vicon-MX and ImageJ, there is no systematic error by examination of the validity using the Bland-Altman method, and all data are in the 95% limits of agreement. Conclusion: In this study, correlation coefficients are generally high, and the regression line is near the identical line. Therefore, it is considered that motion analysis using ImageJ is a useful tool for evaluation of human movements in various research areas. Application: This result can be utilized as a practical tool to analyze human performance in various fields.

Validity and reproducibility of a food frequency questionnaire to assess dietary nutrients for prevention and management of metabolic syndrome in Korea

  • Bae, Yun-Jung;Choi, Hae-Yeon;Sung, Mi-Kyung;Kim, Mi-Kyung;Choi, Mi-Kyeong
    • Nutrition Research and Practice
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    • 제4권2호
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    • pp.121-127
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    • 2010
  • Little data exists on metabolic syndrome (MetS) related with intake, especially for the South Korean. The purpose of this study was to develop and evaluate a food frequency questionnaire (FFQ) for nutritional assessment in the population with MetS in South Korea. Randomly selected female participants, mean age 21.9 years (n = 38) were invited to answer the FFQ twice (FFQ1 and FFQ2) over a nine-month interval and to complete twelve-day diet records (DR) during the months between in South Korea. The correlation coefficients for nutrient intake between FFQ1 and FFQ2 varied from 0.253 (niacin) to 0.573 (cholesterol), and the energy intake-adjusted correlation coefficients ranged from 0.187 for protein to 0.662 for iron. The energy intake-adjusted and de-attenuated correlation coefficients for comparison of FFQ1 and the DRs ranged between 0.277 (vitamin $B_1$) and 0.768 (fiber), and between 0.229 (zinc) and 0.859 (fat) for comparison of DRs with FFQ2. The percentages of study subjects classified into the same quartiles in both the DRs and FFQ1 ranged from 15.8% (vitamin $B_6$) to 47.4% (calcium), and for the same quartiles in DRs and FFQ2 from 13.2% (vitamin $B_1$) to 44.7% (potassium). The FFQ has reasonably good validity and reproducibility. Further research is needed for an assessment of reproducibility and validation of present FFQ in the subjects with MetS.

대기오염 모델의 정합도에 대한 연구: (서울특별시 대기오염추계에 있어 Hanna - Gifford Model과 Air Quality Display Model의 적용에 대하여) (The Validation of Air Pollution Simulation Models(comparisons between Hanna-Gifford Model and Air Quality Display Model in the Application to Air Pollution of Seoul))

  • 정용;장재연
    • 한국대기환경학회지
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    • 제2권1호
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    • pp.81-90
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    • 1986
  • Hanna - Gifford Model and Air Quality Display Model(AQDM) were validated in the simulation of $SO_2$ and TSP concentrations of Seoul City. The observed data which were measured at 16 sites of air monitoring system conducted by Seoul metropolitan city in 1984 were compared with the simulated data and the results were obtained as follows; 1. Several different meteorological data were examined: The particularities of meteorological data was not an influencing factor in the validity of simulation. The simulations of $SO_2$ by Hanna - Gifford model and by AQDM showed close correlation coefficients between the observed data and the simulated data (r = 0.71 - 0.78). 2. The simulation models showed different validities with the seasonal variation: The correlation coefficients (r) between the observed and the simulated by Hanna - Gifford Model for $SO_2$ and TSP were 0.86 and 0.80 in Spring, 0.63 and 0.66 in Summer, 0.76 in Autumn and 0.81 and 0.93 in Winter respectively. Those by AQDM were 0.73 and 0.68 in Spring, 0.56 and 0.79 in Summer, 0.77 and 0.76 in Autumn and 0.64 and 0.68 in Winter respectively. 3. The simulated data by two models had a close relationships: The correlation coefficients between them were 0.96 for $SO_2$, and 0.93 for TSP. With the above results, the application of models was discussed; Hanna - Gifford model was less valid in the simulation for the air quality of $SO_2$ and TSP in Seoul in Summer and AQDM also was not valid for $SO_2$ in Summer and in Winter and for TSP in Spring.

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한국인 50세 이상 성인과 노인을 위한 반정량 식품섭취빈도 조사지의 개발 및 타당도 검증 (Development and Validation of a Computerized Semi-Quantitative Food Frequency Questionnaire Program for Evaluating the Nutritional Status of the Korean Elderly)

  • 최혜미;이해정;박선주;김정희;김초일;장경자;임경숙;김경원
    • 대한지역사회영양학회지
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    • 제7권2호
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    • pp.277-285
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    • 2002
  • The purpose of this study was to develop a semi-quantitative food frequency questionnaire (SQ-FFQ) for subjects aged 50yr and over and to evaluate the validity of this SQ-FFQ. Dietary intake was assessed using SQ-FFQ that included 98 commonly consumed flood items selected from the results of the Korean Health and Nutritional Survey, 1998. Subjects (n = 2,660) aged 50yr and over were recruited from 7 metropolitan cities and 8 small cities. Each subject was interviewed using this SQ-FFQ developed in our laboratory and 24hr-recall method. Excluding incomplete data, Data from 1,149 subjects were used in this validity study. The nutrient intakes assessed by this SQ-FFQ were validated by comparing with the results from 1 day 24-hour recalls. Pearson's correlation coefficients between two methods were 0.71, 0.64, 0.53, and 0.43 for energy, carbohydrate, protein, and fat, respectively for all subjects. Spearman's correlation coefficients were higher than those of Pearson's correlation coefficients. Kappa values for energy, carbohydrate, protein, and fat were 0.79, 0.72, 0.70, and 0.64, respectively. The percentage for misclassification of the lowest quartile into the highest quartile or vice versa was 1.25-1.39% for all nutrients. Therefore, this SQ-FFQ seems to be useful in assessing the nutritional status of the middle-aged and elderly subjects in Korea.

원유내 체세포수 측정을 위한 Fossomatic과 Coulter Counter 방법의 비교 (Comparison of Fossomatic and Coulter Counter Methods for Somatic Cell Count in Raw Milk)

  • 이정구;손봉환;이정길;고홍범
    • 한국동물위생학회지
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    • 제16권1호
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    • pp.1-10
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    • 1993
  • Samples of bulk herd milk, foremilk, last milk (stripping) and individual cow sample were collected and their somatic cell number were counted with Fossomatic counter (FCC), Coulter counter(CC), direct microscopic somatic cell count(DMSCC) and Califormia mastitis test (CMT), The results were compared and summarized as follows : 1. Mean somatic cell counts of 120 bulk herd milk samples obtained by DMSCC, FCC and CC were 433,203, 481,213 and 676,245 respectively. 2. Mean somatic cell counts of 116 foremilk samples obtained by DMSCC, FCC and CC were 515,035, 611,845 and 725,051 respectively 3. Mean somatic cell counts of 87 last milk samples obtained by DMSCC, FCC and CC were 718,506, 839,874 and 1,041,160 respectively. 4. Mean somatic cell counts of 57 individual cow samples obtained by DMSCC, FCC and CC were 449,258, 491,018 and 521,315 respectively. 5. Mean somatic cell counts of all samples increased with the increasing CMT score, and the cell counts were higher by CC than by FCC. 6. The correlation coefficients between the somatic cell counts by CMT and CC were 0.926 in bulk herd milk, 0.707 in foremilk 0.688 in last milk and 0.675 in individual cow sample, respectively 7. The correlation coefficients between the somatic cell counts by CMT and FCC were 0. 945 in bulk herd milk, 0.705 in foremilk 0.694 in last milk and 0.727 in individual cow sample, respectively. 8. The correlation coefficients between the somatic cell counts by CC and FCC were 0.978 in bulk herd milk, 0.997 in foremilk 0.983 in last milk and 0.985 in individual cow sample, respectively.

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스피어만 장관계수를 이용한 사용자 상황 및 특성 처리 개선 (Improvement of User's Context Aware and Characteristic Process using spearman correlation coefficients)

  • 안찬식;오상엽
    • 한국멀티미디어학회논문지
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    • 제13권10호
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    • pp.1444-1452
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    • 2010
  • CRUMPET과 같은 모바일 단말기 서비스 시스템은 사용자의 상황과 특성이 사용자마다 서로 달라 정보가 매우 적고 이 또한 연관성을 찾기가 매우 어렵다. 사용자의 상황과 특성에 따른 정보 선호도를 제공하기 힘든 단점과 사용자가 원하는 정확한 정보를 추천하기 어렵기 때문에 개념적인 정보를 제한적으로 추천한다. 따라서 본 논문에서는 스피어만 상관 계수를 이용하여 사용자 상황과 특성에 적합한 정보를 추천하는 시스템을 제안하였다. 사용자 정보로부터 연관성을 찾아 서열화하고 사용자의 상황과 특성에 적합한 정보를 목록으로 제공하여 제한적인 개념적 정보 추천의 단점을 해결하였다. 성능 실험은 기존의 서비스 시스템들과 비교하여 효과성인 정확도와 재현율로 측정하였으며, 성능 실험 결과 정확도는 92.3%, 재현율은 73.8%로 나타났다.

The effects of the circulating water tunnel wall and support struts on hydrodynamic coefficients estimation for autonomous underwater vehicles

  • Huang, Hai;Zhou, Zexing;Li, Hongwei;Zhou, Hao;Xu, Yang
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제12권1호
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    • pp.1-10
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    • 2020
  • This paper investigates the influence of the Circulating Water Channel (CWC) side wall and support struts on the hydrodynamic coefficient prediction for Autonomous Underwater Vehicles (AUVs) experiments. Computational Fluid Dynamics (CFD) method has been used to model the CWC tests. The hydrodynamic coefficients estimated by CFD are compared with the prediction of experiments to verify the accuracy of simulations. In order to study the effect of side wall on the hydrodynamic characteristics of the AUV in full scale captive model tests, this paper uses the CWC non-dimensional width parameters to quantify the correlation between the CWC width and hydrodynamic coefficients of the chosen model. The result shows that the hydrodynamic coefficients tend to be constant with the CWC width parameters increasing. Moreover, the side wall has a greater effect than the struts.

비비등 선회유동에서의 2상 대류열전달 증가 (Two phase convective heat transfer augmentation in swirl flow with non-boiling)

  • 차경옥;김재근
    • 대한기계학회논문집
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    • 제19권10호
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    • pp.2586-2594
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    • 1995
  • Two phase flow phenomena are observed in many industrial facilities and make much importance of optimum design for nuclear power plant and various heat exchangers. This experimental study has been investigated the classification of the flow pattern, the local void distribution and convective heat transfer in swirl and non-swirl two phase flow under the isothermal and nonisothermal conditions. The convective heat transfer coefficients in the single phase water flow were measured and compared with the calculated results from the Sieder-Tate correlation. These coefficients were used for comparisons with the two-phase heat transfer coefficients in the flow orientations. The experimental results indicate, that the void probe signal and probability density function of void distribution can used into classify the flow patterns, no significant difference in voidage distribution was observed between isothermal and non-isothermal condition in non-swirl flow, the values of two phase heat transfer coefficients increase when superficial air velocities increase, and the enhancement of the values is observed to be most pronounced at the highest superficial water velocity in non-swirl flow. Also two phase heat transfer coefficients in swirl flow are increased when the twist ratios are decreased.

위.장관계 수술 환자간호의 질평가를 위한 도구개발 (Development of an evaluation tool of quality of nursing care for gastrointestinal surgery patient)

  • 이병숙;박정호;조현
    • 한국의료질향상학회지
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    • 제4권2호
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    • pp.260-278
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    • 1997
  • Background : Quality of professional nursing care is the most essential factor for survival and growth of nursing profession. Then, nursing professionals have responsibility for the evaluation of quality of professional nursing care. The purpose of this study was to develope an evaluation tool of nursing care for patients received gastrointestinal surgery with general anesthesia. This study was a primary work for the developement of a computer program for the evaluation of nursing care. Methods : This study was done through some consecutive steps. They were (1) Developement of items for the tool (2) Developement of an evaluation tool of nursing care quality for the G-I surgery patient (3) Test of reliability and validity of the tool. Two groups of experts and expert pannels who had much experience of the QA and the care of G-I surgery patients participated for developement of the items. 85 nursing records were used for the test of reliability and validity of the developed tool. The evaluation tools were developed with two types of scoring, norm-referenced tool and criterion-referenced tool. Results The system of items for tool was evaluation area evaluation item-indicator. There were 7evaluation areas which contained 32evaluation items which contained 7lindicators. Evaluation areas 1, 2, 3, 4 were for the evaluation of process and 5, 6, 7 were for the evaluation of outcome of nursing care for G-I surgery patient. For the test of interrator reliability, correlation coefficients of each scores of items and intragroup correlation coefficients were calculated. The average correlation coefficients between two rators were 0.65, 0.54 and the intragroup correlation coefficient were 0.99 and 1.00 by the types of scoring. The Cronbach alpha coefficients of the tools were 0.54 and 0.46 by the types of scoring. The average content validity index of the items was 0.95 from 4 pairs of experts. Because there were significant differences between some scores of quality of nursing care of 3 general hospitals regardless of the types of scoring, the tools could be thought to have some construct validity. And also, there were significant correlations between some scores of quality of nursing care and admission days and admission days after surgery regardless of the types of scoring, the tools could be thought to have predictive validity. Conclusion In this study, the evaluation tool of nursing care was developed for the very specified group of patient, G-I surgery patient. And the items were developed and tested by the experts of nursing practice. Because of these reasons, it was supposed that the tool could be used effectively in nursing pratice. And the procedures for the development and the test of the evaluation tool of nursing care in this study were supposed to be used for the developement of other tools.

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토양(土壤)의 화학적(化學的) 성질(性質)과 임목생장(林木生長)과의 관계(關係) (Relation between Chemical Properties of Soil and Tree Growth)

  • 정영관;홍병화;김종만
    • 한국산림과학회지
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    • 제46권1호
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    • pp.10-20
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    • 1980
  • 본연구(本硏究)는 토양(土壤)의 이화학적성질(理化學的性質)이 임목생장(林木生長)에 미치는 영향(影響)의 정도(程度)를 구명(究明)하여 적지(適地) 적수조림(適樹造林), 삼림생산예측(森林生産豫測) 등 합리적(合理的)인 임업경영(林業經營)을 유도(誘導)하고져 실시(實施)되었다. 대상수종(對象樹種)은 편백나무림(林) 78 plots를 선정(選定)하였다. 조사분석(調査分析)된 토양(土壤)의 이화학적성질(理化學的性質)은 토양(土壤)pH, 치환(置換)pH, 유기물(有機物), 전질소(全窒素), 유효(有效)$P_2O_5$, 치환성(置換性)$H^+$, 염기총량(塩基總量) 및 염기포화율(塩基飽和率)이며 흉고직경(胸高直徑), 수고(樹高) 및 재적생장량(材積生長量)을 외적기준(外的基準)으로 하였다. 측정치(測定値)의 통계적(統計的) 분석(分析)은 내부상관행열(內部相關行列), 중상관계수(重相關係數), 중회귀계수(重回歸係數), 편상관계수계산(偏相關係數計算) 과정(過程)으로 실시(實施)되어졌으며 결과(結果)를 요약(要約)하면 다음과 같다. 1. 토양(土壤)의 이화학적성질(理化學的性質)과 편백나무 흉고직경생장량(胸高直徑生長量)과의 회귀관계(回歸關係)에서 중상관계수(重相關係數)는 .364로서 추정효율(推定效率)이 낮았다. 그러나 염기총량(塩基總量), 토양(土壤)pH 그리고 염기포화율(塩基飽和率)은 임목생장(林木生長)에 기여(寄與)하고 있는 인자(因子)로 나타났다. 2. 수고생장량(樹高生長量)과 토양성질(土壤性質)과의 중상관계수(重相關係數)는 .443이며 관여인자(關與因子)는 흉고직경(胸高直徑)에 대(對)한 경우와 유사(類似)한 경향(傾向)을 나타내었다. 3. 재적생장량(材積生長量)과의 관계추정효율(關係推定效率)은 극(極)히 낮으나 염기총량(塩基總量)이 편백나무의 재적생장(材積生長)에 관여(關與)하는 인자(因子)로 나타났다. 따라서 편백나무생장(生長)에 관여(關與)하는 인자(因子)는 염기총량(塩基總量), 토양(土壤)pH, 염기포화율순(塩基飽和率順)이며, 토양(土壤)의 이화학적성질(理化學的性質)에 의(依)한 재적생장량(材積生長量) 추정효율(推定效率)은 극(極)히 낮으나 무입목지(無立木地)의 조림지(造林地) 선정(選定) 등에는 유용(有用)할 것으로 판단(判斷)된다.

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