• Title/Summary/Keyword: correlation measure

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The Influence of the Surface Roughness on the Natural Convection on a Vertical Flat Plate (수직평판의 거칠기가 자연대류 열전달에 미치는 영향)

  • Ohk, Seung-Min;Chung, Bum-Jin
    • Journal of Energy Engineering
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    • v.23 no.2
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    • pp.21-27
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    • 2014
  • The influence of the surface roughness on the natural convection heat transfers of a vertical plate were measured experimently. Mass transfer experiments instead of heat transfer experiment were performed based on the analogy. The piecewise electrodes were adopted to measure the local-average Nusselt number. Prandtl number was 2,014 and height of the plate was 0.154m The test results for a smooth surface showed similar heat transfer rate with the Le Fevre heat transfer correlation for a vertical plate. The Nusselt number increased with the roughness Rz $0.5{\sim}14.1{\mu}m$. The test results were presented by a simple correlation.

A Study of the Basic Bodice Pattern for Elementary Schoolgirls (학령기 어린이의 Bodice 기본원형에 관한 연구)

  • Lee Sook Nyeu;To Jai Un
    • Journal of the Korean Society of Clothing and Textiles
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    • v.6 no.2
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    • pp.57-67
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    • 1982
  • The purpose of this study was to improve the clothing life of the children between the nine to twelve by making a scientific and rational basic bodice pattern. The comparison of the eight pattern drafting currently used in Korea was referred in order to make new basic pattern. Three hundred fifty-two subjects from 9 to 12 years old in Seoul area were measured on 19 items. The measurements (24 items including 19 measured items and 5 drafted items that were difficult to measure) were analyzed by mean values and correlation coefficients between each item. This new pattern attempted to set the ease for clothing from experiments of the changes of body surface in motion. On the basis of the above results, a new bodice basic pattern was developed and tested with wearing three times. Through the experiments in measuring the changes of the body surface in motion, it was concluded that it desirable to set a standard of 12cm clothing ease on the bust circumference and 4cm on the waist circumference. The correlation coefficient of the tack width to across back was relatively high (r= .677), therefore, the latter measuring items were eliminated. A grading method was adopted to determine the width and depth of neckline and shoulder slope.

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The Influence of Likert Scale Format on Response Result, Validity, and Reliability of Scale -Using Scales Measuring Economic Shopping Orientation-

  • Kim, Sae-Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.6
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    • pp.913-927
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    • 2010
  • This study investigates the influence of Likert scale formats such as the number of response categories and the inclusion of a mid-point from a methodological point of view using instruments that measure a fashionmarketing-related subject. Using a self-administered questionnaire, 201 respondents rated their economic clothing shopping orientation on three formats of scales that differed only in the number of response categories (ranging from 5 to 7) from February 8 to February 12, 2010. Descriptive statistics, Spearman's rank order correlation, t-test, exploratory factor analysis, confirmatory factor analysis, Pearson's correlation, and Cronbach's alpha were used in the analysis. The results are as follows. First, three scale formats were generally suitable for use due to validity and reliability. Second, the response results varied with the number of categories and the inclusion of a mid-point, although the differences were statistically insignificant (with only a few cases that differed). Third, construct validity was more secure in scales with fewer categories, whereas convergent and discriminant validity was generally good in all scale formats. Fourth, reliability coefficients were higher in scales with more categories. Fifth, the number of categories was of greater importance to instrument design than the inclusion of a mid-point. Implications for appropriate scale designs are suggested in this study.

Measurement of Soil Organic Matter Using Near Infra-Red Reflectance (근적외선 반사도를 이용한 토양 유기물 함량 측정)

  • 조성인;배영민;양희성;최상현
    • Journal of Biosystems Engineering
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    • v.26 no.5
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    • pp.475-480
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    • 2001
  • Sensing soil organic matter is crucial for precision farming and environment friendly agriculture. Near infra-red(NIR) was utilized to measure the soil organic matter. Multivariate calibration methods, including stepwise multiple linear regression(MLR), principal components recession(PCR) and partial least squares regression(PLS), were applied to soil spectral reflectance data to predict the organic matter content. The effect of soil particle size and water content was studied. The range of soil organic matter contents was from 0.5 to 11%. Near infrared (NIR) region from 700 to 2,500nm was applied. For uniform soil particle size, result had good correlation (R$\^$2/ = 0.984, standard error of prediction= 0.596). The effect of soil particle size could be eliminated with 1st order derivative of the NIR signal. However. moist soil had a little lower correlation. R$\^$2/ was 0.95 and standard error of prediction was 0.94% using the PLS method. The results showed the possibility of soil organic matter measurement using NIR reflectance on the field.

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SVM-based Utterance Verification Using Various Confidence Measures (다양한 신뢰도 척도를 이용한 SVM 기반 발화검증 연구)

  • Kwon, Suk-Bong;Kim, Hoi-Rin;Kang, Jeom-Ja;Koo, Myong-Wan;Ryu, Chang-Sun
    • MALSORI
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    • no.60
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    • pp.165-180
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    • 2006
  • In this paper, we present several confidence measures (CM) for speech recognition systems to evaluate the reliability of recognition results. We propose heuristic CMs such as mean log-likelihood score, N-best word log-likelihood ratio, likelihood sequence fluctuation and likelihood ratio testing(LRT)-based CMs using several types of anti-models. Furthermore, we propose new algorithms to add weighting terms on phone-level log-likelihood ratio to merge word-level log-likelihood ratios. These weighting terms are computed from the distance between acoustic models and knowledge-based phoneme classifications. LRT-based CMs show better performance than heuristic CMs excessively, and LRT-based CMs using phonetic information show that the relative reduction in equal error rate ranges between $8{\sim}13%$ compared to the baseline LRT-based CMs. We use the support vector machine to fuse several CMs and improve the performance of utterance verification. From our experiments, we know that selection of CMs with low correlation is more effective than CMs with high correlation.

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A Study on the Development of Automatic Ship Berthing System (선박 자동접안시스템 구축을 위한 기초연구)

  • Kim, Y.B.;Choi, Y.W.;Chae, G.H.
    • Journal of Power System Engineering
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    • v.10 no.4
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    • pp.139-146
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    • 2006
  • In this paper vector code correlation(VCC) method and an algorithm to promote the image processing performance in building an effective measurement system using cameras are described for automatically berthing and controlling the ship equipped with side thrusters. In order to realize automatic ship berthing, it is indispensable that the berthing assistant system on the ship should continuously trace a target in the berth to measure the distance to the target and the ship attitude, such that we can make the ship move to the specified location. The considered system is made up of 4 apparatuses compounded from a CCD camera, a camera direction controller, a popular PC with a built in image processing board and a signal conversion unit connected to parallel port of the PC. The object of this paper is to reduce the image processing time so that the berthing system is able to ensure the safety schedule against risks during approaching to the berth. It could be achieved by composing the vector code image to utilize the gradient of an approximated plane found with the brightness of pixels forming a certain region in an image and verifying the effectiveness on a commonly used PC. From experimental results, it is clear that the proposed method can be applied to the measurement system for automatic ship berthing and has the image processing time of fourfold as compared with the typical template matching method.

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Assessment of Isometric Muscle Strength of Shoulder Girdle: A Reliability Study (어깨와 견갑대 근육의 등척성 근력 평가)

  • Hong, Wan-Sung;Kim, Gi-Won
    • The Journal of Korean Physical Therapy
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    • v.19 no.6
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    • pp.17-22
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    • 2007
  • Purpose: To evaluate the quantitative isometric muscle strength of shoulder girdle and the test reliability using by the equipment, named 'IsoTrack', selected by authors in the former studies. Methods: Thirty healthy subjects (9 men, 21 women) were recruited in two sessions, one for intratester and intertester reliability tests and the other quantitative isometric muscle strength tests. The neck flexion, extension and scapular elevation muscle strength was measured using a force measuring device as IsoTract. Results: Intraclass correlation coefficients for intratester reliability of the all subjects ranging between 0.96 and 0.97. For intertester reliability, the ICC and Pearson correlation correspond to 0.84 and 0.78. We gauged muscle strength of shoulder girdle muscles based on it and indicated quantified isometric muscle strength of women and men in left and right side. Conclusion: We concluded that there were high reiliability of isometric muscle strength of neck and shoulder girdle. Also, we gauged muscle strength of shoulder girdle muscles based on it and indicated quantified isometric muscle strength in left and right side in women and men. So this findings may assist in the measure of whole body muscle strength.

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Experimental study on analysis of correlation between void fraction and drag reduction rate in air lubrication ship (공기윤활선 모사 실험에서의 공극률 및 마찰저항저감율 상관성 분석을 위한 실험적 연구)

  • Park, Seungchan;Lee, Inwon
    • Journal of the Korean Society of Visualization
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    • v.18 no.1
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    • pp.11-17
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    • 2020
  • The reduction of CO2 emissions has been a key target in the marine industry since the IMO's MEPC published its findings in 2009. Air lubrication method is one of the mature technologies for commercialization to reduce the frictional resistance and enhance fuel efficiency of ships. Since the air lubrication pattern varies according to the ship's standing position and injection flow rate, in order to effectively control the air lubrication system, it is necessary to be able to judge the air layer development state based on the information collected from the monitoring sensor. In this study, we performed the air lubrication ship simulation experiment to measure the void fraction and the frictional resistance. The void fraction was measured to confirm the behavior of the air. Through the measurement of the frictional resistance, the change in frictional resistance reduction rate from the injection point to the longitudinal direction of the ship was confirmed. Based on the measurement results, correlation analysis was performed on void fraction and frictional resistance reduction rate.

Subjective Sleep Quality in Depressed and Non-Depressed Mothers During the Late Postpartum Period (산욕후기 모성의 산후우울 정도에 따른 주관적 수면의 질에 관한 연구)

  • Cho, Eun-Jung
    • Women's Health Nursing
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    • v.15 no.2
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    • pp.108-120
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    • 2009
  • Purpose: This study aimed to explore the subjective sleep quality of depressed and non-depressed mothers in the late postpartum period and to determine the relationship with their health promoting behaviors, family functioning, parenting stress. Method: A non-probability sample of 128 mothers completed a self-administered questionnaires at 4-6weeks postpartum. The Edinburgh postnatal Depression Scale (EPDS) and Pittsburgh Sleep Quality Index were used to measure mother's experiences of depression symptoms and sleep. Related factors of sleep quality were measured by the Korean Family Functioning Scale, Health Promoting Lifestyle Profile, and Parenting Stress Index. The data was analysed using t-test, one-way ANOVA, and the Pearson's correlation coefficients. Result: The results indicated that the depressed mothers (EPDS$\geq$ 10) had poorer sleep quality than the non-depressed mothers(EPDS < 10), reported shortened sleep duration, and experienced more daytime dysfunctions. Depressed mothers who had no job, did not drink coffee, and were primipara tended to report poorer sleep quality. There were significant correlation between poorer sleep quality and lower health promoting behaviors, higher family intimacy and lower family communication, and higher parenting stress among depressed mothers. Conclusion: Our findings support the view that depressed mothers' experiences of poor sleep are much higher than non-depressed mothers and multi-faced. Nurse professionals should screen for sleep problems in the depressed mothers with a different biopsychosocial and behavioral aspect from the non-depressed mothers in the late postpartum period.

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Correlations of Rice Grain Yields to Radiometric Estimates of Canopy Biomass as a Function of Growth Stage, : Hand-Held Radiometric Measurements of Two of the Thematic Mapper's Spectral Bands Indicate that the Forecasting of Rice Grain Yields is Feasible at Early to Mid Canopy Development Stages

  • Yang, Young-Kyu;Miller, Lee-D.
    • Korean Journal of Remote Sensing
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    • v.1 no.1
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    • pp.63-87
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    • 1985
  • Considerable experience has been reported on the use of spectral data to measure the canopy biomass of dryland grain crops and the use of these estimates to forecast subsequent grain yield. These basic procedures were retested to assess the use of the general process to forecasting grain yield for paddy rice. The use of the ratio of a multiband radiometer simulation of Thematic Mapper band 4(.76 to .90 .mu.m) divided by band 3 (.63 to .69 .mu.m) was tested to estimate the canopy biomass of paddy rice as a function of the stage of development of the rice. The correlation was found to be greatest (R = .94) at panicle differentiation about midway through the development cycle of the rice canopy. The use of this ratio of two spectral bands as a surrogate for canopy biomass was then tested for its correlation against final grain yield. These spectral estimates of canopy biomass produced the highest correlations with final grain yield (R = .87) when measured at the canopy development stages of panicle differentiation and heading. The impact of varying the amounts of supplemental nitrogen on the use of spectral measuremants of canopy biomass to estimate grain yield was also determined. The effect of the development of a significant amount of weed biomass in the rice canopy was also clearly detected.