• Journal of Mechanical Science and Technology
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• 제14권3호
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• pp.261-271
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• 2000

In this paper the leakage prediction and rotordynamic analysis of an annular seal with a smooth rotor and circumferentially grooved stator are performed based on a three-controlvolume theory. The present analysis is validated by comparing with the experimental data of Iwatsubo and Sheng and theoretical results suggested by Marquette and Childs. For the leakage prediction the present analysis shows a good agreement with Marquette and Childs' result and a qualitation agreement with Iwatsubo and Shengs' experimental data. Direct and cross-coupled stiffness coefficients show closer agreement with the experimental values than those of Marquette and Childs. However, direct damping coefficient shows greater discrepancy from the experimental value than Marquette and Childs'.

• 한국지능시스템학회논문지
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• 제21권1호
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• pp.1-5
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• 2011

우리는 동의지수법에 의한 이변량정규분포의 변수 간 독립성에 대한 퍼지 상관 검정법을 제안하였다. 이를 위하여 퍼지 데이터의 조건을 제시하고, 퍼지 상관계수와 가설을 기각하고 채택할 정도를 위한 동의지수법을 정의하였다. 또한 예증을 위하여 한 이변량정규분포로부터 퍼지 표본을 추출하여 퍼지 상관계수를 이용한 최강력 불편 퍼지 검정법을 보였다.

• 한국해안·해양공학회논문집
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• 제20권6호
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• pp.532-539
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• 2008

권 등(2008)은 수면보다 높은 사각기둥 저항체를 등간격으로 배치하고 항력계수가 일정한 값을 갖는 흐름조건$(Re>10^4)$에서 수리실험을 수행하여 바닥마찰과 형상저항에 의한 흐름저항을 나타내는 상당저항계수로서의 Manning계수 값을 산정하였다. 그리고 힘의 평형방정식으로부터 유도된 이론식에 실험결과를 사용하여 얻어진 경험적 항력상호작용계수를 도입하여 얻은 상당저항계수 식을 제안하였다. 본 연구에서는 이 수리실험을 3차원 전산유체해석 프로그램인 FLOW-3D를 사용하여 수치모의하고 그 결과를 실험결과 및 상당저항계수 식과 비교하여, 그값들이 매우 잘 일치하는 것을 보였다. 이로부터 이론식에 나타나 있는 것처럼 수면보다 높은 저항체가 존재할때 Manning계수가 수심의 2/3승으로 증가한다는 것과 항력상호작용계수가 이격거리의 지배적 영향을 받고 있음을 확인할 수 있었다.

• 대한지역사회영양학회지
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• 제16권3호
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• pp.307-314
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• 2011

The purpose of this study is finding the easy way of 4 categories activity level confirmation for estimated energy requirement calculation. Total of 386, 5th and 6th grade primary school students participated. The time spent on 7 kinds of activity were collected for 1 day by the internet program developed. Judged by the activity coefficient, sedentary were 6.7% and 5.1%, low active 33.2% and 40.4%, active 43.8%, and45.5%, and very active 16.3% and 9.0% for boy and girl, respectively. The highest and significant correlation coefficient between activity coefficient and time spent on activities shown were 0.339 in commute activity for boys, and 0.466 in leisure for girls. The sensitivity of the sedentary conformation by commute hour for boys was 0.79, and that of very active was 0.56. The sensitivity of the sedentary conformation by leisure hour for girls was 0.67, and that of very active was 0.63. The sensitivity of low active and active by 7 different types of activity was quite low, 0.04~0.37. The exact agreement of activity level conformed by easy way developed was 30.8% and 33.7%, for boys and girls, respectively. More accurate way to identify 4 categories activity level needs to be developed, especially sensitive to conformation of low active and active levels.

• 대한감각통합치료학회지
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• 제20권2호
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• pp.11-21
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• 2022

목적 : 본 연구의 목적은 국내에서 개발된 아동감각처리척도(Sensory Processing Scale-Children; SPS-C)의 안정성 확립을 위해 감각처리에 어려움을 가진 만 3~5세 아동의 보호자를 대상으로 검사-재검사 신뢰도와 검사자간 신뢰도를 검증하는 것이다. 연구방법 : 본 연구의 대상자는 감각처리에 어려움을 가진 3~5세 아동 70명이었다. 검사-재검사 신뢰도 검증은 감각처리에 어려움을 가진 아동의 주 양육자 20명이 대상이었다. 초기평가 후 7~14일 내로 재평가를 실시하였고, 두 시점 간 관련성은 피어슨 상관계수를, 일치도는 급내상관계수를 사용하였다. 검사자 간 신뢰도 검증은 감각처리에 어려움을 가진 아동의 주 양육자, 부 양육자 각각 18명을 대상으로 하였다. 두 검사자 간의 일치도 확인은 급내상관계수를 사용하였다. 결과 : 검사-재검사 신뢰도는 피어슨 상관계수 r=.914, 급내상관계수 ICC=.939로 높은 수준의 관련성과 일치도를 나타냈다. 검사자간 신뢰도는 급내상관계수 ICC=.727로 좋은 일치도를 나타냈으나 촉각 영역(ICC=.455)과 고유감각 영역(ICC=.439)은 통계적으로 유의하지 않았지만, 보통의 일치도를 보였다. 결론 : 본 연구를 통해 아동감각처리척도(SPS-C)는 검사-재검사 신뢰도와 검사자간 신뢰도가 검증되어 안정성 있는 평가도구임을 확인하였으며, 추후 임상적 사용을 위한 표준화 연구에 도움을 제공할 수 있을 것이다.

• Computers and Concrete
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• 제7권5호
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• pp.421-435
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• 2010

This paper utilizes the modified Davis model and the mode coupling theory, as parts of the electrolyte solution theory, to investigate the diffusivity of the ion in concrete. Firstly, a computational model of the ion diffusion coefficient, which is associated with ion species, pore solution concentration, concrete mix parameters including water-cement ratio and cement volume fraction, and microstructure parameters such as the porosity and tortuosity, is proposed in the saturated concrete. Secondly, the experiments, on which the chloride diffusion coefficient is measured by the rapid chloride penetration test, have been carried out to investigate the validity of the proposed model. The results indicate that the chloride diffusion coefficient obtained by the proposed model is in agreement with the experimental result. Finally, numerical simulation has been completed to investigate the effects of the porosity, tortuosity, water-cement ratio, cement volume fraction and ion concentration in the pore solution on the ion diffusion coefficients. The results show that the ion diffusion coefficient in concrete increases with the porosity, water-cement ratio and cement volume fraction, while we see a decrease with the increasing of tortuosity. Meanwhile, the ion concentration produces more obvious effects on the diffusivity itself, but has almost no effects on the other ions.

• 한국생활과학회지
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• 제15권3호
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• pp.439-447
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• 2006

The purpose of this study is to explore the accuracy and reliability of subjective evaluation instruments in evaluating sensibility of similar fabrics, Kendall's coefficient of concordance W (agreement among subjects) and Spearman rank correlation coefficient (reproducibility after 1 week) were used to evaluate which one is more efficient. Eight kinds of linen-like silk fabrics finished with polyurethane resin were used, Subjective evaluation instruments such as rating scale method, contrasting method against a control, rank ordering method, paired comparison and Quad analysis were used, 'Stiffness and Pliability' and 'Preference of summer fabric' were estimated, From the result of subjective stiffness and pliability, which are effective on objective properties of fabric, the rating scale method in Kendall's coefficient of concordance W and Quad analysis in Spearman rank correlation coefficient were given the highest score, From the result of subjective preference of summer fabric, which are effective on individual sensibility, contrasting method against a control in Kendall's coefficient of concordance W and Quad analysis in Spearman rank correlation coefficient revealed the highest score, Regarding the accuracy, reliability and efficiency, Quad analysis was an efficient method for subjective evaluation of linen-like silk fabrics.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.852-856
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• 2011

The lithium ion diffusion coefficients of bare, carbon-coated and Cr-doped $LiFePO_4$ were obtained by fitting the discharge curves of each half cell with Li metal anode. Diffusion losses at discharge curves were acquired with experiment data and fitted to equations. Theoretically fitted equations showed good agreement with experimental results. Moreover, theoretical equations are able to predict lithium diffusion coefficient and discharge curves at various discharge rates. The obtained diffusion coefficients were similar to the true diffusion coefficient of phase transformation electrodes. Lithium ion diffusion is one of main factors that determine voltage drop in a half cell with $LiFePO_4$ cathode and Li metal anode. The high diffusion coefficient of carbon-coated and Cr-doped $LiFePO_4$ resulted in better performance at the discharge process. The performance at high discharge rate was improved much as diffusion coefficient increased.

• 대한기계학회논문집
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• 제13권3호
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• pp.424-432
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• 1989

본 연구에서는 정적절삭실험으로 결정될수 있는 절삭변수로 표현되는 동적 절삭력을 해석적으로 구한다. 이 모델은 3차원 절삭형태에도 적용될 수 있는 특성을 갖는다. 새로이 제안된 절삭 과정의 모델은 동적절삭상태에서 절삭력 합력의 변화를 고려한 절삭기구를 통해 이루어지며, 해석적으로 한계절삭폭을 구한다. 실험적 규명 은 채터진동이 발생하지 않는 한계절삭 공작물에 비해 공구의 강성이 상대적으로 적은 보링(boring)작업에서 발생하는 것을 대상으로 하였다.

• 대한한방내과학회지
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• 제33권1호
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• pp.1-13
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• 2012

Background : In oriental medicine, the status of the tongue is an important indicator to diagnose the condition of one's health, such as physiological and the clinicopathological changes of internal organs. A tongue diagnosis is not only convenient but also non-invasive, and therefore widely used in Oriental medicine. However, the tongue diagnosis is greatly affected by examination circumstances, patient's posture, and doctor's diagnosis criteria. Objectives : This study was designed to assure the necessity for standardization of tongue diagnosis based on diagnostic criteria of tongue coating thickness (TCT). Methods : Thirty tongue photographs were acquired and analyzed by digital tongue diagnosis system (DTDS) which measured the percentage of TCT on the tongue surface. Fifteen oriental medical doctors evaluated TCT in 30 photographs. Afterward, the 15 assessors were trained for diagnostic criteria of TCT and evaluated the photographs again. The intraclass correlation coefficient (ICC) was used to obtain the agreement rate among the 15 assessors and the agreement rate between assessors' TCT scores and DTDS values. Results : The agreement rate among the 15 assessors after training was higher than before training. The agreement rate between assessors' TCT scores and DTDS values after training was also higher than before training. Furthermore, the difference of the agreement rate between before and after training was significant (p<0.05). Conclusions : The standardization of diagnostic criteria of TCT increased the agreement rate among the assessors and the agreement rate between assessors' TCT scores and DTDS values. Therefore, the standardization of diagnostic criteria is expected to contribute to the objectification and quantification of the tongue diagnosis system.