• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.283-288
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• 2004

The measurement of ultra low aspect ratio fluid film thickness is very crucial technique both for the verification of lubrication media characteristics and for the clearance design in many precision components such as MEMS, precision bearings and other slideways. Many technologies are applied to the measurement of ultra low aspect ratio fluid film thickness (i.e. elastohydrodynamic lubrication film thickness). In particular, in-situ optical interferometric method has many advantages in making the actual contact behaviors realized with the experimental apparatus. This measurement method also does the monitoring of the surface defects and fractures happening during the contact behavior, which are delicately influenced by the surface conditions such as load, velocity, lubricant media as well as surface roughness. Careful selection of incident lights greatly enhances the fringe resolutions up to $\~1.0$ nanometer scale with digital image processing technology. In this work, it is found that coaxial aligning trichromatic incident light filtering system developed by the author can provide much finer resolution of ultra low aspect ratio fluid film thickness than monochromatic or dichromatic incident lights, because it has much more spectrums of color components to be discriminated according the variations of film thickness. For the measured interferometric images of ultra low aspect ratio fluid film thickness it is shown how the film thickness is finely digitalized and measured in nanometer scale with digital image processing technology and space layer method. The developed measurement system can make it possible to visualize the contact deformations and possible fractures of contacting surface under the repeated loading condition.

• 대한물리치료과학회지
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• 제19권1호
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• pp.17-25
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• 2012

Purpose : The aim of this study was from data collection to item development in the first study before developing a valid and reliable instrument reflecting Korean's own language expression and culture. Methods : The fist survey was 140 osteoarthritis(OA) patients in 2 Cites was studied from November to December 2009. Open-ended questionnaire was decided 39 items from the first open survey. Questionnaire on the Korean Osteoarthritis Impact Measurement Scale(KAIMS) was recruited 2 professors and 5 physical therapists. Second survey was applied to 133 OA patients. Results : OA patients's average age${\pm}$standard deviation was $66.08{\pm}11.10$ years. The internal consistency reliability of 3 items. As estimated by Cronbach's alpha coefficient(${\alpha}$), was high(range, 0.86~0.96). 0.43~0.91 ${\alpha}$ coefficient for the internal consistency reliability of item-each scale was also high. However, item-discriminant validity on 3 items was low(${\alpha}$, 0.92~0.97). The construct validity by factor analysis was a little low. Conclusion : This study revealed that we confirmed a generation for 39 items on KAIMS reflecting Korean's own language expression and culture. Also, those of reliability were a little high. And, we will have to study the last instrument development (3rd study) by more subjects in the future.

• Child Health Nursing Research
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• 제24권4호
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• pp.484-495
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• 2018

Purpose: This study was conducted to develop a scale for measuring aggression in adolescents, based on Ajzen's Theory of Planned Behavior (TPB). Methods: The participants were 38 adolescents in an in-depth study conducted to develop items for indirect measurement, 13 adolescents in a pre-test, and 289 adolescents in the present survey. The collected data were analyzed using content validity, the correlation coefficient, exploratory factor analysis, confirmatory factor analysis, reliability, and the Cronbach's ${\alpha}$. Results: In this study, the most important variable related to aggression was found to be aggression intention. This study included 4 factors of direct measurement and 6 factors of indirect measurement; therefore, 41 questions were developed. Increased levels of aggression were associated with higher scores for attitudes of aggression, subjective norms, perceived behavioral control, and aggression intention. Conclusion: We found that the questionnaire used in this study was valid and reliable as a measurement scale to explain aggression in adolescents based on TPB. Aggression intention should be included in aggression prevention programs because it was linked to aggressive behavior.

• 제어로봇시스템학회논문지
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• 제8권8호
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• pp.625-632
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• 2002

We propose an outsole measurement/inspection system to improve the quality of the shoe product. It uses the Divide-and-Conquer technique to measure the length of shoes'outsole. First, it detects edge positions of outsole's toe and heel from each image frame using an unique scale block we defined and calculates the outsole's length as the distance of two edge positions. Then it compensates the total length of outsole using the side image of outsole. Next, it classifies the outsole as inferior goods if the measurement error is bigger than 5.8mm. As a result of testing with the various kinds of outsoles, it was shown that the 95% accuracy was acquired within 1mm allowable error range. In conclusion, the proposed inspection system is effective and useful in the measurement/inspection process of shoe product and any material object as well.

• 한국정밀공학회지
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• 제32권6호
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• pp.543-551
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• 2015

In this study, a novel method for dimension measurement of large-scale moving objects using stereo camera with 2-degree of freedom (2-DOF) mechanism is presented. The proposed method utilizes both the advantages of stereo vision technique and the enlarged visibility range of camera due to 2-DOF rotary mechanism in measuring large-scale moving objects. The measurement system employs a stereo camera combined with a 2-DOF rotary mechanism that allows capturing separate corners of the measured object. The measuring algorithm consists of two main stages. First, three-dimensional (3-D) positions of the corners of the measured object are determined based on stereo vision algorithms. Then, using the rotary angles of the 2-DOF mechanism the dimensions of the measured object are calculated via coordinate transformation. The proposed system can measure the dimensions of moving objects with relatively slow and steady speed. We showed that the proposed system guarantees high measuring accuracy with some experiments.

• Wind and Structures
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• 제29권6호
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• pp.471-488
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• 2019

Wind pressure is a critical argument for the wind-resistant design of structures. The attempt, however, to explore the wind pressure field on buildings still encounters challenges though a large body of researches utilizing wind tunnel tests and wind field simulations were carried out, due to the difficulty in logical treatments on the scale effect and the modeling error. The full-scale measurement has not yet received sufficient attention. By performing a field measurement, the present paper systematically addresses wind pressures on the rectangular attic of a double-tower building. The spatial and temporal correlations among wind speed and wind pressures at measured points are discussed. In order to better understand the wind pressure distribution on the attic facades and its relationship against the approaching flow, a full-scale CFD simulation on the similar rectangular attic is conducted as well. Comparative studies between wind pressure coefficients and those provided in wind-load codes are carried out. It is revealed that in the case of wind attack angle being zero, the wind pressure coefficient of the cross-wind facades exposes remarkable variations along both horizontal and vertical directions; while the wind pressure coefficient of the windward facade remains stable along horizontal direction but exposes remarkable variations along vertical direction. The pattern of wind pressure coefficients, however, is not properly described in the existing wind-load codes.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2007년도 공동학술대회 논문집
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• pp.297-302
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• 2007

Recently, electrical resistivity survey is used in the various fields and applied to urban area with many electrical noises. Therefor it's necessary to observe the electrical noise effect of the geological structure. The physical scale modeling was conducted for measuring the electric noise effect of the two geological models at various distances, depths and diameters of the electric noise objects. The results are as following. 1. When conductive noise object was vertical to the strike of geological structure and moved to the strike direction, the effect of conductive noise object at various separated distances to the measurement line was disappeared at a half distance measurement line length regardless of electrode arrays. 2. When conductive noise object was vertical to the strike of geological structure and moved to the strike direction, the effect of conductive noise object at various depths was disappeared at 4unit apart from the measurement line regardless of electrode arrays. 3. When conductive noise object was vertical to the strike of geological structure and moved to the strike direction, the effect of conductive noise object at various diameters was disappeared at 4unit apart from the measurement line regardless of electrode arrays.

• 동아시아경상학회지
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• 제3권3호
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• pp.1-13
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• 2015

The purposes of this research are to develop a measurement of Islamic religiosity and applying these measurements to examine the relationship between religiosity and selection of the Islamic bank. Literature searches and in -depth interviews are used to obtain the statement item to build measurement. Furthermore, result of the religiosity measurement will be used to study the relationship between religiosity and the selection of the Islamic bank. Population of the study is Muslim who has bank(s) account. A total 375 questionnaires were distributed to the three groups of bank customers (125 respondents in each group). This res earch has successfully developed a measurement of religiosity, which is called Islamic Religiosity Scale (IRS). On the one hand, the study indicate that religiosity plays a significant role on the decision of customers to choose Islamic banks, because the degree of religiosity of Islamic bank customers is higher than conventional bank customers. Nevertheless, on other hand, this study also revealed that religiosity is not the only factor that influences customers to selecting the Islamic banks, because the degree of religiosity of Islamic bank customers do not differ significantly with customers who hold accounts in both bank.

• 한국콘텐츠학회논문지
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• 제17권2호
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• pp.137-148
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• 2017

본 연구의 목적은 유아의 자아탄력성을 측정할 수 있는 척도를 개발하여 타당도와 신뢰도를 검증하는 것이다. 연구대상은 광주광역시와 전남지역에 소재한 유아교육기관에 재원하고 있는 만3, 4, 5세 유아 289명이었다. 수집된 자료는 SPSS 18.0, AMOS 18.0 프로그램을 사용하여 요인분석과 신뢰도 분석을 하였다. 탐색적 요인분석 결과 '주의집중', '정서조절', '자기효능감', '공감', '또래관계'의 5개 요인의 26문항이 구성되었다. 확인적 요인분석 결과 모델 적합도 지수는 RMSEA=.059, NNFI=.901와 CFI=.913로 나타났고, 공인타당도 검증을 위해 KPRC의 자아탄력성 척도와 상관관계를 확인한 결과 두 척도 간에는 높은 상관을 보이는 것으로 나타났다. 또한 내적일관성 지수인 Chronbach ${\alpha}$를 분석한 결과 신뢰도도 양호한 것으로 나타났다. 따라서 본 연구에서 개발된 척도는 유아의 자아탄력성을 측정하기 위한 척도로서 신뢰도와 타당도가 적합한 것으로 나타났다.

• 한국통신학회논문지
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• 제29권8C호
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• pp.1104-1112
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• 2004

본 논문에서는 레이저와 고속 CCD 카메라를 이용하여 대형 구조물의 3차원 거동 계측을 위해 진동 주파수 계측 방식을 확립하였다. 구조물에 부착한 대상판에 변동(fluctuation)이 작은 다이오드 레이저를 투사하고, 고속 CCD 카메라로 촬영한 영상에 고정도 상대측정 알고리즘을 적용하여 구조물의 변위를 측정하였다. 초당 120 프레임의 고속 카메라를 이용하고 변위에 FFT를 취해 진동주파수를 구한 경우, 0에서 40Hz까지 $\pm$0.5% 이내의 진동주파수의 정확도를 얻을 수 있다. 이를 이용하면 대형 구조물에 대해 보다 저렴하고 간단하게 고유진동수의 측정이 가능하다. 또한 GPS를 이용한 상대측위 기법과의 비교를 통해 레이저를 이용한 변위측정의 정확도를 입증함으로써, 제안한 진동주파수 측정 방법의 신뢰도와 경제성을 검증하였다.