• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2001년도 학술대회논문집
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• pp.119-122
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• 2001

We derived the resolution of the modified triangular interferometer and described the analysis about distance measurement using the one. Also, to demonstrate the feasibility of distance measurement using the modified triangular interferometer, the incoherent hologram of a two-point source with depth and its numerical reconstruction were presented.

• 대한공간정보학회지
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• 제17권1호
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• pp.97-104
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• 2009

지적도근점과 도시기준점은 설치의 목적과 성격은 다르지만 측량방법, 매설 위치 등이 매우 유사하다. 그렇기 때문에 두 기준점을 연계하여 활용할 수 있다면 도근점 망실에 의한 복구비용의 최소화는 물론 배점밀도의 향상을 가져올 수 있을 것이다. 따라서 본 연구에서는 지적도근점을 기초로 도시기준점의 위치정확도를 분석하여 봄으로써 두 기준점을 연계하여 활용할 수 있는 가능성을 제시하고자 하였다. 연구결과는 다음과 같다. 연구대상지역 총 13점의 도시기준점의 위치정확도를 분석하여 본 결과, 각각의 측점에 대한 연결오차의 RMSE가 최소 ${\pm}8cm$에서 최대 ${\pm}11cm$ 오차를 보이는 것으로 나타났다. 이러한 결과는 현행 지적법에서 규정하고 있는 허용오차 범위내의 성과로 지적도근점과 도시기준점을 연계하여 이용할 수 있는 가능성을 확인할 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.73-74
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• 2010

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.969-970
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• 2008

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1994년도 춘계공동학술대회논문집; 창원대학교; 08월 09일 Apr. 1994
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• pp.112-121
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• 1994

Studies on visual fatigues were activated after VDTs were rapidly introduced into the office works in 1980s. Various measurement methods and its measures were developed from those studies. Early studies frequently used simple measures such as near point of accommodation, near point of vergence, and CFF. Current researches focus on dark focus, dark vergence, and VEP which have a good relevance to the visual fatigues. In spite of the merit they also have some limits and disagreements. This survey summarizes the measures, measurement methods and relevant researches. Finally several topics are proposed for the future researches in Korea.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 A
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• pp.378-380
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• 2003

This paper presents the optimal point for measuring harmonic levels in distribution systems. Harmonic should be measure PCC (Point of Common Coupling), where is extended over distribution systems, but some PCCs are limited for economical and technical reason : for this reason, the harmonic measurement for a real distribution system and computer simulation are performed to find the optimal PCC in this paper.

• Advances in biomechanics and applications
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• 제1권4호
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• pp.269-277
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• 2014

In skin-marker based motion analysis, knee translation measurement is highly dependent on a pre-selected reference point (functional center) on each segment determined by the location of anatomical landmarks. However, the placement of skin markers on palpable anatomical landmarks (i.e., femoral epicondyles) has limited reproducibility. Thus, it produces large variances in knee translation measurement among different subjects, as well as across studies. In order improve the repeatability of knee translation measurement, in this study an optimization method was introduced, by which the femoral functional center was numerically determined. At that point the knee anteroposterior translation during the stance phase of walking was minimized. This new method was tested on 30 healthy subjects during walking in gait lab with motion capture system. Using this new method, the impact of skin marker position (at anatomical landmarks) on the knee translation measurement has been minimized. In addition, the ranges of anteroposterior knee translations during stance phase were significantly (p<0.001) smaller than those measured by conventional method which relies on a pre-selected functional center ($11.1{\pm}3.5mm$ vs. $19.9{\pm}5.5mm$). The results of anteroposterior translation using this new method were very close to a previously reported knee translation (12.4 mm) from dual fluoroscopic imaging technique. Moreover, this new method increased the reproducibility of knee translation measurement by 50%.

• 한국의상디자인학회지
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• 제14권1호
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• pp.81-96
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• 2012

The purpose of this study is to provide fundamental information for standardization of 3D body measurement. This research analyzes errors occurring in the process of extracting body size from 3D body scan data. First, as a result of analyzing basic state of the 3D body scanner's calibration, the point number of each section was almost the same, while the right and left as well as the front and back coordinates of the center of gravity are not, showing unstable data. Nevertheless, the latter does not influence on the size of cylinder such as width and circumference. Next, we analyzed point coordinates variations of scan data on a mannequin nude by life casting. The result was great deflection in case of complicated or horizontal sections including the reference point beyond proper distance from centers of four cameras. In case of the mannequin's size, accuracy proves comparatively high in that measurement errors in height, width, depth, and length dimension occurred all within allowable errors, only except chest depth, while there were a lot of measurement errors in a circumference dimension. Secondly, analysis of accuracy of automatic extraction identification program algorithm presented that a semi-automatic measurement program is better than an automatic measurement program. While both of them ate very acute in parts related to crotch, they are not in armpit related parts. Therefore, in extracting of human body size from 3D scan data, what really matters seems to parts related to armpits.

• Environmental Engineering Research
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• 제12권4호
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• pp.176-193
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• 2007

The ability to measure groundwater contaminant flux is increasingly being recognized as crucial in order to prioritize contaminated site cleanups, estimate the efficiency of remediation technologies, measure rates of natural attenuation, and apply proper source terms to model groundwater contaminant transport. Recently, a number of methods have been developed and subsequently applied to measure contaminant mass flux in groundwater in the field. Flux measurement methods can be categorized as either point methods or integral methods. As the name suggests, point methods measure flux at a specific point or points in the subsurface. To increase confidence in the accuracy of the measurement, it is necessary to increase the number of points (and therefore, the cost) of the sampling network. Integral methods avoid this disadvantage by using pumping wells to interrogate large volumes of the subsurface. Unfortunately, integral methods are expensive because they require that large volumes of contaminated water be extracted and managed. Recent work has investigated the development of an integral method that does not require extraction of contaminated water from the subsurface. We begin with a review of the significance and importance of measuring groundwater contaminant mass flux. We then review groundwater contaminant flux measurement methods that are either currently in use or under development. Finally, we conclude with a qualitative comparison of the various flux measurement methods.

• 한국안전학회지
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• 제32권3호
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• pp.41-47
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• 2017

Recent studies have shown that there are various systems which can be used to monitor hazardous area in a debris flow location, but lack of methodological research on the exact location where each instrument should be installed has hindered the success of this systems. The objective of this study is to suggest the measurement system for monitoring debris-flow and propose the effective method to determine location of measurement system. Previously studied, from 1991 to 2015, were referred and the applied ratio of every instrument was investigated. The measurement information was divided into 8 categories including rainfall, debris-flow velocity, displacement, fluid pore pressure, ground vibration, image processing, impact force and peak flow depth. The result of this study revealed that the most applied instruments to be rain gauge and geophone for measuring average rainfall and ground vibration respectively. The Analytic Hierarchical Process (AHP) method was selected to determine installation location of instrument and the weighting factors were estimated through fine content, soil thickness, porosity, shear strength, elastic modulus, hydraulic conductivity and saturation. The soil thickness shows highest weights and the fine content relatively demonstrates lowest weights. The score of each position can be calculated through the weighting factors and the lowest score position can be judged as the weak point. The weak point denotes the easily affecting area and thus, the point is suitable for installing the measurement system. This study suggests a better method for safely managing the debris-flow through a precise location for installing measurement system.