• 대한인간공학회지
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• 제28권4호
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• pp.117-124
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• 2009

To inspect the quality of data collected from a large-scale body measurement and investigation project, it is necessary to establish a proper data editing process. The three-dimensional body measurement may have measuring errors caused from measurer's proficiency or changes in the subject's posture. And it may also have errors caused in the process of algorithm expressing the information obtained from the three-dimensional scanner into numerical values, and in the course of data-processing dealing with numerous data for individuals. When those errors are found, the quality of the measured data is deteriorated, and they consequently reduce the quality of statistics which was conducted on the basis of it. Therefore this study intends to suggest a new way to improve the quality of the data collected from the three-dimensional body measurement by proposing a working procedure identifying data errors and correcting them from the whole data processing procedure-collecting, processing, and analyzing- of the 2004 Size Korea Three-dimensional Body Measurement Project. This study was carried out into three stages: Firstly, we detected erroneous data by examining of logical relations among variables under each edit rule. Secondly, we detected suspicious data through independent examination of individual variable value by sex and age. Finally, we examined scatter-plot matrix of many variables to consider the relationships among them. This simple graphical tool helps us to find out whether some suspicious data exist in the data set or not. As a result of this study, we detected some erroneous data included in the raw data. We figured out that the main errors are not because of the system errors that the three-dimensional body measurement system has but because of the subject's original three-dimensional shape data. Therefore by correcting some erroneous data, we have enhanced data quality.

• Agricultural and Biosystems Engineering
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• 제4권1호
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• pp.16-21
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• 2003

In the agricultural field, a machine vision system has been widely used to automate most inspection processes especially in quality grading. Though machine vision system was very effective in quantifying geometrical quality factors, it had a deficiency in quantifying color information. This study was conducted to evaluate color of beef using machine vision system. Though measuring color of a beef using machine vision system had an advantage of covering whole lean tissue area at a time compared to a colorimeter, it revealed the problem of sensitivity depending on the system components such as types of camera, lighting conditions, and so on. The effect of color balancing control of a camera was investigated and multi-layer BP neural network based color calibration process was developed. Color calibration network model was trained using reference color patches and showed the high correlation with L*a*b* coordinates of a colorimeter. The proposed calibration process showed the successful adaptability to various measurement environments such as different types of cameras and light sources. Compared results with the proposed calibration process and MLR based calibration were also presented. Color calibration network was also successfully applied to measure the color of the beef. However, it was suggested that reflectance properties of reference materials for calibration and test materials should be considered to achieve more accurate color measurement.

• 한국물환경학회지
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• 제22권2호
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• pp.230-237
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• 2006

The operational parameters and control strategies of a tertiary wastewater treatment process a biological filtration system were investigated. The biological filtration system consisted of a nitrification filter (Fiter 1) and a polishing filter with anoxic and aerobic parts (Filter 2). SS, T-C-BOD, and T-N in effluent were kept stable at less than 3, 5 mg/L, and 5 mgN/L, respectively, under a HRT in Filter (filter-bed) of 0.37~2.3 h. T-N at the outlet of Filter 2 were about 1~5 mgN/L under the condition of LV of 50~202 m/d. Methanol addition was controlled based on the COD/N ratio or McCarty's equation. Constant COD/N ratio control results in excess addition under large diurnal fluctuation of $NOx^--N$, and McCarty's equation can be used to add appropriate amount of methanol. Control of methanol addition by on-line nitrate measurement, control of aeration by on-line DO measurement, and control of backwashing by head loss measurement are successfully operated. These results proved that this process prove the easy-maintenance and cost-effectively treatment is attainable.

• Design & Manufacturing
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• 제17권1호
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• pp.1-5
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• 2023

In multi-material injection molding, since two or more materials with different process conditions are used, it is essential to maximize process efficiency by operating the cooling or heating system to a minimum. In this study, Liquid silicone rubber (LSR) that can be cured at a low temperature suitable for the multi-material injection molding was selected and the cure behavior according to the process conditions was analyzed through differential scanning calorimetry (DSC). Dynamic measurement results of DSC with different heating rate were obtained, and through this, the total heat of reaction when the LSR was completely cured was calculated. Isothermal measurement results of DSC were derived for 60 minutes at each temperature from 80 ℃ to 110 ℃ at 10 ℃ intervals, and the final degree of cure at each temperature was calculated based on the total heat of reaction identified from the Dynamic DSC measurement results. As the result, it was found that when the temperature is lowered, the curing start time and the time required for the curing reaction increase, but at a temperature of 90 ℃ or higher, LSR can secure a degree of cure of 80% or more. However, at 80 ℃., it was found that not only had a relatively low degree of curing of about 60%, but also significantly increased the curing start time. In addition, in the case of 110 ℃, the parameters were derived from experimental result using the Kamal kinetic model.

• 디지털융복합연구
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• 제16권8호
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• pp.381-391
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• 2018

이 연구는 스포츠윤리교육 프로그램에 대한 교육만족도 측정도구를 개발하고 그 타당성을 검증하는 데 목적이 있다. 연구의 목적을 달성하기 위하여 연구절차는 다음과 같이 3단계로 이루어졌다. 1단계에서는 스포츠윤리교육 프로그램과 관련된 선행연구를 분석하고, 개방형 질문지를 통해 얻어진 응답 결과를 토대로 예비문항을 구성하였다. 2단계는 예비조사단계로서 1단계에서 진행된 측정도구의 탐색적 요인분석과 확인적 요인분석을 통해 구인타당성을 확보하였다. 3단계는 본 조사 단계로서 차이 검증을 통해 측정도구의 외적타당도를 확보하였으며, 이를 통해 도출된 내용을 중심으로 교육만족도측정을 위한 문항을 구성하였다. 그 결과 교육내용 6문항, 강사역량 5문항, 교육효과 6문항, 총 3개 영역 17개 문항으로 스포츠윤리교육 프로그램의 교육만족도 측정도구가 개발되었다. 이 연구는 실효성 있는 스포츠윤리교육 프로그램 개발을 위한 기초자료로 활용될 수 있으며, 이를 통해 윤리적인 소양을 지닌 스포츠선수로 성장할 수 있는 기반이 마련됨으로써 궁극적으로 스포츠계의 변화와 발전에 기여할 수 있기를 기대한다.

• 한국전자통신학회논문지
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• 제16권1호
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• pp.117-124
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• 2021

성장 장애 중 저신장증은 빠른 진단과 치료를 통해 호전시킬 수 있는데 이를 위해서는 저신장증의 조기발견이 중요하다. 저신장증 조기발견 및 아이의 성장 과정 확인을 위해 꾸준히 키를 측정하는 것이 권장되지만 기존의 키 측정방법들에는 시간적·공간적 한계와 비용 발생, 기록유지의 어려움 등의 문제들이 존재한다. 그래서 본 논문에서는 사람들의 접근성이 높은 매체인 스마트폰을 이용하는 '컴퓨터 비전을 이용한 이미지 기반 아이 키 측정 애플리케이션 개발' 방법을 제안하였다. 스마트폰의 카메라를 통해 촬영된 이미지에서 컴퓨터 비전 라이브러리인 OpenCV의 알고리즘들을 이용하여 아이의 키를 측정하고, 그렇게 측정된 키는 성별·나이별 표준 신장과의 비교 그래프, 날짜별 리스트를 통해 화면에 출력함으로써 아이의 성장 과정 확인이 가능하도록 하였다. 이 제안된 방법을 통해 시간적·공간적 제약 및 비용 발생 없이 언제 어디서든 키를 측정할 수 있을 것이라 기대되고, 꾸준한 키 측정과 성장 과정 확인을 통한 저신장증 및 성장 장애의 조기발견에 도움이 될 것이라 기대된다.

• International Journal of Precision Engineering and Manufacturing
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• 제2권2호
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• pp.73-80
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• 2001

The objective of this research is to develop a measurement error model for sculptured surface in On-Machine Measurement(OMM) process based on a closed-loop configuration. The geometric error model of each axis of a vertical CNC machining center is derived using a 4$\times$4 homogeneous transformation matrix. The ideal locations of a touch-type probe for the sculptured surface measurement are calculated from the parametric surface representation and X-, Y- directional geometric errors of the machine. Also the actual coordinates of the probe are calculated by considering the pre-travel variation of a probe and Z-directional geometric errors. Then, the step-by-sep measurement error analysis method is suggested based on a closed-loop configuration of the machining center including workpiece and probe errors. The simulation study shows the simplicity and effectiveness of the proposed error modeling strategy.

• 제어로봇시스템학회논문지
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• 제9권6호
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• pp.473-477
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• 2003

An immersion-type on-line refractometer useful for the in-situ measurement of chemical composition and temperature is developed, and its performance is examined by applying the refractometer to known alcohol solution having concentrations between 0 vol. % and 25 vol. %. Because refractive index and temperature are measured simultaneously, it is possible to compensate the effect of temperature for fast and direct measurement. The outcome of composition measurement for the different concentrations of alcohol solution indicates that the device is suitable for the chemical composition measurement by yielding stable and reproducible reading.

• 한국지반공학회논문집
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• 제40권3호
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• pp.85-91
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• 2024

시멘트계열 재료를 이용한 지반보강 시 처리지반의 안정적 이용을 위하여 해당 재료의 양생과정 평가가 요구된다. 본 연구에서는 전자기적 물성 기반 시멘트 그라우트의 양생과정 평가를 위하여 시계열반사계(TDR) 측정시스템을 적용하였다. 시멘트 그라우트의 높은 전도성으로 인한 프로브 내 전극간 전기적 연결을 방지하기 위하여 코팅 프로브를 제작하였으며, 코팅 프로브로부터 실제 비유전율 평가를 위한 보정실험이 수행되었다. 코팅 프로브가 적용된 TDR 측정시스템으로부터 시멘트 그라우트의 양생과정을 평가하고자 지연제가 첨가된 물시멘트비 45%의 초속경시멘트 그라우트가 준비되었으며, 몰드 내 타설 직후 예비측정 및 배합 후 3~288시간 경과 시점에서 TDR 신호를 수집, 비유전율을 평가하였다. 실험 결과, 타설 직후의 시멘트 그라우트는 100 이상의 높은 비유전율 상태를 나타내었으나 양생시간이 경과함에 따라 급격한 감소 경향을 보였으며, 양생 144시간 시점부터의 비유전율은 약 13.8로 수렴하여 해당 시간을 양생 완료시점으로 판단하였다. 본 연구에서 이용된 코팅 프로브 TDR 측정시스템은 전도성 재료에 대한 적용성과 더불어 전자기적 물성 기반 시멘트계열 지반보강재 양생과정 모니터링에 활용될 수 있을 것이라 기대된다.

• 한국기계가공학회지
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• 제10권5호
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• pp.26-30
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• 2011

Currently, many researches are carried out about tilting index table, which is one of the main component of 5-axis machine tool. The performance of the tilting index table is associated the rotational accuracy which is very important factor for high precision machining because it have an effect on machining error. In this paper, a tilting index table is developed, and the rotational accuracy of the tilting index table using a laser measurement equipment is measured. In addition, a correction value is obtained from the measured value through compensation, and the correction value is used to improve the accuracy of the table. Comparative analysis is carried out for the accuracy of the table before and after compensation. This paper can be used by a reference for performance and reliability advancement of tilting index table.