• Annual Conference of KIPS
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• 2024.05a
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• pp.440-443
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• 2024

한의학의 증상을 파악하는 한의 변증 진단에서 혀의 형태와 색상을 파악하는 것에서 설질과 설태의 색상을 파악하는 것이 핵심이다. 혀 촬영 장치로 촬영하더라도 조명의 빛 종류와 빛 강도, 위치에 따라 컬러가 변환됨에 따라 혀 취득장치의 컬러교정이 필요하다. 컬러교정을 하지만, 오버피팅, 측정 오류와 노이즈 또는 색상 공간의 불균형으로 컬러의 왜곡이 발생할 수 있다. 이 연구에서는 24개의 patch 중에서 오류를 최소화할 수 있는 patch를 선정하는 최적화의 방법을 제시하려 하였다. 24개 patch 중 몇 개의 선택한 patch의 평균값을 구하여, 기준 값으로 변환시키는 변환 행렬을 구하고, 교정 값을 구하고, 교정된 24 patch 값의 평균과 기준 값과의 오차를 구하여 최소가 되는 변환 행렬을 구하였다. 이 방법은 컬러 챠트의 개수를 줄여 장치의 부피를 줄이는데 활용될 수 있다. 또한 이 방법은 외부의 빛이 차단된 촬영장치에서 활용되었지만, 조명조건이 안정된 개방된 공간에서도 스마트폰을 이용하여 촬영하는데 활용 가능할 것으로 예상된다.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.9-14
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• 2004

이 논문에서는 다중 프로브 교정 시 발생하는 오차를 측정하여 보정함으로써 측정 정밀도를 향상시킬 수 있는 프로그램을 개발에 대하여 연구하였다. 교정 시와 동일한 조건으로 기준구를 측정하여 오차를 산출한 다음 프로브 파라미터가 기록된 시스템 파일을 수정함으로써 교정 오차를 보정하는 프로그램을 개발하였다. 실험 결과 이론값과 실제값의 차가 CMM 분해능의 2배 이내임을 확인하였으며 프로그램은 CMM 사용자가 직접 작성 및 편집 가능하도록 DMIS 언어를 사용하였다.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.1
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• pp.65-74
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• 2018

The aim of this study was to obtain the traceability of the software used to analyze lateral cephalometry and to calculate the uncertainty of the measurements. Furthermore, this study aimed to provide a basis for obtaining standard references for measurement values for orthodontic treatment in children. Cephalometric data were collected from 100 children diagnosed with class I malocclusion between the ages 6 to 13 years who visited the pediatric dentist at Seoul National University Dental Hospital. To ensure traceability, a phantom device was created. Correction values were calculated by measuring the length and angle of the phantom device using the software. Type A uncertainty was calculated by obtaining the standard deviation of cephalometric measurements of 100 persons and the standard error of repeated measurements. Determination of the type B uncertainty was induced by minimum resolution and the position of the head. Using these, the combined standard uncertainty was obtained and the expanded uncertainty was calculated. The results of this study confirm that the currently used software has high accuracy and reliability. Furthermore, the uncertainty of orthodontic measurements in Korean children aged 6 to 13 years was calculated, and distribution range for class I malocclusion with 95% confidence interval was suggested.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.98-106
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• 2016

Measurements of the elastic modulus and hardness using a nano indentation machine rely on the equation for the fitted contact area, which is valid for only sink-in materials. For most soft engineering materials that involve pile-up behavior rather than sink-in, the contact area equation underestimates the contact area and thus overestimates the elastic modulus and hardness. This study proposes a correction method to amend erroneous hardness measurements in pile-up situations. The method is a supplemental derivation to the original hardness measurement with the known value of the elastic modulus. The method was examined for soft engineering metals, Al 6061 T6 and C 12200, via tensile tests, nano indentation tests, impression observations, and finite element analysis. The proposed technique shows reasonable agreement with the analytical results accounting for strain gradient plasticity from a previous study.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.28 no.1
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• pp.41-50
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• 2023

Dissolved oxygen sensors have characteristics in which data drift occurs over time. Therefore, in-situ calibration of the dissolved oxygen sensor is essential to accurately measure the concentration of dissolved oxygen in seawater. In order to provide a method for in-situ calibration, appropriate number of samples for calibration, and laboratory calibration interval of the dissolved oxygen sensor, the dissolved oxygen sensor values were compared with the measured values by titration on a total of 133 samples from three different cruises in the Indian Ocean, Pacific Ocean, and East Sea over a period of about one year. As a result, it is preferable to calibrate the sensor value using the correlation of a straight line obtained by directly comparing the final concentration value given by the sensor and the measured value. For the accurate calibration, at least 30 samples must be used to enable in-situ calibration within an accuracy range of about 1%. In addition, it is recommended that a laboratory calibration should perform within 1 year for the membrane type dissolved oxygen sensor for CTD to achieve a performance of 70% or more.

• Annual Conference on Human and Language Technology
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• 1993.10a
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• pp.317-328
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• 1993

본 논문은 신경망과 퍼지 이론을 결합한 한국어 철자 교정기 KSCNN(Korean Spelling Corrector using Neural Network)에 대하여 기술한다. KSCNN은 퍼셉트론(perceptron) 학습을 이용한 연상 메모리(associative memory)로 구성되며 자판 배열 특성을 고려한 퍼지 멤버쉽 함수에 의해 신경망의 입력값을 정한다. 본 철자 교정기의 장점은 인지적인 방법으로 철자를 교정하기 때문에 기존의 VA나 BNA와는 달리 오류의 종류에 영향을 받지 않으며 교정된 철자나 후보자들에 대한 견인값(attraction value)을 측정하여 시스템의 신뢰도를 높일 수 있다는 데 있다. 또한, 본 논문은 실험을 통해서 퍼지 멤버쉽 함수에 의한 입력 노드의 활성화가 자판 배열특성을 고려할 수 있기 때문에 시스템의 성능을 향상시킨다는 사실을 보여준다.

• The Journal of the Acoustical Society of Korea
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• v.22 no.6
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• pp.463-471
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• 2003

The results of the APMP (Asia Pacific Metrology Programme) regional intercomparison of acoustic calibrators were reviewed and analyzed. The artefacts used in intercomparison are a sound level calibrator and a pistonphone. The microphones used to measure the output pressure level are 1" and 1/2" standard microphones (LS1P, LS2P) as well as 1" and 1/2" reference microphones (WS1P/F, WS2P/F). The results obtained using standard microphones are satisfactory, but those obtained by the reference microphones, even though E/sub n/ values are within ±1.0, showed great deviations. Such results had come from the inaccurate calibration of reference microphones. By using the correct calibration results which were obtained by the recently established international standards, the new results were very similar to those of the foreign standard institutes.

• Journal of Sensor Science and Technology
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• v.12 no.6
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• pp.258-264
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• 2003

The present paper studies how to calibrate hydrometer using image process. The method aligns particular scales of hydrometer selected for calibrating the hydrometer with the horizontal plane of the reference liquid automatically without man's operation. Major parts composing the system are CCD camera, frame grabber, stepping motor and image process program. The image process program is composed of a part that locates the meniscus and aligns it with a scale and a part that controls the step motor. To verify the performance of the developed method, this study compares the meniscus and scale observed directly with the naked eye with the result of calibration by the manual calibration method. The differences between the corrections were less than $0.004\;kg/m^3$ with uncertainty of $0.06\;kg/m^3$. These showed that the calibration results of the developed hydrometer calibration using image process nearly equal to manual method.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.4
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• pp.367-374
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• 2004

In order for the measurement results of an electro-optical distance meter(EDM), which is widely used in surveying, to be reliable, an EDM should be calibrated. For the calibration of an EDM, we have settled a traceability chain, which connects the EDM under calibration to the definition of metre. The chain starts from the iodine stabilized He-Ne laser which realizes the definition of metre, and then connected to a stabilized laser interferometer, a standard EDM, and finally to the EDM under calibration through the baseline. We achieved the expanded calibration uncertainties of the scale and length measurement of an EDM being evaluated to be 6$\times$10$^{-6}$ and 0.2 mm, respectively. Two different calibration methods, and their results are compared.

• Journal of Sensor Science and Technology
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• v.4 no.1
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• pp.43-50
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• 1995

We measured the traceability error for nine high temperature calibration service centers including KRISS through the round-robin test. In this test the type S thermocouple, which used as a calibration standard thermometer commonly, was accommodated as a test thermocouple. Intercomparison data of three institutions were coincident with KRISS's data within ${\pm}0.5^{\circ}C$, which was the calibration uncertainty of the type S thermocouple, but the remaining six institution's data were deviated from the assigned uncertainty level. Deviation of the intercomparison data increased gradually according to the increase of the test temperature. and the maximum difference was so large as about $2.0^{\circ}C$ at the highest test temperature, gold point. In this study we found the traceability error of high temperature calibration service center for a high temperature standard was within $2.0^{\circ}C$.