• 한국생산제조학회지
• /
• 제8권4호
• /
• pp.130-135
• /
• 1999

The main scale of linear encoder greatly effects on the precision of displacement measurement. Especially when needing the long range measurement the length of main scale should be increased accordingly. In this paper we propose a linear encoder that uses laser interference pattern as main scale for long range measurement. The linear encoder is similar to Michelson interferometer excepting that the reference mirror is tilted so as to obtain interference fringe pattern and a grating panel is attached on a quadratic photo diodes. Four kinds of grating having phase difference of 0. $\pi$/4, $\pi$/2, 3$\pi$/4 are arranged on the panel. The experimental results show that signals of quadratic photo diode A, B, {{{{ {-}atop {A } }}}} and {{{{ {- } atop {B } }}}} are cosine wavelike and successive signals have phase difference of $\pi$/4 each other. So the proposed method can achieve improved measurement resolution.

• 한국공작기계학회:학술대회논문집
• /
• 한국공작기계학회 1999년도 춘계학술대회 논문집
• /
• pp.170-174
• /
• 1999

The main scale of linear scale greatly affects on the precision of displacement measurement. Especially when needing the long range measurement, the length of main scale should be increased accordingly. In this paper, we propose a linear scale that uses laser interference pattern as main scale for long range measurement. The linear scale is similar to Michelson interferometer excepting that the reference mirror is tilted so as to obtain interference fringe pattern and a grating panel is attached on a quadratic photo diodes. Four kinds of grating having phase differences of 0, $\pi$ /4, $\pi$ /2, 3 $\pi$ /4 are arranged on the panel. The experimental results show that signals of - quadratic photo diode, A, B,$\overline{A}$ and $\overline{B}$ are cosine wavelike and successive signals have phase difference of $\pi$/4 each other. So the proposed method can achieve improved measurement resolution.

• Journal of the Optical Society of Korea
• /
• 제17권5호
• /
• pp.392-398
• /
• 2013

As the essential techniques for the CD (Critical Dimension) measurement of the LCD pattern, there are various modules such as an optics design, auto-focus [1-4], and precise edge detection. Since the operation of image enhancement to improve the CD measurement repeatability, a ring type of the reflected lighting optics is devised. It has a simpler structure than the transmission light optics, but it delivers the same output. The edge detection is the most essential function of the CD measurements. The CD measurement is a vital inspection for LCDs [5-6] and semiconductors [7-8] to improve the production yield rate, there are numbers of techniques to measure the CD. So in this study, a new subpixel algorithm is developed through facet modeling, which complements the previous sub-pixel edge detection algorithm. Currently this CD measurement system is being used in LCD manufacturing systems for repeatability of less than 30 nm.

• 한국정보통신학회논문지
• /
• 제16권12호
• /
• pp.2619-2627
• /
• 2012

전자 부자 흐름 패턴 시스템은 위치 측위 기술과 여러 가지 통신 기술을 이용하여 원격에서 부자의 위치를 모니터링 함으로써 하천의 유량을 예측할 수 있다. 현재 자연하천의 흐름 패턴을 분석하기 위해 여러 형태의 수동 부자들이 사용되고 있다. 수동 부자를 이용한 유량 측정은 유량을 측정하기위해 거리와 시간을 직접 측정한 후 이것을 이용한다. 이러한 방법은 측정방법과 정확한 유량 측정 측면에서 효율적이지 못하다. 이러한 문제를 극복하기 위해 본 연구진은 CDMA, GPS 그리고 2.4GHz기반의 RF모듈을 이용하여 전자부자를 설계 및 구현했다. 그리고 전자부자의 위치정보와 흐름 패턴 정보를 알기 위한 모니터링 시스템을 설계 및 구현하였다. 더불어 배터리로 동작하는 전자부자에서 짧은 life cycle은 전자부자를 이용한 흐름 패턴 시스템에서의 효용성을 떨어뜨린다. 이를 극복하기 위해 전자부자 흐름 패턴 시스템의 전자부자를 위한 전원 절약 기법을 설계하였다.

• 한국의류산업학회지
• /
• 제17권3호
• /
• pp.447-461
• /
• 2015

The purpose of this study is to develop a torso pattern that is highly representative for the proper body shape of women in their thirties. Size data of the women with age of 30 through 39 from the database of Size Korea 2004 were used for the study. In order to develop a master pattern which will be used as the benchmark for grading of research group, 4 existing torso block drafting methods were compared based on the data gathered and the block with the highest evaluation score was utilized as a reference point. For the analysis, data was divided into four types, only the data of 138 subjects which were evaluated at least by four or more experts as valid were used for the study. The major results can be summarized as follow. The women of bust girth of 91cm and height of 160cm which was turned out to be representative type of research group were used as standard measurement for the purpose of reflecting not only curve length of the 3D analysis measurement but also the difference between front and back thickness to the pattern. Dart locations were set based on front and back torso ease, shoulder area revisions, front sagging length 1.5cm and cross section crevice length analysis. According to the experts' appearance evaluation of the pattern was found to be better than the control pattern which was regarded as the best among 4 patterns created based on existing torso block drafting methods.

• 한국정밀공학회지
• /
• 제16권2호통권95호
• /
• pp.145-152
• /
• 1999

This paper presents the principle and experimental results of a non-contact surface roughness measurement by means of screen projected pattern of lase beam reflected from a polished surface. In the reflected laser beam pattern especially from a fine surface like ground or polished one, light intensity varies from the center fo the image to its boundary as the Gaussian distribution. The standard deviation of a light intensity distribution is assumed to be a good non-contact estimator for measuring the surface roughnes, because the light reflectivity is known to be well related with the surface roughness. This method doesn't need to discriminate between the specularly reflected light and the diffusely reflected one, whereas the scattered laser intensity method must do. Nor it needs to adjust the change of light intensity caused by environmental lights or specimen materials. Reflected laser beam pattern narrowly spreads out in the vertical direction to tiny scratches on the polished surface due to abrasives. The deeper the scratch the more the dispersion, which means the rougher surface. The standard deviation of the pattern is nearly in proportion to the surface roughness. Measurement errors by this method are shown to be below 10 percent compared with those obtained by a common contact method. The inclination of measuring unit from the normal axis causes the measurement errors up to 10 percent for an angle of 4 degree. Therefore the proposed method can be used as an on-the-machine quick roughness estimator within 10 percent measurement error.

• 한국항공우주학회지
• /
• 제39권5호
• /
• pp.442-450
• /
• 2011

회전 블레이드의 모션을 측정하기 위해 스테레오 패턴 인식 (stereo pattern recognition, SPR) 기법을 적용한 측정 시스템을 구성하고 실험을 수행하였다. 시스템 요구사항을 만족시키는 스테레오 카메라를 확보하여 SPR 기반의 측정 시스템을 준비하였다. 시스템의 측정불확도를 계산하기 위한 일련의 실험을 통해, 본 SPR 시스템이 2m~4.2m의 측정 거리에서 0.2mm 이내의 표준불확도를 가짐을 확인하였다. 이를 이용하여 계산한 블레이드 모션의 합성표준불확도는, 리드-래그, 플래핑, 비틀림 운동에 대해 각각 0.296mm, 0.209mm, $0.238^{\circ}$ 이었다. 본 SPR 시스템을 한국항공우주연구원의 소형로터 시험장치에 설치하고 회전속도와 콜렉티브 피치각을 각각 360rpm, 589rpm, 그리고 $0^{\circ}$, $4^{\circ}$, $6^{\circ}$로 바꾸어가며, 지상 제자리비행 조건에서 블레이드의 모션과 탄성 변형을 성공적으로 측정하였다. Higher Harmonic Control Aeroacoustic Rotor Test -II 에서 사용한 측정 시스템과의 비교를 통하여 본 시스템의 장점을 분석하였다.

• 한국의류학회지
• /
• 제32권4호
• /
• pp.641-650
• /
• 2008

In this study, seven models with distinctly different body types were researched and explanatory variables were reviewed. Review was done by using body measurements and the measurements of the appropriate bodice patterns in 1D, 2D, and 3D measurement methods in order to review the pattern making system and the equations for calculating the dimensions of the sleeve caps, which are readily available. Data on human bodies, which can be the criteria for each body part required for the new system for making sleeve cap part, were selected considering conditions such as items with a significantly high contribution rate from the results of regression analysis and the easiness of measurement. As a result of research, an explanatory variable required for the system for making sleeve caps with high general use was extracted. All items with the exception of the waist circumference and upper arm circumference were about the measurement of the form of human bodies, which were newly set in this study. As a result of this study, the equations for calculating the dimensions of each part of the sleeve caps showed distinct differences in comparison to the conventional system of construction.

• 한국소음진동공학회논문집
• /
• 제25권8호
• /
• pp.568-574
• /
• 2015

The present study was conducted by using stereo pattern recognition method(SPR method) to measure the displacement and vibration of an airplane wing in flight condition. A SPR based measurement system was developed using two visible light stereo cameras. The visible light stereo images were processed to obtain marker points by adaptive threshold method and marker filtering technique. The marker points were used to reconstruct 3D point, displacement, and vibration data. The SPR system was installed on F-16 fighter. The wing displacement and vibration were measured in flight condition. Therefore, this paper presents a possibility that SPR based measurement system using visible light stereo camera can be very useful for measuring displacement and vibration of an airplane in flight condition.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 2020년도 학술발표회
• /
• pp.95-95
• /
• 2020

Urban flooding occurs in the form of internal-water inundation on roads and lowlands due to heavy rainfall. Unlike in the case of rivers, inundation in urban areas there is lacking in research on predicting and warning through measurement data. In order to analyze urban flood patterns and prevent damage, it is necessary to analyze flooding measurement data for various rainfalls. In this study, the pattern of urban flooding caused by rainfall was analyzed by utilizing the urban flooding measuring sensor, which is being test-run in the flood prone zone for urban flooding management. For analysis, 2019 rainfall data, surface water depth data, and water level data of a street inlet (storm water pipeline) were used. The analysis showed that the amount of rainfall that causes flooding in the target area was identified, and the timing of inundation varies depending on the rainfall pattern. The results of the analysis can be used as verification data for the urban inundation limit rainfall under development. In addition, by using rainfall intensity and rainfall patterns that affect the flooding, it can be used as data for establishing rainfall criteria of urban flooding and predicting that may occur in the future.