• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.7 no.1
• /
• pp.131-139
• /
• 1987

In this study, characteristics of multi-photos and optimal photographing method are suggested by analyzing the normal case and convergent case with multiple method. The optimal photographing method is applied to deformation measurement of a model miniature structure under loading. Comparing with conventional measurement method in accuracy, efficiency and proprities of application of this method are suggested. As a result, the optimal photographing condition is ideal at $90^{\circ}$ convergent multiple case, whose measurement values approach to that of precision level within $5{\sim}9{\mu}m$ and bring more than about 55% improvement of accuracy comparing with normal case at the number of photos respectively. Therefore application of this method in deformation measurement as well as precision analysis of structures is desired in precision and economical aspect.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.05a
• /
• pp.187-190
• /
• 2002

Confocal microscopy is very popular technology in bio-medical inspection due to its ability to reject background signals and to measure very thin slide of thick specimens, which is called optical sectioning. But intensity of detected signal in fluorescence type confocal microscopy is so small that only 0.2% of emitted fluorescence light can be detected in the best case. In this paper, we proposed the reflecting optical system to improve the detection intensity and designed the optical system by optimal design method. At the end of the paper, we analyzed the characteristics of the proposed reflecting optical system.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.5 no.3
• /
• pp.45-55
• /
• 2002

중거리 유도무기 체계가 탄도탄과 같이 기동이 심한 표적과 교전할 때에는 지상 레이더는 표적 및 유도탄 위치정보를 보다 빈번하게 전송하여야 하지만, 자신의 임무를 수행해야 하므로 유도탄 및 교전 표적에 대한 정보를 필요이상으로 자주 전송할 수 없다. 이러한 상황에서 탐색기가 자체적으로 표적의 거리, 속도, 방향을 측정함으로서 지상레이더에 추가 부담을 지우지 않고 우수한 추적 정밀도로 교전성능을 향상할 시킬 수 있는 고반복 펄스열을 사용하는 PRF 변조방식을 제안한다.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.4
• /
• pp.79-87
• /
• 2004

The light pattern reflected from a machined surface contains some information like roughness and profile on the projected surface as expected in the Beckmann-Spizzichino model. In applying the theory into a real reliable measuring device, many parameters such as incident light power, wave length, spot size should be kept a constant optical value. However, the reflected light power is likely to change with the environmental noise, the variations of the light source, the reflectivity of the surface, etc. even though the incident light power is constant. In this study, a method for adjusting the incident light power to keep the reflected light power projected on a CMOS image sensor constant was proposed and a simple adjustment algorithm based on PI digital control was examined. Experiments verified that the proposed method made the surface roughness measurement better and more reliable even under variations of the height of light source.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.10 no.5
• /
• pp.26-30
• /
• 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.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2016.10a
• /
• pp.699-701
• /
• 2016

최근 산업에서는 기계구성 부품과 고정밀 가공에 대한 요구가 높아지고 있으며, 생산 현장에서는 기계를 효율적으로 운용하는 것의 필요성과 정밀도향상의 요구가 높아지고 있다. 하지만 이를 위해서는 가공된 제품을 정밀히 관찰, 분석 할 수 있어야 하며, 이를 위해서는 사람의 눈으로 볼 수 없는 미세한 차이를 구분 할 수 있어야 한다. 이를 위해서 본 논문에서는 백색광 간섭 측정계를 이용해 측정된 데이터를 시각화 하고, 더 나아가서 6가지의 거칠기 파라미터를 제공하여 관찰, 분석에 있어서 유용한 정보를 제공하고자 한다.

• Proceedings of the KIEE Conference
• /
• 2002.11c
• /
• pp.550-553
• /
• 2002

A source meter is a basic instrument to perform a measurement of DC characteristic of semiconductor devices. the source meter can be used as variable voltage source, variable current source, voltage meter, or current meter. The accuracy of the low current measurement can be improved with the compensation of leakage current and charge and discharge current. In the low current measurement, the RC time constant is extremely big, so the measurement speed is very low. In this thesis, the analysis of the behavior of the measurement current according to the RC time constant and output capacitance and the method to accelerate the measurement speed.

• Proceedings of KOSOMES biannual meeting
• /
• 2017.04a
• /
• pp.254-254
• /
• 2017

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.13 no.6
• /
• pp.139-144
• /
• 2014

As a result of a mismatch of the residual stress between both sides of the silicon wafer, which warps and distorts during the patterning process. The accuracy of the warpage measurement is related to the calibration. A CCD camera was used for the calibration. Performing optimization of the error function constructed with phase values measured at each pixel on the CCD camera, the coordinates of each light source can be precisely determined. Measurement results after calibration was performed to determine the warpage of the silicon wafer demonstrate that the maximum discrepancy is $5.6{\mu}m$ with a standard deviation of $1.5{\mu}m$ in comparison with the test results obtained by using a Form TalySurf instrument.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1996.05a
• /
• pp.309-314
• /
• 1996

가압 경수로형 원전 안전정지/ 안전 주입 변수와 관련된 계기는 관련 기술 기준에 따라 정기 보수시 교정이 이루어지면, 정지 신호를 모의 주입하여 물리량 검출기로 부터 원자로 정지집계 권선의 풀림시간까지의 총 응답 시간이 사고해석시 가정된 계통의 응답 지연시간이내에 들어 있는 지를 확인한다. 이 정지 신호에 응답하는 동적 보상기의 특성과 관련하여 설계과정에서 삽입된 근사화 오차에 대한 정략적인 평가가 이미 알려진 바 있고, 시간 응답 측정시 삽입되는 지연 요소로 인한 오차도 이에 포함시켜 분석한 바 있어 실제 교정시 정밀도 향상을 위하여 활용하고 있다. 이 논문을 통하여 원자로 정지계통의 응답시간 측정시 노 냉각수 평균 온도 변화율 동적 보상 미분-지연 카드에 모의입력으로 스텝신호를 주입할 경우, 이를 과도하게 큰 신호로 인식하여 매우 짧은 시간(1초 이내)에 응답되고, 스텝신호대신 1%P.U./초로 평균온도 변화율만을 주입할 경우, 보다 늦게 응답됨을 밝혔다. 따라서 모의 시험 방범에 있어서 입력 선택을 적합하게 하여야만 계통의 건전성을 응답시간으로 확인한 수 있는 데, 이에 적합한 모의 입력 방법을 제안하였다.