• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.24 no.2
• /
• pp.188-194
• /
• 2000

Thermochromic liquid crystal reflect a unique color at even temperature. Therefore, they have been successfully applied to non-intrusive heat transfer research. Hue capturing method is widely used in the quantitative measurement from the TLC image. However it is affected by several measurement conditions. The distances of camera and light source have little influence on the color, but the value of hue is seriously affected by the measurement angle. In this study, the hue capturing method is improved by considering the effect of measurement angle. This improved calibration method can diminish the misreading of temperature caused by curvature of test surface.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.6
• /
• pp.1157-1164
• /
• 2007

In this paper, we implement a PDA(Personal Digital Assistant)-based audiometric system in order to estimate hearing threshold by adopting both pure-tone sound and speech audiometric test system. To estimate a subject's hearing threshold in an ambulatory audiometric test environment, an efficient sound calibration scheme between a PDA and a headphone device is proposed by appling polynomial fitting algorithms in 8-banded frequency ranges.

• Proceedings of the KIEE Conference
• /
• 2006.07d
• /
• pp.1947-1948
• /
• 2006

본 논문에서는 컴퓨터로 정밀 계측기기들을 자동 제어하고 데이터를 측정하기 위하여 기존의 상용 프로그램을 사용하지 않고 Excel VBA(Visual Basic for Applications)를 이용하는 방법에 대하여 연구하였다. 이는 반복측정 및 통계적 수치계산 등에서 많은 장점을 지니고 있어 수많은 국가교정기관 및 일반 산업체에서 유용하게 사용될 수 있으리라 사료된다.

• Proceedings of the KIEE Conference
• /
• 2002.11c
• /
• pp.601-604
• /
• 2002

In this paper, the timing do-skew modeling for a high speed logic tester channels is developed. The time delay of each channel in a logic tester are different from other channels and it can produce timing error in a test. To get the best timing accuracy in the test with a logic tester, the timing skew must be compensated. The timing skew of channels is due to the difference of time delay of pin-electronics devices composing channels and length of metal line placed on PCB. The expected timing difference of channels can be calculated according to the specifications of pin electronics devices and strip line modeling of PCB. With the calculated delay time, the timing skew compensation circuit has been designed. With the timing skew compensation circuit, the timing calibration of a logic tester can be peformed easily and automatically without other time measuring instruments. The calibration method can then be directly applied to logic testers in mass production lines.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.55 no.10
• /
• pp.499-503
• /
• 2006

This paper deals with a new two dimensional clinometer based on dual axis micromachined accelerometers. The clinometer is a small and low-cost product, which is mainly developed to help golfers read easily the tilt of a putting green. First, this paper proposes the principle of two dimensional clinometer and also a calibration method with respect to the offset voltage and sensitivity of a accelerometer. Experimental results on the developed clinometer show that the proposed clinometer can provide useful information on the tilt angle and direction of an inclined plane.

• Transactions of Materials Processing
• /
• v.7 no.6
• /
• pp.575-585
• /
• 1998

An automated surface-strain measuring system using the image processing technique is developed in the present study which consists of the hardware to capture and to display digital images. and the software to calculate the 3-D informations of grid points from two views. New or improved algorithms for the mapping and establishing correspondence of grid points and elements the camera calibration and the subpixel measurement of grid points are implemented. As an application of the present system the surface-strains of deformed blanks in the limitting dome height test the square cup deep-drawing and punch stretching to obtain the forming limit diagram are measured. The results are com-pared with those obtained by conventional manual methods.

• Journal of Korea Multimedia Society
• /
• v.24 no.9
• /
• pp.1261-1267
• /
• 2021

Currently, the application of virtual reality technology is becoming more and more popular in all aspects of life. From virtual entertainment to industrial simulation, the new operation and working methods brought by virtual reality visualization technology have greater appeal and advantages. With the renewal and iteration of related equipment, more and more functions make its limitations continue to decrease, but its applicability continues to improve. Take the optically transparent head-mounted device as an example. It integrates more computer functions, presents and interacts in a virtual way, further integrates with daily behaviors, and shortens the distance between users and digital information.

• Current Optics and Photonics
• /
• v.8 no.4
• /
• pp.327-344
• /
• 2024

Optical phantoms are essential in optical imaging and measurement instruments for performance evaluation, calibration, and quality control. They enable precise measurement of image resolution, accuracy, sensitivity, and contrast, which are crucial for both research and clinical diagnostics. This paper reviews the recent advancements and challenges in phantoms for optical coherence tomography, photoacoustic imaging, digital holographic microscopy, optical diffraction tomography, and oximetry tools. We explore the fundamental principles of each technology, the key factors in phantom development, and the evaluation criteria. Additionally, we discuss the application of phantoms used for enhancing optical-image quality. This investigation includes the development of realistic biological and clinical tissue-mimicking phantoms, emphasizing their role in improving the accuracy and reliability of optical imaging and measurement instruments in biomedical and clinical research.

• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.915-916
• /
• 2002

최근 산업체 및 국가교정검사기관에서 교정용 표준기급으로 많이 사용하고 있는 Digital Multimeter(HP 3458A)의 수동교정과 불확도 평가후 성적서 발급까지 5시간 정도가 소요된다. 이러한 교정시간을 단축시키고 객관적인 양질의 교정data를 얻을수 있는 교정자동화 프로그램을 개발하였다. 이 프로그램은 Labview를 이용하여 작성하였고 교정부터 불확도평가후 성적서 발급까지 자동적으로 1시간내에 수행이 된다. 또한 기존의 수동교정에 의한 결과와 비교했을 때 불화도 범위 내에서 동일한 결과를 얻었다.

• Proceedings of the KIEE Conference
• /
• 1987.07b
• /
• pp.1301-1304
• /
• 1987

We have analized electrical error factors generated in the digitizing process of the linear scanning digital radiography system, and obtained improved results using error calibration hardwares. And characteristics of digital radiography system were evaluated by measuring several imaging properties.