• 한국정밀공학회지
• /
• 제3권1호
• /
• pp.69-76
• /
• 1986

The measuring Method by stylus, which measures surface roughness, has been widely used since G. Schmaltz developed the first equipment of that type. Withe the resent development of the measuring method by stylus, surface foughness testing instruments of the very high magnification ratio, hundreds of thousands, are manu- factured. However, as the techniques of the high precision roughness measurement are being required, the response problems due to the tip shapes and the plastic deformations of measured surface of mild material are to be serious factors. In this study, diamond stylus of tip radius $0.5\mu\textrm{m}$, $2\mu\textrm{m}$, $5\mu\textrm{m}$ and $10\mu\textrm{m}$ were used under the measuring force of 0.01gf, 0.02gf, 0.07gf, 0.4gf and 1.6gf, and from the experimental data, maximum measured value devrements between $2\mu\textrm{mR}$ stylus and $5\mu\textrm{mR}$ stylus, $2\mu\textrm{mR}$ stylus and $10\mu\textrm{mR}$ stylus are 22% and 31%, respectively when the measured value of $2\mu\textrm{mR}$ stylus goes to $0.01\mu\textrm{m Ra}$, $\lambda$ c2.5mm. And it is shown that plastic deformations on the plastic deformations on the measured surface are proportional to W/R(W;measured force, R;stylus tip radius).

• 제어로봇시스템학회논문지
• /
• 제19권11호
• /
• pp.979-983
• /
• 2013

The three-dimensional measurement method of confocal systems is a spot scanning method which has a high resolution and good illumination efficiency. However, conventional confocal systems had a weak point in that it has to perform XY axis scanning to achieve FOV (Field of View) vision through spot scanning. There are some methods to improve this problem involving the use of a galvano mirror [1], pin-hole array, etc. Therefore, in this paper we propose a method to improve a parallel mode confocal system using a micro-lens and pin-hole array in a dual microscope configuration. We made an area scan possible by using a combination MLA (Micro Lens Array) and pin-hole array, and used an objective lens to improve the light transmittance and signal-to-noise ratio. Additionally, we made it possible to change the objective lens so that it is possible to select a lens considering the reflection characteristic of the measuring object and proper magnification. We did an experiment using 5X, 2.3X objective lens, and did a calibration of height using a VLSI calibration target.

• 한국컴퓨터정보학회논문지
• /
• 제13권3호
• /
• pp.179-187
• /
• 2008

본 논문에서는 자궁 경부 세포진 영상에서 세포핵의 후보 영역과 핵을 추출하기 위해 현미경 400배율 확대 사진을 획득하는 과정에서 훼손된 컬러 영상을 복원하기 위한 방법으로 Lighting Compensation을 적용하여 영상을 보정한다. 그리고 배경 영역과 세포핵 영역을 구분하기 위해 영상의 R,G,B 영역의 히스토그램의 분포를 이용하여 배경을 제거한다. 배경이 제거된 영상을 그레이 영상으로 변환 한 후, 히스토그램 명암도의 값을 이용하여 세포핵영역과 세포질을 분류하여 세포핵 영역을 추출한다. 그리고 Kapur 방법을 적용하여 세포핵 영역의 엔트로피 누적확률을 구한 후, 영상을 이진화한다. Kapur 방법이 적용된 이진화 영상에서 세포핵 영역의 중심과 주위 화소를 비교하는 $3{\times}3$ 마스크를 적용하여 영상의 미세한 잡음을 제거 한 후, 8 방향 윤곽선 추적 알고리즘을 적용하여 최종적으로 세포핵 영역을 추출한다. 추출된 세포핵의 영역을 분류 및 인식하는 과정으로 세포의 외각의 방향성 정보, 핵의 크기, 그리고 면적 비율의 특징을 이용하여 퍼지 소속 함수를 설계한 후, 소속 함수의 소속도를 구하고 퍼지추론 규칙을 적용하여 자궁 경부 세포진 영상에서 정상 세포핵 및 암종 세포핵을 인식한다.

• 한국태양에너지학회 논문집
• /
• 제40권5호
• /
• pp.23-34
• /
• 2020

Concentrator photovoltaic (CPV) system consists of high-quality complex optical elements, mechanical devices, and electronics components and can have the advantages of high integration and high-efficiency energy sources. III-V compound semiconductor cells have proven performance based on high reliability in the aerospace field, but have characteristics that require absolute support of the balance of systems (BOS) such as solar position trackers, receivers with heat sinks, and housing instruments. To determine the optimum parameters of secondary optical elements (SOEs) design for CPV systems, we designed three types of CPV modules, classified as non-SOEs type, reflective mirror type, and CPC lens type. We measured the I-V and P-V characteristics of the prototype CPV modules with the angle of inclination varying from 0° to 12° and with a 500-magnification Fresnel lens. The experimental results assumed misalignment of the solar position tracker or module design of pinpoint accuracy. As a result, at the 0° tilt angle, the CPC lens produced lower power due to the quartz transmittance ratio compared to that by other SOEs. However, for tilt angles greater than 3°, the CPC lens type module achieved high efficiency and stability. This study is expected to help design high-performance CPV systems.

• International Journal of Precision Engineering and Manufacturing
• /
• 제8권2호
• /
• pp.70-74
• /
• 2007

This paper describes the development of a nano-positioning system for nanoscale science and engineering. Conventional positioning systems, which can be expensive and complicated, require the use of laser interferometers or capacitive transducers to measure nanoscale displacements of the stage. In this study, a new self-displacement sensing (SDS) nano-stage was developed using mechanical magnification of its displacement signal. The SDS nano-stage measured the displacement of its movement using a position-sensitive photodiode (PSPD), a laser source, and a hinge-connected rotating mirror plate. A beam from a laser diode was focused onto the middle of the plate with the rotating mirror. The position variation of the reflected beam from the mirror rotation was then monitored by the PSPD. Finally, the PSPD measured the amplified displacement as opposed to the actual movement of the stage via an optical lever mechanism, providing the ability to more precisely control the nanoscale stage. The displacement amplification process was modeled by structural analysis. The simulation results of the amplification ratio showed that the distance variation between the PSPD and the mirror plate as well as the length L of the mirror plate could be used as the basic design parameters for a SDS nano-stage. The PSPD was originally designed for a total travel range of 30 to 60 mm, and the SDS nano-stage amplified that range by a factor of 15 to 25. Based on these results, a SDS nano-stage was fabricated using principle of displacement amplification.

• Restorative Dentistry and Endodontics
• /
• 제25권2호
• /
• pp.202-211
• /
• 2000

The aim of this study was to compare the apical sealing ability of a new thermoplasticized gutta-percha filling technique, the Easy Filling and the Quick Obturation system with lateral condensation technique and Thermafil system to evaluate their clinical acceptabilities. Fifty-two extracted single-rooted teeth were instrumented to #35 using the .04 taper ProFile system. Four groups of 12 teeth were obturated by lateral condensation technique. Thermafil system and two new thermoplasticized gutta-percha techniques, the Easy Filling system and Quick Obturation system (Meta Dental co. Ltd. Korea), respectively. Four teeth served as controls. After the teeth were immersed in 2% methylene blue dye for 48 hours, they were resected horizontally at 1mm to 5mm level from the anatomical apex using a low-speed microtome. Each section was examined under a stereomicroscope at ${\times40}$ magnification and photographed. After each image was scanned, the leakage area was measured at each level using Brain 3 (Nosdia Tech., Korea) software. Leakage ratio was calculated for each group and was analyzed statistically to come up with the following results: 1. At 1mm level, the Quick Obturation system had the largest amount of apical leakage and it was statistically significant when compared with the lateral condensation group and the Thermafil group (p<0.05). 2. At 2mm and 3mm level, there were no significant difference of apical leakage among all four groups (p>0.05), and from 4mm level, no apical dye penetration was observed in all the groups. In conclusion, the apical seal produced by Easy Filling system and the Quick Obturation system was comparable to lateral condensation technique and Thermafil system except for the 1mm level. More improvement of the apical seal can be expected as the operator becomes skillful with the new techniques.

• 한국컴퓨터정보학회논문지
• /
• 제18권11호
• /
• pp.59-68
• /
• 2013

본 논문에서는 영상에 존재하는 단순 볼록 곡면과 단순 오목 곡면을 추정하기 위한 효과적인 기법을 제안하였고 이 기법을 확대하고자 하는 입력 영상에 적용하여 단순 볼록 곡면 혹은 단순 오목 곡면을 갖는지 추정한다. 단순 볼록 곡면 혹은 단순 오목 곡면을 갖는 경우, 곡면의 특성이 충실하게 반영되도록 보간값을 구하는 효율적인 기법을 제안하였다. 본 논문에서 제안된 기법들을 적용하여 구한 보간 픽셀값들을 사용하여 구성된 확대 영상은 기존의 기법들에 의한 확대 영상보다 실제 영상에 더욱 충실하게 된다. 제안된 기법을 적용하여 구성된 확대 영상의 화질을 측정하기 위하여 PSNR(Peak Signal to Noise Ratio)을 사용하였다. 제안된 기법들을 적용한 확대 영상들의 PSNR값이 기존의 기법들을 적용한 확대 영상들의 PSNR값보다 큰 것을 실험을 통하여 확인하였다.

• 반도체디스플레이기술학회지
• /
• 제21권1호
• /
• pp.148-154
• /
• 2022

As the 4th industrial age approaches, the demand for semiconductors is increasing enough to be used in all electronic devices. At the same time, semiconductor technology is also developing day by day, leading to ultraprecision and low power consumption. Semiconductors that keep getting smaller generate heat because the energy density increases, and the generated heat changes the shape of the semiconductor package, so it is important to manage. The temperature change is not only self-heating of the semiconductor package, but also heat generated by external damage. If the package is deformed, it is necessary to manage it because functional problems and performance degradation such as damage occur. The package burn in test in the post-process of semiconductor production is a process that tests the durability and function of the package in a high-temperature environment, and heat dissipation performance can be evaluated. In this paper, we intend to review a new material formulation that can improve the performance of the adapter, which is one of the parts of the test socket used in the burn-in test. It was confirmed what characteristics the basic base showed when polyamide, a high-molecular material, and alumina, which had high thermal conductivity, were mixed for each magnification. In this study, functional evaluation was also carried out by injecting an adapter, a part of the test socket, at the same time as the specimen was manufactured. Verification of stiffness such as tensile strength and flexural strength by mixing ratio, performance evaluation such as thermal conductivity, and manufacturing of a dummy device also confirmed warpage. As a result, it was confirmed that the thermal stability was excellent. Through this study, it is thought that it can be used as basic data for the development of materials for burn-in sockets in the future.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• 제21권2호
• /
• pp.174-188
• /
• 1999

통상적으로 사용되는 두부 계측 방사선기기를 이용하여 12개 건조 두개골의 중요한 방사선학적 계측점에 금속구를 위치시킨 후 정모와 측모 두부 방사선사진상을 촬영하고, 이를 바탕으로 얻어진 3차원 두부 방사선사진이 어느 정도의 정확도와 정밀도를 가지고 있는지 알아 보고자 하였다. 또한 이러한 입체 영상을 얻을수 있는 프로그램으로 실제 두명의 악변형증 환자에게 적용시켜 다음과 같은 결과를 얻었다. 1. Nasion relator 를 이용하여 두부위치를 고정한 상태에서 각각 촬영된 정모와 측모 두부 방사선사진으로 3차원 두부 방사선사진을 작성해 본 결과, 촬영시 두부의 위치적 변화에 따른 계측치의 차이는 $0.34{\pm}0.33mm$로 나타나 위치적 변화는 거의 없었다. 즉 동일한 두개골에 대한 3차원 계측치의 x, y, z 축상의 위치 편차가 거의 없었다. 2. 실계측치와 3차원 계측치의 차이는 평균 $1.47{\pm}1.45mm$ 크게 나타났으며 실측치에 대한 3차원 계측치의 확대율은 $100.24{\pm}4.68%$였으며, 차이가 평균보다 크게 나타난 일부 항목의 경우 측모 두부 방사선사진에서 정확한 위치를 잡아내기 어려웠던 계측점이 많았다. 즉, 3차원 계측거리가 실측치와 차이를 보이는 것은 방사선 사진촬영시 위치의 재현성과 관련된 것이라기 보다는 계측점의 식별이 더 크게 좌우된 것으로 보여진다. 3 정모와 측모 두부 방사선사진의 경우 필름과 평행한 시상면에 놓이지 않은 계측항목의 축소가 두드러졌으며 건조 두개골의 크기나 형태에 따라 필름간의 거리가 상이하였기 때문에 수평적, 수직적 확대율의 일관된 경향을 발견할 수 없었다. 실측치와의 차이는 정모 두부 방사선 사진이 $4.72{\pm}2.01mm$, 측모 두부 방사선사진이 $-5.22{\pm}3.36mm$로 나타났으며 수평 계측치보다 수직 계측치가 약간 더 실측치에 근접하는 것을 볼 수 있었다. 4. 실제 악교정수술 환자에게 적용해 본 결과, 계측항목의 수치적 분석보다는 악골자체의 이동량이나 변화의 정도, 비대칭의 분석등에 사용하는 것이 임상적으로 더 의의가 있으며 교정환자의 경우 정모와 측모 모두에서 명확히 나타나는 브라켓을 계측 기준점으로 할 경우 보다 정확한 계측을 할 수 있을 것으로 사료된다.

• 대한디지털의료영상학회논문지
• /
• 제12권2호
• /
• pp.119-125
• /
• 2010

In order to demonstrate the value of long-distance radiography, we have studied how distance affects images in chest frontal radiography and compared short-distance and long-distance images in chest lateral radiography. Cardiothoracic ratio(CTR %) of 50 patients with no disease in the chest(10 each at the age of 20~60) were evaluated in Supine AP(100 cm), Sitting AP(100 cm), Sitting AP(180 cm), and Erect PA(180 cm). In lateral radiography, we evaluated and compared left lateral radiography(100 cm and 180 cm) of the patients based on the horizontal maximum of the heart. The average value of CTR(%) were 0.48 in Erect PA(180 cm), 0.52 in Supine AP(100 cm), 0.50 in Sitting AP(100 cm), 0.49 in Sitting AP(180 cm), which were Supine AP(100 cm) > Sitting AP(100 cm) > Sitting AP(180 cm) > Erect PA(180 cm). The average value of Maximum transverse diameter of left of the cardiac(MLD), which showed how much axis of spine was slanted to the left, was 90.67 mm in Erect PA(180 cm), 103.92 mm in Supine AP(100 cm), 93.54 mm in Sitting(100 cm), 89.84 mm in Sitting AP(180 cm), 58.11 mm in the minimum value and 118.79 mm in the maximum value. The average value of Maximum transverse diameter of right side of the cardiac(MRD), which suggested how much axis of spine was slanted to the right, was 47.18 mm in Erect PA(180 cm), 48.12 mm in Supine AP(100 cm), 44.98 mm in Sitting AP(180 cm), and the minimum value 26.84 mm and the maximum value 65.30 mm. There was no standard method to calculate; therefore, the horizontal maximum of the heart was used for lateral radiography. The average value was 121.07 mm in 100 cm and 109.76 mm in 180 cm. Sitting AP(180 cm) among the types was closest to C-PA(180 cm). As a result, during C-AP radiography, long-distance radiography lessened shadow of the heart more than that of short distance, Sitting position more than Supine position.