• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.195.1-195.1
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• 2016

Currently, as Plasma application is expanded to the industrial and medical industrial, low temperature plasma applications became important. Especially in medical and biology, many researchers have studied about generated radical species in atmospheric pressure low temperature plasma directly adapted to human body. Therefore, so measurement their plasma parameter is very important work and is widely studied all around world. One of the plasma parameters is electron density and it is closely relative to radical production through the plasma source. some kinds of method to measuring the electron density are Thomson scattering spectroscopy and Millimeter-wave transmission measurement. But most methods have very expensive cost and complex configuration to composed of experiment system. We selected Michelson interferometer system which is very cheap and simple to setting up, so we tried to measuring electron density by laser interferometer with laser beam chopping module for measurement of temporal phase difference in plasma jet. To measuring electron density at atmospheric pressure Ar plasma jet, we obtained the temporal phase shift signal of interferometer. Phase difference of interferometer can occur because of change by refractive index of electron density in plasma jet. The electron density was able to estimate with this phase difference values by using physical formula about refractive index change of external electromagnetic wave in plasma. Our guiding laser used Helium-Neon laser of the centered wavelength of 632 nm. We installed chopper module which can make a 4kHz pulse laser signal at the laser front side. In this experiment, we obtained more exact synchronized phase difference between with and without plasma jet than reported data at last year. Especially, we found the phase difference between time range of discharge current. Electron density is changed from Townsend discharge's electron bombardment, so we observed the phase difference phenomenon and calculated the temporal electron density by using phase shift. In our result, we suggest that the electron density have approximately range between 1014~ 1015 cm-3 in atmospheric pressure Ar plasma jet.

• 대한물리의학회지
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• 제10권4호
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• pp.15-23
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• 2015

PURPOSE: We aims to promote the development of proprioception measurement using smartphones, goniometers, and laser pointers as compared to the conventional use of electrogoniometer measurement. METHODS: Measurements using an electrogoniometer were previously proved to be reliabile and valid. Among E-university students, 20 who had no fracture, operation history, or inflammatory arthritis were examined. These subjects had not performed regular exercise in the past 3 months. Proprioception measurements were performed using four different measurement tools, three times per day, for test-retest analysis. RESULTS: No notable test-retest differences were noted for any of the measurement methods (P>0.05). With regard to the test-retest reliability for each measurement method, we observed that the readings from both the electrogoniometer and smartphone have high reliability (ICC>0.80), whereas the readings from the laser pointer have moderate reliability (ICC>0.60). When assessing the concurrent validity between electrogoniometers with individual measurements, we did not observe any notable difference between the smartphone and electrogoniometer (P>0.05) and these tools in fact showed high correlation (r>0.60, P<0.05) and a moderate reliability (ICC>0.60). Moreover, there was no notable difference in between electrogoniometers and laser pointers (P<0.05). CONCLUSION: CONCLUSION: The findings of this suggested that proprioception can be measured by using smart-phones, and proved that this method has sufficient credibility. Moreover, we noted that the concurrent validity with smartphones was high in comparison with the conventional electrogoniometer, which also indicates the validity and credibility. Based on these findings, we conclude that the measurement of proprioception by using a smartphone can be widely adopted.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2007년도 춘계학술대회 논문집
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• pp.815-816
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• 2007

• 마이크로전자및패키징학회지
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• 제31권2호
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• pp.63-68
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• 2024

최근 투명 디스플레이 및 유연 소자의 활용도가 증가함에 따라 우수한 유연성과 강성을 갖는 폴리머 소재 기판의 사용이 증가하고 있다. 그러나 폴리머는 열에 취약하여 공정 중 온도 및 열 제어가 필수적이다. 이러한 폴리머 기판 활용의 단점을 해결하기 위해 본 연구에서는 레이저 기반의 선택적 가공 기술에 적용할 수 있는 폴리머 기판 내 레이저 가공영역의 온도 측정 시스템을 제안한다. 레이저 가공 영역의 국부적인 온도 변화 측정을 통해 폴리머 기판의 공정 조건을 최적화하는 가능성을 제시한다. 이를 위해 플랑크 흑체 복사 원리를 기반으로 한 PDPT(Photodiode based Planck Thermometry)를 설계 및 제작하여 레이저가 입사되는 영역의 온도를 측정하였다. PDPT는 비파괴/비접촉식 온도측정 시스템으로, 레이저가 입사되는 국부적인 온도 상승을 실시간으로 측정할 수 있다. 해당 시스템을 활용하여 폴리머 기판의 레이저 가공 공정에서 발생하는 가공영역의 온도 변화를 관측하였다. 본 연구 결과, 제안된 레이저 기반 온도측정 기술은 레이저 가공 공정 중 실시간 온도 측정이 가능하며, 이를 통해 최적의 생산 조건을 확립할 가능성을 보여주고 있다. 또한, 해당 기술은 열 제어가 필수적인 미세 레이저 가공 및 3차원 프린팅과 같은 다양한 레이저 기반 공정에 적용될 수 있을 것으로 기대된다.

• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2004년도 추계학술대회 논문집
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• pp.108-111
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• 2004

Laser induced incandescence and laser induced fluorescence techniques have been investigated to measure the concentrations of soot and PAH, respectively. The Nd:YAG and dye lasers were used to form a sheet beam, and its wavelength were modulated to obtain a optimized signals of soot and PAH. Results showed that the relative size groups of soot and PAH can be measured by using our laser techniques.

• 한국공작기계학회논문집
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• 제12권4호
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• pp.36-42
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• 2003

Theodolite measurement system is non-contacted 3-dimensional measurement system. The system accuracy is ${\pm}0.5mm$or better for distance 0~100m. And the system is used for the measurement of a product of middle and large scale. This study is performed for the measurement error factors of the system. We could know that the main measurement error factors are temperature, illumination and skill. Also, we performed the study for the effect according to the height difference of scale bar.

• 제어로봇시스템학회논문지
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• 제22권3호
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• pp.186-191
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• 2016

This paper addresses the development of 3D data acquisition system (3D scanner) based laser structured-light image. The 3D scanner consists of a stripe laser generator, a conventional camera, and a rotation table. The stripe laser onto an object has distortion according to 3D shape of an object. By analyzing the distortion of the laser stripe in a camera image, the scanner obtains a group of 3D point data of the object. A simple semiconductor stripe laser diode is adopted instead of an expensive LCD projector for complex structured-light pattern. The camera has an optical filter to remove illumination noise and improve the performance of the distance measurement. Experimental results show the 3D data acquisition performance of the scanner with less than 0.2mm measurement error in 2 minutes. It is possible to reconstruct a 3D shape of an object and to reproduce the object by a commercially available 3D printer.

• 제어로봇시스템학회논문지
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• 제13권1호
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• pp.39-45
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• 2007

This paper proposes a method of container position measurement using automatic landing system that is estimated by a laser range finder. In the most of container position measurement methods, CCD cameras or laser scanners have been used to get the source data. However those sensors are not only weak for disturbances, for examples, the light, fog, and rain, but also the system cost is high. When the spreader arrives at the goal position, it is still swung by inertia or by wind effect. In this paper, the spreader swung data have been used to find the container position. The laser range finder is equipped in the front side of spreader. It can measure distance and relative position between spreader and container. This laser range finder can be rotated as desired by a motor. And a tilt sensor is equipped on the spreader to measure spreader sway. The relative position information between the spreader and a container using the laser range finder and tilt sensor is estimated through the geometrical analysis.

• 한국항해항만학회지
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• 제28권4호
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• pp.323-331
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• 2004

This paper introduces a novel approach that can provide the three dimensional information about the movement of a spreader by using two CCD cameras and a laser distance measuring unit in order to derive ALS (Automatic Landing System) in the crane used at a harbor. So far a kind of 2D Laser scanner sensor or laser distance measuring units are used as comer detectors for the geometrical matching between the spreader and a container. Such systems provide only two dimensional information which is not enough for an accurate and fast ALS. In addition to this deficiency in performance, the price of the system is too high to adapt to the ALS. Therefore, to overcome these defects, we proposed a novel method to acquire the three dimensional spreader information using two CCD cameras and a laser distance measuring unit. To show the efficiency of proposed method, real experiments are performed to show the improvement of accuracy in distance measurement by fusing the sensory information of the CCD cameras and a laser distance measuring unit.

• 한국자동차공학회논문집
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• 제8권2호
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• pp.64-71
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• 2000

In order to clarify the characteristics of soot formation and oxidation in-cylinder of a diesel engine, it is necessary to diagnose accurately for combustion of in-cylinder. The past techniques for soot measurement have limitations in providing the characteristics of soot in a diesel engine, whereas, laser-based 2D imaging diagnostics have the potential to provide better temporally and spatially resolved measurements of the soot distribution. We rebuilt an optically accessible diesel engine which is similar to the conditions of a conventional engine and tried to measure soot distribution in a cylinder of the diesel engine using laser induced scattering(LIS) and laser induced incandescence(LII). Some results were acquired in this study. LIS and LII signal that show soot distribution of a in-cylinder were taken by ICCD properly. The signal of LIS was intenser than that of LII. Although they have some differences of signal intensity in early combusion period, both of signals show that they are generally similar in late combustion period, after ATDC 50 degree.