• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2007년도 추계 종합학술대회 논문집
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• pp.93-96
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• 2007

안테나의 다양한 응용과 더불어 안테나 제작에 필요한 안테나 특성 측정에 관한 관심이 증대됨으로 안테나 측정 시스템의 정밀도가 더욱 필요하게 되었다. 안테나 측정시 사용자의 수동작을 기반으로 하는 기존의 시스템은 사용자의 위치 보정 작업에 기반을 함으로 오차를 유발한다. 따라서 안테나 특성의 자동 측정 시스템 도입이 필요하다. 본 논문에서는 안테나 자동 측정 시스템을 위한 영상 처리 알고리즘을 제안한다. 제안 알고리즘은 측정실 내에서 표준이득 혼 안테나에 대한 영상 정보 획득하고 획득된 영상 정보로부터 안테나 객체를 추출하고 AUT(Antenna Under Test)와 Probe의 자동 정렬을 위한 파라메터를 추출한다. 또한 장착된 안테나의 무게로 인한 AUT 접합부의 기울어짐과 왜곡 보정을 위한 오차 값을 측정한다.

• 한국정보과학회논문지:소프트웨어및응용
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• 제33권4호
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• pp.418-426
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• 2006

본 논문에서는 수술 도중에 심장내부로 삽입한 초음파 탐침을 통해 획득된 초음파 심장영상에서 강인하게 심장 영역을 고속 자동 분할하는 방법을 제안한다 제안한 방법은 심장 초기 경계 추출, 신뢰도 경쟁을 통한 전체 경계 검출, 회전 국부 방사선 기법을 이용한 국부 경계 보완으로 세 단계로 구성된다. 첫째, 초음파 탐침의 중심에서 방사선을 만들어 각 방사선에서 밝기값 기반 임계값 기법으로 얻어진 심장외부 영역을 이용하여 대략적인 초기 심장영역의 경계를 추출한다. 둘째, 각각의 방사선에서 임계치로 추출된 초기 심장영역의 위치를 포함하여 경계와 영역정보를 이용해 추출된 새로운 후보들과 신뢰도의 경쟁을 수행하여 높은 신뢰성을 가진 심장 경계를 검출한다. 셋째, 방사선 기법으로 경계획득이 어려운 심장의 오목한 영역에서 경계를 따라 회전하면서 국부적으로 방사선 조사법을 적용하여 경계를 보완한다. 제안된 방법은 실제 환자의 심장 수술 도중에 얻어진 초음파 영상에 적용되어 고무적인 결과를 획득했다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.173-176
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• 2002

In this paper, we present the combined 2-D and 3-D algorithms for automatic solder paste inspection. For automatic inspection, optical system for the combined inspection and driving unit is made. One-pass run length algorithm that has fast and efficient memory space is applied to the input image fur extracting solder paste patterns. The path of probe movement is then calculated for an automatic inspection. For a fast 3-D inspection, the phase shift algorithm based on Moire interferometry is also used. In addition, algorithms used in this paper are coded by $MMX^{TM}$. A probe system is manufactured to simultaneously inspect 2-D and 3-D for 10mm$\times$10mm field of view, with resolutions of 10 $\mu\textrm{m}$for both x, y axis and 17 $\mu\textrm{m}$for z axis, and then, experiments on several PCBs are conducted. The processing times of 2-D and 3-D, excluding an image capturing, is 0.039 sec and 0.047 sec, respectively. The credible result with $\pm$ 1$\mu\textrm{m}$uncertainty can be also achieved.

• Journal of the Optical Society of Korea
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• 제15권1호
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• pp.74-77
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• 2011

We report a novel extension of 840 nm wavelength- based spectral domain optical tomography to in vivo/real-time human middle ear diagnosis. The system was designed to access the middle ear region with a specifically dedicated handheld probe. The real-time displaying feature was mandatory for in vivo imaging human subject with the handheld probe, and the system could provide about 20 frames per second for 2048 pixels by 1000 A-scans without using any graphics process units under the Labview platform. The inner ear structure of a healthy male volunteer was imaged with the developed system with the axial and lateral resolutions of $15\;{\mu}m$ and $30\;{\mu}m$, respectively. The application of the OCT technology to early diagnose otitis media(OM) is very promising and could be another extensive branch in the OCT field because it provides the depth resolved image including tympanic membrane (TM) and structures below TM whereas the conventional otoscope technique only gives asurface image of the TM.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.109.4-109
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• 2001

We have developed a laser ultrasonic system for visualization of elastic waves propagating on a solid surface, in order to visualize ultrasonic waves propagating on opaque media. This system can produce a series of successive images as an animation of wave propagation, because of scanning an optical heterodyne probe to measure surface transient displacements. Using this visualization technique, we observed the scattering and diffraction of ultrasonic waves around various shapes of artificial defects, and examined its application to nondestructive inspection. This imaging system provides various kinds of visualization images such as propagation image, amplitude image, arrival time image and velocity image. We have been confident that this technique is available for nondestructive inspection and materials ...

• 한국산학기술학회논문지
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• 제14권12호
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• pp.6066-6071
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• 2013

본 논문에서는 의료용 초음파를 이용하는 로봇 시스템을 위한 3차원 캘리브레이션 방법을 제안한다. 고정된 기준점을 구성하기 위한 캘리브레이션 블록을 제작한 후 옵티컬 트래커(optical tracker)를 이용하여 초음파 프루브(probe)의 위치와 기준점의 위치를 측정한다. 초음파 영상의 픽셀 좌표와 센서로 측정된 위치를 비교하여 6개의 파라미터로 이루어진 초음파 프루브와 영상 내의 픽셀 좌표와의 관계 행렬을 구하고 2개의 파라미터로 이루어진 스케일링 행렬을 계산한다. 정밀한 캘리브레이션을 위해 캘리브레이션 블록 내부 모양과 매질 선택에 대한 적절성을 실험을 통해 검증한다. 제안된 방법은 간단한 형태의 캘리브레이션 블록과 옵티컬 트래커를 사용하여 설치에 많은 시간이 필요하지 않는 장점이 있기 때문에 초음파 영상을 이용하는 로봇 작업에 널리 적용이 가능하다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.404-409
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• 2000

Growth characteristics of silica particles have been studied experimentally using in situ sampling technique from $H_2/O_2TEOS$ diffusion flame with carefully devised sampling probe. Verification of sampling result was done through new method and effects of flame condition and TEOS flow rate on growth characteristics of silica particles were investigated. By comparing particles sampled by thermophoretic sampling in flame with those by collector sampling after probe, particles do not change before and after probe sampling, which was clearly proved from the fact that the result of TEM image analysis makes good agreement with that of SMPS measurement. As flame temperature increases, the effect of coalescence or sintering becomes important mechanism during growth of silica particles, resulting in canceling the effect of coagulation, which makes mean diameter of silica particles increase slowly. With increase in TEOS flow rate, the number concentration of generated silica particle increases but residence time of particles in flame decreases. As a result, there exists upper limit to which the diameter of silica particle increases under same flame condition.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.1900-1902
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• 2005

본 연구에서는 scanning probe microscopy(SPM)을 이용하여 국소영역에서 silicon nanocrystal(Si NC)의 전기적 특성을 분석하였다. Si NCs은 압축된 silicon powder를 laser로 분해하는 laser ablation 방식으로 제조되었고, sharpening oxidation 과정을 통하여 Si NC 주변에 oxide shell을 형성시켰다. 이 과정에서 Si NCs은 $10{\sim}50 nm$의 크기와 약 $10^{11}/cm^2$의 밀도로 $SiO_2$층에 증착되었다. SPM의 conducting tip을 통하여 전하는 각각의 Si NC로 주입되게 되고, 이로 인하여 발생하는 SCM image와 dC/dV curve의 변화를 통하여 Si NC에서 전하 거동을 모니터 하였다. 또한 국소영역에서 Si NC의 전기적 특성을 MOS capacitor 구조에서의 C-V 특성과 비교 분석하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권8호
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• pp.3962-3980
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• 2019

To deal with single sample face recognition, this paper presents a patch based semi-supervised linear regression (PSLR) algorithm, which draws facial variation information from unlabeled samples. Each facial image is divided into overlapped patches, and a regression model with mapping matrix will be constructed on each patch. Then, we adjust these matrices by mapping unlabeled patches to $[1,1,{\cdots},1]^T$. The solutions of all the mapping matrices are integrated into an overall objective function, which uses ${\ell}_{2,1}$-norm minimization constraints to improve discrimination ability of mapping matrices and reduce the impact of noise. After mapping matrices are computed, we adopt majority-voting strategy to classify the probe samples. To further learn the discrimination information between probe samples and obtain more robust mapping matrices, we also propose a multistage PSLR (MPSLR) algorithm, which iteratively updates the training dataset by adding those reliably labeled probe samples into it. The effectiveness of our approaches is evaluated using three public facial databases. Experimental results prove that our approaches are robust to illumination, expression and occlusion.

• Applied Microscopy
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• 제2권1호
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• pp.39-46
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• 1972

There are many kinds of microscopes suitable for general studies; optical microscopes(OM), conventional transmission electron microscopes (TEM), and scanning electron microscopes(SEM). The optical microscopes and the conventional transmission electron microscopes are very familiar. The images of these microscopes are directly formed on an image plane with one or more image forming lenses. On the other hand, the image of the scanning electron microscope is formed on a fluorescent screen of a cathode ray tube using a scanning system similar to television technique. In this paper, the features and some applications of the scanning electron microscope will be discussed briefly. The recently available scanning electron microscope, combining a resolution of about $200{\AA}$ with great depth of field, is favorable when compared to the replica technique. It avoids the problem of specimen damage and the introduction of artifacts. In addition, it permits the examination of many samples that can not be replicated, and provides a broader range of information. The scanning electron microscope has found application in diverse fields of study including biology, chemistry, materials science, semiconductor technology, and many others. In scanning electron microscopy, the secondary electron method. the backscattererd electron method, and the electromotive force method are most widely used, and the transmitted electron method will become more useful. Change-over of magnification can be easily done by controlling the scanning width of the electron probe. It is possible. to continuously vary the magnification over the range from 100 times to 1.00,000 times without readjustment of focusing. Conclusion: With the development of a scanning. electron microscope, it is now possible to observe almost all-information produced through interactions between substances and electrons in the form of image. When the probe is properly focused on the specimen, changing magnification of specimen orientation does not require any change in focus. This is quite different from the conventional transmission electron microscope. It is worthwhile to note that the typical probe currents of $10^{-10}$ to $10^{-12}\;{\AA}$ are for below the $10^{-5}$ to $10^{-7}\;{\AA}$ of a conventional. transmission microscope. This reduces specimen contamination and specimen damage due to heatings. Outstanding features of the scanning electron microscope include the 'stereoscopic observation of a bulky or fiber specimen in high resolution' and 'observation of potential distribution and electromotive force in semiconductor devices'.