• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.1051-1058
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• 2018

This paper propose image processing algorithm to prevent safety accidents near by subway platform screen door(PSD). First, edges of the subway PSD images are detected and the boundary line between PSD and subway platform is detected to decide people's approach to the PSD using Hough transform. To do this, we draw the boundary line between the PSD and platform, to detect the boundary line and to decide the people's approach to the detected line is completely connected or not. Generally, edge is the basic characteristic of image; thus, edge detection is very important in image processing applications and computer vision area. The conventional edge detection methods such as Roberts, Sobel, Prewitt, and Laplacian etc, which are using a fixed value of mask, and morphological gradient from the structuring element of view and Canny edge detector are widely used. In this paper, we propose the detection algorithm about the people's approach to the subway PSD to prevent the safety accidents by using Canny edge detector and Hough transform and the computer simulation shows the results.

• Progress in Medical Physics
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• v.14 no.3
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• pp.203-210
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• 2003

PET (positron emission tomography) permits the investigation of physiological and biochemical processes in vivo. The accuracy of quantifying PET data is affected by its finite spatial resolution, which causes partial volume effects. In this study, we developed a method for partial volume correction using Hoffman phantom PET and MR data, and applied various FWHM (full width at half maximum) levels. We also applied this method to PET images of normal controls and tested for the possibility of clinical application. $^{18}$ F-PET Hoffman phantom images were co-registered to MR slices. The gray matter and white matter regions were then segmented into binary images. Each binary image was convolved by 4, 8, 12, 16 mm FWHM levels. These convolved images of gray and white matter were merged corresponding to the same level of FWHM. The original PET images were then divided by the convolved binary images voxel-by-voxel. These corrected PET images were multiplied by binary images. The corrected PET images were evaluated by analyzing regions of interests, which were drawn on the gray and white matter regions of the original MR image slices. We calculated the ratio of white to gray matter. We also applied this method to the PET images of normal controls. On analyzing the corrected PET images of Hoffman phantom, the ratios of the corrected images increased more than that of the uncorrected images. With the normal controls, the ratio of the corrected images increased more than that of the uncorrected images. The ratio increase of the corrected PET images was lower than that of the corrected phantom PET images. In conclusion, the method developed for partial volume correction in PET data may be clinically applied, although further study may be required for optimal correction.

• The Korean Journal of Nuclear Medicine
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• v.30 no.3
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• pp.372-378
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• 1996

In the case of $^{123}I$ from the $^{124}Te$(p,2n)reaction, the radionuclidic impurity is the high-energy gamma-emitting $^{124}I$, which interferes greatly with nuclear medicine images. The choice of a collimator can affect the quality of clinical SPECT images of [I-123]MIBG, [I-123] ${\beta}$-CIT, or [I-123]IPT. The tradeoffs that two different collimators make among spatial resolution, sensitivity, and scatter were studied by imaging a line source at 5cm, 10cm, 15cm distance using a number of plexiglass sheets between source and collimator, petri dish, two-dimensional Hoffman brain phantom, Jaszczak phantom, and three-dimensional Hoffman brain phantom after filling with $^{123}I$. (FWHM, FWTM, Sensitivity) for low-energy ultrahigh-resolution parallel - hole (LEUHRP) collimator and medium- energy general - purpose (MEGP) collimator were measured as (9.27mm, 61.27mm, $129CPM/{\mu}Ci$) and (10.53mm, 23.17mm, $105CPM/{\mu}Ci$), respectively. The image quality of two-dimensional Hoffman brain phantom with LEUHRP looked better than the one with MEGP. However, the image quality of Jaszczak phantom and three-dimensional Hoffman brain phantom with LEUHRP looked much worse than the one with MEGP because of scatter contributions in three-dimensional imaging situation. The results suggest that the MEGP is preferable to LEUHRP for three-dimensional imaging studies of [I-123]MIBG, [I-123] ${\beta}$-CIT, or [I-123]IPT.

• Proceedings of the Korean Society of Crop Science Conference
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• 1988.07a
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• pp.50-51
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• 1988

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.86-90
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• 1992

스크류 압축기는 진동이 작고 맥동이 적으며, 소형이고 고효율이라는 특징이 있다. 또한 식품, 화학, 전자공업 등에서 무윤활식 압축기로 사용되어지고 있다. 본 연구에서는 호프로 자른 것과 같은 다각형 오차를 만들지 않고 매끄러운 면을 얻을 수 있는 스크류 로터의 축직각 단면좌표를 이용한 cutter의 형상을 설계하는 것을 목적으로 한다.

• Journal of Plant Biology
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• v.18 no.2
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• pp.59-85
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• 1975

With a view to obtaining basic informations on the morphological, physiological and ecological aspects of hop in Korea, this experiments were conducted in 4 locations (Suwon, Hongchun, Pyungchang and Hoengsung) from 1972 to 1974. The varieties used in this experiments were Hallertau, Saaz, Shinshuwase and Cascade. the results obtained are summarized as follows.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2001.05a
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• pp.87-91
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• 2001

This paper discusses the influence of input conductance on the convergece of the continuous Hopfield neural networks. The convergence has been analyzed for the input and output nodes of neurons. Also, the characteristics of equilibrium points has been analyzed depending on different values of the input conductance.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.45.2-45.2
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• 2015

우리는 최근 현대천문학의 가장 오래된 난제로 우리은하 헤일로의 형성과 깊은 관련이 있는 구상성단계의 오스터호프 이분법이 다중항성종족 패러다임 하에서 76년 만에 완벽히 규명되는 것을 발견하였다. 또한 이 연구의 기본 개념을 우리은하 벌지에 적용한 결과, 기존 국제학계의 이론과 완전히 다른 벌지의 형성기원에 대한 새로운 해석에 도달하였다. 우리은하의 벌지에 대한 대규모 측광 서베이 분석으로부터 double red clumps가 있다는 것이 2010년에 발견되었고, 이는 디스크와 바 불안정에 기인하는 은하중심부 X-shape 구조의 증거로 널리 받아들여지고 있다. 그러나 우리는 이와 같은 국제학계의 해석이 수평계열성의 항성진화이론을 간과한데서 비롯된 허구일 가능성을 제시하고자 한다. 우리의 모델에 의하면 관측된 double red clumps는 Omega Cen을 포함하는 대다수의 구상성단에서 발견되는 것과 동일한 헬륨함량이 증가된 2세대 별들(G2)에 의한 효과이다. 우리은하 벌지에 위치한 Terzan 5 구상성단처럼, 중원소함량이 높은 벌지에서는 G2에 해당하는 수평계열성들이 광도가 약 0.5등급 더 밝은 red clump 위치에 놓이게 되어 자연스럽게 double red clumps를 형성하게 된다. 앞으로 우리의 새로운 해석이 Gaia에 의한 삼각시차 거리결정으로 확인된다면, 이는 우리은하 벌지를 이루는 대부분의 별들이 Terzan 5와 같은 윈시 빌딩블럭들의 합병과 붕괴에 의해 형성되었다는 것을 암시하여, 우리은하는 물론, 조기형은하의 형성기원 연구에 큰 전환점이 될 것으로 기대한다.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.36S no.6
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• pp.45-56
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• 1999

This paper presents a method for designing an autopilot of the BTT missile using 2DOF Wiener-Hopf control technique to improve tracking performance. Linear controllers are designed based on the linearized models which are obtained from the nonlinear missile dynamic equations at various operating points. The gain scheduling technique is used to implement the final autopilot. A simulation on the flight of missiles is carried out through the use of 6DOF equation program including exact nonlinear equations of the missile and the variations of aerodynamic variables in order to check applicability of the suggested method in real situation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.6
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• pp.1482-1489
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• 1998

This paper aims to extract characteristics of the spectrum of fingerprint image and to apply them to image enhancement techniques in spatial frequency domain. Based on 1$\times$64 window as a processing unit and the different record lengths(32, 16, 8), the estimate of power spectrum density for each length was made. Each acquired spectrum characteristics was applied to the re-synthesis process of the fingerprint image, an improved gray scale image was obtained. In order to select an optimal predictor and the Huffman table for the fingerprint iamge, the lossless JPEG algorithm was used. Experiments were performed for extracting distribution characteristics for the each of 7 predictors from the fingerprint image and modeling processes, and the result was applied to the data compression algorithm and the selection of the optimal predictor.