• Proceedings of the KSRS Conference
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• v.2
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• pp.643-646
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• 2006

This paper addresses the approach to extract linear features from satellite imagery using an efficient segmentation method. The extraction of linear features from satellite images has been the main concern of many scientists. There is a need to develop a more capable and cost effective method for the Iranian map revision tasks. The conventional approaches for producing, maintaining, and updating GIS map are time consuming and costly process. Hence, this research is intended to investigate how to obtain linear features from SPOT satellite imagery. This was accomplished using a discontinuity-based segmentation technique that encompasses four stages: low level bottom-up, middle level bottom-up, edge thinning and accuracy assessment. The first step is geometric correction and noise removal using suitable operator. The second step includes choosing the appropriate edge detection method, finding its proper threshold and designing the built-up image. The next step is implementing edge thinning method using mathematical morphology technique. Lastly, the geometric accuracy assessment task for feature extraction as well as an assessment for the built-up result has been carried out. Overall, this approach has been applied successfully for linear feature extraction from SPOT image.

• Progress in Superconductivity
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• v.5 no.2
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• pp.94-97
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• 2004

Step-edge Josephson junctions (SEJ) have been fabricated on sapphire substrates with in situ deposited films of CeO$_2$ buffer layer and YBa$_2$Cu$_3$O$_{7}$ films on the low angle steps. Direct coupled SQUID magnetometers with the SEJ were formed on 1 cm X 1 cm R-plane sapphire substrates. Typical 5-${\mu}{\textrm}{m}$-wide Josephson junctions have R$_{N}$ of 3 Ω and I$_{c}$ of 50 $mutextrm{A}$ at 77 K. The direct coupled SQUID magnetometers were designed to have pickup coils of 50-${\mu}{\textrm}{m}$-wide 16 parallel loops on the 1 cm X 1 cm substrates with outer dimension of 8.8 mm X 8.8 mm. The SEJ SQUID magnetometers exhibit relatively low 1/f noise even with dc bias control, and could be stably controlled by flux-locked loops in the magnetically disturbed environment. Field noise of the do SQUID was measured to be 200∼300 fT/Hz$^{1}$2/in the white noise region and about 2 pT/Hz$^{1}$2/ at 1 Hz when measured with dc bias method.hod.d.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.9
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• pp.2312-2325
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• 2013

In this paper, we propose a preprocessing method that it is to correct the distortion of text area in Korean signboard images as a preprocessing step to improve character recognition. Distorted perspective in recognizing of Korean signboard text may cause of the low recognition rate. The proposed method consists of four main steps and eight sub-steps: main step consists of potential vertical components detection, vertical components detection, text-boundary estimation and distortion correction. First, potential vertical line components detection consists of four steps, including edge detection for each connected component, pixel distance normalization in the edge, dominant-point detection in the edge and removal of horizontal components. Second, vertical line components detection is composed of removal of diagonal components and extraction of vertical line components. Third, the outline estimation step is composed of the left and right boundary line detection. Finally, distortion of the text image is corrected by bilinear transformation based on the estimated outline. We compared the changes in recognition rates of OCR before and after applying the proposed algorithm. The recognition rate of the distortion corrected signboard images is 29.63% and 21.9% higher at the character and the text unit than those of the original images.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.83-86
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• 1999

We have fabricated $_2Cu_3O_7$ step-edge junctions with different step orientations and studied their transition properties. Steps with different orientations were prepared on the substrate. Josephson junctions were made on a single substrate with step orientations ranging from 0$^{\circ}$ to 165$^{\circ}$ at 15$^{\circ}$ interval. We measured current-voltage characteristics, the critical current, and the superconducting transition temperature as a function of the angle. The critical current showed a modulation that has a maximum near 0$^{\circ}$ or 90$^{\circ}$ and a minimum near 45$^{\circ}$ and 135$^{\circ}$. We believe that the critical current modulation with the step orientation could be associated with the symmetry of high T$_c$ superconductor.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.6
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• pp.663-671
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• 1988

In this paper, in order to reduce the blocking effect of block coded images, we propose the method considering the lowpass and bandpass components of Granrath's human visual model. This method consists of two-stage enhancement procedure. The first step is lowpass filtering which smooths out the blocking effect, and the second step is a high frequency enhancement procedure to increase the contrast decreased by the lowpass filtering in the first step. In the first step, the one-dimensional Gaussian filter which aligthns parallel to the edge direction is considered to preserve the edge in the block and the two-dimensional Gaussian filter is used to smooth out the blocking effect near the block boundaries. In the second step, the lowpass and bandpass components of the Granrath's model are considered to increase contrast in a restored image. The performance comparison of the proposed method and the existing mehtods is made by a computer simulation with several block coded images. We can see that the enhancement in the subjective quality of images of the proposed method is more significant than the enhancement in the subjective quality of images of the proposed method is more significant than the existing methods, though the proposed method does not show better performance on the PSNR gain, the poor measure of picture quality for block coded images.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.463-463
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• 2012

ITRS (international technology roadmap for semiconductors)에 따르면 MOS(metal-oxide-semiconductor)의 CD (critical dimension)가 45 nm node이하로 줄어들면서 poly-Si/$SiO_2$를 대체할 수 있는 poly-Si/metal gate/high-k dielectric이 대두된다고 보고하고 있다. 일반적으로 high-k dielectric를 식각시 anisotropic 한 식각 형상을 형성시키기 위해서 plasma를 이용한 RIE (reactive ion etching)를 사용하고 있지만 PIDs (plasma induced damages)의 하나인 PIED (plasma induced edge damage)의 발생이 문제가 되고 있다. PIED의 원인으로 plasma의 direct interaction을 발생시켜 gate oxide의 edge에 trap을 형성시키므로 그 결과 소자 특성 저하가 보고되고 있다. 그러므로 본 연구에서는 이에 차세대 MOS의 high-k dielectric의 식각공정에 HDP (high density plasma)의 ICP (inductively coupled plasma) source를 이용한 원자층 식각 장비를 사용하여 PIED를 줄일 수 있는 새로운 식각 공정에 대한 연구를 하였다. One-monolayer 식각을 위한 1 cycle의 원자층 식각은 총 4 steps으로 구성 되어 있다. 첫 번째 step은 Langmuir isotherm에 의하여 표면에 highly reactant atoms이나 molecules을 chemically adsorption을 시킨다. 두 번째 step은 purge 시킨다. 세 번째 step은 ion source를 이용하여 발생시킨 Ar low energetic beam으로 표면에 chemically adsorbed compounds를 desorption 시킨다. 네 번째 step은 purge 시킨다. 결과적으로 self limited 한 식각이 이루어짐을 볼 수 있었다. 실제 공정을 MOS의 high-k dielectric에 적용시켜 metal gate/high-k dielectric CMOSFETs의 NCSU (North Carolina State University) CVC model로 구한 EOT (equivalent oxide thickness)는 변화가 없으면서 mos parameter인 Ion/Ioff ratio의 증가를 볼 수 있었다. 그 원인으로 XPS (X-ray photoelectron spectroscopy)로 gate oxide의 atomic percentage의 분석 결과 식각 중 발생하는 gate oxide의 edge에 trap의 감소로 기인함을 확인할 수 있었다.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.2
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• pp.207-213
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• 2014

In this paper, we propose a modified median filter for impulse noise reduction. The proposed method based on multi-step finds noisy pixels from the corrupted image and applies filtering on the noisy pixels. Neighbor pixels for filtering are filtered by linear filter which adjusts filtering direction according to an edge. Thus, our proposed method not only preserves edge, but also reduces noise in uniform region. Experimental results show that our proposed method has better quality than those by existing modified median filtering method.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.827-828
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• 2008

Blur identification is the first and the most important step of restoring images. Edge region of the image usually conveys important information of blur parameters. In this paper we propose a region-based edge extraction method for estimating point-spread-function (PSF). As a result, the proposed method can detect the starting and the ending points of a step response, and provides the PSF parameters to the restoration process.

• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.211-214
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• 2002

Automatic video partitioning is the first step for content-based indexing and retrieval of video data. In this paper, an efficient algorithm for scene change detection is proposed, where cumulative histogram and edge information are utilized. Experimental results have shown the effectiveness of the proposed algorithm.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.33 no.7
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• pp.527-534
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• 2009

Flame stabilization characteristics were experimentally investigated in a fuel-air cross flowing mixing layer. A combustor consists of a narrow channel of air steam and a cross flowing fuel. Depending on the flow rates of methane and air, flame can be stabilized in two modes. First is an attached flame which is formulated at the backward step where the methane and air streams meet. Second is a lifted-flame which is formulated within the mixing layer far down steam from backward step. The heights and flame widths of the lifted flames were measured. Flame shapes of the lifted flames were similar to an ordinary edge flame or a tribrachial flame, and their behavior could be explained with the theories of an edge flame. With the increase of the mixing time between fuel and air, the fuel concentration gradient decreases and the flame propagation velocity increases. Thus the flame is stabilized where the flow velocity is matched to the flame propagation velocity in spite of a significant disturbance in the fuel mixing and heat loss within the channel. This study provides many experimental results for a higher fuel concentration gradient, and it can also be helpful for the development and application of a smaller combustor.