• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.12a
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• pp.82-85
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• 2003

MEMS(Micro Electro Mechanical Systems) 응용 분야에 있어서 RF나 Optic등에 응용되는 금속 구조물이나 배선을 위한 도금, 두꺼운 구조물의 식각등을 위해서 수십 um두께의 감광막이 필요하다. 특히 이러한 감광막은 도금을 위한 전단계에서 몰드 형성에 이용되는데 그 이유는 제작이 용이할 뿐만 아니라 다양한 두께 형성이 가능하고 금속과의 선택적 제거가 쉬운 장점이 있다. 감광막 몰드가 갖추어야 할 조건으로는 수직에 가까운 측면 기울기, 두께, 도금액에 대찬 저항성을 들 수 있으며 그 중에서 측면 기울기 개선에 관한 연구가 많이 진행되고 있다. 본 논문에서는 감광막의 형상에 영향을 주는 요인을 찾아내고 수식모델링을 통해 측면 기울기를 예측하고자 한다.

• Journal of the Korean School Mathematics Society
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• v.22 no.4
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• pp.351-367
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• 2019

Slope is an important mathematical concept that is connected to advanced mathematics as well as a basic concept as an indicator of the steepness of a straight line. The purpose of this study is to see how the concept of slope is presented in mathematics textbooks of middle school. For this study, we analyzed the types of slope concepts in the textbooks. In particular, we analyzed motivation activity, definition, examples of slope in them and used a concept framework of slope by Stump(1999, 2001), Moore-Russo, Connor & Rugg (2011). As a result, it was shown that middle school mathematics textbooks use the types of slope concepts to be biased when explaining the slope or presenting the slope problems. In addition, the real contexts of slope is poorly presented, and the concept types change from visual aspect to analytical aspect in the processes. This study provides suggestions on how to present the slope concepts in mathematics curriculum and middle school textbooks.

• Proceedings of the Korean Information Science Society Conference
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• 2006.10b
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• pp.464-469
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• 2006

본 논문은 연속 영상에서 빠르게 움직이거나 변형이 있는 물체를 추출하기 위한 개선된 활성 외곽선 모델을 제안한다. 제안 방법은 프레임간 물체의 변위를 식별하기 위한 합성 기울기 맵 생성 단계와 큰 변위에도 지역적 최저에 빠지지 않고 견고하게 수렴하기 위한 에너지 비탈면 생성 단계로 이루어진다. 이를 위하여 우선, 두 프레임의 기울기 맵을 합성하고, 불필요한 배경과 잡음을 제거하기 위해 두 프레임의 차를 마스크로 적용하여 합성 기울기 맵을 생성한다. 생성된 합성 기울기 맵에 수학적 형태학 연산의 하나인 닫기 연산을 적용하여 활성 외곽선이 매끄럽게 이동할 수 있는 에너지 비탈면을 만든다. 본 논문에서는 제안방법을 평가하기 위하여 움직임 변위가 큰 연속 영상을 사용하여 기존 활성 외곽선 모델 방법과 비교하여 육안평가, 에너지 최소화 과정 및 수행시간 측면에서 비교분석한다. 본 제안방법은 기존 활성 외곽선 모델 방법보다 큰 움직임 변위와 변형에도 빠르고 정확하게 물체 추적이 가능하다.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.47-48
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• 2011

PV(Photovoltaic) cell의 출력 전력은 일사량이나 온도와 같은 외부환경의 영향을 받아 변화하게 되므로 PV cell은 전압과 전력의 출력에 있어 비선형적이다. 이와 같은 비선형적 관계로 인해 MPPT(Maximum Power Point Tracking)를 수행하는 것이 PV 시스템에서는 매우 중요하다. 본 논문에서는 PV의 전력-전압 출력 특성에서 MPP를 기준으로 양쪽 경사면의 기울기와 Section의 차이를 이용한 새로운 추종법을 제안하였다. P-V 특성 곡선에서 왼쪽 측면에 비해 오른쪽 측면이 큰 기울기를 갖는 동시에 좁은 Section을 가지므로 제안하는 알고리즘은 이러한 특성을 활용한다. 또한 EMTP를 이용하여 제안된 기법의 성능과 동작을 검증하였다.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.13.1-13.1
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• 2005

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.7
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• pp.681-686
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• 2015

The onset characteristics of friction-induced noise for a steel plate and 4 metallic pins (Cu, Ni, Al, Mg) were studied through the pin-on-disk machine and the reciprocating testing machine. The results showed that the negative slope of the friction curve was related to the onset time of friction noise. Particularly, Cu was found to be the best metallic material for preventing squeak noise in terms of the onset time and the negative friction slope.

• Investigative Magnetic Resonance Imaging
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• v.18 no.1
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• pp.17-24
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• 2014

Purpose : To determine whether high-resolution contrast-enhanced three dimensional imaging with spoiled gradient-recalled sequence (HR-CE 3D-SPGR) plays a meaningful role in the assessment of intracranial vertebral artery (ICVA) and posterior inferior cerebellar artery (PICA) in lateral medullary infarction (LMI). Materials and Methods: Twenty-five patients confirmed with LMI were retrospectively enrolled with approval by the IRB of our institute, and 3T MRI with HR-CE 3D-SPGR and contrast-enhanced magnetic resonance angiography (CE-MRA) were performed. Two radiologists who were blinded to clinical information and other brain MR images including diffusion weighted image independently evaluated arterial lesions in ICVA and PICA. The demographic characteristics, the area of LMI and cerebellar involvement were analyzed and compared between patients with arterial lesion in ICVA only and patients with arterial lesions in both ICVA and PICA on HR-CE 3D-SPGR. Results: Twenty-two of twenty-five LMI patients had arterial lesions in ICVA or PICA on HR-CE 3D SPGR. However twelve arterial lesions in PICA were not shown on CE-MRA. Concurrent cerebellar involvement appeared more in LMI patients with arterial lesion in ICVA and PICA than those with arterial lesion in ICVA alone (p = 0.069). Conclusion: HR-CE 3D-SPGR can help evaluate arterial lesions in ICVA and PICA for LMI patients.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.05a
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• pp.465-468
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• 2022

The incidence of traffic accidents is increasing every year, and Korea is among the top OECD countries. In order to improve this, various road traffic laws are being implemented, and various traffic control methods using equipment such as unmanned speed cameras and traffic control cameras are being applied. However, as drivers avoid crackdowns by detecting the location of traffic control cameras in advance through navigation, a mobile crackdown system that can be cracked down is needed, and research is needed to increase the recognition rate of vehicle license plates on the side of the road for accurate crackdown. This paper proposes a method to improve the vehicle number recognition rate on the road side by applying a gradient correction algorithm using image processing. In addition, custom data learning was conducted using a CNN-based YOLO algorithm to improve character recognition accuracy. It is expected that the algorithm can be used for mobile traffic control cameras without restrictions on the installation location.

• Journal of the Semiconductor & Display Technology
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• v.3 no.1
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• pp.27-30
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• 2004

In this work, the variation of the sidewall profile of a thick photoresist on the wavelength and proximity gap was investigated. PMER P-LA900PM, DNQ (DiazoNaphthoQuinone) novolac type photoresist, is used for experiments. The calculated results agreed well with the experimental results.

• The Journal of the Korea Contents Association
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• v.3 no.4
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• pp.17-22
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• 2003

In this paper, we propose the new side-view face detection method in color images which contain faces over one. It uses color and the geometrical distance between nose and chin. We convert RGB to YCbCr color space. We extract candidate regions of face using skin color information from image. And then, the extracted regions are processed by morphological filter, and the processed regions are labeled. Also, we correct the gradient of inclined face image using projected character of nose. And we detect the inclined side-view faces that have right and left 45 tips by within via ordinate. And we get 92% detection rate in 100 test images.