• Korean Journal of Materials Research
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• v.25 no.1
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• pp.54-59
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• 2015

Glancing angle deposition (GLAD) is a powerful technique to control the morphology and microstructure of thin film prepared by physical vapor deposition. Chromium (Cr) thin films were deposited on a polymer substrate by a sputtering technique using GLAD. The change in thickness and Vickers microhardness for the samples was observed with a change in the glancing angle. The adhesion properties of the critical load (Lc) by a scratch tester for the samples were also measured with varying the glancing angle. The critical load, thickness and Vickers microhardness for the samples decreased with an increase in the glancing angle. However, the thickness of the Cr thin film prepared at a $90^{\circ}$ glancing angle showed a relatively large value of 50 % compared to that of the sample prepared at $0^{\circ}$. The results of X-ray diffraction and scanning electron microscopy demonstrated that the effect of GLAD on the microstructure of samples prepared by sputter technique was not as remarkable as the samples prepared by evaporation technique. The relatively small change in thickness and microstructure of the Cr thin film is due to the superior step-coverage properties of the sputter technique.

• Proceedings of the Optical Society of Korea Conference
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• 2005.02a
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• pp.356-357
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• 2005

• Proceedings of the Optical Society of Korea Conference
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• 2006.07a
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• pp.151-152
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• 2006

• The Korean Journal of Applied Statistics
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• v.22 no.1
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• pp.115-127
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• 2009

The purpose of statistical analyses of array-CGH experiment data is to divide the whole genome into regions of equal copy number, to quantify the copy number in each region and finally to evaluate its significance of being different from two. Several statistical procedures have been proposed which include the circular binary segmentation, and a Gaussian based local regression for detecting break points (GLAD) by estimating a piecewise constant function. We propose in this note a penalized spline regression and its simultaneous confidence band(SCB) approach to evaluate the statistical significance of regions of genetic gain/loss. The region of which the simultaneous confidence band stays above 0 or below 0 can be considered as a region of genetic gain or loss. We compare the performance of the SCB procedure with GLAD and hidden Markov model approaches through a simulation study in which the data were generated from AR(1) and AR(2) models to reflect spatial dependence of the array-CGH data in addition to the independence model. We found that the SCB method is more sensitive in detecting the low level copy number alterations.

• Proceedings of the Optical Society of Korea Conference
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• 2008.02a
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• pp.281-282
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• 2008

The glancing angle deposition (GLAD) technique was used to fabricate $ZrO_2$ thin films by electron-beam evaporation. The crystal structure, cross-sectional structure, surface morphology and optical properties are characterized by X-ray diffraction meter (XRD, Rigaku, Cu $K{\alpha}$ - radiation), scanning electron microscope (SEM), and spectrophotometer, respectively.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.335-335
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• 2011

Instability of a thin film attached to a compliant substrate often leads to emergence of exquisite wrinkle patterns with length scales that depend on the system geometry and applied stresses. However, the patterns that are created using the current techniques in polymer surface engineering, generally have low aspect ratio of undulation amplitude to wavelength, thus, limiting their application. Here, we present a novel and effective method that enables us to create wrinkles with a desired wavelength and high aspect ratio of amplitude over wavelength as large as to 2.5:1. First, we create buckle patterns with high aspect ratio of amplitude to wavelength by deposition of an amorphous carbon film on a surface of a soft polymer poly(dimethylsiloxane) (PDMS). Amorphous carbon films are used as a protective layer in structural systems and biomedical components, due to their low friction coefficient, strong wear resistance against, and high elastic modulus and hardness. The deposited carbon layer is generally under high residual compressive stresses (~1 GPa), making it susceptible to buckle delamination on a hard substrate (e.g. silicon or glass) and to wrinkle on a flexible or soft substrate. Then, we employ glancing angle deposition (GLAD) for deposition of a high aspect ratio patterns with amorphous carbon coating on a PDMS surface. Using this method, pattern amplitudes of several nm to submicron size can be achieved by varying the carbon deposition time, allowing us to harness patterned polymers substrates for variety of application. Specifically, we demonstrate a potential application of the high aspect wrinkles for changing the surface structures with low surface energy materials of amorphous carbon coatings, increasing the water wettability.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.506-507
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• 2011

경사코팅 기술(Oblique Angle Deposition; OAD)은 입사 증기가 기판에 수직으로 입사하지 않고 90도 보다 작은 각도로 비스듬히 입사하도록 조절하여 코팅하는 물리증착 기술의 하나로 피막의 조직을 다양하게 제어할 수 있는 방법으로 알려져 있다. 초기의 경사 코팅 기술은 경사각을 가진 정지된 기판 상에 코팅하였으나 최근에는 기판의 각도와 회전을 동시에 조절하여 이루어지는 소위 스침각 증착(Glancing Angle Deposition; GLAD) 기술이 개발되어 다양한 형태의 구조를 제어하는 연구가 활발히 진행되고 있다. 특히, 컴퓨터를 이용하여 입사각과 방위각을 정밀 제어함에 의해 나노 스케일의 Zigzag 및 나선형, 기둥형 조직 등 복잡한 형태의 박막을 제조하는 것이 가능하게 되었다. 현재, GLAD 기술과 다양한 형태의 나노 조직을 이용하여 각종 센서는 물론 태양전지와 같은 에너지 소자, 필터와 같은 광학코팅 등에 응용하기 위한 연구가 세계적으로 폭넓게 진행되고 있다. 본 연구에서는 조직의 치밀도 향상을 통한 특성 향상을 위해 Al 및 TiN 박막을 제조함에 있어서 경사코팅 기술을 응용하여 단층 및 다층 피막(각도를 반대로 하여 여러 층을 제조)을 제조하고 그 특성을 비교하였다. Al 박막은 UBM (Un-Balanced Magnetron) 스퍼터링 소스를 이용하여 타겟 표면과 기판 표면이 이루는 각도 즉, 입사빔과 기판이 이루는 각도를 각각 0, 30, 45, 60 및 90도의 각도에서 강판 및 실리콘 웨이퍼 상에 시편을 제조하되 단층 및 다층으로 시편을 제조하고 치밀도 및 내식성과 반사율 및 조도 등의 특성을 비교하였다. 그 결과 경사각으로 코팅한 시편에서 조도 및 반사율이 향상됨은 물론 치밀도 및 내식성이 향상됨을 확인하였다. 특히, 염수분무에 의한 내식성 시험에서 경사 코팅된 시편의 경우 내식성이 현저히 향상되었는데, 이는 경사 코팅 방법이 박막의 치밀도를 향상시켜 나타난 현상으로 판단된다. TiN 박막은 Cathodic Arc 방식을 이용하되 Al 박막과 동일한 방법으로 코팅을 하고 내식성 및 경도 등의 특성을 비교하였다. TiN 박막은 경사각이 커지면서 경도가 낮아지며 특히 다층막의 경우 경도 감소가 현저함을 알 수 있었다. 다만, 45도에서는 다른 경사각에 비해 약간의 경도 상승이 측정되었다. 경사각 코팅에서의 경도 감소는 피막의 경사에 의해 탐침이 미끄러지거나 또는 우선 방위에 의한 경도 증가 효과가 나타나지 않아 생기는 현상으로 판단되었다. Ferroxyl 시험을 이용한 기공도 시험에서는 경사각 코팅의 경우가 기공이 다소 감소함을 확인하였다.

• Clinics in Shoulder and Elbow
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• v.14 no.1
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• pp.20-26
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• 2011

Purpose: The purpose of this study is to investigate the accompanying lesions of humerus greater tuberosity fracture with anterior shoulder dislocation and to analyze its clinical results. Materials and Methods: From May 2005 to November 2008, arthroscopy was performed on a total of 30 selected patients who were diagnosed with humerus greater tuberosity fracture with anterior shoulder dislocation and who were also under the age of 40. The preoperative and postoperative Constant and Rowe scores were compared. Results: There was a total of 21 cases of anteroinferior labral lesions: 2 Bankart lesions, 4 bony Bankart lesions, 4 Perthes lesions, 2 free ALPSA lesions, 3 GLAD lesions and 6 capsular tears. For other lesions, 5 rotator cuff partial tears, 3 SLAP lesions and 1 biceps tendon rupture were found. The constant scores were increased from 56.3 to 94.43 points (p=0.034), and the Rowe scores were increased from 52.56 to 91.76 points (p=0.026). Conclusion: For humerus greater tuberosity fracture with anterior shoulder dislocation, the accompanying lesion was identified and the fracture was treated using arthroscopy. Good clinical results and bone union were achieved. According to the secondary arthroscopic findings, all of the Perthes lesion, the free ALPSA lesion, the GLAD lesion and the capsular tear spontaneously healed or they did not progress to extended rupture although arthroscopic suture was not performed. Any postoperative secondary instability was not observed.

• Journal of the Korean Professional Engineers Association
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• v.36 no.6
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• pp.36-40
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• 2003

We Professional Engineers in Japan and Korea have decided to introduce the theme of 2003's convention after two bilateral talks. So we will discuss on the near future in the Northeast Asia. I will make a speech based on this concept. I am very glad to talk to everybody here. I have been participating in this congress, since 1985 and I have made friends with Korean PE s. I hope that I attend the congress until may age of 84 when the 50th congress would be held. The speech is based on my experience and I will speak frankly So, I was born In Seoul and brought up in Pusan on my childhood but I only understand "Hello everybody" "Thank you" "How much" "No problem" "I love you" in your own language. Fortunately Mr Chung Byung Sook helps me to make myself understood in Korean as a translator. Thank you.

• Journal of the Korean Institute of Telematics and Electronics
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• v.20 no.5
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• pp.16-22
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• 1983

Liquid crystal matrix display is fabricated. ITO transparent electrode and silver paste metal electrode are coated on glad substrate using silk screen printing technique, and SiO is coated on the transparent electrode by evaporation. Liquid crystal molecules are aligled by rubbing technique and displays of Alphanumeric and Hangul are tried using the dynamic scattering effect and the 3: 1 selection method.