• Nuclear Engineering and Technology
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• 제53권4호
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• pp.1259-1265
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• 2021

In the present study, a large-area hybrid gamma imaging system was designed by adopting coded aperture imaging on the basis of a large-area Compton camera to achieve high imaging performance throughout a broad energy range (100-2000 keV). The system consisting of a tungsten coded aperture mask and monolithic NaI(Tl) scintillation detectors was designed through a series of Geant4 Monte Carlo radiation transport simulations, in consideration of both imaging sensitivity and imaging resolution. Then, the performance of the system was predicted by Geant4 Monte Carlo simulations for point sources under various conditions. Our simulation results show that the system provides very high imaging sensitivity (i.e., low values for minimum detectable activity, MDA), thus allowing for imaging of low-activity sources at distances impossible with coded aperture imaging or Compton imaging alone. In addition, the imaging resolution of the system was found to be high (i.e., around 6°) over the broad energy range of 59.5-1330 keV.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2023년도 추계학술발표대회
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• pp.678-680
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• 2023

본 연구는 2022년 유네스코 인류무형유산 대표목록에 등재된 탈춤 동작을 디지털화하여 후속 세대에게 정보를 제공하는 것을 목적으로 한다. 데이터 수집은 국가무형문화제로 지정된 탈춤 단체 13개, 시도무형문화재 단체 5개에 소속된 무형문화재, 전승자 39명이 관성식 모션 캡처 장비를 착용하고, 8대의 카메라를 이용하여 수집하였다. 데이터 가공은 바운딩박스를 수행하였고, 탈춤동작 추정은 YOLO v8을 사용하였고 탈춤 동작 분류는 YOLO v8에 CNN모델을 결합하여 130개의 탈춤을 분류하였다. 연구결과, mAP-50은 0.953, mAP50-95는 0.596, Accuracy 70%를 달성하였다. 향후 학습용 데이터셋 구축량이 늘어나고, 데이터 품질이 개선된다면 탈춤 분류 성능은 더욱 개선될 것이라 기대한다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.881-884
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• 2004

The robust and large-area applicable metal shadow masks with a high aspect ratio more than 20 are fabricated by a combination of micro-electro-discharge machining (${\mu}$-EDM) and electro chemical etching (ECE). After defining S/D contacts using a 100 ${\mu}m$ thick stainless steel shadow mask, the top-contact pentacene TFTs with channel length of 5 ${\mu}m$ showed routinely the results of mobility of 0.498 ${\pm}$ 0.05 $cm^2$/Vsec, current on/off ratio of 1.6 ${times}$ $10^5$, and threshold voltage of 0 V. The straightly defined atomic force microscopy (AFM) images of channel area demonstrated that shadow effects caused by the S/D electrode deposition were negligible. The fabricated pentacene TFTs have an average channel length of 5 ${\pm}$ 0.25 ${\mu}m$.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.88-89
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• 2009

In this paper, we investigated about wet cleaning effect as deep trench formation methods for Power chip devices. Deep trench structure was classified by two methods, PSU (Poly Stick Up) and Non-PSU structure. In this paper, we could remove residue defect during wet. cleaning after deep trench etch process for non-PSU structure device as to change wet cleaning process condition. V-SEM result showed void image at the trench bottom site due to residue defect and residue component was oxide by EDS analysis. In order to find the reason of happening residue defect, we experimented about various process conditions. So, defect source was that oxide film was re-deposited at trench bottom by changed to hydrophobic property at substrate during hard mask removal process. Therefore, in order to removal residue defect, we added in-situ SCI during hard mask removal process, and defect was removed perfectly. And WLR (Wafer Level Reliability) test result was no difference between normal and optimized process condition.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.347-347
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• 2009

결정질 태양전지의 공정에 있어서 호모지니어스(homogeneous)한 구조보다 향상된 변환효율을 얻기 위해 선택적 도핑 방법에 관한 연구가 활발하다. 선택적 도핑 방법이란 에미터(emitter) 층을 $n^{++}$ 영역과 $n^+$ 영역으로 나누어 향상된 전류밀도와 개방전압을 얻기 위한 방법이다. 본 연구에서 제시된 RIE 에치-백 구조는 다수의 선택적 도핑 방법 중 하나이다. 기존의 에치-백 구조는 전면 전극 형성 후 RIE 공정을 수행하기 때문에 전면 전극이 손상되고 RIE 데미지(damage)가 발생되는 문제점이 있었다. 그러나 본 연구에서 제시된 구조는 기존의 에치-백 구조와 달리 RIE 에칭 후 발생된 데미지를 제거하는 추가적인 공정인 질산 패시베이션(nitric acid passivation)이 수행되었다. 또한 본 연구에서 새롭게 제시된 블라킹 마스크 페이스트(blocking mask paste)는 기존의 에치-백 구조에서 발생된 전극 손상 문제를 해결해 주고 있다. 이러한 결과로 호모지니어스 구조보다 향상된 전류밀도 (35.77 mA/$cm^2$), 개방전압 (625 mV), FF (78.01%), 변환효율 (17.43%)를 얻었다.

• 한국세라믹학회지
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• 제34권10호
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• pp.1021-1026
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• 1997

RuO2 thin film has reasonably good conductivity and stiffness and it is thought to substitute for the cantilever beam made up of Pt and Si3N4 double layers in microactuators. Therefore, anisotopic Si etching was performed using RuO2 thin film as a mask layer in 25 wt. % TMAH water solution. In the etching temperature ranging from 6$0^{\circ}C$ to 75$^{\circ}C$, the etch rates of all the crystallographic directions increased linearly as the etching temperature increased. The etch rate ratio(selectivity) of [111]/[100] which varied from 0.08 to 0.14, was not sensitive to temperature. The activation energies for [110] direction, [100] direction and [111] direction were 0.50, 0.66 and 1.04eV, respectively. RuO2 cantilever beam with a clean surface was formed at the etching temperatures of 6$0^{\circ}C$ and $65^{\circ}C$. But the damages due to formation of pin holes on RuO2 surface were observed beyond 7$0^{\circ}C$. The tensile stress of RuO2 thin films caused the cantilever bending upward. As a result, it was demonstrated that the formation of conducting oxide RuO2 cantilever beam which can replace the role of an electrode and supporting layer could be possible by TMAH solution.

• 산경연구논집
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• 제14권5호
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• pp.31-39
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• 2023

Purpose: As SARS-CoV-2, which was the main cause of the global pandemic, has repeatedly mutated in various forms, the threat of the virus has decreased considerably, and the spread has also subsided. Therefore, the purpose of this study was to explore the change in the role of masks and sustainable mask consumption according to the change in perception of wearing masks during the pandemic. Research design, data and methodology: This study used a descriptive review method as a literature review, and utilized the literature search method in PubMed, Riss, Scopus, and Google Scholar databases. Among them, a total of 46 papers were selected in the final stage. Results: As a result, it can be seen that during the pandemic, masks changed their roles according to social trends as their perceptions changed from general perceptions of protecting from external environments or diseases to fashion items with quarantine functions. Conclusions: Masks will be continuously consumed as one of the fashion items with the function of quarantine that protects the respiratory tract from the external environment that is indispensable in our daily lives. Therefore, measures should be taken on sustainable consumption measures according to consumer demand for disposable masks.

• 정보처리학회 논문지
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• 제13권7호
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• pp.335-347
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• 2024

개방형 어휘 3차원 포인트 클라우드 개체 분할은 3차원 장면 포인트 클라우드를 훈련단계에서 등장하였던 기본 클래스의 개체들뿐만 아니라 새로운 신규 클래스의 개체들로도 분할해야 하는 어려운 시각적 작업이다. 본 논문에서는 중요한 모델 설계 이슈별 기존 모델들의 한계점들을 극복하기 위해, 새로운 개방형 어휘 3차원 개체 분할 모델인 Open3DME를 제안한다. 첫째, 제안 모델은 클래스-독립적인 3차원 마스크의 품질을 향상시키기 위해, 새로운 트랜스포머 기반 3차원 포인트 클라우드 개체 분할 모델인 T3DIS[6]를 마스크 제안 모듈로 채용한다. 둘째, 제안 모델은 각 포인트 세그먼트별로 텍스트와 의미적으로 정렬된 시각적 특징을 얻기 위해, 사전 학습된 OpenScene 인코더와 CLIP 인코더를 적용하여 포인트 클라우드와 멀티-뷰 RGB 영상들로부터 각각 3차원 및 2차원 특징들을 추출한다. 마지막으로, 제안 모델은 개방형 어휘 레이블 할당 과정동안 각 포인트 클라우드 세그먼트별로 추출한 2차원 시각적 특징과 3차원 시각적 특징을 상호 보완적으로 함께 이용하기 위해, 특징 앙상블 기법을 적용한다. 본 논문에서는 ScanNet-V2 벤치마크 데이터 집합을 이용한 다양한 정량적, 정성적 실험들을 통해, 제안 모델의 성능 우수성을 입증한다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1995년도 추계학술대회 논문집
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• pp.351-356
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• 1995

A optical switch which on the LiNbO$_3$substrate is fabricated by using proton exchange method and self-alignet method. The annealing at 400[$^{\circ}C$] was carried out to control waveguide width and depth. A self-aligned method, which doesn\`t need the additional mask precesses, was applied to simplify the fabrication processes and to maximize efficiency of electric field application. The depths of the two annealed optical waveguides, which were measured by using ${\alpha}$-step, ware 1.435[K${\AA}$] and 1,380[K${\AA}$]. Using ${\alpha}$-step facility, we examined that the width of waveguides is increased from 5[$\mu\textrm{m}$] to 6.45[$\mu\textrm{m}$] and 6.3[$\mu\textrm{m}$] due to the annealing effects. The process of proton exchange was done at 400[$^{\circ}C$] for 60[min] and annealing process was done at 400[$^{\circ}C$] for 60[min]. The high speed optical modulator has very good figures of merits: the measured voltage of the input waveguide power is 3.5[V], the voltage of the coupling waveguide power is 3.9[mV], and -29.5[dB] crosstalk and 8[V] switching voltage were achieved.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1466-1469
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• 2008

We have fabricated 2.5 inch QQCIF AM-OLED panel driven by ZnO-TFT on a plastic substrate for the first time. The number of photo mask for the whole panel process was 5 and the TFT structure was top gate with active protection layer as a first gate insulator. Optimizing the process for the substrate buffer layer, active layer, ZnO protection layer, and gate insulator was key factor to achieve the TFT performance enough to drive OLED. The ZnO TFT has mobility of $5.4\;cm^2/V.s$, turn on voltage of -6.8 V, sub-threshold swing of 0.39 V/decade, and on/off ratio of $1.7{\times}10^9$. Although whole process temperature is below $150^{\circ}C$ to be suitable for the plastic substrate, performance of ZnO TFT was comparable to that fabricated at higher temperature on the glass.