• Korean Journal of Materials Research
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• v.16 no.7
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• pp.408-411
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• 2006

An effective wet-chemical approach is demonstrated for growing large-area, selectively-patterned, and low-temperature-synthesized ZnO nanorods (ZNRs). The growth of ZNRs was enhanced on a Co layer. The selectivity and density were readily controlled by the control of the temperature when the substrate transfers into aqueous solution. The cross-sectional transmission electron microscopy image shows that single crystalline ZNRs grown along [0001] have good adhesion at interface between ZNRs/substrate. The turn-on field was 4 $V/{\mu}m$ at the emission current density of 1 ${\mu}A/cm^2$. The stable emission was obtained at 0.11 $mA/cm^2$ under 7.2 $V/{\mu}m$ over 10 hr. These results suggest that selectively-patterned ZNRs have the potential for use as field emitters in large-area field emission displays.

• Journal of the Korean Graphic Arts Communication Society
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• v.24 no.2
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• pp.11-24
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• 2006

The Lithographic ink is composed of pigment, vehicle and additives. In especially, the vehicle is the most important element and consist of vegetable oils, mineral oils and resins. Varnishes have to resist certain forms of chemical and physical attack during ink manufacturing process and printing process So this varnish cooking is very important. In this paper, effects of cooking conditions of varnish using phenolic modified rosin ester on physical properties of the vehicle were studied. The varnish cooked according to temperature and time were compared in order of average molecular weight by the GPC method. and the rheological properties were found by rotational rheometer. And the emulsion behavior were compared by high speed emulsification tester which were set on 1200 rpm and $40^{\circ}C$ temperature (Novomatics Lithotronic). We displayed viscosity against tack(Inkometer Thwing-Albert M-106) by diagram.

• Transactions on Electrical and Electronic Materials
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• v.4 no.5
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• pp.19-23
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• 2003

Time-resolved photoluminescence from InGaN/GaN multi-quantum well structures was investigated for two different shapes of square-and trapezoidal wells grown by metal-organic chemical vapor deposition. To compare to the conventional square well structure with a radiative recombination lifetime of 0.170 nsec, the large value of lifetime of 0.540 nsec from trapezoidal well were found at room temperature. This value is similar to the value for GaN host material indicating no confinement effect of quantum well. Furthermore, the high resolution transmission electron microscopy image provides the In clustering effect in the trapezoidal well structure.

• Applied Microscopy
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• v.36 no.spc1
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• pp.41-46
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• 2006

Interfacial atomic structure (chemical structure) of a Pd/ZnO hetero junction was investigated by atomic resolution high voltage transmission electron microscopy (ARHVTEM). A misfit dislocation did not work as a stress accommodation mechanism in the ZnO(0001)/Pd (111) interface. But the periodic stress localization occurred in the ZnO($10\bar{1}0$)/(200) interface. The periodicity of the local strain coincided with that of misfit dislocation. Atomic structure image of the ARHVTEM showed that an atomic arrangement across the interface was in the order of O-Zn-Pd. It was shown that mechanical weakness of the ZnO(0001)/Pd(111) interface against cyclic heating is attributable to the absence of the periodic stress localization of the misfit dislocation.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.1
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• pp.18-23
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• 2010

We demonstrated that the solution processed organic light-emitting diodes (OLEDs) have the high efficiency with pre-treated indium-tin-oxide (ITO). ITO surface was pre-treated with four methods and compared each other. The pre-treatment of ITO surface improves the chemical and physical characteristics of ITO such as the surface roughness, adhesion property, and the hole injection ability. These properties were analyzed by the contact angle, atomic force microscope (AFM) image, and the current flow character in device. As a results, the device with ITO pre-treated by $O_2$ plasma shows the current efficiency of 5.93 cd/A, which is 1.5 times the device without pre-treatment.

• Journal of Multimedia Information System
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• v.6 no.3
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• pp.155-164
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• 2019

We intended to confirm that microwave attenuation by tree leaves is strongly linked to water content in leaves. We sampled natural broadleaves, including Japanese cinnamon, and investigated their effects on the microwave (3 to 20 GHz) frequency characteristics using a network analyzer. Experiments determined that microwave attenuation by foliage increases as a linear function of frequency per unit weight (gram). As the frequency increases, the spatial resolution increases, but the phase difference (imaginary component) increases. So we solved the dispersion of phase difference by sweeping the frequency and taking the intermediate value. Based on these experimental results, we developed a microwave scanner on 10Ghz to describe foliage moisture as a image and to enable assessments of leaf condition. Photosynthesis is the process whereby plants synthesize oxygen and sugars from carbon dioxide and water, thereby converting light energy into chemical energy. Since water is a major parameter of photosynthesis, the quantity of water accumulated inside a leaf reflects leaf health. The equipment described here and related microwave technologies will help assess the capacity of leaves to absorb atmospheric carbon dioxide.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2022.06a
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• pp.1297-1300
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• 2022

Document layout analysis는 문서 이미지의 구조와 구성요소를 파악하는 기술이다. 기존 딥러닝을 사용한 학습 기반 방법에는 각 구성 요소를 검출하는 detection 기반 방식이 많으나 이는 다양한 형식의 문서 이미지에 확장될 수 있는 가능성이 낮다는 한계가 존재한다. 특히, 다양한 모양과 크기의 화학 구조를 포함하는 화학 문서 이미지에 적용하기 어렵다. 본 논문에서는 영상분할을 활용하여 화학 구조 문서를 이해하는 연구를 진행하였다. 기존의 블록 단위로 레이블링된 벤치마크와 다르게 객체 단위로 레이블링한 학습 데이터를 가지고 DeepLabv3 구조의 네트워크를 학습하여 화학 문서 이미지를 효과적으로 분할하였다. 객체 단위 레이블링과 영상 분할을 사용한 방식이 문서 이해 및 화학 구조 검출에 준수한 성능을 보이는 것을 확인하였고 이 방식이 다양한 형식의 문서 이미지에 확장될 수 있음을 보였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2023.07a
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• pp.669-670
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• 2023

본 논문에서는 열화상 카메라 및 주변 환경요인 측정 시스템을 이용하여 각종 반도체 제조공정에 사용되는 화학물질의 누수를 검출하는 방안을 제안한다. 이는 대형화되고 복잡한 집적배관이 시공되어 있는 공장 환경에서 검출센서를 통한 화학물질 누수 관리를 열화상 시스템으로 대체함으로써 보다 정확하고 안정적인 모니터링을 통해 신속한 대응 및 관리가 가능할 것이다. 또한 본 연구를 통해 누수 배관표면의 열패턴을 실시간으로 모니터링 함으로 기존 누수 검출 센서(면적식 라인타입의 센서)에 대비하여 20% 이상 검출의 신속성 향상을 보장할 수 있다.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.05a
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• pp.292-294
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• 2023

본 논문에서는 국내 사망 원인 1위 질환인 암 중 가장 큰 비중을 차지하는 폐암의 암 오진율 감소 및 정밀 진단을 위해 폐암세포를 검출 및 계수 할 수 있는 시스템을 구현하였다. 사용자가 관심 영역을 지정하면 H&E 염색 방식을 사용한 폐암세포 전처리 과정을 거쳐 검출 및 계수 할 수 있다. 본 시스템을 통해 병리학자가 단 시간에 폐암세포 검출 및 계수하여 객관적 진단 도구로 활용할 수 있으며, 디지털 기술과 융합하여 정밀 의료에 크게 기여할 수 있을 것으로 기대된다.

• Mass Spectrometry Letters
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• v.14 no.4
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• pp.121-140
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• 2023

It is becoming more and more clear that each cell, even those of the same type, has a unique identity. This sophistication and the diversity of cell types in tissue are what are pushing the necessity for spatially distributed omics at the single-cell (SC) level. Single-cell chemical assessment, which also provides considerable insight into biological, clinical, pharmacodynamic, pathological, and toxicity studies, is crucial to the investigation of cellular omics (genomics, metabolomics, etc.). Mass spectrometry (MS) as a tool to image and profile single cells and subcellular organelles facilitates novel technical expertise for biochemical and biomedical research, such as assessing the intracellular distribution of drugs and the biochemical diversity of cellular populations. It has been illustrated that ambient mass spectrometry (AMS) is a valuable tool for the rapid, straightforward, and simple analysis of cellular and sub-cellular constituents and metabolites in their native state. This short review examines the advances in ambient mass spectrometry (AMS) and ambient mass spectrometry imaging (AMSI) on single-cell analysis that have been authored in recent years. The discussion also touches on typical single-cell AMS assessments and implementations.