• Transactions on Electrical and Electronic Materials
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• 제9권2호
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• pp.52-56
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• 2008

Carbon nanotube films were fabricated by the catalytic CVD method. Plasma processed time effects on the field emission property were studied. The atomic structure was observed by using X-ray photoelectron spectroscopy (XPS). The surface composition changes were observed on the plasma processed CNT films. The O1s/C1s signal ratio and the Fls/Cls signal ratio changed from 1.1 % to 24.65 % and from 0 % to 3.1 % with plasma process time, respectively. We could guess it from these results that the Ar plasma process could change the surface composition effectively. In the case of the original-CNT film, no carbon shift was observed. In the case of the Ar plasma processed CNT films, however the oxygen related carbon shifts were observed. This oxygen related carbon shift at higher binding energy implies the increment of amount of the oxygen. It's possible that the increment of these bonds between carbon and oxygen results in the improvement of field emission performance.

• Transactions on Electrical and Electronic Materials
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• 제15권1호
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• pp.32-36
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• 2014

In this study, the etching characteristics of titanium dioxide ($TiO_2$) thin films were investigated with the addition of $N_2$ to CF4/Ar plasma. The crystal structure of the $TiO_2$ was amorphous. A maximum etch rate of 111.7 nm/min and selectivity of 0.37 were obtained in an $N_2/CF_4/Ar$ (= 6:16:4 sccm) gas mixture. The RF power was maintained at 700 W, the DC-bias voltage was - 150 V, and the process pressure was 2 Pa. In addition, the etch rate was measured as functions of the etching parameters, such as the gas mixture, RF power, DC-bias voltage, and process pressure. We used X-ray photoelectron spectroscopy to investigate the chemical state on the surface of the etched $TiO_2$ thin films. To determine the re-deposition and reorganization of residues on the surface, atomic force microscopy was used to examine the surface morphology and roughness of $TiO_2$ thin films.

• 디지털융복합연구
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• 제16권9호
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• pp.413-419
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• 2018

스마트폰은 현대사회에서 꼭 필요한 통신수단이 되었고 이미 인류의 일상생활에 융합되었다. 만약에 미니 헤드 마운트 표시 장치(HMD)를 활용하여 증강현실 기술로 통신 중인 양쪽 상대방의 용모, 표정, 동작 등의 요소가 통화 환경에 들어오면 사용하는 사람에게 직관적이고 특별한 느낌을 준다. 그리고 이 방식으로 시각의 한계성을 넘어설 수 있으므로 미래 시각예술 영역의 크게 발전을 촉진할 수 있어서 이런 기술적인 문제에 관한 연구의 의미가 있다. 본 논문은 효과적인 AR 영상통화 구현 방법에 대한 현재 사용되는 기술 중 몇 가지를 융복합하여 실현 가능한 두 가지 가설방안을 세우고 분석과 비교하여 두 가지 가설방안의 문제점을 발견한다. 그리고 문제점에 대한 해결 가능한 디자인 방안을 꺼낸다. 또 사례연구의 방식으로 실제 사례를 제출하여 두 가지 가설 방안은 미래에 실현 가능하다는 결론을 검증한다. 이러한 기술들은 우리의 일상에 더욱 재미요소와 편리함을 제공할 것이라 예상된다. AR 영상통화를 순조롭게 구현하는 것은 예견할 수 있고 나중에 무한한 발전 가능성이 있다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권8호
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• pp.438-444
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• 2000

We report the effects of etch process parameters on the ohmic contact formation in the plasma etching of GaN. Planar inductively coupled plasma system with $CH_4/H_2/Ar$gas chemistry has been used as etch reactor. The contact resistance and the specific contact resistance have been investigated using transfer length method as a function of RF bias power and %Ar gas concentration in total flow rate. AES(Auger electron spectroscopy) analysis revealed that the etched GaN has nonstoichiometric Ga rich surface and was contaminated by carbon and oxygen. Especially large amount of carbon was detected at the sample etched for high bias power (or voltage) condition, where severe degradation of contact resistance was occurred. We achieved the low ohmic contact of $2.4{\times}10^{-3} {\Omega}cm^2$ specific contact resistance at the input power 400 W, RF bias power 150 W, and working pressure 10mTorr with 10 sccm $CH_4$, 15 sccm H2, 5 sccm Ar gas composition.

• 대한본초학회지
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• 제31권3호
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• pp.13-22
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• 2016

Objectives： Arachidonic acid is control the thromboxane A2 (TXA2) and prostacycline (PGI2) synthesis, TXA2 increase lead to thrombus produced by induces platelet aggregation and vasoconstriction. Angelicae gigantis radix (RAR) is mainly used blood deficiency and stagnation. In previous studies, RAR has been reported that a vasodilating and blood clotting delay effects. In this study, investigate that anti-oxidant and anti-thrombotic effects of RAR by heat-process.Methods： The heated angelicae gigantis radix sample were made by 140, 180, and 220 ℃ and 4, 6, 9 and 12 min using water or 30% ethanol. The anti-oxidant effects were measured by total polyphenol, total flavonoid, DPPH and ABTS radical scavening activation. Anti-thrombotic effect conducted in samples that are determined to be effective through the anti-oxidant experiment such as angelicae gigantis radix roasted 180℃, and 220℃ and angelicae gigantis radix roasted with 30% ethanol 180℃, and 220℃.Results： Anti-oxidant parameters were efficacious in high temperature roasted AR. Also AR and EAR increased a inhibitory activity of FXa compared with RAR. The blood coagulation time of administration groups were significantly increased compare with control group. The TXB2 was significantly decreased in AR and EAR.Conclusions : We confirmed that whether AR and EAR administration has anti-oxidant and anti-thrombotic effect or not. As the results, AR and EAR were improved anti-oxidant effects and blood biochemistry compare with control group. This study provides scientific evidence that AR and EAR are have an anti-oxidant effect and anti-thrombotic effect, it expected that there is no difference between the two.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.77-77
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• 2011

These days, a growing demand for memory device is filled up with the flash memory and the dynamic random access memory (DRAM). Although DRAM is a reasonable solution for current demand, the universal novel memory with high density, high speed and nonvolatility, needs to be developed. Among various new memories, the magnetic random access memory (MRAM) device is considered as one of good candidate memories because of excellent features including high density, high speed, low operating power and nonvolatility. The etching of MTJ stack which is composed of magnetic materials and insulator such as MgO is one of the vital process for MRAM. Recently, MgO has attracted great interest in the MTJ stack as tunneling barrier layer for its high tunneling magnetoresistance values. For the successful realization of high density MRAM, the etching process of MgO thin films should be investigated. Until now, there were some works devoted to the investigations on etch characteristics of MgO thin films. Initially, ion milling was applied to the etching of MgO thin films. However, ion milling has many disadvantages such as sidewall redeposition and etching damage. High density plasma etching containing the magnetically enhanced reactive ion etching and high density reactive ion etching have been employed for the improvement of etching process. In this work, inductively coupled plasma reactive ion etching (ICPRIE) system was adopted for the improvement of etching process using MgO thin films and etching gas mixes of $CH_4$/Ar and $CH_4$/$O_2$/Ar have been employed. The etch rates are measured by a surface profilometer and etch profiles are observed using field emission scanning emission microscopy (FESEM). The effects of gas concentration and etch parameters such as coil rf power, dc-bias voltage to substrate, and gas pressure on etch characteristics will be systematically explored.

• Spatial Information Research
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• 제22권2호
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• pp.1-9
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• 2014

UN-REDD/AR-CDM이 산림파괴로 인한 이산화탄소 배출을 줄이기 위한 중요한 제도로 국제사회에서 부상되고 있다. 북한의 산림 파괴를 막는 동시에 남한의 탄소배출권 확보라는 측면에서 북한 지역을 UN-REDD/AR-CDM 사업대상지로 등록하고자 하는 논의가 지속되고 있다. 백두산의 산림은 황폐화되어 있는 지역과 거대한 숲의 바다를 이루고 있는 지역이 혼재하고 있어 UN-REDD과 AR-CDM의 등록대상이 될 수 있는 것으로 확인된다. 따라서 본 연구의 목적은 기존의 REDD와 AR-CDM의 개별 등록방식에서 탈피하여 소유역별 탄소저장량 변화추세에 의거 UN-REDD와 AR-CDM 등록가능성을 모색하는 데 있다. 소유역별로 AR-CDM/REDD을 동시에 적용할 경우 AR-CDM 단일 방식 보다 21.9%, REDD 단일방식보다 53.2% 높은 탄소저장량을 나타내었다. 본 연구의 결과는 소유역별 탄소저장량 변화특성에 의거 UN-REDD나 AR-CDM을 선택하여 등록여부를 검토하는 과정에서 중요한 참고자료로 활용될 수 있을 것이다.

• 한국건설관리학회논문집
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• 제18권2호
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• pp.21-29
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• 2017

최근 증강현실(AR)에 대한 대중적인 관심의 증가와 함께, 건설장비에 AR 기술을 도입하여 효율성을 높이려는 다수의 연구가 진행되고 있다. AR 기술을 도입하기 위해선 실세계와 카메라의 가상세계를 오차없이 연결할 수 있는 정교한 외부 표정이 필수적이다. 하지만 건설 현장에서는 한정된 비용과 시간의 문제와 현재 상용화되어있는 야외용 트래킹 시스템(경사계, GPS시스템 등의 오차로 인해, 정교한 외부 표정을 도입하는 것이 사실상 불가능하다. 본 연구에서는 굴삭기에 적용되는 AR 시스템인 AR 네비게이터를 위하여 정교하지 않은 외부 표정을 이용하더라도 이미지 프로세싱 기법을 통해 가상 이미지를 매끄럽게(Seamless) 중첩시키는 방법을 제안한다. 본 연구를 기반으로, 건설장비에 특화된 AR 네비게이터의 개발을 완료할 수 있을 것이라 생각이 된다. 또한 개발된 AR 네비게이터를 건설현장에 보급함으로써, 건설현장의 작업 효율성과 크게 향상시킬 것이라 기대하고, 추후 굴삭기 뿐 아니라 다른 건설장비에 적용될 수 있는 AR 기반 시스템이 갖춰질 것이라 생각한다.

• Progress in Superconductivity
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• 제14권2호
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• pp.116-121
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• 2012

Effect of mixed gas and additional Mg powder in an annealing process of the $MgB_2$ is investigated. Four different type of samples were prepared, each in different annealing environment of Ar, $Ar+4%H_2$, Ar with Mg powder and $Ar+4%H_2$ with Mg powder. Different annealing environment did not affect the electron-phonon interaction which is reflected from the same superconducting transition of 36.6 K for all samples. The reducing effect of hydrogen is clearly depicted from the presence of excess Mg in sample synthesized in $Ar+4%H_2$ gas implying the reduced rate of reaction between Mg and B. This has manifested itself in terms of slightly increased high-field critical current density of the sample. In contrast, the sample synthesized in $Ar+4%H_2$ with Mg powder, has shown overall enhancement in the superconducting properties as presented by higher diamagnetic saturation and critical current density.

• 반도체디스플레이기술학회지
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• 제6권4호
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• pp.11-15
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• 2007

As preparing electrode for the OLED with the sputtering process, in order to be lower damage of the bottom organic layer and increase the life-time of the OLED, we prepared Al electrode for that by using Facing Targets Sputtering (FTS) system. Al electrode directly deposited on the cell (LiF/EML/HTL/Bottom electrode). Deposition condition was the working gas (Ar, Kr and Ar+Kr) and working gas pressure (1 and 6 mTorr). The film thickness and I-V curve of Al/cell were evaluated by a $\acute{a}$-step profiler and a semiconductor parameter (HP4156A) measurement. The thin film surface image was observed by a Atomic Force Microscope (AFM). In result, in comparison with about 11 [V] of the turn-on voltage of Al/cell with using the pure Ar gas, when Al thin film was deposited using the Ar-Kr mixture gas, the surface morphology was improved in some region and the turn-on voltage of Al/cell could be decreased to about 7 [V].