• Journal of Electrical Engineering and Technology
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• 제6권2호
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• pp.275-279
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• 2011

Sterilization of Escherichia coli (E. coli) is examined using a unique pulsed ultra-violet (UV) elliptical reactor based on Nd:YAG laser resonator, UV radiation from a pulsed xenon flashlamp. The light from the discharge has a broadband emission spectrum extending from the UV to the infrared region with a rich UV contained. Sterilization method by using the UV light is fast, environment-friendly and it does not cause secondary pollution. A Nd:YAG laser resonator having elliptical shape has advantage of concentrating the radiation of the UV light at two foci as the quart sleeve filled with E. coli. The primary objective of this research is to determine the important parameters such as pulse per second (pps), the applied voltage for sterilizing E. coli by using an UV elliptical reactor. From the experiment result, the sterilization effect of UV elliptical reactor is better than that of UV cylindrical reactor, and it can be 99.9% of sterilization at 800V regardless of the pps within 10 minutes.

• Journal of Electrical Engineering and Technology
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• 제8권5호
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• pp.1169-1174
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• 2013

The objective of this work was to increase the efficiency of ultraviolet-light emitting diodes at 375 nm for sterilization. Since $TiO_2$ had antibacterial properties, which were attributed to the appearance of hydroxyl radicals and superoxide radical anions on the surface species under ultra violet radiation at about 387 nm, photo-reactive layers such as Ag-doped $TiO_2$ were coated on aluminum substrates by electrostatic spraying. Crystallinity and surface morphology of the coating layer were examined by X-ray diffraction ${\theta}-2{\theta}$ scan and field emission-scanning electron microscope, respectively. In an antibacterial test, we observed above 99% reduction of Escherichia coli populations on 3 or 5 mol% Ag-doped $TiO_2$ layers after irradiation for 2 hrs at 375 nm, while very low inactivation on bare aluminum substrates occurred after irradiation as the same condition.

• Environmental Engineering Research
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• 제22권4호
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• pp.426-431
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• 2017

Some phototoxicity of titanium dioxide nanoparticles ($TiO_2$ NPs) has been reported in recent years in studies with fish embryos or larvae. However, it is necessary to focus on the potential effects of embryonic exposure due to irreversible abnormalities and mortalities observed in sac-fry, and to expand various fish embryos to generate multiple test species. The aim of this study was to evaluate the effects of $TiO_2$ NPs under different irradiation conditions in exposed Oryzias latipes (O. latipes) at the embryonic and sac-fry stages. The effects of different irradiation conditions were observed using ultra-violet (UV) and visible light, and the corresponding effects were monitored by determining cumulative mortality and abnormality. O. latipes were exposed for 8 d to 0, 1, 5, 10, or 50 mg/L $TiO_2$ NPs under UV ($4,818.86mW/m^2$ at the bottom of clear vials) or visible light, after which the embryos were transferred to NP-free embryo-rearing solution until 16 days post fertilization (dpf). Abnormalities of embryos and sac-fry increased at high $TiO_2$ NP concentrations under UV irradiation, compared to control samples treated with visible light or UV irradiation alone. This work provides information regarding the phototoxicity of $TiO_2$ NPs using O. latipes at the embryonic and sac-fry stages.

• 한국응용과학기술학회지
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• 제19권1호
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• pp.43-48
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• 2002

We carried out this subject to observe photoisomerization using 1,2-dioleoyl-sn- glycero-3-phosphocholine(DOPC) mixed with fatty acid containing azobenzene group which has reversible to cis-trans by light irradiation. Spreading solutions for the LB films were prepared in chloroform($5.0{\times}10^{-5}$mol/L).We investigated the photoisomerization and property of the organic ultra thin film of fatty acid containing azobenzene was prepared on the hydrophilic ITO(idium tin oxide) glass plate by LB method. As a result, the absorption spectra of 8A5H and DOPC of mixture LB films was induced to photoisomerization by alternating irradiation of ultraviolet and visible light, because the condensation of pure azobenzene monolayers was loosened by the introduction of phospholipid into the monolayers, and the molecular high aggregation in pure azobenzene monolayers is also weakened by the introduction of phospholipid. We found that it was reversibly induced to cis-trans photoisomerization in several solvents and mixture LB films.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 춘계학술대회 논문집 디스플레이 광소자 분야
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• pp.53-56
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• 2002

The effect of $\alpha$-septithiophene (${\alpha}-7T$) layers on the organic light emitting diode(OLED) was studied. The ${\alpha}-7T$ was used for a buffer layer in OLED. Hole injection was investigated and improved emission efficiency. The OLEDs structure can be described as indium tin oxide(ITO)/ buffer layer / hole transporting layer / emitting layer / electron transporting layer / LiF / Al. The hole transporting layer were composed of N,N-diphenyl-N,N-di(3-methylphenyl)-1,1-biphenyl-4,4-diamine(TPD), and N,N-di(naphthalene-1-ly)-N,N-diphenyl-benzidine( ${\alpha}$-NPD). The emitting layer, and electron transporting layer consist of tris(8-hydroxyquinolinato) aluminum($Alq_3$). All organic layer were deposited at a background pressure of less than $10^{-6}$ torr using ultra high vacuum (UHV) system. The ${\alpha}-7T$ layer can substitute the hole blocking layer, and improve hole injection properties.

• 한국의류산업학회지
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• 제7권1호
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• pp.111-114
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• 2005

In this the study, polyester/cotton(P/C) blended fabrics with fine denier were developed to get the light weight compared with the traditional P/C blended fabrics. Moreover, the width of the fabrics was extended by the tenter during the final heat treatment to get the lower fabric density and lighter weight. Then, the physical properties of these fabrics were analysed. The results were as the follows: The developed fabrics had 22.6-31.6% lighter weight than the traditional fabrics with the same fabric width. The weight of fabric decreased drastically with the fabrics width down to 67.1 $g/m^2$. The fabric density for the warp direction decreased with the fabric width. The tenacity and the elongation of the developed fabrics was little lower than that of the traditional fabrics. The air permeability of the developed fabrics increased with that of the traditional fabrics. The stretch rate of the developed fabrics decreased with increasing the fabric width. Residual stretch rate of the developed fabrics was more stable than that of the traditional fabrics. Residual stretch rate of the developed fabrics increased with the fabric width, but the highest value was less than 5% which is quit stable.

• 반도체디스플레이기술학회지
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• 제22권4호
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• pp.161-165
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• 2023

This paper designed a voltage feedback driving circuit to compensate for the characteristic deviation of the Active Matrix Organic Light Emitting Diode driving Thin Film Transistor. This paper describes a stable and fast circuit by applying charge sharing and polar stabilization methods. A 12-inch Organic Light Emitting Diode with a Double Wide Ultra eXtended Graphics Array resolution creates a screen distortion problem for line parasitism, and charge sharing and polar stabilization structures were applied to solve the problem. By applying Charge Sharing, all data lines are shorted at the same time and quickly positioned as the average voltage to advance the compensated change time of the gate voltage in the next operation period. A buffer circuit and a current pass circuit were added to lower the Amplifier resistance connected to the line as a polar stabilization method. The advantage of suppressing the Ringing of the driving Thin Film Transistor can be obtained by increasing the stability. As a result, a circuit was designed to supply a stable current to the Organic Light Emitting Diode even if the characteristic deviation of the driving Thin Film Transistor occurs.

• 한국항만경제학회지
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• 제33권3호
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• pp.139-154
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• 2017

국내외 항만간 경쟁이 심화됨에 따라 국내 신생 및 중소형 항만이 자체적으로 경쟁력을 확보하는데 한계가 있다. 이에 본 연구에서는 경인항을 중심으로 컨테이너 및 일반화물 물동량 5개변 60개월치의 데이터로 단기간 (12개월)의 물동량을 각각 예측하였고 중장기적으로는 어떠한 발전 방안이 필요한지 검토하였다. 첫 번째, 경인항 배후 물류단지와 연계하여 정밀기계, 홈네트워크시스템, LED, 기계공업 등의 품목을 대중국 항로로 유치하고, 두 번째, 초중량 화물 운송루트로 특화하고, 서해5도 연안섬 지역과 아라뱃길(서해5도수산물복합센터)을 연계함으로서 수산물 운반 및 여객선 준공영제를 통한 연안해운 활성화에 기여할 것으로 판단된다. 세 번째, 정부-지자체-항만의 유기적인 협력을 바탕으로 인센티브 등 선순환 지원제도가 필요하고, 마지막으로 수도권 항만의 통합운영을 통해 인근항만간 기능 조정 및 특화전략이 병행 추진되어야 할 것이다.

• 한국측량학회지
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• 제29권5호
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• pp.509-517
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• 2011

최근 일본, 뉴질랜드의 대지진과 같은 대규모 자연재해가 빈번하게 발생하고 있으며, 그 피해규모 역시 방대하다. 자연재해로 인한 긴급 상황에 효율적으로 대처하기 위해서는 재해지역의 정보를 신속 정확하게 취득하는 것이 중요하다. UAV는 낮은 고도에서 비행할 수 있고, 적은 운용비용으로 재해지역의 정보를 수집할 수 있는 효과적인 방법이다. 본 연구에서는 국내외 재해탐지용 UAV운용 관련 규정에 대한 조사 및 분석을 수행하여, 문제점을 도출하고 개선방안을 제시하고자 하였다. 재해탐지용UAV는 항공법 상 명확한 규정이 수립되어 있지 않지만 초경량비행장치로 분류할 수 있으므로 초경량비행장치에 재해탐지용UAV의 정의, 범위, 탑재장비 등의 항목이 추가되어야 할 것이다. 또한 비행허가절차로 인해 효율적인 운용이 어려운 실정이며, 이러한 문제 해결을 위한 예외 규정의 제정이 필요하다. 향후, UAV를 적용한 실제 재해탐지 사례를 바탕으로 현행 규정에 대한 분석적인 연구가 병행된다면 실시간 재해탐지 및 피해조사를 위한 체계적인 개선방안을 제시할 수 있을 것이다.

• 대한기계학회논문집A
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• 제34권9호
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• pp.1235-1240
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• 2010

와이어직조 카고메(WBK)는 나선형으로 성형된 와이어를 6 방향에서 조립하여 제작된다. 지금까지의 WBK 는 수작업으로 조립되어 왔지만, 산업적 적용을 위해서는 조립공정의 자동화가 필수적이다. 또한, 유연한 와이어로 WBK를 제작할 경우 기하학적 형상을 유지할 수 없으므로 직조기와 같은 자동화 기계의 개발이 절실하다. 이번 연구에서는, 유연한 와이어를 이용하여 WBK 를 제작하는 직조기를 설계 및 제작하였다. 이 직조기는 상부 플레이트의 회전운동과 와이어를 삽입하는 장치의 병진운동으로 작동 된다. 그리고 이미 삽입된 와이어 간의 간섭을 방지하기 위한 빗살장치는 다층의 카고메망 사이에 위치된다. 또한 이 직조기는 나선형 와이어와 직선형 와이어로 구성된 semi-WBK 의 제작에도 이용될 수 있다.