• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.24-27
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• 2009

A hybrid model has been developed which adopts a fluid model for electrons and a particle-in-cell (PIC) model for ions. Using the hybrid simulation, the discharge characteristics are investigated with the diagnostics for the electric field and the wall charge profile, density distributions of charged and excited particles, distributions of ultraviolet lights on phosphor, and the visible lights emitted from the PDP cell. Also, energy and angle distributions of the ions at the MgO protective layer are obtained for the analysis of material effect. The comparison of hybrid simulation results with experimental results as well as that with the conventional fluid simulation shows that the new model is more adequate for the simulation of PDP cells.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.121-124
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• 2006

A novel quantum chemical molecular dynamics program, 'Colors' was developed to simulate the electronic structure of rare earth-doped phosphor materials as well as the destruction processes of MgO protecting layer in plasma display panel (PDP). We have also developed a quantitative prediction method based on Monte Carlo simulation technique to evaluate the electrical conductivity of insulators, semiconductors, and metals as well as the spatial distribution of electron density by Colors code. All these original simulators enable us to study theoretically a variety of materials related to PDP.

• Transactions on Electrical and Electronic Materials
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• 제3권1호
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• pp.4-8
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• 2002

The typical mold method for FED (field emission display) fabrication is used to form a gate electrode, a gate oxide layer, and emitter tip after fabrication of a mold shape using wet-etching of Si substrate. However, in this study, new mold method using a side wall space structure was developed to make sharp emitter tips with the gate electrode. In new method, gate oxide layer and gate electrode layer were deposited on a Si wafer by LPCVD (low pressure chemical vapor deposition), and then BPSG (Boro phosphor silicate glass) thin film was deposited. After then, the BPSG thin film was flowed into the mold at high temperature in order to form a sharp mold structure. TiN was deposited as an emitter tip on it. The unfinished device was bonded to a glass substrate by anodic bonding techniques. The Si wafer was etched from backside by KOH-deionized water solution. Finally, the sharp field emitter array with gate electrode on the glass substrate was formed.

• Nuclear Engineering and Technology
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• 제34권2호
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• pp.142-145
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• 2002

CaSO$_4$:Dy thermoluminescence dosimeter (TLD) is widely used as a personal or environmental dosimeter because of its high sensitivity to radiation. There are many methods to make pellets from the TL phosphorss[l-5]. Sintered pellets were made from a mixture of CaSO$_4$:Dy phosphor and Teflon powder is the most common method. But this method has disadvantage that CaSO$_4$:Dy pellet does not have very high sensitivity because of large amounts of Teflon in Pellets. This Paper described development of a new type of CaSO$_4$:Dy pellets by using P- compounds as a bonding material (KCT-300), and compared the TL sensitivity with that of the commercialized Teledyne CaSO$_4$: Dy pellets. Sensitivity of a new developed KCT-300 shows about 6 times than Teledyne ones, and can be used to measure very low radiation dose.

• 공학기술논문지
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• 제6권2호
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• pp.121-124
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• 2013

This paper proposed a new concept of estimating method for LED(light-emitting diode) delamination with high accuracy. Usually, The LED is composed several materials which are LED chips, gold wire, phosphor, epoxy resin, adhesive, reflector and lead frame. These different materials are usually delaminated in a trouble conditions which are huge temperature difference, hot and humid or mechanical shocked. When the components are delaminated, a luminance will be lost, moisture be absorbed easily and a thermal resistance be increased attendantly. As a conventional method to estimate a delamination of LEDs, a solution immersing method is usually used in a field of LED manufacturing companies or researching institutes. This method has an advantage of simplicity but it is only shown that the existence of delamination or not. In this paper, we have proposed an estimating method for LEDs delamination using the polishing and the electron microscope. New proposed method has shown the result of confirming delamination without destruction and enabled quantitative analysis for LED delamination.

• 생명과학회지
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• 제27권3호
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• pp.370-381
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• 2017

단백질 탈 인산화는 단백질 탈 인산화 효소에 의해 매개되는 과정으로 세포 생존에 매우 중요하다. 단백질 탈 인산화 효소 중에서 최근 CTD (carboxy-terminal domain) 탈 인산화 효소들이 등장하고 있으며 이들에 대한 새로운 생물학적 역할이 밝혀지고 있다. 이 효소의 그룹에는CTD 탈 인산화 효소 1(CTDP1), CTD 소형 탈 인산화 효소 1(CTDSP1), CTD 소형 탈 인산화 효소 2(CTDSP2), CTD 소형 탈 인산화 효소 유사(CTDSPL), CTD 소형 탈 인산화 효소 유사 2(CTDSPL2), CTD 핵 탈 인산화 효소(CTDNEP1) 및 유비퀴틴 유사 도메인 함유CTD 탈 인산화 효소 1(UBLCP1)들이 존재한다. CTDP1은 RNA 중합 효소 II (RNAPII)의 CTD의 두 번째 인산화 된 세린을 탈 인산화 시키고, CTDSP1, STDSP2 및 CTDSPL은 RNAPII의 CTD의 다섯 번째 인산화 된 세린을 탈 인산화 시킨다. 그리고 CTDSP1은 SMAD들, CDCA3, Twist1, 종양억제 단백질인 PML, c-Myc과 같은 새로운 기질을 탈 인산화 시키는 것으로 밝혀지고 있다. CTDP1은 유사 분열 조절 및 암세포 성장과 관련이 있다. CTDSP1, CTDSP2 및 CTDSPL은 종양 억제 기능 및 줄기 세포 분화와 관련이 있다. CTDNEP1은 LIPIN1을 탈 인산화 시키고 핵막 형성과 관련이 있다. CTDSPL2는 조혈 줄기 세포 분화와 관련이 있다. UBLCP1은 26S 프로테아좀을 탈 인산화 시키고 핵 프로테아좀 활성 조절과 관련이 있다. 결론적으로, CTD 탈 인산화 효소의 새로운 기능과 역할은 최근의 연구에서 밝혀지고 있으며, 이 리뷰는 CTD 탈 인산화 효소의 새롭게 밝혀진 역할들을 요약하고자 정리한 것이다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.441-443
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• 2005

According as CCFL(Cold Cathode Fluorescent lamp) of light source in Backlight unit for Note PC (Personal computer) is presently needed to low power consumption and long life time, the development focus of CCFL is going on the discharge gas, phosphor and electrode material. First of all, discharge voltage characteristic of CCFL is closely connected with electrode material For low discharge voltage, the characteristic of electrode material is needed to low work function, low sputtering ratio and superior manufacturing property. We developed new CCFL with Nb/Ni Clad electrode superior to conventional CCFL. Because Nb/Ni Clad electrode with Ni material and Nb material, the electrical characteristic is superior to other electrode materials. The electrode of Nb/Ni Clad is composed that Ni of outside material has superior manufacturing property and Nb of inside material has low work function. Nb/Ni Clad of new electrode material is made by process of Rolling mill at high pressure and heat treatment. We compared electrical characteristic of Nb/Ni clad electrode with conventional Mo electrode by measurement. Mo electrode and Nb/Ni Clad electrode of cup type with diameter 1.1 mm and length 3.0mm are used to this experiment. Material content of Mo electrode is Mo 100%. But, Nb/Ni Clad electrode is composed by content of Nb 40% and Ni 60%. The result of comparison measurement between new CCFL with Nb/Ni Clad electrode and conventional CCFL was appeared that CCFL with Nb/Ni Clad electrode had superior characteristic than conventional CCFL. As a result of experiment, we completed Note PC with low power consumption and long life time by application of new CCFL with Nb/Ni Clad electrode.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2012년도 제43회 하계 정기 학술대회 초록집
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• pp.86-86
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• 2012

The new approaches for silicon solar cell of new concept have been actively conducted. Especially, solar cells with wire array structured radial p-n junctions has attracted considerable attention due to the unique advantages of orthogonalizing the direction of light absorption and charge separation while allowing for improved light scattering and trapping. One-dimenstional semiconductor nano/micro structures should be fabricated for radial p-n junction solar cell. Most of silicon wire and/or pillar arrays have been fabricated by vapour-liquid-solid (VLS) growth because of its simple and cheap process. In the case of the VLS method has some weak points, that is, the incorporation of heavy metal catalysts into the growing silicon wire, the high temperature procedure. We have tried new approaches; one is electrochemical etching, the other is noble metal catalytic etching method to overcome those problems. In this talk, the silicon pillar formation will be characterized by investigating the parameters of the electrochemical etching process such as HF concentration ratio of electrolyte, current density, back contact material, temperature of the solution, and large pre-pattern size and pitch. In the noble metal catalytic etching processes, the effect of solution composition and thickness of metal catalyst on the etching rate and morphologies of silicon was investigated. Finally, radial p-n junction wire arrays were fabricated by spin on doping (phosphor), starting from chemical etched p-Si wire arrays. In/Ga eutectic metal was used for contact metal. The energy conversion efficiency of radial p-n junction solar cell is discussed.

• 치과방사선
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• 제29권2호
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• pp.387-396
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• 1999

In dentistry. RadioVisioGraphy was introduced as a first electronic dental x-ray imaging modality in 1989. Thereafter. many types of direct digital radiographic system have been produced in the last decade. They are based either on charge-coupled device(CCD) or on storage phosphor technology. In addition. new types of digital radiographic system using amorphous selenium. image intensifier etc. are under development. Advantages of digital radiographic system are elimination of chemical processing, reduction in radiation dose. image processing, computer storage. electronic transfer of images and so on. Image processing includes image enhancement. image reconstruction. digital subtraction, etc. Especially digital subtraction and reconstruction can be applied in many aspects of clinical practice and research. Electronic transfer of images enables filmless dental hospital and teleradiology/teledentistry system. Since the first image management and communications system(IMACS) for dentomaxillofacial radiology was reported in 1992. IMACS in dental hospital has been increasing. Meanwhile. researches about computer-assisted diagnosis, such as structural analysis of bone trabecular patterns of mandible. feature extraction, automated identification of normal landmarks on cephalometric radiograph and automated image analysis for caries or periodontitis. have been performed actively in the last decade. Further developments in digital radiographic imaging modalities. image transmission system. imaging processing and automated analysis software will change the traditional clinical dental practice in the 21st century.

• 조명전기설비학회논문지
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• 제29권4호
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• pp.1-10
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• 2015

The light emitting diodes(LED) package of new structure is proposed to promote the reliability and lifespan by maximize heat dissipation occurred on the chip. We designed and fabricated the LED packages mixing the advantages of chip on board(COB) based on conventional metal printed circuit board(PCB) and the merits of Si sub-mount using base as a substrate. The proposed LED package samples were selected for the superior efficiency of the material through the sealant properties, chip characteristics, and phosphor properties evaluations. Reliability test was conducted the thermal shock test and flux rate according to the usage time at room temperature, high-temperature operation, high-temperature operation, high-temperature storage, low-temperature storage, high-temperature and high-humidity storage. Reliability test result, the average flux rate was maintained at 97.04% for each items. Thus, the Si sub-mount based LED package is expected to be applicable to high power down-light type LED light sources.