• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.415-417
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• 2009

Color stable and efficient two wavelength white organic light emitting diodes (OLEDs) were fabricated using a iridium(III)[bis(4,6-difluorophenyl)-pyridinato-N,$C^2$'] picolinate (FIrpic) as a blue phosphorescent emitter and a bis(1-phenylisoquinolinato-$C^2$,N)iridium (acetylacetonate) ((piq)$_2$Ir(acac)) as a red phosphorescent emitter. The emitting layers consist of two blue emitting layers and one red emitting layer which is between the two blue layers. The device reaches the peak efficiencies of 7.84 % and 10.3 cd/A at 0.6 mA/$cm^2$. Furthermore, there was little change of EL spectra according to current density change in the device.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.697-699
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• 2009

Optical properties of white organic light-emitting devices (WOLEDs) fabricated utilizing a phosphor layer acting as a color conversion layer were investigated. The WOLEDs were achieved due to the enhancement in the color conversion efficiency of the phosphor layer, and the chromaticity coordinates of WOLEDs were (0.29, 0.33).

• KIEE International Transaction on Systems and Control
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• v.2D no.2
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• pp.97-107
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• 2002

In this paper, we propose the concept of orthonormalized compressed measurement for the stability analysis of discrete linear time-varying Kalman filters. Unlike previous studies that deal with the homogeneous portion of Kalman filters, the proposed Lyapunov method directly deals with the stochastically-driven system. The orthonorrmalized compressed measurement provides information on the a priori state estimate of the Kalman filter at the k-th step that is propagated from the a posteriori state estimate at the previous block of time. Since the complex multiple-step propagations of a candidate Lyapunov function with process and measurement noises can be simplified to a one-step Lyapunov propagation by the orthonormalized compressed measurement, a stochastic radius of attraction can be derived that would be impractically difficult to obtain by the conventional multiple-step Lyapunov method.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.729-732
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• 1995

This paper presents a Generalized Iteration (GI) which includes power method, inverse power method, shifted inverse power method, and Rayleigh quotient iteration (RQI), and modified RQI (MRQI). Furthermore, we propose a GI-based algorithm to find arbitrary eigenpairs for Hermitian matrices. The proposed algorithm appears to be much faster and more accurate than the valuable generalized MRQI of Hu (GMRQI-Hu). The idea of GI is also employed to speed up the GMRQI-Hu and we propose a modified version of Hu's GMRQI (GMRQI-Hu-mod) which is improved in the convergence rate. Some numerical simulation results are presented to confirm our contributions

• Journal of Microbiology
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• v.33 no.4
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• pp.283-288
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• 1995

We have identified hemolysin rendering virulency of Vibrio anguilarum grown at 23.deg.C which was evaluated on human RBCs. Hemolysin itself was separated as a single band on non-denaturing gel electrophoresis. Vibrio hemolysin was destroyed by trypsin and proteinase K and was heat labile. Optimal pH for activity was around pH 6 while pI of the molecule was recognized as 5.7, with relative distance (R$\sub$f/) on non-denaturing gel was 0.7. Addition of EDTA and FeCI$\sub$3/ drew the possibility that the production of hemolysin was mainly induced to overcome iron deficiency inside host animalsd infection.

• Journal of Microbiology
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• v.33 no.4
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• pp.289-294
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• 1995

The action mechanism of hemolysin rendering virulency of Vibrio anguilarum has not clarified as yet, even though there were several possible factors explained. We have studied hemolytic kinetics performed by hemolysin from V. anguillarum strain V7 as well as binding of hemolysin to RBC membrane. Maximal rate of hemolysis and duration of lag phase were directly and inversly correlated to the concentration of hemolysin used. Hemolysin molecules are known to bind consumptively with proper diameter, while other protectants with smaller diameter could not. In conclusion, hemolysin should bind irreversibly to RBC membrane exert hemolysis distorting osmotic pressure. The binding could be hindered by spatial structure of the RBC surfacem which might be caused by sialic acid.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.1-4
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• 2000

We have performed ab initio pseudopotential electronic structure calculations for various edge geometries of the (n,n) singlewall nanotube with or without applied fields. Among the systems studied, the one with the zigzag edge exposed by a slant cut is found to be the most favorable for the emission due to the existence of unpaired dangling bond states around the Fermi level. The next favorable geometry is the capped nanotube where $\pi$-bonding states localized at the cap and pointing to the tube axis direction occur at the Fermi level. A scaling rule of the induced field linear in the aspect ratio of the tube is also obtained.

• Journal of the Korean Vacuum Society
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• v.7 no.s1
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• pp.30-36
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• 1998

The plasma-spray technique is currently the most frequently used method to produce calcium phosphate coatings. Hydroxyapatite(HAp), one form of calcium phosphate, is preferred by its ability to form a direct bond with living bone, resulting in improvements of implant fixation and faster bone healing. Recently, concerns have been raised regarding the viable use and long-term stability of plasma-spray HAp coatings due to its nature of comparatively thick, porous, and poor bonding strength to metal implants. Thin layers (maximum of few microns) of calcium phosphate were formed by an e-beam evaporation with and without ion bombardments. The Ca/P ration of film was controlled by either using the evaporants having the different ration of Ca/P with addition of CaO, or adjusting the ion beam assist current. The Ca/P ration had great effects on the structure formation after heat treatment and the dissolution bahavior. The calcium phosphate films produced by IBAD exhibited high adhesion strength.

• Annual Conference of KIPS
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• 2022.11a
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• pp.66-68
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• 2022

활용도가 높아지고 있는 최근의 딥러닝 애플리케이션 등을 사용하기 위해서 기존의 CPU 구조로는 한계가 있어 GPU, TPU 등의 하드웨어로 가속하려는 노력이 있어왔다. 하지만 물리적인 제약으로 인해 메모리 대역폭에 한계가 있으며, 이를 뛰어넘기 위해 메모리 안에서 직접 연산을 수행하는 Processing-in-Memory 기술이 떠오르고 있다. 본 논문은 PIM 기술을 사용할 때의 불이익을 감수하면서 장점을 최대한 활용하는 방법들에 관해서 서술하였다.

• Journal of Korean Society for Atmospheric Environment
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• v.11 no.E
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• pp.55-62
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• 1995

The distribution of airborne mercury was investigated from several districts of Seoul, five other major cities and two rural areas during the period April, 1994 to March, 1995. The method used in this study involves absorption of gaseous mercury on CHromosorb$^R$ A coated with gold and detection by cold vapor atomic absorption spectroscopy. The atmospheric mercury concentrations in Seoul ranged from N.D. to 120.17 ng m$^3$ (mean 27.01 $\pm 9.42 ng m^{-3}, N=139$), while those in rural areas ranged from 1.72 to 8.24 ng $m^{-3} (mean 4.57 \pm 3.07 ng m^{-3}, N=5$). The spatial distribution characteristics of mercury distribution in urban air were examined by comparing mercury levels as a function of the distance from the urban center. Temporal distribution trends of airborne mercury were also studied using the monthly mean mercury data of various districts in Seoul. The atmospheric mercury concentration around Mokdong wastes incinerator in Seoul were also investigated.