• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.225-225
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• 2016

PHOLED devices which have the structure of ITO/HAT-CN(5nm)/NPB(50nm)/EML(47nm)/TPBi(10nm)/Alq3(20nm)/LiF(0.8nm)/Al(100nm) are fabricated to investigate the diffusion length of the triplet exciton by using double-quantum-well(DQE) EML structure. To fabricate DQW structures, Ir(ppy)3(2% wt) and Ir(btp)2(8% wt) are used as green and red emission zones, respectively. In DQW structured EML, as shown in Fig. 1, 1nm thick layers of green and red emission zones are located middle of the EML, and the distance between these wells(x) is changed from 0nm to 10nm. As shown in Fig. 2, the emission spectra from DQW PHOLED devices are changed with different x. The intensity of the green emission(520nm) is decreased when x is decreased, and it goes to near zero when x=0nm. This behavior can be identified as the diffusion of the triplet excitons from Ir(ppy)3 to Ir(btp)2 by the Dexter energy transfer(DET). From the external quantum efficiency(EQE) of the red emission, as shown in Fig. 3, the diffusion length of the triplet excitons can be determined by the equation of DET rate, R=A Exp(-2RDA/L), where RDA is donor-acceptor distance and L is the sum of the van der Wals radii. As a result, the measured data of the red EQEs with different x are identified to theoretical result from the equation of DET rate(Fig. 4). From this results, we could confirm that the diffusion length of the triplet excitons can be determined by using DQW structure and this method is very useful to investigate the behavior of the excitons in PHOLEDs.

• Korean Journal of Mathematics
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• 제7권2호
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• pp.159-166
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• 1999

For classical elliptic pseudodifferential operators $A({\lambda})$ of order $m$ > 0 with parameter ${\lambda}$ of weight ${\chi}$ > 0, it is known that $logDet_{\theta}A({\lambda})$ admits an asymptotic expansion as ${\theta}{\rightarrow}+{\infty}$. In this paper we show, with some assumptions, that the coefficients of ${\lambda}^-{\frac{n}{\chi}}$ can be expressed by the values of zeta functions at 0 for some elliptic ${\psi}$DO's on $M{\times}S^1{\times}{\cdots}{\times}S^1$ multiplied by $\frac{m}{c_{n-1}}$.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 추계학술대회 논문집
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• pp.331-337
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• 2013

Acoustic Emission technique is widely applied to develop the early fault detection system, and the problem about a signal processing method for AE signal is mainly focused on. In the signal processing method, envelope analysis is a useful method to evaluate the bearing problems and Wavelet transform is a powerful method to detect faults occurred on rotating machinery. However, exact method for AE signal is not developed yet. Therefore, in this paper two methods which are Hilbert transform and DET for feature extraction. In addition, we evaluate the classification performance with varying the parameter from 2 to 15 for feature selection DET, 0.01 to 1.0 for the RBF kernel function of SVR, and the proposed algorithm achieved 94% classification accuracy with the parameter of the RBF 0.08, 12 feature selection.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.562-566
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• 2004

In this paper, we propose a method for constructing terrestrial/cable PSIP converting system, so-called a PSIP converter, which is converting terrestrial PSIP into cable PSIP for a data broadcasting service in the interoperable network of terrestrial and cable, and define an interface between the PSIP converter and the OOB SI generator by using PMCP messages compliant to ATSC T3/S1. The exiting PSIP converter just converts terrestrial PSIP into cable PSIP compliant to ATSC and OCAP standard and transmits by a MPEG-2 TS format. That is to say, it is not for the digital data broadcasting but for the digital broadcasting. Say in other word, the proposed PSIP converter is designed to convert and transmit PSIP including DET information which is necessary data event information for data broadcasting service. In addition, the PSIP converter can support various types of PSIP information to the OOB SI generator by using PMCP messages defined by a hierarchical structure as per each channel, audio/video event, data event and so on.

• 약학회지
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• 제30권6호
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• pp.329-333
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• 1986

6-[3-(Hydroxymethyl)-2, 3-epoxybutyl]-3, 5-dimethoxyphenol was synthesized by means of the eight steps, such as allylether, Claissen rearrangement, tosylation, oxidation, Wittig reaction, reduction and epoxidation from 3, 5-dimethoxyphenol. The epoxidation of 6-[3- (hydroxymethyl)-2-butenyl]-3,5-dimethoxy phenol using the L-(+)-diethyltartrate(DET), titanium (IV) isopropoxide Ti[(O-iPr)$_4$] and t-butylhydroperoxide(TBHP) is described.

• 대한화학회지
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• 제38권2호
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• pp.160-168
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• 1994

다섯자리 Schiff base의 molybdenum(Ⅴ)착물로써 [Mo(Ⅴ)O(Sal-DET)(NCS)] 와 [Mo(Ⅴ)O(Sal-DPT)(NCS)]들을 Sabat법에 의해 합성하였다. 이들 착물들의 원소분석, IR-spectrum, UV-Vis spectroscopy 및 Thermogravimetric analysis(T.G.A.)곡선으로부터 리간드 대 금속의 몰비가 1:1착물임을 확인하였다. 0.1M tetraethyl ammonium perchlorate(TEAP)지지전해질을 포함한 비수용매에서 순환 전압-전류법과 시차펄스 폴라그래피에 의한 전기화학적 측정으로부터 이들 착물들은 dimer로 형성된 후, 일전자 전이의 확전자 전이의 확산지배적인 환원과정이 다음과 같이 네단계로 진행됨을 알았다. 2Mo(Ⅴ)$\rightleftarrow^{e-}$ Mo(Ⅴ)Mo(Ⅳ) $\longrightarrow^{e-}$ 2Mo(Ⅳ), Mo(Ⅳ)$\longrightarrow^{e-}$ Mo(Ⅲ) $\longrightarrow^{e-}$ Mo(Ⅱ)

• 대한수학회논문집
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• 제12권4호
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• pp.841-849
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• 1997

A square matrix A with $per A \neq 0$ is called convertible if there exists a {1, -1} matrix H such that $per A = det(H \circ A)$ where $H \circ A$ denote the Hadamard product of H and A. In this paper, ranks of convertible {0, 1} matrices are investigated and the existence of maximal convertible matrices with its rank r for each integer r with $\left\lceil \frac{n}{2} \right\rceil \leq r \leq n$ is proved.

• 한국컴퓨터정보학회논문지
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• 제19권11호
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• pp.17-24
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• 2014

본 논문에서는 저속으로 회전하는 유도 전동기의 베어링 결함을 검출하기 위해 음향 방출 신호와 히스토그램 모델링을 이용하는 방법을 제안한다. 제안한 방법은 정규화된 결함 신호가 구성하는 히스토그램의 포락선을 모델링하여, 부분 상관 계수와 DET(Distance Evaluation Technique) 기법을 이용하여 결함 유형별 고유한 특징을 추출 및 선택한다. 추출된 특징을 SVR(Support Vector Regression) 분류기의 입력으로 사용하여 베어링의 내륜, 외륜 및 롤러 결함을 분류한다. 최적의 분류 성능을 위해 SVR 커널함수의 매개변수를 0.01에서 1.0까지 변화시키고, 특징 개수는 2에서 150까지 변화시키면서 실험한 결과, 0.64-0.65의 매개변수와 75개의 특징 개수에서 제안한 방법은 약 91%의 분류 성능을 보였고, 또한 기존의 결함 분류 알고리즘보다 높은 분류 성능을 보였다.

• 한국병원경영학회지
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• 제23권3호
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• pp.87-103
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• 2018

Purpose: This study investigates the best appointment pattern which can enhance customer's satisfaction and hospital's efficient management reflecting plastic surgery clinic's service characteristics. Methodology: The data of this study is obtained from Plastic surgery Clinic which is located in the civic center. By collecting and analyzing the data, we build the simulation model using ARENA. Based on 5 appointment patterns that was suggested in formal appointment scheduling studies, we experiment 3 simulation models; 'Basic Appointment Pattern' that has no restriction, 'Restriction on Second Customer' that restricts the number of second customer's in each slot, 'Restriction on Process Time' that restricts the number of second customer who has long process time in each slot. We can check robustness of the appointment patterns by experimenting on off-peak day and peak day, during peak season. Findings: This study confirms that these 2 restrictions can give a better result than 'Basic Appointment Pattern' that just simply distributes customers by number. Especially, the performance of Triangle-like pattern which is the best appointment pattern in the formal study has been improved by adding restrictions. Based on 'DET', 'Restriction on Second Customer' shows a better result. Meanwhile, based on 'E(WT)', 'Restriction on Process Time' shows a better result. Overall, based on 'DET+E(WT)', 'Restriction on Second Customer' shows a better result. Practical Implications: The purpose of each hospital may alter as demand for plastic surgery grows increasingly. Thus, each hospital should be always prepared to introduce appointment pattern for changed purpose. In order to respond flexibly to these changes, it is necessary for medical personnel to improve the awareness or for hospital to create an environment by constructing appointment program so that medical personnel does not need to put more labor on work.

• 한국소음진동공학회논문집
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• 제24권7호
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• pp.555-561
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• 2014

Acoustic Emission technique is widely applied to develop the early fault detection system, and the problem about a signal processing method for AE signal is mainly focused on. In the signal processing method, envelope analysis is a useful method to evaluate the bearing problems and wavelet transform is a powerful method to detect faults occurred on rotating machinery. However, exact method for AE signal is not developed yet for the rotating machinery diagnosis. Therefore, in this paper two methods which are processed by Hilbert transform and DET for feature extraction. In addition, we evaluate the classification performance with varying the parameter from 2 to 15 for feature selection DET, 0.01 to 1.0 for the RBF kernel function of SVR, and the proposed algorithm achieved 94 % classification of averaged accuracy with the parameter of the RBF 0.08, 12 feature selection.