• 한국세라믹학회지
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• 제47권4호
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• pp.329-332
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• 2010

In order to investigate the effect of tail state on the electrical and the optical properties in amorphous IGZO(a-IGZO), a-IGZO films were deposited at room temperature on fused silica substrats using pulsed laser deposition method. The laser pulse energy was used as the processing parameter. In-situ post annealing was carried out at $150^{\circ}C$ right after the film deposition. The $O_2$ partial pressure during the deposition and the post annealing was fixed to 10mTorr. The carrier mobility of the a-IGZO films had a range from 2 to $18\;cm^2/Vs$ at carrier concentrations greater than $10^{18}\;cm^{-3}$. As the laser energy density increased, the Hall mobility increased. And post annealing improved the Hall mobility, as well. The optical property was examined using the ultraviolet-visible spectroscopy. The a-IGZO films that have low Hall mobility exhibited stronger and broader absorption tails in >3.0 eV region. Post annealing reduced the intensity of the tail-like absorption. The absorption tail in a-IGZO films is an important factor which affects the electrical and the optical properties.

• Journal of Genetic Medicine
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• 제15권1호
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• pp.13-16
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• 2018

X-linked juvenile retinoschisis (XLRS) is characterized by the progressive loss of visual acuity and vitreous hemorrhage. XLRS is caused by a mutation of retinoschisin 1 (RS1) gene at Xp22.13. In the current report, a 2-year-old Korean patient with XLRS was described. The germline deletion of exon 1 was identified in the RS1 gene. Considering X-linked inheritance pattern, validation of a carrier state of a patient's mother is important for the genetic counseling of other family members and for the future reproductive plan. To confirm the carrier state of his mother, the multiplex ligation-dependent probe amplification analysis was done using peripheral leukocytes and found the heterozygous deletion of exon 1 in his mother.

• Journal of Magnetics
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• 제18권1호
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• pp.43-49
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• 2013

A pulsed ferrite magnetic field generator (FMFG) was designed for the use in the 1000 m long through-the-earth (TTE) communication system for mining disaster situations. To miniaturize the TTE system, a ferrite core having 10,000 of permeability was used for the FMFG. Attenuation of the magnetic field intensity from the FMFG (200-turn and 0.18 m diameter) was calculated to be 89.95 dB at 1000 m depth soil having 0.1 S/m of conductivity. This attenuation was lower than 151.13 dB attenuation of 1 kHz electromagnetic wave at the same conditions. Therefore, the magnetic-field was found to be desirable as a signal carrier source for TTE communications as compared to the electromagnetic wave. The designed FMFG generates the magnetic field intensity of $1{\times}10^{-10}$ Tesla at 1000 m depth. This magnetic field is detectable by compact magnetic sensors such as flux gate or magnetic tunneling junction sensor. Therefore, the miniature FMFG TTE communication system can replace the conventional electromagnetic wave carrier type TTE system and allow reliable signal transmission between rescuer and trapped miners.

• 전기전자학회논문지
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• 제28권1호
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• pp.104-109
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• 2024

본 연구에서는 다양한 가스 분위기에서 후열처리를 진행한 후 Ga₂O₃/SiC 이종접합 다이오드의 깊은 준위 결함 변화를 Deep Level Transient Spectroscopy(DLTS) 기법으로 분석하여 깊은 준위 결함의 변화가 Ga₂O₃/SiC 이종접합 소자의 전기적 특성에 미치는 영향을 조사하였다. 또한, J-V 측정 및 Hall 측정을 통한 전기적 특성 분석을 실시하였고, N₂ 분위기에서 열처리된 소자에서 3.06 × 10^-2 A/cm²로 가장 높은 on-state current가 측정되었으며, carrier concentration은 3.8 × 10¹⁴ cm^-3로 증가하는 것이 관측되었다. 이는 후열처리 분위기에 따른 깊은 준위 결함의 변화가 전기적 특성에 영향을 미칠 수 있음을 시사한다.

• 지식경영연구
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• 제14권1호
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• pp.73-94
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• 2013

Customer's purchase state consists of purchase inertia and variety-seeking. As the growing brand familiarity triggers the increase of brand attractiveness, customers purchase state will be of inertia. However the excessively growing brand familiarity ignites the decrease of brand attractiveness. Followingly the purchase state will be tend to plunge into the variety-seeking state. The main topic of this study is to validate the asymmetric formation of customer's purchase states between inertia and variety-seeking. In order to follow up the main topic, this article introduces a model to freely describe the velocity of value changes depending upon the purchase states. This model will help overcome the limitation of the past studies having been based on the symmetric value changes. Based on this approach marketer will be able to decide the timing of sales promotions. This research utilized local telecommunication carrier's database of smartphone application purchase/download records. This database was collected from two years (2009 and 2010) span, the time when the smartphones started commodifying in Korea whilst most of the past studies had used purchase data of maturity stage products. From this approach utilizing the introduction stage data in the product life cycle, the probability of brand choice depending upon the purchase state on the early-stage can be probed. Moreover, this study tries to expand the research methodology from the other areas of research by knowledge sharing. Here this study introduces the methodology of section-aggregated multinomial logit to simultaneously estimate the parameters that were included in the plural multinomial logit functions while the plural functions were inter-connected. This adoption of section-aggregated multinomial logit model procedures from the computerized statistics areas is expected to nourish the marketing research for more precise analysis and estimation of effects of marketing activities.

• 동의생리병리학회지
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• 제18권5호
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• pp.1426-1436
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• 2004

There have been several reports on the relationship between G protein β3 subunit gene (GNB3), angiotensin converting enzyme gene (ACE), β3-adrenergic receptor gene (ADRB3), and β2-adrenergic receptor gene (ADRB2) genotype and obesity or obesity related disease. The objective of this study was to examine the relationship between the combinations of these four genes' polymorphism and probability of obesity related disease in Korean female subjects. The experimental group was consisted of 85 obese Korean female subjects (body mass index, BMI≥27㎏/㎡). To determine the polymorphism, genomic DNA was isolated, and PCR was performed. Serological examinations (fasting plasma glucose, FPG; aspartate aminotranferase, AST; alanine aminotransferase, ALT; total cholesterol, TC; triglyceride, TG; high density lipoprotein-cholesterol, HDL; low density lipoprotein-choles terol, LDL) were carried by an autoanalyzer and serological methods. BMI, waist circumference (WC), hip circumference and waist hip ratio (WHR) were measured. Consequencely in the analysis with grouping of general genotyping and variant allele carrier/non-carrier, the result was not significantly different within all gene combinations and polymorphic pairings except higher waist circumference in Arg16Arg group of ADRB2 codon16 (P=0.024). And there was no significantly contrast result about age, height, weight, AST and ALT that are index feature of liver and gall bladder disease in polymorphic pairings of gene combinations. However, the statistical analysis of waist-hip ratio and waist circumference that could be recognized as the physical type of obesity showed T-Arg16 pairing carrier in GNB3-ADRB2 codon16 combination had increased WHR and WC significantly (P=0.046 and P=0.015 respectively). Futhermore, the levels of total cholesterol (TC) and low density lipoprotein choresteral (LDL) were significantly lower in C-I pairing of GNB3-ACE combination (P=0.032 and P=0.005). These results suggest that the T-Arg16 pairing carrier in GNB3-ADRB2 codon16 gene might have increased waist circumference and C-I pairing carrier in GNB3-ACE combination have lower possibility of contraction of cardiovascular disease related cholesterol and LDL despite of obese state.

• 대한전자공학회논문지SP
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• 제39권6호
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• pp.718-726
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• 2002

본 논문은 유럽형 디지털 TV의 표준인 Digital Video Broadcasting(DVB) 수신기에 사용되는 비터비 디코더의 새로운 아키텍처를 제한하였다. OFDM system의 multiple carrier에서 각각의 sub-carrier에 Channel State Information(CSI)를 추정하여, 각 symbol의 bit-metric을 구할 때 가중치를 주는 방식으로 적용하였다. 가중치를 적용한 bit-metric은 심볼 디인터리버와 비트 디인터리버를 통과한 후에 비터비 디코더에 전달된다. 즉, CSI는 두개의 인터리버를 거친 후에도 그에 상응하는 비트에 정확히 적용될 수 있음을 말한다. 본 논문에서 제안한 새로운 아키텍쳐는 Rayleigh fading 채널에서 6~13dB의 상당한 성능의 향상을 보임을 변조 방식에 따라 시뮬레이션을 통해 보였다. 이 결과는 기존의 방식에 비하여 3.7~10.3dB 더 나은 성능이다.

• 대한전자공학회논문지SD
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• 제44권2호
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• pp.13-18
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• 2007

본 연구에서는 Lateral DMOS 소자열화 메카니즘이 게이트 산화층의 두께에 따라 다른 것을 측정을 통하여 알 수 있었다. 얇은 산화층 소자는 채널에 생성되는 계면상태와 drift 영역에 포획되는 홀에 의하여 소자가 열화 되고 두꺼운 산화층 소자에서는 채널 영역의 계면상태 생성에 의해서 소자가 열화 되는 것으로 알 수 있었다. 그리고 소자 시뮬레이션을 통하여 다른 열화 메카니즘을 입증할 수 있었다. DC 스트레스에서의 소자 열화와 AC 스트레스에서 소자열화의 비교로부터 AC스트레스에서 소자열화가 적게 되었으며 게이트 펄스의 주파수가 증가할수록 소자열화가 심함을 알 수 있었다. 그 결과로부터 RF LDMOS 에서는 소자열화가 소자설계 및 회로설계에 중요한 변수로 작용할 수 있음을 알 수 있었다.

• 대한조선학회논문집
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• 제53권1호
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• pp.37-44
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• 2016

Recently researchers are conducting a lot of research related to EEDI in order to satisfy IMO resolution MEPC. Especially they are interested in design of energy saving device. This paper is to design the asymmetric pre-swirl stator for 160K LNG carrier in order to reduce energy. Two types of the asymmetric pre-swirl stator are taken into account; constant and variable pitch angle stators. “constant” and “variable” mean state that the pitch of stators change by radius. The dimensions of the stators are initially determined using potential-flow code. The propulsion performances of the stators are predicted using viscous-flow code. The model test is carried out in towing tank in PNU. Prediction of ship performance generally follow ITTC recommended. Ship wake prediction was done by two method, ITTC 1978 and ITTC 1999. Therefore propulsion performances were compared ITTC 1978 with ITTC 1999 methods. Comparison components are delivered power and thrust deduction coefficient of the model. Final pre-swirl stator is selected by comparing experiment and CFD.

• 한국통신학회논문지
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• 제30권6C호
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• pp.423-433
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• 2005

다중 반송자를 사용하는 CDMA 통신 시스템에서 주파수 영역의 전력과 시간 영역의 전송율을 적응적으로 사용하는 시스템을 분석하였다. 수신단으로 부터 얻는 이상적인 채널상태 정보를 가정하고, 주파수 영역에서는 각 사용자의 부채널 중에서 가장 채널상태가 좋은 한 대역을 선택하고, 시간영역에서는 목표 수신 품질을 만족하도록 전송율을 조정한다. 단일 사용자의 경우에 평균 BER을 최소화 할 수 있는 최적의 전송 방식의 식을 유도하였다. 채널 상태 역수 법이 사용 대역의 수나, 평균 전송양이 증가할 때 최적의 알고리듬이라는 사실 또한 증명하였다. 수학적 분석과 시뮬레이션 결과 제안된 주파수 시간 적응 알고리듬을 사용한 방식이 주파수영역에서만 선택적인 방법을 사용하는 MC-CDMA 방식과 비교하여 현격히 좋은 성능을 보임을 보였다. 또한 제안된 적응형 MC-CDMA 전송방식과 기존의 RAKE 수신기를 사용하고 시간 영역에서 적응적 방식을 사용하는 DS-CDMA 시스템과 성능을 비교하였다.