• Journal of electromagnetic engineering and science
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• 제10권4호
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• pp.270-275
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• 2010

In a conventional opportunistic transmit (COT) cooperative relaying system, only the relays that receive signal-to-noise ratio (SNR) from the source and that exceed the threshold transmit to the destination. The COT system, however, only considers the SNR of the source-relay (S-R) path regardless that the SNR of the relay-destination (R-D) path is the opportunistic transmission condition. For that reason, it is not guaranteed that all the transmitted signals from relays exceed the threshold at the destination. Therefore we propose a double opportunistic transmit (DOT) cooperative relaying system - when both of the received SNR from a source and from a destination exceed the threshold, the relay transmits to the destination. It is shown that the proposed DOT system reduces power consumption by 6.9, 20.9, 32.4, and 41.4 % for K =3, 5, 7, and 9, respectively under the given condition of $P_{out}=1{\times}10^{-3}$ and $\overline{\gamma}_{SR}/\Gamma_{SR}$=30 dB, compared to the COT system. We noticed that the performance of the DOT system is superior to that of the COT system for the identical number of active transmit relays under the same condition of the normalized average SNR of $\overline{\gamma}_{RD}/\Gamma_{RD}$.

• Nuclear Engineering and Technology
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• 제25권4호
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• pp.561-569
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• 1993

CANDU 6 발전소의 측면 및 하단 차폐 구조에서의 방사선 선량율을 해석하기 위하여 DOT4.2-QAD-CG 접속 방법을 이용한 평가 방법이 시도되었다. 평가 결과에 의하면 주 출입구 및 신연료 장전 구역에서의 평균 방사선 선량율은 설계 목표치인. 약 6 $\mu$Sv/h 정도로 나타났으며, 또한 이러한 평가 결과는 CANDU 6 발전소에서의 실측지와도 잘 일치하고 있음을 확인할 수 있었다. 따라서, 본 논문에서 사용된 평가법은 앞으로 건설 될 CANDU 6 원자로인 월성 2, 3 및 4호기의 방사선 차폐해석에도 이용될 수 있을 것이다.

• 한국항행학회논문지
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• 제20권1호
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• pp.65-71
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• 2016

양자점 셀룰라 오토마타 (QCA; quantum-dot cellular automata)는 나노 규모의 크기와 낮은 전력 소비로 각광받고 있으며, CMOS 기술의 규모의 한계를 극복할 수 있는 대체 기술로 떠오르고 있다. 현재까지 QCA상에서 설계된 BCD-3초과 코드는 확장성을 고려하지 않았으며 대규모 회로 설계에는 적합하지 않았다. 이를 해결하기 위해 본 논문에서는 확장성을 고려한 BCD-3초과 코드 회로를 설계한다. 확장이 가능한 구조를 설계하기 위해 확장된 교차부 구조를 이용하여 입력과 출력의 흐름을 제어하고, 출력되는 값들의 동기화를 위해 5입력 다수결 게이트를 이용한다. 설계한 구조에 대해 QCADesigner를 이용하여 시뮬레이션을 수행한 후 그 결과에 대해 유효성을 검증한다. 제안된 구조는 기존의 URG BCD-3초과 코드변환기와 비교하여 32개의 게이트를 줄이며 빈 공간의 비율 또한 7% 감소시켰다. 또한 확장성이 고려되지 않은 기존의 QCA BCD-3초과 코드 변환기가 회로 확장 시 필요한 7개의 클럭을 1개의 클럭으로 줄였다.

• Current Photovoltaic Research
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• 제2권4호
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• pp.157-167
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• 2014

Colloidal quantum dot (CQD) solar cells have attracted great attention due to their cost-effectiveness and solution-processability, as well as their size-dependent optical and electrical properties. The power conversion efficiency of CQD solar cells has rapidly increased up to ~8.6%, which corresponds to the 3 - 4 fold improvement during the last 3 - 4 years. Up to now, there have been many pioneering results in CQD solar cells. Here, we review the recent progress of CQD solar cells including CQD synthesis strategy and device structure engineering.

• Current Photovoltaic Research
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• 제3권4호
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• pp.126-129
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• 2015

Over the last two decades, quantum dot (QD) solar cells have attracted much attention due to the unique properties of QDs, including band gap tunability, slow hot electron cooling, and multiple exiton generation effect. However, most of the QDs employed in photovoltaic devices contain toxic heavy-metals such as cadmium or lead, which may limit the commercial application. Therefore, recently, heavy-metal-free QDs such as Cu-In-S or Cu-In-Se have been developed for application in solar cells. Here, we review the research trends in heavy-metal-free QD solar cells, mainly focusing on Cu-In-Se QD-sensitized solar cells (QDSC).

• 대한전자공학회논문지SP
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• 제38권3호
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• pp.247-257
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• 2001

일반적 칼라 출력 장치는 제한된 범위의 색만을 재현 할 수 있다. 특히 프린터와 같이 색의 재현성이 부족한 장비에서는 하드웨어 특성에 따른 채색 면적이나 인쇄에 사용되는 용지의 특성에 따라 염료의 확산 등에 대해서도 고려해야 한다. 특히, 색을 프린트하기 위해서는 출력 과정에서 색의 선형적인 증가와 감소가 이루어져야 하며 또한 정확한 색의 모델링이 가능하여야 한다. 따라서 본 논문에서는 이를 위해 프린터 출력시 실제 채색 면적과 시각적 색감을 고려할 수 있는 디더링 방법을 제안한다. 제안된 방법은 실제 채색 면적을 고려한 패턴 데이터 베이스를 만들어 이를 디더링 패턴으로 이용하게 된다. 그리고 이 데이터 베이스에서 정확한 패턴을 선택하기 위해서는 인간시각의 색 인지력을 모델링한 대조 민감도 함수를 사용하게 된다. 따라서 본 논문에서는 저해상도의 칼라 출력장치에서도 고화질의 색을 재현할 수 있게 해준다.

• International Journal of Advanced Culture Technology
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• 제10권2호
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• pp.187-193
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• 2022

We is configured the honk changing-status technique that is to meld the square-built blow-shock status of the gleam-differential perception level (BIAL) on the honk perception lineament. The perception level condition by the honk perception lineament system is constituted with the blow-shock system. As to experimentation a ductile-dot of the gleam ductile-dot, we are found of the honk value with ductile-dot by the blow upper shift. The concept of perception level is constituted the reference of gleam-differential level for changing-status signal by the honk shock lineament. Further symbolizing a square-built changing-status of the BIAL, of the average in terms of the blow-shock lineament, and the honk ductile-dot shock that was the honk value of the far changing-status of the Ho-PL-FA-θ_AVG with 15.41±8.63 units, that was the honk value of the convenient changing-status of the Ho-PL-CO-θ_AVG with 8.70±3.06 units, that was the honk value of the flank changing-status of the Ho-PL-HO-θ_AVG with 2.65±1.19 units, that was the honk value of the edge changing-status of the Ho-PL-VI-θ_AVG with 0.51±0.18 units. The blow shock will be to investigate at the square-built ability of the blow-shock lineament with ductile-dot by the honk perception level on the BIAL, that is denote the gleam-differential lineament by the perception level system. We will be possible to curb of a lineament by the differential signal and to employ the honk data of blow shock level by the blow perception system.

• 한국의류산업학회지
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• 제20권5호
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• pp.592-599
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• 2018

The purpose of this study is to investigate consumer needs, image sensibility and preference of bedding fabric according to size and spacing of dot pattern. 18 kinds of dot pattern fabrics were designed with different diameters(6, 8, 10cm) and distances(4, 7, 10cm) in regular arrangement of diamond figure. The subjects were 162 male and female university students. The data were analyzed by SPSS 24.0. Fabrics were assessed subjectively using a 5-point scale 17 consumer needs and 33 sensory descriptors. The most consumer's needs for bedding fabric was shown to be functionality of bedding including hygiene, touch, warmth, ease of washing and management, air permeability, and hygroscopicity. The other parameters of consumer's needs were shown to be physical property and design parameter. The results of analysis of the dimension of image sensibility for fabrics with different size and spacing of dots are derived from six factors including joyfulness, coziness, uniqueness, charm, femininity, and complexity. As a result of analysis of preference with fabric kinds, there was a significant difference in preference with fabrics. The preferred fabrics were characterized by the pattern and the base fabric being striking three-dimensionally with 1/3 twill and 3/1 twill fabric. Sensory descriptors related to joyful image and unique image were analyzed as evaluation terms that can distinguish the preferences of fabrics. Correlation analysis showed the fabrics are preferred as the difference in luminance and reflectance between the base and pattern of the fabric become larger and the spacing of patterns become closer.

• 한국산학기술학회논문지
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• 제13권3호
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• pp.1330-1336
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• 2012

영상 검색 방법은 텍스트 기반, 내용 기반, 영역 기반 영상 검색, 부분 영상 검색 방법 등 다양한 연구가 이루어지고 있다. 그 중에 부분 영상 검색은 질의 영상을 포함하는 대상 영상을 찾는 문제이다. 본 논문에서는 생물정보학에서 사용하는 점 행렬 방법을 이용한 새로운 부분 영상 검색 방법을 제안한다. 점 행렬은 두 DNA 서열 간에 유사도를 시각화하는 방법으로써 영상 검색에 적용하여 두 영상 간에 유사도를 비교하는 문제로 재정의한다. 이 알고리즘을 적용하기 위해서 이차원 배열 정보인 영상을 일차원 명암도 영상으로 변환한다. 두 일차원 명암도 영상을 정렬하여 생성된 점 행렬을 이용하여 부분 영상 후보 영역을 생성한다. 실험에는 10 개의 대상 영상과 대상 영상의 부분을 복사한 영상, 축소한 영상, 확대한 영상으로 5종류의 질의 영상을 사용하였다.

• Bulletin of the Korean Chemical Society
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• 제2권3호
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• pp.96-104
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• 1981

(1) The flow data of f (stress) and ${\dot{s}$ (strain rate) for Fe and Ti alloys were plotted in the form of f vs. -ln ${\dot{s}$ by using the literature values. (2) The plot showed two distinct patterns A and B; Pattern A is a straight line with a negative slope, and Pattern B is a curve of concave upward. (3) According to Kim and Ree's generalized theory of plastic deformation, pattern A & B belong to Case 1 and 2, respectively; in Case 1, only one kind of flow units acts in the deformation, and in Case 2, two kinds flow units act, and stress is expressed by $f={X_1f_1}+{X_2f_2}$where $f_1\;and\;f_2$ are the stresses acting on the flow units of kind 1 and 2, respectively, and $X_1,\;X_2$ are the fractions of the surface area occupied by the two kinds of flow units; $f_j=(1/{\alpha}_j) sinh^{-1}\;{\beta}_j{{\dot{s}}\;(j=1\;or\;2)$, where $1/{\alpha}_j\;and\;{\beta}_j$ are proportional to the shear modulus and relaxation time, respectively. (4) We found that grain-boundary flow units only act in the deformation of Fe and Ti alloys whereas dislocation flow units do not show any appreciable contribution. (5) The deformations of Fe and Ti alloys belong generally to pattern A (Case 1) and B (Case 2), respectively. (6) By applying the equations, f=$(1/{\alpha}_{g1}) sinh^-1({\beta}_{g1}{\dot{s}}$) and $f=(X_{g1}/{\alpha}_{g1})sinh^{-1}({\beta}_{g1}{\dot{s}})+ (X_{g2}/{\alpha}_{g2})\;shih^{-1}({\beta}_{g2}{\dot{s}})$ to the flow data of Fe and Ti alloys, the parametric values of $x_{gj}/{\alpha}_{gj}\;and\;{\beta}_{gs}(j=1\;or\;2)$ were determined, here the subscript g signifies a grain-boundary flow unit. (7) From the values of ($({\beta}_gj)^{-1}$) at different temperatures, the activation enthalpy ${\Delta}H_{gj}^{\neq}$ of deformation due to flow unit gj was determined, ($({\beta}_gj)^{-1}$) being proportional to , the jumping frequency (the rate constant) of flow unit gj. The ${\Delta}H_{gj}\;^{\neq}$ agreed very well with ${\Delta}H_{gj}\;^{\neq}$ (self-diff) of the element j whose diffusion in the sample is a critical step for the deformation as proposed by Kim-Ree's theory (Refer to Tables 3 and 4). (8) The fact, ${\Delta}H_{gj}\;^{\neq}={\Delta}H_{j}\;^{\neq}$ (self-diff), justifies the Kim-Ree theory and their method for determining activation enthalpies for deformation. (9) A linear relation between ${\beta}^{-1}$ and carbon content [C] in hot-rolled steel was observed, i.e., In ${\beta}^{-1}$ = -50.2 [C] - 40.3. This equation explains very well the experimental facts observed with regard to the deformation of hot-rolled steel..