• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.367-370
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• 2007

Present study examines detonation wave propagation characteristics in annular channel. A normalized value of channel width to the annular radius was considered as a geometric parameter. A parametric study was carried out for a various regimes of detonation waves from weakly unstable to highly unstable detonation waves. Numerical approaches that used in the previous study of numerical requirements of the simulation of detonation wave propagations in 2D and 3D channel were used also for the present study with OpenMP parallization for multi-core SMP machines. The major effect of the curved geometry on the detonation wave propagation seems to be a flow compression effect, regardless of the detonation regimes. The flow compression behind the detonation wave by the curved geometry of the circular channel pushes the detonation wave front and results in the overdriven detonation waves with increased detonation speed beyond the Chapmann-Jouguet speed. This effect gets stronger as the normalized radius smaller, as expected. The effect seems to be negligible beyond the normalized radius of 10.

• 유통과학연구
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• 제21권1호
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• pp.119-128
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• 2023

Purpose: Due to COVID-19, the rapidly changing untact culture from offline to online has spread rapidly, increasing the utilization of omni-channel. However, among the studies on consumers in the online market, there are not many studies that analyze Shopping Values and attitudes toward omnichannel Acceptance. Research design, data, and methodology: This study investigated through empirical analysis how Shopping Values and innovation propensity of consumers using omni channels affect omni channel Acceptance attitudes. The analysis results based on a total of 268 questionnaires using SPSS v.23 and AMOS v.23 statistical programs are as follows. Results: First, it was found that the perceived Value of omnichannel use had a positive effect on the innovation tendency, and the pleasure Value had a greater effect than the actual Value. Second, it was found that the practical and hedonic Value of the omnichannel had a positive effect on the attitude of service Acceptance. Third, it was found that Omni Channel's consumer innovation tendency had a positive effect on service Acceptance attitude. Conclusion: This study proved that Shopping Value perception and individual innovation propensity for omnichannel services have a positive effect on Acceptance attitude, and it is of academic significance in that it expanded understanding of what factors are needed to increase Acceptance attitude of Omni Channel services.

• 한국통신학회논문지
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• 제17권11호
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• pp.1290-1298
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• 1992

본 논문은 fitting 파라미터를 배제하고 2차원적 Poisson 방정식을 도출해서 short-channel MOSFET의 model 식을 완전히 해석적으로 성립시켰다. 이로 인해 포화영역, 문턱전압, 강반전에 대한 것이 동시에 표현되는 정확한 드레인 전류가 유도되었다. 더욱이 이 model은 short-channel과 body효과, DIBL효과, 그리고 carrier운동에 대한 것도 설명할 수 있으며 온도와 $n^+$접합, 산화층에 관련되는 문턱전압도 표현할 수 있었다.

• 신재생에너지
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• 제5권1호
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• pp.18-25
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• 2009

PEMFC (Proton Exchange Membrane Fuel Cell) is a low temperature fuel cells which are high efficient and clean energy. But it has many problems like economical efficiency or durability. Because of this reason, many researchers challenge various view points. One of challenge is the flow channel design and many researchers develop new flow channel design. In addition to most of them have the anode and cathode's flow channel overlapped almost perfectly. In this case, the electrochemical reaction is almost done by the inertial force of flow. So we study on the effect of the anode and cathode's flow channel which aren't overlapped perfectly, have more diffusion effect, to PEMFC performance using CFD.

• 복식문화연구
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• 제26권1호
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• pp.109-124
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• 2018

As fashion and distribution companies have increasingly turned to implementing marketing activities that use omni-channel strategies, it is imperative to explore consumer-oriented evaluations of omni-channel shopping for fashion products. Through contributing to the growing research flow of consumer behavior within omni-channel contexts, the current study explores consumer motivations for omni-channel fashion shopping and their impacts on the decision-making stages of fashion products. The authors first performed in-depth interviews with six Korean consumers and confirmed the four types of consumer motivation for omni-channel shopping, and how decision-making processes react to fashion companies' omni- channel marketing strategies. These findings were used to set survey items for the main study. Based on the results and findings of previous literature, an online survey was conducted with 300 participants who had actual experience with omni-channel shopping for fashion products. The statistic results from the survey revealed the following: First, the in-depth interviews allowed the authors to confirm four factors of omni-channel shopping motivation (ubiquity, efficiency, convenience, and impulsiveness). Second, the survey showed the authors that among the four factors of omni-channel shopping orientation, impulsiveness had the greatest effect on consumer behaviors at the preand on-purchase stages, while the ubiquity factor had the greatest effect at the post-purchase stage. As such, the study empirically tested the omni-channel-specific factors of shopping orientation and motivation. In addition, it showed the effect of omni-channel marketing on various stages of the decision- making process and the study's limitations and implications were discussed.

• 한국군사과학기술학회지
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• 제24권6호
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• pp.655-663
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• 2021

In this paper, DFT-Based channel estimation with channel response mirroring is proposed and analyzed. In General, pilot symbols for channel estimation in MIMO(Multi-Input Multi-Output) OFDM(Orthogonal Frequency-Division Multiplexing) Systems have a diamond shape in the time-frequency plane. An interpolation technique to estimate the channel response of sub-carriers between reference symbols is needed. Various interpolation techniques such as linear interpolation, low-pass filtering interpolation, cubic interpolation and DFT interpolation are employed to estimate the non-pilot sub-carriers. In this paper, we investigate the conventional DFT-based channel estimation for noise reduction and channel response interpolation. The conventional method has performance degradation by distortion called "edge effect" or "border effect". In order to mitigate the distortion, we propose an improved DFT-based channel estimation with channel response mirroring. This technique can efficiently mitigate the distortion caused by the DFT of channel response discontinuity. Simulation results show that the proposed method has better performance than the conventional DFT-based channel estimation in terms of MSE.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.531-535
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• 2008

Present study examines the detonation wave propagation characteristics in annular channel. A normalized value of channel width to the annular radius was considered as a geometric parameter. Numerical approaches used in the previous studies of detonation wave propagation were extended to the present study with OpenMP parallelization for multicore SMP machines. The major effect of the curved geometry on the detonation wave propagation seems to be a flow compression effect, regardless of the detonation regimes. The flow compression behind the detonation wave by the curved geometry of the circular channel pushes the detonation wave front and results in the overdriven detonation waves with increased detonation speed beyond the Chapmann-Jouguet speed. This effect gets stronger as the normalized radius smaller, as expected. The effect seems to be negligible beyond the normalized radius of 10.

• Biomolecules & Therapeutics
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• 제8권1호
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• pp.53-63
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• 2000

This study was performed to elucited the mechanisms of the antidiuretic action by SKP-450, a $K^+$ channel opener, given into the vein, and of the diuretic action observed only in the ipsilateral kidney, when given into a renal artery, in dog. The antidiuretic action of SKP-450 was not affected by renal denervation or pretreatment with glibenclamide, a ATP-dependent $K^+$ channel blocker. The diuretic action of SKP-450 was inhibited by renal denervation or pretreatment with glibenclamide. SKP-450 given into carotid artery had little effect on renal function. These results suggest that the antidiuretic action of SKP-450 given into the vein is caused by some endogenous substances probably not related to $K^+$ channel, whereas the diuretic action of SKP-450 observed only in ipsilateral kidney, when given into a renal artery, is provoked through $K^+$ channel related to renal nerves.

• Journal of Advanced Marine Engineering and Technology
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• 제33권5호
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• pp.738-745
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• 2009

Underwater acoustic communication has multipath error because of reflection by sea-level and sea-bottom. The multipath of underwater channel causes receive signal to make error floor. In this paper, we propose the underwater communication system using various channel coding schemes such as RS coding, convolutional code, turbo code and concatenated code for overcoming the multipath effect in underwater channel. As shown in simulation results, characteristic of multipath error is similar to that of random error. So interleaver has not effect on error correcting. For correcting of error floor by multipath, it is necessary to use strong channel codes like turbo code. Turbo code is one of the iterative codes. And the performance of concatenated codes including RS code has better performance than using singular channel codes.

• 전자공학회논문지D
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• 제35D권12호
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• pp.53-58
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• 1998

다결정 실리콘 박막 트랜지스터를 이용한 회로의 성능 향상을 위하여 새로운 구조의 4-terminal buried channel poly-Si TFT(BCTFT)를 설계하고 제작하였다. BCTFT는 moderate 도핑이 된 buried channel을 이용하므로 기존의 다결정 실리콘 TFT보다 ON-전류와 전계 효과 이동도가 n-형과 p-형 소자 각각 5배와 10배 향상되었다. BCTFT는 moderate 도핑된 buried 채널과 counter 도핑된 body 사이의 junction 공핍에 의하여 캐리어의 이동이 억제 되므로 OFF-전류가 증가하지 않았다.