• 수산해양교육연구
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• 제13권2호
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• pp.168-177
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• 2001

The flow pattern and water mass structure in the Chungmu channel were investigated using the field observations during June and July, 2001. The currents in the channel may be regarded as a hydraulic current decided by difference of tide levels between two sides in the channel. The strongest current in the channel occurs around in high water and low water. The coefficient C to be determined the characteristics of velocity in the channel was obtained from an equation, $u=C{\sqrt{2gh}}$ and ranges from 0.37 to 0.65 in the Chungmu Channel at the spring tide and from 0.23 to 0.37 at the neap tide. Eastward tidal transport is usually larger than that of westward transport in Chungmu the Channel. Sea water exchange rates are 39.2% in spring tide and 20.5% in neap tide respectively. The water mass structure in the channel is changed by the speed of the tidal current. The water mass is well mixed at the high water when the current is strong and is stratified at slack water when the current is weak.

• 한국통신학회논문지
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• 제28권11B호
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• pp.1031-1037
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• 2003

본 논문에서는 Ad-hoc 망인 블루투스 시스템의 각 채널의 질 정보를 이용하여 대역폭을 효율적으로 사용하는 새로운 스케줄링 기법을 제시하였다. 특히 제시한 기법은 채널의 불균형한 환경과 여러 가지 특성의 데이터가 혼합되어 전송되는 경우, 특정한 채널에 데이터가 집중되는 경우에 효과적인 것으로 나타났다. 각 채널의 부분 정보를 이용하여 가중치를 계산하고 그 값을 GPS 알고리즘을 수정한 새로운 스케줄링 기법에 적용하였으며 NS-2와 블루학 시뮬레이션을 통해 제시한 기법의 효율성을 검증하였다.

• Management Science and Financial Engineering
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• 제9권1호
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• pp.29-49
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• 2003

This paper develops channel reallocation methodologies for survival transmission networks, Any failure on a high-speed telecommunication network needs to be restored rapidly and a channel real-location methodology has an important role for the fast restoration. This paper considers the channel reallocation problems under a line restoration with distributed control, where the line restoration restores the failed channels by rerouting the channels along the two alternative routes. The objective is to determine the optimal number of rerouting channels on the alternative rerouting paths of a given transmission network, where the optimality criteria are the first, the last and the mean restoration times. For each criterion, the problem is formulated as a mixed integer programming and the optimal channel reallocation algorithm is suggested based upon the characterization of the optimal solution.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2544-2547
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• 2008

A micro channel heat sink has been studied and optimized for mixed pressure driven and electroosmotic flows through three-dimensional numerical analysis. The effects of ionic concentration represented by zeta potential and Debye thickness are studied with the various steps of externally applied electric potential. Optimization of the micro channel heat sink has been performed considering two design variables related to the micro channel width, depth and fin width. The surrogate-based optimization is performed using a search algorithm taking overall thermal resistance as objective function. The thermal resistance is found to be more sensitive to channel width-to-depth ratio than fin width-to-depth of channel ratio.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제22권4호
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• pp.217-239
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• 2018

This paper examined the MHD and thermal behavior of unsteady mixed convection flow of a rotating fluid in a porous parallel plate channel in the presence of Hall current and heat source. The exact solutions of the concentration, energy and momentum equations are obtained. The influence of each governing parameter on non dimensional velocity, temperature, concentration, skin friction coefficient, rate of heat transfer and rate of mass transfer at the porous parallel plate channel surfaces is discussed. During the course of numerical computation, it is observed that as Hall current parameter and Soret number at the porous channel surfaces increases, the primary and secondary velocity profiles are increases while the primary and secondary skin friction coefficients are increases at the cold wall and decreases at the heated wall. In particular, it is noticed that a reverse trend in case of heat source parameter.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.573-574
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• 2008

In this paper, we propose a mixed driving circuit for the source driver of QVGA-scale TFT-LCD driver IC to reduce the area of the source driver. In the mixed driving circuit, graphic data pass or go through the mixed channel driver whether RGB data are the same or not. The mixed driving circuit has been designed in transistor level using the 0.35um CMOS technology and has been verified using Hspice.

• JSTS:Journal of Semiconductor Technology and Science
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• 제9권4호
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• pp.233-239
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• 2009

A mixed CT/DT 2-1 cascaded ${\Sigma\Delta}M$ which includes a first stage CT ${\Sigma\Delta}M$ and a second stage mismatch insensitive two-channel time-interleaved DT ${\Sigma\Delta}M$ is proposed. With this approach, the advantages of both CT and DT ${\Sigma\Delta}Ms$ including high speed operation, inherent anti-aliasing filter, and good coefficient matching can be achieved. The two-channel time-interleaved ${\Sigma\Delta}M$ used in the second stage alleviates the speed constraints of the DT ${\Sigma\Delta}M$, whereas enables better matching between the analog and digital filter coefficients compared to CT ${\Sigma\Delta}Ms$.

• 대한산업공학회지
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• 제25권3호
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• pp.351-359
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• 1999

We present a new approach to the analysis of mobile cellular communication systems under the environment of mixed platforms adopting a guard channel scheme. We assume general cell residence time distributions according to platform-types. Our system model is based on a heterogeneous M/G/c loss system with customer-dependent guard channels, where heterogeneous customers with different service time distributions have different numbers of their own guard channels. We develop the general formula of steady state probabilities for the heterogeneous M/G/c loss system with customer-dependent guard channels. The mean channel occupancy times of new and handoff calls are rigorously derived under a general setting. Finally, our numerical results show that the blocking probability and the forced termination probability are sensitive to the cell residence time distributions.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.22.1-22
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• 2001

In this paper we present Multiple-Channel Active Noise Control[ANC] system by employing Independent Component Analysis[ICA] and Adaptive Network Fuzzy Inference System[ANFIS]. ICA is widely used in signal processing and communication and it use prewhiting and appropriate choice of non-linearities, ICA can separate mixed signal. ANFIS controller is trained with the hybrid learning algorithm to optimize its parameters for adaptively canceling noise. This new method which minimizes a statistical dependency of mutual information(MI) in mixed low frequency noise signal and there is no need to secondary path modeling. The proposed implementations achieve more powerful and stable noise reduction than Filtered-X LMS algorithms which is needed for LTI assumption and precise secondary error

• Journal of Electrical Engineering and Technology
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• 제7권2호
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• pp.236-239
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• 2012

In this paper, we study the transient characteristics of 4H-SiC DMOSFETs with different interface charges to improve the turn-on rising time. A physics-based two-dimensional mixed device and circuit simulator was used to understand the relationship between the switching characteristics and the physical device structures. As the $SiO_2$/SiC interface charge increases, the current density is reduced and the switching time is increased, which is due primarily to the lowered channel mobility. The result of the switching performance is shown as a function of the gate-to-source capacitance and the channel resistance. The results show that the switching performance of the 4H-SiC DMOSFET is sensitive to the channel resistance that is affected by the interface charge variations, which suggests that it is essential to reduce the interface charge densities in order to improve the switching speed in 4H-SiC DMOSFETs.