• Journal of Magnetics
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• 제12권2호
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• pp.72-76
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• 2007

We investigate the spin transfer torque in metallic multilayer system by employing Keldysh non-equilibrium Green function method. We study the dependences of the spin transfer torque on the detailed energy configuration of ferromagnetic, spacer, and lead layers. With Keldysh non-equilibrium Green function method applied to a single band model, we explore spin transfer torque effect in various layer structures and for various material parameters.

• 한국통신학회논문지
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• 제18권12호
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• pp.2001-2012
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• 1993

기존의 전전자교환기에 ISDN 기능을 부가하게 되면 가입자 모듈의 구조적인 변화가 따르게 되어 시스팀의 성능에 영향을 미치게 된다. 따라서 이러한 성능의 변화가 발생하지 않도록 시스팀을 설계하는 것이 중요하다. 본 논문은 음성급 전전자교환기인 TDX-LB 시스템에 ISDN기능을 추가 개발함에 따라 예상되는 디지틀 가입자 모듈의 성능을 평가하기 위하여 해석적인 방법으로 목표만을 확인하고, 개발된 시스팀의 성능을 측정하여 기존의 음성 시스팀과 비교함으로서 ISDN 가입자 정합 기술이 시스팀 성능에 미친 영향을 분석 하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권10호
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• pp.4873-4888
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• 2018

A joint blind parameter estimation algorithm based on minimum channel stability function aimed at the non-cooperative high-order modulated paired carrier multiple access (PCMA) signals is proposed. The method, which uses hierarchical search to estimate time delay, amplitude and frequency offset and the estimation of phase offset, including finite ambiguity, is presented simultaneously based on the derivation of the channel stability function. In this work, the structure of hierarchical iterative processing is used to enhance the performance of the algorithm, and the improved algorithm is used to reduce complexity. Compared with existing data-aided algorithms, this algorithm does not require a priori information. Therefore, it has significant advantage in solving the problem of blind parameter estimation of non-cooperative high-order modulated PCMA signals. Simulation results show the performance of the proposed algorithm is similar to the modified Cramer-Rao bound (MCRB) when the signal-to-noise ratio is larger than 16 dB. The simulation results also verify the practicality of the proposed algorithm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.1324-1326
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• 2000

This paper proposes a Current-Fed Push Pull type DC-DC converter using LCCC Resonant circuit and Zero Voltage Switching function to reduce turn on and off loss at the switching instants. This paper have the advantage which is able to operating safely in load short, because of DC reactor is connected with resonance reactor in order to supply a fixed current with low ripple from DC Power supply. The capacitor ($C_1$, $C_2$) connected in switch are common using as resonance capacitor and ZVS capacitor. The analysis of the proposed Current-Fed Push Pull type DC-DC converter is generally described by using normalized parameter, and we have evaluated characteristic values which is needed to design a circuit. We confirm a rightfulness theoretical analysis by comparing a theoretical values and experimental values obtained from experiment using MOSFET as switching devices.

• 대한전자공학회논문지SD
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• 제47권2호
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• pp.32-39
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• 2010

기존의 셀 특성 분석은 다중 입력 변화를 고려하지 않고 셀 특성 분석을 수행한다. 다중 입력 변화가 시간적 근접성에 따라 게이트 지연 시간에 미치는 영향이 커지면서, 기존의 셀 특성 분석으로는 정확한 게이트 지연 시간을 예측하기가 어려워지게 되었다. 다중 입력 변화의 영향으로 인하여 게이트 지연 시간이 최대 46%까지 차이가 나는 것을 실험을 통하여 확인하였다. 본 논문에서는 다중 입력 변화의 시간적 근접성으로 인한 지연 시간 변화를 고려한 게이트 지연 시간 모델을 제안하였다. 제안된 모델은 Radial Basis Function (RBF)을 이용하여 지연 시간 변화량을 계산한다. 제안된 방법이 다중 입력 변화가 발생하였을 때, 보다 정확하게 게이트 지연 시간을 예측하는 것을 실험결과를 통하여 확인하였다.

• 한국조명전기설비학회지:조명전기설비
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• 제7권4호
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• pp.51-58
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• 1993

리니어 직류 모터의 고속, 고정도 위치제어에 대하여 포물선형 스위칭 함수에 최단시간 제어 방식을 제안하였다.제안한 방식은 간단한 구성으로 최단시간 제어를 실현한기 위하여 뱅-뱅 제어의 절환을 위상면에 설정한 포물선형 스위칭 함수상에서 행하는 것이다. 그러나 시스템의 모델링 오차등에 의하여 슬라이딩 모드를 발생시키므로 최단시간 제어를 위해 반복실험에 의하여 1회의 절환에 의한 뱅-뱅 제어를 실현하였다. 그 후 궤환 제어에 의하여 리니어 직류모터를 목표점에 정지시켰다.

• International Journal of Internet, Broadcasting and Communication
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• 제14권1호
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• pp.105-115
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• 2022

The platform for displaying cars has been changing with the times. From the popularity of paper media to the rise of computer graphics, the improvement of technology has brought more space and possibilities to the automotive industry. Yiming Zhong proposed the workflow of car configurator through Unreal Engine 4 to implement the basic functions of configuration in 2021, according to Yiming Zhong's final presentation, there is still room to improve the realism of graphics and functionality of the car configurator. Therefore, in this paper we propose to upgrade the car shaders and lighting environments according to the real-world physics and add multi-scenes switching function to car configurator. However the multi-scenes switching function also brings a large amount of data, which leads to the problem of display lag. At the end of the paper, we use the level of details(LOD) process to reduce the amount of data for real-time computing in Unreal Engine 4 and the increase of frames per second(FPS) values verifies the feasibility of our optimization solution.

• 한국통신학회논문지
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• 제22권6호
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• pp.1323-1333
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• 1997

In this paper, we propose an efficient architecture for a high-speed cell concentrator/distributor(HCCD) in an ATM(Asynchronous Transfer Mode) switch and by analyzeing the simulation results evaluate the performance of the proposed architecuture. The proposed HCCD distributes cells from a switch link to local processors, or concentrates cells from local processor s to a switch link. This design is to guarntee a high throughput for the IPC (inter-processor communication) link in a distributed ATM switching system. The HCCD is designed in a moudlar architecture to provide the extensibility and the flexibility. The main characteristics of the HCCD are 1) Adaption of a local CPU in HCCD for improving flexibility of the system, 2) A cell-baced statistical multiplexing function for efficient multiplexing, 3) A cell distribution function based on VPI(Virtual Path Identifier), 4) A bypassing capability for IPC between processor attached to the same HCCD, 5) A multicasting capability for point-to-multipoint communication, 6) A VPI table updating function for the efficient management of links, 7) A self-testing function for detecting system fault.

• 한국막학회:학술대회논문집
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• 한국막학회 1996년도 춘계 총회 및 학술발표회
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• pp.5-10
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• 1996

Active transport is one of the essential function of biological membrane transport systems, in which substrates are transported from lower to higher concentration side against their concentration gradient. In this article, we describe photo- and pH-induced active transport models by designing the functional carriers based on the affinity-switching strategy.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.999-1002
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• 1987

This paper describes the architecture and basic function of alarm system for the TDX-1A digital switching system. Also, it is shown that implemented software structure for alarm treatment employed in distributed control system TDX-1A.