• 한국정보처리학회논문지
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• 제6권4호
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• pp.1045-1057
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• 1999

패킷교환식 다단계 상호 연결 망은 디지털 교환시스템과 슈퍼 컴퓨터분야에서 널리 이용되어 왔다. 본 논문에서 교환 요소내부의 여러 개의 패킷이 한 네트워크 주기동안 그 주기의 대역폭을 충분히 사용함으로써 다음 단계의 교환 요소로 전송되어 질 수 있음을 보인다. 기존의 상호 연결 망에서는 보통 하나의 패킷 전송을 가정했다. 다중 패킷 전송방식이 도입된 다단계 상호 연결 망의 분석적 모델이 소개되고, 컴퓨터 시뮬레이션에 의하여 그 모델의 타당성을 입증한다. 단일 패킷 전송방식을 이용한 전형적인 다단계 상호 연결 망과의 비교는 실용적인 크기의 연결 망에 대하여 처리율이 약 30% 정도까지 증가함을 보여준다. 비슷한 결과가 지연시간에 있어서도 얻어진다. 네트워크 전송량이 불균등한 분포를 나타내는 경우의 성능 향상은 더욱 중요하다.

• Journal of Electrochemical Science and Technology
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• 제5권4호
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• pp.115-127
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• 2014

Cd-Pb thin films were electrodeposited from a diluted chloride solution using stainless steel rotating disc electrode. The linear sweep voltammograms of the single metallic ions show that electrodeposition of these ions was mass transfer control due to the plateau observed for different rotations at concentration (50 and 200 ppm). The voltammograms of binary system elucidate that electrodeposition process always start at cathodic potential located between the potential of individual metals. Currents transients measurements, anodic linear sweep voltammetry (ALSV) and atomic force microscopy (AFM) were used to characterize the electrocryatalization process and morphology of thin films. ALSV profiles show a differentiation for the dissolution process of individual metals and binary system. Two peaks of dissolution Cd-Pb film were observed for the binary system with different metal ion concentration ratios. The model of Scharifker and Hills was used to analyze the current transients and it revealed that Cd-Pb electrocrystalization processes at low concentration is governed by three-dimensional progressive nucleation controlled by diffusion, while at higher concentration starts as a progressive nucleation then switch to instantaneous nucleation process. AFM images reveal that Cd-Pb film electrodeposited at low concentration is more roughness than Cd-Pb film electrodeposited at high concentrated solution.

• 대한기계학회논문집B
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• 제24권3호
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• pp.338-345
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• 2000

A model testing has been performed to investigate the flow characteristics of a vortex chamber, which plays a role of a flow switch and passively controls the discharge flow rate. This method of passive flow control is a matter of concern in the design of advanced nuclear reactor systems as an alternative to the active flow control to provide emergency water to the reactor core in case of postulated accidents like LOCA (Loss-Of-Coolant Accident). By changing the inflow direction in the vortex chamber and varying the flow resistance inside the chamber, the vortex chamber can control passively the injection flowrate. Fundamental characteristics such as discharge flow rate and pressure drop of the vortex chamber are measured, and its parametric effects on the performance of the vortex chamber are also systematically investigated.

• 전기전자학회논문지
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• 제11권4호
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• pp.331-339
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• 2007

The problem of architecting a reliable transport system across an overlay network using split TCP connections as the transport primitive is mainly considered. The considered overlay network uses the application-level switch in each intermediate host. We first argue that natural designs based on store-and-forward principles that are maintained by split TCP connections of hop-by-hop approaches. These approaches in overlay networks do not concern end-to-end TCP semantics. Then, a new transport protocol-Overlay Transport Protocol (OTP)-that manages the end-to-end connection and is responsible for the congestion/flow control between source host and destination host is proposed. The proposed network model for the congestion and flow control mechanisms uses a new window size-Ownd-and a new timer in the source host and destination host. We validate our analytical findings and evaluate the performance of our OTP using a prototype implementation via simulation.

• 한국컴퓨터정보학회논문지
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• 제9권4호
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• pp.173-178
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• 2004

개방형 통신망에서 CVR, VBR, UBR, ABR과 같은 다양한 트래픽 관리 및 지연에 관한 연구가 진행되고 있고 특히 ATM망에서는 대역폭 확장 및 트래픽 관리를 통한 망의 효율적이며 유연한 품질 서비스를 제공한다. 이러한 품질 서비스를 제공하기 위하여 트래픽에 보안서비스가 제공되어야 하며 이에 대한 연구가 진행되고 있다. 본 논문에서는 ATM 보안 그룹에 들어오는 패킷들을 안정성 기준으로 평가하고 등급으로 분류하여 안전한 패킷은 통과시키고 비안전한 패킷은 폐기 또는 마크 패킷으로 통과 시킨다. 본 논문은 스위치에서 마크 패킷을 통과 시킬때 발생하는 패킷 지연에 관한 연구 및 시뮬레이션 시나리오를 제공한다.

• 제어로봇시스템학회논문지
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• 제13권8호
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• pp.743-748
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• 2007

Recently, various types of camera mouse are developed using the image processing. The camera mouse showed limited performance compared to the traditional optical mouse in terms of the response time and the usability. These problems are caused by the mismatch between the size of the monitor and that of the active pixel area of the CMOS Image Sensor. To overcome these limitations, we designed a new input device that uses the face recognition as well as the speech recognition simultaneously. In the proposed system, the area of the monitor is partitioned into 'n' zones. The face recognition is performed using the web-camera, so that the mouse pointer follows the movement of the face of the user in a particular zone. The user can switch the zone by speaking the name of the zone. The multimodal mouse is analyzed using the Keystroke Level Model and the initial experiments was performed to evaluate the feasibility and the performance of the proposed system.

• Journal of Power Electronics
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• 제12권3호
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• pp.410-417
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• 2012

In this paper, a direct current control method based on a one-cycle controller (DCOCC) for double frequency buck converters (DF buck) is proposed. This control method can make the average current through the high frequency and low frequency inductors of a DF buck converter equal. This is similar to the average current control method. However, the design of the loop compensator is much easier when compared with the average current control. Since the average current though the high frequency and low frequency inductors is equivalent, the current stress of the high frequency switches and the switch losses are minimized. Therefore, the efficiency of the DF buck converter is improved. Firstly, the operation principle of DCOCC is described, then the small signal models of a one cycle controller and a DF buck converter are presented based on the state space average method. Eventually, a system block diagram of the DCOCC controlled DF buck is established and the compensator is designed. Finally, simulation and experiment results are given to verify the correction of the theory analysis.

• Journal of Power Electronics
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• 제18권3호
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• pp.802-816
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• 2018

A digital direct phase-shift control (DDPSC) method based on the phase-shifted full-bridge LLC (PSFB-LLC) converter is presented. This work combines DDPSC with the conventional linear control to obtain a hybrid control strategy that has the advantages of linear control and DDPSC control. The strategy is easy to realize and has good dynamic responses. The PSFB-LLC circuit structure is simple and works in the fixed frequency mode, which is beneficial to magnetic component design; it can realize the ZVS of the switch and the ZCS of the rectifier diode in a wide load range. In this work, the PSFB-LLC converter resonator is analyzed in detail, and the concrete realization scheme of the hybrid control strategy is provided by analyzing the state-plane trajectory and the time-domain model. Finally, a 3 kW prototype is developed, and the feasibility and effectiveness of the DDPSC controller and the hybrid strategy are verified by experimental results.

• 한국디지털건축인테리어학회논문집
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• 제12권4호
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• pp.5-12
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• 2012

In this study, a digital design process by utilizing the program's database functionality in BIM, public education facilities master plan presented an alternative model to the layout of the design process. First of all, public education facilities master plan design process with digital design process and how to use the database of BIM in the process for review of the possibility of. Secondly, public educational facility planning the placement as needed for the switch to digital design limits, and the basic plan design at various elementary school planning alternatives in a school building and the school site is required to investigate. Thirdly, as a way of using the database features of GDL BIM lnn and teachers on how to create a variable by setting up a number of different alternatives so that you can choose the architect thought to have to organize and visualize the possibility of quick. A quantitative way the basic plan design that repeats some of the measures that can be used for digital design change as a process of continuous research is needed.

• 전력전자학회논문지
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• 제23권1호
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• pp.24-31
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• 2018

An induction heating (IH) resonant converter, as well as its coil design method, is proposed in this study to improve the heat capability of low- and high-resistance IH vessels. Conventional IH resonant converters have been designed only for heating high-resistance containers designed for IH application. Thus, the primary current in the resonant tank becomes extremely high to transfer the rated power when the converter heats the low-resistance vessel. As a result, the rated power cannot be transferred due to overcurrent flows against the rated switch current. Hence, the optimal number of coil turns and proper operating frequency to heat high- and low-resistance vessels are proposed in this study by analyzing an IH load model. Simulation and experimental results using a 2.4 kW prototype resonant converter and its IH coil validate the proposed design.