• KIEE International Transactions on Power Engineering
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• 제11A권4호
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• pp.27-32
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• 2001

This paper presents a concept of reactive reserve based contingency constrained optimal power flow (RCCOPF). RCCOPF for enhancement of interface flow limit is composed of two modules, which are the modified continuation power flow (MCPF) and reactive optimal power flow (ROPF). In RCCOPF, two modules are repeatedly performed to increase interface flow margins of selected contingent states until satisfying the required enhancement of interface flow limit. In numerical simulation, a simple example with New England 39-bus test system is shown.

• Journal of Communications and Networks
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• 제1권3호
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• pp.201-212
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• 1999

This paper studies the rapid design and implementation of the medium access control(MAC) and related interface circuits for 802.11 wireless LANs based on the field programmed gate ar-ray(FPGA) technology. Our design is thus aimed to support both the distributed coordination function (DCF) and the point coordination function(PCF) with the aid of FPGA technology. Further-more, in an infrastructure network, some stations may serve as the access points (APs) which may function like a learning bridge. This paper will also discuss how to design for such application. The hardware of the MAC and interface may at least consist of three major parts: wireless transmission and reception processes and in-terface, host(bus) interface, and the interface to the distributed system (optional). Through the increasing popularity of FPGA de-sign, this paper presents how Complex Programmable Logic De-vices(CPLD) can be utilized for speedy design of prototypes. It also demonstrates that there is much room for low-cost hardware prototype design to accelerate the processing speed of the MAC control function and for field testing.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집A
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• pp.831-836
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• 2001

In the case of axisymmetric thermal analysis of drum brakes, the distribution of frictional heat produced on the interface and temperature difference between mating frictional faces are very interesting problems to computational researchers. In this paper, heat conduction from the interface to the pad and the drum was modeled by using a thin interface element, so artificial division of the generated frictional heat between pad and drum is not necessary. Temperature difference between mating frictional faces is successfully modeled by using the interface element. The influence of some parameters on tile thermal stress was checked. The analysis was performed by ABAQUS/Standard code.

• 센서학회지
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• 제18권6호
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• pp.409-416
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• 2009

A lot of valuable-piece of information are acquisited through ubiquitous sensor network(USN) system composed of man-made sensors. The telemetry system used for communicating to access informations between nature and human-beings monitors and estimates the status of infrastructure, utilities and natural environments to prevent hidden disasters, improving quality of life and productivity in multi-directional views. That would be the reason of USN subsistence. This paper will be a review on how to build long-term USN system. Therefore, this paper focuses on reviewing the sensor interface and the sensor network interface and its significance as the foundation stone for varying USN service profiles and showing its development example, and finally proposing a few of things to set up future-oriented USN open system.

• 대한전기학회논문지:전력기술부문A
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• 제50권2호
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• pp.83-89
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• 2001

This paper introduces a power flow model of SSSC for voltage stability analysis of power system installed with Static Synchronous Compensators. The SSSC model is obtained from the injection model of voltage source inverter by adding the condition that SSSC injection voltage is in quadrature with current of SSSC-installed branch. This model is incorporated into modified CPF algorithm to study effects of SSSC on the security-constrained interface flow limit. Determination of interface flow limit is simply briefed. In case study a 771-bus real system is used to show that interface flow limit can be improved by appropriate control of SSSC in terms of voltage stability.

• KIEE International Transactions on Power Engineering
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• 제11권X00호
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• pp.27-32
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• 2001

This paper presents a concept of reactive reserve based contingency constrained optimal power flow (RCCOPF). RCCOPF for enhancement of interface flow limit is composed of two modules, which are the modified continuation power flow (MCPF) and reactive optimal power flow (ROPF). In RCCOPF, two modules are repeatedly performed to increase interface flow margins of selected contingent states until satisfying the required enhancement of interface flow limit. In numerical simulation, a simple example with New England 39-bus test system is shown.

• 한국자동차공학회논문집
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• 제9권3호
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• pp.173-180
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• 2001

In the case of axisymmetric thermal analysis of drum brakes, the distribution of frictional heat produced on the interface and temperature difference between mating frictional faces are very interesting problems to computational researchers. In the first part, the influence of the s-cam load angles and elastic modulus of the pad on the contact pressure distribution between pad and drum was checked by a three dimensional model. In the second part heat conduction from the interface to the pad and the drum was modeled by using a thin interface element, so artificial division of the generated frictional heat between pad and drum is not necessary. Temperature difference between mating frictional faces is successfully modeled by using the interface element. The influence of some parameters on the thermal distribution is checked. The analysis was performed by ABAQUS/Standard code.

• 항공우주기술
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• 제9권2호
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• pp.57-62
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• 2010

저궤도 인공위성에서 SAR 위성 탑재체의 전류 소모량이 약 150A로 예측된다. 이러한 높은 전류 소모는 배터리-위성버스-탑재체로 이루어진 인터페이스에서 전압 강하를 유기하여 위성 본체의 전장품과 탑재체의 동작 전압을 낮추게 되어 정상 동작을 보장하지 못하게 된다. 따라서, 탑재체 동작에 따른 버스 전압과 탑재체 입력 전압 강하의 예측이 반드시 필요하다. 본 해석에서는 전압강하의 요인이 될 수 있는 하니스 및 접촉 저항에 대한 worst case analysis를 수행하여 탑재체 동작시 발생할 수 있는 전압 강하를 예측한다.

• 한국지능시스템학회논문지
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• 제11권8호
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• pp.764-770
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• 2001

본 논문에서는 대용량의 퍼지 데이터를 고속으로 전송 및 추론하기 위해 새로운 PCI 버스 기반 병렬 퍼지 시스템을 제안한다. 많은 퍼지 데이터의 고속전송을 위해 PCI 9050 인터페이스를 사용하고, 병렬 퍼지 추론 시스템을 위한 병렬 퍼지 모듈들을 FPGA로 설계하여 PCI 타겟 코어로서 병렬로 동작하게 한다. 여기서 소속함수들의 각 요소와 전건부 또는 후건부부분의 병렬화을 고려하여 제안된 시스템을 VHDL을 사용하여 설계 및 구현하였다. 제안된 시스템은 실시간에 고속의 퍼지추론을 요하는 시스템 또는 대용량 인공위성 영상 데이터의 패턴 인식 등과 같이 다수의 전건부, 후건부의 변수를 갖는 시스템에 활용될 수 있다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 A
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• pp.28-30
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• 2000

This paper introduces a power flow model of SSSC for voltage stability study. The SSSC model is obtained from the injection model of voltage source inverter by adding the condition that SSSC injection voltage is in quadrature with current of SSSC-installed branch. This model is incorporated into modified CPF algorithm to study effects of SSSC on the security-constrained interface flow limit. Determination of interface flow limit is simply briefed. In case study a 771-bus real system is used to show that SSSC can improve interface flow limit in terms of voltage stability.