• Aerospace Engineering and Technology
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• v.2 no.1
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• pp.11-21
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• 2003

This paper deals with preliminary design results of autopilot for station keeping mode of airship. Linear equations of motion for the airship are derived. Basic architecture of the control laws for cruising and station keeping modes are proposed. Performance analysis results show that autopilot design for station keeping mode of airship is feasible.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.05a
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• pp.361-363
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• 2013

비파괴 검사란 재료나 제품을 원형과 기능에 변화를 주지 않고 실시하여 원하는 정보를 획득할 수 있는 검사를 의미한다. 비파괴검사는 점검자의 육안 조사를 통한 수작업으로 이루어지고 있기 때문에 점검자의 주관이 개입되며, 점검자에 따라 검사 결과의 차이가 있을 수 있으므로 신뢰도의 차이가 발생하게 된다. 그러므로 본 논문에서는 비파괴 검사를 이용하여 획득한 세라믹 소재 영상에서 효율적으로 결함을 검출하는 방법을 제안한다. 제안된 방법은 세라믹 소재 영상에 가우시안 필터링 기법을 적용하여 잡음을 제거하고, Ends-in Search Stretching 기법을 적용하여 명암 대비를 강조한다. 명암 대비가 강조된 영상에 샤프닝 기법을 적용하여 윤곽선을 강조한다. 윤곽선이 강조된 영상에 $3{\times}3 $ Roberts 마스크를 적용하여 강조된 윤곽선을 추출하고, Glassfire 기법을 적용하여 라벨링한 후, 시그마 퍼지 이진화 기법과 형태학적 정보를 이용하여 잡음을 제거하고 결함 영역을 검출한다. 제안된 방법을 세라믹 소재 영상을 대상으로 실험한 결과, 효율적으로 결함을 검출하는 것을 확인할 수 있었다.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1423-1425
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• 2000

경부고속전철(KTX)의 운행은 서울-동대구간은 고속선에 의한 고속 운행을 실행하는 반면, 동대구-부산간은 기존선 전철화 및 선로 개량 사업을 통해 기존선을 운행한다. 그 결과 남서울, 북대전, 남대전, 및 북대구의 기존선과 고속선 연결부 인터페이스는 가장 중요한 검토 및 연구 대상으로, 기존선과 고속선 간의 속도 형상에 대한 호환성은 KTX 차량의 적절한 운행을 결정하는 기본 요소이며 또한 필수 요소로 작용한다. 따라서 본 연구에서는 기존선과 고속선 신호 시스템의 호환성에 따른 속도 천이를 분석한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2410-2416
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• 2016

Recently, most countries in the world have pursued a denuclearization. So it has been of interest to increase to Nuclear weapon in such as North Korea's continued nuclear test. Pulsed gamma rays produced in the nuclear explosion and the space environment can give the big damage to the electronic device in a very short period of time. To confirm the extent of damage of these electronic devices, pulsed gamma irradiation facility that can occur in nuclear weapon or space environment are required. In this paper, we implemented the pulsed gamma-ray detection module and analyzed output of the irradiation test. We have experimented using an electron beam accelerator research facilities in Pohang Accelerator similar conditions to equip and Nuclear weapon. As a result, we confirmed that the pulsed gamma rays emitted by the gamma radiation and electron beam conversion device. The results of this paper will contribute to improve the reliability and accuracy of studies for utilizing pulsed gamma rays.

• Proceedings of the Korea Contents Association Conference
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• 2004.05a
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• pp.377-384
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• 2004

The field based morphing requires the user to set most of the control lines manually which requires much time and skill to get satisfactory results. This thesis proposes a method to acquire semi-automation of image morphing through first acquiring shape information from the source image and the target image, then after the user manually designates the least amount of a pair of feature points, these are used as standards for polygon based vertex search to set the appropriate control line to the source mage and target image, and then using the ratio of control line lengths and space. Using the proposed method, the user can reduce the time setting the control line and unskilled persons can get natural image morphing results while designating the least amount control line.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.470.1-470.1
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• 2014

InAs는 high mobility를 갖는 III-V 화합물 반도체로 최근 InAs 나노선 기반 electronic transport에 대한 연구가 활발히 진행되고 있다. 또한, InAs는 n-type의 중온 영역대의 열전물질로서 나노선이나 나노박막과 같은 저 차원 구조의 열전 특성에 대한 보고가 이루어 지고 있다. 대부분의 InAs 나노선의 성장 방법은 화학기상증착법에 의한 것으로, 상온에서 $100{\mu}V/K$ 이하의 낮은 Seebeck 계수 값을 나타내고 있다. 본 연구는 무촉매 상태에서 MBE (Molecular beam epitaxy) 성장시킨 InAs 나노선의 열전 특성을 측정하였다. MTMP (Microfabricated Thermoelectric measurement platform)를 이용하여 50 K에서 300 K까지의 온도 영역에서 전기전도도, Seebeck 계수의 측정을 진행하였다. 그 결과 Seebeck 계수 값은 상온에서 대략 $200{\mu}V/K$로 높게 나타나고 있으며, 동일한 나노선의 상온 전기전도도는 대략 9800 S/m로 많은 보고들과 비슷한 수준의 수치가 나타나고 있다. Transconductance 측정을 통한 field-effect mobility와 carrier 농도를 평가한 결과가 Mott formula에서 계산된 carrier 농도와 유사한 결과를 나타내었다. 매우 큰 Seebeck 는 carrier 농도가 낮은 것에 기인한 것으로 판단된다.

• Journal of Digital Contents Society
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• v.5 no.4
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• pp.269-274
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• 2004

The field based morping requires the user to set most of the control lines manually which require much time and skill to get satisfactory results. This tjesis proposes a method to acquire semi-automation of image morphing through first acquiring shape information from the source image and the target image, than after the user manually designates the least amount of a pair of feature points, these are used as standards for polygon based vertex to set the appropriate control line to the source image and target image, and then using the ratio of control line lengths and space. Using the proposed method the user can reduce the time setting the control line and unskilled persons can get natural image morphing results while desingnating the least amount of control line.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.6
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• pp.598-604
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• 2011

A method of miniaturizing branch line coupler with connected coupled lines is presented. The quarter-wavelength transmission lines in the typical microstrip branch line coupler are replaced with the connected coupled lines with same characteristics of ones for compact size. The connected coupled line is analyzed by T-equivalent circuit and Z parameters based on the even-odd mode analysis. The proposed branch line couplers with connected coupled line are designed and fabricated on FR4 substrate at 2.4 GHz. The measured results show good agreement with theoretical prediction. And the experimental results show that the size of coupler is 37 precent smaller than conventional coupler. This minimized coupler is suitable for Butler Matrix as feeder for mobile communication beam forming antenna.

• Food Science and Preservation
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• v.20 no.1
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• pp.45-51
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• 2013

This study was conducted to evaluate the changes in the quality of rice wine (Makgeolli) treated with UV-C and electron beam (EB) irradiation during its storage at $4^{\circ}C$ for 15 days. The EB irradiation was found to be more effective than the UV-C irradiation for microbiological control. The pH tended to be increased by UV-C, EB irradiation, and storage period. Acidity was significantly higher in rice wine treated with EB irradiation than those of control and UV-C irradiation during storage period. The $L^*$-value of the samples treated with UV-C and EB irradiation tended to be proportionately higher than that of the control, but this was not consistent during storage period. The $a^*$-value of the sample treated with EB was higher than that of the others, but this was not consistent during the storage period. The reducing sugar content was higher in the control at day 0, but it rapidly decreased compared with the control during the storage. The results indicate that EB irradiation was more effective than UV-C irradiation in controlling microorganisms of rice wine. However, a further study is needed to minimize the rice wine quality deterioration caused by UV-C or EB irradiation during storage.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2021-2022
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• 2006

Power-Line Communication (PLC)는 전력선을 채널로 이용한 통신 방법으로 별도의 전용선 설치 없이 통신이 가능한 기술을 말한다. 그러기에 오래전부터 연구가 진행되어 왔으며 최근에도 여전히 고속 전력선 통신에 관한 연구가 진행 중에 있다. 이에 본 논문에서는 이런 고속 전송을 위해 최근 연구가 활발한 고속 Ultra Wide Band (UWB) 전송기술을 전력선 통신에 적용하여 시뮬레이션한 후 결과를 통해 적용가능성을 확인한다.