• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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• pp.93-96
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• 2008

본 연구에서는 multi-port를 가진 하이브리드 연료의 포트간 병합특성에 관하여 수행하였다. 연료는 4 또는 5 port를 갖는 PE(Poly Ethylene), 산화제는 GOX를 사용하였다. port수에 따른 병합 특성에 대해서 연구하였다. Multi-port는 연소 중에 포트간 병합이 되어 연소 면적의 변함에 따라 로켓의 성능에 영향을 미친다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제31회 추계학술대회논문집
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• pp.247-250
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• 2008

본 연구에서는 Multi-Port 그레인의 PE, PMMA 연료와 GOX 산화제를 적용한 하이브리드 로켓의 연소 특성과 연소가 진행됨에 따라 이루어지는 연료 포트 병합에 따른 연소 특성을 연구하였다. 연료 내부로의 열전도와 연소실 압력의 증가로 인해 Multi-Port 연료의 후퇴율이 Single-Port 연료의 후퇴율보다 높으며, 연료 포트 병합으로 인한 연소 면적의 급격한 변화가 연소 성능에 영향을 끼침을 확인하였다.

• Journal of Information Processing Systems
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• 제19권4호
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• pp.407-416
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• 2023

In order to effectively relieve the traffic pressure of the city, ensure the smooth flow of freight and promote the development of the logistics industry, the selection of appropriate port logistics location is the basis of giving full play to the port logistics function. In order to better realize the selection of port logistics, this paper adopts the entropy weight method to set up a multi-dimensional evaluation index, and constructs the evaluation model of port logistics location. Then through the actual case, from the environmental dimension and economic competition dimension to make choices and analysis. The results show that port d has the largest logistics competitiveness and the highest relative proximity among the three indicators of hinterland city economic activity, hinterland economic structure, and port operation capacity of different port logistics locations, which has absolute advantages. It is hoped that the research results can provide a reference for the multi-dimensional selection of port logistics site selections.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제29회 추계학술대회논문집
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• pp.256-259
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• 2007

하이브리드 로켓의 원통형 multi-port 그레인에서 그레인 포트 개수 변화에 따른 연소특성을 고찰하였다. 후퇴율의 경우 그레인 포트 개수가 증가할수록 연료 포트 후퇴율과 끝단면 후퇴율 모두 증가하였다. 성능변수의 경우 그레인 포트 개수가 증가할수록 O/F 비는 낮아졌고, 비추력은 높아졌다.

• 한국항공운항학회지
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• 제15권4호
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• pp.17-23
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• 2007

This paper describes the flow and performance characteristics inside the post-chamber of the multi-port hybrid rocket motor. Using the computational fluid dynamics (CFD) technique, the non reactive compressible flow fields in the downstream of the fuel grain was numerically calculated. The motor performance obtained from computational results were in agreement with that conducted by the ground motor firing test. Besides, the flow field characteristics inside the post-chamber were discussed under different port numbers (1 port and 3 ports) of the fuel grain. The flow pattern showed that the performance of multi-port hybrid rocket motor having three grain ports is higher than that of the single-port one due mainly to the difference of incoming mass flow rate irrespective to the pressure field.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권6호
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• pp.589-593
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• 2013

An efficient measurement methodology is proposed to construct the scattering parameters of a multi-port device using a four-port vector network analyzer (VNA) without the external un-terminated ports. By using the four-port VNA, the reflected waves from the un-terminated ports could be minimized. The proposed method significantly enhances the accuracy of the S-parameters with less number of measurements compared to the results of classical renormalization technique which uses two-port VNA. The proposed method is validated from the measured data with the coupled 8-port micro-strip lines.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
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• pp.79-83
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• 2003

Multi-port($2{\times}2$port, 1port) rectangular waveguide discontinuity problem has been analyzed by use of $TE^x_{mn}$ (mono)mode matching method. Matrix size can be reduced significantly in comparison with $TE_{mn}&TM_{mn}$(full-wave)mode matching method. the present results is compared with those by CST MicroWave Studio to validate the presint method.

• 해양환경안전학회지
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• 제25권3호
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• pp.251-258
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• 2019

This study was conducted to propose an effective port operation method in terms of the design capacity of waiting anchorage by comparing the ratio and the number of waiting anchorage according to the port operation method of Busan New Port. For this, the Arena simulation program compared the rates of waiting vessels according to the application of the multi-user terminal, liner terminal and hybrid liner terminal operation methods. As a result, analysis suggested the necessary anchorage space can be reduced to about 18 % when using the multi-user terminal operation method and about 15.6 % when using the hybrid liner terminal operation method, as compared with the liner terminal operation method. Specifically, it was effective to apply the multi-user terminal operation method in terms of the anchorage capacity to be designated to Busan New Port. This study can apply to the designation of the new anchorage in the Busan New Port by reflecting the contents of the design of the anchorage in accordance with the port operation method.

• 한국정보통신학회논문지
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• 제14권12호
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• pp.2615-2621
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• 2010

본 논문에서는 메타물질 구조 다중대역 6단자 위상상관기를 설계하고 제작하였다. 이중 주파수 대역에서 신호를 수신 처리할 수 있는 집중소자형 메타물질 구조를 해석하고, 해석된 결과를 기반으로 다중대역 직접변환 수신 전처리기에 적합한 소형화 메타물질 구조 6단자 위상상관기를 제안하고 구현하였다. 다중대역 6단자 위상상관기를 구성하는 저항성 전력 분배기와 메타물질 $90^{\circ}$ 하이브리드 결합기의 산란 계수를 기반으로 동일한 특성을 갖는 6단자 위상상관기 구성 요소를 제작하고 측정하였다. 측정된 메타물질 구조 6단자 위상상관기는 모의실험 결과와 일치하였으며, 이중 주파수 대역에서 -20 dB 이하의 정합과 1 dB 이내의 전달 이득차, 그리고 ${\pm}4.1^{\circ}$ 이하의 전달 위상차 특성으로 양호한 다중대역 6단자 위상상관기 성능을 나타내었다.

• 한국항공운항학회지
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• 제15권4호
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• pp.38-44
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• 2007

This paper describes the structural safety of solid fuel in the Hybrid Rocket Motor (HRM). Hybrid rocket combustion has the distinct regression characteristics which include the process of thermal pyrolysis and fuel vaporization. Most of all, this regression characteristics would structurally affect the strength of the fuel having a multi-port configuration, and even may cause the breaking from the fuel grain. This problem would probably influence the performance and operating safety of HRM. Therefore, for the safe operation of HRM, the critical port radius which determines the structurally safe region was discussed from the heat analysis of the solid fuel.