• 항공우주시스템공학회지
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• 제16권3호
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• pp.35-41
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• 2022

UAM(Urban Air Mobility) 은 승객과 화물을 운반할 수 있는 새로운 형태의 안전하고 적합한 운송수단으로써 각광받고 있다. UAM 의 상업적인 사용은 2025년부터 시작될 것으로 예측되고 있다. UAM의 생산률은 기존 항공기 생산률보다 자동차 생산률에 더 가까울 것으로 예측되므로, 대량 생산 항공기에 대비한 새로운 인증 방안을 구축할 필요가 있다. 이러한 UAM은 구조물의 중량을 줄이기 위해 복합재료가 주 재료로써 사용될 것으로 예상되고 있다. 따라서 본 연구에서는 항공기용 복합재료 시범인증을 수행함으로써 국내 복합재료 인증 방안을 제시하고 인증소재를 소형 항공기용 부품에 적용하기 위한 연구를 수행하였다. 본 연구를 통해 대량생산이 필요한 UAM 항공기의 인증 시간을 절감할 수 있을 것으로 예상한다.

• 한국항행학회논문지
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• 제27권3호
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• pp.262-268
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• 2023

2025년을 목표로 UAM을 상용화하겠다는 정부의 의지를 바탕으로 국가기관과 전 세계 기업을 중심으로 UAM 기체 개발을 포함한 여러 분야에서 놀라운 성과를 이뤄내고 있다. 또한 최근에는 도심항공모빌리티(UAM) 개념을 기반으로 도심 항공 운용과 관련이 없는 장거리 또는 근거리 도시 간 상용운용, 화물배달, 공공 서비스, 항공 관광, 개인/레저용 기체와 같은 사용을 포함하는 선진항공모빌리티(AAM; Advanced Air Mobility) 개념으로 진화하고 있다. 이처럼 UAM 산업이 기체 개발, Vertiport 설계 및 구축, 항행시스템 등의 다양한 분야에서 활성화되고 있지만, UAM을 이용한 승객 이동 시 저고도 운항 특성과 3차원 내에서의 속도감, 외부 환경에 의한 기체 흔들림 등으로 인한 승객의 공포심과 어지러움 등 신체적 문제에 관한 연구는 지금까지 거의 찾아볼 수 없는 상태이다. 따라서 본 연구에서는 헬리콥터를 활용하여 UAM의 예상 고도와 속도로 비행하면서 실제 영상을 촬영, VR과 Motion이 장착된 UAM 시뮬레이터를 활용하여 일반인들에게 체험함으로써, 추후 UAM 실제 운항 시 발생할 수 있는 승객들의 공포심과 어지러움 등의 신체적 반응을 확인하고, 문제점을 분석하고자 한다.

• 수산해양기술연구
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• 제51권3호
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• pp.333-339
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• 2015

Fish exportation using airplanes incurs sizable logistics costs (12,000KRW/kg), according for more than 45% out of the total export cost. Thus, it is unreasonable to quantitatively expand fish exportation by means of air transport. In addition, cases of failing to deliver fish at the right time to the right place occurs frequently due to the limited cargo capacity and insufficient cargo space of airplanes, especially during the peak season. Therefor, a technology that not only minimizes the logistics costs but also transports fish freshly and safely, in the case of long distance exportation to countries such as the United States and Taiwan, should be developed. In this study, a live fish container control system for long distance transportation was designed and implemented. Live flatfish (2,000kg) were selected as the target fish, were transported to the United States to analyze and verify the performance of the a live fish container control ystem and transportation ability.

• 대한조선학회논문집
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• 제35권4호
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• pp.27-37
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• 1998

선박이 대형화되고, LNG선의 건조가 활발해지면서 액체화물탱크의 내부유동을 뜻하는 슬로싱에 대한 연구가 중요해지고 있다. 슬로싱에 의한 충격압력의 크기와 특성을 파악하기 위하여 직사각형 모델에 대한 체계적인 실험을 수행하여 회전각, 동요주파수, 적재수심에 따른 내부유동의 특성을 분석하였고, 충격압력이 가해지는 탱크벽면의 구조응답을 계측하여 유탄성효과를 고찰하였다. 탱크의 내부유동은 고차경계요소법을 이용하여 해석하였고, 평판의 진동에 의해 유기되는 유체력은 고유함수 전개법을 이용하여 부가질량과 감쇠력으로 표현하였다. 충격하중이 작용하는 경우 유탄성 효과를 고려한 탱크 벽면은 부가질량의 영향으로 그 때의 수심에 해당하는 접수진동수로 진동하였고, 벽면에서 압력은 유탄성효과를 고려하지 않은 경우에 비해 두 배 이상 크게 나타났다. 이를 실험과 계산에서 모두 확인하였고, 충격하중에 의한 평판의 거동에서 유탄성효과를 규명하였다

• 도시과학
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• 제11권2호
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• pp.45-54
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• 2022

Recently, regulations on automobile exhaust gas emission are being strengthened. Accordingly, automobile exhaust gas emissions are expected to decrease and continue to decrease. On the other hand, many countries do not yet consider the emission of non-exhaust air pollutants from automobiles as important. Automobile non-exhaust substances are classified into three categories: tire dust emissions, brake wear emissions, and road scattering dust. In particular, in the case of tire dust, research results exist that pollutant emissions increase as the weight of a vehicle increases. Since the weight of trucks varies according to the load and the load along the axles is also different, it can be expected that the emission of PM10 from the tire dust will be different depending on the loading method. Therefore, this study was conducted on the amount of PM10 generated in tire dust considering the axle load of the truck according to the loading method. However, it was confirmed that the total amount of PM10 was less than that all loads are loaded in the front or rear when the load was evenly distributed in the front and rear of the cargo compartment. In particular, if the load is distributed evenly in the front and back of the cargo compartment and the load in the front part is divided into 2 to 6 and loaded, as the number of divided loading increases the amount of PM10 generated decreases. And when the load is divided into 6 pieces, the total amount of PM10 generated is 0.3952g, the minimum value. If the load is divided into 6 or more and loaded evenly, the total PM10 generated continuously increases and converges to about 0.3964g.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.986-993
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• 2011

The role of brake is safely to transport passenger & cargo and stop vehicles at emergency in railway vehicle. Brake system reduces the speed by control command of electricity or air. mechanical methods to perform brake are disk brake & tread brake. This study targeted development of highly efficient sintered alloy brake shoe in railway vehicle whose high frictional coefficient, wear resistance, compatibility of the existing tread brake shoe & minimization of wheel's thermal damage and performed development of friction material's formulation, analysis of pressure distribution in wheel tread & brake shoe, optimum form design through analysis of heat flow.

• 한국항해항만학회지
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• 제33권4호
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• pp.283-288
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• 2009

To improve maritime security and enhance international shipping commerce within US ports in addition to ISPS (International Ship and Port Facility Security Code), the TWIC (Transportation Worker Identification Credential) program is working on the maritime field from the October 15, 2008 in the United States. In this paper, the program is reviewed and investigated in terms of goal, benefit, solution, and related legislation so forth In addition, other maritime security programs including MMD (Merchant Mariner Document), FAST (Free and Secure Trade), SIDA (Security Identification Display Areas). and Air Cargo security program was analyzed and compared in order to obtain relationship and difference with the program in terms of enrollment frequency, list and method of security check, and profile of each program As a result of this paper, the program is mostly to improve maritime security, protect individual privacy, and enhance commerce rather than other programs.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.570-573
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• 2004

We proposed a new system to collect hyperspectral data using a general cargo crane. The system has advantageous characteristics for precise data collection and analysis. In order to evaluate the validity, we performed the system on actual rice paddy field and analyzed the observed data. On the process, we could successfully extract the pure vegetation spectrum with high stability. The data taken by the system are useful for detail analysis among fields. In future development, it can be used for obtaining the grand truth for calibrating satellite or aerial hyperspectral images.

• 통상정보연구
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• 제6권3호
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• pp.183-201
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• 2004

Recently, Electronic commerce market is growing sharply for the expansion of internet and development of means of air transportation. Import Clearance System for express consignments, introduced in Korea, confers some benefit upon express consignments, ie. prompt clearance, simplification of the clearance procedure, exemption of necessary documents. But it has some problems such as lack of social security and trade compliance. So it requires some improvements as follows. Firstly, it has no legal background to clear all articles valued at US$100 or less carried by an express consignment operator. So customs brokers, not express consignment operators, should clear that articles. Secondly, it should be presented necessary documents including commercial invoice to prevent a wrong price declaration in entering express consignments valued at US$100 or less. Thirdly, X-ray inspectors must enhance their inspection ability. Customs must provide education programs for X-ray inspectors to improve their inspection ability. Lastly, Cargo selectivity system for express consignments have to be improved to operate effectively.

• Journal of Advanced Marine Engineering and Technology
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• 제11권1호
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• pp.39-52
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• 1987

Recently, the design problem of heat insulation have been reappraised in the aspect of energy saving due to the rising trend of energy cost. For example, that design problem is increasingly requsted in the fields of accommodation air conditioning systems, hot water supply systems, cargo handling systems, district heating or cooling systems. The rational design of heat insulation of piping systems can not only improve the overall efficiency of energy transfer but also give energy saving. In this paper, the heat insulation problem of district heating systems is therefore modeled as the multi-stage decision processes, suitable for dynamic programming technique. And take the object function as the sum of heat insulation material cost involved construction cost and heat loss cost, and propose the design method to minimize the object function for overall piping systems by dynamic programing. Effectiveness of design method presented here is proved by a computer simulation.