• 설비공학논문집
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• 제25권4호
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• pp.180-186
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• 2013

An electric vehicle is an environment-friendly automobile which does not emit any tailpipe pollutant. In a conventional vehicle with an internal combustion engine, the internal cabin of the vehicle is usually heated using waste heat from the engine. However, for an electric vehicle, an alternative solution for heating is required because it does not have a combustion engine. Recently, a heat pump system which is widely used for residential heating due to its higher efficiency has been studied for its use as a heating system in electric vehicles. In this study, a heat pump system utilizing air source and waste heat source from electric devices was investigated experimentally. The performance of the heat pump system was measured by varying the mass flow rate ratio. The experimental results show that the heating capacity and COP in the dual heat source heat pump were increased by 20.9% and 8.6%, respectively, from those of the air-source heat pump.

• 한국항공우주학회지
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• 제38권7호
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• pp.655-663
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• 2010

DUP(direct underside pressurization)는 위그선이 이륙하기 위하여 수면 위를 항주할때 낮은 속도에서 이륙할 수 있도록 양력을 증가시키는 역할을 한다. 이러한 DUP가 위그선의 안정성과 공기역학적인 힘에 미치는 영향에 관하여 3차원 수치해석을 수행하였다. 해석에 사용된 위그선인 "Aircat"은 동체의 중심에 프로펠러가 있고 동체하부에 공기부양실이 있으며 Lippisch형의 날개와 큰 T자형의 수평꼬리날개를 가지고 있다. 저속에서 대부분의 양력은 프로펠러에 의해 가속된 공기가 동체의 가운데 통로를 통하여 공기부양실로 들어가 정체됨으로써 발생한다. 그러나 DUP에 의해 가속된 공기는 동압의 증가로 인하여 항력을 증가 시킬 뿐만 아니라 안정성에 영향을 주게 된다.

• 한국전자통신학회논문지
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• 제14권2호
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• pp.361-368
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• 2019

본 논문은 전기차 기반의 1톤급 상용차용 통합공조 시스템에 관한 연구이다. 전기 상용차의 경우 화물의 승하차를 위해 문의 개폐가 빈번하게 이루어지기 때문에 열손실이 크게 발생한다. 따라서 냉난방 부하가 승용 전기차에 비해 더 크게 요구된다. 결과적으로 승객이 요구하는 열 쾌적성을 만족하기 위해서 냉난방 시스템이 소비하는 에너지가 승용 전기차 보다 크다. 이러한 단점을 극복하기 위해 효율적인 통합공조 시스템을 적용한 연구를 수행했다. 최종적으로 1톤급의 경상용 전기트럭의 상품성 개선과 전기트럭 분야의 산업 생태계 기반 확충을 위한 고효율 공조 시스템 개발을 위해 냉방을 위한 전동식 압축기와 난방을 위한 히트펌프 시스템의 구상 설계와 해석적 검증을 수행한다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제10권2호
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• pp.188-200
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• 2018

This paper proposes a single control strategy to solve the problem of trans-media vehicle difficult control. The proposed control strategy is just to control the vehicle's air navigation, but not to control the underwater navigation. The hydrodynamic model of a vehicle when entering water obliquely at low speed has been founded to analyze the motion characteristics. Two methods have been used to simulate the vehicle entering water in the same condition: numerical simulation method and theoretical model solving method. And the results of the two methods can validate the hydrodynamic model founded in this paper. The entering water motion in the conditions of different velocity, different angle, and different attack angle has been simulated by this hydrodynamic model and the simulation has been analyzed. And the change rule of the vehicle's gestures and position when entering water has been obtained by analysis. This entering water rule will guide the follow-up of a series of research, such as the underwater navigation, the exiting water process and so on.

• 한국컴퓨터정보학회논문지
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• 제23권12호
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• pp.11-19
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• 2018

In the Unmanned Aerial Vehicle Line-Of-Sight datalink system, there is a possibility that the communication line is disconnected because line of sight can not be secured by one antenna due to changes in position and posture of the air vehicle. In order to prevent this, both top and bottom of air vehicle are equipped with antennas. At this time, if the signal can be transmitted and received by switching to an antenna advantageous for securing the line of sight, communication disconnection can be minimized. The legacy antenna switching method has disadvantages such that diffraction, fading due to the surface or obstacles, interference and reflection of the air vehicle are not considered, or antenna switching standard is not clear. In this paper, we propose an airborne antenna switching method for improving the performance of UAV LOS datalink system. In the antenna switching method, the performance of each of the upper and lower parts of the mounted antenna according to the position and attitude of the air vehicle is predicted by using the deep learning in an UAV LOS datalink system in which only the antenna except the receiver is duplicated. Simulation using flying test dataset shows that it is possible to switch antennas considering the position and attitude of unmanned aerial vehicle in the datalink system.

• 한국자동차공학회논문집
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• 제7권9호
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• pp.20-27
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• 1999

The proportion of diesel vehicle is very high in this country . PM and NOx emitted from diesel-posered vehicle is severely ;affecting to be air quality . Especially, diesel particulate matters(DPM) including black smoke are hazardous air pollutants to human health and environment. In order to reduce the exhaust emissions from diesel engines, it is necessary to analyze the characteristics of exhaust emissions from diesel engines in various driving conditions. Recently, there are occasion to increase the fuel consumption rate to engine power up. So, in this study we have tested a diesel engine detached from in use -diesel vehicle and analyzed exhaust emission by driving condition and fuel dispersion rate. From this results, we will prepare the comprehensive management plan for exhaust emissions from diesel vehicles and contribute to the improvement of air pollution in urban area.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2010년도 춘계학술대회 논문집
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• pp.1131-1132
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• 2010

• 한국철도학회논문집
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• 제8권2호
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• pp.182-187
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• 2005

Air spring system was widely accepted for railway vehicle secondary suspension to reduce and absorb the vibration and noise. The low natural frequency ensures a comfortable ride and an invariably good stiffness. In this paper, the characteristics and durability test was conducted in laboratory by using servo-hydraulic fatigue testing system to reliability evaluation of air spring for electric railway vehicle. The experimental results show that the characteristics and durability of domestically developed productions are shown in good results. And to guarantee the adaption of air spring, the ride comfort and air pressure variation were measured in train test on subway line.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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• pp.270-273
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• 2011

Water management is important in proton exchange membrane fuel cell because the water balance has a significant impact on the overall fuel cell system performance. In fuel cell vehicle, the vehicle's power demand is dynamic; therefore, the dynamic water management system is required. This present study proposes a method to control the humidity of the input air in cathode side of the fuel cell vehicle. The simulation using several driving cycles shows the proposed air humidification control obtains a relatively good result. The liquid saturation level is seen constant at the target level although still there are small deviations at driving cycles which having averagely high power demands.

• 한국산업보건학회지
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• 제30권4호
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• pp.394-404
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• 2020

Objectives: The aims of this study are to derive the characteristics of diesel exhaust gas emissions generated during vehicle checking in the garage of fire stations and of the related improvement plans for proper air quality management. Methods: The researcher measured changes in the air quality inside garages according to the operating conditions of the exhaust facility and before and after vehicle checking at three fire stations. Results: During the checking of fire engines, a large volume of hazardous substances exceeding management standards were generated, and improvement of the discharge facilities was required for proper air quality management. Conclusions: It is necessary to study the hazard evaluation of firefighters' exposure to exhaust gas, to operate exhaust gas ventilation facilities, and to prepare technical standards for proper indoor air quality management.