• 한국지열·수열에너지학회논문집
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• 제9권4호
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• pp.1-7
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• 2013

This study is to compare energy consumption of air-source, ground-source and dual-source heat pump systems during intermediate season using dynamic simulation. Ground-source heat pump has higher COP than that of air-source but requires additional power consumption of auxiliary equipment such as circulation pump. During intermediate season when the outdoor air temperature is favorable, total COP of air-source heat pump may be greater than that of ground-source when circulation pump power consumption is included. Dual-source heat pump which selects the more favorable heat source is compared with air-source only and ground-source only heat pumps for total power consumption. Results show that power consumption of dual-source heat pump is lower than that of ground-source only by 0.73%.

• 제어로봇시스템학회논문지
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• 제16권2호
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• pp.101-106
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• 2010

Researches on air-ground robot cooperating system has been made recently. The cooperation among homogeneous robots focused on the architecture of the system, quality and influence of the communication. In contrast, the cooperation among heterogeneous robots such as aerial vehicle and ground vehicle robots has not been much handled. There are a couple of main points for those air-ground cooperating robots. One is using UAV (Unmanned Aerial Vehicle) as an extra sensor of UGV (Unmanned Ground Vehicle). This kind of application is usually used in situations such as guiding UGV to an appropriate path which could be better determined from the eye in the sky as UAV. The other main application of air-ground cooperating robot system is the localization. By combining sensor information from both UAV and UGV, the robot system as a whole can localize a target object or find features in the environment with better performance than UGV or UAV alone. Although these applications are recently studied in many different ways and devices, there are still a lot of possibilities in the field of air-ground cooperating robot systems. We introduce those research fields in this paper.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.177-180
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• 2001

A decoupled, wide-band, perfectly magnetically conductor(PMC)-backed air waveguide antenna is designed and constructed for the use of the continuous electromagnetic wave ground penetrating radar in the frequency range from 200MHz to 600MHz. Two planar dipoles are located inside air slab covered by PMC on the top side and separated by an air gap from the bottom ground interface. The coupling between the transmitting and the receiving dipoles is calculated by less than -60dB over the frequency from 200MHz to 600MHz.

• 한국지열·수열에너지학회논문집
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• 제12권2호
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• pp.1-6
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• 2016

A ground air heat exchanger (GAHX), also called earth air heat exchanger is a useful technology to be integrated with other renewable energy technologies. In this study, ground-air heat exchanger system for the air source heat pump is introduced. The purpose of this study is to design the volumetric flow rate and the length of GAHX system. A GAHX length model equation has been developed and used for calculation. GAHX thermal efficiency are recommended as 75% and 85% in order to optimize pipe length. $2,750m^3/h$, $2,420m^3/h$ of volumetric flow rate on 88.3m, 111.7m length are suggested for providing 7.5kW thermal capacity. And the number of path is recommended more than two to minimize pressure drop. For future study, advanced model equation study with ground thermal behavior and a more efficient GAHX design will be considered.

• 한국조경학회지
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• 제24권1호
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• pp.65-78
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• 1996

To study the temperature mitigation effects from urban green, several arrangements of green spaces were selected and air/ground temperatures were measured in Chongju city area. The results of this study can be summarized as follows; 1. It was found that the natural ground materials effect more affirmatively on the air and ground temperature than artificial ones do. The best results were recorded from the grass surface presenting highest mitigation effect and lowest daily temperature deviation. 2. Temperature mitigation effects of Tree-Shade on ground are different from season, ground material, and crown-size. Them most effects were found in interlocking block, the least in grass surface among recorded 2 seasons and 3 materials. In case of air temperature, the effects were more or less decreased in most cases. 3. From the survey, it was confirmed that the smaller urban greens can do its role of temperature mitigation as larger ones does. In case of this study, the effect was recorded about 2.3$^{\circ}C$.

• 한국추진공학회지
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• 제19권6호
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• pp.81-90
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• 2015

램제트 엔진, 스크램제트 엔진과 같은 극초음속 공기흡입식 추진기관을 지상에서 시험하기 위해서는 극초음속 추진기관이 작동하는 고고도, 고 마하수 환경을 모사해야 한다. 따라서 고압, 고온 환경을 조성하여 고고도 고 마하수 환경을 지상에서 구현해야 한다. 본 논문에는 한국항공우주연구원에서 설계 및 제작한 극초음속 공기 흡입식 추진기관 지상 시험설비의 구성과 특성에 대하여 소개한다.

• Journal of Korean Society for Atmospheric Environment
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• 제19권E2호
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• pp.83-88
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• 2003

The present study details air pollution measurements in the Yellow Sea of East Asia. Large-scale air pollution was observed through satellite images and ground monitors in Chongju-Chongwon of central Korea. Evidence of a duststorm transport and resulting dustfall from the Gobi Desert in north China and Mongolia is shown. Also, transport of anthropogenic air pollutants from China to the Yellow Sea, Korea, and Japan was detected and discussed. It was found that the level of air pollution concentrations at a regional back-ground site increased 2 ∼ 4 times than the values observed with the relatively clean air, when massive air pollution from China moved to the Korean Peninsula. Satellite measurements will be useful for monitoring regional- and global-scale air pollution in the future.

• 한국군사과학기술학회지
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• 제25권3호
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• pp.267-274
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• 2022

The Republic of Korea has a close cooperative relationship with NATO, of which the United States is a member. NATO is encouraged to follow UHF coalition waveforms for military air operations(SATURN) as defined in STANAG 4372. SATURN is a high-speed frequency hopping waveform with enhanced anti-jamming and security functions. Plans to improve the performance of existing military aircraft with air to ground radios to which SATURN function is applied. IFF case analysis and MRT evaluation plan were established to present an efficient test and evaluation plan for air to ground radios.

• 한국지열·수열에너지학회논문집
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• 제15권2호
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• pp.10-16
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• 2019

In this study, the present regulation of heat metering for the ground source heat pump was investigated. The ground source heat pump has been adopting the heat metering system used in the district heating system for estimating the heating and cooling energy production amount. The accuracy of the present heat metering systems for a water to water ground source heat pump is low, because the system for district heating has a relatively high temperature range comparing with the ground source heat pump operating conditions. Even though the heat amount for the building side should be measured, the heat absorption and extraction amount from or to the ground was measured for the water to air ground source heat pump due to the difficulty of estimating the air side heating and cooling capacity in the present regulation. It is highly recommended to validate the heat metering system to have reliability for the ground source heat pump and develop the system to be applicable water to air ground source heat pump.

• 한국군사과학기술학회지
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• 제15권3호
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• pp.306-314
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• 2012

This paper proposes a new system to maximize efficiency of Air Base Protection Operations through the development of location identification software. The Wibro-based location identification system for Air Base Protection Force offers Blue Ground Force digitalized character message which is not exposed to enemy. Also, it is possible to automatically provide the location of Blue Ground Force to Air Base Ground Operations Center. The test result proves that this system is very helpful when Air Base Protection Force executes Air Base Protection Operations.