• 설비공학논문집
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• 제14권7호
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• pp.560-566
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• 2002

The fault detection and diagnosis technology may be applied in order to decrease the energy consumption and the maintenance cost of the air-conditioning system. In this study, two different types of faults in the air-conditioning system, such as the condenser fouling and the evaporator fan slowdown, were considered. The neural network algorithm combined with data preprocessor was developed and applied to detect the faults of the real system. Test results show that this method is very effective to detect the faults in the air-conditioning system. Therefore, this developed method can be used for the development of the air-conditioner fault detection system.

• 한국농림기상학회지
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• 제22권3호
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• pp.171-175
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• 2020

대기오염의 사회경제적 효과에 대한 연구에는 측정된 대기오염 물질, 기상 자료, 그리고 사회경제적 데이터의 병합이 필요하다. 이들 자료들의 시간적·공간적 범위와 단위가 상이하기 때문에 분석에 필요한 데이터 가공에 많은 시간과 노력이 요구된다. 본 데이터의 구축은 사회과학 분야에서 널리 사용되는 대표적인 대기오염 및 기상 변수를 시군구 단위로 제공하는 것을 목표로 한다. 2020년 8월 기준 배포 버전 데이터의 시간적 범위는 2001년부터 2018년이며, 공간적 범위는 250개 시군구로서 패널 형태의 자료를 제공한다. 본 데이터의 기상 변수들은 대기오염 관련 분석뿐만 아니라 다양한 사회과학의 연구에서 사용할 수 있는 주요 변수들을 포함하고 있다.

• 한국대기환경학회지
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• 제15권6호
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• pp.813-826
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• 1999

To understand the present status of air pollutant emission data for the greater Seoul area, existing air pollutant emission data were analyzed and compared. For the criteria pollutants, estimation methods of emissions from point, line, and area sources adopted in the previous studies were analyzed and their results were compared. Two sets of VOC emission estimation were also compared and analyzed. There exists a large discrepancy among previous emission data due to the differences in the scope of emission sources and the estimation method including emission factors employed in each estimation. Applications of previous air pollutant emission studies for air quality modeling and related problems were discussed.

• 한국군사과학기술학회지
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• 제12권2호
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• pp.175-181
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• 2009

All of the military aircrafts in Korea Air Force are administered and operated together in the same system regardless of whether they are equipped with the data communication capability or not. The absence of the data communication capability in some of the aircrafts might increase whole kill chain hour at the point of the Network Centric Warfare achievement. Network synergy effects cannot also be desired if the section which is not connected to the network influences to the whole tactical network. Equipping aircrafts with the data communication capability could be done by upgrading the aircrafts, but resulting in high costs and long updating time. This paper is a research about the design and implementation of the UMPC based Data Link System to aircrafts that do not have the data communication capability. The proposed system grafts the UHF-based wireless modem technology and the aircraft flight mission support software onto the off-the-shelf UMPC and GPS system. The employed UHF radio equipment allows communicating tactic data with another aircrafts on the air, the ground control point, and even the Tactical Air Control Party(TACP) control vehicle that achieve missions with aircrafts. It thereby increases such capabilities as navigation aid, situation awareness, quick target identification and attack. We also applied Closed Air Support(CAS) scenarios, which is very close to the real environment, to the experiments of the proposed system. The experimental results show that the proposed system could support the data communication capability effectively and the flight mission at low costs of money and time.

• 한국대기환경학회지
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• 제21권2호
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• pp.169-178
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• 2005

A critical component of air pollution modeling is the representation of atmospheric flow fields within a model domain, since an accurate air quality simulation requires an accurate portrayal of the three-dimensional wind fields. The present study investigated data assimilation using surface observational data in the complex coastal regions to simulate a realistic atmospheric flow fields. Surface observational data were categorized into three groups (Near coastal region, Far coastal region 1, Far costal region 2) by the locations where the sites are. Experiments were designed according to the location of observational stations and MM5/CALPUFF was used. The results of numerical simulation of atmospheric flow fields are used as input data for CALPUFF which predicts dispersion fields of air pollutants. The result of this study indicated that data assimilation using data in the far coastal region 2 provided an attractive method for generating realistic meteorological fields and dispersion fields of air pollutants in Gwangyang area because data in the near coastal region are variable and narrow representation.

• 대한후두음성언어의학회지
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• 제9권2호
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• pp.109-114
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• 1998

Background and Objectives : Aerodynamic investigation is valuable information about the efficiency of the larynx in translating air pressure to acoustic signal. The normal data of the Korean has been reported, but there is no basic data of professional western classical singers who have learned how to control the flow of expiratory air for singing. The purpose of this study was to investigate the normal aerodynamic data of korean professional western classical singers and compare this with that of the Korean Materials and Methods : 50 Korean western classical singers were studied. Expiratory lung pressure combined with measurements of the mean air flow rate, voice frequency and intensity were measured with the aerodynamic test using airway interruption method. These data were compared with normal data of untrained normal adults. Results and Conclusions : The voice frequency and the voice intensity were increased in the western classic singers, but the mean air flow rate and the expiratory air pressure of the classical singers were within the same range of the untrained normal adults. This result means that western classical singers can change the loudness and pitch with a little increased or decreasing the mean air flow and the expiratory air pressure.

• 대한건축학회논문집:구조계
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• 제35권11호
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• pp.181-188
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• 2019

The purpose of this study is to evaluate the cooling energy saving effects of CRAH supply air temperature(SAT) and design flow rate changes when applying air-side economizer in the data center. MLC(Mechanical Load Component), which is cooling performance indicator of data center, was used to assess the effectiveness of cooling energy savings. It was computed with energy simulation (DesignBuilder) to evaluate the cooling energy performance of 8 different alternatives in a data center. The MLC was 0.31~0.32 regardless of CRAH supply temperature without air-side economizer, and 0.15 to 0.19 value with air-side economizer. That is, cooling energy can be reduced by approximately 40~55% when applying economizer. As the CRAH SAT and design flow rate changed, the MLC values were 0.16 to 0.18 and 0.15 to 0.19, respectively.

• 한국멀티미디어학회논문지
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• 제20권2호
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• pp.363-370
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• 2017

Data assimilation is an initializing method for air quality forecasting such as PM10. It is very important to enhance the forecasting accuracy. Optimal interpolation is one of the data assimilation techniques. It is very effective and widely used in air quality forecasting fields. The technique, however, requires too much memory space and long execution time. It makes the PM10 air quality forecasting difficult in real time. We propose a fast optimal interpolation data assimilation method for PM10 air quality forecasting using a new kernel tridiagonal sparse matrix and CUDA massively parallel processing architecture. Experimental results show the proposed method is 5~56 times faster than conventional ones.

• Journal of Korean Society for Atmospheric Environment
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• 제19권E2호
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• pp.75-81
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• 2003

Variational data assimilation, which is recently introduced to the air quality modeling, is a promising tool for obtaining optimal estimates of initial conditions and other important parameters such as emission and deposition rates. In this paper. two advanced techniques for variational data assimilation, based on the adjoint and quasi-inverse methods, are tested for a simple air quality problem. The four-dimensional variational assimilation (4D-Var) requires to run an adjoint model to provide the gradient information in an iterative minimization process, whereas the inverse 3D-Var (I3D-Var) seeks for optimal initial conditions directly by running a quasi -inverse model. For a process with small dissipation, I3D-Vu outperforms 4D-Var in both computing time and accuracy. Hybrid application which combines I3D-Var and standard 4D-Var is also suggested for efficient data assimilation in air quality problems.

• 환경위생공학
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• 제10권3호
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• pp.124-130
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• 1995

Air pollution problem by air craft was reviewed from emission gas components from air craft and pollutants amount generated in airport with the compareness of domestic transportation data by airplane and foreign data. It is reported that concentration of emission gas from air craft is lower than that of pollutants from automobile and factory. But transportation frequency is increasing rapidly in Korea. It is recommended that concerns should be taken on long- term of counterplan device about it.