• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제24권3호
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• pp.29-38
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• 2018

Purpose: Space planning to cope with the changing function of the hospital is essential in hospital architecture. In order to do so, it is vital that the paradigm shifts from hospital design focused on purpose toward hospital design focused on system. Not only space planning but also air-conditioning plan, which is most closely related to the operation and maintenance of hospital facilities; and the environment of hospital users, should be able to respond to changes with ease. Thus this study is to provide fundamental data of the air-conditioning plan for the hospital design focused on system by analyzing the concept and characteristics of the air-conditioning plan in the recent hospital architecture planning. Results: As a result of this study, in the air conditioning plan for the hospital architecture planning, the most important are the location relation among the departments the air handling unit room and the air handling unit manage and the air conditioning zoning setting according to the air conditioning system. Therefore, for the hospital architecture planning focused on system, it is necessary to establish the air conditioning setting that can accommodate changeable environment of departments and accordingly the appropriate area range of the air conditioning zoning and the plan for the location of the air handling unit should be considered. Implications: Thereby aims to provide fundamental data on air handling unit zoning planning in the hospital architecture planning.

• 설비공학논문집
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• 제13권10호
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• pp.966-973
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• 2001

In this study, measurement and analysis of energy consumption of an office building with cleanroom and laboratory have been conducted. Data acquisition system for collecting energy consumption data of the whole building including air-conditioning equipments has been installed in a building located in Seoul. Data are collected for a period of one year in 2000 and analyzed for studying the energy consumption pattern. The percentage of electrical energy used for air-conditioning system is measured to be 46.1%. The collected data will serve as valuable information for diagnosing and improving the energy system of the building.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.357-362
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• 2008

The present study has been conducted variable refrigerant flow system applied building. Multi air-conditioning system has some benefits : easier building management and maintenance and energy saving. Recently, the system heat pump has been employed in medium-sized and tall buildings. However, the performance data and design method for system heat pump are limited in literature due to complicated system parameters and operating conditions. In the present study, case study of a system heat pump applied various building. The aim of this paper is to application multi air-conditioners and to inform the benefits of multi air-conditioners.

• 설비공학논문집
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• 제28권5호
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• pp.178-185
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• 2016

This study describes the analysis of a 20 MW chilled water plant used for the IT cooling of a recently constructed data center in Korea. The CFD model was developed with the aim of evaluating the impact of problems such as chiller failure on the water and air temperatures in the cooling system. The numerical model includes the chilled water hydraulic network and individual water-to-air CRAC units. The coupling between the IT server room air temperature levels and the cooling plant has enabled a full assessment of the cooling system design in response to system fault conditions to be performed. The paper examines an emergency situation involving the failure of the cooling plant, and shows how the inherent thermal inertia of the system along with additional inertia achieved through buffer systems allowed a suitable design to be achieved.

• 한국항행학회논문지
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• 제18권4호
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• pp.278-287
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• 2014

ADS-B는 지속적으로 증가하는 항공 수요에 대응하기 위해 새롭게 개발된 항공 감시 기술로 레이더에 비해 높은 정확도와 빠른 갱신 주기를 제공하여 레이더를 대체하거나 보완할 수 있을 것으로 주목받고 있다. 하지만 지상 시스템과 항공기 간의 정보 교환에 무선 데이터링크를 사용하며 지상 시스템 내부의 정보 교환에 무결성이 보장되지 않는 프로토콜을 사용하기 때문에 ADS-B 시스템의 운용 상태를 감시할 수 있는 시스템이 반드시 필요하다. 본 논문에서는 ADS-B 시스템의 운용 상태 감시 기능과 더불어 ADS-B 감시 자료, 레이더 감시 자료, 비행 정보를 활용하여 항공 교통 상황을 종합적으로 현시할 수 있는 항공 교통 상황 종합 현시 기능을 갖는 ADS-B 모니터링 시스템을 설계하고 구현하였다. 구현한 시스템은 직접 구성한 ADS-B 지상 시스템과 연결하여 비행중인 항공기의 ADS-B 감시 자료와 레이더 감시 자료, 가상의 비행 정보를 수신한 뒤 현시하는 방법을 통하여 검증하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.439-441
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• 2007

The seoul metropolitan subway has installed 8 lines and about 500 stations to transport 5 million passengers everyday. The underground air pollution level in the subway stations is very severe status, which is very harmful to the commutators and its personals. Although subway roles as such a massive and huge transportation system, the subway doesn't adapt yet any real-time air monitoring system. They have only some hand-held type detector equipments for monitoring air pollution. Therefore subway passengers are exposed to the harmful air pollution environment. The most harmful environmental parameters among the air pollution are known as the dust and sound noise dB level in the subway station. Because the dust is consisted of very small particles, we can't see them easily in dark condition on the platform, but it is very harmful. The monitoring system for air pollution is developed using embedded system attached with 6 different environmental sensors. This system monitors air pollution of dust sound noise, gas, temperature, humidity, inflammable gas, toxic gas in the subway ?station. The sensor unit of the ARM-CPU board and sensor transmits real time environmental data to the main server using Zigbee wireless communication module and TCP/IP network. The main control server receives and displays the real-time environmental data, and it send alarms to the personals when high level value.

• 설비공학논문집
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• 제13권11호
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• pp.1089-1096
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• 2001

The cool-down performance after soaking is very important in an automotive air-conditioning system and is considered as the key design variable. Therefore, understanding of the overall transient characteristics of the system is essential to the preliminary design as well as steady-state characteristics. The objective of this study is to develop a computer simulation model and estimate theoretical1y the transient performance of an automotive air-conditioning system. To accomplish this, a mathematical modelling of each component, such as compressor, condenser, expansion valve, and evaporator, is presented first of all. For a detailed calculation, condenser and evaporator are divided into many subsections. Each sub-section is an elemental volume for modelling. In models of expansion valve and compressor, dynamic behaviors are not considered in an attempt to simplify the ana1ysis, but the quasi-static ones are just considered, such as the relation between mass flow rate and pressure drop in expansion device, polytropic process in compressor, etc. The developed simulation model is validated with a comparison to laboratory test data of an automotive air-conditioning system. The overall time-tracing properties of each component agreed fairly well wish those of test data in this case.

• 동력기계공학회지
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• 제4권3호
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• pp.34-39
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• 2000

Performance data in the literature on air lift pumps have been based primarily on pumps of long length and large diameter (high lift pumps). Since mariculture operations involve pumps of relatively short length and small diameter, performance data are required for efficient operation. To provide such data, an experimental apparatus was designed and fabricated to test all lift pumps from 2.1 to 3.4 cm inside diameter and from 40 to 300 cm in length. Instrumentation was provided to measure water flow rate and air flow rate as well as water temperature, air temperature, and pressure throughout the system. Results from this study correlate well with high lift pump data in that, for a given pump geometry, maximum water flow occurs for a specific air flow rate. Driving the pump with air flows larger or smaller than this optimum flow rate will decrease the pumping rate. The optimum flows are significantly different for low lift pumps compared to high lift pumps. However, the pumping rate for low lift pumps approaches that for high lift pumps with increasing length.

• 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.

• Transactions on Control, Automation and Systems Engineering
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• 제1권1호
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• pp.75-86
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• 1999

An air-data estimator for generic air-breathing hypersonic vehicles (AHSVs) is developed and demonstrated with an example vehicle configuration. The AHSV air-data estimation strategy emphasized improvement of the angle of attack estimate accuracy to a degree necessitated by the stringent operational requirements of the air-breathing propulsion. the resulting estimation problem involves highly nonlinear diffusion process (propagation); consequently, significant distortion of a posteriori conditional density is suspected. A simulation based statistical analysis tool is developed to characterize the nonlinear diffusion process. The statistical analysis results indicate that the diffusion process preserves the symmetry and unimodality of initial probability density shape state variables, and provide the basis for applicability of an Extended Kalman Filter (EKF). An EKF is designed for the AHSV air-data system and the air data estimation capabilities are demonstrated.