• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 춘계학술대회
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• pp.347-350
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• 2018

사용자가 집에 도착하기 전에 IoT 시스템이 집안 온도를 자동으로 쾌적하게 하기 위해서는 사용자의 도착 예정 시간에 맞게 설정한 온도에 도달할 수 있는 최적의 에어컨 및 난방의 가동 시작 시간을 예측해야 한다. 가동 시간을 정확하게 예측한다면 불필요한 가동시간을 줄일 수 있기 때문에 요금 낭비를 피할 수 있는 효과가 있다. 본 논문은 에어컨과 보일러를 사용하는 집의 냉난방 시간을 예측하는 인공신경망과 이를 활용하는 IoT 시스템을 소개한다. 에어컨과 보일러가 특정 시작 온도에서 특정 목표 온도로 집안을 냉난방 하는데 걸리는 시간에 영향을 주는 변수는 집안의 구조, 집안의 크기, 외부 날씨 환경 등으로 매우 다양하다. 그중에서 측정 가능한 변수인 집안 온도, 집안 습도, 외부 온도, 외부 습도, 풍향, 풍도, 풍속 냉각 효과를 활용하여 학습데이터를 만들고 최적의 인공신경망을 구축하였다. 인공신경망을 구축한 후에는 이를 활용하는 IoT 시스템을 개발하였다. IoT 시스템은 라즈베리파이3 기반의 메인 시스템과 안드로이드 기반의 모바일 애플리케이션으로 구성하였다. 인공신경망을 활용하기 위해 모바일 애플리케이션의 GPS 센서를 활용하여 사용자의 이동 분석하고 귀가 시간을 예측하는 기능을 구현하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1327-1334
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• 2011

subway has became citizen's feet which can transport over 24 million people since the era of high oil price started. Because the request of passengers for more comfortable thermal comfort is drastically increasing, the importance of comfortable environment in the passenger car is more stressed. This paper suggests an indicator whether railroad car is fitted with suitable cooling and heating equipment by applying the international climatic testing method, UIC 553, 553-1. Specified ambient temperature, humidity, solar irradiation condition, as well as extreme outside condition, can be achieved by using an environmental chamber. The change temperature and humidity in the passenger space can be monitored to judge if the passenger room is nicely air-conditioned.

• 대한기계학회논문집B
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• 제21권1호
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• pp.15-23
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• 1997

An experimental investigation of two-dimensional steady natural convection cooling in a vertical open top cavity with conducting side walls of finite thickness is presented. The various heat-generating discrete heaters are located on one vertical wall of the cavity. When each heater dissipates different amount of power, the purpose of the work is to obtain the optimal array condition of the heaters. The four cases of non-uniform heating conditions are considered. The temperature fields in the cavity were visualized by the interferometer and local temperatures of the vertical wall were measured by thermocouples. The heaters were arranged in two configurations: flush-mounted on a vertical wall or protruding from the wall about 4.5 mm. The vertical wall was constructed out of copper or epoxy-resin sheet. Experiments have been conducted for air with constant Prandtl number(Pr=0.7), the aspect ratio of 4.6, 7.5, 9.5, power input in the range of 0.9 W ~ 4.2 W. For the enhancement of the cooling effectiveness, the upper and lower of vertical wall would give the better position for the heaters of higher heat flux.

• 생물환경조절학회지
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• 제25권2호
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• pp.123-132
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• 2016

The importance of energy saving technology for managing greenhouse was recently highlighted. For practical use of energy in greenhouse, it is necessary to simulate energy flow precisely and estimate heating/cooling loads of greenhouse. So the main purpose of this study was to develope and to validate greenhouse energy model and to estimate annual/maximum energy loads using Building Energy Simulation (BES). Field experiments were carried out in a multi-span plastic-film greenhouse in Jeju Island ($33.2^{\circ}N$, $126.3^{\circ}E$) for 2 months. To develop energy model of the greenhouse, a set of sensors was used to measure the greenhouse microclimate such as air temperature, humidity, leaf temperature, solar radiation, carbon dioxide concentration and so on. Moreover, characteristic length of plant leaf, leaf area index and diffuse non-interceptance were utilized to calculate sensible and latent heat exchange of plant. The internal temperature of greenhouse was compared to validate the greenhouse energy model. Developed model provided a good estimation for the internal temperature throughout the experiments period (coefficients of determination > 0.85, index of agreement > 0.92). After the model validation, we used last 10 years weather data to calculate energy loads of greenhouse according to growth stage of greenhouse crop. The tendency of heating/cooling loads change was depends on external weather condition and optimal temperature for growing crops at each stage. In addition, maximum heating/cooling loads of reference greenhouse were estimated to 644,014 and $756,456kJ{\cdot}hr^{-1}$, respectively.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2007년도 동계학술발표대회 논문집
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• pp.3-8
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• 2007

The purpose of this study is to grasp the characteristic of indoor thermal environment from large enclosures in connection with heating and cooling condition. This study has measured indoor thermal environment in winter and summer season. We examined indoor thermal environment of the large enclosures in this study which include vertical, horizontal temperature distribution and thermal comfort environment.

• 치위생과학회지
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• 제11권4호
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• pp.353-359
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• 2011

본 연구는 치과위생사가 근무하는 병원의 미세먼지(PM-10), 포름알데히드(HCHO), 이산화탄소($CO_2$), 일산화탄소(CO), 휘발성유기화합물(VOCs) 등에 의해 오염된 실내공기가 치과위생사의 건강 및 작업능률에도 많은 영향을 끼친다는 사실을 인식하여 치과위생사를 대상으로 근무하는 병원의 냉 반방 방식 및 창문개폐를 통한 환기 횟수에 따른 실내공기질에 대한 신체자각증상 정도를 비교하고, 근무하는 병원의 실내공기질과 관련된 환경 만족에 미치는 요인을 분석하므로써 치과위생사의 건강관리를 위한 효율적인 근무환경개선방안을 제시하기 위하여 시도되었다. 조사대상자는 전국 치과병 의원에 근무하는 치과위생사로 하였으며 2010년 10월 1일 부터 2011년 1월 21일까지 자기기입식 설문조사 방식으로 582부의 설문지를 수집하여 SPSS 12.0 프로그램을 이용하여 분석하였다. 1. 냉 난방 방식별 창문 개폐를 통한 하루 환기 횟수를 비교한 결과 창문개폐를 통한 환기가 편리한 개별 냉 난방 방식에서 높은 것으로 나타났다. 2. 치과위생사는 실내공기질과 관련된 자각증상으로 인하여 불편함을 가장 많이 느끼는 시간은 오후 2시 전 후이며 불편함을 느끼기 시작한 지 1시간 경과 후인 3시 전 후에 불편함의 정도가 가장 심한 것으로 조사되었다. 3. 치과위생사의 자각증상에 따른 불편함 수준을 냉 난방 방식 및 하루 창문개폐를 통한 환기 횟수와 비교하여 분석한 결과 창문 개폐를 이용하여 자연환기가 유리한 개별 냉 난방 방식의 사무실에 근무하는 치과위생사의 수준이 낮은 것으로 나타났다. 4. 근무하는 병원의 만족에 미치는 요인을 실내공기 조건과 관련된 항목을 독립변수로 하여 중회귀 분석을 실시한 결과 "병원 공기의 냄새가 기분 좋게한다", "병원 실내 온도조건은 근무하기에 편하다", "병원의 조명은 일하기에 적당한 편이다", "병원의 환기가 잘 된다", "병원 시끄러움", "병원공기가 신선하다고 느낀다", "병원 더움" 순으로 유의하게 나타났으며 설명력은 42.9%인 것으로 나타났다.

• 한국태양에너지학회 논문집
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• 제31권5호
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• pp.33-40
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• 2011

In this study, it is quantitatively analyzed for thermal Characteristics of isolation-heat paint which has been supplied to a domestic market through experiments and simulations. In the case of experiment using the container box, it shows 8% decrease on cooling energy consumption in a summer season, but shows increase on heating energy consumption. As a result, the analysis has found increase of energy consumption. As a result of holding simulations with meteorological data of domestic major cities, it shows an increase of energy consumption in domestic condition, and it is hard to expect an energy saving from the isolation-heat paint unless greater air-conditioning load.

• 한국세라믹학회지
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• 제42권6호
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• pp.437-442
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• 2005

We fabricated BSCCO-2212 (2212) bulk superconductor by melt casting process, and evaluated the dependence of the critical properties on the temperature and cooling .ate of mold and the pouring methods of melt. It was observed that the critical current (Ic) of 2212 was significantly dependent on the pre-heating temperature of the mold. At the pre-heating temperature of $500^{\circ}C$ followed by air cooling condition, Ic of 48 A at 77 K was obtained which was higher than others processed at different temperatures. In addition, the Ic improved to 132 A when tilt casting method was applied. The improved Ic is probably due to the fact that the tilt casting reduced a turbulent flow of the melt during casting causing less porosity and more homogeneous microsructure. Critical temperature was measured to be 87-89 K after the first heat treatment and it improved to 90-91 K when subsequently heat treated at $650^{\circ}C$ in a nitrogen atmosphere. This improvement was considered to be due to an optimization of the oxygen content in the range of 8.16-8.2.

• 한국자동차공학회논문집
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• 제18권5호
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• pp.115-123
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• 2010

Cool-down performance after soaking is important because it affects passenger's thermal comfort. The cooling capacity of HVAC system determines initial cool down performance in most cases, the performance is also affected by location, and shape of panel vent, indoor seat arrangement. Therefore, optimal indoor designs are required in developing a new car. In this paper, initial cool down performance is predicted by CFD(computational fluid dynamics) analysis. Experimental time-averaging temperature data are used as inlet boundary condition. For more reliable analysis, real vehicle model and human FE model are used in grid generation procedure. Thermal and aerodynamic characteristics on re-circulation cool vent mode are investigated using CFX 12.0. Thermal comfort represented by PMV(predicted mean vote) is evaluated using acquired numerical data. Temperature and velocity fields show that flow in passenger's compartment after soaking is considerably unstable at the view point of thermodynamics. Volume-averaged temperature is decreased exponentially during overall cool down process. However, temperature monitored at different 16 spots in CFX-Solver shows local variation in head, chest, knee, foot. The cooling speed at the head and chest nearby panel vent are relatively faster than at the knee and foot. Horizontal temperature contour shows asymmetric distribution because of the location of exhaust vent. By evaluating the passenger's thermal comfort, slowest cooling region is found at the driver's seat.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.903-908
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• 2006

Building energy simulation has become a useful tool for predicting cooling, heating and air-conditioning loads for facilities. It is important to provide building energy performances feed back to the mechanical and electrical system operator and engineer for energy conservation and maintenance of building. From this research, we set up the typical weather data of location, basic description of building, geometric modelling data and the specification of Installed primary HVAC system for establishing the simulation model about energy consuming that take place in multipurpose building complex. The simulation tool of building energy - EnergyPlus (DOE and BLAST based simulation S/W), it has been used and accomplished calculations and analyses for evaluating the effect of the system types and operating condition of central HVAC plant on the building energy consumption. In this paper, we offer comparison and simultaneous results those involve electricity consumption pattern and amount between actual operation versus EnergyPlus simulation to the object building during summer season.