• 한국농공학회논문집
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• 제64권5호
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• pp.27-39
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• 2022

The smart farm is recognized as a solution for future farmers having positive effects on the sustainability of the poultry industry. Intelligent microclimate control can be a key technology for broiler production which is extremely vulnerable to abnormal indoor air temperatures. Furthermore, better control of indoor microclimate can be achieved by accurate prediction of indoor air temperature. This study developed predictive models for internal air temperature in a mechanically-ventilated broiler house based on the data measured during three rearing periods, which were different in seasonal climate and ventilation operation. Three machine learning models and a mechanistic model based on thermal energy balance were used for the prediction. The results indicated that the all models gave good predictions for 1-minute future air temperature showing the coefficient of determination greater than 0.99 and the root-mean-square-error smaller than 0.306℃. However, for 1-hour future air temperature, only the mechanistic model showed good accuracy with the coefficient of determination of 0.934 and the root-mean-square-error of 0.841℃. Since the mechanistic model was based on the mathematical descriptions of the heat transfer processes that occurred in the broiler house, it showed better prediction performances compared to the black-box machine learning models. Therefore, it was proven to be useful for intelligent microclimate control which would be developed in future studies.

• KIEAE Journal
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• 제14권6호
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• pp.99-104
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• 2014

Recently supply of low energy house is increasing which can enhance energy efficiency and indoor environment comfort. Low energy house have to secure air tightness as well as thermal performance so house become high airtightness and inevitably need heat recovery ventilator to enhance indoor air quality. However, most of current ventilation systems are one-click, controlling the entire space so it causes increasing of heating load and fan power which makes it hard to save energy. Thus, Individual Control system is required which can achieve both enhancing indoor air quality and decreasing heating load and electric fan power. Thereby, in this study, we analyzed the correlation between ventilation and fan power through mock-up experiment and measured ventilation load under individual control system. As a result, under the condition of $24^{\circ}C$ of indoor temperature for 6 month(November to April) in Daejeon, ventilation load by fan speed was $10.9{\sim}19.6kWh/m^2{\cdot}a$ when operated 24 hours and $7.6{\sim}13.7kWh/m^2{\cdot}a$ when operated 12 hours in night time. In addition, it is possible to reduce at most 60% of ventilation load under the individual control system; measured ventilation load was $7.4kWh/m^2{\cdot}a$ when operated 24 hours, and $5.5kWh/m^2{\cdot}$ when operated 12 hours in night time.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제21권1호
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• pp.7-15
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• 2015

Purpose : When natural disaster occurs, the victims are evacuated to temporary shelters such as indoor gymnasiums or large space buildings until their homes are recovered. If someone in this temporary shelter is infected with an airborne infectious disease, it becomes easier for the disease to spread to the other people in the shelter than it would be under normal conditions. Therefore, temporary shelters need to provide not only water and food but also hygienic indoor conditions. Methods : In this study, the use of mechanical systems such as ultraviolet germicidal irradiation (UVGI) systems and air cleaners were simulated using numerical analysis to find out how these systems can control airborne infection in temporary shelters. An indoor gymnasium was selected as a temporary shelter for the numerical simulation model considering Korea's post-disaster response system. Influenza A virus was assumed as an airborne infectious disease and the diffusion of the virus was made by one person in the shelter. Results : The result of this study showed that the UVGI systems disinfected the virus more effectively than the air cleaners by creating a more stable airflow after the disinfection process. The air cleaners could remove the virus but since it created an unstable airflow in the temporary shelter, the virus was condensed to a certain area to show a higher virus concentration level than the source location. Implications : In the temporary shelter, it is necessary to use UVGI systems or air cleaners for hygienic indoor conditions.

• KIEAE Journal
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• 제7권4호
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• pp.39-44
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• 2007

The purpose of this research is to study security of $CO_2$ exhaust at night in indoor air quality purifying system using plants. For this purpose, two same units for experiment were built, and difference of $CO_2$ exhaust by existence and nonexistence of plantation were measured. To reduce error by entrance of people, automatic measurement system were developed and used. At first, baseline were measured to check standard value, and next, $CO_2$ exhaust by plantation were measured. As a result, in baseline experiment, values of all spaces were steady as 400~500 ppm. When plantation was set-up, value of $CO_2$ at night was measured high as 150 ppm, and maximum value was around 600 ppm. This result is a lot lower than maximum standard of $CO_2$, 1000 ppm.

• 한국실내디자인학회논문집
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• 제16권2호
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• pp.303-313
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• 2007

Nowadays, according to many studies, indoor space's pollution level is two to ten times higher than outdoor space's. This result arouses our attention. The major causes of deterioration of indoor air quality are the lack of ventilation caused by draught-proofing and insulation construction, and harmful chemical substances emitted from building materials, office machine and furniture. Therefore, we are continuing research to find the method for healthful house and production of many forms of well-being goods. However, because of exaggerated advertisements and the lack of accurate information, consumers choose the products whose performance is not verified. Therefore, this study investigates the actual conditions of pollution by building materials and the extent of the health damage by this pollution, and suggests the method for minimizing indoor pollution in aspect of indoor environment control and the use of environment friendly materials. But the building materials presented in this study are limited to the environment friendly construction materials that are in circulation In domestic market because this research is primarily aimed to give domestic consumers the standard for selecting this materials.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.449-452
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• 2005

For home networking system with a function of air quality monitoring, a wireless sensor module with several air quality monitoring sensors was developed for indoor environment monitoring system in home networking. The module has various enlargements for various kinds of sensors such as humidity sensor, temperature sensor, CO2 sensor, flying dust sensor, and etc. The developed wireless module is very convenient to be installed on the wall of a room or office, and the sensors in the module can be easily replaced due to well designed module structure and RF connection method. To reduce the system cost, only one RF transmission block was used for sensors' signal transmission to 8051 microcontroller board in time sharing method. In this home networking system, various indoor environmental parameters could be monitored in real time from RF wireless sensor module. Indoor vision was transferred to client PC or PDA from surveillance camera installed indoor or desired site. Web server using Oracle DB was used for saving the visions by web-camera and various data from wireless sensor module.

• 설비공학논문집
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• 제13권5호
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• pp.313-320
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• 2001

In the present study, various experiments were performed to investigate capacity modulation and refrigerant flow distribution of a multi-heat pump using a variable speed compressor and electronic expansion valves(EEVs) in the cooling mode. Based on the experimental results, it was possible to understand the interrelation of dual indoor units which provides some difficulties in capacity control of each indoor unit. The characteristics of capacity modulation of two indoor units were measured by controlling two EEVs with a cooling load of each indoor unit.

• 설비공학논문집
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• 제24권11호
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• pp.813-822
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• 2012

In this study, the multizone simulation for biosafety of BSL3 lab. and energy simulation are carried out simultaneously by using linked model of CONTAM and TRNSYS. In BSL3 lab., annual energy consumption is approximately five to ten times more than the magnitude of the office building. This is because required air change rate is extremely large and it is difficult to maintain room pressure difference efficiently. To maintain pressure difference between laboratory rooms through sealing condition of doors and proper airflow control is significant. In this study, to predict indoor environment of the BSL3 lab.(Influenza A research lab.), the multizone simulation for four kinds of biohazard scenario is also performed as part of risk assessment. Multizone and energy simulation results by using linked model show that these approaches are used as a tool for the energy efficient design and operation method for the safer BSL3 lab. facilities.

• 설비공학논문집
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• 제12권5호
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• pp.446-475
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• 2000

Performance of a water-to-water multi-type heat pump system using R22 has been experimentally investigated. Total refrigerant flow rate was adjusted with a variable speed compressor and the refrigerant flow rate for two indoor units were controlled by electronic expansion valves. Evaporator outlet pressure of refrigerant and indoor unit outlet temperatures of secondary fluid were selected as controlled variables. Experiments were carried out for both cooling and heating modes using PID control method. Results show that the multi-type heat pump system can be adequately controlled by keeping control gains at certain levels for various operating conditions.

• 한국지열·수열에너지학회논문집
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• 제12권4호
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• pp.40-46
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• 2016

In order to improve air quality of indoor environment, studies of the underfloor air distribution (UFAD) system for application in buildings are actively in progress based on temperature and air flow distribution. However, although the age of air is the major evaluation parameter, there has been very little study on this parameter for the UFAD system. In this study, we investigated the age of air to reach the air diffuser, which is installed at the bottom of the interior by the UFAD system. Computational fluid dynamics simulations showed no regular pattern to the maximum value of the age of air in accordance with air flow rate and the velocity at air diffuser. These factors can be deduced from air movement by considering that air emitted from air conditioners was rotated according to the bottom shape of the floor, and then, the age of air in the rotation center was increased. The average age of air of internal interior was reduced considerably as the flow velocity at the underfloor air diffuser was increased from 0.5 m/s to 1.0 m/s However, the age of air was not substantially affected with change in the air volume. Moreover, when the flow velocity at the underfloor air diffuser was higher than 1.0 m/s, the age of air showed no significant difference with change in air volume or height of measurement. These results imply that indoor air quality is more substantially influenced by flow velocity than air volume, and the appropriate flow velocity is 1 m/s or more.