• Proceedings of the SAREK Conference
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• 2007.11a
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• pp.46-51
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• 2007

The near-optimal control algorithm for central cooling system has been developed for minimizing energy consumption while maintaining the comfort of indoor thermal environment in terms of the environmental variables such as time varying indoor cooling load and outdoor temperatures. The optimal set-points of control parameters with near-optimal control are supply air temperature and chilled water temperature. This study has been done by using LapVIEW program with PID control in order to analyze the central cooling system energy saving.

• Journal of Bio-Environment Control
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• v.9 no.1
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• pp.27-39
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• 2000

In this study, we quantitatively compare the cooling effects of single span plastic greenhouses by opening or shutting of toot and side vents, and operation of fan or sprinkler. With those variables, we simultaneously made experiments at 4 greenhouses under equivalent conditions. By the experiments, the shutting of roof and side vents caused the high temperature difference of indoor and outdoor which the crops cannot be cultivated. However, the opening of the windows effectively reduced the indoor temperature and showed uniform temperature distribution in the greenhouses. The sprinkler abruptly reduced the indoor temperature, and showed excellent cooling effects. Finally, this paper provides the fundamental data for environmental control in greenhouses.

• Journal of IKEEE
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• v.19 no.4
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• pp.603-609
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• 2015

Thermal comfort is one of the fundamental aspects of indoor environmental quality and it is strongly related to occupant satisfaction and energy used in building. In this paper, we proposes smart comfort algorithm that save energy and provide a pleasant and comfortable environment for workers by the indoor comfort conditions(Predictive Mean Vote) detection and controlling the temperature and humidity, air flow. Simulation results, heating and cooling control of the thermal comfort control can be compared with the existing general air conditioners reduces the power of 0.5kW and indoor comfort can be maintained. Also, It showed a 49.2% improvement in the light by lighting control algorithm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.5
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• pp.2536-2543
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• 2013

In this paper, we proposed the modeling in one zone buildings and the energy efficient temperature control algorithm using particle swarm optimization (PSO). A control horizon switching method with PSO is used for optimal control, and the TOU tariff is included to calculate the energy costs. Simulation results show that the reductions of energy cost and peak power can be obtained using proposed algorithms.

• Animal Bioscience
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• v.35 no.12
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• pp.1977-1985
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• 2022

Objective: This study was conducted to determine the seasonal characteristics of odorous material emissions from a swine finishing barn equipped with a continuous pit recirculation system (CPRS) using aerobically treated manure. Methods: The CPRS consists of an aerobic manure treatment process and a pit recirculation system, where the solid fraction is separated and composted. The aerated liquid fraction (290.0%±21.0% per day of total stored pig slurry) is continuously recirculated to the top of the slurry in the pit. Four confinement pig barns in three piggery farms were used: two were equipped with CPRS, and the other two operated a slurry pit under the slatted floor across all seasons. Results: The indoor, exhaust, and outside odor intensities were significantly lower in the CPRS group than in the control group (p<0.001). In the CPRS group, the odor intensity outside was significantly lower in the fall than in the other seasons (p = 0.015). In the indoor atmosphere, the temperature and CO₂, NH₃, and H₂S contents of the CPRS group were significantly lower than those of the control group (p<0.05). In the CPRS group, indoor temperature did not significantly change in the spring, summer, and fall seasons and was significantly lower in the winter (p = 0.002). NH₃, H₂S, methyl mercaptan, dimethyl disulfide, trimethylamine, phenol, indole, and skatole levels were significantly lower in the CPRS group than in the control group (p<0.05). There were significant seasonal differences on the odorous material in both the control and CPRS groups (p<0.05), but the pattern was not clear across seasons. Conclusion: The CPRS can reduce the indoor temperature in the summer to a level similar to that in the spring and fall seasons. The CPRS with aerated liquid manure is expected to reduce and maintain malodorous emissions within acceptable limits in swine facilities.

• Solar Energy
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• v.19 no.1
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• pp.59-65
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• 1999

The zone of greenhouse in Korea increase on a scale yearly. Particularly, greenhouse take up a important value on the agriculture economy. Greenhouse of scale, material, heating system, and drain is progressing to industrialization. The dry bulb temperature, humidity, photosynthesis and so forth are necessary to maintain environment control of greenhouse. The dry bulb temperature among them greatly affects growing of a plant. The purpose of this study is to analyzed the indoor environment control system and the characteristic of dry bulb temperature distribution on a large scale greenhouse in summer season.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.8
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• pp.780-786
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• 2001

For the compressor speed control of a multi-type air conditioning system, a fuzzy control algorithm was developed. The sum of zone temperature errors and its derivative were used as input variables, and the compressor speed was selected as the output variable. To test the effectiveness of the control algorithm, one outdoor environmental chamber and four indoor environmental chambers were used. In the chambers the zone temperature step change test and the indoor unit change over test were performed. Test results showed that, for the control of compressor speed, the fuzzy control algorithm was more effective than the conventional proportional control algorithm for the energy conservation.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.14 no.4
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• pp.13-19
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• 2018

The Effects of hot water supply temperature on indoor thermal characteristics for floor radiant heating system in residential apartment were researched by computer simulation. The parametric study on hot water supply temperatures with different outdoor air temperatures was done with regard to energy performance and control characteristics, respectively. As a result, the maximum overshoot of indoor air temperature and energy consumption were reduced by adjusting the hot water supply temperatures with outdoor air temperatures.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.14-20
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• 2015

It is important to understand psychological and physiological responses of occupants who seated in a chair in order to shape a comfortable indoor official environment. So it is needed to find out optimal seated conditions. The purpose of this study was to explore optimal condition of seat air conditioning control based on psychological or subjective responses (perceived temperature and comfort sensation) and physiological responses (heartrate variability; HRV). To do this, experimental conditions were designed by the difference of indoor temperature and seat air conditioning temperature. In the experiment 1, seven experimental conditions were designed with one control condition which was not used seat air conditioning system, and six experimental conditions which the difference of indoor temperature and seat air conditioning temperature ($-1^{\circ}C{\sim}-6^{\circ}C$). In the experiment 2, four experimental conditions were designed with one control condition and three experimental conditions ($-3^{\circ}C{\sim}-5^{\circ}C$). In addition, participants' psychological or subjective response was measured by CSV (comfort sensation vote) and PTS (perceived temperature sensitivity) as a psychological or subjective response, and heartrate variability was measured as a physiological response. As a result, in the experiment 1, it was reported that the optimal conditions of seat air conditioning control based on participants' psychological or subjective comfort were from $-3^{\circ}C$ to $-5^{\circ}C$ experimental conditions. In addition, in the experiment 2, it was reported that the optimal condition of seat air conditioning control based on participants' physiological comfort was $-4^{\circ}C$ experimental condition. These results suggested that seat air conditioning could affected to comfort sensation of occupants in an appropriate range, rather than unconditionally.

• Journal of Bio-Environment Control
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• v.9 no.2
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• pp.120-126
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• 2000

The quality of oak mushoom(Lentinus edodes(Berk) Sing) is sensitively affected by environmental factors, especially moisture by the rain during the growing period. To protect mushrooms from being wet, plastic-covered facilities with side openings are mostly being used. However, the indoor temperature and humidity f the facility without roof opening become higher due to its poor ventilation, and consequently reduce the productivity and quality as well. In this study, we analyzed the ventilation rates and indoor temperatures of improved facilities as affected by the area of roof opening and shading rate by the model. The indoor temperature decreased by more than 2.5$^{\circ}C$ as the shading rate increased from 50% to 90%, and especially the effect of wind speed on indoor temperature was significantly great under as low as 50% of shading rate. The ventilation rate became higher under wind speed of 1~2m.s-1 regardless of the shading rate. As the wind speed increased from 0m.s-1 to 2m.s-1, the indoor temperature decreased by more than 2.$0^{\circ}C$. Moreover, the indoor temperature became lower with increasing roof opening ratio, but showed no significant differences at more than 50% of roof opening ratio. At lower shading rate, the indoor temperature sensitively decreased with increasing area of roof opening. Additionally, we obtained the higher ventilation performance with the area of roof opening more or less equal to side opening, regardless of the wind speed and shading rate.