• 설비공학논문집
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• 제8권1호
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• pp.37-44
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• 1996

Water hammer pressure waves were measured in a simplified water piping system with and without arresters and air chambers by the operations of the solenoid valve. Experiments were performed to investigate the effects of the location of the arresters and the effects of the volume of the air chambers on maximum and minimum water hammer pressures and wave frequency for various flow rates.

• 설비공학논문집
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• 제13권4호
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• pp.252-261
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• 2001

Room air flow and temperature distribution was numerically investigated where a PAC(personal air conditioning) system was installed. The calculated results were compared with those from experiments. The effects of the important operation parameters such as the air flow rate, velocity, and temperature at the diffuser on the thermal performance of the system were studied. The possibility of energy saving using the PAC system was verified from the results, It was shown that the warm air from the diffuser could not spread over the whole task area if the inlet temperature was too high.

• Asian-Australasian Journal of Animal Sciences
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• 제14권12호
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• pp.1763-1768
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• 2001

The combined effects of low voltage electrical stimulation (ES) and early short-term temperature conditioning on meat quality of Hanwoo beef (Korean native cattle) during storage were investigated. Shear force was influenced by ES and aging. Combination of ES and the $30^{\circ}C$ conditioning resulted in higher myofibril fragmentation index and improved lightness. There was no substantial difference in drip loss among treatments but ES samples showed higher cooking loss than control. Negative effect on shelf-life was not found by early short-term high temperature conditioning. Therefore, the meat quality of Korean native cattle was effectively improved by the combination of ES and the $30^{\circ}C$ conditioning.

• Journal of Preventive Medicine and Public Health
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• 제53권1호
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• pp.15-25
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• 2020

Objectives: The purpose of this study was to investigate the health effects of air conditioning use during the 2018 heat wave in Korea, included the highest temperature ever recorded in the nation. Methods: The participants in this study were 1000 adults aged 19 years and older recruited from across Korea. The participants were asked about their experience of symptoms of various diseases, disruptions of their daily lives, and use of air conditioning during the heat wave. The associations between air conditioning use during the heat wave and health outcomes were analyzed using the chisquare test and multiple logistic regression models. Results: Among participants who lacked air conditioning in the main space where they spent time outside the home, 33.9%, 8.1%, 43.5%, and 19.4% experienced symptoms of heat-related, cardiovascular, nervous system diseases, and air-conditioningitis, respectively. In comparison, participants who did have air conditioning outside the home experienced the same symptoms at proportions of 21.0%, 1.9%, 26.8%, and 34.2%, respectively (p=0.027, 0.007, 0.007, and 0.023, respectively). Among participants who had no air conditioner at home, 10.0% were absent from school or work due to the heat wave. In contrast, among participants who had an air conditioner at home, only 3.7% were absent as a result of the heat wave (p=0.007). Conclusions: When air conditioning was not used at home or in the main space where participants spent time outside the home during the 2018 heat wave, adverse health effects were more prevalent, but the risk of air-conditioningitis was reduced.

• 설비공학논문집
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• 제15권10호
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• pp.852-859
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• 2003

R407C is considered as an alternative refrigerant of R22 for air conditioners. An experiment was carried out to investigate the characteristics of the evaporation heat transfer and pressure drop for refrigerant R407C flowing in a fin-and-tube heat exchanger used for commercial air-conditioning unit. The experimental data were useful in analyze the effects of the temperature glide and superheat for R407C. Test were conducted at the conditions of inlet refrigerant evaporation temperature of 7$^{\circ}C$, inlet air relative humidity of 50%, and refrigerant mass fluxes varying from 150 to 250 kg/m$^2$s. Representative results show that the heat exchanger performance for R407C evaporation is significantly affected by the change of the flow pattern from two-phase to super-heated vapor flow.

• Asian Journal of Business Environment
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• 제12권2호
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• pp.29-41
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• 2022

Purpose: In the era of sustainable development, the role of consumers and businesses has become increasingly important by demonstrating the importance of social and environmental issues. Accordingly, firms widely adopt cause-related marketing to fulfil corporate social responsibility. The purpose of this study is to examine factors that affect consumer attitude toward cause-related marketing with perspectives of the sustainable development goals (SDGs) and instrumental conditioning. Research design, data and methodology: Proposed research questions include effects of cognition, emotion, sustainability, and business ethics on attitude, effects of attitude on purchase intention, and effects of intention on satisfaction. This study collected the data via an online survey and applied factor and regression analysis. Results: Findings indicated that factors affect attitudes differently in cases of cause-related marketing with SDGs and instrumental conditioning. The results of this study found that business ethics affects consumer attitude and differ based on types of cause-related marketing. This study found that attitude positively affects purchase intention that also affects expected satisfaction. Conclusions: By applying perspectives of SDGs, findings of this study provide implications to producers, marketers, and policymakers to promote and achieve sustainability. In particular, the results found that business ethics should be more addressed to fulfill customer attitude.

• 수산해양기술연구
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• 제60권2호
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• pp.194-206
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• 2024

This study focuses on analyzing the energy-saving effects of the recirculation aquaculture system using seawater source heat pumps and solar power generation. Based on the thermal load analysis conducted using the transient system simulation tool, the annual energy consumption of the recirculation aquaculture system was analyzed and the energy-saving effects of utilizing the photovoltaic system was evaluated. When analyzing the heat load, the sea areas where the fish farms are located, the type of breeding tank, and the circulation rate of breeding water were taken into consideration. In addition, a method for determining the appropriate capacity for each operation time was examined when applying the energy storage system instead of the existing diesel generator as an emergency power, which is required to maintain the water temperature of breeding water during power outage. The results suggest that, among the four seas considered, Jeju should be estimated to achieve the highest energy-saving performance using the solar power generation, with approximately 45% energy savings.

• 아시안잔디학회지
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• 제7권1호
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• pp.13-18
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• 1993

Much attention has been given recently to solve the environmental contamination in golf courses Changing to culture practice rather than chemical practice that depends on pesticides and fertilizers is a hot issue in golf courses or grasslands. Organic soil conditioners improve soil-plant envirormental conditions rich in physical properties. In this study, measuring systems to evaluate soil conditioning effects were set up for on-site purpose. After establishing the methodology for evaluating soil conditioner effects, 2 kinds of organic conditioners were rested for examination. The systems for the methodology included a set of simulating equipment for field capacity, an impact type soil column compactor, and an infiltration-percolation system. Test results using the systems showed bulk density and infiltration rate of mixed soil were decreased at highter rates of conditioner, but total porocities were increased. Increased porocities were most capillary pore space which has a positive effect on soil water potential. The systems and methodology in this study seem to have an efficiency to measure the effects of soil conditioner on site purpose.

• Journal of Ginseng Research
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• 제13권2호
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• pp.189-197
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• 1989

A new quaternary ammonium compound, hydrolyzed ginseng-saponin quaternary (HGSQ), from Korean ginseng saponin and 2,3-epoxypropyltrimethylammonium chloride has been developed as a conditioning agent in cosmetics. This structure has a hydrophobic group from the aglycone of ginseng saponin which is biologically active and considered to be the most important component of the Korean ginseng. Its properties : surface tension, critical micelle concentration (CMC), eye irritation, sorption onto hair, force reduction(%) and moisture retention effect were studied. Its cationic character allows the molecule to be more substantive than ginseng saponin. HGSQ had good physical properties and was safe. enough as a cosmetic raw material. Also half-head tests of HGSQ-containing shampoo were carried out to compare the conditioning effects in shampoos. HGSQ was an excellent conditioning agent in shampoo..

• 설비공학논문집
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• 제15권6호
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• pp.543-550
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• 2003

In order to saving the energy for HVAC system of buildings, utilization of wind-induced cross ventilation is thought to be promising. However, utilization of natural ventilation alone is not sufficient for maintaining the human thermal-comfort such as in hot and humid regions. A hybrid air conditioning system with a controlled natural ventilation system, or combination of natural ventilation with mechanical air conditioning is thought to overcome the deficiency of wind-driven cross ventilation and to have significant effects on energy reduction. This paper describes a concept of hybrid system and propose a new type of hybrid system using radiational cooling with wind-induced cross ventilation. Moreover, a radiational cooling system is compared with an all-air cooling system. The characteristics of the indoor environment will be examined through CFD (Computational Fluid Dynamics) simulation, which is coupled with a radiation heat transfer simulation and with HVAC control in which the PMV value for the human model in the center of the room is controlled to attain the target value.