• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.14 no.12
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• pp.1102-1139
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• 2002

A review on the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering in 2000 and 2001 has been done. Focus has been put on current status of research in the aspect of heating, cooling, ventilation, sanitation and building environment. The conclusions are as follows. (1) Most of fundamental studies on fluid flow were related with heat transportation of facilities. Drop formation and rivulet flow on solid surfaces were interesting topics related with condensation augmentation. Research on micro environment considering flow, heat, humidity was also interesting for comfortable living environment. It can be extended considering biological aspects. Development of fans and blowers of high performance and low noise were continuing topics. Well developed CFD technologies were widely applied for developing facilities and their systems. (2) Most of papers related with heat transfer analysis and heat exchanger shows dealt with convection, evaporation, and channel flow for the design application of heat exchanger. The numerical heat transfer simulation studies have been peformed and reported to show heat transfer characteristics. Experimental as well as numerical studies on heat exchanger were reported, while not many papers are available for the system analysis including heat exchanger. (3) A review of the recent studies on heat pump system shows that performance analysis and control of heat pump have been peformed by various simulations and experiments. The research papers on multi-type heat pump system increased significantly. The studies on heat pipe have been examined experimently for change of working characteristics and strut lure. Research on the phase change has been carried out steadily and operation strategies of encapsulated ice storage tank are reported experimentally in several papers. (4) A review of recent studies on refrigeration/air conditioning system have focused on the system performance and efficiency for new alternative refrigerants. Evaporation and condensation heat transfer characteristics are investigated for tube shapes and new alternative refrigerants. Studies on components of refrigeration/air conditioning system are carried to examine efficiency for various compressors and performance of new expansion devices. In addition to thermophysical properties of refrigerant mixtures, studies on new refrigerants are also carried out, however research works on two-phase flow seemed to be insufficient. (5) A review of the recent studies on absorption cooling system indicates that heat and mass transfer phenomena have been investigated to improve absorber performance. Various experimental data have been presented and several simulation models have been proposed. A review of the recent studies on duct and ventilation shows that ventilation indices have been proposed to quantify the ventilation performance in buildings and tunnels. Main efforts have been focused on the applications of ventilation effectiveness in practice, either numerically using computational fluid dynamics or experimentally using tracer gas techniques. (6) Based on a review of recent studies on indoor thermal environment and building service systems, research issues have mainly focused on many innovative ideas such as underfloor air-conditioning system, personal environmental modules, radiant floor cooling and etc. Also, the new approaches for minimizing energy consumption as well as improving indoor environmental conditions through predictive control of HVAC systems, various activities of building energy management and cost-benefit analysis for economic evaluation were highlighted.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.2 no.3
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• pp.243-255
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• 1990

The objective of this study is to present an efficient measurement method of the effective thermal diffusivity for the fibrous insulation material. The non-linear parameter estimation (NPE) method is adapted for this analysis because of its accuracy and its results are compared with those by other direct methods such as CTP, CHP and STD method. A experimental system is constructed with bell-jar vaccum chamber, diffusion pump, tube type furnace, control unit and data acquisition system included with A/D converter and IBM XT/AT personal computer. The typical results obtained from this study are as follows; 1) NPE method can be recommended as an useful and accurate method to measure the effective thermal diffusivity of insuation material because it is shown that the measurement error compared with those by other direct methods is reduced for standard material, NBS-1450b. 2) NPE method can minimize the effects of ill-measured temperature due to external disturbance, because the final value is found by point to point estimating. 3) NPE method dose not depend on the kinds of heat flux, since the surfac temperature are used to estimate the thermal diffusivity. 4) With NPE method, compared with the steady state method, a measuring time and a sample size could be reduced.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.06a
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• pp.373-377
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• 2005

The work of hairdressers includes washing, coloring, bleaching, permanent waving, conditioning, and cutting hair. Hairdressers are subjected to a number of physical and toxicological hazards. The toxicological hazards are those resulting from exposure to a wide range of chemicals and from chemicals are usually classified active processes. In this study, twenty beauty shops were selected to assess the exposure to indoor air pollutants such as VOCS and particulate matter($PM_{10}$) during one month from September 1 to September 30, 2003. Indoor air quality of beauty shops might be worse by vehicle emissions because the beauty shops were generally located near roadways. Personal exposures to VOCs and PM lo were related to indoor concentrations of beauty shops. According to the questionnaire, hairdressers complained of sore throat, eye irritation, and nervousness as physical symptoms. Conclusively, customers as well as workers in the beauty shops might be highly exposed to air pollutants from indoor sources and outdoor sources. Therefore, proper management methods should be taken to improve the indoor air quality in beauty shops.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.5
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• pp.680-690
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• 2014

This study investigated the performance of hygiene management according to the capacity and food cost of foodservice in kindergartens as a measure of kindergartens foodservice hygiene management. Dietitians from the education office visited 50 kindergartens under the control of Dongbu District Office of Education during January, 2011. Kindergartens were 11 public and 39 private institutions. Over half of kindergartens (n=27) provided foodservice to 50~99 children. About 21 kindergartens had a foodservice cost per student per day of 2,000 won. Regarding personal hygiene, 'whether to wear an accessory or have a manicure' showed the best performance. 'Whether to have their health examined once every 6 months or keep their health records in 2 years' was rarely performed. For food materials, 'whether to buy food appropriate for the quality control standard of food materials' showed the highest performance. The highest performances for storage management of food materials and handling of food was 'whether to store goods within butlery at intervals more than 30 cm from the ground' and 'whether to heat and cook food more than $74^{\circ}C$', respectively. The highest performance for distribution of food and management of facilities was 'the hygienic management of cooking tools and facilities' and 'the proper installation of air-conditioning, heating and ventilation facilities', respectively. The results of this study show that capacity and food cost had the strongest effects on performance of personal hygiene. Especially, smaller facility size could increase performance of foodservice management.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.8 no.4
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• pp.463-472
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• 1996

Experiments were carried out to study the operation characteristics of a regenerator with a thermo-syphon pump and a surface-flame burner for a lithium bromide (LiBr)-water absorption heat pump. A cylindrical-shape metal-fiber burner and commercial grade propane were used. The emission of carbon monoxide and nitric oxide was measured by a combustion gas analyzer. Ther regeneration rate of water vapor as a refrigerant was measured. It could be as a reference value showing the performance of the regenerator. The circulation rate of the LiBr-water solution was also measured from both the tanks for the weak-and the strong-solution. Using a refractometer, the LiBr concetration in the solution was calculated from the measured refractory index of the solution. Temperature of the solution and the condensed water was recorded at several points in the experimental apparatus with thermocouples, using a personal computer. This data collecting system for measuring temperature was calibrated with a set of standard thermometers. The generating rate of water vapor as refrigerant increased linearly with heat supplied. It was about 4.0g/s with the heat supplied at a rate of 16,500kcal/h. The circulation rate of LiBr solution also increases with the heat supplied. The difference in LiBr concentrations between the weak and the strong solution was in the range of 1 to 5% when the concentration of the strong solution was about 60%. It was dependent upon both the heat supplied and the circulation rate of the solution. The initial concentration and the level of the LiBr solution in the regenerator were measured and recorded before experiments. The effect of them on the generating rate of water vapor and the circulation rate of the solution was also studied. The generating rate of water vapor was not strongly dependent upon both the level of the LiBr solution and the initial LiBr concentration. However, the concentration difference of the solution increases with the initial level of the LiBr solution.

• Proceedings of the SAREK Conference
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• 2008.11a
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• pp.95-98
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• 2008

A power line communications, power, the outgoing line is a means of communication. DC 12 volt power lines in the system over the 2-wire control signals with the power to send the cargo configuration, and, in the basement living space, temperature, humidity, dust, CO2 sensors, and through the cooperation of the real-time detection and valves of the appropriate amount of wind, fan was designed to control. By the system's ability to communicate and control the room temperature or the status of amount of wind sent to the central system to transmit and receive signals to the center of the future, the ability to control the company said. In addition, the system HMI (Human Machine Interface) terminal by the direct control and if necessary personal portable devices to communicate with the living conditions of the underground environment in the best state that the purpose is to build.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1977-1987
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• 2008

In this paper, presented was the research work of finding practical application systems using IT that would be adopted by the next generation high speed train for the safety, convenience, and comfort of the passengers and crew members. Study on the applications using smart sensors and IT brought up 26 feasible application cases. Among them 16 cases were related with IT applications and 10 cases smart sensor applications. After having public hearings and surveys to make the decision more objective and generally acceptable, 7 applications - such as information providing service using personal LCD monitor, alarm service, individual internet access service, automatic and remote air conditioning, wireless visual communication with an attendant, extraordinary sound detection, urgent situation in toilet monitoring - out of those 26 were chosen as the final applications.

• Journal of Environmental Science International
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• v.26 no.9
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• pp.1013-1021
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• 2017

Exposure to Diesel Particulate Matter (DPM) potentially causes adverse health effects (e.g. respiratory symptoms, lung cancer). Due to a lack of data on Elemental Carbon (EC) exposure levels in underground copper ore mining (unlike other underground mining industries such as non-metallic and coal mining), this case study aims to provide individual miners' EC exposure levels, and information on their work practices including use of personal protective equipment. EC measurement was carried out during different work activities (i.e. drilling, driving a loader, plant fitting, plant operation, driving a Specialized Mining Vehicle (SMV)) as per NIOSH Method 5040. The copper miners were working 10 h/day and 5 days/week. This study found that the most significant exposures to EC were reported from driving a loader (range $0.02-0.42mg/m^3$). Even though there were control systems (i.e. water tanks and DPM filters) on the diesel vehicles, around 49.5% of the results were over the adjusted recommendable exposure limit ($0.078mg/m^3$). This was probably due to: (1) driver's frequently getting in and out of the diesel vehicles and opening the windows of the diesel vehicles, and (2) inappropriate maintenance of the diesel vehicles and the DPM control systems. The use of the P2 type respirator provided was less than 19.2%. However, there was no significant difference between the day shift results and the night shift results. In order to prevent or minimize exposure to EC in the copper ore mine, it is recommended that the miners are educated in the need to wear the appropriate respirator provided during their work shifts, and to maintain the diesel engine and emission control systems on a regular basis. Consideration should be given to a specific examination of the diesel vehicles' air-conditioning filters and the air ventilation system to control excessive airborne contaminants in the underground copper mine.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.236-248
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• 2020

Objectives: The purpose of this study was to evaluate the concentrations of particulate matter generated during coffee roasting and to study various factors affecting the concentrations. Methods: Differences in concentration levels were investigated based on various factors to understand the emission rates of particulate matter over time and to compare the mass and number concentrations according to their size. Sampling was performed in closed laboratories without the operation of air conditioning or ventilation. Optical Particle Sizer(OPS) was used as a measuring device. An OPS measures using a light-scattering method. Sampling was performed for sixty minutes at one-minute intervals. The background concentration was measured for about 30 minutes before starting of coffee roasting. The concentrations of particulate matter generated during coffee roasting were monitored until roasted coffee beans were removed from the roaster and cooled down. Several factors affecting the concentrations of particulate matter were investigated, which includes the origins of green beans, the roasting level, and the input amount of green beans. Results: The results of this study may be summarized as follows: 1) There was no difference in particulate matter concentration levels by the origin of the green beans, but a statistically significant difference in concentration levels by roasting level and the input amount of green beans; The higher the roasting level, the higher was the particulate matter concentration. The more green beans we put in the roaster, the higher were the concentrations; 2) The PM10 mass concentrations increased over time. The average concentration after roasting was higher than the average concentration during roasting; 3) In the distribution of mass and number concentration by particle diameter, the majority of particles was below 2.5 ㎛. Conclusions: Persons who work in roastery cafes can be exposed to high concentrations of particulate matter. Therefore, personal exposure and risk assessment should be conducted for roastery cafe workers.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.845-847
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• 2014

In recent years, the mobile OS market, enlargement and, at the same time, Android has mounted various smart phones and feature air conditioning, smart TV, cleaning robot, camera, etc. that the number is being spread at a rapid pace. But a lot of devices to control the modules and applications at once, this is not a device for controlling the dissemination of applications all in one place, and in charge of the devices that allow you to manage applications are lacking. Accordingly, in this paper, use the Web Server registered in the appliance can be controlled by management, Web access, is proposing and designing the system. This is the current research is actively in progress in the field of IoT (Internet of Things) would be utilized.