• Journal of the Ergonomics Society of Korea
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• v.34 no.5
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• pp.519-529
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• 2015

Objective: This study aims to analyze the characteristics of occupational accidents and injuries of telecommunications line and cable workers by type of workplace and operational process of cabling service and to provide baseline data in establishing the preventive policies for occupational accidents and injuries. Background: In order to set up the preventive policies for occupational injuries and illness systematically, the accident analysis by industry should be preceded. To establish more effective policies, it should be done by occupation for persons who work in various kinds of occupation rather than by industry for persons who do in the same occupation. Method: In this study, the 176 occupational accidents and injuries were classified by type of workplace - indoor (inside building) and outdoor (at the top of utility pole, in a manhole, or in the fields) - and also done by operational process involved at the time of the accident. By analyzing the characteristics of occupational injuries and illness by type of workplace and operational process, respectively, this study can be helpful in establishing the preventative policies for occupational accidents and injuries. Results: The characteristics of occupational accidents and injuries by type of workplace showed that there were differences in terms of accident rate between indoor and outdoor on age of the injured, while not on employment-size and work experience of the injured. In addition, the characteristics on accident type, agency of accident, parts of body affected, and operational process between indoor and outdoor workplaces were statistically different each other. Conclusion and Application: The findings of occupational accidents' characteristics can be applied to the establishment of systematic preventative policies for occupational accidents of telecommunications line/equipment workers.

• Korean Journal of Childcare and Education
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• v.9 no.4
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• pp.185-210
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• 2013

The purpose of the study was to observe and categorize daily routines of infant classes in daycare centers based on quantity of indoor and outdoor free play, group activities and nap/rest and explore differences in infants' play and teacher's behavior according to daily routine types. A team of trained observer observed daily routines and teacher's behavior of 26 infant classes from 7 daycare centers for two days and teachers evaluated 164 infants' playfulness. As a result daily routines of infant classes were categorized into two types: "Indoor & Outdoor Free Play Oriented" and "Group Activities & Rest Oriented". Infants' playfulness of "Indoor & Outdoor Free Play Oriented" groups were higher than that of "Group Activities & Rest Oriented" groups. Teachers from "Indoor & Outdoor Free Play Oriented" groups were found to have more experiences in the field and also they showed more positive and neutral guidance than the others.

• Journal of environmental and Sanitary engineering
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• v.16 no.4
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• pp.21-30
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• 2001

Vehicles, especially diesel-using, are a major source of airborne particulate matter(PM), nitrogen dioxide($NO_2$) and so on in metropolitan cities such as Seoul. Therefore workers, who are mainly merchants, near roadside may be highly exposed to air pollutants from exhausted emissions of vehicles. This means that occupational type and location can affect the workers＇health by exposure to outdoor pollutions of ambient as well as indoor pollutions of working condition, respectively. In this study, we simultaneously measured the PM3.5 and $NO_2$concentrations in indoor and outdoor of shoes repair shops in Seoul, which were generally located at roadside in Korea. Shoes repairmen were highly exposed to PM3.5 and $NO_2$ both indoor and outdoor of repair shops comparing with other sub-population groups. High exposure to air pollutants for shoes repairmen was considered to be outdoor source from exhausted emission of vehicles and indoor source from working condition. The $PM3.5/NO_2$ concentration ratio was $1.17{\pm}$0.59 in roadside, of which ratio was higher 7han ratios of other studies. This result suggested that major air pollutant in Seoul was fine particle. Also, this PM3.5 to $NO_2$ ratio will be used in environmental exposure and risk assessment by estimation of PM3.5 concentration as measuring the only $NO_2$ concentration with small and accurate $NO_2$ passive sampler.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.8
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• pp.1789-1794
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• 2009

In the present study, the cooling performance characteristics on environment changes of A/C applied fin-tube and PF heat exchangers were experimentally investigated. Capacity and COP on an air velocity, an indoor/outdoor temperature and an indoor/outdoor relative humidity were obtained. Fin types of PF heat exchanger were a triangler and squarer form. The experimental data for the three kinds of heat exchangers were measured using the air-enthalpy calorimeter. Performance of PF A/C was more excellent than that of a fin-tube A/C. Also, the performance of PF-2 A/C with the squarer fin was more excellent than that of PF-1 A/C with the triangler fin. As the air velocity, the indoor temperature and the indoor relative humidity increase, capacity and COP increase. And as outdoor temperature increases, capacity and COP decrease. But, the performance change on the outdoor relative humidity was insignificant.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1149-1154
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• 2022

The purpose of this research is to select representative observation stations for winter observation equipment performance tests and to present indoor and outdoor conditions for performance tests by considering snowfall, snowfall days, latitude, and altitude distribution for observation stations operated by the Korea Meteorological Administration. Using the snowfall data observed during the winter for 30 years (1981-2010), ten representative observation stations are selected to consider the classification of snowfall days by class, latitude, and altitude distribution of observation stations. As a result of analysis, the suitable point for outdoor experiments was selected as Daegwallyeong, the average number of snowfall days and snowfall days of 5cm or more were 57.5 and 13.2 days, respectively. The indoor experimental conditions are considered to be suitable under temperatures of -15 to 5℃ and humidity of 50% or higher. Results of this research can be used as basic information for conditions and test beds for performance tests of equipment that can respond to heavy snow disasters in winter.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.8
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• pp.1655-1666
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• 2015

In this paper, user-position estimation method is proposed by using a single camera for both indoor and outdoor environments. Conventionally, the GPS of RF-based estimation methods have been widely studied in the literature for outdoor and indoor environments, respectively. Each method is useful only for indoor or outdoor environment. In this context, this study adopts a vision-based approach which can be commonly applicable to both environments. Since the distance or position cannot be extracted from a single still image, the reference images pro-stored in image database are used to identify the current position from the single still image captured by a single camera. The reference image is tagged with its captured position. To find the reference image which is the most similar to the current image, the SURF algorithm is used for feature extraction. The outliers in extracted features are discarded by using RANSAC algorithm. The performance of the proposed method is evaluated for two buildings and their outsides for both indoor and outdoor environments, respectively.

• Environmental Analysis Health and Toxicology
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• v.21 no.1 s.52
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• pp.57-69
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• 2006

Lately human exposure to fine particles smaller than $2.5{\mu}m$ in aerodynamic diameter ($PM_{2.5}$) has become a great concern in Korea due to their possible cause of elevated mortality, lung function decrements, and more frequent hospital admissions for asthma. This study was conducted to investigate seasonal variations of human exposure to residential $PM_{2.5}$ and particle-associated polycyclic aromatic hydrocarbons (PAHs). Ten homes in Chuncheon, Korea were visited for continuous 72 hour sampling of $PM_{2.5}$ in the living rooms using a MiniVol Portable Sampler from December 22, 2002 to November 3, 2003. During the same period, outdoor $PM_{2.5}$ samples were collected on the top of the Natural Sciences Building of Kangwon National University which is located in the middle of the ten households. Samples were analyzed for $PM_{2.5}$ mass concentrations and six selected PAHs. In two smoking homes, the highest $PM_{2.5}$ concentrations were measured ranging from 51.1 to 69.7 {\mu}g/m^3$ on average in all seasons, indicating smoking is a very important contributor to the elevation of indoor particle concentrations. Seasonal comparison showed that indoor particle concentrations were higher than outdoor ones except winter. Total PAH concentrations in smoking homes were highest in winter among the seasons primarily due to low ventilation rate, followed by the outdoor site and nonsmoking homes. BaP toxic equivalents (TEQs) were calculated for five PAHs. The TEQ for smoking homes in winter was highest followed by the outdoor site in winter. It is concluded that smoking and ventilation rate are two important contributors to the elevation of indoor $PM_{2.5}$ and PAH concentrations.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.7 no.2
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• pp.37-42
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• 2011

Dedicated outdoor air(DOA) system which conditions the outdoor air separately is superior to conventional Cooling + reheating system with respect to energy consumption and indoor comfort. Since the sensible and latent load characteristics of indoor and outdoor are different, it is more efficient to treat them separately. In this study, cycle analysis and on-site performance test of DOA system have been conducted. The study shows that DOA requires 50% less equivalent energy than the conventional system. The on-site performance test of a prototype shows that the coefficient of performance(COP) of the DOA system is 37% higher than the conventional system.

• Korean Journal of Clinical Laboratory Science
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• v.41 no.3
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• pp.105-110
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• 2009

Yellow sand (or Asian dust) occurs mainly in spring in East Asia. Yellow sand from China and its surrounding regions transports air pollutants, such as aerosols, ozone, and heavy metals. The outdoor workers are frequently exposed to heavy metals during yellow sand phenomenon. This study was carried out to investigate the heavy metal levels in blood among 75 outdoor workers (exposed group) and 86 indoor workers (controled group) in Gyeonggi province from March 2008 to May 2009. Heavy metal levels in blood were analyzed by atomic absorption spectrophotometer. Mean blood lead levels in exposed group and controled group were $5.19{\pm}1.64{\mu}g/dL$, $4.24{\pm}1.34{\mu}g/dL$, respectively. Mean blood cadmium levels in exposed group and controled group were $1.28{\pm}0.89{\mu}g/dL$, $0.90{\pm}0.59{\mu}g/dL$, respectively. Lead and Cadmium levels in blood of exposed group were significantly higher than those of controled group. In the comparison of smoking status, lead and cadmium levels of smokers were significantly higher than those of non-smokers. In conclusion, the heavy metal levels of outdoor workers were significantly higher than those of indoor workers. And smoking was hazardous factor to elevate heavy metal levels in blood.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.48-55
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• 2009

Prior research works in indoor-outdoor classification have been conducted based on a simple combination of low-level features. However, since there are many challenging problems due to the extreme variability of the scene contents, most methods proposed recently tend to combine the low-level features with high-level information such as the presence of trees and sky. To extract these regions from videos, we need to conduct additional tasks, which may yield the increasing number of feature dimensions or computational burden. Therefore, an efficient indoor-outdoor scene classification method is proposed in this paper. First, the video is divided into the five same-sized blocks. Then we define and use the edge and color orientation histogram (ECOH) descriptors to represent each sub-block efficiently. Finally, all ECOH values are simply concatenated to generated the feature vector. To justify the efficiency and robustness of the proposed method, a diverse database of over 1200 videos is evaluated. Moreover, we improve the classification performance by using different weight values determined through the learning process.