• Environmental Engineering Research
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• v.18 no.4
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• pp.253-257
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• 2013

Exposure assessment for three major active ingredients used for humidifier disinfectants, polyhexamethylene guanidine (PHMG), oligo(2-(2-ethoxy)ethoxyethyl guanidinium chloride (PGH), and 5-chloro-2-methylisothiazol-3(2H)-one/2-methylisothiazol-3(2H)-one (CMIT/MIT) mixture, was conducted in a bedroom using an air sampler for a refined risk assessment. The experimental site was selected to reflect consumer exposure conditions. Aerosols formed by a humidifier were sampled during 8 hr at 7.5 L/min. Absorbed PHMG and PGH by the sampler were quantified using a spectrophotometric method, and high performance liquid chromatography-ultraviolet detection was used for CMIT/MIT. Three exposure scenarios were assumed for adding humidifier disinfectants to the humidifier water at 1, 2, and 10 times the volume recommended by the product suppliers, and the humidifier was on at its maximum rate of producing aerosols in order to consider reasonable worst-cases. The sampled mass of PHMG and PGH ranged 200 to $2,800{\mu}g$ and 140 to $1,900{\mu}g$, respectively, under different exposure conditions, whereas the absorbed mass of CMIT/MIT was barely detected at the detection limit of 0.11/0.29 mg/L, only at 10 times the recommended level. The resulting risk quotients for PHMG and PGH ranged 1,400 to 20,000 and 1,000 to 13,000, indicating that health risks could be significant. For CMIT/MIT mixture, risk quotients were much smaller than estimated by assuming that they are conservative in the indoor environment, probably due to oxidative reactions. The refined exposure assessment presented here may provide a useful tool for assessing risks posed by active ingredients in spray-type biocidal products.

• Journal of the Korean Home Economics Association
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• v.46 no.1
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• pp.47-61
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• 2008

The purpose of this study is to provide information about domestic living of Korean immigrants in Australia and Canada who have the same cultural background for comparative study. For this, usage of domestic space and living style in housing of 52 Korean households in Melbourne of Australia and 32 Korean households in the region of Waterloo of Canada were analyzed. Ethnographic research with questionnaire were used. Results of the research were as follows. 1. Korean immigrants in each countries were living in houses which was built by company of Australia and Canada. 44.2% of Korean immigrants in Australia were using L+D K and 53.1% of Korean immigrants in Canada were using L D K. 2. Laundry was indispensable for Korean immigrants in both countries and they all wanted to use the laundry as a utility room which could dry, ironing and so on. 3. Drain hole on the floor of the bathroom was not indispensable for most Korean immigrants in both countries for hygienic reason. 4. Korean immigrants in both countries were ironing in master bedroom and they all wanted to separate it from there through renovation and extension and so on. 5. Korean immigrants in Canada were more active to use the formal lounge which has been planned as a traditional element of western house. 6. The seating style of Korean immigrants in both countries belong to chair-seating style mostly. But it was clear that they were making Kimchi with floor seating style in both countries. 7. A level of satisfaction about using carpet was not high for Korean immigrants in both countries cause of uneasiness to clean and it was considered to relate to the floor seating style of them. 8. Almost Korean immigrants were took off the shoes inside of the house and they had shoes cabinet beside the entrance or basement usually. 9. The most popular heating system was ducted heating in both countries. The level of satisfaction about this was different for Korean immigrants in Australia and Canada but most desirable heating system was Ondol for them in both countries commonly.

• Journal of the Korean association of regional geographers
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• v.3 no.1
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• pp.13-34
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• 1997

The impact of a central place on daily living over wide outlying territory has been one of traditional subjects in the field of urban geography. The flow of rural population toward the central city of Chinju characterizes the population movement in Western Kyungnam, where the spillover of urban population into outlying areas, an especially prominent phenomenon in American society, does not occur. The central city of Chinju is supposed to be the most favored settlement area in Western Kyungnam. More than two thousands of teachers. who live in Chinju, cross the city boundary each morning to do their jobs in Western Kyungnam. But only ninety teachers living outside Chinju commute to the workplace in the city. The teachers willingly spend hours commuting each day to enjoy better quality of life in the central city. In fact, the central city of Chinju functions as bedroom communities for many middle-class workers in Western Kyungnam. On the basis of teachers' commuting behavior, four levels of Chinju's urban spheres are identified in Western Kyungnam. As Table-6 and Figure-2 show, the first-order level of Chinju's sphere includes most Myuns of Sanchung/Hadong Guns and some Myuns of Sachun/Gosung Guns. The second-order level comprises Sanchung/Sachun Eubs and many Myuns of Sachun /Gosung Guns. The third-order level is made up of Samchunpo, Hadong/Gosung/Eryung/Namhae/Habchun/Hamyang Eups, and many Myuns of Eryung/Namhae/Habchun Guns. And all of Guchang Gun and most Myuns of Hamyang Gun belong to the fourth-order level of Chinju's sphere. The influence sphere of Metropolitan Chinju is extended farther in the direction of less competition with other metropolises. Such a situation occurs to the west and south of Chinju. Daily commuting, defined as the journeys to and from work, is an excellent indicator for delimiting urban spheres of influence.

• Journal of health informatics and statistics
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• v.42 no.4
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• pp.309-316
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• 2017

Objectives: Radon and its progeny pose environmental risks as a carcinogen, especially to the lungs. Investigating factors affecting indoor radon concentrations and models thereof are needed to prevent exposure to radon and to reduce indoor radon concentrations. The purpose of this study was to identify factors affecting indoor radon concentration and to construct a comprehensive model thereof. Methods: Questionnaires were administered to obtain data on residential environments, including building materials and life style. Decision tree and structural equation modeling were applied to predict residences at risk for higher radon concentrations and to develop the comprehensive model. Results: Greenery ratio, impermeable layer ratio, residence at ground level, daily ventilation, long-term heating, crack around the measuring device, and bedroom were significantly shown to be predictive factors of higher indoor radon concentrations. Daily ventilation reduced the probability of homes having indoor radon concentrations ${\geq}200Bq/m^3$ by 11.6%. Meanwhile, a greenery ratio ${\geq}65%$ without daily ventilation increased this probability by 15.3% compared to daily ventilation. The constructed model indicated greenery ratio and ventilation rate directly affecting indoor radon concentrations. Conclusions: Our model highlights the combined influences of geographical properties, groundwater, and lifestyle factors of an individual resident on indoor radon concentrations in Korea.

• Land and Housing Review
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• v.14 no.3
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• pp.17-36
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• 2023

This research aims to investigate the socio-demographic, financial, and housing statuses of young married couples in Chonsei housing and to analyze the determinants of their residential environment quality and housing expenditure in four districts - Seoul and Gyeonggi-Incheon Area(GIA) of the Seoul Metropolitan Area(SMA), and metropolises and non-metropolises of non-SMA. From the 2020 Korean Housing Survey(KHS), this cross-sectional analysis examined a sample of 691 households, and the findings revealed that most were headed by college-educated, salaried male workers aged 31 years old. While childless dual-earner couples were common in Seoul, single-income families of three were prevalent in non-SMA. The financial status of the couples in Seoul was a lot better than in the other three areas, particularly much higher in Chonsei deposit and total asset value. Further, many lived in a three-bedroom apartment unit sized 60m² and bigger, using a Chonsei loan. Regardless of areas, almost all the households spent a very low portion of their living expenses and income on housing costs. However, dual-earner families positively increased borrowing capacity, which improves the household's financial position that is likely to lead to equity increment in a volatile asset market in the long run. The statistical results indicated that residential environment assessment was influenced by neighborhood quality and housing expenditure was affected by housing size in Seoul, urban amenities in GIA and householder's gender in non-metropolises. Thus, this research proposes that strong measures be considered to mitigate housing inequality embedded in geographical and socio-economic disparities.

• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.341-351
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• 2019

This study examines factors related to the safety of housing for elderly people. Because of the diverse problems that may occur due to aging, elderly residents may have special needs related to housing. To identify relevant factors, first, focus group interviews were conducted with six individuals aged 65 or older. Then, a Delphi survey was conducted on experts; this survey consisted of a questionnaire on factors related to the safety of housing for elderly people. Issues to address in the questionnaire were identified in the focus group interviews and also through an examination of literature published domestically and overseas. In the Delphi survey, opinions were collected from the experts; these opinions were then revised, collated, and analyzed. The factors identified in these steps were verified using a content validity index. As a result, a total of seven primary factors - outdoor environment, entrance, indoor environment, living room, bedroom, kitchen, bathroom, and restroom - and 23 sub-factors related to elderly people's housing safety were identified. The most frequently mentioned factors were indoor and outdoor stairs, safe flooring materials, and indoor thresholds. It is essential to identify the factors that most affect the safety of elderly people in their residences.

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.1
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• pp.70-81
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• 2024

In this study, Tridimensional Hybrid Isolation System(THIS) was proposed as a vibration isolator for traffic loads, combining vertical and horizontal isolation systems. Its efficacy in improving serviceability for vertical vibration was analytically evaluated. Firstly, for the analysis, the major vibration modes of the existing apartment were identified through eigenvalue analysis for the system and pulse response analysis for the bedroom slab using commercial structural analysis software. Subsequently, a 16-story model with horizontal, vertical and rotational degrees of freedom for each slab was numerically organized to represent the achieved modes. The dynamic analysis for the measured acceleration from an adjacent ground to high-speed railway was performed by state-space equations with the stiffness and damping ratio of THIS as variables. The result indicated that as the vertical period ratio increased, the threshold period ratio where the slab response started to be suppressed varied. Specifically, when the period ratio is greater than or equal to 5, the acceleration levels of all slabs decreased to approximately 70% or less compared to the non-isolated condition. On the other hand, it was ascertained that the influence of damping ratios on the response control of THIS is inconsequential in the analysis. Finally, the improvement in vertical vibration performance of THIS was evaluated according to design guidelines for floor vibration of AIJ, SCI and AISC. It was confirmed that, after the application of THIS, the residential performance criteria were met, whereas the non-isolated structure failed to satisfy them.

• Journal of Korean Society of Disaster and Security
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• v.9 no.2
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• pp.53-62
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• 2016

This paper is shown the new method using LED Light, which the light environment is upgraded the natural LED light in the area of Disaster Prevention and Safety Management (PDSD), which the events of deaths is reduced on the Suicide, the Infectious diseases, the safety accidents, the Traffic Accident, the crime, the fire, the Nature Disaster, and which the health and the environment and the safety is implemented using the value of the color LED Light. Research findings include,during 3 weeks in the November 2016, in the ten residents (average living 28.7 years, age 67.5 years) with depressive symptoms in the northern part of Seoul, according to the request of the user, the PDSD natural light LED lighting was installed in the home bedroom or the living room, expectations for the ability to restore physical and mental stability were high (88%), in the same way, after 1 week and 3 weeks, the physical and mental changes were compared and the results,84% in the first week and 90% in the third week and thereafter, the effect of relieving depression was high. We conclude that patients with depression have a good sleep, an uneasy feeling, a sense of security, a good night's sleep, and a good feeling. The PDSD LED Light is expected to contribute in the various areas, which reduced the suicides, which give increased immunity from infectious diseases, which give a crash to reduce accidents caused by negligence, which improve the safe operation of heavy vehicles in which a traffics accident incidence installed on the highest point, which improve the safety function on the 'safety way home' for the safety of the community, which due to fire gives alleviate the emotional anxiety of firefighters, which improve the environment for long-term control room working during decision making caused by natural disasters.

• Journal of Global Scholars of Marketing Science
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• v.17 no.3
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• pp.1-19
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• 2007

1. Purpose Rural tourism is made by individuals with different characteristics, needs and wants. It is important to have information on the characteristics and preferences of the consumers of the different types of existing rural accommodation. The stud aims to identify the determinants of consumer preference by type of accommodations. 2. Methodology 2.1 Sample Data were collected from 1000 people by telephone survey with three-stage stratified random sampling in seven metropolitan areas in Korea. Respondents were chosen by sampling internal on telephone book published in 2006. We surveyed from four to ten-thirty 0'clock afternoon so as to systematic sampling considering respondents' life cycle. 2.2 Two-step cluster Analysis Our study is accomplished through the use of a two-step cluster method to classify the accommodation in a reduced number of groups, so that each group constitutes a type. This method had been suggested as appropriate in clustering large data sets with mixed attributes. The method is based on a distance measure that enables data with both continuous and categorical attributes to be clustered. This is derived from a probabilistic model in which the distance between two clusters in equivalent to the decrease in log-likelihood function as a result of merging. 2.3 Multinomial Logit Analysis The estimation of a Multionmial Logit model determines the characteristics of tourist who is most likely to opt for each type of accommodation. The Multinomial Logit model constitutes an appropriate framework to explore and explain choice process where the choice set consists of more than two alternatives. Due to its ease and quick estimation of parameters, the Multinomial Logit model has been used for many empirical studies of choice in tourism. 3. Findings The auto-clustering algorithm indicated that a five-cluster solution was the best model, because it minimized the BIC value and the change in them between adjacent numbers of clusters. The accommodation establishments can be classified into five types: Traditional House, Typical Farmhouse, Farmstay house for group Tour, Log Cabin for Family, and Log Cabin for Individuals. Group 1 (Traditional House) includes mainly the large accommodation establishments, i.e. those with ondoll style room providing meals and one shower room on family tourist, of original construction style house. Group 2 (Typical Farmhouse) encompasses accommodation establishments of Ondoll rooms and each bathroom providing meals. It includes, in other words, the tourist accommodations Known as "rural houses." Group 3 (Farmstay House for Group) has accommodation establishments of Ondoll rooms not providing meals and self cooking facilities, large room size over five persons. Group 4 (Log Cabin for Family) includes mainly the popular accommodation establishments, i.e. those with Ondoll style room with on shower room on family tourist, of western styled log house. While the accommodations in this group are not defined as regards type of construction, the group does include all the original Korean style construction, Finally, group 5 (Log Cabin for Individuals)includes those accommodations that are bedroom western styled wooden house with each bathroom. First Multinomial Logit model is estimated including all the explicative variables considered and taking accommodation group 2 as base alternative. The results show that the variables and the estimated values of the parameters for the model giving the probability of each of the five different types of accommodation available in rural tourism village in Korea, according to the socio-economic and trip related characteristics of the individuals. An initial observation of the analysis reveals that none of variables income, the number of journey, distance, and residential style of house is explicative in the choice of rural accommodation. The age and accompany variables are significant for accommodation establishment of group 1. The education and rural residential experience variables are significant for accommodation establishment of groups 4 and 5. The expenditure and marital status variables are significant for accommodation establishment of group 4. The gender and occupation variable are significant for accommodation establishment of group 3. The loyalty variable is significant for accommodation establishment of groups 3 and 4. The study indicates that significant differences exist among the individuals who choose each type of accommodation at a destination. From this investigation is evident that several profiles of tourists can be attracted by a rural destination according to the types of existing accommodations at this destination. Besides, the tourist profiles may be used as the basis for investment policy and promotion for each type of accommodation, making use in each case of the variables that indicate a greater likelihood of influencing the tourist choice of accommodation.

• Journal of Preventive Medicine and Public Health
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• v.21 no.1 s.23
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• pp.132-151
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• 1988

This study was conducted to establish the control program for preventing unfavorable health effects of nitrogen dioxide($NO_2$) exposure in homes by preparing the fundamental data for evaluation of relation-ships between $NO_2$ levels and influencing factors through measurements of indoor-outdoor $NO_2$ levels and personal $NO_2$ exposures for housewives with questionnaire survey on 172 homes in Pusan area from April to June, 1987 $NO_2$ measurements were made by using diffusion tube samplers(Palmes tube $NO_2$ sampler) for one week at 4 sites in homes ; kitchen(KIT), bedroom(BED), living room(LIV), outdoor(OUT) and near the collar of housewives(personal exposure livel, PNO). The details of questionnaire were number of household members(FAM), number of regular smokers (SMOKER), daily number of meals eaten(MEAL), type of housing units(HOUSE), location of house with distance from the heavy traffic roads as walking time(DIST), and of kitchen(KAREA), kind of cooking fuels(FUEL), cooking time of each meal(CTIME), usage of kitchen fan for cooking(FAN), type of heating facilities(HEAT) and so on of subject homes. The Obtained results were as fellows : 1) The mean $NO_2$ level was significantly higher at indoors than outdoors(p<0.01) and the kitchen $NO_2$ level was the highest with $33.7{\pm}13.6ppb$(9.5-81.5ppb). The mean personal exposure level of $NO_2$ for housewives was $20.6{\pm}8.8ppb$(3.1-46.9ppb). 2) The mean indoor $NO_2$ level was significantly higher in the group of household members above 5 than below 4(p<0.05), in detached dwellings than apartments(p<0.001), within 5 minutes of distance than over 5 minutes(p<0.001), in the group of unusing fan(p<0.001), in the group of longer cooking time(p<0.001), and it was in order of coal briquette, gas, electricity and oil by kind of cooking fuels(p<0.05). 3) Variables showing significant correlation(p<0.001) with indoor $NO_2$ level were kitchen $NO_2$ level(r=0.8677), cooking time(r=0.5921), outdoor $NO_2$ level(r=0.5192), personal $NO_2$ exposure level(r=0.4615), usage of kitchen fan(r=0.3573) and location of house(r=-0.2988) 4) As a result of multiple regression analysis, the most significant influencing variable to the kitchen $NO_2$ level was cooking time[KIT=$-0.378{\pm}11.772$(CTIME)+0.298(OUT)+3.102(FAN)], it was kitchen $NO_2$ level to the indoor $NO_2$ level[IND=6.996+0.458(KIT)+0.230(OUT)-1.127(KAREA)], and it was indoor $NO_2$ level to the personal $NO_2$ exposure level[PNO=15.562+0.729(IND)-4.542(DIST)-0.200(KIT)] 5) It was recognized that aritificial ventilation in the kitchen, suppression of unnecessary combustion and replacement of cooking fuel, as much as possible, were effective means for decreasing indoor $NO_2$ levels in homes.