• Journal of radiological science and technology
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• v.27 no.2
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• pp.29-33
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• 2004

Until early 1980s we have lived without thinking that radon ruins our health. But, scientists knew truth that radon radioactive danger is bedeviling on indoor that we live for a long time. Specially, interest about effect that get in danger and injury for Radon and human body is inactive in our country. Recently, with awareness for Radon contamination, We inform about importance and danger of Radon in some station of the Seoul subway, indoor air of school facilities and We had interest with measure and manages. Usually, Radon gas emitted in base of building enters into indoor through building floor split windage back among radon or indoor air of radon daughter nucleus contamination is increased. Therefore, indoor radon concentration rises as there are a lot of windages between number pipe of top and bottom and base that enter crack from estrangement of the done building floor, underground to indoor. Thus, Radon enters into indoor through architecture resources water as well as, kitchen natural gas for choice etc., but more than about 85% from earth's crust emit. Danger and injury of health by Radon and Radon daughter nucleus that is indicated for cause of lung cancer incerases content of uranium of soil rises specially from inside pit of High area and a mine, cave, hermetical space with house. Safe sub-officer of radon concentration can not know and danger always exists large or small during. So, Important thing reduces danger of lung cancer by lowering concentration of Radon within house and building. Therefore, is thought that need general house Radon concentration measurement, measured Radon concentration monthly using Sintillator radon monitor. Study finding appeared high all underground market 1 year than the ground, and the winter appeared high than the summer. Specially, month that pass over 4pCi in house that United States Environmental Protection Agency advises appeared in underground, and appeared and know Radon exposure gravity by 4 months during 12 months. Therefore, Thinking that establishment and regulation of norm and preparation of reduction countermeasure about Radon are pressing feels, and inform result that measure Radon concentration.

• Journal of Korea Water Resources Association
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• v.53 no.8
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• pp.627-636
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• 2020

Debris flow disasters primarily occur in mountainous terrains far from cities. As such, they have been underestimated to cause relatively less damage compared with other natural disasters. However, owing to urbanization, several residential areas and major facilities have been built in mountainous regions, and the frequency of debris flow disasters is steadily increasing owing to the increase in rainfall with environmental and climate changes. Thus, the risk of debris flow is on the rise. However, only a few studies have explored the characteristics of flooding and reduction measures for debris flow in areas designated as steep slopes. In this regard, it is necessary to conduct research on securing independent disaster prevention technology, suitable for the environment in South Korea and reflective of the topographical characteristics thereof, and update and improve disaster prevention information. Accordingly, this study aimed to calculate the amount of debris flow, depending on disaster prevention performance targets for regions designated as steep slopes in South Korea, and develop an independent model to not only evaluate the impact of debris flow but also identify debris barriers that are optimal for mitigating damage. To validate the reliability of the two-dimensional debris flow model developed for the evaluation of debris barriers, the model's performance was compared with that of the hydraulic model. Furthermore, a 2-D debris model was constructed in consideration of the regional characteristics around the steep slopes to analyze the flow characteristics of the debris that directly reaches the damaged area. The flow characteristics of the debris delivered downstream were further analyzed, depending on the specifications (height) and installation locations of the debris barriers employed to reduce the damage. The experimental results showed that the reliability of the developed model is satisfactory; further, this study confirmed significant performance degradation of debris barriers in areas where the barriers were installed at a slope of 20° or more, which is the slope at which debris flows occur.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.647-657
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• 2015

To investigate a method for calculation of the heating load for environmental designs of horticultural facilities, measurements of total heating load, infiltration rate, and floor heat flux in a large-scale plastic greenhouse were analyzed comparatively with the calculation results. Effects of ground heat exchange and infiltration loss on the greenhouse heating load were examined. The ranges of the indoor and outdoor temperatures were $13.3{\pm}1.2^{\circ}C$ and $-9.4{\sim}+7.2^{\circ}C$ respectively during the experimental period. It was confirmed that the outdoor temperatures were valid in the range of the design temperatures for the greenhouse heating design in Korea. Average infiltration rate of the experimental greenhouse measured by a gas tracer method was $0.245h^{-1}$. Applying a constant ventilation heat transfer coefficient to the covering area of the greenhouse was found to have a methodological problem in the case of various sizes of greenhouses. Thus, it was considered that the method of using the volume and the infiltration rate of greenhouses was reasonable for the infiltration loss. Floor heat flux measured in the center of the greenhouse tended to increase toward negative slightly according to the differences between indoor and outdoor temperature. By contrast, floor heat flux measured at the side of the greenhouse tended to increase greatly into plus according to the temperature differences. Based on the measured results, a new calculation method for ground heat exchange was developed by adopting the concept of heat loss through the perimeter of greenhouses. The developed method coincided closely with the experimental result. Average transmission heat loss was shown to be directly proportional to the differences between indoor and outdoor temperature, but the average overall heat transfer coefficient tended to decrease. Thus, in calculating the transmission heat loss, the overall heat transfer coefficient must be selected based on design conditions. The overall heat transfer coefficient of the experimental greenhouse averaged $2.73W{\cdot}m^{-2}{\cdot}C^{-1}$, which represents a 60% heat savings rate compared with plastic greenhouses with a single covering. The total heating load included, transmission heat loss of 84.7~95.4%, infiltration loss of 4.4~9.5%, and ground heat exchange of -0.2~+6.3%. The transmission heat loss accounted for larger proportions in groups with low differences between indoor and outdoor temperature, whereas infiltration heat loss played the larger role in groups with high temperature differences. Ground heat exchange could either heighten or lessen the heating load, depending on the difference between indoor and outdoor temperature. Therefore, the selection of a reference temperature difference is important. Since infiltration loss takes on greater importance than ground heat exchange, measures for lessening the infiltration loss are required to conserve energy.

• Fire Science and Engineering
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• v.18 no.1
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• pp.54-66
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• 2004

In this article, we are to suggest the hazard-assessing method for the underground pipelines, and find out the pipeline-maintenance schemes of high efficiency in cost. Three kinds of methods are applied in order to refer to the approaching methods of listing the hazards for the underground pipelines: the first is RBI(Risk Based Inspection), which firstly assess the effect of the neighboring population, the dimension, thickness of pipe, and working time. It enables us to estimate quantitatively the risk exposure. The second is the scoring system which is based on the environmental factors of the buried pipelines. Last we quantify the frequency of the releases using the present THOMAS' theory. In this work, as a result of assessing the hazard of it using SPC scheme, the hazard score related to how the gas pipelines erodes indicate the numbers from 30 to 70, which means that the assessing criteria define well the relative hazards of actual pipelines. Therefore. even if one pipeline region is relatively low score, it can have the high frequency of leakage due to its longer length. The acceptable limit of the release frequency of pipeline shows 2.50E-2 to 1.00E-l/yr, from which we must take the appropriate actions to have the consequence to be less than the acceptable region. The prediction of total frequency using regression analysis shows the limit operating time of pipeline is the range of 11 to 13 years, which is well consistent with that of the actual pipeline. Concludingly, the hazard-listing scheme suggested in this research will be very effectively applied to maintaining the underground pipelines.

• The Korean Nurse
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• v.36 no.5
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• pp.45-62
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• 1998

The study was conducted from November 1995 to May 1996 at the one general hospital in Seoul. The total subjects of this study were 412 patients who have the experience of fall accident, among them 31 was who have fallen during hospitalization and 381 was who visited emergency room and out patient clinic. The purposes of this study were to determine the characteristics, risk factors and results of fall accident and to suggest the nursing strategies for prevention of fall. Data were collected by reviewing the medical records and interviewing with the fallers and their family members. For data analysis, spss/pc+ program was utilized for descriptive statistics, adjusted standardized $X^2$-test. The results of this study were as follows: 1) Total subjects were 412 fallers, of which 245(59.5%) were men and 167(40.5%) were women. Age were 0-14 years 79(19.2%), 15-44 years 125(30.4%), 45-64 years 104(25.2%), over 65 years 104(25.2%). 2) There was significant association between age and the sexes ($X^2$=39.17, P=0.00). 3) There was significant association between age and history of falls ($X^2$=44.41. P= .00). And history of falls in the elderly was significantly associated with falls. 4) There was significant association with age and medical diagnosis ($X^2$=140.66, P= .00), chief medical diagnosis were hypertension(34), diabetis mellitus(22), arthritis(11), stroke(8), fracture(7), pulmonary tuberculosis(6), dementia(5) and cataract(5), 5) There was significant association between age and intrinsic factors: cognitive impairment, mobility impairment, insomnia, emotional problems, urinary difficulty, visual impairments, hearing impairments, use of drugs (sedatives , antihypertensive drugs, diuretics, antidepressants) (P < 0.05). But there was no significant association between age and dizziness ($X^2$=2.87, P=.41). 6) 15.3% of total fallers were drunken state when they were fallen. 7) Environmental factors of fall accident were unusual posture (50.9%), slips(35.2%), trips (9.5%) and collision(4.4%). 8) Most of falls occurred during the day time, peak frequencies of falls occurred from 1pm to 6pm and 7am to 12am. 9) The places of fall accident were roads(22.6%), house-stairs 06.7%), rooms, floors, kitchen (11.2%), the roof-top, veranda, windows(10.9%), hospital(7.5%), ice or snowy ways(5.8%), bathroom(4.9%), playground, park(4.9%), subway-stairs(4.4%) and public-bathrooms (2.2%). 10) Activities at the time of fall accident were walking(37.6%), turning around or reaching for something(20.9%), going up or down stairs09.2%), exereise, working07.4%), up or down from a bed(2.7%), using wheelchair or walking aids, standing up or down from a chair(2.2%) and standing still(2.2%). 11) Anatomical locations of injuries by falls were head, face, neck(31.3%), lower extremities (29.9%). upper extremities(20.6%), spine, thorax, abdomen or pelvic contents(l1.4%) and unspecified(2.9%). 12) Types of injures were fracture(47.6%), bruises03.8%), laceration (13.3%), sprains(9.0%), headache(6.6%), abrasions(2.9%), intracranial hemorrage(2.4%) and burns(0.5%). 13) 41.5% of the fallers were hospitalized and average of hospitalization was 22.3 days. 14) The six fallers(1.46%) died from fall injuries. The two fallers died from intracranial hemorrage and the four fallers died of secondary infection; pneumonia(2), sepsis(1) and cell lulitis(1). It is suggested that 1) Further study is needed with larger sample size to identify the fall risk factors. 2) After the fall accident, comprehensive nursing care and regular physical exercise should be emphasized for the elderly person. 3) Safety education and safety facilities of the public place and home is necessary for fall prevention.

• Journal of Korean Society of Forest Science
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• v.76 no.4
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• pp.397-409
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• 1987

This study was executed to analyze the user's impact on vegetation structure changes and user's psychology in Odongdo Island of Hallyo-Haesang National Park. Five sites were sampled for vegetation structure changes vi the study area according to the extent of impact observed. Also user's psychology was studied through questionnaire with the visitors and 366 answers were collected at random sampling in May, 1986. Evergreen broad-leaved forest, i.e. Machilus thunbergii, Cinnamomum camphora, and Camellia japonica forest, took possession of 32.5% (3.91ha) of total forest area when condisering the actual vegetation. Camellia japonica community covered 40.0% (4.72ha) and Sasa coreana community took possession of 41.8% (5.02ha). The area of environmental impact grade 3 and 4 area covered 44.3% of total forest area and it should be restored because self-repair seemed to be impossible. The evergreen broad-leaved forest was destoryed seriously with no younger trees in middle and lower layers by overuse impact and would be bared soon. So the preservation of autochthonous flora is required by the control of the number of users. It was shown that most of visitors come on holidays and Sunday and places which were favorably impressed were shown as the area of showing the sea and Camellia forest. Overall levels of satisfaction was comparatively low, consequently 55% of visitors were satisfied. This level of satisfaction was associated with number of users, landscape of forest and number of facilities.

• Journal of Wetlands Research
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• v.23 no.4
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• pp.352-363
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• 2021

The purpose of this study was to evaluate the load of nutrients contained in the drainage discharged from the facility horticultural complex and to use them for re-use of fluids and design for introduction of water treatment plants. Representative hydroponic cultivation crops were selected as tomato, paprika, cucumber, and strawberry, and the total number of samples analyzed for water quality was 80. As a result of the analysis, since various fertilizer components such as N, P, K⁺, Na⁺, Mg²⁺, Ca²⁺, Si₄⁺, HCO₃^-, Cl^-, S^2-, Fe, Mn, Cu, Zn, Mo and B are contained at very high concentrations in the drainage, the need for water treatment was confirmed. Through statistical analysis, it was analyzed that the drainage concentration of strawberries was lower than that of tomatoes, paprika, and cucumbers. In the case of tomatoes, these essential ion concentrations are the highest, so it was confirmed that they are subject to valuable resources in terms of reuse of fertilizers. The load of N and P of the drainage discharged from the facility horticultural complex 1m² was analyzed. For N, the daily processing capacity of 4.0 kg of tomatoes, 3.3 kg of paprika, 3.0 kg of cucumbers, and 1.5 kg of strawberries was calculated based on 1 ha. It was suggested that the P concentration needs a scale and capacity that can handle 0.5 kg of tomatoes, 0.6 kg of paprika, 0.4 kg of cucumber, and 0.2 kg of strawberries per day. Through this study, the amount of nitrogen and phosphorus contained in the drainage discharged from the greenhouse of each crop was evaluated to analyze the economy. In addition, it was expected to be used as basic data that can be used to calculate the treatment capacity to be reflected when introducing water treatment facilities in facility horticultural complexes for sustainable agriculture.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.6
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• pp.41-48
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• 2018

The aim of this study is to provide foundational knowledge of how to enhance the user satisfaction of urban parks. The study seeks to identify essential factors that influence user satisfaction and to provide better design strategies for future park design as well as the reorganization of existing ones. To measure user satisfaction, this study used factor analysis to extract essential factors - facility conditions, landscape and scenery, safety, and kindness - by using data from a survey conducted by the city of Seoul in 2017. We then used a regression analysis to infer causal relationships between the independent variables and the dependent variables (user satisfaction). The results revealed that the most significantly and positively related variable to user satisfaction in urban parks was safety (${\beta}=0.276$, p<.000), followed by landscape and scenery (${\beta}=0.230$, p<.000), facility conditions (${\beta}=0.215$, p<.000), and kindness (${\beta}=0.208$, p<.000). The results indicate that, for future urban park designs, planners and designers should prioritize the issues of safety by adopting crime prevention through environmental design (CPTED). In addition, planners and designers of future park designs should heavily weigh the selection and provision of relevant facilities for the intended use as well as well-arranged and well-managed plants and trees. Based on the results of IPA analysis, the most urgent improvement elements appeared to be the factor of kindness; however, the impact of kindness influencing user satisfaction was less important than that of safety and landscape and scenery in the urban park design processes. This study demonstrates that to maximize the user satisfaction of the urban park design processes and to provide more valuable spaces for users, it is necessary to secure park safety and to create well-composed landscape and scenery. Future research should provide more detailed and specified urban park design strategies corresponding with the importance of the factors identified in this study.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.6
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• pp.1-15
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• 2020

The purpose of this study is to propose a direction for designing and managing a smart park for realizing a smart green city and to present measures in the landscape field to foster related industries. The research process is as follows. First, the concept of a smart park was operationally defined through a literature review, and three principles to be considered in the process of creation and management were established. Second, in terms of the three principles, problems and implications for improvement were derived through an analysis of established cases of smart parks in new and pre-existing cities. Third, a pool of designs and management standards for each spatial component of a smart park was prepared through literature and case studies, and then further refined through brainstorming with experts in related fields. Fourth, measures were suggested to the government, local governments, and the landscape field to promote smart park creation and management. The main findings are as follows. First, the concept of a smart park is defined as "a park that contributes to securing the social, economic, and environmental sustainability of cities and local communities by supporting citizens' safe and pleasant use of parks and improving the management and operational efficiency by utilizing the digital, environment, and material technologies." Second, the three principles of smart parks are to improve the intrinsic value of parks, to improve the innovative functions of parks to solve urban problems, and to make the design, construction, and management process smart. Third, improvement implications were derived through the analysis of cases of smart parks creation in new and pre-existing cities. Fourth, the directions for smart park design and management were suggested in five aspects: green area, hydroponic facility area, road and plaza area, landscape facilities area, and park design method. Fifth, as for policy implications for revitalizing the construction and management of smart parks, the development of smart park policy business models by city growth stage, and park type, the promotion of pilot projects, the promotion of smart park projects in connection with the Korean New Deal policy, and smart park policies led by landscape experts were presented.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.33 no.12
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• pp.81-90
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• 2017

This study was conducted to investigate the thermal environment status of nursery rooms in workplace daycare centers in Jeju and propose measures to improve their indoor physical thermal environment. For this purpose, measurements were performed in the winter indoor physical environment of 51 nursery rooms in 11 workplace daycare centers and a psychological evaluation survey on the thermal environment of nursery rooms was conducted for 70 nursery teachers. The investigation was carried out over 11 days in January 2017. The results are as follow. The average indoor temperature of the nursery rooms was $21.3^{\circ}C$($18.7-23.8^{\circ}C$) and the indoor temperatures of 47 nursery rooms (92.9%) were higher than the environmental hygiene management standard for domestic school facilities ($18-20^{\circ}C$). The average relative humidity was 33.9% (16.4-56.0%), and 37 nursery rooms (86.3%) showed a lower average relative humidity than the standard (40-70%). The average absolute humidity was $9.1g/m^3$ ($4.7-13.6g/m^3$), which was lower than the standard for preventing influenza ($10g/m^3$). When the indoor temperature and humidity of the nursery rooms were compared with international standards, it was found that 85% or more of the 51 nursery rooms maintained appropriate indoor temperatures, but 40-50% of the nursery rooms maintained a low humidity condition. Therefore, they need to pay attention to maintaining the appropriate humidity of the nursery room to keep the children healthy. The average indoor temperature of the nursery rooms showed a weak negative correlation with the average relative humidity. The indoor temperature had a significant effect on the relative humidity: a higher indoor temperature resulted in lower relative humidity. Regarding the fluctuations in the average indoor temperature of the nursery rooms during the day, in daycare centers that used floor heating, the indoor temperature gradually increased form the morning to the afternoon and tended to decrease during lunch time and the morning and afternoon snack times, due to ventilation. The daycare centers that used both floor heating and ceiling-type air conditioners showed a higher indoor temperature and greater fluctuations in temperature compared to the daycare centers that used floor heating only. In the survey results, the average value of the whole body thermal sensation was 3.0 (neutral): 32 respondents (62.7%) answered, "Neutral", Which was the largest number, followed by 21 respondents (30%) who answered, "Slightly hot" and 17 respondents (24.2%) who answered, "Slightly cold." Twenty-nine respondents answered, "Slightly dry," which was the largest number, followed by 28 respondents (54.9%) who answered, "Neutral" and 10 respondents (19.6%) who answered, "Dry." The total number of respondents who answered, "Slightly dry" or "Dry" was large at 39 (56.4%), which suggests the need for indoor environment management to prevent a low-humidity environment. To summarize the above results about the thermal environment of nursery rooms, as the indoor temperature increased, the relative humidity decreased. This suggests the effect of room temperature on the indoor relative humidity; however, frequent ventilations also greatly decrease the relative humidity. Therefore, the ventilation method and the usage of air conditioning systems need to be re-examined.