• Journal of the Korean Applied Science and Technology
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• v.39 no.2
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• pp.368-376
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• 2022

Spontaneous ignition occurs in industrial sites or anywhere in our lives, and is a phenomenon in which a substance ignites itself without an ignition source in the atmosphere. As the rate of chemical reaction increases, the heat generated increases, and the risk of spontaneous ignition increases. In this study, safe raw materials used for food and cosmetics were mixed to prepare coal spontaneous ignition prevention agents specifically among various spontaneous ignition phenomena. The effect of suppressing spontaneous combustion of coal was confirmed through lab and field tests with low-calorie, low-grade coal from Indonesia. As a result of the outdoor field test, the ignition prevention agent manufactured in this study compared with the control group(Fire after 90 days) showed excellent ignition inhibitors for more than 120 days. In addition, CO concentration control was confirmed by comparing the concentration of carbon monoxide for 50 days at the indoor coal yard. It was confirmed that the results were better than the comparative group coal and the existing anti-firing method. In addition, the possibility of coal fire prevention agents for indoor coal farms will be applied from 2024 was confirmed by studying the environment and safety of workers' working environments through official test such as soil and water quality test, MSDS of coal fire prevention agents in consideration of working workers, water quality, and eye irritation tests.

• Journal of Korean Society of Rural Planning
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• v.18 no.2
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• pp.57-68
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• 2012

This study is to suggest the improving methods for rural community centers by analysis of 30 community centers in Samnangjin-eup, Miryang city, Gyeongnam. To fulfill this purpose, the facilities, usable condition and management system were examined. The user needs and level of satisfaction were also investigated through the interviews with 858 citizens. The average size of the centers is $96m^2$, and 73% of them are one-story buildings. Women use the community center more frequently than men in ratio of 6:4. 43.4% of interviewees visit the center 1 or 2 times a month, but on the other hand 27.4% of them use the center almost every day. Recess is surely the main purpose, and health care and community meeting are next two reasons. 67.8% and 72.4% of them are not satisfied with the inside and outside of the community center respectively. The interview results demonstrate that the most important issue is the lack of facilities. To improve the community centers in Samnangjin-eup, first of all, various kinds of indoor and outdoor facilities must be equipped. Secondly, considering the center is the core of rural community life, the qualitative improvement in accommodation is also needed as well as facility diversification. The efficiency of space utilization is another issue. A small piece of land or abandoned space must be utilized. Moreover, it is very critical that the users are mostly seniors and elders, so improvements of facilities will be executed in terms of safety and convenience. Finally, administrative and financial support should be made for the people, so as to maintain the the rural community center on their own.

• Journal of Environmental Science International
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• v.25 no.8
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• pp.1107-1114
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• 2016

This research, sponsored by the Korean Ministry of Environment in 2014, was the first epidemiological study in Korea that investigated the health impact assessment of radon exposure. Its purpose was to construct a model that calculated the annual mean cumulative radon exposure concentrations, so that reliable conclusions could be drawn from environment-control group research. Radon causes chronic lung cancer. Therefore, the long-term measurement of radon exposure concentration, over one year, is needed in order to develop a health impact assessment for radon. Hence, based on the seasonal correction model suggested by Pinel et al.(1995), a predictive model of annual mean radon concentration was developed using the year-long seasonal measurement data from the National Institute of Environmental Research, the Korea Institute of Nuclear Safety, the Hanyang University Outdoor Radon Concentration Observatory, and the results from a 3-month (one season) survey, which is the official test method for radon measurement designated by the Korean Ministry of Environment. In addition, a model for evaluating the effective annual dose for radon was developed, using dosimetric methods. The model took into account the predictive model for annual mean radon concentrations and the activity characteristics of the residents.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.11
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• pp.1706-1712
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• 2022

Recently, the safety of chemical substances has gained attention due to incidents occurring in petrochemical industrial complexes, such as gas leaks and fires. In particular, industrial complexes in Ulsan and Yeosu (South Korea) are valuable as they significantly contribute to the petrochemical industry, but accidents may occur due to chemical leakage. Therefore, in this study, sensor nodes are configured at an interval of 20 [m] based on outdoor facilities standards to respond to chemical accidents, and exposure consideration of 8 h (TWA) and 15 min (STEL) are proposed in TLVs. The proposed system pre-processes data collected in multi-hop communication at a cycle of 0.6-0.75 [s] using Python and stores it in the MySQL database through SQL and a real-time remote monitoring system that updates the stored data once every 5 s is implemented by linking MySQL and Grafana.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.99-106
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• 2006

Chlorothalonil and imidacloprid sprayed onto the green peppers were degraded more faster at outdoor than in greenhouse. These results were affected by dew and photodegration, considering no rain during the experimental period. Chlorothalonil, esfenvalerate and imidacloprid in green pepper, green twist pepper and sweet pepper did not show any residual pattern, because green peppers are one of the continuous harvesting crops and pesticides could not be sprayed homogeneously on them. When green peppers were pickled with soy sauce and green twist peppers were fried with vegetable oil, the amounts of pesticides such as alpha-cypermethrin, bifenthrin, chlorfenapyr, esfenvalerate and imidacloprid were diminished to the levels of about $30{\sim}71$ and $20{\sim}41%$, respectively. Esfenvalerate and imidacloprid could not be detected in 2 month-old hot pepper paste. The removal rates of pesticide residues in leaves of green peppers were about $22{\sim}37%$ by washing, about $74{\sim}95%$ by parboiling, and about $17{\sim}55%$ by drying after parboiling.

• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.41-51
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• 2019

With the aging of the population and the slowdown of the job market, elderly workers make up a large portion of the construction workforce. Also, due to the nature of the construction industry, where outdoor work is frequent, the weather has a more sensitive impact on elderly workers than on younger ones. The study aims to analyze the degree of weather risks exposed to elderly workers in the construction industry using the measure of work loss days. To that end, construction accidents that affected 28,514 elderly workers in seven cities from 2012 to 2016 (a total of 12,789 days) were analyzed to calculate work loss days per different weather factors. The results show that the elderly workers were seriously affected when the temperature was between $-12^{\circ}C$ and $-10^{\circ}C$, humidity between 55% and 60%, precipitation between 128mm and 181mm, and wind speed between 5.5m/s and 6.5m/s, with the highest work loss days. The combined effects between the weather factors were also analyzed to identify the conditiosn that leaded to high work loss days of elderly workers. This study contributes to effective safety management and pleasant working environment between weather factors and shedding light on the relationship between weather factors and work loss days of elderly workers.

• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.39-44
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• 2009

This study was conducted to evaluate the actual risk of fipronil on worker honey bees (Apis mellifera L.) through acute contact toxicity test, acute oral toxicity test, toxicity of residues on foliage test, and small scale field test. The $48h-LD_{50s}$ of fipronil SC on honeybee were $0.005{\mu}g$ a.i./bee in acute contact toxicity test and $0.004{\mu}g$ a.i./bee in acute oral toxicity test, respectively. In toxicity of residues on foliage test, fipronil showed over 90% of mortality during 28days after treatment at recommended application rate. The $DT_{50}$ of dislodgeable foliar residue was 9 days. Finally, In small scale field test, fipronil showed similar toxicity in the residues on foliage test. It was concluded that fipronil has very high acute toxicity and long residual toxicity to honeybee. Therefore, fipronil is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area. To protect honeybee and wild pollinators from outdoor use of fipronil, ultimately it should need to limit for only indoor use to prevent pollinators from unintentionally exposure of fipronil.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.6 no.1
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• pp.67-76
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• 1996

This study was performed to estimate total dust concentrations and particle size distribution of wood dust in the furniture and sawmill industries. To compare total wood dust concentrations, two samplers recommended by the American Conference of Governmental Industrial Hygienists and by the National Institute for Occupational Safety and Health were used. Concentration data were analyzed by paired-t tests using the SAS program and two parameters of the particle size distributions were determined by histogram. The results were as follows: 1. Particle size distributions showed a unimodal pattern in cutting and a bimodal in sanding operations. Mass median aerodynamic diameters(MMAD) were $17.35{\mu}m$ in cutting, and $1.39{\mu}m$ for small mode and $18.89{\mu}m$ for large mode in sanding operations. The proportions of particle size larger than $9.8{\mu}m$ estimated by the impactor were 61.16 % in cutting and 62.33 % in sanding operations, respectively. 2. The average personal total dust concentrations measured by IPM sampler were $17.12mg/m^3$ (GSD=1.45) from indoor samples, $2.97mg/m^3$(GSD=1.90) from outdoor samples in cutting, and $8.01mg/m^3$(GSD=1.58) from sanding operation. And those of by 37 mm closed-face cassette were $9.12mg/m^3$(GSD=1.46), $1.06mg/m^3$(GSD=1.99) from cutting, and $3.32mg/m^3$(GSD=2.16) from sanding operations. 3. The average area total dust concentrations measured by IPM sampler were $1.88mg/m^3$(GSD=2.04) from indoor cutting, $4.76mg/m^3$(GSD=2.83) from indoor sanding operations. And those of by 37mm closed-face cassette were $0.49mg/m^3$(GSD=2.34) from cutting, and $1.32mg/m^3$(GSD=3.03) from sanding operations. 4. The ratio of personal total dust concentrations measured by 37 mm closed-face cassette to those by IPM sampler were 35.7 %, 53.3 % from cutting, and 41.4 % from sanding operations. 5. The ratio of area total dust concentrations measured by 37 mm closed-face cassette to those by IPM sampler were 26.1 % from cutting, and 27.7 % from sanding operations. 6. A statistically significant difference of total dust concentrations between the 37 mm closed-face cassette and the IPM sampler was found.

• Journal of the Korea Society of Computer and Information
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• v.27 no.7
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• pp.49-55
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• 2022

In this paper, we propose an obstacle detection method that can operate robustly even in external environmental factors such as weather. In particular, we propose an obstacle detection system that can accurately inform dangerous situations in AR through DB-based feature matching and RANSAC-based multiplane method. Since the approach to detecting obstacles based on images obtained by RGB cameras relies on images, the feature detection according to lighting is inaccurate, and it becomes difficult to detect obstacles because they are affected by lighting, natural light, or weather. In addition, it causes a large error in detecting obstacles on a number of planes generated due to complex terrain. To alleviate this problem, this paper efficiently and accurately detects obstacles regardless of lighting through DB-based feature matching. In addition, a criterion for classifying feature points is newly calculated by normalizing multiple planes to a single plane through RANSAC. As a result, the proposed method can efficiently detect obstacles regardless of lighting, natural light, and weather, and it is expected that it can be used to secure user safety because it can reliably detect surfaces in high and low or other terrains. In the proposed method, most of the experimental results on mobile devices reliably recognized indoor/outdoor obstacles.

• Journal of Intelligence and Information Systems
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• v.25 no.3
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• pp.117-140
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• 2019

As the aging phenomenon accelerates and various social problems related to the elderly of the vulnerable are raised, the need for effective elderly care solutions to protect the health and safety of the elderly generation is growing. Recently, more and more people are using Smart Toys equipped with ICT technology for care for elderly. In particular, log data collected through smart toys is highly valuable to be used as a quantitative and objective indicator in areas such as policy-making and service planning. However, research related to smart toys is limited, such as the development of smart toys and the validation of smart toy effectiveness. In other words, there is a dearth of research to derive insights based on log data collected through smart toys and to use them for decision making. This study will analyze log data collected from smart toy and derive effective insights to improve the quality of life for elderly users. Specifically, the user profiling-based analysis and elicitation of a change in quality of life mechanism based on behavior were performed. First, in the user profiling analysis, two important dimensions of classifying the type of elderly group from five factors of elderly user's living management were derived: 'Routine Activities' and 'Work-out Activities'. Based on the dimensions derived, a hierarchical cluster analysis and K-Means clustering were performed to classify the entire elderly user into three groups. Through a profiling analysis, the demographic characteristics of each group of elderlies and the behavior of using smart toy were identified. Second, stepwise regression was performed in eliciting the mechanism of change in quality of life. The effects of interaction, content usage, and indoor activity have been identified on the improvement of depression and lifestyle for the elderly. In addition, it identified the role of user performance evaluation and satisfaction with smart toy as a parameter that mediated the relationship between usage behavior and quality of life change. Specific mechanisms are as follows. First, the interaction between smart toy and elderly was found to have an effect of improving the depression by mediating attitudes to smart toy. The 'Satisfaction toward Smart Toy,' a variable that affects the improvement of the elderly's depression, changes how users evaluate smart toy performance. At this time, it has been identified that it is the interaction with smart toy that has a positive effect on smart toy These results can be interpreted as an elderly with a desire to meet emotional stability interact actively with smart toy, and a positive assessment of smart toy, greatly appreciating the effectiveness of smart toy. Second, the content usage has been confirmed to have a direct effect on improving lifestyle without going through other variables. Elderly who use a lot of the content provided by smart toy have improved their lifestyle. However, this effect has occurred regardless of the attitude the user has toward smart toy. Third, log data show that a high degree of indoor activity improves both the lifestyle and depression of the elderly. The more indoor activity, the better the lifestyle of the elderly, and these effects occur regardless of the user's attitude toward smart toy. In addition, elderly with a high degree of indoor activity are satisfied with smart toys, which cause improvement in the elderly's depression. However, it can be interpreted that elderly who prefer outdoor activities than indoor activities, or those who are less active due to health problems, are hard to satisfied with smart toys, and are not able to get the effects of improving depression. In summary, based on the activities of the elderly, three groups of elderly were identified and the important characteristics of each type were identified. In addition, this study sought to identify the mechanism by which the behavior of the elderly on smart toy affects the lives of the actual elderly, and to derive user needs and insights.