• Journal of Korean Society of Steel Construction
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• v.25 no.3
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• pp.289-297
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• 2013

In this study, the local buckling behavior of steel built-up columns, fabricated with grade 800MPa high performance (HSA800), was investigated to verify the suitability of width-to-thickness ratio limits adopted by the current design code. For this purpose, an experimental program was designed and performed for HSA800 steel column specimens with various width-to-thickness ratios. Then the experimental results were compared and verified with finite element analysis results. The parametric analytical studies with various width-to-thickness ratios were also performed to investigate the missing data from the limited experimental studies. From the experimental and analytical studies, It was found that the finite analysis models could reasonably estimate the test results within the 5.3% average differences. The local buckling behaviors of HSA800 steel columns were found to be largely depend on the values of initial imperfection introduced into finite element analyses.

• The Journal of the Korea Contents Association
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• v.17 no.10
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• pp.406-419
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• 2017

This study is to explore the essence and meaning of part-time job experience, in particular, to deduce growth experience through part-time jobs. This study is based on time-experience of phenomenological research method developed by the van Manen. For this research, the research data was collected by reviewing high school student part timer in Gyeonggi-do, those who had experience of average of two-year part time work or currently at work, and by undertaking in-depth interviews with seven of them from the March to April of 2017 with the agreements of the participants of this study. Time-experiences, i.e. part-time job experiences of youths, can be arranged as the following subjects. 'the feeling necessity part-time job and seeking it', 'adapting hard life of part-time', growth-experiencing through part-time work..The necessities for part-time job are feeling up consumption needs, aidsing domestic economy, pursuing independence, social and leisure life, self growth and preparing for the future. Adapting of part-time jobs are mastering, enduring, skillfuling work related to work adatation, and enduring ostracizing of old members, stopping and lasting, building bonds related to relationship adaptation. Growth-experiencing through part-time work are formig rational management for money, mental growth, preparing for the future. Based on these findings, the suggestion and limitation of the study were presented.

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.146-151
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• 2010

In order to improve T-N and T-P removal in HF (horizontal flow)-HF hybrid constructed wetlands by natural purification method for treating the hydroponic wastewater in greenhouses, the efficiency of water treatment as affected by the injection method of hydroponic wastewater, the addition of special filter media, the particle size of filter media, and the injection ratio of hydroponic wastewater in $1^{st}$ HF and $2^{nd}$ HF beds were investigated in small-scale HF-HF hydroponic wastewater treatment apparatus. Removal rate of T-P in the water in HF-HF hydroponic wastewater treatment apparatus with calcite as affected by addition method of special filter media was higher than that in HF-HF hydroponic wastewater treatment apparatus with other filter media. Removal rate of BOD, COD, SS, T-N and T-P in the water in mixed filter media with calcite were 86, 84, 87, 50 and 97%, respectively. Removals of pollutants except for T-P in the water were slightly different. Therefore, it should be considered that the removal rate of T-P was good for calcite in HF-HF hydroponic wastewater treatment apparatus. To improve T-N and T-P removal, the optimum particle size of filter media was 1.2 mm, and the optimum injection ratio ($1^{st}$ HF bed : $2^{nd}$ HF bed) of hydroponic wastewater was 60:40.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.13 no.1
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• pp.57-68
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• 2010

The purpose of this study is to analyze the characteristics of environment-friendliness of waterproof materials based on comprehensive experiments on waterproofness in terms of coefficients of permeability, harmfulness of waterproof materials and fish toxicity of Oryzias latipes mortality to verify eco-toxicity of each method of construction and waterproof material, which are to be applied by taking eco-toxicity into account when building ecological flows in upper areas on natural and artificial grounds. As a result, the following conclusions have been reached in this study: 1. In regard of the harmfulness analyzed, each material showed a different result of analytical value in each lab tank. Compared to input water, pH, COD, SS, T-P, and T-N values increased a little, but DO value decreased. The value of turbidity analyzed independent of the water quality standard of aquatic ecosystem set forth by the Ministry of Environment increased a little compared to the value in input water. 2. In the experiment of fish toxicity, compacted quicklime, cement fluid waterproof material, cement mortar waterproof material and bentonite powder were found to have 100% of fish mortality, respectively, and membrane waterproof material showed 83.3% of mortality, indicating strong fish toxicity. Improved asphalt sheet (63.3%) and synthetic rubber sheet (53.3%) were analyzed to have medium fish toxicity, while bentonite sheet (6.7%), Hwang-toh (6.7%) and clay (3.3%) showed relatively lower mortality and fish toxicity. 3. Regarding the analysis on waterproofness in terms of the coefficient of permeability of each waterproof material, improved asphalt sheet, synthetic rubber sheet, membrane waterproof material, cement fluid and mortar waterproof material and bentonite sheet were found impervious in case no leakage takes place in construction. Bentonite powder was found practically impervious based on the analytical results from the experiment done in compliance with weight ratios. So were the clay and Hwang-toh from the experimental results. To sum up such results as found in the experiment mentioned so far, the values of harmfulness and waterproofness analyzed were different in each lab tank, but there was absolutely little correlation with the mortality gained from the experiment on fish toxicity. In the experiment of fish toxicity, environment-friendly waterproof materials were analyzed, and it was found that clay, Hwang-toh and bentonite sheet are highly environment-friendly. In contrast, synthetic rubber and improved asphalt sheets were found to have medium-level environment-friendliness. Also, membrane water-proof materials, compacted quicklime, cement fluid and mortar waterproof material and bentonite powder were analyzed to have low environment-friendliness.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.6
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• pp.1-19
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• 2017

This study set out to identify problems with amphibian habitation by the wetland types and improve their habitation environment in urban forest wetlands, thus creating a habitat for amphibians. Study site include forest swamps in Jatjul Park as well as Yeoji neighborhood Park in Guro-gu, and in Choansan neighborhood Park in Dobong-gu. The forest swamp in Jatjul Park gets its water from Mt. Maebong and it is a former escalated farmland-turned wetland. The swamp area is $2,500m^2$, a forest zone and a landscape planting site are 83.27% and 6.70% each. Target species Seoul pond frogs are inseparable from rice fields because they live in a short radius of and lay eggs in or near paddy fields, and Rana nigromaculata have similarities with Rana plancyi chosenica in choosing their habitats. There was need for paths that would lead to other paths so amphibians would spread to other parts of the forest and for measures to secure open water. Modifying a variety of routes for water, human and animals along with building a buffer to keep the core habitation zones were required. The forest swamp in Yeonji neighborhood Park used to be a water reservoir on the foot of Mt. Gunji. The swamp area is $1,980m^2$, a forest zone and farmland account for 80.61% and 4.88% each. Non-point pollutants from upstream along run into the subject forest marsh, bare ground on the around swamp and steep stone embankments obstructed amphibians. Target species was Bufo gargarizans that live in forests and edges of hills and spawn in deep water. The forest swamp in Choansan neighborhood Park gets its water from Mt. Choan and it is close to its water source that it is a mountain stream forest wetland. The basin and the swamp are $35,240m^2$ and $250m^2$ in size respectively. A forest zone accounts for 90.20%, high stone embankments laid in refurbishing the valley obstruct amphibians and there is water shortage in times of droughts. Target species were Rana coreana, Rana dybowskii and Hynobius leechii that live in mountain valleys, streams and wetlands and lay eggs in forest marshes and rocks in valleys. Looking into the three swamps of amphibian habitation, I came to conclusions that those wetlands were suitable for their amphibians but man-made facilities blocked their corridors leading to other corridors and even killed off target species in some parts of those swamps by destroying those parts. Amphibians live in water, on ground and underground at different stages of life. Hence, we should take this fact into consideration when planning their habitats and design core habitation zones, buffers zone and use zones accordingly. Buffer zones ought to be between core habitation zones and surrounding trees. Aiming at protecting core habitation zones, buffers should be in harmony with habitation zones. Use zones should be minimized in size and not in direct contact with core habitation zones.

• Journal of Hospice and Palliative Care
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• v.4 no.2
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• pp.154-160
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• 2001

Purpose : This study, as the first year project of setting up a community based management system, was attempted for the cancer patients and their family to improve their quality of life; investigating and managing the cancer patients, educating volunteers and connecting the patients with the volunteers were performed. Method and result : The education of managing cancer patients for the volunteers was done once in lune for 2 days to the 80 volunteers. Questions about education effect, volunteer motivation and so on were made up. The survey showed, generally, education satisfaction level was high and a longer education and an intensive course were needed and was suggested that organizing a volunteer community be needed for the continuous further education and systematic management. As the result, after the public health center and volunteers deliberated, a volunteer community consisting of 4 teams, 28 members was organized, launched in Oct. and operated for the cancer patients and their family. For investigating and enrolling the patients, advertising on a local information paper, recommending of local doctors, publicizing by educating the heads of a subdivision of the city, the heads of a neighborhood association and the people in charge of the related local communities such as women's society, and surveying the community by volunteers were performed and the total, 41 patients were registered. Management of cancer patients was carried out by volunteers in a community and in a nursing school. A regional volunteers' community is composed of 23 members and they have worked 87 times, that is 3.8 times per capita on an average. The content of duties is attending the education (41.1%) the most. A volunteers' community of nursing students composed of 12 members have worked 135 times, that is 11.3 times per capita on an average. The content of duties - consulting with patients and home visiting (37.8 %) were the most and survey for investigating the cancer patients was the second. Conclusion : This study has the meaning that this is the guiding attempt in building a community based management system, and especially the achievement of this study is that a regional society organized a volunteer community for the cancer patients by itself and went into action for the cancer patients and their family. Furthermore, to activate this volunteering, it is necessary to keep managing volunteers and running continuing education or the intensive course of the volunteers. Indeed we should let the patients have good impression on this program through publicity and education for the residents to keep track of more cancer patients. For that, systematic and powerful cooperation of a self-administrative organization is required.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.811-823
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• 2019

Slip form method is applied to many cases of a shaft these days because it is safer, more economical and faster than cast-in-place method. Slip-up height of the method is approximately 2.5 to 4.0 m/day. If the temperature of concrete is outside the range of 10 to 30℃, the effects of changes in strength or elastic characteristics are significant. Therefore, it is difficult for slip-up speed to be higher than 3 m/day during winter construction. In addition, concrete has heat caused by hydration, which causes temperature cracking of hardened concrete. Therefore, temperature control of concrete curing is necessary for the continuous slip-up of slip form. In this study, the rebound hardness, time of ultrasonic waves propagation, heat of hydration, and external temperature are measured by developing heating panels and test devices for the continuous slip-up. Based on this, heating slip form is manufactured; this was applied to "Kimpo sites" and "Sinwol sites". The compared slip-up speed samples were 1.9 m/day or 0.200 m/hr on average at Gimpo sites (08:00~17:30) and 2.0 m/day or 0.210 m/hr at Sinwol sites.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.2
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• pp.105-116
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• 2018

This study started by examining 24 newly-built elementary schools in Sejong City with regard to their present conditions of in-between space. After categorizing the space according to its spatial composition, 5 schools were selected and analyzed in relation to the current status and frequency of use of their in-between space. Among the (other schools, the analysis gave the following results: 1) There was much higher usage of the in-between space for rest/play than for learning, which suggested that more rest/play area and apparatus should be provided. 2) Piloti areas were preferred, and a greater number of activities took place in these places than in the adjoining open areas. 3) When the in-between space was combined with a passage (as in the case of E2 and E3), a separation must be provided in order not to interfere with the rest/play activities. 4) In planning the in-between space, priority should be given to activities over landscape purposes. 5) Diverse and easy access to the space must be planned, particularly as the main entrance is not directly connected to the space. Entry at the end of an adjacent building could be a possible solution.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.6
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• pp.674-680
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• 2013

As the range of marine leisure activity gradually expands to ocean-going, a habitable cruise boat has been getting the limelight. Advanced countries in the marine leisure industry in Europe and North America have already secured their competitiveness in designing and building cruise boats by elegant design, ergonomic structure and fuel efficiency through the adoption of light-weight hull materials. In contrast, mostly small power boats are developed and built in Korea, and GFRP take up the most of hull materials. This study inquired into the design and characteristics of a 50ft-class CFRP that ocean-going is possible. The hull-form of the CFRP cruise boast were analyzed to propose a hull form for the designed ship (MMU-C.B), and based on that, the design model of the MMU-C.B was built. Finally, the MMU-C.B's characteristics of the resistance performance and hull-planing were found by comparative reviews with the results of model tests of GFRP pleasure yachts.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.12
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• pp.7725-7730
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• 2013

Objective: The purpose of this study was to evaluate secondhand smoke (SHS) exposure inside selected public places to provide basic data for the development and promotion of smoke-free policies. Methods: Between March and May 2009, an SHS exposure survey was conducted. $PM_{2.5}$ levels and air nicotine concentrations were measured in hospitals (n=5), government buildings (4), restaurants (10) and entertainment venues (10) in Seoul, Republic of Korea, using a common protocol. Field researchers completed an observational questionnaire to document evidence of active smoking (the smell of cigarette smoke, presence of cigarette butts and witnessing people smoking) and administered a questionnaire regarding building characteristics and smoking policy. Results: Indoor $PM_{2.5}$ levels and air nicotine concentrations were relatively higher in monitoring sites where smoking is not prohibited by law. Entertainment venues had the highest values of $PM_{2.5}$(${\mu}g/m^3$) and air nicotine concentration(${\mu}g/m^3$), which were 7.6 and 67.9 fold higher than those of hospitals, respectively, where the values were the lowest. When evidence of active smoking was present, the mean $PM_{2.5}$ level was 104.9 ${\mu}g/m^3$, i.e., more than 4-fold the level determined by the World Health Organization for 24-hr exposure (25 ${\mu}g/m^3$). Mean indoor air nicotine concentration at monitoring sites with evidence of active smoking was 59-fold higher than at sites without this evidence (2.94 ${\mu}g/m^3$ vs. 0.05 ${\mu}g/m^3$). The results were similar at all specific monitoring sites except restaurants, where mean indoor $PM_{2.5}$ levels did not differ at sites with and without active smoking evidence and indoor air nicotine concentrations were higher in sites without evidence of smoking. Conclusion: Nicotine was detected in most of our monitoring sites, including those where smoking is prohibited by law, such as hospitals, demonstrating that enforcement and compliance with current smoke-free policies in Korea is not adequate to protect against SHS exposure.