• The Journal of Engineering Geology
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• v.26 no.2
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• pp.251-260
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• 2016

Groundwater flow due to hydraulic gradients across a geologic barrier surrounding a dam reservoir can cause swamps or wetlands to form on the downstream side of the dam, thereby restricting land use. The difference in head between the reservoir level and the downstream groundwater level creates a hydraulic gradient, allowing water to flow through the geologic barrier. We constructed a drainage system at the Daecheong dam to study the effects on groundwater levels and soil moisture contents. The drainage system consisted of a buried screened pipe spanning a depth of 1-1.5 m below a land surface. Groundwater levels were monitored at several monitoring wells before and after the drainage system was installed. Most well sites recorded a decline in groundwater level on the order of 1 m. The high-elevated site (monitoring well W1) close to the reservoir showed a significant decline in groundwater level of more than 2 m, likely due to rapid discharge by the drainage system. Soil moisture contents were also analyzed and found to have decreased after the installation of the drainage system, even considering standard deviations in the soil moisture contents. We conclude that the drainage system effectively lowered groundwater levels on the downstream side of the dam. Furthermore, we emphasize that water seepage analyses are critical to embankment dam design and construction, especially in areas where downstream land use is of interest.

• Journal of Gifted/Talented Education
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• v.20 no.1
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• pp.289-316
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• 2010

The purpose of this study was to investigate the relationship between thinking style and learning style of gifted children in elementary school. The subjects were 178 fourth, fifth and sixth grade elementary school students who enrolled in gifted education program. They were given the Thinking Style Questionnaire and the Grasha Reichmann Student Learning Style Questionnaire. Descriptive statistics, correlation analysis and canonical correlation analysis were performed. Results indicated that gifted students prefer legislative, judical, liberal, local, hierarchic, external thinking styles known to be related to creative and critical thinking rather than executive and conventional styles. Meanwhile, in the aspect of learning style, independent learning style than the dependent learning style, competitive style than the collaborative style, and participatory style than the avoiding style were significantly scored higher. The canonical analysis showed that thinking styles and learning styles share 59%(Rc=.77) each other, indicating the two variables had significant close relationship. External, liberal, hierarchic, judical, executive, and liberal thinking styles in the order named showed higher cross loading in the independent variable set, likewise independent, participatory, collaborative, and competitive learning styles in the dependant variable set. The results indicate that the external, liberal, hierarchic, judical, executive, and liberal thinking styles can be the significant predictors of independent, participatory, collaborative, and competitive learning styles. The implications of the study related to the gifted education were discussed in depth.

• Atmosphere
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• v.26 no.2
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• pp.257-275
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• 2016

Asian dust is a seasonal meteorological phenomenon influencing most East Asia, irregularly occurring during spring. Unusual heavy Asian dust event in winter was observed in Seoul, Korea, with up to $1,044{\mu}g\;m^{-3}$ of hourly mean $PM_{10}$, in 22~23 February 2015. Causes of such infrequent event has been studied using both ground based and spaceborne observations, as well as numerical simulations including ECMWF ERA Interim reanalysis, NOAA HYSPLIT backward trajectory analysis, and ADAM2-Haze simulation. Analysis showed that southern Mongolia and northern China, one of the areas for dust origins, had been warm and dry condition, i.e. no snow depth, soil temperature of ${\sim}0^{\circ}C$, and cumulative rainfall of 1 mm in February, along with strong surface winds higher than critical wind speed of $6{\sim}7.5m\;s^{-1}$ during 20~21 February. While Jurihe, China, ($42^{\circ}23^{\prime}56^{{\prime}{\prime}}N$, $112^{\circ}53^{\prime}58^{{\prime}{\prime}}E$) experienced $9,308{\mu}g\;m^{-3}$ of hourly mean surface $PM_{10}$ during the period, the Asian dust had affected the Korean Peninsula within 24 hours traveling through strong north-westerly wind at ~2 km altitude. KMA issued Asian dust alert from 1100 KST on 22nd to 2200 KST on 23rd since above $400{\mu}g\;m^{-3}$ of hourly mean surface $PM_{10}$. It is also important to note that, previously to arrival of the Asian dust, the Korean Peninsula was affected by anthropogenic air pollutants ($NO_3^-$, $SO_4^{2-}$, and $NH_4^+$) originated from the megacities and large industrial areas in northeast China. In addition, this study suggests using various data sets from modeling and observations as well as improving predictability of the ADAM2-Haze model itself, in order to more accurately predict the occurrence and impacts of the Asian dust over the Korean peninsula.

• Geotechnical Engineering
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• v.10 no.2
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• pp.25-40
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• 1994

In order to investigate behavior of lateral flow by plasticity of soils and construction control due to it, in the case of unsymmetrical surcharge load on the soft soils, we examine the existing theoretical background, and compared and analysed the experimental results by model test. After model test fabricated by model test apparatus, which made full remolding samples of soft soils, we observed the state of behavior for deformation with increasing load step to constant time interval. The critical surcharge and ultimate capacity showed tendency to approach to the proposed value of Jaky and Meyerhof, and the lateral flow pressure of which the maximum value was acted on the depth calculated by z/H=0.26+1.71cu and one third value of the maximum lateral flow pressure acted on the ground surface, approach the trapezoid distribution And maximum lateral flow pressure will be calculated by proposed equation of Hong or simple equation which($\alpha=0.4$) the flow pressure coefficient . of proposed equation by Tschebotarioff exchanged to($\alpha=K_0$) . Basides, the failure surcharge by [(q/$y_m$)-q] and [$S_y-(y_m/S_y)$] showed the smaller than ultimate bearing capacity, especially failure criteria line of control diagram of [$S_y(y_m/S_y)$] will be calculated by following equation. $S_y.=3.15exp[-0.58(y_m/S_y)$

• Journal of Periodontal and Implant Science
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• v.41 no.4
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• pp.176-184
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• 2011

Purpose: The final goal of regenerative periodontal therapy is to restore the structure and function of the periodontium destroyed or lost due to periodontitis. However, the role of periosteum in periodontal regeneration was relatively neglected while bone repair in the skeleton occurs as a result of a significant contribution from the periosteum. The aim of this study is to understand the histological characteristics of periosteum and compare the native periosteum with the repaired periosteum after elevating flap or after surgical intervention with flap elevation. Methods: Buccal and lingual mucoperiosteal flaps were reflected to surgically create critical-size, "box-type" (4 mm width, 5 mm depth), one-wall, intrabony defects at the distal aspect of the 2nd and the mesial aspect of the 4th mandibular premolars in the right and left jaw quadrants. Animals were sacrificed after 24 weeks. Results: The results from this study are as follows: 1) thickness of periosteum showed difference as follows (P<0.05): control group ($0.45{\pm}0.22$ mm)> flap-elevation group ($0.36{\pm}0.07$ mm)> defect formation group ($0.26{\pm}0.03$ mm), 2) thickness of gingival tissue showed difference as follows (P<0.05): defect formation group ($3.15{\pm}0.40$ mm)> flap-elevation group ($2.02{\pm}0.25$ mm) > control group ($1.88{\pm}0.27$ mm), 3) higher cellular activity was observed in defect formation group and flap-elevation groups than control group, 4) the number of blood vessles was higher in defect formation group than control group. Conclusions: In conclusion, prolonged operation with increased surgical trauma seems to decrease the thickness of repaired periosteum and increase the thickness of gingiva. More blood vessles and high cellular activity were observed in defect formation group.

• Korean journal of communication and information
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• v.66
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• pp.87-109
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• 2014

The purpose of this study is to investigate public art in Mullae art Village based on Adorno's Mimesis and explore a wide range of possibilities of new genre of public art. This study found out the new possibility of not only artist network, but also networks of local villagers and iron factory workers, and considered in-depth analysis of new genre public art in Mullae art village focusing on their active participations in art programs. By analyzing the artists' stories through interviews, low-cost rental accommodation brought a influx of artists into the village, and they formed their artist networks working by themselves. At this point, this could be judged a critical phenomenon in accordance with Adorno's mimesis. However, by external pressures such as government policies for setting up Mullae Art factory or downtown redevelopment, artists sought independent role in Mullae-dong and doing active public art programs grounded on mimesis. Artists were seeking a way to cope with the economy mechanism doing new genre of public art based on mimesis, and found out the possibility of formation of relationships with local residents and iron factory workers. This study was seemed to suggest the direction of new genre of public art through Mullae art village case, and considers new political measure plans for culture and art policy.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.2
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• pp.65-72
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• 2011

Since walking and physical activity are critical for older adults to maintain their health, it is important to provide neighborhood environments which encourage their walking in daily life. The purposes of the present study were to investigate walking activity patterns of older people in an urban setting and to identify environmental correlates with walking of older adults. This study examined spatial and temporal patterns of physical activities, environmental barriers and motivations, satisfaction levels and demands on the physical environment. In-depth interviews with older adults over age sixty residing in Seoul metropolitan areas revealed that most respondents have a positive perception on walking in daily life, and many of them walk regularly for their health. A primary purpose of walking for older adults was exercise for health rather than transportation. The study result demonstrated that parks and trails were the most preferred places for walking by older adults, and there is an association between frequency of walking participation and access or convenience to parks, traffic safety, and street lights. Most respondents were concerned about traffic safety when they walk in their neighborhoods due to traffic speeds and unsafe streets. Lack of separate sidewalks or benches, stairs and slopes were barriers to older adults' walking habits. This data suggests that the promotion of walking behavior among older adults, some level of public health action, and community support are needed to ensure safe physical environments within communities.

• Journal of the Korea Society for Simulation
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• v.21 no.3
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• pp.79-88
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• 2012

Recently, the study in efficient operation, maintenance, and equipment-design have been growing rapidly in military industry to meet the required missions. Through out these studies, the importance of Concurrent Spare Parts(CSP) are emphasized. The CSP, which is critical to the operation and maintenance to enhance the availability, is offered together when a equipment is delivered. Despite its significance, th responsibility for determining the range and depth of CSP are done from administrative decision rather than engineering analysis. The purpose of the paper is to optimize the number of CSP per item using simulation and multiple regression. First, the result, as the change of operational availability, was gained from changing the number of change in simulation model. Second, mathematical regression was computed from the input and output data, and the number of CSP was optimized by multiple regression and linear programming; the constraint condition is the cost for optimization. The advantage of this study is to respond with the transition of constraint condition quickly. The cost per item is consistently altered in the development state of equipment. The speed of analysis, that simulation method is continuously performed whenever constraint condition is repeatedly altered, would be down. Therefore, this study is suitable for real development environment. In the future, the study based on the above concept improves the accuracy of optimization by the technical progress of multiple regression.

• Child Health Nursing Research
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• v.20 no.1
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• pp.58-66
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• 2014

Purpose: The purpose of this paper was to describe the attributes of nursing with humor based on an integrative review and to present basic information for developing humor intervention programs for children. Methods: Using combinations of the terms 'nursing' and 'humor' as key words, the researchers searched four electronic databases to relevant identify studies. Thirteen studies were selected through full text screening of related research published in academic journals from January 1993 to April 2013. Results: Through in-depth discussion and investigation of the relevant literature, three components emerged; 1) using instruments of coping for stress relief, 2) symptoms relief through pleasant feeling, and 3) job satisfaction and work improvement of nurse using humor. Conclusion: The results of this study suggest that humor is valuable as a nursing intervention for children and the possibility of bringing about positive results in nursing care if nurses utilize the sense of humor as fully as they can. Therefore, it is critical for nurses to develop a diversity of humor interventions for children as well as measurements to test quality and quantity of humor used in clinical pediatric settings.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.6
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• pp.166-174
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• 2011

The object of this study is to evaluate the structural shear capacity of the PC girder-PC beam joint. The dapped end of PC beam and the ledger of PC girder are usually designed to design load. If the end of PC beam can be designed with continuous end, the dapped end of PC beam and the ledger of PC girder do not need to resist to all loads except dead load and construction load. The experimental program was carried out with 7 specimens containing the variable factors as the anchored method of the hanger bar, design load, be or not exist of ledger bars. As a result, the continuity of the dapped end and the ledger were ensured their safety although the design load was only the dead load and the construction load. The shear critical section was expanded toward the effective depth d, the distance from the supported position of the beam. If the ledger is designed according to PCI Design Handbook, the structural system of the ledger is as to the cantilever slab system. But the ledger of this study is as to the 3 side fixed slab system. Therefore the design of the ledger by PCI Design Handbook will lead to highly conservative results.