• Polymer(Korea)
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• v.34 no.4
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• pp.363-368
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• 2010

Adequate acidic environment in wound healing prevents the inflammation of virus, increases the cell activity, promotes cell proliferation and regular rearrangement of fibroblast, and results in matured epithelialization. In this study, we prepared dressing materials consisting of pectin and carboxymethylcellulose (CMC) with varied ratios. These dressing materials showed different pH values according to the composition ratio. The effect of acidity of pectin/CMC dressing materials on wound healing rates, degree of epithelialization, collagen deposition, and so on, in 3 types of wound models (fresh surgical wounds, $3^{rd}$ degree burn wounds, and infection wounds) were investigated by animal tests. From the results of wound contraction, wound healing, and epithelialization, it can be deduced that dressing material having pectin/CMC ratio of 16/19 (pH 4.67) is most effective among the 3 types of wound models.

• Korean Journal of Plant Resources
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• v.22 no.2
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• pp.136-144
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• 2009

Germination tests on 3 species that have potential for use as sprout vegetables, such as Coreopsis tinctoria, Saussurea pulchella, and Matricaria recutica, were conducted for 20 days under different temperatures of $15{\sim}30^{\circ}C$, and conditions of light and dark. C. tinctoria showed germination of 83% under $15^{\circ}C$ and dark condition after 4 days, S. pulchella 51.7% under $25^{\circ}C$ and light condition after 20 days, and M. recutica 90.3% under $25^{\circ}C$ and dark condition after 4 days. To investigate optimum plantlet size before greening treatment, seeds germinated were allowed to grow under darkness. The optimum growth of C. tinctoria was obtained under $30^{\circ}C$ after 5 days, S. pulchella under $25^{\circ}C$ after 6 days, and M. recutica under $20^{\circ}C$ after 6 days. Greening treatment resulted in diminished longitudinal growth, but C. tinctoria and S. pulchella showed more vigorous latitudinal growth. Days required before marketing as sprout vegetables were different according to species - Three days of greening was good for C. tinctoria, 2 for S. pulchella, no greening for M. recutica. Generally, tightly sealed containers for minimum water loss were recommended for storage of sprout vegetables after harvest. However, storage methods for each species were different depending on various factors like temperature of storage, presence of ventilation holes of storage packages and forms of marketing. More detailed research for above 3 species is proposed.

• Journal of the Korean Society of Hazard Mitigation
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• v.11 no.1
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• pp.51-57
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• 2011

Irregular distributions of limestone cavity in Gang-Won province area may cause unexpected accidents from reduced serviceability or failure of structure. It is requested that an appropriate ground reinforcement method should be used to improve bearing capacity of structure, and the method should also be satisfied with environmental requirements. Among several methods used for foundation constructions in cavity area, Rod Jet Pile(RJP) method has been widely used. While the RJP method was used to improve bearing capacity for the railway bridge foundations, water pollutions of drinking water as well as fishery located adjacent to this project area were occurred. The main reason of the water pollution was cement runoff used in cement mortar during injecting material in RJP method. Laboratory tests were performed to prevent water pollution. The compaction mortar method using low movable material was selected for this project. The quality of water at a fishery adjacent to the site and the compressive strength of cores taken from the construction site were measured. Test results show that the water pollutions was minimized, and the average compressive strength of foundation material was over 5 MPa. As a result of this study, compaction mortar method can be used to ensure the bearing capacity of foundation and to prevent environment pollutions.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.103-111
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• 2021

The purpose of this study is to study a method for preventing collisions of multiple drones in controlled airspace. As a result of the study, it was proved that it is appropriate as a method to control drone collisions after setting accurate information on the ROI (Region of Interest) area estimated based on the expected drone path and time in the control system as a method to avoid drone collision. As a result of the empirical analysis, the diameter of the flight path of the operating drone should be selected to reduce the risk of collision, and the change in the departure time and operating speed of the operating drone did not act as an influencing factor in the collision. In addition, it has been demonstrated that providing flight priority is one of the appropriate methods as a countermeasure to avoid collisions. For collision avoidance methods, not only drone sensor-based collision avoidance, but also collision avoidance can be doubled by monitoring and predicting collisions in the control system and performing real-time control. This study is meaningful in that it provided an idea for a method for preventing collisions of multiple drones in controlled airspace and conducted practical tests. This helps to solve the problem of collisions that occur when multiple drones of different types are operating based on the control system. This study will contribute to the development of related industries by preventing accidents caused by drone collisions and providing a safe drone operation environment.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.9
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• pp.721-736
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• 2019

In this paper, the behavior of the fire smoke due to the operation of the ventilation systems when the fire occurred in the underground station (6 basement floors) and the tunnel at the great depth was measured. Fire smoke was generated by using a smoke generator which realized heat buoyancy effect by using hot air blower. The two locations of the fire were selected on the platform and on the platform of the tunnel located outside the screen door. A ventilation mode is generally used in which smoke is exhausted through a vent hole provided in a platform when a platform fire occurs. The tests were performed by operating the exhaust through the ventilation holes of the tunnel part located at both ends of the platform. The smoke density and the wind speed/velocity were measured at various positions, and the videos were taken to analyze the movement and smoke of the smoke. In both cases for fire inside the platform and in the railway tunnel, due to the ventilation mode operation of the fan for the platform and the exhaust of the fans in the tunnel smoke were well exhausted and the smoke propagation to the area near the smoke zone was suppressed. The smoke-control mode, which is applied to both fans for the platform and fans for in the tunnel at both ends of the platform, can provide a safer evacuation environment to the passengers from the fire smoke when the platform fire or fire train stops.

• Korean Public Health Research
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• v.44 no.4
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• pp.99-109
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• 2018

Objective : Health literacy (HL) is, defined as "the degree to which individuals have the capacity to obtain, process, and understand basic health information and services needed to make appropriate health decisions." Being old is one of the main risk factors with limited health literacy. This study aims to adapt Chew's health literacy scale into the Korean language and validate the scale for the use of the elderly. Methods : Data were drawn from the '2016 Seoul Survey on Elderly Health and Functional Assessment, which includes a total of 725 people aged 60 to 79. The sample was randomly divided into two groups for reliability and validity tests of the modified Chew's scale of 8 items. The Korean version of the questionnaire was developed by group translation, expert reviews, and forward-backward translation. Exploratory and confirmatory factor analyses were conducted to assess and validate the factor structure of the scale. Results : Results suggest the two-factor structure ("Understanding" and "Applying" of HL) with 8 items. Exploratory factor analyses of the first sample (n=400) revealed that the internal reliability of the scale was high (Cronbach's ${\alpha}=.904$). Principal axis factoring extracted two factors ("Understanding" and "Applying" of HL) and explained 78.3% of total variance (KMO=.872, Bartlett's ${\chi}^2=2431.3$, df=28, p<.001). Confirmatory factor analysis of the second sample (n=325) was performed and the two-factor model was supported (GFI=.960, CFI=.979, TLI=.969, RMSEA=0.075). Conclusions : This study provides evidence for adequate criterion and validity of the health literacy scale for the community dwelling elderly in Korea.

• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.73-85
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• 2019

Since the beginning of a new century, many Korean construction and engineering companies are facing a very dynamic and fast changing business environment which includes severe competition, higher risk, economic depression, declining revenues and profits, etc. In order to cope with these challenges, they need to secure special capabilities to actively adapt to the paradigm changes. One of those capabilities could be project management capability which allows us to manage organizational resources dynamically and integratively based on project portfolio management concept. The objective of this study is to investigate how the dynamic capability of a project-based organization to control the resource affects the firm performance and the competitive advantages. Data was collected from the construction and engineering companies in South Korea by using survey questionnaire, and analyzed for empirical tests by using statistical methods such as structural equation modelling and path analysis. The results showed that the organizational resources, if they had the VRIN characteristics, would have positive impacts on creating the dynamic capabilities for project organization. In turn, the dynamic capabilities of a project organization would have impacts on improving business performance and creating competitive advantages. Also, it was found that the organizational resources may have direct impact on business performance and competitive advantages. The academic contribution of this study is that it attempts to integrate resource based view and the dynamic capability theory about creating competitive advantages for project based organization. This study also provided practical implications to the companies in construction industry by showing how to use organizational resources strategically to create competitive advantages.

• Journal of the Korean GEO-environmental Society
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• v.20 no.2
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• pp.69-79
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• 2019

The coastal area forms various sedimentary layers according to the environmental conditions such as the topography and geological features of the upper region of the river, ocean currents, and river mouth. Therefore, identifying the characteristics of the marine clay deposited in the coastal area plays a key role in the investigation of the formation of soft ground. In general, alluvial grounds are formed by a variety of factors such as changes in topography and natural environment, they have very diverse qualities depending on the deposited region or sedimentation conditions. The most important thing for the construction of social infrastructures in soft ground areas is economical and efficient treatment of soft ground. In this study, the author collected data from diverse laboratory and field tests on five areas in western and southern offshore with relatively high reliability, and then statistically analyzed them, thereby presenting standard constants for construction design. Correlation between design parameters such as over consolidation ratio, preconsolidation pressure was analyzed using linear and non-linear regression analyses. Also, proposed distribution characteristics of design parameters in consideration of each region's uncertainty through statistical analyses such as normality verification, outlier removal.

• Ecology and Resilient Infrastructure
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• v.5 no.4
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• pp.257-263
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• 2018

This study is to develop a GSTM (Green infrastructure Surface Temperature Measurment) equipment for reducing the surface temperature of GI by using LID Method. The tests were conducted including GI products such as Greening block, Pervious Block, Soil Block and so on. The GSTM equipment developed by considering the literature surveys are characterized as follows. The non-contact infrared temperature sensor was used to measure the surface temperature, and it was improved to measure the overall average temperature including the center and the corner temperature of the specimen. The developed GSTM equipment was used to compare performance of asphalt and GI products. As a result, the Greening Block show a high difference of $18.4^{\circ}C$ and it contributes to the decrease of surface temperature.

• Tunnel and Underground Space
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• v.28 no.6
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• pp.596-608
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• 2018

As urban infrastructure is aging, the possibility of accidents due to the failures or breakdowns of infrastructure increases. Especially, aging underground infrastructures like sewer pipes, waterworks, and subway have a potential to cause an urban ground sink. Urban ground sink is defined just as a local and erratic collapse occurred by underground cavity due to soil erosion or soil loss, which is separated from a sinkhole in soluble bedrock such as limestone. The conventional measurements such as differential settlement gauge, inclinometer or earth pressure gauge have a shortcoming just to provide point measurements with short coverage. Therefore, these methods are not adequate for monitoring of an erratic subsidence caused by underground cavity due to soil erosion or soil loss which occurring at unspecified time and location. Therefore, an alternative technology is required to detect a change of underground physical condition in real time. In this study, the feasibility of a novel magnetic resonance based monitoring method is investigated through laboratory tests, where the changes of path loss (S21) were measured under various testing conditions: media including air, water, and soil, resonant frequency, impedance, and distances between transmitter (TX) and receiver (RX). Theoretically, the transfer characteristic of magnetic field is known to be independent of the density of the medium. However, the results of the test showed the meaningful differences in the path loss (S21) under the different conditions of medium. And it is found that the reflection coefficient showed the more distinct differences over the testing conditions than the path loss. In particular, input reflection coefficient (S11) is more distinguishable than output reflection coefficient (S22).