• Ecology and Resilient Infrastructure
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• v.3 no.2
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• pp.143-151
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• 2016

Shoreline armoring is a globally used engineering strategy to prevent shoreline erosion along stream, lake and reservoir coastlines. Armoring alters the land-water interface and has the potential to affect shoreline vegetation by changing nearshore geomorphology, hydrology, sediment composition and water quality. We quantified the effects of the artificial disturbances and alternation of the land-water interface on the community structure and distribution of shoreline vegetation in a large reservoir, Uiam Reservoir, Korea. More than 60% of shorelines were disturbed by armoring with retaining wall of concrete block, riprap and gabion in the Uiam Reservoir. The results of detrended correspondence analysis showed that the vegetation structures of the shoreline modified by armoring changed from hydrophyte-dominated to hygrophyte-dominated ecosystems. The shoreline armoring caused the disruption of gradual continuity in the water-land interface and the biological invasion by alien plants. The changes in distribution area of shoreline vegetation showed that the area of hydrophytic vegetation decreased and that of hygrophytic vegetation increased from 2010 to 2013. In conclusion, the human disturbance such as armoring, road construction, recreation etc. could lead to terrestrialization, the loss of transverse continuity and biological invasion in the shoreline vegetation of the Reservoir Uiam. Our findings suggest that redesigning or removing shoreline armoring structures may benefit nearshore hydrophytic vegetation for the conservation of novel shoreline ecosystems.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.874-882
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• 2009

Continuous monitoring of dam performance is essential to earth and rockfill dams safety because it has to be guaranteed for safety during construction period of course and from initial impounding to a long term maintenance period of dam. Among the 31 dams managed by Kwater at present, the proportion of dams being over 20 years after completion of construction is 42% and it is estimated that the loss rate of monitoring devices will be increase as times. Monitoring devices would be impossible to repair since those are mostly installed in the dam body and foundation. If repairing of monitoring devices is possible, the expenditure will be expensive. Therefore reasonable decision making for abandonment, repair and alternation for loss of monitoring devices would be needed through the establishment of key instrument for earth and rockfill dam safety. In this study the process of monitoring for safety were modeled by failure modes of dams, adverse conditions related to failure mode, indicators of adverse condition and monitoring devices The relationship between failure mode and monitoring devices were systematically analyzed and established and evaluation technique for qualifying the importance of monitoring devices were presented.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.4
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• pp.586-591
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• 2009

The marine traffic accidents go on increasing owing to the increment of marine traffic capacity, and the solutions about these matters are vigorously considering by many researchers. When the watch officer navigates to the narrow channel, bend or an area obscured by an intervening obstruction and around the harbour limit he must follow the planned track. The watch officer can safely navigate along the course laid down only when he alters his course in advance before the new course distance earlier than the course alternation point. If we call this point to be changed in advance a turning bearing, the turning bearing is decided according to the direction and the range from the clearing objects. The turning bearing helps the watch officer to determine whether the ship is at wheel-over position or not. The author in this paper suggest how to make and use a curve graph which is decided according to the direction and the distance from the clearing objects. If the watch officer utilize this curve graph he can judge swiftly and precisely whether his ship is at the wheel - over position or not.

• Korean Journal of Applied Biomechanics
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• v.21 no.2
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• pp.189-196
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• 2011

The purpose of this study was to verify the difference in biomechanical variation and pattern of the lower limb between planned and unexpected termination, which is related to the prevention of fatal fall in the elderly. Therefore, selected twenty subjects for each group which composed of females(age: $73.5{\pm}4.63$ year, height: $153.2{\pm}6.46$ cm, body mass: $58.98{\pm}5.82$ kg) and women(age: $23.4{\pm}2.5$ year, height: $164.65{\pm}3.9$ cm, body mass: $58.47{\pm}5.53$ kg) in their twenties. As a result, lower limb's extension moment and power were increased significantly in statistics(p<.05). Also, knee joint power showed instant changes from concentric contraction to eccentric contraction and hip joint power from eccentric contraction to concentric contraction. During unexpected termination there were dramatical increase in eccentric contraction and power(p<.05). In both planned and unexpected termination, ankle joint moment were higher in young group, but the moment of the hip joint were higher in the elderly group(p<.05). In contrast to younger group, there were no changes in knee extension moment in elderly group(p<.05). but showed relatively higher hip joint extension moment and power(p<.05).

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.1071-1072
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• 2006

Maglev using EMS becomes unstable by unexpected big air-gap disturbance. The main causes of the unexpected air-gap disturbance are step-wise rail joint and large distance between rail splices. For the stable operation of the Maglev, the conventional system uses the threshold method, which selects one gap sensor among two gap sensors installed on the magnet to read the gap between magnet and guide rail. But the threshold method with a wide bandwidth makes the discontinuous air-gap signal at the rail joints because of the offset in air gap sensors and/or the step-wise rail joins. Further more, in the case of the one with a narrow bend-width, it makes Maglev system unstable because of frequent alternation. In this paper, a new method using fuzzy rule to reduce air-gap disturbances proposed to improve the stability of Maglev system. It treats the air-gap signal from dual gap sensors effectively to make continuous signal without air gap disturbance. Simulation and experiment results proved that the proposed scheme was effective to reduce air-gap disturbance from dual gap sensors in rail joints.

• International Journal of Advanced Culture Technology
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• v.8 no.1
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• pp.89-97
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• 2020

There are remains of Japanese gardens in Korea which were built during Japanese occupation in 1910-1945. However, systematic database has not been established for location, quantity, nor types of remaining gardens. This study is aimed at defining current status of Japanese gardens built in Korea. By categorizing types of remaining these Japanese gardens, we also aimed to build a systematic data base for Japanese gardens in Korea. This study was co-conducted by researchers from Korea and Japan. The team identified 17 Japanese gardens remaining in South Korea and categorized them into 4 groups; 1) Japanese garden built by Japanese in modern Japanese house in South Korea, 2) Japanese garden built by Korean in traditional Korean garden and 3) Garden built by Japanese in temples in Korea. (at request by Koreans). This categorization reveals information about the inflow of Japanese gardening culture into Korea and deserves to be an important part of modern gardening History. And the rest are 4) Japanese gardens built at Korean residence, but with much damage and alternation. In this paper, we present the findings to serve as preliminary data for defining Korean traditional gardens and for utilizing Japanese gardens in Korea as historical and cultural infrastructure.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.429-438
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• 2020

The emergence of multi-drug resistant, pathogenic methicillin-resistant Staphylococcus aureus (MRSA) is a threat to global health and has created a need for novel functional therapeutic agents. In this study, we evaluated the underlying mechanisms of the anti-MRSA effect of an azaphilone pigment, sclerotiorin (SCL) from Penicillium sclerotiorum. The antimicrobial activity of SCL was evaluated using agar disc diffusion, broth microdilution, time-kill assays and biophysical studies. SCL exhibits selective activity against Gram positive bacteria including MRSA (range, MIC = 128-1028 ㎍/ml) and exhibited rapid bactericidal action against MRSA with a > 4 log reduction in colony forming units within three hours of administration. Biophysical studies, using fluorescent probes and laser or electron microscopy, demonstrated a SCL dose-dependent alternation in membrane potential (62.6 ± 5.0.4% inhibition) and integrity (> 95 ± 2.3%), and the release of UV260 absorbing materials within 60 min (up to 3.2 fold increase, p < 0.01) of exposure. Further, SCL localized to the cytoplasm and hydrolyzed plasmid DNA. While in vitro checkerboard studies revealed that SCL potentiated the antimicrobial activity of topical antimicrobials such as polymixin, neomycin, and bacitracin (Fractional Inhibitory Concentration Index range, 0.26-0.37). Taken together these results suggest that SCL targets the membrane and DNA of MRSA to facilitate its anti-MRSA antimicrobial effect.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.4
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• pp.611-616
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• 2011

The impacts of ultrasonic pretreatment on the biodegradability of domestic sewage sludge were evaluated through a series of anaerobic digestion experiments in batch system. The gas and methane production from the sludge samples pretreated by an ultrasonic tool with different durations were measured with time. Although the biogas production increased with the extent of sludge solubilization and the period of ultrasonic pretreatment, the enhancement of sludge biodegradability was much more sensitive to the pretreatment for the relatively short periods. Most of the enhanced biodegradability by the pretreatment was appeared in the early stage of anaerobic digestion, less than 6 days. The maximum biogas production per day was observed between 4 to 6 days when the sludge was pretreated less than 10 minutes while it was obtained in the beginning for the sludge pretreated longer periods. The results suggest that the repeated alternation of low strength ultrasonic pretreatment and anaerobic digestion may be more effective than the combination of one time pretreatment for a relatively long period and following anaerobic digestion.

• The Korean Journal of Emergency Medical Services
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• v.17 no.1
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• pp.9-19
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• 2013

Purpose : The purpose of this study was to investigate the variation of elapsed time in the cardiopulmonary resuscitation (CPR) quality and the fatigue in continuous CPR by single rescuer. This study will provide basic data about the time for the alternation of the CPR providers. Methods : The volunteer students having healthcare provider certification were recruited from the department of emergency medical service. The students performed 30:2 CPR for 20 minutes, and the data were recorded and analyzed. Metrics were based on the 2010 American Heart Association (AHA) Guidelines, and the CPR continued without any feedback. Results : Among the indicators of CPR, the accuracy and the depth of chest compressions decreased after about 5.3 minutes, and the rate increased approximately after 6.8 minutes. Changes in clinical indicators appeared, and fatigue increased after about 3 minutes. According to the increase in fatigue level, the changes in the CPR indicators and clinical indicators showed up, and these results proved to be statistically significant. However, there were no associations among the time, fatigue, and gender. Conclusion : Even though the times of changes in the indicators appeared differently, the times of changes in fatigue and CPR quality were able to be confirmed.

• International journal of advanced smart convergence
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• v.6 no.4
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• pp.41-49
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• 2017

In this paper I applies Borer (1993)'s way of classifying English intransitive action verbs such as 'run', walk, among many others, to the corresponding Korean intransitive action verbs such as 'tali-ta' and 'keət-ta', and show how they are different from - or similar with - each other in terms of syntactic structures and verb classification. Unlike the English verb 'run' which can be classified into an unaccusative verb as well as an unergative verb in Borer's theory, the corresponding Korean verbs 'tali-ta' or 't'wi-ta' can behave not only as an unergative and unauucsative verb, but also it can behave as a transitive verb. Though Borer's perspective on classification of verb types may be thought of as somewhat radical mostly due to its heavy dependency on aspectual representation of a whole sentence which a verb is just part of, it is clearly suggesting a new and great insight into the controversial topic of classification of verb types. So it is worth adopting this insightful perspective for the analysis of corresponding Korean verbs and seeing if it also works for the Korean ones.