• Ecology and Resilient Infrastructure
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• v.7 no.3
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• pp.189-198
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• 2020

Wetlands, which provide various ecological services, have been regarded as an important nature-based solution for, for example, sustainable water quality improvement and buffering of impacts from climate change. Although the importance of conserving wetlands to reduce the impacts of various perturbations (e.g., changes of land use, climate, and hydrology) has been acknowledged, the possibility of applying these efforts as a nature-based solution in a macro-scale (e.g., landscape) has been insufficient. In this study, we examine the possibility of ecological network analysis that provides an engineering solution as a nature-based solution. Specifically, we analyzed how land use change affects the structural and functional characteristics (connectivity, network efficiency, and clustering coefficient) of the ecological networks by using the ecological networks generated by multiple dispersal models of the hypothetical inhabiting species in wetlandscape. Changes in ecological network characteristics were analyzed through simultaneously removing wetlands, with two initial conditions for surface area, in the zones where land use change occurs. We set a total number of four zones of land use change with different wetland densities. All analyses showed that mean degree and network efficiency were significantly reduced when wetlands in the zones with high wetland density were removed, and this phenomenon was intensified especially when zones contained hubs (nodes with high degree). On the other hand, we observed the clustering coefficient to increase. We suggest our approach for assessing the impacts of land use change on ecological networks, and with additional analysis on betweenness centrality, we expect it can provide a nature-based engineering solution for creating alternative wetlands.

• Journal of Korean Society of Steel Construction
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• v.22 no.4
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• pp.325-334
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• 2010

In this study, an unbraced five-story steel-framed structure was designed in accordance with KBC2005 to understand the features of structural behavior for the arrangement of semi-rigid connections. A pushover analysis of the structural models was performed, wherein all the connections were idealized as fully rigid and semi-rigid. Additionally, horizontal and vertical arrangements of the semi-rigid connection were adopted for the models. A fiber model was utilized for the moment-curvature relationship of the steel beam and the column, and a three-parameter power model was adopted for the moment-rotation angle of the semi-rigid connection. The top displacement, base-shear force, required ductility for the connection, sequence of the plastic hinge, and design factors such as the overstrength factor, ductility factor, and response modification coefficient were investigated using the pushover analysis of a 2D structure subjected to the equivalent static lateral force of KBC2005. The partial arrangement of the semi-rigid connection was found to have secured higher strength and lateral stiffness than that of the A-Semi frame, and greater ductility than the A-Rigid frame. The TSD connection was found suitable for use for economy and safety in the sample structure.

• Journal of Korean Society of Steel Construction
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• v.22 no.2
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• pp.129-137
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• 2010

In this study, a five-story steel frame was designed in accordance with KBC2005 to evaluate the effect of the beam-column connection on the structural behavior. The connections were designed as a fully rigid connection and as a semirigid connection. A fiber model was utilized to describe the moment-curvature relationship of the steel beam and column, and a three-parameter power model was adopted for the moment-rotation angle of the semirigid connection. To evaluate the effects of higher modes on structural behavior, the structure was subjected to a KBC2005-equivalent lateral load and lateral loads considering higher modes. The structure was idealized as a separate 2D frame and as a connected 2D frame. The pushover analysis of 2D frames for the lateral load yielded the top displacement-base shear force, design coefficients such as overstrength factor, ductility ratio, and response modification coefficient, demanded ductility ratio for the semirigid connection,and distribution of plastic hinges. The sample structure showed a greater response modification coefficient than KBC2005, the higher modes were found to have few effects on the coefficient, and the lateral load of KBC2005 was found to be conservative. The TSD connection was estimated to secure economy and safety in the sample structure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.157-163
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• 2016

BIM is currently applied in some domestic construction firms, but it is not being actively utilized due to changes in working environments and qualms about new studies. In order to utilize a BIM model in the design phase, process information is needed during construction, but the input system and utilization method of the process information's state are not complete. Therefore, we propose a BIM template for construction progress management that can show basic BIM information as the construction progresses in an easy and convenient way. This method will facilitate the adoption of BIM and enhance the productivity of construction companies. To this end, we designed a progress explorer for step-by-step progress and work schedules, and we generated three-dimensional views and a progress list by applying unit information (primary units, part units, and detail units) of the work breakdown structure (WBS) to the parameters. To use the BIM template, work progress information is input to the BIM modeling objects through Dynamo. We also used Dynamo for quick and easy calculation of the quantity of materials needed for construction work. To test the BIM template, we applied it to an actual project and evaluated its visibility and a progress list. The results showed that the proposed BIM template facilitates progress management of a project and can thus facilitate the adoption of BIM and improve the productivity of construction companies.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.299-299
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• 2009

유기농업에서 유기자원을 이용하여 적정량의 양분을 공급하기 위해서는 먼저 유기자원의 무기화특성을 고려하여야 한다. 토성, 기온, 재배형태 등 다양한 요인을 고려하면서 무기화모델을 이용하여 유기농업에서 많이 사용되고 있는 유기질비료와 작물잔사 등을 대상으로 잠재 무기화가능 질소량(PMN, Potentially mineralizabe nitrogen)을 추정하였다. 실험은 실내에서 항온 배양하여 유기자원별 질소 무기화 양상을 분석함으로서 대상 유기자원의 PMN 및 무기화 속도를 도출하였다. 실험재료는 팜박, 피마자박, 팽화왕겨, 토마토, 수박, 감자, 마늘 등 7종을 대상으로 $20^{\circ}C,\;25^{\circ}C,\;30^{\circ}C$ 조건에서 하였으며, 최대수분보유량의 60% 수준으로 하여 사양토 및 식양토 조건에서 실험하였다. 유기자원은 토양 100g에 질소 30kg/10a 해당량을 시용하여 112일까지 항온하였다. 토성별 무기화량은 식양토 보다 사양토에서 다소 높은 경향을 보였다. 또한 항온온도가 높을수록 무기화량이 증가하였다. 유기자원별로는 피마자박에서 높았고, 팽화왕겨는 낮은 경향이었다. 유기자원이 처리된 것에서 토양 자체의 무기화량을 뺀 순무기화량은 피마자박, 토마토잔사, 감자잔사가 항온초기부터 무기화가 진행되었으며, 수박잔사, 마늘잔사는 항온 초기에 음의 값을 가지는 유기화 과정을 거친 후 항온 60일에서 80일 사이에서 무기화가 진행되었고 팽화왕겨의 경우 항온 11일까지 유기화가 계속되었다. PMN 및 무기화속도를 추정하기 위하여 반응속도식을 이용하였으며, 모델의 적합도를 높이기 위하여 이중지수모형을 이용하여 매개변수를 결정하고 무기화경향을 예측한 결과 PMN은 피마자박>마늘잔사=팜박>수박잔사=토마토잔사>감자잔사의 순이었다. 또한 유기자원의 무기화량과 C/N율과는 부의 상관관계($r^2$=0.8653)를 나타내었다. 요소의 PMN(135.6mg/kg)에 대한 유기자원별 PMN의 상대적 비율은 피마자박이 100%, 팜박과 마늘잔사가 81%, 토마토, 수박 및 감자잔사가 28~65% 수준이었다.

• Korean Journal of Food Science and Technology
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• v.48 no.6
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• pp.597-603
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• 2016

This study aimed to explore the protective effect of Gastrodia elata (GE) in an HCl/ethanol induced acute gastritis model by differing the steaming time. The samples GE1 (GE by steaming for 1 time) and GE9 (GE by steaming for 9 times), were selected based on the results of HPLC analysis, free radical scavenging activities, and total phenol and flavonoid contents. To evaluate the anti-inflammatory effect of GE, ICR mice were divided into 5 groups; normal mice (Nor), gastritic mice with distilled water (Con), gastritic mice with 100 mg/kg GE1, gastritic mice with 100 mg/kg GE9 and gastritic mice with 10 mg/kg sucralfate (SC). HCl/ethanol-induced gastric mucosal injury was markedly improved by GE9 treatment as observed during histological evaluation. The increased reactive oxygen species levels in the serum were diminished by GE9 treatment. Furthermore, peroxynitrite levels of the stomach tissue were decreased in the GE9-treated group. The analyses of stomach proteins indicated that GE9 treatment effectively reduced inflammatory cytokine levels as compared to that by GE1 treatment. These results suggest that GE9 improves health during acute gastritis.

• Journal of The Korean Association For Science Education
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• v.36 no.4
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• pp.581-589
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• 2016

This research aims to find directions for character education in science education and to analyze Nature-Study theoretically as one of the ways to implement character education in science education. In order to accomplish this, references for character education were collected and analyzed to derive the directions for character education in science education, and then the results were verified by expert workshops composed of 2 science education experts and 4 PhD students. Through the consideration of references for Nature-Study in terms of character education, we supposed to confirm that Nature-Study is an efficient way to implement character education in science education. The research resulted in the following: First, science education should establish it's own role in character education by expanding the domains of value and realizing practice-centered character education. Accordingly, 'Expanded model of character education (The domains of the value)' was developed on the basis of 'formation of relationships' with 'nature & environment, spiritual object' and 'The practice-centered character manifested mechanism' empathized 'formation of relationships' and 'practice' was also diagramed. Second, Nature-Study empathized 'Science Education through Nature' can be one of the efficient ways to implement character education in science education. Nature-Study corresponds with the directions of character education in science education because Nature-Study aims for character education in it's educational purpose and emphasizes 'formation of relationships' with 'nature & environment' and 'practice' in the real world. In conclusion, science education should establish it's own role in character education by expanding the domains of value and realizing the practice-centered character education and Nature-Study is efficient ways to implement character education in science education.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.4
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• pp.85-93
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• 2011

A parametric study is conducted for the design of segmented arc plasma torch with the input power and current of 0.4 MW and 300 A, respectively. For this purpose, we use the analytical relationship between input power, current condition, plasma temperature, inner diameter (R) and length (L) of the torch constrictor based on arc channel model. The results reveal that arc plasma temperatures increase monotonically as ��L increases or R decreases for the ranges of R ${\leq}$ 7.5 mm and L ${\leq}$ 1.25 m. For larger valuse of ��R and L than 7.5 mm and 1.25 m, respectively, however, they show non-linear behavior corresponding to the variations of ��L, which stands for the generation of unstable arc plasma. From this parametric study, optimum ranges of R and L are suggested as 5.5 mm ${\leq}$ R ${\leq}$ 7.5 mm and 0.25 m ${\leq}$ L ${\leq}$ 0.5 m for 0.4 MW class segmented arc plasma torch, under which stable arc plasma can be achieved at the input currents of ~300 A.

• The Journal of the Korea Contents Association
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• v.18 no.6
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• pp.155-168
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• 2018

The purpose of this study was to investigate characteristics of Blockchain to introduce Blockchain technology to the medical industry. Thus, the 5 factors such as Security, Availability, Reliability, Diversity and Economic feasibility were used as the characteristics of Blockchain, which are independent variable, based on precedent studies. Also, Technology Acceptance Model(TAM) that are widely used in the research on Acceptance Intention in order to introduce new technology accept was utilized for intervening variable and dependent variable. For the purpose of this study, the health professionals and ordinary people were classified into health care providers and medical service consumers respectively to conduct survey and comparative analysis. The researching findings discovered that Hypothesis1-1(Security-Perceived Easiness-Acceptance Intention), Hypothesis2-1(Security-Perceived Usefulness-Acceptance Intention) and Hypothesis 3-1(Security-Perceived Easiness-Perceived Usefulness-Acceptance Intention) were rejected in all participants including health professionals and ordinary people. Additionally, all characteristics of Blockchain such as Availability, Reliability, Diversity and Economic feasibility were rejected in Hypothesis3-2 and Hypothesis 3-5 that pass through Easiness and Usefulness to Acceptance Intention, in case of the medical service consumers. Thus, this study discovered and confirmed that there's difference between the health care providers and medical service in the characteristics of Blockchain, as they pass through Perceived Easiness and Perceived Usefulness to Acceptance Intention. The significance of this study can be found, as it suggested activation plan through empirical analysis, which was hardly ever used in the study on Blockchain activation.

• Journal of the Korean Society for Railway
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• v.20 no.4
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• pp.521-528
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• 2017

In this study, vertical loading tests were conducted to investigate the nonlinear behaviors of the fastening systems that have generally been used in the concrete track of domestic railway lines. Nonlinear load-displacement curve models were derived based on the test results. The uplift forces generated in the fastening systems were evaluated by applying the derived nonlinear models as well as the existing linear models. The influence of the factors on the maximum uplift force of the fastening system was analyzed through a parameter study on the distance between neighboring sleepers, the horizontal distance between the center of the bearing and the nearest fastening system from the deck end, and the height of the bridge girder. From the evaluation results it is known that, for economical track and bridge design, due to deck end deformation, it is necessary to consider the nonlinear behavior of the fastening system in the calculation of the uplift force of the fastening systems.