• Journal of Ecology and Environment
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• v.39 no.1
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• pp.51-60
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• 2016

This study was conducted to examine litter fall, litter decomposition, and a short-term nutrient (C, N, P, K, Ca, and Mg) status for one year at various levels of basal area (21.4, 27.0, 30.8, 37.0, 42.1, and 46.7 m² ha^-1) in approximately 40-yearold red pine (Pinus densiflora S. et Z.) stands in the Hwangmaesan mountain forest in Korea. Monthly fluxes of litter fall components such as needles, broad leaves, branches, bark and total litter fall followed a similar pattern at various levels of basal area. Mean annual needle, bark and total litter fall fluxes were positively correlated with increased basal area (p<0.05), but the woody litter such as branches and cones was not correlated with basal area. Carbon and K concentrations of needle litter were negatively correlated with increased basal area, while nutrient (C, N, P, K, Ca, and Mg) fluxes were positively correlated with the basal area treatments. Remaining mass, N and P concentration and remaining N and P stocks in decomposing needle litter were not affected by the basal area. However, the concentration and stocks remaining of K, Ca, and Mg from decomposing litter were positively correlated with increased basal area during the initial three months of decomposition. The results indicate that basal area has an impact on nutrient cycles through change in litter fall and litter decomposition processes; thus, the dynamics of nutrient cycles based on a stand scale could differ considerably with different levels of basal area in red pine stands.

• Korean Journal of Mineralogy and Petrology
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• v.33 no.1
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• pp.73-86
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• 2020

The materials generating from volcanic eruption are volcanic gases, lavas and pyroclastic materials. Volcanic ash which has small-grain size (< 2 mm in diameter) can be moved easily and disperse widely, thus it may affect to communities across hundreds of square kilometers. The impacts from volcanic ash fall on people, structures, equipments, plants and livestock largely depend on ash thickness. According to increasing ash thickness, the intensity and area of damage may increase and affect significant damages not to human health but also to infrastructures. To reduce the impacts from volcanic ash fall, we have to establish the guidances about the nature and extent of the hazard and prepare the actions to increase abilities of communities to manage hazard. Although we don't have any experience caused by volcanic ash fall during and after volcanic eruption, we need to prepare the impacts of volcanic ash fall for future eruption in the areas surrounding Korea.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.2
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• pp.84-89
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• 2021

Recently, shipyards are making many efforts to reduce the number of the mounted blocks by increasing the block size. This is to improve productivity and reduce related costs by minimizing block movement and shortening the building period. However, as the blocks become larger, the weight increases considerably. If the target block has a damage due to an unexpected accident during block lifting, it may seriously cause a problem of the reusability of the block. In this study, a large-sized block of the offshore structure weighing 480 tons was lifting with a total of seven sling belts, and one sling belt was broken while it was moving, resulting in a situation in which a part of the edge of the block collided with the ground. The aim of this paper is to verify the structural integrity of the block that directly collides with the ground in the form of free fall due to the sling breakage. Considering that the hook loads acting on several sling belts holding the block are redistributed when a sling belt is broken, the hook loads were recalculated at the angle just before the sling breakage. These loads were used to check the safety of the sling belts. In addition, FE analysis was performed by calculating the amount of impact from the free fall condition, obtaining the impact area by using Hertz's contact theory, and then applying the impact load to the area.

• Proceedings of the KAIS Fall Conference
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• 2006.11a
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• pp.176-179
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• 2006

We are using COS to purpose blocking the excess current and to protect the transformer. But the fuse of COS is melt due to the overload if the excess current flows and it destroy an air severing relations to clear as strong arc happens. Such phenomenon induces an impact ambient noise and it gives the circumstance area resident or pedestrian the fear. Thus, We are the actual circumstances which an ambient noise countermeasure establishment have desired urgently. In this study, we grasp the characteristic of an impact ambient noise which a COS fuse happens the melting and study the method to reduce an impact ambient noise.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.621-628
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• 2011

Health and safety in the construction industry continue to fall behind many industries despite much effort to improve the status. A considerable amount of research has been conducted to try and contribute to addressing the problem of health and safety (H&S) in the construction industry. A number of studies have looked at the role of various construction project stakeholders and their contribution to H&S. However there is no clear identification of the extent to which various stakeholders could contribute and therefore influence the outcome of H&S on construction projects. In view of the above, the current Delphi study went a little bit further and sought to establish the impact significance of construction clients and designers on H&S. This paper will present findings from the study which is the impact significance of clients and designers on H&S consideration throughout the project life cycle.

• Proceedings of the KAIS Fall Conference
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• 2012.05a
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• pp.397-400
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• 2012

본 논문에서는 비즈니스 모델이 인터넷 기업의 성공에 어떠한 영향을 미치는지 분석하고자 한다. 이를 위하여 기존 비즈니스 모델 연구를 종합하여 비즈니스 모델을 정의하고, 주요 인터넷 기업 사례를 분석하고, 귀납적 추론 기법을 적용하여 인터넷 기업의 성공에 영향을 미치는 비즈니스 모델의 전략적 요인이 무엇인지 제시하고자 한다.

• Proceedings of the KAIS Fall Conference
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• 2011.05b
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• pp.901-903
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• 2011

본 논문에서는 산업연관표를 활용한 관광산업의 유발승수효과 및 경제적 파급효과를 분석함으로써 관광산업과 다른 산업과의 경제적 효과를 비교분석한다. 다른 산업과의 비교분석을 통해 관광정책의사 결정을 위한 기초자료를 제공하는 데 연구의 주된 목적이 있다.

• Proceedings of the KAIS Fall Conference
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• 2011.12a
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• pp.43-45
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• 2011

본 논문에서는 1970년대 한국 대중음악의 주류 역할을 담당했던 포크음악의 태동과 발전을 이끌어 낸 번안가요와의 관계를 연구하고자 한다.

• Journal of Environmental Impact Assessment
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• v.5 no.1
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• pp.31-45
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• 1996

This paper presents the results from a hydrodynamic model study to predict the impacts of coastal reclamation in Pusan harbor system using RMA2 which is a tidal flow model of the US Army Corps of Engineers' TABS-2 system. A finite element mesh was constructed and refined to cover the complicated geometry of Pusan harbor system and the proposed reclamation area. The model was calibrated to tidal elevations and currents measured during spring fall syzygys. Under the three different tidal conditions including summer winter syzygys, spring fall quarters, and summer winter quarters, the model predictions were compared with the field measurements both in tidal elevation and current. In all cases, there were excellent agreements between the model predictions and the field measurements. The validated model was then used to predict the changes in tidal current and elevation that might occur due to the coastal reclamation. It was predicted that there would be no change in tidal elevation of this system after the reclamation. In tidal current, however, discernible changes were predicted near the proposed reclamation area both in magnitude and direction.

• International Journal of Safety
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• v.10 no.2
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• pp.21-26
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• 2011

In 2001, an independent official board was constituted in Japan to investigate aircraft and railway accidents. In the past 10 years, many accidents and serious incidents have been investigated and these official reports were published by the board, on which the author had sat for 9 years as boarding member. In the interim, there were several train disasters which mocked our trust in railways and also many apparent trivial incidents. In recent years, serious incidents, which a door of running rail cars opens suddenly with some trouble, happen 2 or 3 times in a year. For the past 10 years, such incidents have happened 14 times and 13 cases of them were closed by the board mentioned above. In these 13 cases, no one fell off the rail car, so that the death toll was none luckily. In this paper, these 13 serious incidents are picked up among all the reports published by the board and outlined using some tables. Especially, fall accidents of passengers are discussed mainly from the view point of impact force and duration time. Then, the equation of HIC (Head Injury Criteria) and the risk curves in terms of the HIC are dealt with properly.