• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.262-262
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• 2017

• Nuclear industry
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• v.14 no.1 s.131
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• pp.22-25
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• 1994

• Journal of Korea Fishing Vessel Association
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• v.2
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• pp.42-47
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• 1980

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.05a
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• pp.213-216
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• 2002

산소가 없는 상태에서 비교적 낮은 온도에서의 열, 충격 등에 의해 용이하게 발화, 연소하는 불안정한 물질에 의한 사고는 이전부터 많이 알려져 있다. 최근에는 fine chemical 분야의 발전에 따라 그 위험성이 인식되지 않은 채 제조되는 불안정한 물질이 늘고 있다［1-2］.(중략)

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.2
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• pp.115-131
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• 2011

Recently, considering the aspects of disaster prevention and environmental damage, the construction of a twin tunnel is increasing. When constructing a twin tunnel, the stresses are concentrated at the pillar so that stability of the tunnel is decreased. Since the previous studies on the behavior of a twin tunnel pillar are mainly restricted to the estimation of the tunnel behavior and the analysis of surface settlement, there is a limit to a quantitative stability estimation of the pillar. Therefore, it was quantitatively investigated how the pillar width of a twin tunnel affects its stability. To ensure this end, global tunnel safety factors obtained numerically using shear strength reduction technique, local safety factors of a pillar using the equation that Matsuda et al. suggested, and strength/stress ratios of the pillar were estimated and their results were analyzed for two sections with different rock covers. For a reasonable design of a twin tunnel pillar, it was turned out that strength/stress ratio, the local pillar safety factor, and global tunnel safety factor should be used interrelatedly rather than independently.

• Journal of Korean Tunnelling and Underground Space Association
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• v.8 no.4
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• pp.355-363
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• 2006

In this study, it was analyzed how the pore pressure behind a subsea tunnel influences on the stability of the tunnel. The tunnel is located in the soft rock layer, and a soft sandy layer and weathered soil layer are located on the top of it. Coupled numerical analyses are performed for both drained and undrained condition with varying coefficients of lateral earth pressure. In the case of undrained conditions, the stability of the tunnel was analyzed with different thicknesses of shotcrete. On the other hand, a sensitivity analysis was performed with different hydraulic conductivities and porosities of the shotcrete for the drained conditions. The stability of a subsea tunnel was evaluated in terms of safety factor suggested by You et al.(2000, 2001, 2005) based on the shear strength reduction technique. In this paper, the safety factor of a tunnel was calculated under steady state flow condition during hydro-mechanical coupled analysis. As a result, it was found that the stability of a subsea tunnel could be rather increased by allowing a proper amount of groundwater inflow into a subsea tunnel.

• Journal of the KSME
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• v.50 no.5
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• pp.44-47
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• 2010

• Tunnel and Underground Space
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• v.24 no.3
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• pp.187-200
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• 2014

After excavation or blasting, rock properties within an excavation damaged zone can be perpetually weakened on account of stress redistribution or blasting impact. In the present study, the excavation damaged zone is applied to a rock slope. The objective of this research is to compare the mechanical stability of the rock slope depending on the presence of the damaged zone using 2-dimensional modeling and analyze factors affecting factor-of-safety. From the modeling, it was founded that the mechanical stability of the rock slope is significantly dependent on the presence of the damaged zone. In particular, factor-of-safety with a consideration of the damaged zone decreased by approximately 49.4% in comparison with no damaged zone. Factor analysis by fractional factorial design was carried out on factor-of-safety. It showed that the key parameters affecting factor-of-safety are angle of the slope, cohesion, internal friction angle and height.

• Bulletin of Food Technology
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• v.12 no.4
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• pp.36-44
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• 1999

기존의 미국 식품의약국(FDA, Food and Drug Administration)규정에 따르면 어떤 식품첨가물의 기능과 안정성을 평가하는 방법은 그때 그때 각각의 경우에 맞게 설정하여 실시하게 되어 있다. 이런 평가 방법은 포괄적이기는 하지만 과잉의 기능과 안정성 시험을 실시하는 결과를 초래해 왔다. 여기서는 새로운 식품 첨가물에 대한 안정성 시험 시 그 첨가물이 사용되는 실제 조건 하에서 체계적이고 과학적인 접근 방법에 따라 시험이 되도록 할 것을 제안하고자 한다. 체계적인 방법으로 시험하기 위해서는 새로 개발된 식품첨가물들이 사용하게 될 적용 대상 식품의 여러가지조건(pH, 수분, 가공 및 저장 온도)에서 그 첨가물의 안정성에 영향을 미치는 화학적, 물리적 주요 요인들이 먼저 결정되어야 한다. 그 다음 기능성과 안전성에 관련된 요소들이 하나의 모델 시스템으로 조직화되어 주요요인들의 측정 범위가 정해져야 한다. 마지막으로 설정된 모델 시스템은 첨가물이 실제 적용받게 되는 가공,운송, 저장 조건 하에서의 사용 조건을 고려한 상태에서 첨가물을 시험하여 기능과 안정성이 입증되어야 한다. 일단 증명이 되면 그 모델 시스템은 사용 가능성이 있는 적용 범위에까지도 그 첨가물의 기능성과 안정성을 평가할 수 있게 해준다. 이 논문에서는 식품첨가물 시험방법에 대한 체계적인 접근 방법을 설명하고 아스파탐의 예를 들어서 그 방법을 조명해 보고자 한다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.24 no.5
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• pp.375-393
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• 2022

This study was deal with blow-out and buoyancy stability evaluation method for slurry shield TBM. When applying a slurry shield TBM for the construction of a shallow tunnel under river or sea, the stability of slurry blow-out and segment lining buoyancy should be evaluated. However, there is a problem in that the currently applied theoretical formula is somewhat complicated, making it inconvenient to calculate in practice. In this study, some simple charts were proposed to easily evaluate the stability of slurry blow-out and segment lining buoyancy. In addition, the buoyancy safety factor of segment lining using the strength reduction method was evaluated and compared with the buoyancy safety factor based on the theoretical formula. The buoyancy safety factor by the theoretical formula was evaluated to be rather small, and it was confirmed that it was on the safe side. The simplified charts for the evaluation of slurry blow-out and buoyancy stability presented in this study are expected to be usefully utilized in the planning and design of undersea tunnels.