• Journal of the Computational Structural Engineering Institute of Korea
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• v.30 no.3
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• pp.191-198
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• 2017

To study the behavior of structures subject to blast loads it is important to calculate the loads due to the explosives accurately, especially in the case of interior explosions. It is known that numerical method based on computational fluid dynamics can estimate relatively accurate blast load due to the interior explosion including reflection effect. However, the numerical method has disadvantages that it is difficult to model the analysis and it takes much time to analyze it. Therefore, in this study, the analytical method which can include the reflection effect of the interior explosion was studied. The target structures were set as the slabs of residential buildings subject to interior explosion that could lead to massive casualties and progressive collapses. First, the numerical method is used to investigate the interior explosion effect and the maximum deflection of the slab which was assumed to be elastic, and compared with the analytical method proposed in this study. In the proposed analytical method, we determine the weighting factor of the reflection effect using the beam theory so that the explosion load calculation method becomes more accurate.

• Journal of Sasang Constitutional Medicine
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• v.16 no.2
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• pp.44-51
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• 2004

1. Objectives This paper is written for clear understanding on the concepts of 'Deep adherence of the Nature' and 'Sudden explosion of the Emotion' and for intensive comprehension of Mechanism of 'The Exterior Disease' and 'The Interior Disease' by The Nature and the Emotion. 2. Methods The study mainly based on "The exterior disease injured by the Nature, the interior disease injured by the Emotion" and deals with 'Seongmyungron, Sadanron, Hwarkchungron and Jangburon'. 3. Results and conclusions The conclusions as follows (1) Exterior Disease in each constitution breaks out by deep adherence of the Nature. Interior Disease brings out with sudden explosion of the Emotion. (2) 'Deep adherence of the Nature' is the state that the Ear, Eye, Nose, Mouth taking care of environmental frames can't work enoughly because of wrong minds on the Jaw, Breast, Umbilicus, Abdment. 'Sudden explosion of the Emotion' is the state that the Lung, Spleen, Liver, Kidney doing human affairs doesn't do appropriately for each constitution due to negative minds on the Head, Shoulder, Waist, Hip. (3) The result that the Ear, Eye, Nose, Mouth doesn't extract the clear energy from 'Jin, Go, You, Yaek sea' so they are lack of 'Shin, Qi, Hyul, Jeong' causes exterior disease in each constitution. (4) In each constitution, Interior disease results from that the Lung, Spleen, Liver, Kidney fails to bring on the clear juice from 'Lee, Mak, Hyul, Jeong sea', so shortage of 'Jin, go, You, Yaek' results in it.

• Structural Engineering and Mechanics
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• v.38 no.5
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• pp.633-649
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• 2011

The paper presents a study aimed at understanding some characteristics of an interior explosion within a room with limited or no venting. The explosion may occur in ammunition storage or result from a terrorist action or from a warhead that had penetrated into this room. The study includes numerical simulations of the problem and analytical derivations. Different types of analysis (1-D, 2-D and 3-D analysis) were performed for a room with rigid walls and the results were analyzed. For the 3D problem the effect of the charge size and its location within the room was investigated and a new insight regarding the pressure distribution on the interior wall as function of these parameters has been gained. The numerical analyses were carried out using the Eulerian multi-material approach. Further, an approximate analytical formula to predict the residual internal pressure was developed. The formula is based on the conservation law of total energy and its implementation yields very good agreement with the results obtained numerically using the complete statement of the problem for a wide range of explosive weights and room sizes that is expressed through a non-dimensional parameter. This new formula is superior to existing literature recommendations and compares considerably better with the above numerical results.

• Explosives and Blasting
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• v.35 no.3
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• pp.21-30
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• 2017

When explosives explode in water, the effect of post-explosion gas after explosion should be considered, unlike explosion in the air. During explosion in water, the propagation velocity of the explosion pressure is faster than when the explosion occurs in the air. The generated gas is diffused and trapped in the form of bubbles by water before the energy is dissipated. At this time, the bubble expands and contracts, creating a shock wave. In order to investigate this series of phenomena, a cylinder type steel water tank capable of observing the interior was fabricated and explosion experiments were conducted. In this study, a small amount of shell-free pentolite was exploded in water. Experiments were performed to observe the behavior of the generated gas bubble as well as to measure the shock wave generated. We designed the experimental method of underwater explosion and examined the results.

• Journal of the Korean Society of Safety
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• v.37 no.4
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• pp.92-100
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• 2022

Of the Korean military's 3,959 ammunition depots, 1,007 - more than 25% - violate safety requirements for distance and equipment. There is a risk of explosion in old depots that are vulnerable to various interior and exterior accidents. This paper examines 10 scenarios, with varying values for ammunition amount and safety distance. The study calculated the overpressure that can be applied to risk-exposure objects, based on the safety distance; expected damage was predicted using constructed spatial information from 3D explosion simulations. The simulations confirmed that explosion overpressure increased the most when the safety distance violation rate increased from 80% to 90%. It also confirmed that secondary damage such as fire and explosion can cause casualties and property damage when the violation rate is 60% or higher. The results show that building collapse becomes a risk with a violation rate of 70% or higher. We conclude that taking ammunition depot safety distance violation into account when planning military facilities and their land utilization could better protect life and property.

• Journal of the Korean Wood Science and Technology
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• v.41 no.2
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• pp.111-122
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• 2013

The steam explosion-chemical pretreatment is a more effective wood pretreatment technique than the conventional physical pretreatment by accelerating reactions during the pretreatment process. In this paper, two-stage pretreatment processes of hardwood were investigated for its enzymatic hydrolysis and the succinic acid yield from the pretreated solid. The first stage pretreatment was performed under conditions of low severity to optimize the amount of solid recovery. In the second stage pretreatment washed solid material from the first stage pretreatment step was impregnated again with chemical (alkaline or chlorine-based chemicals) to remove a portion of the lignin, and to make the cellulose more accessible to enzymatic attack. The effects of pretreatment were assessed by enzymatic hydrolysis and fermentation, after the two stage pretreatments. Maximum succinic acid yield (16.1 g $L^{-1}$ and 77.5%) was obtained when the two stage pretreatments were performed at steam explosion -3% KOH.

• Journal of the Korean Wood Science and Technology
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• v.44 no.2
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• pp.241-252
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• 2016

Cellulose acetate is one of well-known industrial materials which have various commercial uses. We treated the lignocellulosic biomass using two-step (steam explosion-chemical) reaction followed by acetylation to get the cellulose acetate in this study. The two-step treatment was done to improve the yields of acetylation of the substrates. The yields of the cellulose acetate were about 88.4, 88.1, and 151.7% in barley straw, rice straw, and oak tree, respectively. Also the degree of substitution (DS) of the acetates was 2.1 to 2.5 in the biomass. We found that the biomass were valuable cellulosic sources, including their derivatives, in this study. This means that the biomass can be converted into the high-valued cellulosic stuff.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.481-483
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• 2015

Multi-dimensionality in the inner working of core-collapse supernovae has long been considered one of the most important ingredients to understand the explosion mechanism. We perform a series of numerical experiments to explore how rotation impacts the 3-dimensional hydrodynamics of core-collapse supernova. We employ a light-bulb scheme to trigger explosions and a three-species neutrino leakage scheme to treat deleptonization effects and neutrino losses from the neutron star interior. We find that the rotation can help the onset of neutrino-driven explosions for models in which the initial angular momentum is matched to that obtained from recent stellar evolutionary calculations (${\sim}0.3-3rad\;s^{-1}$ at the center). For models with larger initial angular momenta, a shock surface deforms to be oblate due to larger centrifugal force. This makes a gain region, in which matter gains energy from neutrinos, more concentrated around the equatorial plane. As a result, the preferred direction of the explosion in 3-dimensional rotating models is perpendicular to the spin axis, which is in sharp contrast to the polar explosions around the axis that are often obtained from 2-dimensional simulations.

• Korean Institute of Interior Design Journal
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• v.24 no.1
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• pp.152-159
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• 2015

Contemporary architecture is philosophy and art, and science are different that holds the architecture of human thought and behavior based on a variety of physical space. In addition, the technology is used by the new media graphics, lasers, LED, which were possible only in imagination, using tools such as the time-space of the potential for explosion. In particular, it was found in the spacial color of atypical using the nature of light. Such these architecture is space people actively experiencing a sense towards the expansion of its place. Therefore, the study purpose is to explore the Steven Holl's spacial colors to utilize the space is important to the possibility of light. He prefers the connection to the invisible world is inferred from the visible world and other space. He thoughts an idea linked to the concept watercolors which is a tool that holds to the notion of the flexibility of light and shadow. Concept watercolor is the idea space, establish space, recombinant space, and the growthy space. These have shown the no fixed spacial color cause of the combination of the different tones according to the characteristics of the mixed-color development of a concept watercolors demonstrated the spacial color of the replacement. That is to establish a parody of the works light blending spacial color.

• Journal of The Korean Digital Architecture Interior Association
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• v.9 no.3
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• pp.85-93
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• 2009

In this study, the ex-formal expressions observed in space form of Korean modern architecture are distributed for characteristic analysis based on the period and type. The result of the study is certified by the work analysis and the result is as follows. Initially, due to the limited materials and influence of western brutalism, the works developed during 1960~70 tend to be plastic and contain expressionism. Around 1980's, the works tend to show forms of amusement and popularity. In 1990's the works show significance in deconstructive expression. From after 2000, ecological concept of architecture was introduced and organic expression started increasing Secondly, the ex-formal expressions are found to be in four different types. The organic expression is shown regardless of the period. In modern days, not only the physical properties of materials, but also the ecological concept is combined with the organic expression and is in increase. The plural expression started appearing after the 1980's and the sculptural diversity is enhancing with the addition of decorative factors or modification of geometrical form. The ex-construction and deconstructive expression show significance in some characteristics such as folding, inclination, and geometrical explosion. The free form and nonlinear expression tend to increase dramatically based on the development of structure technology as well as execution and introduce of the digital design technique.