• Title/Summary/Keyword: damage path

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Collapse Simulations of High-Rise RC Building Using ELS Software and Application of Explosive Demolition Methods to Transition Process Analysis from Local Damage to Progressive Collapse (ELS를 이용한 고층 RC 빌딩의 붕괴해석 및 발파해체해석 기법의 국부손상-연쇄붕괴 전이과정 해석에 응용)

  • Kim, Hyon-Soo;Park, Hoon;Kim, Seung-Kon;Lee, Yeon-Gyu;Cho, Sang-Ho
    • Explosives and Blasting
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    • v.29 no.2
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    • pp.1-12
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    • 2011
  • Progressive collapse analyses of high-rise buildings subjected to abnormal loading such as fires, impacts, earthquakes, typhoon, bomb blasts etc. are intended. However it is difficult to perform collapse experiments of the real scale building to determine the capacity of the structure under an extreme loading events. In this study, collapse behavior of a 15 story RC structure building loaded by external explosion pressures were simulated using Extreme Loading Structures (ELS) software. The standoff distance between the RC building and explosives of 1500 kg was 1, 2, 5, 10, and 15 meters. The explosive demolition analysis techniques based on removal of partial support structures following blast scenario was adapted to investigate the transition process of progressive collapse-local damage.

Evacuation Simulation of High-Rise Building Fires Considering Temperature and Smoke (열화와 연기를 고려한 고층 건물 화재시의 대피 시뮬레이션)

  • Lee, Bum-Jong;Park, Jong-Seung;Rie, Dong-Ho
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.703-707
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    • 2008
  • This paper proposes a method of design and implementation a simulation system in which humans can plan their evacuation paths in a high-rise building considering damages from high temperature and smoke in case of fire. Humans in evacuation search the nearest exit and follow a path to the exit. When humans are evacuating toward an exit, they are going to move with their highest speeds. However, many environmental factors prohibit their fast movements. In this paper, we calculate the evacuation speed of each human considering temperature damage and smoke damage. We restrict the number of humans that can be evacuated per second according to the actual size of the exit door. Experimental results showed that the evacuation speed is affected by the temperature condition and the smoke density.

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Effective Motor Evoked Potential Waveforms in Patients with Lower Extremity Weakness (다리에 힘이 없는 환자에서 효과적인 운동 유발전위 파형 측정에 대한 고찰)

  • Lim, Sung-Hyuk;Park, Sang-Ku;Han, Hung-Tae
    • Korean Journal of Clinical Laboratory Science
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    • v.48 no.1
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    • pp.41-48
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    • 2016
  • Motor evoked potential of spinal surgery is known to cause damage due to the movement path of the continuous scan operation and surgery can be performed with minimized disability after surgery. However, if it is not at all formed at the wave motion evoked potential can occur during surgery and, in some cases the size of the waveform to be measured is very small and intermittent. In this case, the surgery cannot provide information about whether there is neurological damage. Increased intensity of the wave-induced motion of the dislocation does not occur if it appears in a very small amplitude stimulus, but changing the inspection area that electrical stimulation of the waveform changes could not be found. However, stimulation of a wide area in the cerebral cortex was found to occur with a waveform in the patients who underwent examination. Through this study, we propose a useful motor evoked potential test. From November to December 2015 three spine surgery patients visited Samsung Medical Center as neurosurgery patients with omission discomfort, gait disturbance, and no symptom of strength before surgery. In spine surgery patients with motor grade weakness, when motor evoked potential waveform has not been measured, in examination of the site of electrical stimulation of the cerebral cortex from entering the C3+C5/C4+C6 or C3+C1/C4+C2 if by the activity of more motor neuron unit, it was found that the waveform is better formed.

Analysis of Erosion in Debris Flow Experiment Using Terrestrial LiDAR (지상 LiDAR를 이용한 토석류 실험의 침식량 분석)

  • Won, Sangyeon;Lee, Seung Woo;Paik, Joongcheol;Yune, Chan-Young;Kim, Gihong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.3
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    • pp.309-317
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    • 2016
  • Debris flows are rapidly flowing masses of water mixed with soil and gravel from landslides which are caused by typhoons or rainstorms. The combination of Korea’s mountain dominated topography (70%) and seasonal heavy rains and typhoons causes landslides and large-scale debris flows from June to August. These phenomena often cause property damage and casualties that amount up to 20% of total annual disaster fatalities. The key point to predicting debris flow is to understand its movement mechanism, erosion, and deposition. In order to achieve a more accurate estimation of debris flow path and damage, this study incorporates quantitative analysis of high resolution LiDAR DEM (GSD 10cm) to delineate geomorphic and topographic changes induced by Jinbu real scale debris flow test.

NEUROTOXICITY OF TRIMETHYLTIN IN HIPPOCAMPUS: A HYPEREXCITATORY TOXICITY

  • Chang, Louis W.
    • Toxicological Research
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    • v.6 no.2
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    • pp.191-204
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    • 1990
  • Trimethyltin (TMT) induced lesions in the rat hippocampal formation was reviewed. Adult rats were treated with a single dose of 6.0 mg TMT/kg b.w. and were sacrificed between 3-60 days following exposure. On the hippocampal formation, the granule cells of fascia dentata showed early changes which subsided considerably at a later time when the destruction of the pyramidal neurons of the Ammon's horn became increasingly pronounced with time, leading to severe destruction of the structure. It is interesting to note that there was an inverse relationship of pathological involvement between the f.d. granule cells and the Ammon's horn neurons; i.e., when there was a large sparing of the granule cells. there was an extensive damage to the Ammon's horn and vice versa. This inverse relationship was also true between the $CA_3$neurons and the $CA_{1,2}$neurons in the Ammon's horn. Progressive zinc loss, as demonstrated by Timm's method, on the Mossy fibers was also observed. Similar Mossy fiber zinc depletion has been demonstrated in electrical stimulatory excitation condition of the perforant path to the hippocampus. Depletion of corticosterone, an inhibitor to the hippocampal neurons, by means of adrenalectomy will exaggerate the TMT induced hippocampal lesion. Neonatal study revealed that a unique degenerative pattern of the Ammon's horn could be established in accordance with exposure to TMT at specific maturation periods of the fippocampal formation: increasing destruction of the Ammon's horn with increasing synaptogenesis between the f.d. granule cells and the Ammon's horn neurons. Thus it is apparent that the damage of the Ammon's horn, upon exposure to TMT, may depend on the integrity and functional state of the f.d. granule cells. A hyperexcitory scheme and mechanism as the toxicity basis of TMT in the hippocampal formation is proposed and discussed.

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Study on Dangerous Factors and Damage Pattern Analysis of Leaking Water from Water Purifiers (누수가 발생한 정수기의 위험요소 발굴 및 소손패턴 해석에 관한 연구)

  • Choi, Chung-Seog
    • Journal of the Korean Society of Safety
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    • v.27 no.3
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    • pp.57-62
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    • 2012
  • The purpose of this paper is to find dangerous factors of a water purifier when water leaks due to inappropriate use and analyze the patterns of damaged parts in order to provide data for the examination of the cause of the problem. If the water purifier is inspected and managed by a non-specialist, when the FLC(Float Level Controller) at the top is inclined, water leakage may occur to the water purifier. The leaked water flows onto the cables and hoses and enters the thermostat terminal, heater, PCB, power supply connection connector, etc., becoming a dangerous factor that may cause a system failure, fire, etc. Due to the water that entered the input terminal, low noise and white smoke were generated at first. However, the flame gradually propagated due to the continuous inflow of moisture. It was found that when moisture reached the PCB, a carbonized conductive path was formed at the varistor terminal, input terminal, semiconductor device terminal, etc., and the flame became larger, which might result in a fire. From the metal microscope analysis of a damaged condenser terminal, it was found that the amorphous structure unique to copper cable disappeared, and voids, boundary surface and disorderly fine particles occurred. Also, in the case of the connector into which moisture penetrated, fusion and deformation occurred at the cable connection clips. The result of analysis of the power supply cable connector using a thermal image camera showed that most of the heat was generated from the cable connection clips and the temperature at the connection center was normal.

Experimental Study of Strength and Ductility on Masonry Wall Frame and Shear Wall Frame Subjected to Cyclic Lateral Loading (반복-횡력을 받는 조적벽 골조와 전단벽 골조의 내력 및 연성에 관한 실험적 연구)

  • Lee, Ho;Byeon, Sang-Min;Jung, Hwan-Mok;Lee, Taick-Oun
    • Journal of Korean Association for Spatial Structures
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    • v.13 no.2
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    • pp.83-91
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    • 2013
  • The core aim of this dissertation is to empirically scrutinize a strength characteristic of beam-column frame subjected to the cyclic lateral load, a beam-column frame of un-reinforced masonry wall, and a shear wall frame. First and foremost, I embark upon making three prototypes vis-$\grave{a}$-vis this research. By conducting this process, I touch on an analysis of cyclic behavior and a damage characteristic of the beam-column frame, the beam-column frame of un-reinforced masonry wall, and the shear wall frame. What is more, through the previous procedure, the next part delves into the exact stress transfer path and the destructive mechanism to examine how much and how strong the beam-column frame of un-reinforced Masonry Wall does have a resistance capacity against earthquake in all the architecture constructed by the above-mentioned frame, as well as school buildings. In addition to the three prototypes, two more experimental models, a beam-column frame and shear wall frame, are used to compare with the beam-column frame of un-reinforced masonry wall. Lastly, the dissertation will suggest some solutions to improve the resistance capacity against earthquake regarding all constructions built with non bearing wall following having examining precisely all the analysis with regard to not only behavior properties and the damage mechanism of the beam-column frame and the beam-column frame of un-reinforced Masonry Wall but also the resistance capacity against earthquake of non bearing wall and school buildings.

Pathological Entity of Jueyin Disease and the Relationship between the Concept of Three-Yin-Three-Yang in 《Shanghanlun》 (《상한론(傷寒論)》 궐음병의 병리본질과 삼음삼양(三陰三陽) 개념과의 관계)

  • Chi, Gyoo Yong;Park, Shin Hyung
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.33 no.2
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    • pp.75-81
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    • 2019
  • In order to research the pathological entity of Jueyin disease in ${\ll}Shanghanlun{\gg}$, some sharing concept of three-yin-three-yang used in ${\ll}Neijing{\gg}$ and ${\ll}Shanghanlun{\gg}$ were investigated first, and then the meaning of jueyin and jueyin disease were analyzed. In cold damage disease, time-space factor is important because the pathological change is rapid and the symptoms along path are similar, therefore three-yin-three-yang having complex meaning of time and space can be used as an appropriate pathological concept. So to speak, it is able to be interpreted as various modes like variations of yin-yang, qi-blood, change of pulse condition, theories of opening, closing, pivot or exuberance and debilitation of form and qi manifested in the six districts of the human body following disease process. Jueyin is between front taiyin and rear shaoyin, and it's attribution is inherent in qi stagnation and yin exuberance in relative to the location of flank and liver. Putting together above descriptions, pathological entity of jueyin disease is that the symptoms mingled with cold and stagnant heat competing each other when a subject having qi stagnation in flank with cold in extremities and lower abdomen in particular is seized with cold influenza.

Behaviour insights on damage-control composite beam-to-beam connections with replaceable elements

  • Xiuzhang He;Michael C.H. Yam;Ke Ke;Xuhong Zhou;Huanyang Zhang;Zi Gu
    • Steel and Composite Structures
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    • v.46 no.6
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    • pp.773-791
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    • 2023
  • Connections with damage concentrated to pre-selected components can enhance seismic resilience for moment resisting frames. These pre-selected components always yield early to dissipate energy, and their energy dissipation mechanisms vary from one to another, depending on their position in the connection, geometry configuration details, and mechanical characteristics. This paper presents behaviour insights on two types of beam-to-beam connections that the angles were designed as energy dissipation components, through the results of experimental study and finite element analysis. Firstly, an experimental programme was reviewed, and key responses concerning the working mechanism of the connections were presented, including strain distribution at the critical section, section force responses of essential components, and initial stiffness of test specimens. Subsequently, finite element models of three specimens were established to further interpret their behaviour and response that were not observable in the tests. The moment and shear force transfer paths of the composite connections were clarified through the test results and finite element analysis. It was observed that the bending moment is mainly resisted by axial forces from the components, and the dominant axial force is from the bottom angles; the shear force at the critical section is primarily taken by the slab and the components near the top flange. Lastly, based on the insights on the load transfer path of the composite connections, preliminary design recommendations are proposed. In particular, a resistance requirement, quantified by a moment capacity ratio, was placed on the connections. Design models and equations were also developed for predicting the yield moment resistance and the shear resistance of the connections. A flexible beam model was proposed to quantify the shear resistance of essential components.

A Study on the Progress of Pig Butchering Crimes Using Cryptocurrency (암호화폐를 이용한 "돼지도살(Pig Butchering)" 사기범죄 진행과정에 대한 연구)

  • HyeJin Song
    • Journal of the Society of Disaster Information
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    • v.20 no.3
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    • pp.663-671
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    • 2024
  • Purpose: The purpose of this study is to examine the risks and criminal progress of pig murder fraud crimes in the absence of related research and statistics amid a surge in pig murder fraud damage in Korea, and to approach the methods, problems, and countermeasures that can be prevented in Korea through foreign cases. Method: In order to classify the types of pig murder fraud crimes, the progress was analyzed through related reports and statistics, and various damage cases. Result: The crime of pig murder fraud can be seen as an organized crime that organically combines simple romance scams, investment fraud, and human trafficking. In the case of victims, unlike simple fraud, psychological problems such as suicide impulse and panic disorder were found, and in the case of cryptocurrency acquired through fraud, a path was found to flow back into the criminal organization through money laundering. Conclusion: In the case of pig murder fraud crimes that have been detected as a danger worldwide, the scale will be even wider. Therefore, various institutional supplements and policies should be prepared through crime type analysis in Korea for crime prevention and countermeasures.