• 한국구조물진단유지관리공학회 논문집
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• 제14권1호
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• pp.84-92
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• 2010

본 논문은 지하공동의 굴착시 중요한 영향을 미치는 인자인 공동 규모와 절리 방향성이 지하공동의 거동에 미치는 영향을 파악하기 위해 연구를 실시하였다. 연구를 수행하기 위해 공동 규모와 절리 방향성에 따른 8가지 Case를 선정하여 수치해석을 실시하고 축소모형실험을 통해 검증하였다. 이를 통해 2가지 인자에 따른 응력양상을 정량적으로 평가하였다. 본 연구의 연구결과 공동 규모가 커질수록 천단부의 수직응력 및 좌 우측부의 수평응력은 증가하였다. 또한, 절리 방향성에 따른 공동의 응력양상은 절리면을 따라 미끄러짐이 발생하여 응력변화에 큰 영향을 미치는 것을 확인하였다. 이러한 결과에 따라 연구가 지하공동의 안정성 평가에 대해 유용한 정보를 제공할 것이다.

• Journal of Yeungnam Medical Science
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• 제31권2호
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• pp.117-121
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• 2014

Transarterial chemoembolization (TACE) is a widely accepted nonsurgical modality used for the treatment of multinodular hepatocellular carcinoma (HCC). The careful selection of the candidate is important due to the risk of developing various side effects. Fever, nausea, abdominal pain, and liver enzyme elevation are commonly known side effects of TACE. Hepatic failure, ischemic cholecystitis, and cerebral embolism are also reported, although their incidence might be low. Pulmonary complication after TACE is rare, and the reported cases of lipiodol pneumonitis are even rarer. A 53-year-old man was treated with TACE for ruptured HCC associated with hepatitis B virus infection. On day 19 after the procedure, the patient complained of dyspnea and dry cough. Chest computed tomography showed diffuse ground glass opacities in the whole-lung fields, suggesting lipiodol-induced pneumonitis. After 2 weeks of conservative management, the clinical symptoms and radiologic abnormalities improved. Reported herein is the aforementioned case of lipiodol-induced pnemonitis after TACE, with literature review.

• 한국약용작물학회지
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• 제17권3호
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• pp.204-209
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• 2009

This study was conducted to assess water movement in paddy-upland rotation soil scheduled for ginseng cultivation through the measurement of infiltration and permeability of soil water. Soil sample was divided with four soil layers. The first soil layer (to 30cm from top soil) was loamy sand, the second and the third soil layers (30$\sim$70 ㎝) were sand, and the fourth (< 120 ㎝) was sandy loam. The soil below 130 ㎝ of fourth soil layer was submerged under water. The shear strength, which represents the resisting power of soil against external force, was 3.1 kPa in the first soil layer. This corresponded to 1/8 of those of another soil layer and this value could result in soil erosion by small amount of rainfall. The rates of infiltration and permeability depending on soil layers were 39.86 cm $hr^{-1}$ in top soil, 2.34 cm $hr^{-1}$ in 30$\sim$70 ㎝ soil layer, 5.23 cm $hr^{-1}$ and 0.18 cm $hr^{-1}$ in 70$\sim$120 ㎝ soil layer, with drain tile, and without drain tile, respectively. We consider that ground water pooled in paddy soil and artificial formation of soil layer could interrupt water canal within soil and affect negatively on water movement. Therefore, we suggest that to drain at 5 m intervals be preferable when it makes soil dressing or soil accumulation to cultivate ginseng in paddy-upland rotation soil to reduce failure risk of ginseng cultivation.

• 비교문화연구
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• 제38권
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• pp.265-295
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• 2015

This article is concerned about a reason for which Cervantes participates an arabic author named Benengeli and morisco translator in his work instead of christian author. From the multi-cultural point of view, the time in which Don Qujote was published, belongs to the Golden Age. In other words, the society can not be supported by the ideology of Purity of Blood in that the morisco, converso (Christian Jewish) have been permitted to coexist in the name of christian proselyte or New Christian despite of invisible discrimination. An invisible discrimination is based on the prejudice and negative stereotype of Old Christian against the New Christian. Cervantes offers an o open space for readers to participate in the creative reading, giving up the absolute authority of author named Benengeli. The deep-rooted prejudice against morisco or muslim author makes the readers of Don Quijote do reinterpret the contents and have question about his sincerity. This disbelief is partly on the basis of hypothesis that Don Quijote would be passed on orally by an arabic or morisco. Leaving the hypothesis alone, Romance, festival performances of morisco or the aljamia literature in the Iberian Peninsula have the chivalry or knights of the Occident. The chivalry in Romance of morisco means that morisco would seek assimilation into the mainstream of Occidental Christian community. At the same time, morisco would be faced with the dilemma of loss of religious identity. But Taqiyya, islamic doctrine, offsets the dilemma between yearning to assimilate into mainstream and religious conscience of morisco in that Taqiyya permits morisco to convert to Christianity in case that they are in danger of life or the following risk. From this point of view, There is no room for doubt about the fact that Taqiyya contributed to social assimilation or multicultural society of the Iberian Peninsula. It has been a long time since a narrow-minded religious dogma and ideology became a anachronistic relic in multicultural society of Spain such as the Purity of Blood. From a relative viewpoint, Don Quijote provides a ground for the collective intelligence among christian, muslim(morisco) and converso through a liberal community between readers and authors who form a pluralistic society.

• 융합보안논문지
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• 제18권5_2호
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• pp.3-10
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• 2018

드론은 지상에서 전파를 사용하여 조종, 제어가 가능한 무인 항공기로 조종사가 탑승하지 않고 무인으로 움직인다. 무인항공기의 역사는 군사용에서 시작되었는데 1917년 미국에서 제작된 '스페리 에어리얼 토페도' 드론이 폭탄을 싣고 최초로 비행에 성공한 것이 첫 무인항공의 시작이었다. 무인항공 기술의 발달로 군사용 드론의 용도는 더욱 넓은 분야로 확대되었다. 최근 드론의 용도는 농업, 산업, 물류, 방송, 안전 등 다양한 분야에서 활용되고 있으며 그에 따른 시장의 규모도 점차 확대되고 있다. 드론은 우리의 실생활에 깊이 파고들어 없어서는 안 될 존재로 부각되고 있지만 사용자의 용도에 따라 나쁜 목적으로 사용될 수 있고 이로 인한 위험요소는 간과되고 있는 현실이다. 따라서 드론과 관련한 기술적인 결함과 조종자의 실수로 발생될 수 있는 사고까지 완벽하게 예방할 수 없지만 드론을 불법하게 사용하여 발생될 수 있는 사생활 침해, 보안 유출, 테러 등은 사전에 차단되어야만 드론산업 발전의 저해가 되지 않고 가속화를 가져올 것으로 본다.

• 한국안전학회지
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• 제36권5호
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• pp.10-17
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• 2021

The controversy over the risk of the human body being affected by electromagnetic fields emitted from 60 Hz power lines continues without end. There are currently no new studies or research progress being made in this direction that is notable, and the number of civil complaints is gradually increasing. The problem is that each study produces different results, among which the effect of exposure to magnetic fields on childhood leukemia is a major one. In Korea, an electrician who was maintaining a 22.9 kV power line died of leukemia, which has recently been recognized as an occupational disease. Methods to reduce magnetic fields from power lines include shielding with wire loops, incorporating split phases and compaction techniques, installing underground power lines, converting to high-voltage direct current (HVDC), and increasing the ground clearance of transmission towers. Depending on whether a separate power supply is needed or not, there are two types of wire loops: passive loop and active loop. Magnetic field reduction is currently done through underground power lines; however, the disadvantage of this process is high construction costs. Installing passive loops, with relatively low construction costs, leads to lower magnetic field reduction rates than installing underground cables and a weakness to not solving the landscape problem. This methodological study aims at designing methods and reducing the effects of 2-wire set loops-the simplest and most practical. Since the method proposed in this study has been designed after analyzing the distribution of complex electromagnetic fields near the expected loop installation location, a practical design can be implemented without the need for any difficult optimization programming.

• Structural Engineering and Mechanics
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• 제68권6호
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• pp.747-760
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• 2018

In the present study, a methodology for developing fragilities of arch concrete dams to assess their performance against seismic hazards is introduced. Firstly, the probability risk and fragility curves are presented, followed by implementation and representation of the way this method is used. Amirkabir arch concrete dam was subjected to non-linear dynamic analyses. A modified three dimensional rotating smeared crack model was used to take the nonlinear behavior of mass concrete into account. The proposed model considers major characteristics of mass concrete. These characteristics are pre-softening behavior, softening initiation criteria, fracture energy conservation, suitable damping mechanism and strain rate effect. In the present analysis, complete fluid-structure interaction is included to account for appropriate fluid compressibility and absorptive reservoir boundary conditions. In this study, the Amirkabir arch concrete dam is subjected to a set of 8 three-component earthquakes each scaled to 10 increasing intensity levels. Using proposed nonlinear smeared crack model, nonlinear analysis is performed where the structure is subjected to a large set of scaled and un-scaled ground motions and the maximum responses are extracted for each one and plotted. Based on the results, fragility curves were plotted according to various and possible damages indexes. Discrete damage probabilities were calculated using statistical methods for each considered performance level and incremental nonlinear analysis. Then, fragility curves were constructed based on the lognormal distribution assumption. Two damage indexes were introduced and compared to one another. The results indicate that the dam has a proper stability under earthquake conditions at MCE level. Moreover, displacement damages index is more conservative and impractical in the fragility analysis than tensional damage index.

• 대한안전경영과학회지
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• 제21권2호
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• pp.9-14
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• 2019

Gondola is widely used as a construction facility to perform external finishing work without using scaffolding at a construction site. However, since 2000, there have been 17 deaths from now so these risks associated with work can not be ignored. Therefore, it is expected that it will contribute greatly to prevent related disasters if introducing necessary measures to prevent repeated related disasters and installing additional safety devices. In order to eliminate the risk factor according to the operation of the gondola, it is necessary for the operator to use it to use it while the examination of each product is completed, and to use the over load Dangerous arbitrary measures such as arbitrary operation of the prevention device, removal of the safety fence for convenience of work, installation of the wire rope installed in the air, falling out of the wire rope and falling to the ground Do not perform such sealing measures so that any operation of the overload prevention device can not be done so as not to take such arbitrary measures, or wire the power supply wire to the safety fence so as not to delete the safety fence. Then, when the safety fence is removed, so that it does not become a gondola operation, or when replacing the wire rope in the air, to prevent the wire rope from coming off, Additional measures such as installing falling down prevention device may be necessary.

• Earthquakes and Structures
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• 제16권6호
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• pp.715-726
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• 2019

Several municipal seismic vulnerability investigations have been identified pounding of adjacent structures as one of the main hazards due to the constrained separation distance between adjacent buildings. Consequently, an assessment of the seismic pounding risk of buildings is superficial in future adjustment of design code provisions for buildings. The seismic lateral oscillation of adjacent buildings with eccentric alignment is partly restrained, and therefore a torsional response demand is induced in the building under earthquake excitation due to eccentric pounding. In this paper, the influence of the eccentric seismic pounding on the design demands for adjacent symmetric buildings with eccentric alignment is presented. A mathematical simulation is formulated to evaluate the eccentric pounding effects on the seismic design demands of adjacent buildings, where the seismic response analysis of adjacent buildings in series during collisions is investigated for various design parameters that include number of stories; in-plan alignment configurations, and then compared with that for no-pounding case. According to the herein outcomes, the effects of seismic pounding severity is mainly depending on characteristics of vibrations of the adjacent buildings and on the characteristics of input ground motions as well. The position of the building wherever exterior or interior alignment also, influences the seismic pounding severity as the effect of exposed direction from one or two sides. The response of acceleration and the shear force demands appear to be greater in case of adjacent buildings as seismic pounding at different levels of stories, than that in case of no-pounding buildings. The results confirm that torsional oscillations due to eccentric pounding play a significant role in the overall pounding-involved response of symmetric buildings under earthquake excitation due to horizontal eccentric alignment.

• 한국군사과학기술학회지
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• 제24권1호
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• pp.50-60
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• 2021

For conventional AESA radars, DC-DC power modules using 300 Vdc have low efficiency, high volume, heavy weight, and high price, which have problems in modularity with T/R module groups. In this paper, to improve these problems, we propose a distributed DC-DC power module with high-voltage 800 Vdc and high-efficiency Step-down Converter. In particular, power requirements for modern and future marine weapons systems and sensors are rapidly evolving into high-energy and high-voltage power systems. The power distribution of the next generation Navy AESA radar antenna is under development with 1000 Vdc. In this paper, the proposed highvoltage, high-efficiency DC-DC power modules increase space(size), weight, power and cooling(SWaP-C) margins, reduce integration costs/risk, and reduce maintenance costs. Reduced system weight and higher reliability are achieved in navy and ground AESA systems. In addition, the proposed architecture will be easier to scale with larger shipboard radars and applicable to other platforms.