• 한국안전학회지
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• 제37권4호
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• pp.101-112
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• 2022

Expanding urbanization practices result in high numbers of buildings being developed in city centers. This high building concentration leads to an increased fire risk, resulting in higher casualty rates and increased economic damages compared to fires in the past. The purpose of this study was to analyze the structural behavior of fire-damaged reinforced concrete buildings using analytical methods and to suggest methods of improving fire resistance in the event of a fire. Damage levels were measured using commercial software to apply the finite element method, ABAQUS, and MIDAS GEN to the dataset. Load-deflection curves were calculated using the effective area and moment of inertia of the fire-damaged columns provided by ABAQUS. The results of this analysis indicate that fire-damaged beams with experience greater deflection from indoor fires than they will from outdoor fires. Fires that occurred on the middle floors were more dangerous than those occurring on higher floors, and eccentrically loaded columns experienced more damage than axially loaded columns. The results indicate that these methods accurately predict structural behaviors of fire damaged concrete columns by considering fire exposure area and eccentric loading.

• 한국조경학회지
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• 제37권3호
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• pp.113-124
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• 2009

본 연구는 교보생명빌딩 그린하우스를 대상으로 광조건에 따른 수목피해 및 생육상태 영향을 조사 분석하여 실내식물의 적절한 생육환경을 유지할 수 있는 적정 조도기준 도출을 목적으로 하였다. 광조건에 따른 조도현황과 고사목 교체주수, 수목피해율을 분석하여 생육조건에 따른 문제점을 파악하고 적정 조도기준을 도출하였다. 조도조사 결과 남측 음지와 양지에서 각각 531lux, 602lux로 가장 낮은 차이를 보인 반면에, 중앙 음지와 양지에서 210lux, 782lux로 약 500lux의 가장 높은 차이가 발생하였다. $1990{\sim}2004$년간 수목고사 조사결과 식재된 수목 중 아왜나무가 161주로 교체율이 가장 높았으며, 대나무 69주, 동백나무 40주, 후피향나무 40주 등의 순으로 조사되었다. 수목피해도 결과는 수종에 관계없이 채광이 양호한 양지구역에서는 평균 수목피해율이 $4.4{\sim}6.4%$로 경미하였으며, 음지구역에서는 수목피해율이 $21.9{\sim}48.8%$로 심각한 피해현상이 나타났다. 조도를 독립변수로, 수목피해도를 종속변수로 상관분석과 회귀분석을 각각 실시한 결과, 조도가 낮아질수록 수목피해율은 증가하였다. 조도가 $500{\sim}600lux$ 사이에서 피해율이 급격히 감소하였으며, 700lux 수준에서 피해율이 최소화되었다. 따라서 실내식물의 광조건에 의한 피해율을 줄이기 위해서는 최소 700lux이상의 조도가 필요한 것으로 판단되었다.

• 한국항공우주학회지
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• 제40권7호
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• pp.555-563
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• 2012

지구궤도 상에는 무수히 많은 우주파편(Orbital debris)이 존재하며 매우 높은 속도로 선회하고 있기 때문에 정상가동중인 인공위성과 충돌 시 위성구조체에 치명적인 손상을 일으킬 수 있다. 본 연구에서는 입자완화유체동역학(Smoothed particle hydrodynamics, SPH)을 이용하여 우주파편과의 초고속충돌로 인해 발생 가능한 저궤도 위성구조체의 손상분석을 수행하였다. 위성구조체의 본체 패널(Panel)로 사용되는 허니콤샌드위치패널(Honeycomb sandwich panel, HC/SP)에 대해 충돌속도에 따른 손상분석을 수행하였으며 위성구조체 내부부품의 안전성 분석을 위해 전자박스가 HC/SP에 직접 부착된 경우와 10cm 오프셋 된 경우에 대한 초고속충돌해석 및 손상분석을 수행하였다. 고도 685km의 저궤도에서 2% 정도의 충돌확률을 갖는 우주파편들을 고려할 때, HC/SP 자체에 관통이 발생하는 것으로 나타났으며 부착형 전자박스의 경우와 오프셋형 전자박스의 경우에는 전자박스에 관통이 발생하지 않고 미소 크레이터(Crater)만 발생되는 것으로 나타났다.

• 대한본초학회지
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• 제34권1호
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• pp.43-50
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• 2019

Objectives : The purpose of this study was to proofread 'one ryang' in the Decoction of ${\ll}$Treatise on Cold Damage Diseases${\gg}$. Methods : I found out the ratio of maximum dose and minimum dose in this book. On the basis of the ratio, I corrected 'one ryang' in diverse decoctions. Results : In any decoction, maximum dose of medicinal medica in one decoction could not exceed four times minimum dose. Specifically, in the case that maximum dose in one decoction is sixteen ryang, it could not exceed eight times minimum dose in the same decoction. Any medicinal medica used in two decoctions or more, its maximum dose could not exceed four times minimum dose in other decoctions. On the basis of these results, it should be changed into three ryangs that are one ryang dose of 'Haematitum' of Seonbokdaeja Tang, 'Ginger' of Bujageongang Tang, Baektong Tang, Baektonggajeodamjep Tang and Senggangsasim Tang. Furthermore it should be changed into two ryangs that are one ryang dose of 'Coptidis Rhizoma' of Sohamhyung Tang, 'Ginger' of Dowha Tang, 'Ginseng Radix' of Whubaksenggangbanhagamchoinsam Tang, 'Polyporus, Poria Sclerotium, Alismatis Rhizoma, Talcum and Asini Corii Colla' of Jeoryeong Tang, 'Cimicifugae Rhizoma, Atractylodis Rhizoma Alba and Anemarrhenae Rhizoma' of Mahuangshengma Tang and 'Cassiae Cortex Interior' of Gyejigamchoryonggolmoryeo Tang. Conclusions : These results suggest that one ryang of thirteen medicinal medica such as Haematitum or Ginger of eleven decoctions such as Seonbokdaeja Tang or Bujageongang Tang should be changed into two or three ryangs.

• Structural Engineering and Mechanics
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• 제86권3호
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• pp.385-397
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• 2023

This study presents an experiment and analysis to compare the seismic behavior of full-scale reinforced concrete beam-column joint strengthened by prestressed steel strips, externally bonded steel plate, and CFRP sheets. For experimental investigation, five specimens, including one joint without any retrofitting, one joint retrofitted by externally bonded steel plate, one joint retrofitted by CFRP sheets, and two joints retrofitted by prestressed steel strips, were tested under cyclic-reserve loading. The failure mode, strain response, shear deformation, hysteresis behavior, energy dissipation capacity, stiffness degradation and damage indexes of all specimens were analyzed according to experimental study. It was found that prestressed steel strips, steel plate and CFRP sheets improved shear resistance, energy dissipation capacity, stiffness degradation behavior and reduced the shear deformation of the joint core area, as well as changed the failure pattern of the specimen, which led to the failure mode changed from the combination of flexural failure of beams and shear failure of joints core to the flexural failure of beams. In addition, the beam-column joint retrofitted by steel plate exhibited a high bearing capacity, energy consumption capacity and low damage index compared with the joint strengthened by prestressed steel strip, and the prestressed steel strips reinforced joint showed a high strength, energy dissipation capacity and low shear deformation, stirrups strains and damage index compared to the CFRP reinforced joint, which indicated that the frame joints strengthened with steel plate exhibited the most excellent seismic behavior, followed by the prestressed steel strips.

• 사상체질의학회지
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• 제23권3호
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• pp.275-284
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• 2011

1. Objective: This literary review investigates Lee Jema's clinical experiences with Soyang-type patients and their influence on his conceptualization of the Soyang physiology and pathology. 2. Methods: 1) The case reports in "Soyang constitutional type: Spleen Cold-based Exterior-Cold disease" were compared before and after the Sinchuk revision to explore the temporal change in the Sasang medical concepts. 2) The texts in Donguisusebowon (Gabo edition) and Donguisusebowon (Sasangchobongwon) were analyzed to investigate the pathological concepts appearing before the completion of the Donguisusebowon (Gabo edition). 3) The texts in Donguisusebowon (Sinchuk edition) was analyzed to investigate the pathological concepts formed between the Gabo and Sinchuk editions of Donguisusebowon. 3. Results and Conclusions: 1) Gabo edition : The Gabo edition divided the External-origin Exterior disease into Cold-dominant (Heat-moderate) and Heat-dominant (Cold-moderate) patterns and differentiated the severity of Exterior-based Exterior disease and Interior-based Interior disease into mild, moderate, severe, and critical conditions. Cold-damage Delirium disease pattern was categorized as an Interior-based Interior disease, and the treatment protocol using Baekho-tang (Baihu-tang) was established. The stool condition and bowel movement reflecting the patient's defecation habits, the prime indicator of health in the Soyang constitutional type, were emphasized on their importance. 2) Sinchuk edition: The Delirium disease pattern was moved into the Exterior-cold disease, and the treatment protocol applying Jihwangbaekho-tang (Dihuangbaihu-tang) and Hyeongbangsabaek-san (Jingfangxiebai-san), with variational usage of Gypsum, was newly established. The Seong-Jeong and basal disease patterns were suggested as important factors in treating the patients. Also, it was proposed that the symptoms and signs reflecting the condition of the life-preserving energy be assessed to understand the patient's current condition. The importance of post-acute rehabilitation and aftercare as well as the most appropriate acute-stage treatment were emphasized.

• Ecology and Resilient Infrastructure
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• 제10권4호
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• pp.116-124
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• 2023

극한호우 발생빈도 증가로 소하천 홍수 피해가 증가하고 있어 소하천 리스크 관리를 위해 유량 계측 요구가 증가하고 있다. 이에 행정안전부 (MOIS) 소속 국립재난안전연구원 (NDMI)은 CCTV 기반 자동유량계측기술 (CCTV based Automatic Discharge Measurement Technology, CADMT)을 개발하고 성능 검증과 재난 리스크 관리기술 개발을 위해 시범소하천을 운영하고 있다. 본 연구는 CADMT가 설치된 능막천과 중선필천 2개 소하천을 선정하고 소하천에 가장 가까운 기상청 Automatic Weather System 강우량 자료와 유량 계측자료를 이용해 4-Parameter Logistic 방법으로 Nomograph를 개발한다. 개발한 Nomograph를 검증하기 위하여 본 연구는 각 소하천에서 홍수량을 예측하고 그 결과를 계측 유량과 비교한다. 검증 결과 예측치는 계측치를 잘 재현하는 것으로 나타나 향후, 보다 정확도 높은 계측자료가 수집되고 이에 기반한 Nomograph가 개발된다면 정확도 높은 홍수 예·경보가 가능할 것으로 판단된다.

• 한국재료학회지
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• 제14권1호
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• pp.35-40
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• 2004

In this study, dissolution characteristics of four types of commercial calcium phosphate ceramics were investigated in distilled water with respect to chemical composition and microstructure. For all samples, no significant damage was observed after 3 days of immersion. Following the 7 days of immersion, surface dissolution of the ceramics containing a crystalline phase susceptible to water such as TCP, even pure hydroxyapatite, was initiated at grain boundaries and the dissolution was extended interior to the material along the grain boundaries. In the considerably dissolved area, there was grain separation followed by the formation of 20 $\mu\textrm{m}$ of cavities. In at least one case, the residual pores on the surface appeared to initiate dissolution. In a dissolved area, a crack during the fracture propagates along the grain boundaries resulting in intergranular fracture, while transgranular fracture occurs in a dense area without significant dissolution.

• 한국세라믹학회지
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• 제23권2호
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• pp.55-63
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• 1986

In variuos physcial and chemical cause of damage of refractories for steel makin the clarification of the wear mechanism of brick is situated on important factor. In the present paper the wear mechanism of high alumina brick for the arc-furnace roof were inves-tigated by means of XRD, EPMA. SEM and microscopy. The results obtained were summerized as follows : (1) The altered layers which exist in high alumina brick used for arc-furnace roof were verified by mineral chemical analysis and EPMA. (2) The diffusion of materials combined with slag dust and iron oxide from furnace atmosphere in high basic process from hot face to interior was verified. (3)Activation energy for the synthesized slag permeated into the unused brick texture was 47-51 kcal per mole.

• Steel and Composite Structures
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• 제8권1호
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• pp.35-52
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• 2008

The paper investigates the seismic performance of a Partially-Restrained (PR) steel-concrete composite frame using the probabilistic approach. The analysed frame was tested at the ELSA laboratory of the Joint Research Centre of Ispra (Italy), while the representative beam-to-column composite connections were tested at the Universities of Pisa, Milan and Trento (Italy). The component modelling of both interior and exterior composite joints is described first, including the experimental-numerical validation. The Latin Hypercube method has been used to draw the probabilistic distribution curves of joints, and then the whole PR composite frame has been analysed. Pushover and incremental dynamic analyses have been carried out using the non-linear FE code SAP2000 version 9.1. The fragility and performance curves of the PR composite frame have been determined for four damage limit states.