• 화약ㆍ발파
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• 제23권4호
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• pp.31-44
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• 2005

높은 현지응력 조건하에서는 굴착 후에 응력 재분배와 응력 교란에 의해 발생하는 터널 주변의 손상영역을 평가할 필요가 있다. 따라서 암석의 변형 및 파괴 특성을 규명하는 것이 중요하다고 할 수 있다. 본 연구에서는 미소균열들의 전파와 결합에 의해 형성되는 암석의 파괴 및 손상 메커니즘을 점이동 회귀분석 기법과 단축압축시험 동안 측정된 미소파괴음으로부터 조사하고자 하였다. 특히 암석의 손상기준들을 보다 체계적으로 결정하기 위한 수정 방법을 새롭게 제안하였고 성공적으로 적용하였다. 실험결과, 황등화강암과 여산대리석 모두에서 균열개시응력과 균열손상응력은 단축압축강도의 각각 $33{\~}36\%$와 $84{\~}89\%$ 수준인 것으로 나타났다. 하지만 여산대리석에서 정규화한 균열닫힘응력 수준은 황등화강암과 비교할 때 더욱 크게 나타났다. 또한 황등화강암에서 발생한 축방향 변형은 탄성변형 단계와 초기 미소균열 발생 과정에서 크게 발생하였다. 하지만 여산대리석에서 발생한 축방향 변형은 초기 균열들의 닫힘과 불안정한 균열전파에 의해 주로 발생하였다. 반면 단축압축조건하에서 암석의 횡방향 변형은 거의 대부분 균열손상응력 수준 이후에 발생하는 불안정한 균열전파로 인해 발생하는 것으로 나타났다.

• 한국구조물진단유지관리공학회 논문집
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• 제27권6호
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• pp.55-61
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• 2023

본 연구에서는 항만시설물의 환경적인 요인과 열화 특성을 고려한 유지관리 방안을 수립하기 위한 기초연구로서 인천 및 부산 항만시설물을 대상으로 점검 보고서를 참고하여 열화 및 손상정도를 검토하였으며 현재 지침에서 제시하고 있는 열화환경평가와의 관계를 분석하였다. 인천 및 부산 항만시설물의 손상 정도를 분석한 결과 인천항이 부산항보다 약 3배 정도 높은 손상률을 나타내었으며 인천항의 경우 철근부식 손상과 외부요인 손상의 비율이 유사하게 나타났으며, 부산항의 경우 철근부식 손상이 외부요인 손상의 비율보다 높게 나타났다. 한편 지침에서 제시하고 있는 열화환경 평가와 비교한 결과 지침에서 제시하고 있는 열화환경 평가를 바탕으로 항만시설물을 평가할 경우 정량적 평가를 수행함에 다소 한계가 있는 것으로 확인되었으며 기존 문헌을 참고하여 조수간만의 차를 바탕으로 분석을 수행하였다. 인천 및 부산 지역에 대한 조수간만의 차를 분석한 결과 인천이 부산보다 약 5배 높은 조수간만의 차를 나타내었으며 이는 기존 열화환경 평가 항목보다 지역 및 해역에 대해 정량적으로 열화환경을 평가할 수 있는 항목이 될 수 있을 것으로 판단된다.

• Korean Journal of Acupuncture
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• 제26권1호
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• pp.111-123
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• 2009

Objective : The purpose of this study is to observe the effect of high frequency electro-acupuncture (hf-EA) at Yanglingquan(GB34) on $CCl_4$-induced liver damage in rats. Methods : The author performed several experimental items, including measurements of body weight and liver weight, hematological analysis for RBC, WBC, PLT, hemoglobin, lymphocytes, neutrophils, monocytes and biochemical assays for ALT, AST, ALP and total cholesterol in serum, and histological analysis of liver tissue. Results & Conclusion : 1. WBC level in blood was slightly reduced by acupuncture and hf-EA at GB34. 2. Lymphocyte level in blood was decreased by $CCl_4$-intoxication and significantly increased by acupuncture and hf-EA at GB34. 3. Neutrophils level in blood was slightly reduced by acupuncture and hf-EA at GB34. 4. ALT and AST in serum were reduced significantly by acupuncture and hf-EA at GB34. 5. The pathological changes of liver tissue induced by $CCl_4$ was reduced by hf-EA at GB34. 6. No significant difference was found between the effects of acupuncture and hf-EA on CCl4-induced liver damage in rats.

• 한국안전학회지
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• 제32권4호
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• pp.122-128
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• 2017

Recently, accidents such as human accidents are increasing rapidly due to natural disasters and changes in social conditions due to abnormal weather. As a result, damage has been causing massive damage unlike the past. In the case of small and medium enterprises excluding financial institutions and big company, there is no system for prevention and restoration for stable operation from various risks such as human and natural disasters. As the current disaster continues, public and private companies have raised the need for BCM, and with the introduction of the ISO22301 certification system, the company has been establishing and operating Enterprise Disaster Management Standards in the Ministry of Public Safety and Security since 2007. However, in most SMEs, it is hard to bear the input of internal labor and investment cost, and there is a lack of personnel with expertise to conduct BCM diagnosis. Therefore, in this paper, we will study the diagnosis level of enterprise continuity plan which is commonly used in Korea and abroad. Based on this, we will study the BCM system diagnosis method which can be applied to small and medium enterprises in Korea efficiently.

• 대한한의학회지
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• 제21권1호
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• pp.68-76
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• 2000

Objectives: This experiment was conducted to verify the effects of Chungganhaeju-tang(Qingganjiejiu-tang) on the alcohol metabolism and liver functions, by measuring the activity levels of ADH and ALDH, as well as glucose, triglyceride, and BUN. Damage of the liver cells caused by alcohol was determined through the examination of serum levels of AST, ALT, ALP, LDH, and uric acid. Methods: Sprague-Dawley rats were used in this experiment and the rats were divided into control and experiment groups. Chungganhaeju-tang(Qingganjiejiu-tang) extract was orally administered in the experiment group for three weeks. Each group was further classified into two sub-groups, and control group's blood was taken without oral ingestion of alcohol, while the experiment group' s blood was withdrawn after ingestion of alcohol. Evaluation of damage level was done considering the presence of extract and alcohol. Results: In this experiment, Chungganhaeju-tang(Qingganjiejiu-tang) significantly suppressed the activity of ADH which is a precursor enzyme of acetaldehyde, but didn't cause significant changes in the activity of ALDH which is a catabolic enzyme. Decreased glucose level due to alcohol consumption was recovered back to the normal level and increased levels of triglyceride, BUN, AST, ALT, ALP, LDH, and uric acid were significantly reduced. Conclusions: These experiment results suggest that Chungganhaeju-tang(Qingganjiejiu-tang) inhibits the formation of acetaldehyde in the metabolism of alcohol, and affects the recovery of weakened liver functions due to alcohol.

• 한국동물학회지
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• 제37권2호
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• pp.232-239
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• 1994

RecA protein plans a central role in homologous recombination and DNA repair in Escherichia cofi (E. colD. The function 8nd structure of this protein are universal in prokarvotes and also conserved in eukaryotes such as yeast. The RecA-like protein with 74 lInDa in size has already been identified and purified from a fission yeast Schizosaccharomyces pombe (5. pommel (Lee, 19911. From this study it was revealed that the RecA-like protein of 5. pombe was highly inducible to various DNA damaging agents and inhibitors of nucleotide pool svnthesizins enzymes. The cellular level of the 5. pombe RecA-like protein wi,u markedly increased, upto 5- to 10-fold, by treatment with various DNA-damains agents including ultraviolet (UV) light, methyl methanesulfonate WS),4-nitroquinoline-1-oxide (4-NQO), and mitomycin-C (MMC), similar to E. cofi RecA protein. Interestingly, the protein level was also increased by inhibitors of nucleotide pool forming enzlwnes such as methotrexate (MTX) and hvdroxvurea (HU). The most effective doses for the inducibility of 4-NQO, MMS, W, MMC, MTX, and HU were 0.2 Ug/ml, 30 mM, 200 J/ma, 0.4 $\mus/ml,$ 1 Ug/ml, and 100 mM, respectively. The range of effective duration time for the inducibilitv of RecA-like protein was from 270 to 450 mins. These results suggest that the 5. pombe RecA-like protein also platys an imortant role in cellular responses to DNA damage as in E. coli system.

• 한국터널지하공간학회 논문집
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• 제4권1호
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• pp.3-12
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• 2002

본 연구는 우면산터널 시공에 따른 예술의 전당내의 오페라극장 구조물에 대한 영향을 검토하고 필요시에는 적절한 대책을 조기에 강구하기 위하여 3차원 유한요소해석을 실시하였다. 쌍굴터널 굴진시 지반거동의 영향범위내에 있는 오페라극장은 문화재급의 건축물로써 그 기초형식 또한 다양하다. 그러므로, 건물구조의 3차원적인 특성과 기초형태의 변화를 이상적으로 모델링하고, 3차원해석 결과에 따른 시공전 예측과 시공중 안정성확인을 평가할 수 있도록 검토하였다. 문제발생시 신속한 대처를 할 수 있고, 터널굴진시 정보화 시공이 적용될 수 있도록 관리기준치를 단계적으로 변화 설정하였다.

• Journal of Chest Surgery
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• 제22권3호
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• pp.402-415
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• 1989

Extracorporeal circulation leads to functional disorder and structural damage of organs, especially hematologic and pulmonary system, mainly by sequestration of neutrophils and deposition of macrophages at lung. Then, proteases are secreted, which insult vascular basement membrane of pulmonary capillary and alveolar septa of the lung. Among these, the most important protease at lung is elastase, because major component of lung is elastin. For prevention of lung injury, inactivators or antidotes to elastase should be necessary and Alpha 1-Proteinase Inhibitor is the elastase inactivator. Clinical experimental study was carried out to investigate the immediate postoperative change of serum Alpha 1-PI level following cardiopulmonary bypass for 20 heart cases [congenital 16 cases, acquired 4 cases] and 10 control [subtotal gastrectomy] cases. Also preliminary study was performed for 31 cases of open heart patients. The results were as follows: l. Immediate postoperative serum levels of Alpha 1-PI was significantly decreased at open heart surgery group [P< 0.005], but not decreased at control group. 2. There were no significant difference in change of serum Alpha 1-PI level between and membrane and bubble oxygenator group.Z 3. There were no significant difference in changes of serum Alpha 1-PI level between CHD and AHD. Alpha 1-PI is consumed at lung during cardiopulmonary bypass and increase after operation compensatedly and protect multiple organic damage especially lung. Therefore, Alpha 1-PI can be indicator for evaluation of prevention and treatment of pump-lung syndrome.

• 한국산업보건학회지
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• 제22권2호
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• pp.164-173
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• 2012

Objectives: Epichlorohydrin is a material that has been predicted to have high volatility and strong toxicity and is used normally in working area. Therefore, the hazardous and dangerous level and the foreign management system about epichlorohydrin should be invested at home and abroad and through hazard assessment for occupational environment measurement and exposure status of industrial workers in domestic working area. Methods: To assess risk and to suggest Development and Adoption to prevent health damage of workers owing to the epichlorohydrin exposure, the hazardousness and dangerousness of epichlorohydrin and its practical examples and regulation level for domestic and abroad health impairment are researched on the base of various references. Results: The epichlorohydrin caused skin and mucus membrane irritation, respiratory paralysis, kidney and live damage under the influence of acute toxicity and in animal study, it was confirmed as a doubtful carcinogenic substance to trigger reducement of sperm number and reproduction ability, abnormal spermatogenesis, mutagen, increase of forestomach epithelium and occurrence of papilloma and so on, as well as it induced stimulus asthma and allergic contact dermatitis for exposure workers. Conclusions: Epichlorohydrin was found to occur allergic contact dermatitis, carcinogenesis doubt and reproduction toxicity and was verified as a material which would be established reinforcement of management level to care health of handlers, such as denotement dangerousness of skin absorption.

• 한국군사과학기술학회지
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• 제24권3호
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• pp.339-347
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• 2021

Recently, the incidence of lightning in Korea has been increasing more and more. The damage caused by lightning is also getting worse. Lightning protection system is a prerequisite, not a sufficient condition. Considering the characteristics of lightning, there is a high frequency of lightning strikes in highlands. So, high grades of LPS should be applied to ground facilities of anti-aircraft weapons systems. 4-Level LPS was applied on groung facilities of anti-aircraft weapons system based on lightning incidence rate in past. There are some possibilities of damage from lightning in anti-aircraft weapons system. So, we have to readjust the LPS level with grounding, lightning rods and surge protect device based on lightning incidence rate in now days. Propose 2-level LPS and design with lightning rods, surge protector, separated grounding in this paper.