A Verification of Simplified Analysis Method for Thermal Prestressing in Continuous Composite Bridge

김상효,김준환,정치영,안진희 한국강구조학회 2011 International Journal of Steel Structures Vol.11 No.4

The use of thermal-prestressing method (TPSM) prevents the occurrence of tensile transverse crack in concrete decks located in negative bending moment regions of continuous composite bridges. An accurate representation of the structural response can be obtained by means of refined analyses using three-dimensional finite element models to carry out both heat transfer and thermo-elastic calculations. So, a simplified approach was proposed for easily using the TPSM effect in design to reduce the amount of computational work of the refined analysis, but its application to real structure was not confirmed. Therefore, in this study, the verification of a simplified analysis approach has been performed to explain TPSM effects in the analysis of continuous composite bridges. For this purpose, experimental results on 2-span thermal prestressed continuous composite bridge specimens were compared with simplified analysis and refined analysis results as well as analytical approach on 2-span and 3-span continuous composite bridges. From the verification results, the proposed simplified TPSM analysis methodology shows the good predictions of the thermal prestressing effect to apply design of TPSM applied continuous composite bridges.

고령친화식품의 필요성과 시장 활성화

김상효 한국식생활문화학회 2019 한국식생활문화학회학술대회논문집 Vol.2019 No.05

實驗的 腦軟化巢의 組織學的 및 組織化學的 變化에 關한 硏究

金相孝,崔三任,李惠洙,金象皓 의과학연구소 1987 全北醫大論文集 Vol.11 No.4

Reticuloendothelial cell reaction in a central nervous system lesion was evaluated by time seqnential light microscopic examination of experimentally induced brain infarcts. Brain infarction was induced by injection of autologous blood clot to the right common carotid artery of male Wistar rats. One, two, three and four weeks after the injection, hisologic examination were done with paraffin-hematoxylin-eosin, paraffin-Masson trichrome, and epon-tolui-dine blue: and enzyme activities of acid phosphatase, alkaline phosphatase and nonspecific esterase were determined histochemically. The results were as follows. 1.Grossly, infarcts were observed mostly in the right parietal lobe. They were ischemic and only a few infarcts hemorrhagic. Infacrts of one and two weeks old appeared edematous, while those of three and four weeks old were contracted. 2.One-week-old infarcts were characterized by degeneration and necrosis of brain parenchyma. Neither infiltration of macrophages nor glial reaction was noted. 3.Necrosis was full-blown in two-week-old infarcts. Central area of the lesion contained viable capillaries with pericapillary phagocytic macrophages. Glial reaction was initiated in the borederline region between the lesion and surrounding brain tissue. 4.Infarcts of three and four weeks old showed pseudocystic spaces containing edema fluid. Pericapillary macrophages in the central area of the lesion were increased in number. Microglia, which were more apparent than in the two-week-old infarcts, showed phagocytic activity. 5. The enzyme activities in the fifarcts of one-week-old were decreased throughout the lesion. In the lesion of 2-and 3-week-old infarcts, microglia and macrophages showed strong acid phosphatase activity, and capillaries showed strong alkaline phosphatase activity:esterase activity wasmarked in the microglia, macrophages and capillaries. After 3 weeks, enzyme activities were decreased but still more prominent than in the normal controls. From the above results, it was concluded that the phagocytic cells belonging to the reticuloendothelial system consist of two cell type in brain infarcts; one is macrophages, seemingly of exudative reticuloendothelial cells, and the other is microglia, of resident reticuloendothelial cells.

전력시스템의 저주파 진동을 고려한 뉴로-퍼지 제어기설계

김상효,이준탁,정형환,이오걸 한국지능시스템학회 2003 한국지능시스템학회 학술발표 논문집 Vol.11 No.-

강합성 교량에 설치된 압전소자의 전력발생효과 분석

김상효,정치영,정하민,안진희,Kim, Sang-Hyo,Jung, Chi-Young,Chung, Ha-Min,Ahn, Jin-Hee 한국강구조학회 2010 韓國鋼構造學會 論文集 Vol.22 No.5

교량은 주행차량에 의하여 지속적이며 반복적인 변형에너지가 발생하며, 이러한 교량의 변형에너지를 압전소자를 이용하여 전기에너지로 변환 할 수 있다. 하지만 압전소자를 구조물에 부착하여 구조물의 운동에너지를 전기에너지로 변환하여 사용하기 위해서는 구조물에 작용하는 하중 및 하중에 따라 압전소자에서 발생하는 변형률 관계 등이 제시되어야 압전소자를 합리적으로 적용할 수 있는 가능성을 평가할 수 있다. 따라서 본 연구에서는 압전소자를 교량 구조물에 적용하였을 때 발생하는 전압을 평가하기 위하여 강교량을 모사한 강합성 거더 교량 실험체를 제작하고 교량의 하중효과 등을 고려한 하중을 재하하고 이에 따라 압전소자에서 발생되는 전압을 평가하고 압전전압의 제안식과 실험결과를 비교하였다. In general, moving vehicles generate continuous and repetitive strain of energy on bridges. The strain energy can convert to electric energy due to its piezoelectric element. However, some factors should be considered in order to reasonably assess the feasibility such as load distribution applied on bridges and the relationship of strains generated according to loads. This study was carried out to estimate the generated voltage when piezoelectric elements were installed to a bridge. A steel-concrete composite specimen was fabricated and loads were applied, considering vehicle load-effects. As a result, the voltage generated in the element was evaluated and compared with the analysis equation of the piezoelectric effect.

편심 브라켓 설치 온도프리스트레싱 강재보의 하중저항 성능

김상효,정치영,최규태,안진희,Kim, Sang-Hyo,Jung, Chi-Young,Choi, Kyu-Tae,Ahn, Jin-Hee 한국강구조학회 2010 韓國鋼構造學會 論文集 Vol.22 No.6

본 연구는 편심 브라켓이 설치된 온도프리스트레싱 강재보의 하중저항 성능에 관한 실험적 연구이다. 본 연구에서 제안한 강재보는 편심 브라켓을 이용하여 온도프리스트레싱 강판을 편심 설치하여, 기존 온도프리스트레싱 강재보 보다 도입되는 프리스트레스 및 단면강성을 증대 할 수 있다. 제안하고자 하는 공법의 검증을 위하여 편심 브라켓이 설치된 강재보, 온도프리스트레싱 강재보 등에 대한 정적하중 재하시험을 실시하여 강재보의 하중저항 성능을 비교 평가하였다. 또한 재료비선형성을 고려한 강재보의 구조해석을 실시하고 소성이론에 근거한 극한하중평가를 통하여 실험결과의 타당성 및 실설계에 대한 적용성을 검토하였다. 본 연구결과를 통하여 편심 브라켓이 설치된 온도프리스트레싱 강재보가 기존 온도프리스트레싱 강재보 보다 증가된 보강강판의 편심효과로 강성, 항복하중 및 극한하중이 모두 증가됨을 확인하였다. This study evaluates the load-carrying capacity of a thermal prestressed steel beam with an eccentric bracket. The steel beam that is proposed in this study has an eccentrically installed cover plate through application of the eccentric bracket. The eccentric bracket helps the steel beam achieve greater sectional stiffness and more efficiently induces prestress. A material non-linear characteristic applied finite element analysis was also conducted to check the validity of the experiments. The results of this study showed that the structural stiffness, yield load, and ultimate strength of the TPSM-applied steel beam with the eccentric bracket increased due to the eccentricity of the cover plate.

단부 수평가동-수직구속 부재를 적용한 라멘형 가설교량의 거동평가

김상효,정중연,허원호,정치영,Kim, Sang Hyo,Joung, Jung Yeun,Heo, Won Ho,Jung, Chi Young 한국강구조학회 2013 韓國鋼構造學會 論文集 Vol.25 No.1

기존 라멘형 가설교량은 주거더의 온도신축에 따라 벤트부에 과도한 수평력이 유발되는 것을 방지하기 위하여, 연장을 짧게 분할하여 가설되고 있다. 이 때 분할되는 구간에서 중복 설치되는 벤트부가 생기게 되어, 교량의 통수단면 감소와 형하공간 감소에 따른 문제와 중복 설치된 벤트부에 의한 경제성 감소 문제가 발생한다. 따라서 본 연구에서는 라멘형 가설교량 벤트부의 수평력 문제를 해결하고, 중복 설치되는 벤트부를 절감시키기 위한 단부 수평가동-수직구속 부재를 이용한 라멘화 공법을 제안하고, 이에 대한 거동특성분석을 수행하였다. Most rahmen-type temporary bridges are constructed with limited bridge length to prevent excessive horizontal forces due to the thermal expansion of main girder. To achieve a long length temporary bridge several independent bridges are required and they can not share the bents, at the rahmen-type ends, with the adjacent ones. The additional bents require more cost and reduce the section space under bridges. In order to remove extra bents with keeping the rahmen effect at the bridge ends, this study proposes a new rahmen-type movable joint system for temporary bridges.

動脈性 正中前頭部皮膚瓣 : 2예 보고

김상효 인제대학교 1980 仁濟醫學 Vol.1 No.1

비 배부(nasal dorsum)에 생긴 skin cancer의 절제후에 생긴 결손부를 보충하는 방법으로 정준전두부 피부판 2예를 시술하고 이를 보고함. Midline forehead flap based on supratrochlear vessels is a very useful skin flap in the reconstruction of partial middle nasal defects after tumor resection located on nasal dorsum or tip, and lateral defects of the nose extending into the infraorbital skin. This paper presents 2 cases of midline forehead flaps used for the reconstruction of nasal bridge (dorsum) full thickness defect resulting from the tumor resection. The method of flap transfer was a staged operation with rotating and anterior bending transfer at each case, and the result was satisfactory on aesthetic, functional and curative aspect.

DVC를 위한 LDPCA 부호

김상효 대한전자공학회 2010 대한전자공학회 워크샵 Vol.2010 No.5

가학광산 주변 중금속 오염토양의 정화를 위한 역부선 최적화

김상효,안용현,이충현,이영재,박미정,이상환,정문영 한국자원공학회 2015 한국자원공학회지 Vol.52 No.6

The contents of heavy metals such as Cu, Pb, Zn in all samples obtained from A sites around Ghahak mine exceed the 1st-area anxiety criteria of Korean soil contamination standard. When the samples were analyzed by Tessier's sequential extraction method to determine the chemical form of heavy metal components, more than of 50% belongs to residual types. First, 3 factors and 3 levels of each factor were identified through reverse flotation on one factor at a time. Based on them, the reverse flotation designed by Box-Behnken method was carried out and optimum flotation conditions were found to be 970 g/ton of MIBC dosage, 1,210 g/ton of oleic acid dosage, and 33°C of slurry temperature. Retests of contaminated soil on the conditions show that floating yield was 22%, and the removal efficiencies of Cu, Pb and Zn were 61.2%, 61.7% and 62.6%, respectively. Consequently, the results indicate that removal efficiencies of heavy metals by reverse flotation almost agree with percent of residual fraction. 가학광산 주변 A지역 토양의 중금속(Cu, Pb, Zn) 농도는 모두 토양오염공정시험기준의 1지역 우려기준을 초과하고 있다. Tessier의 5단계 연속추출법에 의해 확인한 중금속 원소는 50% 이상이 광물입자 내에 존재하는 잔류성 형태이었다. 먼저 1회 1인자 역부선 실험을 통해 파악한 3요인(올레인산 첨가량, MIBC 첨가량, 슬러리 온도)과 3수준을 근거로 실험계획법인 Box-Behnken법으로 설계한 역부선 토양정화실험을 수행하였다. 이를통해 도출한 최적의 역부선 조건은 올레인산 첨가량 970 g/ton, MIBC 첨가량 1,210 g/ton, 슬러리 온도 33°C이었다. 이러한 역부선 조건에서 오염토양에 대한 확인실험 결과 부유산출률은 22%, 그리고 중금속제거율은 Cu 61.2%, Pb 61.7%, Zn 62.6%이었다. 따라서 부선으로 제거 가능한 잔류성 중금속형태의 분포율과 역부선에 의한중금속 제거율이 거의 부합함을 확인하였다.