Steepest Descent Method에 의한 複合材를 利用한 Multi-ringed Flywheel의 最適設計

洪錫雨 충남대학교 공업교육연구소 1981 論文集 Vol.4 No.2

效果的인 에너지 貯藏裝置인 Flywheel에 單位 體積當 貯藏되는 運動에너지를 最大로 하기 위하여, 應力과 設計變數에 대한 制限條件을 주고 最適設計의 方法을 Steepest Descent Method로 하여 複合材로 製作된 Multi-ringed Flywheel을 最適設計하였으며, 이를 遂行하는 Computational Algorithm을 提示하였다. 數値例로써 Glass/Epoxy 複合材를 선택하였다.

실드터널 시공시의 지표 구조물의 침하 억제 대책에 관한 연구

임종철,윤이환,박이근,고호성,홍석우 釜山大學校生産技術硏究所 1999 生産技術硏究所論文集 Vol.56 No.-

연약지반 터널 굴차시 실드공법은 근접 구조물 안전에 유용한 공법이다. 하지만 실드 터널 공법은 터널 주변 지반의 변형을 최소화 할 수 있는 장점을 가지는 반면 테일 보이드(Tail Void)에 그라우트된 주입재가 경화되기 전에 발생하는 지반 변형은 피하기 어렵다. 본 연구에서는 테일 보이드로 인한 인접 구조물의 침하를 억제하는 방법중 하나인 마이크로파일(micropile)의 영향을 모형실험을 통하여 규명하였다. 기초적인 실험 결과로써 마이크로파일 보강시 마이크로파일의 효과적인 설치방향과 침하 억제비를 밝혔다. In soft ground tunneling, shield method is very good for safety of neighboring structures. Although shield tunnel method has the merits to minimize the deformation of ground around tunnel, ground deformations occurred until the material grouted in tail void hardens are inevitable. In this study, the effects of micropile used as one method to restrain the settlement of neighboring structures by the tail void are studied by laboratory model tests. As a basic test result, the effective direction of micropile and the restraint rate of settlement by micropile reinforcement are known.

Ultimate Uplift Capacity Relation of Plate Anchor Using Model Testing

홍석우,금동헌,서민수 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.12

Friction anchors are gaining popularity in civil structures. However, the bond length can be increased to use the friction between the ground and friction anchor body. They are often bonded deep in the ground and fixed to the bedrock; this causes problems, including the anchor overlapping the underground structure or invading the lower part of another structure when anchors are installed in downtown sites. Herefore, combination anchors that combine the advantages of plate anchors that resist uplift because of the ground’s bearing capacity with a friction-type anchor have gained attention. However, the ground failure mechanism of plate anchors applied to combination-type anchors has not been accurately analyzed; therefore, various theoretical anchor uplift capacity formulas have been proposed. A model test was performed in this study by forming a sandy ground in a state of plane strain to verify the uplift capacity of the plate anchor installed at a shallow depth and ground failure mechanismPhotos obtained from experiment were evaluated to analyze the shape of the ground failure of the plate anchor. Furthermore, by classifying the depth of the installed anchor, an equation for calculating the ultimate uplift capacity of the plate anchor was proposed according to the classified depth. A model test was performed in this study based on the formation of a sandy ground in a state of plane strain to verify the uplift capacity of the plate anchor installed at a shallow depth and ground failure mechanism. Photos obtained from experimental tests were evaluated to analyze the shape of the ground failure of the plate anchor. Furthermore, by classifying the depth of the installed anchor, an equation for calculating the ultimate uplift capacity of the plate anchor was also proposed according to the classified depth.

신생아 호흡 곤란 증후군에서 CurosurfⓇ와 NewfactanⓇ의 치료 효과 비교

홍석우,이은호,김승연,박호진 대한신생아학회 2008 Neonatal medicine Vol.15 No.2

Purpose : The aim of this study was to compare the clinical effects of modified porcine (CurosurfⓇ) and bovine (NewfactanⓇ) surfactants in the treatment of neonatal respiratory distress syndrome. Methods : Between April 2004 and December 2006, 65 neonates (birth weight ≤2,500 g and gestational age ≤35 weeks) with neonatal respiratory distress syndrome were treated in our neonatal intensive care unit with surfactant. Thirty-one neonates received CurosurfⓇ and 34 neonates received NewfactanⓇ. The neonates were not enrolled if they had major congenital anomalies or meconium aspiration syndrome. We compared the changes in respiratory parameters after surfactant instillation, the incidences of acute and chronic complications, and the mortality between the two treatment groups. Results : Neonatal and maternal demographic characteristics were not different between the groups. The patterns of change in the respiratory parameters after surfactant instillation were not statistically different between the groups. The incidences of surfactant reinstillation and acute complications, such as pneumothorax, patent ductus arteriosus, pulmonary hemorrhage, and grade 3-4 intraventricular hemorrhage, were not different between the neonates who received CurosurfⓇ and the neonates who received NewfactanⓇ. There were no statistically significant differences in the duration of mechanical ventilation, oxygen therapy, hospitalization, prevalence of bronchopulmonary dysplasia, periventricular leukomalacia, retinopathy of prematurity, necrotizing enterocolitis, and mortality between the groups. Conclusion : In the present comparative study, no significant differences in the clinical effects of CurosurfⓇ and NewfactanⓇ were observed.

3T3-L1세포에서 AMPK 활성이 TNF-α에 의한 지방세포 대사 이상 및 Wnt와 sFRP5에 미치는 영향

홍석우,이진미,최지훈,박세은,이은정,박철영,오기원,박성우,김선우,이원영 대한비만학회 2012 The Korean journal of obesity Vol.21 No.1

연구목적: 지방세포에서 만성적인 염증은 비만 및 대사질환과 매우 밀접하게 관련되어 있다. 본 연구는 지방세포의 염증유발 및 회복 과정에서 Wnt 신호전달체계 및 지방대사의 변화를 관찰하였다. 방법: 3T3-L1 지방 세포주에 Tumor-necrosis factor (TNF)-α를 단독, 혹은 Aminoimidazole carboxamide (AICAR)와 함께 처리하여 염증의 유발 및 회복을 유도한 지방세포 모델을 제작하였다. Wnt 신호전달체계 및 지방대사에관련된 인자의 변화를 관찰하였다. 결과: 지방세포에 TNF-α의 처리는 염증 인자의 발현 증가및 non-canonical Wnt 신호전달체계의 활성화를 유도하면서,PPAR-γ의 발현 감소와 지방분해가 증가를 유도하였다. AICAR의 처리는 TNF-α에 의한 염증반응을 억제하고,non-canonical Wnt 신호전달체계 및 지방대사의 변화를 회복시켰다. 또한 항염증 아디포카인인 sFRP5의 분비가 유의하게증가하였다. 결론: 본 연구는 염증이 유발된 지방세포에서 AMPK 활성화가 sFRP5 분비를 촉진하여 non-canonical Wnt 신호전달체계를 억제하고, 염증억제 및 지방대사를 회복할 수 있음을 제시한다.

유리미세 가공을 위한 전기화학적 방전가공법 ( Electrochemical Discharge Machining for Drilling of Glass Substrate )

홍석우,정귀상 대한전자공학회 1997 대한전자공학회 학술대회 Vol.1997 No.1

저혈당성 뇌병증에 의한 시각유발전위검사(VEP) 이상을 보인 신생아 2례

홍석우,박호진,김승연 대한신생아학회 2008 Neonatal medicine Vol.15 No.1

Although neonatal hypoglycemia is a common metabolic abnormality in newborn infants, brain injuries resulting from isolated neonatal hypoglycemia are rare. Many infants who are hypoglycemic do not exhibit clinical manifestations, while other infants are symptomatic and at risk for permanent brain damage. There is no disagreement that hypoglycemia can cause neonatal encephalopathy and result in permanent brain injury. Occipital brain injury associated with neonatal hypoglycemia can result in long-term disability, epilepsy, and visual impairment. Infants should receive ongoing developmental and visual surveillance for lateonset epilepsy, and visual or cognitive impairment. We report two cases of newborn infants with abnormal visual evoked potentials (VEP) caused by neonatal hypoglycemic encephalopathy.

이자섬 세포의 발달과 베타세포의 분화에서 clusterin의 역할

홍석우,박인선,민본홍,신용재,Ranjan KC,이송 대한당뇨병학회 2007 Diabetes and Metabolism Journal Vol.31 No.1

-Clusterin is a highly glycosylated heterodimeric glycoprotein that plays diverse biological roles in various organs. The secreted clusterin has been established as a major form of the protein that exerts diverse tissue effects. For instance, clusterin is known to act in cell protection through the actions of extra-cellular molecular chaperones. In the extracellular milieu, clusterin participates in specific interactions with a diverse array of native biological molecules including LRP-2 (Lipoprotein receptor-related protein 2, also known as gp330 or megalin), which is involved in ligand endocytosis at the surfaces of certain epithelia.Clusterin is expressed transiently in developing and differentiating endocrine pancreatic cells and might be involved in pancreas development. This transient expression of clusterin at specific time points of pancreas development and cell differentiation during pancreas regeneration implies that the protein is a regulatory factor for cytodifferentiation as well as for replication. A specific action of the clusterin in the reconstruction and remodeling of the endocrine pancreas has been demonstrated. It also strongly stimulates duct cell differentiation into insulin-secreting cells under in vitro culture conditions. Clusterin appears thus as a potent regulator of insulin cell morphogenesis. (J Kor Diabetes Assoc 31:1~8, 2007)

Fatigue Life Prediction of Caulking-Joined Parts

홍석우,석창성,구재민,강정훈,장인철 한국정밀공학회 2014 International Journal of Precision Engineering and Vol.15 No.6

Caulking has merits of easy manufacturing and assembly, and reduced product cost. However, though the design of the caulkingprocess is very important in order to obtain satisfactory strength, research on caulking has been insufficient. Therefore, tensile andfatigue tests were conducted for the evaluation of the caulked part of a drum in a washing machine. The caulking process wassimulated by finite element analysis, and the residual stress of the caulked part was evaluated. The residual stress of the caulked partwas applied to the S-N curve of the fatigue test, and the notch effect of the caulked part was applied to the S-N curve of virgin material. As a result, the S-N curve of the caulked part can be predicted from the S-N curve of virgin materials.

문제적 관계의 우크라이나 언어와 정체성

홍석우 한국외국어대학교(글로벌캠퍼스) 동유럽발칸연구소 2022 동유럽발칸연구 Vol.46 No.1

Language has been understood as an important element and symbol that determines the identity of a nation and state beyond a means of communication. However, since the collapse of Kyivan Rus’ in the 13th century, Ukrainian people has been forced to assimilate language, culture, and identity under the rule of other nations, and it has been difficult to preserve the Ukrainian language and identity. Therefore, language and identity have been placed in a very complex and problematic relationship in Ukraine and have been a factor causing socio-political problems. Therefore, in this paper, how the relationship between language and identity has deepened into a problematic relationship in Ukraine and its impact on Ukrainian society are investigated. In particular, this study examines how the relationship between language and identity in Ukraine has changed and progressed as the Euromaidan revolution intensified and Russia intervened in the Crimean Peninsula and Donbass issue, and discusses its impact on Ukraine. 언어는 의사소통의 수단을 넘어 한 민족과 국가의 정체성을 결정짓는 중요한 요소와 상징으로 이해되어왔다. 그런데 우크라이나는 13세기 키예프루스의 붕괴 이후부터 최근까지 타민족의 지배아래 언어와 문화, 정체성의 동화를 강요받아 오면서 우크라이나어와 정체성 보존에 어려움을 겪어왔다. 따라서 우크라이나에서 언어와 정체성은 매우 복잡하고 문제적인 관계에 놓이게 되었고 사회-정치적 문제를 일으키는 요인이 되어왔다. 따라서 본고에서는 언어와 정체성의 관계가 우크라이나에서 어떻게 문제적 관계로 심화되어 왔는지 파악하고 우크라이나 사회에 미친 영향에 대해 알아보았다. 특히 본 연구는 유로마이단 혁명이 격화되고 러시아가 크림반도와 돈바스 문제에 개입하게 되면서 우크라이나의 언어와 정체성 사이의 관계가 어떻게 변화되고 진행되어 갔는지 점검하고 그 영향에 대해 논의한다.