터널의 정량적 안정성 평가를 위한 숏크리트 모델링 방법 비교 검증에 관한 연구

유광호,이민호,박연준,You, Kwang-Ho,Lee, Min-Ho,Park, Yeon-Jun 한국터널지하공간학회 2007 한국터널지하공간학회논문집 Vol.9 No.2

지보재의 파괴가 고려된 터널의 안전율을 산정하는 방법으로 숏크리트 내에 발생하는 응력이 허용응력을 초과하면 숏크리트가 파괴된다고 가정하고 전단강도 감소기법을 이용하여 지반과 숏크리트의 파괴를 고려한 안전율을 구하는 방법이 유광호 등(2000)에 의해 제시되 바 있고, 유광호 등(2005)과 한동식 등(2006)에 의해 꾸준히 수정 보완되었다. 본 논문에서는 터널의 안전율을 산정함에 있어 시공단계를 고려할 수 있도록 기존 routine을 수정 보완하였다. 또한, 전단강도 감소기법을 사용하여 연속체요소와 보요소로 숏크리트를 모델링하고, 허용응력설계법에 근거하여 파괴를 판단함으로서 터널의 안전율을 정량적으로 산정하는 기존 연구와의 비교를 통해 적정 숏크리트의 모델링 방법을 제시하고자 한다. A method was suggested by You et al. (2000) to calculate safety factor of a tunnel based on numerical analysis with the shear strength reduction technique. In the method, the shotcrete is assumed to fail when its stress exceeds the allowable stress. The proposed method had been steadily developed by You et al. (2005) and Han et al. (2006). In this study, the previous routine was corrected so that tunnel construction sequences could be considered in calculating the safety factor of a tunnel. In addition, a proper way to model shotcrete is to be suggested by comparing with the previous studies.

터널 배면의 간극수압이 해저터널의 안정성에 미치는 영향

유광호,이광훈,You, Kwang-Ho,Lee, Kwang-Hoon 한국터널지하공간학회 2006 한국터널지하공간학회논문집 Vol.8 No.4

In this study, it was analyzed how the pore pressure behind a subsea tunnel influences on the stability of the tunnel. The tunnel is located in the soft rock layer, and a soft sandy layer and weathered soil layer are located on the top of it. Coupled numerical analyses are performed for both drained and undrained condition with varying coefficients of lateral earth pressure. In the case of undrained conditions, the stability of the tunnel was analyzed with different thicknesses of shotcrete. On the other hand, a sensitivity analysis was performed with different hydraulic conductivities and porosities of the shotcrete for the drained conditions. The stability of a subsea tunnel was evaluated in terms of safety factor suggested by You et al.(2000, 2001, 2005) based on the shear strength reduction technique. In this paper, the safety factor of a tunnel was calculated under steady state flow condition during hydro-mechanical coupled analysis. As a result, it was found that the stability of a subsea tunnel could be rather increased by allowing a proper amount of groundwater inflow into a subsea tunnel. 본 연구에서는 연약한 지반에 속하는 모래지반과 풍화토가 터널상부에 존재하며 연암층에 위치하는 해저터널을 대상으로 터널 배면의 간극수압이 터널의 안정성에 미치는 영향을 분석하였다. 이를 위해 비배수 조건과 배수조건을 가정하여 연계해석을 수행하였다. 비배수 터널의 경우에도 숏크리트 두께를 달리하여 안정성을 비교하였으며, 배수 터널의 경우는 숏크리트의 투수계수와 공극률을 달리하여 민감도분석을 수행하였다. 해저터널의 안정성은 유광호 등(2000, 2001, 2005)에 의해 제안된 전단강도감소 기법을 사용하여 수치적으로 구해지는 안전율을 사용하였다. 본 연구에서는 수리-역학적 연계해석 시 시공단계별 정상류 상태를 먼저 재현하고 터널의 안전율을 구했다. 연구결과 터널내로의 지하수 유입량을 어느 정도 허용함으로써 오히려 터널의 안정성이 높아짐을 확인할 수 있었다.

이분적 터널 암반 분류를 위한 정성적 자료의 지구통계학적 연구 II. 응용

유광호 한국지반공학회 1994 지반 : 한국지반공학회지 Vol.10 No.1

In this paper, the application of the rock classification method based on indicator kriging and the cost of errors, which can incorporate qualitative data, was presented. In particular, the binary classification of rock masses was considered. To this end, a simplified RMR system was used. Since most of subjectivity in this analysis occur during the estimation of loss functions, a sensitivity analysis of loss functions was performed. Through this research, it was found out that an expected cost of errors could successfully be used as an indication for how well a sampling plan was designed. In certain conditions, qualitative data can be more economical than quantitative data in terms of expected costs of errors and sampling costs. Therefore, an additional sampling should be carefully determined depending upon the surrounding geologic conditions and its sampling cost. The application method shown in this paper can be useful for more systematic rock classifications.

그라우팅 보강영역이 해저터널 안정성에 미치는 영향에 대한 연구

유광호,김은혜 한국암반공학회 2009 한국암반공학회 학술대회 및 세미나 자료집 Vol.2009 No.-

福祉國家 理念의 理想的 根源

兪光浩 韓獨經商學會 1985 經商論叢 Vol.3 No.-

Ausgehend von der Tatsache, daB sich Korea nach einem Wohlfahrtsstaat richtet und dabei sie sick an den fuhrenden Industriestaaten orientiert, wird in dieser Arbeit der Versuch unternommen, die ideengeschichtlichen Grundlagen bzw. ihre Entwictlung des Wohlfahrtsstaates in Europa zu untersuchen und damit das Wesen des Wohlfshrtsstaates als Iaealtyrus festzustellen. Diese Untersuchung wird dazu beitragen, Korea als einem Entwicklungsland die geschichtlichen Erfahrungen in Industrielandern fur sich auszuwerten.Selbstverstandlich erschien das Wohlfnhrtsstaat im Abendland nach dem ZweitenWeltkrieg. Jedoch die geschichtlichen Grundlagen des Wohlfahrtsstaates bsw. die staatlichePolitik fur die Wohlfahrt waren schon in der fruheren Zeit, wie in der griechischen undin der romischen Zeit, gefunden. Daher wird in dieser Arbeit der Versuch gemacht, die wichtigen Ansatze zu den Wohlfahrtsgedanken und-praktiken chronologisch dargustellen. Nach der Einleituug werden im zweiten Kapitel die Wohlfahrtsgedanken und die WohlfahrtsrnaBnahrnen vom Staat im Altertum und im Mittelalter behandelt. Im Drittenwird der im englischen Poor Law enthaltene Gedanke dargelegt. Im Vierten werden die Wohlfahrtsideen in der Aufklarungszeit, in der Bismarchschen Arbeiterversicherung und in den eniglischen soziale Gesetzgebungen am Anfang des Zwanzigjahrhunderts vorgestellt. Im Funften werden die geschichtlichen Bedingung und die daraus entstandene Wohlfahrtsidee im GroBbritanien wahrend des Zeiten Weltkrieges untersucht. Aus der oben dargestellten Analyse wird schlieBlich der Idealtypus fur den Wohlfahrts-staat aufgestellt. Daraus ergeben sich die folgenden: 1) Der Wohlfahrtsstaat bildete sich im ProseB heraus, indem die westlichen Industrielander die im IrldustrialisierungsprozeB entstandenen sozialen Flagon ablOsten, die wirtschaftlichen, politischen Schwierigkeiten in der Zeit der GroBen Depression und des Zeiten Weltkrieges iiberwunden, und dadurch auf eine bessere Welt richteten. 2) Der Wohlfahrtsstaat ist entstanden im schroffen Gegensatz zum Polizeistaat, Kriegsstaat und Diktaturstaat, aber seine Idee war uber ein fast zweitausendjahrigen Zeitraum hinwegzusammengesetzt aus verschiedcnen Ansatzen, d.h. aus Caritas(=christlicher Nachstliebe) ,aus Gegenseitigehilfe auf gemeinschaftlicher Grundlage zwischen den gleichen Berufen, wie Bergleuten, Handwerken und Ziinften im Altertum und im Mittelalter, aus der Idee von Aufk1arung-wie Freiheit. Gleichheit und Bruderlichlteit in der Franzosischen Revolution,alus der Sozialphilosophie von Sozialdemokraten, aus neuer Interpretation uber Freiheit und Gleichheit von Neo-Liberalisten, Wirtschaftstheorie von J.M . Keynes u.s.w.. 3) Der Wohlfahrtsstaat beruht sich auf den liberal-demokratischen Staat, der im wesentlichen nach dem Prinzip der freien Marktwirtschaft reguliert, wobei die Staatsinter-vention nicht auzauschlieBen ist. Der Staat zielt darauf ab, allem seinen Volk das Mindest-einkommen als Recht zu garantieren, optimale Lebensbedingungen fur bessere Lebensqualitatanzuschaffen und soziale Differenz hinsichtlich der Stellungen und Schichten zu verringern. Dieses Ziel setzen politische Demokratie und anhaltendes Wirtschaftswachstum vorsus.Erforderlich sind auch ein gut organisiertes soziales Sicherungssystem, umfassender Gesundheitsdienst und verschiedene Bildungsprogramme als Hauptmittel

인공신경망 기법을 이용한 터널 주변에서 폭발에 따른 파쇄부피 및 반지름 평가

유광호,손명균 한국암반공학회 2013 한국암반공학회 학술대회 및 세미나 자료집 Vol.2013 No.3

비뇨기과 영역에서 18F-FDG PET/CT의 임상적 역할

유광호,정호석,정승일,강택원,권동득,박광성,류수방 대한비뇨의학회 2008 Investigative and Clinical Urology Vol.49 No.9

Purpose: We evaluate the clinical roles of 18F-fluorodeoxyglucose positron emission tomography/computerized tomography(18F-FDG PET/CT) for diagnosing disease in the urogenital tract, and we compared this with the other established radiologic and pathologic diagnoses. Materials and Methods: From June 2006 to June 2007, the total number of subjects who underwent 18F-FDG PET/CT was 4,438. The mean patient age was 57.4±7.6 years and the ratio of males to females was 1.28:1. During the study period, except for 152 patients who had been given a diagnosis of urologic tumor, 614(14.3%) healthy subjects and 3,672(85.7%) patients with non-urologic tumors were enrolled. The results of detecting urologic disease by 18F-FDG PET/CT were compared with the results of detecting urologic disease by conventional imaging techniques and the postoperative histopathological diagnoses. Results: With including 147 healthy subjects and 251 non-urologic tumor patients, 398 (9.3%) urologic diseases were detected on 18F-FDG PET/CT. Diseases of the kidney, adrenal and prostate were frequently found(215, 95 and 52 patients, respectively). A thorough examination was indicated for 153(3.6%) of the patients as a result of positive findings that suggested possible tumor. A total 93 urologic cancers were confirmed, and the overall positive predictive value of 18F-FDG PET/CT was 60.7%. The positive predictive value for adrenal, kidney, bladder and prostate cancer were 87.7%, 73.3%, 57.1% and 14.0%, respectively. Conclusions: 18F-FDG PET/CT was not superior to conventional imaging for making the diagnosis of urologic disease. But 18F-FDG PET/CT was more predictive for adrenal and renal tumor than for bladder and prostate tumor. So, urologic tumor that is incidentally detected on 18F-FDG PET/ CT, and especially adrenal and renal tumor, should be closely evaluated. Purpose: We evaluate the clinical roles of 18F-fluorodeoxyglucose positron emission tomography/computerized tomography(18F-FDG PET/CT) for diagnosing disease in the urogenital tract, and we compared this with the other established radiologic and pathologic diagnoses. Materials and Methods: From June 2006 to June 2007, the total number of subjects who underwent 18F-FDG PET/CT was 4,438. The mean patient age was 57.4±7.6 years and the ratio of males to females was 1.28:1. During the study period, except for 152 patients who had been given a diagnosis of urologic tumor, 614(14.3%) healthy subjects and 3,672(85.7%) patients with non-urologic tumors were enrolled. The results of detecting urologic disease by 18F-FDG PET/CT were compared with the results of detecting urologic disease by conventional imaging techniques and the postoperative histopathological diagnoses. Results: With including 147 healthy subjects and 251 non-urologic tumor patients, 398 (9.3%) urologic diseases were detected on 18F-FDG PET/CT. Diseases of the kidney, adrenal and prostate were frequently found(215, 95 and 52 patients, respectively). A thorough examination was indicated for 153(3.6%) of the patients as a result of positive findings that suggested possible tumor. A total 93 urologic cancers were confirmed, and the overall positive predictive value of 18F-FDG PET/CT was 60.7%. The positive predictive value for adrenal, kidney, bladder and prostate cancer were 87.7%, 73.3%, 57.1% and 14.0%, respectively. Conclusions: 18F-FDG PET/CT was not superior to conventional imaging for making the diagnosis of urologic disease. But 18F-FDG PET/CT was more predictive for adrenal and renal tumor than for bladder and prostate tumor. So, urologic tumor that is incidentally detected on 18F-FDG PET/ CT, and especially adrenal and renal tumor, should be closely evaluated.

Development and Evaluation of Non-Hydrous Skin Analogue Liquid Crystal using Thermo-Sensitivity Smart Sensor

유광호,홍재화,은소희,정태화,정관영 한국응용과학기술학회 2014 한국응용과학기술학회지 Vol.31 No.3

In this study, skin permeation enhancement was confirmed by designing it to have a structure and composition similarity to the intercellular lipids that improve miscibility with skin by cross-linked lipids poloxamer. The cross-linked lipids poloxamer was synthesized and analyzed by 1H NMR that structure dose had conjugated pluronic with ceramide3. Active component is released by modification of liquid crystal structure because PPO part, large-scale molecule block of pluronic, has hydrophobic nature at skin temperature of 35℃. Conjugated pluronic with ceramide3 was synthesized using Pluronic F127 and p-NPC (4-nitrophenyl chloroformate) at room temperature yielded 89%. Pluronic(Ceramide 3-conjugated Pluronic) was synthesized by reaction of p-NP-Pluronic with Ceramide3 and DMAP. The yield was 51%. This cross-linked lipids poloxamer was blended and dissolved at isotropic state with skin surface lipids, phospholipid, ceramide, cholesterol and anhydrous additive solvent. Next step was preceded by α-Transition at low temperature for making the structure of Meso-Phase Lamella, and non-hydrous skin analogue liquid crystal using thermo-sensitivity smart sensor, lamellar liquid crystal structure through aging timeFor confirmation of conjugation thermo-sensitivity smart sensor and non-hydrous skin analogue liquid crystal, structural observation and stability test were performed using XRD(Xray Diffraction), DSC(Differential Scanning Calorimetry), PM (Polarized Microscope) And C-SEM (Cryo-Scanning Electron Microscope). Thermo-sensitivity observation by Franz cell revealed that synthesized smart sensor shown skin permeation effect over 75% than normal liquid crystal. Furthermore, normal non-hydrous skin analogue liquid crystal that not applied smart sensor shown similar results below 35℃ of skin temperature, but its effects has increased more than 30% above 35℃.

Inflammatory Myofibroblastic Tumor of the Kidney Misdiagnosed as Renal Cell Carcinoma

유광호,임창민,김명기,권동득,박광성,류수방,최찬 대한의학회 2010 Journal of Korean medical science Vol.25 No.2

The inflammatory myofibroblastic tumor (IMT), also knowns as inflammatory pseuduotumor,is a soft tissue lesion of unknown etiology. In the urogenital tract, IMT mainly affects the urinary bladder or prostate, but rarely the kidney. It has been considered as a nonneoplastic reactive inflammatory lesion, but nowadays, it is regarded as a neoplasm due to its high recurrence rate and metastasis. We describe a case of a 61-yr-old woman that had originally been misdiagnosed as renal cell carcinoma,which was pathologically revealed to be an IMT.

중동 분쟁 1년의 경제적 영향과 시사점

유광호,이지은 대외경제정책연구원 2024 KIEP 세계경제 포커스 Vol.2024 No.-