• Title/Summary/Keyword: harbor structure

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Attempt to Predict Service Life of RC Structures in Marine Environment by In Situ Investigation (해양성 환경에 위치한 RC 구조물의 현장조사에 의한 내구수명예측 시도)

  • 이창수;설진성;윤인석;이규동
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.1255-1260
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    • 2000
  • The service life is defined as the period of the period of time, until repair becomes necessary to maintain the serviceability of structures. It is getting more common to specify the service life of a structure, particularly structures exposed to de-icing salt water. To accomplish this study, pier in the harbor was chosen as a experimental area. The service life of decks in marine environment was calculated as sum of three period ; initiation period, propagation period and cracking period. The object of this study is to indicate where and how measures can be adopted for checking relevant service lifes.

A Study on Mapping of Liquefaction Hazard at a Megalopolis in Korea (국내 광역 단위 지역의 액상화 재해도 작성을 위한 연구)

  • Choi, Jae-Soon;Ku, Tai-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.09a
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    • pp.1246-1249
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    • 2009
  • Liquefaction hazard caused by earthquake is the damage in a wide range. Until now, liquefaction hazard potential at a small area or most structure in Korea was assessed by modified Seed & Idriss method. However, it has been known that this method is not proper for metropolitan area due to a lot of time and data to perform the related ground response analyses such as Shake program. For these reasons, the current method has been used facilities or structures, not metropolitan area. In this study, several contents in seismic design of Eurocode and Korean seismic design standard for Port and Harbor were introduced and applied for assessing the liquefaction potential and mapping the liquefaction hazard by LPI(Liquefaction Potential Index). Finally, Ulsan metropolitan city was practically drawn in two dimensional space.

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Construction Monitoring of Geotextile Tube at Young-Jin Bay and Stability Analysis by Hydraulic Model Tests (영진만 지오텍스타일 튜브의 현장 시공계측 및 수리모형시험을 통한 안정성분석)

  • 신은철;오영인;이명호
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.549-556
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    • 2002
  • Geotextile tubes hydraulically or mechanically filled with dredged materials have been applied in hydraulic and coastal engineering in recent years(shore protection structure, detached breakwater, groins and jetty). It can also be used to isolate contaminated material from harbor, detention basin dredging, and to use this unit as dikes for reclamation work. Recently, new preliminary design criteria supported by model and prototype tests, and some stability analysis calculations have been studied. The stability analysis of geotextile tube is composed geotechnical and hydrodynamic analysis. The stability check points are sliding failure, overturning, bearing capacity failure against the wave attack. In this paper presented the construction procedure and in-situ measurement(properties of filling material, effective height variation, stress variation at geotextile tube bottom) of geotextile tube at Young-Jin Bay and stability analysis by theoretical method and hydraulic model tests

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Analysis of Chloride Ion Penetration for Harbor Concrete Structure with In-situation Environment (항만 콘크리트 구조물의 현장환경변화에 따른 염소이온 침투해석)

  • Han, Sang-Hun;Jang, In-Sung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.225-228
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    • 2004
  • In order to estimate the chloride ion penetration, the model, which considers diffusion and sorption, is proposed on the basis of Finite Element Method (FEM). The FEM program provides the estimation of chloride concentration according to cyclic humidity and sorption. After the humidity diffusion analysis is carried out, the chloride ion diffusion and sorption analysis are conducted on the basis of the preestimated humidity data in each element. Each element has different analysis variables at different ages and locations. At early ages and constant outer humidity, the difference between inner and outer relative humidity causes the chloride ion penetration by sorption. As the humidity diffusion reduces the difference with age, the effect of sorption on the chloride ion penetration decreases. By the way, the cyclic humidity increases the effect of sorption on the chloride ion penetration at early ages, and the quantity of chloride ion around steel at later ages. Therefore, the in-situ analysis of chloride ion penetration for marine concrete structures must be performed considering the cyclic humidity condition and the long term sorption.

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Study on Application of Criteria of Lateral Flow in Soft Soils (측방유동 판정기준의 적용성 연구)

  • Chae, Young-Soo;Moon, Han-Joong;Kim, Dae-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.2
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    • pp.219-223
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    • 2006
  • In this paper, the criteria of the lateral displacement in soft soil due to embankment were evaluated. The lateral displacement was measured at a pier structure in a new harbor construction site, and the measurement was compared with the criteria. The results by the measurement such as the critical pressure causing lateral movement in terms of undrained strength, the lateral movement index by Japan Highway Co., the lateral displacement index by Japan Construction Ministry, the modified index by Korean Highway Co. were estimated to be lower than the respective index values.

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Rx for Tissue Restoration: Regenerative Biology and Medicine

  • Stocum, David L.
    • Animal cells and systems
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    • v.5 no.2
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    • pp.91-99
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    • 2001
  • Vertebrates regenerate tissues in three ways: proliferation of cells that maintain some or all of their differentiated structure and function, redifferentiation of mature cells followed by proliferation and redifferentiation into the same cell type or transdetermination to another cell type, and activation of restricted lineage stem cells, which have the ability to transdetermine to different lineages under the appropriate conditions. The behavior of the cells during regeneration is regulated by growth factors and extracellular matrix molecules. Some non-regenerating tissues are now known to harbor stem cells which, though they form scar tissue in vivo, are capable of producing new tissue-specific cells in vitro, suggesting that the injury environment inhibits latent regenerative capacity. Regenerative medicine seeks to restore tissues via transplantation of stem cell derivatives, implantation of bioartificial tissues, or stimulation of regeneration in vivo. These approaches have been partly successful, but several research issues must be addressed before regenerative medicine becomes a clinical reality.

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A site-specific CFD study of passing ship effects on multiple moored ships

  • Chen, Hamn-Ching;Chen, Chia-Rong;Huang, Erick T.
    • Ocean Systems Engineering
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    • v.9 no.1
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    • pp.43-77
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    • 2019
  • A local-analytic-based Navier-Stokes solver has been employed in conjunction with a compound ocean structure motion analysis program for time-domain simulation of passing ship effects induced by multiple post-Panamax class ships in the exact condition of a real waterway. The exact seabed bathymetry was reproduced to the utmost precision attainable using the NOAA geophysical database for Virginia Beach, NOAA nautical charts for Hampton Roads and Norfolk harbor, and echo sounding data for the navigation channel and waterfront facilities. A parametric study consists of 112 simulation cases with various combinations of ship lanes, ship speeds, ship heading (inbound or outbound), channel depths, drift angles, and passing ship coupling (in head-on or overtaking encounters) were carried out for two waterfront facilities at NAVSTA Norfolk and Craney Island Fuel Terminal. The present paper provides detailed parametric study results at both locations to investigate the site-specific passing ship effects on the motion responses of ships moored at nearby piers.

AUV Platform Design for Unmanned remotely Construction and Harbor Infrastructure (항만 실시간 감시 및 시공지원을 위한 AUV 플랫폼 설계)

  • Park, Yong-Gu;Lee, Young-Pil;Li, Ji-Hong
    • The Journal of the Korea institute of electronic communication sciences
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    • v.16 no.6
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    • pp.1089-1094
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    • 2021
  • In order to support the restoration and construction work of port infrastructure facilities damaged or damaged due to disasters and disasters, it is linked with work equipment based on the performance of duties such as regular patrol in the port, monitoring the underwater environment, and acquisition of underwater configuration information in the port, Define content related to AUV platform analysis and design that can support construction.

Artificial Resort Beach Development and Numerical Analysis (인공휴양해변개발과 수치실험분석)

  • Lee, Joong Woo;Jeong, Myoeng Seon
    • Journal of Korean Port Research
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    • v.4 no.1
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    • pp.21-31
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    • 1990
  • The application of computer model to the port and harbor development is categorized in the field of port development policy, economic analysis and evaluation, civil engineering analysis, hydrodynamic analysis, evaluation of social and natural environment effect, etc. The study in this paper, however, is limited to hydrodynamic analysis, especially the analysis of water wave propagation and response to the shore structure due to the construction and implementation of shore boundary, the mathematical formulation of the numerical model is established systematically based on the hybrid Element Method and applied to solving the wave refraction, diffraction and radiation problems for a circular basin, the artificial beach or lagoon in terms of coastal zone development.

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Purification and Characterization of Repressor of Temperate S. aureus Phage Φ11

  • Das, Malabika;Ganguly, Tridib;Chattoraj, Partho;Chanda, Palas Kumar;Bandhu, Amitava;Lee, Chia Yen;Sau, Subrata
    • BMB Reports
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    • v.40 no.5
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    • pp.740-748
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    • 2007
  • To gain insight into the structure and function of repressor proteins of bacteriophages of gram-positive bacteria, repressor of temperate Staphylococcus aureus phage ${\phi}11$ was undertaken as a model system here and purified as an N-terminal histidine-tagged variant (His-CI) by affinity chromatography. A ~19 kDa protein copurified with intact His-CI (~ 30 kDa) at low level was resulted most possibly due to partial cleavage at its Ala-Gly site. At ~10 nM and higher concentrations, His-CI forms significant amount of dimers in solution. There are two repressor binding sites in ${\phi}11$ cI-cro intergenic region and binding to two sites occurs possibly by a cooperative manner. Two sites dissected by HincII digestion were designated operators $O_L$ and $O_R$, respectively. Equilibrium binding studies indicate that His-CI binds to $O_R$ with a little more strongly than $O_L$ and binding species is probably dimeric in nature. Interestingly His-CI binding affinity reduces drastically at elevated temperatures ($32-42^{\circ}C$). Both $O_L$ and $O_R$ harbor a nearly identical inverted repeat and studies show that ${\phi}11$ repressor binds to each repeat efficiently. Additional analyses indicate that ${\phi}11$ repressor, like $\lambda$ repressor, harbors an N-terminal domain and a C-terminal domain which are separated by a hinge region. Secondary structure of ${\phi}11$ CI even nearly resembles to that of $\lambda$ phage repressor though they differ at sequence level. The putative N-terminal HTH (helix-turn-helix) motif of ${\phi}11$ repressor belongs to the HTH -XRE-family of proteins and shows significant identity to the HTH motifs of some proteins of evolutionary distant organisms but not to HTH motifs of most S. aureus phage repressors.