• Title/Summary/Keyword: 개방 경계조건

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A Case Study of Community without Propinquity : focused on Topgol Comic Book Space in Goesan, Chungbuk (근접성 없는 공동체의 사례 연구 - 충북 괴산 탑골 만화방을 대상으로 -)

  • Lee, Jung-Min;Lee, Man-Hyung;Hong, Sung-Ho
    • Journal of the Korean association of regional geographers
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    • v.22 no.3
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    • pp.655-665
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    • 2016
  • The meanings and roles of community have been changed. Traditional community theories hinged on the neighborhood have been threatened by the alternative concept of 'communities without propinquity'. Embracing unprecedented development of transportation, information and communication technologies, Propinquity of community has not been a precondition. This paper reviews the development of community theories with a frame of 'communities without propinquity'. Furthermore, applying social network analysis(SNA) approaches, it explores the communality of Topgol Comic Book Space, located in Goesan, Chungbuk and examines spatial characters. Visitors' networks of Topgol Comic Book Space builda up national coverage and expands. It functions as a field of testing various activities without explicit 'fixed purpose'. The case exemplifies a community, continuously enlarging the spatial and social boundaries, performing a series of activities, and connecting both the outside and the local.

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A Numerical Modeling of the East sea circulation (동해 순환의 수치모델)

  • Seung, Young-Ho;Kim, Kyun
    • 한국해양학회지
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    • v.28 no.4
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    • pp.292-304
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    • 1993
  • The east Sea circulation is numerically modeled with refined grid resolution elaborated open boundary condition, and by directly imposing the measured surface temperature and salinity typical the east Korean Warm current are clearer than those in previous works. among others, The Ulleung warm Water and the Intermediate Water of minimum salinity are nicely reproduced. The latter is formed in the northern/northwestern coastal region in winter and is advocated southward by strong under-current. the former is associated with a locally generated anti-cyclonic gyres. The model indicates strong seasonal variation of Nearshore Current along the Japanese coast from wintertime barotropic to summertime baroclinic structures. the associated strong reversed under-cur-rent in summer is not well understood. Global circulation pattern is characterized by two regions of cyclonic and anti-cyclonic gyres in the north and south, respectively. The presence of these gyres indicates importance of local dynamics in East Sea circulation. This model, however, does not completely resolve the problem of overshooting of the East Korean Warm current.

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Numerical Simulation for Behavior of Tidal Elevation and Tidal Currents in the South Sea (남해안의 조위 및 조류거동 수치모의)

  • Kwon, Seok-Jae;Kang, Tae-Soon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.19 no.3
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    • pp.253-265
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    • 2007
  • This study applied the previous results of the NAO model, a tidal correction model, to the open boundary condition for the behavior of tidal elevation and tidal currents in the South Sea. This study used the EFDC model considering the wetting and drying problem and using the $\sigma-coordinate$ as a vertical coordinate and generated two mesh cases of the constant grid size of 2.0 km and the variable grid size of $0.5\sim2.0km$. The numerical results for the tides showed that the predicted results were in quite good agreements with the observational data acquired from the tidal stations of the NORI. The predicted tides were observed to propagate from the east area to the west area in the South Sea. The verification results reveal that the numerical results are more correlated with the measured tidal data as the grid size decreases. The grid size of 2 km results in proper simulation of tidal currents in wide waterway and offshore area whereas the numerical results from the grid size of 0.5 km tend to somewhat underestimate the tidal currents affected by narrow waterway and topography in inner-bay.

Numerical Modeling of Ebb-Dominant Tidal Flow in the Mokpo Coastal Zone (목포해역 낙조류 우세현상의 수치모의)

  • Jung, Tae-Sung;Choi, Jong-Hwa
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.22 no.5
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    • pp.333-343
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    • 2010
  • In Mokpo coastal zone, the characteristics showing ebb-dominant tidal flow was confirmed by analysis of observed tide and tidal currents, Physical factors occurring ebb-dominant flow were reviewed. Influence of critical depth for drying, bottom shear stress, coastal reclamation, tidal amplitude, nonlinear tide, and eddy viscosity on the change of ebb-dominant flow was investigated by applying a two-dimensional circulation model. The simulation results for a variety of conditions showed that eddy viscosity and critical depth for drying does little or no impact on the generation of asymmetric flow. Strong bottom friction stress makes ebb-dominant flow clearly. Change of tidal flat into land swells ebb- dominant flow, and change of tidal flat into sea disappears ebb-dominant flow. Nonlinear tides play a decisive role in the generation of asymmetrical tidal flow. Non-linear tides should be included in the open boundary conditions of hydrodynamic modeling in the Mokpo coastal zone.

Numerical Modeling of Changes in Tides and Tidal Currents Caused by Embankment at Chonsu Bay (천수만 방조제 건설로 인한 조석현상 변화)

  • 소재귀;정경태;채장원
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.10 no.4
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    • pp.151-164
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    • 1998
  • Changes in tides and tidal currents in Chonsu Bay caused by the construction of Seosan A and B reclamation regions have been investigated using a depth-integrated two-dimensional tidal model. Three water level recorders were deployed for about one month and used for the specification of the open boundary condition. The computed currents were found to be in a good agreement with the measurements at two stations within Chonsu Bay. Comparison of the absolute velocities computed with the conditions before and after the embankment clearly shows that the reduction in tidal current amplitude is evident throughout the bay and the magnitude of the reduction increases to the north. Calculation shows that the embankment has advanced the time of drying at the northern part of the bay by about 51 minutes and has increased the exposure time by about 23 minutes. The high water time has advanced by about 1 hour, lowering the high water level by about 15 cm.

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Calibration and Verification of a Hydrodynamic Model in Chunsu Bay and Adjacent Coastal Water (천수만과 인근연안에서 수역학모델의 보정 및 검증)

  • Kyeong Park;Jeong Hwan Oh
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.10 no.3
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    • pp.109-119
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    • 1998
  • A horizontal tow-dimensional version of POM (Princeton Ocean Model) was modified in representing the bottom friction and the open boundary conditions. To simulate the flooding and drying of intertidal flats, a wetting-and-drying scheme was incorporated into the model. The model then was applied to the Chunsu Bay and its adjacent coastal water. Only the water movement due to tides, the dominant forcing in the study area, was considered. This presents the procedure and the results of model calibration and verification for the Chunsu Bay system. The model was calibrated, using the average tidal characteristics in Tide Tables, for the amplitudes and the phases of tidal waves throughout the modeling domain. Calibration results showed that the model gave a good reproduction of tidal waves. The calibrated model was verified using the time-series measurements of surface elevation and current velocity in the summer of 1995. The model reproduced the tides currents very well. calibration and verification results demonstrated that the model is capable of reproducing the tidal dynamics in the Chunsu Bay system.

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The Experimental Analysis of the Effect of Wind Load on the Stability of a Container Crane (풍하중이 컨테이너 크레인 안정성에 미치는 영향의 실험적 해석)

  • Lee Seong-Wook;Shim Jae-Joon;Han Dong-Seup;Han Geun-Jo;Kim Tae-Hyung;Hwang Kyu-Seok
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2005.10a
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    • pp.229-234
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    • 2005
  • This study was carried out to analyze the effect of wind load on the stability of a 50ton container crane using wind tunnel test and provide a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load at 75m/s wind velocity is applied on a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Effect type atmospheric boundary-layer wind tunnel with $11.52m^2$ cross-section area. Each directional drag and overturning moment coefficients were investigated and uplift forces at each supporting point due to the wind load were analyzed.

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Effect of Nonlinear Terms on the Generation of $M_2$ Tide Residual Elevation and $M_4$ Tide in the Yellow Sea and the East China Sea (황해ㆍ동중국해의 $M_2$ 조석 잔차위 및 $M_4$ 조석 생성에 대한 비선형항의 영향)

  • 이종찬;정경태;최병호
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.8 no.2
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    • pp.137-145
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    • 1996
  • Effects of nonlinear terms on the generation of M$_2$ tide residual elevation and M$_4$ tide in the Yellow Sea and the East China Sea are investigated using a depth-integrated two-dimensional nonlinear M$_2$tidal model. The model domain (117$^{\circ}$E-130$^{\circ}$E, 24$^{\circ}$N-41$^{\circ}$N) covers the whole region of the Yellow Sea and the East China Sea with grid resolution of 1/6$^{\circ}$ in longitude and 1/8$^{\circ}$in latitude. A radiational boundary condition is used along the open boundaries. Calculations show that advection terms yield negative residual elevation, while shallow-water terms in continuity equation yield positive residual elevation. The contribution of both advection terms and shallow-water terms to tile generation of the M$_4$ constituent is more than 90 percents, but that of quadratic bottom friction terms to the M$_4$ constituent is comparatively small.

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Calculations of Storm Surges, Typhoon Maemi (해일고 산정 수치모의 실험, 태풍 매미)

  • Lee, Jong-Chan;Kwon, Jae-Il;Park, Kwang-Soon;Jun, Ki-Cheon
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.1
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    • pp.93-100
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    • 2008
  • A multi-nesting grid storm surge model, Korea Ocean Research and Development Institute-Storm surge model, was calibrated to simulate storm surges. To check the performance of this storm surge model, a series of numerical experiments were explored including tidal calibration, the influence of the open boundary condition, the grid resolutions, and typhoon paths on the surge heights using the typhoon Maemi, which caused a severe coastal disasters in Sep. 2003. In this study the meteorological input data such as atmospheric pressure and wind fields were calculated using CE wind model. Total 11 tidal gauge station records with 1-minute interval data were compared with the model results and the storm surge heights were successfully simulated. The numerical experiments emphasized the importance of meteorological input and fine-mesh grid systems on the precise storm surge prediction. This storm surge model could be used as an operational storm surge prediction system after more intensive verification.

A Study on the Estimation of the Structural Stability of a Container Crane according to the Change of the Boom Shape using Wind Tunnel Test (풍동실험을 이용한 붐 형상 변화에 따른 컨테이너 크레인 구조 안정성 평가에 관한 연구)

  • Lee Seong-Wook;Han Geun-Jo;Han Dong-Seop;Kim Tae-Ryung
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.06b
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    • pp.311-316
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    • 2006
  • This study was carried out to analyze the effect of wind load on the structural stability of a container crane according to the change of the boom shape using wind tunnel test and provided a container crane designer with data which can be used in a wind resistance design of a container crane assuming that a wind load at 75m/s wind velocity is applied on a container crane. Data acquisition conditions for this experiment were established in accordance with the similarity. The scale of a container crane dimension, wind velocity and time were chosen as 1/200, 1/13.3 and 1/15. And this experiment was implemented in an Eiffel type atmospheric boundary-layer wind tunnel with $11.25m^2$ cross-section area. Each directional drag and overturning moment coefficients were investigated and uplift forces at each supporting point due to the wind load were analyzed.

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