• Journal of architectural history
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• v.30 no.4
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• pp.79-90
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• 2021

Since its construction in the late 14th century, Hanyangdoseong had been carried out three major repairs and reconstructions during the 500 years of the Joseon Dynasty. In addition to the large-scale construction, small-scale construction continued until King Gojong era. In particular, in the 18th century, systematic construction management was implemented by the craftsmen and the military participated in the renovation of Hanyangdoseong in earnest, and the construction methods also developed rapidly. In the early 18th century, new construction techniques were attempted in various sections of the reconstruction work, and gradually became a common technology for repairing Hanyangdoseong in the late 18th century. The purpose of this study is to examine the characteristics and period of changes in the 18th century's construction technique, when the rapid development of Hanyangdoseong took place. To this end, the excavation results related to Hanyangdoseong, the remaining city wall, and the inscribed stones were used to identify and demonstrate the characteristics and change of the construction method.

• Journal of the KSME
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• v.22 no.4
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• pp.262-270
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• 1982

머지않은 장래에는 이러한 초컴퓨터와 신기술들이 유체역학의 주요한 발전을 주도하고, 오랫동안 취급하지 못하였던 난류유통도 해석할 수 있을 것이며, 복잡한 비행기 형상의 외부 유통도 발 전된 형체막형화 기법과 격자발생법 및 그래픽 기술을 이용하여 손쉽게 계산될 것이다. 금세기 말까지의 공기역학의 발전은 주로 공기의 탄성효과를 고려한 비정상압축성 공기역학에서 이루 어질 것이다.

• Journal of computational fluids engineering
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• v.18 no.3
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• pp.79-86
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• 2013

Preconditioned compressible Navier-Stokes equations are solved for almost incompressible flows. Unstructured meshes are utilized for spatial discretization of complex flow domain. Effectiveness of the current preconditioning algorithm, with respect to various Reynolds numbers and Mach numbers, is demonstrated by the solution of canonical problems for incompressible flows, e.g. driven cavity flows.

• Korean Journal of Heritage: History & Science
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• v.46 no.4
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• pp.126-143
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• 2013

Myeonghwalsanseong Fortress and Namsansinseong Fortress in Gyeongju are one of the few that have accurate records of when and who constructed the structures. Based on the monument commemorating the construction of Myeonghwalsanseong Fortress and the construction technique and structure of the fortresses confirmed through excavation survey, it can be induced that Myeonghwalsanseong Fortress was built prior to the 7th century. Meanwhile, Namsansinseong Fortress is believed to have been erected in 679, with the exception of one part of the wall found in the northwestern valley that was built during the first construction period of 591. Referring to the construction method of these fortresses in the royal capital, Gyeongju, various recentlystudied fortresses were reviewed to estimate the construction periods. As a result, Haman Seongsansanseong Fortress, which takes similar form with Myeonghwalsanseong Fortress, is believed to have been built during the mid-6th century based on the construction method and supplementary work method(i.e. Bochuk). Yangdongsanseong Fortress in Gimhae and Singisanseong Fortress, similar in their construction method, are also believed to be from the same period. Meanwhile, Jusanseong Fortress of Goryeong, despite the similar construction technique used, the construction technique used for Bochuk or limited Bochuk imply a time gap. Separately, most of the remaining walls of Namsansinseong Fortress appear to date back to the additional construction period, and Sageunsanseong Fortress in Hamyang and Dadaesanseong Fortress in Geoje that show similar construction method are set for the same period. Such conclusion was drawn from straight layer piling using the refined rectangular stones found in the fortress and the supplementary part remaining thereof. In addition, the study discovered a cross-section triangular water hole at Yangdongsanseong Fortress in Gimhae and Sageunsanseong Fortress in Hamyang and the trace of wooden fences constructed before the construction of stone-wall, reaping outcomes rarely found in this region.

• 한국전산유체공학회:학술대회논문집
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• 1995.10a
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• pp.113-117
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• 1995

Viscous analysis on incompressible flows is performed using unstructured triangular meshes. A two-dimensional and axisymmetric incompressible Navier-Stokes equations are solved in time-marching form by artificial compressibility method. The governing equations are discretized by a cell-centered based finite-volume method. and a centered scheme is used for inviscid and viscous fluxes with fourth order artificial dissipation. An explicit multi-stage Runge-Kutta method is used for the time integration with local time stepping and implicit residual smoothing. Convergence properties are examined and solution accuracies are also validated with benchmark solution and experiment.

• Geotechnical Engineering
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• v.13 no.3
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• pp.5-20
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• 1997

A governing equation of uncoupled three dimensional finite strain theory of consolidation is presented. This equation is suitable for relatively thick layers, possessing large strain, non-linear material property, and variable permeability. A special numerical solution procedure has to be adopted for the finite difference scheme because the solution is not stable in using Forward-Time Centered-Space (FTCS) method and the governing equation is highly non-linear. The solution is capable of predicting settlement with respect to time. The results predicted by the developed method of analysis have been compared with those of experimental tests on different types of highly compressible soils with vertical wick drain. The uncoupled three dimensional finite strain theory of consolidation appears to predict settlement behavior well. A detailed comparison shows good agreement in terms of total settlement, and reasonable agreement with respect to time.

• Tunnel and Underground Space
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• v.14 no.3
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• pp.229-240
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• 2004

Coastal aquifers may serve as major sources fur freshwater. In many coastal aquifers, intrusion of seawater has become one of the major constraints imposed on groundwater utilization. The management of groundwater in coastal acquifers means making decision as to the pumping rate and the spatial distribution of wells. Several numerical techniques for flow and solute transport simulation can provide the means to achieve this goal. As a basic study to predict the intrusion of seawater in coastal phreatic aquifers, the coupled flow and solute transport analysis was conducted by use of the 3-D finite element code, SWICHA. In order to understand how the location and the shape of freshwater-seawater transition zone were affected by the boundary conditions and hydrogeologic variables, parametric study was carried out.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.3
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• pp.210-217
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• 2011

Evolution of tip vortex generated by a model rotor blade which has a symmetric blade section has been investigated by use of the laser doppler anemometry. Swirl and axial velocity components of tip vortex were measured by the phase averaging technique within one revolution of a rotor blade. It was found that tip vortex becomes matured until 27 degrees and diffuses afterwards with diffusing rate becoming slower compared to the case of the asymmetric blade section, but the tip loss was expected to become more substantial. Swirl velocity components were well fit to n=2 model of Vatistas within measured wake ages, showing the self-similarity exists for the swirl velocity components. The axial components were followed with Gaussian profiles, but had much higher peak values than those of the symmetric blade section.

• Journal of the Korean GEO-environmental Society
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• v.7 no.3
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• pp.5-19
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• 2006

The secondary consolidation settlement of soft clay is generally very little compared to the total settlement and occurs very slowly during long-term period. However the secondary consolidation settlement is comparatively large amount in organic and heavily compressed clay and is a very important engineering factor. In order to reduce residual settlements in reclaimed soft ground, the preloading method is often used. In this study, in order to determine reasonable long-term settlements of large reclaimed site, laboratory incremental loading consolidation tests and surcharging consolidation tests are performed. Sampling was done at Incheon area of west coast and Gwangyang area of south coast in Korea. The characteristics of secondary consolidation have obtained through laboratory tests and analyzed systematically to predict long-term settlements. Additionally, the location data and laboratory test results are correlated by using GIS(geographic information system). The secondary consolidation settlement of the site was predicted based on D/B and the operation technique and estimation technique of space of GIS.

• Journal of the Korean Geotechnical Society
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• v.27 no.9
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• pp.13-24
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• 2011

The renowned Terzaghi's one-dimensional consolidation theory is not applicable to quantification of time-rate settlement for highly deformable soft clays such as dredged soil deposits. To deal with this special condition, a non-linear finite strain consolidation theory should be adopted to predict the settlement of dredged soil deposits including self-weight and surcharge-induced consolidation. It is of importance to determine the zero effective stress void ratio ($e_{00}$), which is the void ratio at effective stress equal to zero, and the relationships of void ratio-effective stress and of void ratio-hydraulic conductivity for characterizing non-linear finite strain consolidation behavior for deformable dredged soil deposits. The zero effective stress void ratio means a transitional status from sedimentation to self-weight consolidation of dredged soils. In this paper, laboratory procedures and equipments are introduced to measure such key parameters in the non-linear finite strain consolidation analysis. In addition, the non-linear finite strain consolidation parameters of the Incheon clay and kaolinite are evaluated with the aid of the proposed methods in this paper, which will be used as input parameters for the non-linear finite strain consolidation analyses being performed in the companion paper.