• 제목/요약/키워드: Breaking Boundaries

검색결과 32건 처리시간 0.022초

Numerical simulations of two-dimensional floating breakwaters in regular waves using fixed cartesian grid

  • Jeong, Kwang-Leol;Lee, Young-Gill
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제6권2호
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    • pp.206-218
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    • 2014
  • The wave attenuation by floating breakwaters in high amplitude waves, which can lead to wave overtopping and breaking, is examined by numerical simulations. The governing equations, the Navier-Stokes equations and the continuity equation, are calculated in a fixed Cartesian grid system. The body boundaries are defined by the line segment connecting the points where the grid line and body surface meet. No-slip and divergence free conditions are satisfied at the body boundary cell. The nonlinear waves near the moving body is defined using the modified marker-density method. To verify the present numerical method, vortex induced vibration on an elastically mounted cylinder and free roll decay are numerically simulated and the results are compared with those reported in the literature. Using the present numerical method, the wave attenuations by three kinds of floating breakwaters are simulated numerically in a regular wave to compare the performance.

수치조파기에 의해 생성되는 2차원 파도의 유한차분 시뮬레이션 (Finite Difference Simulation of Two-dimensional Waves Generated by Numerical Wavemaker)

  • 이영길;김강신
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2003년도 추계학술대회 논문집
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    • pp.198-203
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    • 2003
  • Unsteady two-dimensional nonlinear waves which are generated by the numerical wavemaker of plunging type are numerically simulated using a finite difference method in rectangular grid system. Two-dimensional Navier-Stokes equations and the continuity equation are used for the computations. Irregular leg lengths and stars are employed near the boundaries of body and free surface to satisfy the boundary conditions. Marker-density function method is adopted for the simulation of wave breaking phenomena, and the computations are carried out with various wave amplitudes and two section shapes of wavemaker. The computation results are compared with other existing computational and experimental results, and the agreement between the experimental data and the computation results is good.

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미세노즐을 통한 액적형성에 관한 수치적 연구 (Numerical Study on Drop Formation Through a Micro Nozzle)

  • 김성일;손기헌
    • 대한기계학회논문집B
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    • 제29권2호
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    • pp.205-213
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    • 2005
  • The drop ejection process from a micro nozzle is investigated by numerically solving the conservation equations for mass and momentum. The liquid-gas interface is tracked by a level set method which is extended for two-fluid flows with irregular solid boundaries. Based on the numerical results, the liquid jet breaking and droplet formation behavior is found to depend strongly on the pulse type of forcing pressure and the contact angle at the gas-liquid-solid interline. The negative pressure forcing can be used to control the formation of satellite droplets. Also, various nozzle shapes are tested to investigate their effect on droplet formation.

방송콘텐츠의 컨버전스 양상과 세계관 설정에 관한 고찰 : '유산슬'과 '펭수'를 중심으로 (A Study on the Convergence Pattern of Broadcasting Contents and the Establishment of World View : Focused on 'Usanseul' and 'Pengsoo')

  • 장해라
    • 한국콘텐츠학회논문지
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    • 제21권7호
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    • pp.20-29
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    • 2021
  • 다플랫폼 미디어 환경이 조성됨에 따라 방송콘텐츠 분야에서는 방송사를 엄격하게 구분 짓거나 타 프로그램의 언급을 조심스러워하던 그동안의 경직된 분위기에서 벗어나 서로 간의 경계를 허물며 컨버전스를 통한 콘텐츠 제작 흐름이 포착되고 있다. 또한 그 방식이 한쪽의 인지도나 프로그램 인기 척도에 따라 수직적으로 행해지는 것이 아니라 상생과 공존의 윈윈 전략으로서 수평적으로 행해졌다는 점에서 상당히 고무적이다. 따라서 본 연구에서는 이와 같은 흐름의 저변에서 급격하게 재편되고 있는 미디어 생태계에 적응하고 살아남기 위해 서로 간의 경계를 초월하는 현상을 포착하고 그 과정에서 다양한 형태로 발현되는 컨버전스 유형과 독보적 가치를 유지하기 위한 세계관 설정에 주목했다. 그리고 이러한 움직임이 두드러지게 나타났던 '유산슬'과 '펭수'를 연구대상으로 선정, 그 초기 양상을 분석하여 레거시 미디어가 기존의 관행을 깨면서까지 선택한 전략들은 무엇이며 이러한 변화들이 앞으로 방송콘텐츠를 기획하는 데에 있어 어떠한 시사점을 갖는지 살펴보았다.

부틀렉 패션의 특성에 대한 연구 (A study on the characteristics of Bootleg fashion)

  • 안세희;김윤
    • 복식문화연구
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    • 제28권1호
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    • pp.30-44
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    • 2020
  • Bootleg fashion emerged from the fashion industry after 2010, and has been used across a range of different genres. However, it has yet to be theoretically established; therefore, this study will explain bootleg fashion as a new genre, which will help in the planning and designing of products within domestic fashion brands. The purpose of this study was to examine the characteristics and internal meaning of bootleg fashion as a recently emerged fashion phenomenon that borrows from other brands without permission. The research methodology included a theoretical literature review of fashion sites and related materials and empirical research using case analysis. Results of the analysis of both characteristics and internal meaning of bootleg fashion suggest the following characteristics: "unauthorized use of symbolic elements," "disorganization of boundaries between fashion," "multiplicity through globalization," and "newness through deconstruction and recombination." Internal meanings derived from the analysis were "parody through symbol," which is seen as "a parody and homage resulting from the unauthorized use of a brand," while "decomposition through disorganization" is seen as a break-up of the boundaries between different fashions from a mainstream-oriented perspective. A juxtaposition of elements was demonstrated by "playfulness through transformation," which showed that such fashion cannot coexist with positional transposition. Finally, "spread as a cultural phenomenon" was derived through the diffusion through digital media with DIY culture. As such, bootleg fashion has been reborn as an innovative fashion genre, breaking the taboo of the illegitimate from the past and demonstrating new endeavors.

타자성의 담론으로 본 F.O.A 건축 공간생성 원리에 관한 연구 (A Study on the Principle of F.O.A Construction Space Creation Viewed from the Discussion of Otherness)

  • 이지연
    • 한국실내디자인학회논문집
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    • 제17권3호
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    • pp.86-93
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    • 2008
  • The purpose of this study is to find out how the otherness philosophy reveals itself in the principle of F.O.A construction space creation. The traditional philosophy of totality is self-centered and thoughts are based on the subject. It couldn't escape from the world associated with the self, and has subordinated the other to the main body. But the philosophy of otherness transcends the subject, to the open, creative way of thinking which acknowledges deconstruction, decentralization, and non-hierarchy. This is very similar to contemporary architecture, which pursuits change, and also to the current state of society. In construction by the construction group F.O.A, which is doing notable activity this generation, there is an attempt to transcend the fixed subject which is seen in the otherness discussion, and realize recategorization by overcoming the boundaries of subject and object. First, by the realization of landscape architecture using a topographical folding technique, boundaries of the subject and object are demolished in the relationship of the landscape construction, and recategorization. Second, by breaking up the meaning of the surface which is a visual and physical boundary for both the internal and external, recategorization is being done. Third, by making the boundary between the interior and exterior indistinct, cognitive threshold is dissolved, and the relationship between the subject and object is being recategorization. In conclusion, we can see that the many recategorization phenomenons that are happening in the F.O.A construction show the otherness that escapes from the conventional and stationary relationship, and recognizes each other at the same time, forming new relationships.

2차원 Beach에서 쇄파의 시뮬레이션을 위한 수치계산기법의 비교 (Comparison of Numerical Methods for Two-dimensional Wave Breaker on a Plane Beach of Constant Slope)

  • 정광열;이영길
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2004년도 춘계 학술대회논문집
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    • pp.119-125
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    • 2004
  • Unsteady nonlinear wave motions on the free surface over a plane beach of constant slope are numerically simulated using a finite difference method in rectangular grid system. Two-dimensional Navier-Stokes equations and the continuity equation are used for the computations. Irregular leg lengths and stars are employed near the boundaries of body and free surface to satisfy the boundary conditions. Also, the free surface which consists of markers or segments is determined every time step with the satisfaction of kinematic and dynamic free surface conditions. Moreover, marker-density method is also adopted to allow plunging jets impinging on the free surface. The second-order Stokes wave theory and solitary wave theory are employed for the generation of waves on the inflow boundary. For the simulation of wave breaking phenomena, the computations are carried out with the plane beach of constant slope in surf zone. The results are compared with each other. The marker-density method is better then the hybrid method. Also they are compared with other existing experimental results. The Agreement between the experimental data and the computation results is good.

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버블 잉크젯에서의 기포성장 및 액적분사에 관한 수치적 연구 (Numerical Study on Bubble Growth and Droplet Ejection in a Bubble Inkjet Printer)

  • 서영호;손기헌
    • 대한기계학회논문집B
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    • 제30권11호
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    • pp.1107-1116
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    • 2006
  • The droplet ejection process driven by an evaporating bubble in a thermal inkjet printhead is investigated by numerically solving the conservation equations for mass, momentum and energy. The phase interfaces are tracked by a level set method which is modified to include the effect of phase change at the interface and extended for multiphase flows with irregular solid boundaries. The compressibility effect of a bubble is also included in the analysis to appropriately describe the bubble expansion behaviour associated with the high pressure caused by bubble nucleation. The whole process of bubble growth and collapse as well as droplet ejection during thermal inkjet printing is simulated without employing a simplified semi-empirical bubble growth model. Based on the numerical results, the jet breaking and droplet formation behaviour is observed to depend strongly on the bubble growth and collapse pattern. Also, the effects of liquid viscosity, surface tension and nozzle geometry are quantified from the calculated bubble growth rate and ink droplet ejection distance.

Experimental approach to evaluate weathering condition of granite using electrical resistivity

  • Oh, Tae-Min;Cho, Gye-Chun;Son, Thai An;Ryu, Hee-Hwan;Lee, Changho
    • Geomechanics and Engineering
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    • 제8권5호
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    • pp.675-685
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    • 2015
  • Weathering is the breaking/cutting down process of rocks due to physical and chemical processes in natural as well as artificial environment including $CO_2$ injection for storage in the sediment, or natural resource recovery process. This study suggests an alternative method to estimate the degree of weathering for granites. A series of laboratory and field experiments are performed to measure electrical resistivities on various rock samples experienced different degrees of weathering and their residual soils under different saturation conditions. It is found that the normalized electrical resistivity increases with a decrease in water absorption and the saturation. Simple boundaries are suggested to identify the weathering degree of granites, based on limited data. Field test results for three sites confirm that the suggested method could be estimated well the degree of weathering of granites compared with the other methods suggested previously. Although further research is required, this study suggests that an electrical resistivity could be an effective approach to estimate the degree of weathering of granites compared with the other methods suggested previously.

A Numerical Solution. Method for Two-dimensional Nonlinear Water Waves on a Plane Beach of Constant Slope

  • Lee, Young-Gill;Heo, Jae-Kyung;Jeong, Kwang-Leol;Kim, Kang-Sin
    • Journal of Ship and Ocean Technology
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    • 제8권2호
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    • pp.61-69
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    • 2004
  • Unsteady nonlinear wave motions on the free surface over a plane beach of constant slope are numerically simulated using a finite difference method in rectangular grid system. Two-dimensional Navier-Stokes equations and the continuity equation are used for the computations. Irregular leg lengths and stars are employed near the boundaries of body and free surface to satisfy the boundary conditions. Also, the free surface which consists of markers or segments is determined every time step with the satisfaction of kinematic and dynamic free surface conditions. Moreover, marker-density method is also adopted to allow plunging jets impinging on the free surface. The second-order Stokes wave theory is employed for the generation of waves on the inflow boundary. For the simulation of wave breaking phenomena, the computations are carried out with the plane beach of constant slope in surf zone. The results are compared with other existing experimental results. Agreement between the experimental data and the computation results is good.