• Title/Summary/Keyword: Break-In

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Historical Geographic Approach to Money, Market and City in Regional Geography (지역지리에서 화폐와 시장, 도시에 관한 역사지리적 접근)

  • Park, Seon-Heui
    • Journal of the Korean association of regional geographers
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    • v.11 no.2
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    • pp.155-168
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    • 2005
  • This study gropes for historical geographic approach to regional research in view of new regional geography. A geographical methodology in regional geography pursues the dialectics of concrete totalities. Regional researches think that social processes interact with the uniqueness of regional characteristics and that region is a historical unit which changes dynamically. Time in regional changes is understood in terms of a dialectics of continuity and break. Transition from feudalism to capitalism is the important period which is captured continuity and break simultaneously. Research objects in this research are money, market and city. Money symbolizes transition to capitalism, and market and city have the importance in transition from feudalism to capitalism In Korea, historical geographic approach to money, market and city both in the era of opening ports and in the Japanese colonial times in Korea are important objects in regional geography. Colonial urban research in view of money and market from the era of opening ports to the Japanese colonial times in Korea is a theme which includes a dialectic of concrete totalities in historical geographic approach in regional geography.

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Drop formation of Carbopol dispersions displaying yield stress, shear thinning and elastic properties in a flow-focusing microfluidic channel

  • Hong, Joung-Sook;Cooper-White, Justin
    • Korea-Australia Rheology Journal
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    • v.21 no.4
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    • pp.269-280
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    • 2009
  • The drop formation dynamics of a shear thinning, elastic, yield stress ($\tau_o$) fluid (Carbopol 980 (poly(acrylic acid)) dispersions) in silicone oil has been investigated in a flow-focusing microfluidic channel. The rheological character of each solution investigated varied from Netwonian-like through to highly non-Newtonian and was varied by changing the degree of neutralization along the poly (acrylic acid) backbone. We have observed that the drop size of these non-Newtonian fluids (regardless of the degree of neutralisation) showed bimodal behaviour. At first we observed increases in drop size with increasing viscosity ratio (viscosity ratio=viscosity of dispersed phase (DP)/viscosity of continuous phase (CP)) at low flowrates of the continuous phases, and thereafter, decreasing drop sizes as the flow rate of the CP increases past a critical value. Only at the onset of pinching and during the high extensional deformation during pinch-off of a drop are any differences in the non-Newtonian characteristics of these fluids, that is extents of shear thinning, elasticity and yield stress ($\tau_o$), apparent. Changes in these break-off dynamics resulted in the observed differences in the number and size distribution of secondary drops during pinch-off for both fluid classes, Newtonian-like and non-Newtonian fluids. In the case of the Newtonian-like drops, a secondary drop was generated by the onset of necking and breakup at both ends of the filament, akin to end-pinching behavior. This pinch-off behavior was observed to be unaffected by changes in viscosity ratio, over the range explored. Meanwhile, in the case of the non-Newtonian solutions, discrete differences in behaviour were observed, believed to be attributable to each of the non-Newtonian properties of shear thinning, elasticity and yield stress. The presence of a yield stress ($\tau_o$), when coupled with slow flow rates or low viscosities of the CP, reduced the drop size compared to the Newtonian-like Carbopol dispersions of much lower viscosity. The presence of shear thinning resulted in a rapid necking event post onset, a decrease in primary droplet size and, in some cases, an increase in the rate of drop production. The presence of elasticity during the extensional flow imposed by the necking event allowed for the extended maintenance of the filament, as observed previously for dilute solutions of linear polymers during drop break-up.

A Study on Multilateral Cooperation for Developing Environmental Technology in Northeast Asia (동북아시아 환경기술개발 다자간 협력에 관한 연구)

  • Kim, Sung-Soo
    • Journal of Environmental Science International
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    • v.23 no.2
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    • pp.231-238
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    • 2014
  • There were many attempts to increase the level of environmental cooperation in Northeast Asia. However, intergovernmental cooperation has not brought a substantial effects so far. This article aims to provide a model for multilateral joint research of environmental technologies. Each field of environmental problem requires a Consortium of joint research team and R & D mechanism. This model emphasizes joint-funding, tax-break for environmental investment and the importance of multilateral contract.

Quality Characteristics of Fish Paste Containing Skate (Raja kenojei) Powder (홍어 분말을 함유한 어묵의 품질 특성)

  • Cho, Hee-Sook;Kim, Kyung-Hee
    • Journal of the East Asian Society of Dietary Life
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    • v.21 no.6
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    • pp.808-813
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    • 2011
  • This study was conducted to promote the utilization of fish paste containing skate (Raja kenojei) powder. The tested concentrations of skate (Raja kenojei) powder were 0, 1, 3, and 5%. The pH levels of the samples ranged from 6.88 to 7.00, whereas moisture contents ranged from 79.51 to 80.35%. Increasing the amount of skate (Raja kenojei) powder in the fish paste tended to decrease lightness (L) in Hunter color value while increasing redness (a) and yellowness (b). All test samples with 3 mm thickness had good flexibility and did not break even after folding four times. Overall, according to the results of our sensory evaluation, fish paste prepared with 3% skate (Raja kenojei) powder was preferred over other fish pastes. Therefore, these results suggest that skate (Raja kenojei) powder can be applied to fish paste for the purpose of high quality and functionality.

A Study on Efficient Approaches for Grasshopper Programming in Architectural Design Process (건축설계과정에서 Grasshopper 프로그래밍의 효율적 접근에 관한 연구)

  • Kim, Minseok
    • Korean Journal of Computational Design and Engineering
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    • v.21 no.4
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    • pp.453-461
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    • 2016
  • The trend of using Grasshopper with Rhino3D actively in architectural design process is recently spreading around the world. Well-known architects and designers such as Zaha Hadid, Patrik Schmacher is famous for using Grasshopper as their main design tool. As a tool for so-called 'Parametric Design', Grasshopper is receiving much attention all over the world. Grasshopper as a visual programming language has an advantage that designers and non-professionals of computer can easily learn it and use it to their works. However, those designers tend to make inefficient approaches with Grasshopper compared to computer programming professionals. Meanwhile, the difference between other programming languages and Grasshopper leads to the need of different approaches from other programming languages. This study aims to propose desired approaches of Grasshopper programming or scripting to be able to break through the inefficient approaches that designer is likely to make, by examining the characteristics of Grasshopper and exploring the appropriate programming approaches for Grasshopper.

Effects of Different Fluid Properties on Velocity and Size of Droplets from Pressure-Swirl Nozzles (유체의 물성치 변화가 압력스월노즐 분무의 속도와 입경에 미치는 영향)

  • Choi, Youn-Chul;Son, Jong-Won;Cha, Keun-Jong;Kim, Duck-Jool
    • Proceedings of the KSME Conference
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    • 2001.06d
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    • pp.909-914
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    • 2001
  • Fluid properties which are most commonly used to evaluate spray atomization characteristics, are important because they affect velocity and size distribution of droplets. The purpose of this study was to incorporate the significant characteristics in atomization process of industrial etching spray and how each of them affects the design of precise pressure-swirl nozzles. The experiment was carried out with different viscosity and density of fluid. The macro characteristics of liquid spray, such as the spray angle and shape were captured by PMAS and the micro characteristics of liquid spray, such as droplet size and velocity were obtained by PDA. The mean velocity and SMD of droplets were measured along axial and radial direction. It was found that the higher viscosity and density resulted in the larger SMD and the lower mean velocity of droplets.

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Several Approaches for Establishing Shanghai as International Metropolitan

  • Liang, Zhang-Shao
    • Proceedings of the KOR-KST Conference
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    • 1996.06a
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    • pp.3-22
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    • 1996
  • To translate the goal of redeveloping Shanghai as one of the international hubs of economy, finance and trade in 2010, the foundation is to be created, and international standing as global city is to be established preliminarily. Transformation of urban functions and approach of "High starting position and jump over" will give impetus to promote Shanghai as an international metropolitan within fairy short period of time. To transform urban functions and translate" High starting position and jump over", certain links which have great impact on Shanghai's rising-up must be handled and normal approach to develop the city must be renovated to reach the goal of establishing an international city. Four strategic approaches as following are explored in this paper : $\bullet$ To transform urban function from industry only to integrated developments. $\bullet$ To break through administrative boundary and expand urban development space. $\bullet$ To develop centralized urban infrastructure framework. $\bullet$ And to erect modern life and culture facilities towards 21st century.

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NUMERICAL SIMULATION OF BOILING PHENOMENA USING A LEVEL-SET METHOD (Level-Set 방법을 이용한 비등현상 해석)

  • Son, G.
    • 한국전산유체공학회:학술대회논문집
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    • 2009.11a
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    • pp.218-222
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    • 2009
  • A level-set (LS) method is presented for computation of boiling phenomena which involve liquid-vapor interfaces that evolve, merge and break up in time, the flow and temperature fields influenced by the interfacial motion, and the microlayer that forms between the solid and the vapor phase near the wall. The LS formulation for tracking the phase interfaces is modified to include the effects of phase change on the liquid-vapor interface and contact angle on the liquid-vapor-solid interline. The LS method can calculate an interface curvature accurately by using a smooth distance function. Also, it is straightforward to implement for two-phase flows in complex geometries. The numerical method is applied for analysis of nucleate boiling on a horizontal surface and film boiling on a horizontal cylinder.

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The Effect of Fluid-Structure Interaction on the Dynamic Response of Reactor Internals (유체-구조물 상호작용이 원자로내부구조물의 동적응답에 미치는 영향)

  • 정명조;박찬국;황원걸
    • Computational Structural Engineering
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    • v.6 no.4
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    • pp.73-82
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    • 1993
  • Investigated in this paper is the effect of fluid-structure interaction between reactor internal components due to their immersion in a confining fluid on the dynamic responses. A non-linear mathematical model is developed for the dynamic analysis of the reactor internals, which includes lumped masses, stiffnesses and hydrodynamic couplings. The hydrodynamic mass matrix which characterizes the fluid-structure interaction is calculated. Also, the equations of motion containing hydrodynamic mass matrix are presented. The responses of the reactor internals due to seismic and pipe break excitations are obtained for the case of with- and without-hydrodynamic couplings and the different response characteristics are investigated.

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Generalized Quantitive Analysis of Hysteresis Processes (히스테리시스 현상의 일반화된 정량화 해석)

  • Hong, Sun-Ki;Lee, Sang-Hoon;Won, Jong-Soo
    • Proceedings of the KIEE Conference
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    • 1991.11a
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    • pp.96-100
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    • 1991
  • In the classical Preisach model for hard magenets, there break out several problems which are the asymmetry and negative domains of the distribution functions and the contradiction of the congruency. In this paper, generalized hysteresis model is proposed by applying the molecular field theory to the classical Preisach model. And it is showed that the problems above are solved by the generalized hysteresis model. The experiments are compared with the simulations and we got acceptible results.

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