• Title/Summary/Keyword: the backward selectivity

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Korean welfare regime in the conservative administration, 2008-2016 (역진적 선별성의 지속과 확장성의 제약, 2008~2016: 이명박·박근혜 정부시기 한국복지체제의 특성)

  • Yoon, Hongsik
    • 한국사회정책
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    • v.25 no.4
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    • pp.163-198
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    • 2018
  • This study analyzed the change of the Korean welfare regime during the conservative government. It is clear that the welfare expanded during the conservative government, but this expansion was the process of realizing the constraint of expansion that reduces future welfare expenditure in Korea. In addition, as the public welfare centered on social insurance expanded after 10 years of liberal government, the backward selectivity of the Korean welfare regime strengthened in the conservative administration. Expanding social insurance itself does not reinforce the backward selectivity of the Korean welfare regime. However, the industrial structure created by the export-led growth system has intensified the fragmentation of the labor market, and expanding social insurance designed based on regular workers under these conditions has forced the backward selectivity of the social security system. It is for this reason that the backward selectivity has been reinforced during the conservative government.

Penetrating behavior of target prawns (Sicyonia penicillata) contacting netting panels in an experimental water tunnel

  • KIM, Yonghae;GORDON, Malcolm S.
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.54 no.3
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    • pp.193-203
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    • 2018
  • Capture efficiencies of commercial shrimp trawls may improve if their designs took into better account behavioral responses of wild shrimp to approaching cod-end of the trawls. Here we report results of water tunnel-based experimental studies of responses of wild California target prawns to several different near-realistic netting configurations over a range of water velocities (0.3-0.7 m/s). Netting panels were oriented at parallel to water flows (FP) on the bottom of test section, vertical (VT) or diagonal sloping backward (DG), bottom to top. Behavioral responses were recorded by video camera and analyzed frame by frame. Measured responses included rates of penetrating through netting by behavioral features and tail-flip frequencies. Frequencies of prawn passing through the nets increased with flow speed for both orientations and were higher at given speeds for sloped nets. Other behavioral features (e.g., passage head-or tail-first) also varied significantly with water velocities and netting orientation. Interactions of penetrating rates between netting orientations and flow speeds also were significantly dependent, except for prawn size. Additional studies are needed of other shrimp species and at higher water velocities more similar to actual field operations using trawls to improve size selectivity.

A Parametric Study of Pervaporation-facilitated Esterification (전산모델링을 통한 투과증발-촉진 에스테르화 반응에 대한 연구)

  • Yeom, C.K.;Choi, Seung-Hak;Park, You-In;Chang, Sung-Soon
    • Membrane Journal
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    • v.17 no.2
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    • pp.146-160
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    • 2007
  • A parametric study on pervaporation-facilitated esterification was performed by using a practical model based on non-perfect separation through membrane which is not perfectly permselective to water. Thus, membrane selectivity as well as membrane capability to remove water should be taken into account in establishing the simulation model to explain how the membrane separation influence the esterification reaction process. It was shown by simulation that in the reaction systems with non-perfect separation, the permeation of reactants which are acid or/and alcohol retards the reaction by inducing the backward reaction so that reaction conversion curve is located between a reaction system coupled with pervaporation process having a perfect permselectivity to water and a reaction system without pervaporation process. The volume change of reaction system occurs as a result of the permeation through the membrane. The reaction volume change which can be characterized by the reaction ratio of $r_{\Psi}\;to\;r_{{\Psi}=1}$ affects reaction kinetics by concentrating reactants and products, respectively, with different extent with time; reactant-concentrating effect is dominant during the initial stage of reaction, resulting in facilitating the reaction, and then product-concentrating effect is exerted more on reaction, causing to slow down the reaction. When pervaporative dehydration is applied to the reaction system plays an important role in the reaction as well. The effect of timing to impose pervaporation on reaction system affected the reaction kinetics in terms of reaction rate and reaction conversion. A relationship was derived to explain membrane unit capacity and reaction parameters that will be used as a design tool to determine membrane unit capacity at a given reaction conditions or reaction parameters at a membrane unit capacity.