Contextual Influences on Women's Identities and Leadership Styles

NAH, YoonKyeong Ewha Womans University Press 2003 Asian Journal of Women's Studies(AJWS) Vol.9 No.4

This article is part of a study on Korean women leaders' learning processes. It describes and analyzes the self-identification processes and leadership styles of women leaders in male-dominated professions. These women's ways of identifying themselves and of leading others challenge the existing mode of women's identities and leadership styles as being relation-conscious. This study therefore proposes the view that there may be other leadership styles adopted by women leaders based on their varied contexts and life experiences.

The fibrogenic process and the unleashing of acute-on-chronic liver failure

Guillermo Nahúm López-Sánchez,Mayra Dóminguez-Pérez,Misael Uribe,Natalia Nuño-Lámbarri 대한간학회 2020 Clinical and Molecular Hepatology(대한간학회지) Vol.26 No.1

Acute-on-chronic liver failure (ACLF) is a life-threatening condition characterized by a rapid deterioration of previously well-compensated chronic liver diseases. One of the main obstacles in ACLF is the lack of knowledge of the pathogenesis and specific broad-spectrum treatments. An excessive systemic inflammatory response has been proposed to explain the pathogenesis of ACLF; this hypothesis involves stellate cells, which are implicated in many liver homeostatic functions that include vitamin A storage, regulation of sinusoidal blood flow, local inflammation, maintenance of the hepatocyte phenotype and extracellular matrix remodeling. However, when there is damage to the liver, these cells are the main target of the inflammatory stimulus, as a result, the secretion of the extracellular matrix is altered. Activated hepatic stellate cells raise the survival of neutrophils by the stimulation of granulocytes colonies and macrophages, which exacerbates liver inflammation and promotes damage to hepatocytes. Elevation of pathogen-associated molecular patterns is related to liver damage by different pathophysiological mechanisms of decompensation, showing ballooning degeneration and cell death with a predominance of cholestatic infection. Moreover, patients with ACLF present a marked elevation of C-reactive protein together with an elevation of the leukocyte count. Chronic liver disease is a complex pathological state with a heterogeneous pathophysiology in which genetic factors of the host and external triggers interact and culminate in hepatic insufficiency. The better understanding of such interactions should lead to a better comprehension of the disease and to the discovery of new treatment targets that will make acute decompensations preventable and even decrease mortality.

Marinifilum fragile gen. nov., sp. nov., isolated from tidal flat sediment

Na, H.,Kim, S.,Moon, E. Y.,Chun, J. Microbiology Society 2009 International journal of systematic and evolutiona Vol.59 No.9

<P>A facultatively anaerobic, moderately halophilic, Gram-negative, filamentous bacterium, designated JC2469T, was isolated from tidal flat sediment in Korea. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolate belonged to the phylum Bacteroidetes and its closest taxonomic relative was Cytophaga fermentans NCIMB 2218T (89.6% sequence similarity). Cells appeared as filaments during exponential growth, but became fragmented to rods at stationary phase. Spherical cells were also observed in aged cultures. Strain JC2469T contained iso-C15:0 (56.2%) and MK-7 as the predominant fatty acid and respiratory quinone, respectively. On the basis of evidence from this polyphasic study, the isolate showed substantial differences from other genera. The phylogenetic and physiological data of the present study strongly suggest that the isolate represents a novel genus and species, for which the name Marinifilum fragile gen. nov., sp. nov. is proposed. The type strain of Marinifilum fragile is JC2469T (=IMSNU 14138T=KCTC 22488T=JCM 15579T).</P>

One-dimensional coolability and concrete ablation analysis of volumetrically heat-generating debris bed

Na, H.,Lee, H.J.,Kwon, S.,Kim, S.J.,Kim, J. Pergamon Press ; Elsevier Science Ltd 2017 Annals of nuclear energy Vol.106 No.-

<P>We present a preliminary study on the feasibility of the pre-flooded cavity strategy for ex-vessel cooling of APR1400 NPPs. Fragmented particles form a porous debris bed, so understanding the heat transfer mechanism in a porous medium and its critical heat flux is essential to assess the coolability of the debris bed. An one-dimensional dryout heat flux model of porous medium is derived from a water and vapor momentum equation for porous medium, two-phase permeability modifications and the correlation between capillary pressure and liquid saturation. The developed model is validated by comparing dryout heat flux data of DEBRIS, STXY, POMECO and COOLOCE tests. STXY BED, POMECO BED-5 and COOLOCE-8 BED are made to reflect the particle size distribution results of the melt fragmentation tests such as FARO, CCM, MIRA and DEFOR. We analyze the ex-vessel coolability by assuming that these three beds represent debris beds in actual accidents. In addition, one-dimensional coolability analysis is conducted for three cases of cylinder shape debris bed at containment pressures of 1-5 bar. Based on these, one-dimensional ablation concrete depth analysis for the three cases of debris shape and the three kinds of the debris beds of APR1400 NPPs is conducted. As a result, if fragmented particles are distributed evenly and the POMECO BED-5 or STXY BED like debris bed is formed in the cavity, the debris bed coolability is so good that ablation depth is negligible or less than the thickness of sacrificial concrete. Even if the COOLOCE-8 BED like debris bed is formed, the integrity of the containment is kept during ex-vessel cooling if the containment pressure is maintained 3 bar or more. However, if the solidified particles spread only in a particular area, the leak tightness of containment building could not be maintained in the ex vessel cooling process. Because solidified particles lose their fluidity, so it is questionable that all of them are distributed uniformly in the cavity. Therefore, a further research is required on how fragmented particles are distributed in pre-flooded cavities to validate the pre-flooding strategy of APR1400 NPPs. (C) 2017 Elsevier Ltd. All rights reserved.</P>

An Exp Model with Spatially Adaptive Regularization Parameters for Multiplicative Noise Removal

Na, H.,Kang, M.,Jung, M.,Kang, M. Springer Science + Business Media 2018 Journal of scientific computing Vol.75 No.1

<P>This article proposes a total variation (TV) based model with local constraints for heavy multiplicative noise removal. The local constraint involves multiple local windows rather than one local window as in Chen and Cheng (IEEE Trans Image Process 21(4):1650-1662, 2012), and the proposed model is an extension model of Lu et al. (Appl Comput Harmon Anal 41(2):518-539, 2016) that incorporates a spatially adaptive regularization parameter, which enables us to handle heavy multiplicative noise as well as to sufficiently denoise in homogeneous regions while preserving small details and edges. In addition, convergence analysis such as the existence and uniqueness of a solution for our model is also provided. We also derive an optimization algorithm from the first-order optimality characterization of our model. Furthermore, we utilize a proximal linearized alternating direction algorithm for efficiently solving our subproblem. Numerical results are shown to validate the effectiveness of our model, with comparisons with several existing TV based models.</P>

Analysis of roll-stamped light guide plate fabricated with laser-ablated stamper

Na, H.,Hong, S.,Kim, J.,Hwang, J.,Joo, B.,Yoon, K.,Kang, J. Elsevier Advanced Technology 2017 Optics and laser technology Vol.97 No.-

LGP (light guide plate) is one of the major components of LCD (liquid crystal display), and it makes surface illumination for LCD backlit. LGP is a transparent plastic plate usually produced by injection molding process. On the back of LGP there are micron size patterns for extraction of light. Recently a roll-stamping process has achieved the high mass productivity of thinner LGPs. In order to fabricate optical patterns on LGPs, a fabricating tool called as a stamper is used. Micro patterns on metallic stampers are made by several micro machining processes such as chemical etching, LIGA-reflow, and laser ablation. In this study, a roll-stamping process by using a laser ablated metallic stamper was dealt with in consideration of the compatibility with the roll-stamping process. LGP fabricating tests were performed using a roll-stamping process with four different roll pressures. Pattern shapes on the stamper fabricated by laser ablation and transcription ratios of the roll-stamping process were analyzed, and LGP luminance was evaluated. Based on the evaluation, optical simulation model for LGP was made and simulation accuracy was evaluated. Simulation results showed good agreements with optical performance of LGPs in the brightness and uniformity. It was also shown that the roll-stamped LGP has the possibility of better optical performance than the conventional injection molded LGP. It was also shown that the roll-stamped LGP with the laser ablated stamper is potential to have better optical performance than the conventional injection molded LGP.

Recent observations in the straits of the East/Japan Sea: A review of hydrography, currents and volume transports

Na, H.,Isoda, Y.,Kim, K.,Kim, Y.H.,Lyu, S.J. Elsevier 2009 Journal of marine systems Vol.78 No.2

Recent observations of hydrography, currents and volume transports in the straits of the East/Japan Sea are reviewed. It is newly found that bottom cold water in the Korea/Tsushima Strait originating from the northern region of the East/Japan Sea appears not only in summer and autumn but also in winter. Intensive observations in the Korea/Tsushima Strait revealed two distinct cores of northeastward currents in the upper layer of the western and eastern channels. Mean volume transport through the Korea/Tsushima Strait is calculated as 2.5+/-0.5 Sv from four-year direct and indirect measurements. As continuous monitoring has started in the Tsugaru and Soya Straits, understanding of temporal variability of currents and volume transports through the straits is in progress. For the first time, simultaneous time series of volume transports are available in the Korea/Tsushima and Tsugaru Straits during the winter of 1999-2000. Ouflow through the Tsugaru Strait accounts for about 70% of inflow through the Korea/Tsushima Strait for this period.

Characteristics of Ni-W bimetallic nanoparticle via reactive RF thermal plasma synthesis

Na, H.,Lee, W.,Choi, H. MPR Pub. Services 2015 INTERNATIONAL JOURNAL OF REFRACTORY METALS AND HAR Vol.53 No.1

Nickel-tungsten binary nanoparticle was synthesized by the inductively coupled radio-frequency thermal plasma process which belongs to vapor phase condensation technology. Nanoparticles are nucleated from supersaturated vapor species. Accordingly, vaporization of feedstock micro-powder is the pre-requisite step for nanoparticle synthesis. In this context, nickel hydroxide and tungsten trioxide micro-powders were chosen for precursor feedstock of each Ni and W because of their low boiling points. It was confirmed that each feedstock was fully vaporized and mostly reduced by argon-hydrogen thermal plasma as the results of pure nanoparticle synthesis from each feedstock. Blended feedstock was prepared by turbulent mixing and the weight fraction of nickel hydroxide in the blended powder was 0.5. Weight fraction of tungsten in the synthesized binary nanoparticle was 0.588 and it was well consistent to theoretical one of blended feedstock (0.556). However, chemical composition at the particle level showed a substantial distribution. Full vaporization of each feedstock resulted in coincidence of overall chemical composition, however, particle level chemical composition distribution was due to inhomogeneous condensation of Ni-W vapor mixture. X-ray diffraction and convergent beam electron diffraction revealed that Ni-W binary nanoparticles were composed of γ-Ni and amorphous phase. Rapid cooling driven co-condensation as well as supersaturating of alloying element and oxygen caused non-equilibrium phase evolution.

Electrical responses of short-channel organic transistor prepared by solution-processed organic crystal wire mask

Na, H.,Cho, H.,Sim, K.,Shim, H.,Kim, S.J.,Pyo, S. Elsevier Science 2014 Organic Electronics Vol.15 No.11

We report a formation of a solution-grown single crystal wire mask for the fabrication of short-channel organic field-effect transistor with enhanced dynamic response time. The various channel length, ranging from submicrometer to a few micrometers, were obtained by controlling the concentration of solution and processing conditions. We fabricated p- and n-channel bottom-contact organic field-effect transistors using pentacene and PTCDI-C<SUB>13</SUB>, respectively, and static and dynamic electrical characteristics of the devices were investigated. The highest and average field-effect hole mobility values were found to be 0.892cm<SUP>2</SUP>/Vs and 0.192cm<SUP>2</SUP>/Vs, respectively. The load type inverter based on the short-channel transistor connected with a 2MΩ resistor showed a clear switching response when square wave input signals up to 1kHz were applied at V<SUB>DD</SUB>=-60V.

SH-SY5Y 신경아 종야 세포의 분화 과정에서 : 세포 증식의 조절에 관한 연구

권혁만,신나영 단국대학교 1998 論文集 Vol.32 No.-

Staurosporine or retinoic acid (RA)/brain-derived neurotrophic factor (BDNF) induce the differentiation of SH-SY5Y cell, a human neural crest-derived tumor, in aspects of neurite outgrowth and the synthesis of neuron markers such as growth-associated protein 43 and neuropeptide Y. In this study, we found that SH-SY5Y cells responded differently to these treatments in cell proliferation. With RA and BDNF, the cell cycle progress of SH-SY5Y cells was arrested with a concomitant induction of C아 inhibitors such as p21 and p27. On the other hand, the staurosporine-induced differentiation did not suppress the proliferation of SH-SY5Y cells, and the level of p21 and p27 proteins did not change. These result suggest that the differentiation and the cell cycle arrest of SH-SY5Y cells may occur independently and the accumulation of p21 and p27 proteins is likely to be correlated with the cell cycle arrest.