• Journal of Labour Economics
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• v.31 no.2
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• pp.35-72
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• 2008

This paper examines whether me effects of product demand shocks on employment are different between unionized and non-unionized firms, using new firm-level longitudinal data in Korea over the period 1997~2004. The estimation result shows that the effects of both negative and positive demand shocks on employment are smaller in unionized firms than in non-unionized firms. The result implies that unions appear to provide their members with job stability in response to negative demand shocks, while playing a very limited role in employment determination in response to positive demand shocks leading to employment expansion.

• Journal of Power Electronics
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• v.18 no.4
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• pp.1245-1254
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• 2018

The stability of a grid-connected system (GCS) has become a critical issue with the increasing utilization of renewable energy sources. Under grid faults, however, a grid-connected inverter cannot work efficiently by using only the traditional droop control. In addition, the unbalance factor of voltage/current at the common coupling point (PCC) may increase significantly. To ensure the stable operation of a GCS under grid faults, the capability to compensate for grid imbalance should be integrated. To solve the aforementioned problem, an improved voltage-type grid-connected control strategy is proposed in this study. A negative sequence conductance compensation loop based on a positive sequence power droop control is added to maintain PCC voltage balance and reduce grid current imbalance, thereby meeting PCC power quality requirements. Moreover, a stable analysis is presented based on the small signal model. Simulation and experimental results verify the aforementioned expectations, and consequently, the effectiveness of the proposed control scheme.

• The Journal of the Korea Contents Association
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• v.17 no.7
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• pp.592-599
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• 2017

The possibility of establishing the committee was increased because of the pledge of the President Moon Jaein for the national education committee. Thus, the purpose of this study was to discuss about its necessity and the meaning of legislation. The study method was to analyze existing studies (concept establishment, overseas cases, and legal research), media materials, and internet materials. It also suggested positive and negative functions in establishing the national education committee. Its positive functions are; first, stability of policy, second, political neutrality, third, seeking the nature of education, and fourth, improvement of possibility. Negative functions are; first, establishing the committee could be poison, second, argument in position and role, third, issue of agreement, and fourth, populism policy oriented.

• 한국연소학회:학술대회논문집
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• 2007.05a
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• pp.139-144
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• 2007

A micro cyclone combustor was developed to be used as a component of mobile power generator (MPG). The cyclone combustor was designed so that fuel and air were supplied to the combustion chamber separately to prevent a flash-back. The flame shape stabilized inside the micro cyclone combustor was visualized experimentally and the flow field and the combustion characteristics of the combustor were investigated numerically. The global equivalence ratio (${\Phi}$), defined using the fuel and air flow rates, was introduced to examine the overall flow and flame features of the combustor. The flame stabilization mechanism could be well understood using the velocity distribution inside the combustor. For only non-reacting case, it was found that a weak recirculating zone was formed upper the fuel-supplying tube in case of ${\Phi}$ < 1.0. It was also found that small regions that have a negative axial velocity exist near the fuel injection ports for both of non-reacting and reacting case. It was identify that a flame front was stabilized at the negative axial velocity regions near the fuel injection ports.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.49-56
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• 2005

The negative skin friction on piles, which are installed in currently consolidating soft deposits, creates significant problems on the stability of pile foundations. This study investigated whether or not the pile foundation designs were appropriate in soft deposits with large amount of consolidation settlement. The final settlements of the grounds along the pile depth were estimated by the soil parameters obtained from the laboratory tests and by the field-measured settlement curves, if they were available. The displacement of the piles along the pile depth was estimated by both the load transfer method and the numerical method. Both methods gave similar locations of neutral points and magnitudes of the maximum axial forces. The movements of the ground and the piles were compared to calculate the down drag acting on piles. For the piles whose bearing capacities were less than the design loads including the down drag, slip layer coatings and/or incrementing of the penetration depth into the bearing stratum were proposed to improve the piles capacities.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.628-633
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• 1996

Large saturation magnetization $4pM_s$ is essentially required for soft magnetic thin layers used in magnetic recording devices. Amorphous Co-based alloys and Fe-Co alloys may be regarded as one of the candidates for soft magnetic materials which possess large $4\piM_s$. Some preparation process to improve soft magnetism of these films were performed in this study. Addition of Ta seemed to be effective to change the magnetostriction constant $\lambda$ from positive value to negative one. The magnetoelastic energy $K_e$ is strongly dependent on $\lambda$. $(Co_{95.7}Zr_{4.3})_{100-x}Ta_x$ films with $K_e$ of negative value have sufficiently soft magnetic characteristics. $Fe_{90}Co_{10}$ alloy exhibits extremely large $4\piM_s$, of about 24 kG. Addition of N and Ta to $Fe_{90}Co_{10}$ films improved the soft magnetism of them. The $Fe_{82.0}Co_{7.6}Ta_{10.4}$:N/Ti multilayered films exhibit better soft magnetic properties and better thermal stability than Fe-Co-Ta:N singlelayer films.

• Journal of the Korean Operations Research and Management Science Society
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• v.41 no.1
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• pp.1-19
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• 2016

While previous studies on service failures mainly focused on general services, this study examines the effects of failed financial services on the psychological process and behavioral responses of consumers. The important factors of financial service (relational benefits, convenience, branch satisfaction, product diversity, company stability, and product profitability) are regarded as antecedents in our model. We study how each factor of failed financial service affects the negative emotions of consumers through the attribution process and how these arising emotions influence their behavioral responses. Through path analysis, this study shows that failure of service factors of relational benefits, branch satisfaction, and convenience induces disappointment, with the mediation effect of external attribution. Meanwhile, failure of service factors of product diversity and product profitability induces regret, with the mediation effect of internal attribution. Disappointment leads to complaint behavior, and regret leads to switching behavior. Unlike previous studies, the present one considers the important factors of financial service and their effects on the affective and behavioral responses of consumers.

• Journal of Power Electronics
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• v.13 no.3
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• pp.469-478
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• 2013

This paper proposes a novel scheme for the current controller for the grid-side converter (GSC) of permanent-magnet synchronous generator (PMSG) wind turbines to eliminate the high-order harmonics in the grid currents under grid voltage disturbances. The voltage unbalance and harmonics in three-phase systems cause grid current distortions. In order to mitigate the input current distortions, multi-loop current controllers are applied, where the positive-sequence component is regulated by proportional-integral (PI) controllers, and the negative-sequence and high-order harmonic components are regulated by proportional-resonance (PR) controllers. For extracting the positive/negative-sequence and harmonic components of the grid voltages and currents without a phase delay or magnitude reduction, composite observers are applied, which give faster and more precise estimation results. In addition, an active damping method using PR controllers to damp the grid current component of the resonant frequency is employed to improve the operating stability of VSCs with inductor-capacitor-inductor (LCL) filters. The validity of the proposed method is verified by simulation and experimental results.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.885-896
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• 2021

The general role of commercial banks is to provide financial services to the general public and business, ensuring economic and social stability and sustainable growth of the economy. Commercial banks play an important role in mobilizing and channelizing funds for investment activities. This study analyzes the impact of the key financial variables on the net profit of the selected commercial banks in Oman. The study employs times series panel data - cross-sectional analysis of the key financials of five leading commercial banks for a period of 13 years from 2007 to 2019. The results reveal that the correlation matrix of the selected variables has a positive relationship with net profit, assets, deposits, loans, and interest income. However, the findings also shows a negative relationship between net profit and net loans to total deposits ratio. The study found net loans is the main independent variable that influences the profitability of the banks since the key source of revenue comes from the lending operations. The assets, total capital adequacy ratio have a mixed effect on the profitability of commercial banks. The total deposits and capital adequacy ratio have a negative effect on profitability mainly because excessive liquidity will increase the cost of capital and reduce the return on investment. Focusing on lending operations with a sound credit portfolio will improve profitability.

• Molecules and Cells
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• v.44 no.7
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• pp.444-457
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• 2021

Although the mechanism of chronic myeloid leukemia (CML) initiation through BCR/ABL oncogene has been well characterized, CML cell differentiation into erythroid lineage cells remains poorly understood. Using CRISPR-Cas9 screening, we identify Chromobox 8 (CBX8) as a negative regulator of K562 cell differentiation into erythrocytes. CBX8 is degraded via proteasomal pathway during K562 cell differentiation, which activates the expression of erythroid differentiation-related genes that are repressed by CBX8 in the complex of PRC1. During the differentiation process, the serine/threonine-protein kinase PIM1 phosphorylates serine 196 on CBX8, which contributes to CBX8 reduction. When CD235A expression levels are analyzed, the result reveals that the knockdown of PIM1 inhibits K562 cell differentiation. We also identify TRIM28 as another interaction partner of CBX8 by proteomic analysis. Intriguingly, TRIM28 maintains protein stability of CBX8 and TRIM28 loss significantly induces proteasomal degradation of CBX8, resulting in an acceleration of erythroid differentiation. Here, we demonstrate the involvement of the CBX8-TRIM28 axis during CML cell differentiation, suggesting that CBX8 and TRIM28 are promising novel targets for CML research.