• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.2
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• pp.282-289
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• 2008

To improve the efficiency of PDP TV, it should minimize the power losses transpired during AC-to-DC power conversion and PDP driving process. Generally the input power supply for PDP driving employes a two-stage power factor corrected converter, and it needs additional DC-to-DC converters to supply driving power for reset circuit ed sustain driver, which has high power consumption. However, such a circuit configuration has a difficulty for the PDP market requires low cost. To alleviate this problem, a new circuit composition is presented. It integrates input power supply with reset and sustain driver in a single power stack The input power supply of the proposed circuit has a single-stage structure to minimize power conversion loss, and it directly supplies power to the sustain driver so as to reduce the system size and cost.

• Korean Journal of Social Welfare Studies
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• no.36
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• pp.129-149
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• 2008

This study examined gender differences of gender-role stereotype among Korean youth. Specifically, the contribution of youth's individual traits and parental background factors were tested. Data came from Korea Youth Panel Survey 2005. Analysis methods were t-test and regression analysis. The major findings of this study are as follows. First, the boys exhibited higher scorers on gender-role stereotype than the girls. Second, both boys and girls acquired higher masculine gender-role stereotype than feminine. Third, self-esteem, age, and mother's education influenced significantly boys' masculine and feminine gender-role stereotype. And self-esteem, age, mother's education, father's education and family structure influenced significantly girls' masculine and feminine gender-role stereotype, but mother's work status and income level did not. The limitations and implications of the findings from this study were discussed with respect to further studies.

• Journal of Korea Port Economic Association
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• v.34 no.3
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• pp.75-92
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• 2018

The purpose of this study is to analyze whether innovation activities of logistics firms affect innovation performance and service quality improvement and whether innovation performance and service quality as a result of innovation activities affect these firm's business performance. First, I undertake a review of previous studies and theories related to innovation activity and innovation performance. Additionally, previous studies on improvement of service quality along through innovation performance were analyzed. Based on this, I set up a research structure and hypotheses. To this end, I used the workplace panel survey data of the Korea Labor Institute(KLI) and used a total of 88 samples. I use the Partial Least Square(PLS) approach to structural equation modeling. The results of the empirical analysis show that innovation activities of logistics firms have a positive effect on innovation performance and service quality improvement, and innovation performance and service quality have a positive effect on financial performance. Evidently, innovation activities bring a clear competitive advantage to the logistics firms and improve their service quality. This implies the ability of logistics firms to survive amidst competition while getting a competitive edge.

• The Journal of the Korea Contents Association
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• v.19 no.2
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• pp.248-258
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• 2019

The importance of the creative class has been emphasized as the industrial structure changes. However, there are only a few studies on gender wage difference in the creative class. The purpose of this study is to analyze the various factors influencing the gender wage gap in the creative class by using labor panel data. The results of this study are as follows: First, it was found that the wage of the male creative class is higher than the wage of the female creative class. Second, there were different factors affecting wages depending on the gender of the creative class. Third, female workers in the creative class suffer wage discrimination due to differences, but a larger part is due to gender discrimination. Fourth, compared to the non-creative classes, the gender wage gap of the creative classes was small. The gender gap caused by discrimination was the highest among the younger generation.

• Advances in materials Research
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• v.8 no.2
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• pp.117-135
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• 2019

The lifetime of a gas turbine combustor is typically limited by the durability of its liner, the structure that encloses the high-temperature combustion products. The primary objective of the combustor thermal design process is to ensure that the liner temperatures do not exceed a maximum value set by material limits. Liner temperatures exceeding these limits hasten the onset of cracking which increase the frequency of unscheduled engine removals and cause the maintenance and repair costs of the engine to increase. Hot gas temperature prediction can be considered a preliminary step for combustor liner temperature prediction which can make a suitable view of combustion chamber conditions. In this study, the temperature distribution of ceramic panels for a V94.2 gas turbine combustor subjected to realistic operation conditions is presented using three-dimensional finite difference method. A simplified model of alumina ceramic is used to obtain the temperature distribution. The external thermal loads consist of convection and radiation heat transfers are considered that these loads are applied to flat segmented panel on hot side and forced convection cooling on the other side. First the temperatures of hot and cold sides of ceramic are calculated. Then, the thermal boundary conditions of all other ceramic sides are estimated by the field observations. Finally, the temperature distributions of ceramic panels for a V94.2 gas turbine combustor are computed by MATLAB software. The results show that the gas emissivity for diffusion mode is more than premix therefore the radiation heat flux and temperature will be more. The results of this work are validated by ANSYS and ABAQUS softwares. It is showed that there is a good agreement between all results.

• Journal of the Korea Society of Computer and Information
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• v.26 no.1
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• pp.253-258
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• 2021

In this study, we explored consumers' the privacy attitudes and Internet activities on the expectations of the fourth industrial revolution. Furthermore, we examined the moderating effect of Internet activities between the privacy attitudes and the expectations of the fourth industrial revolution. Research data are 2018 Korea media panel survey provided by Korea Information Society Development Institute. As a result, concerns about privacy were negative on the expectations of the fourth industrial revolution. Consumer's internet activities had a positive effect on the expectations of the fourth industrial revolution. Concerns about privacy have a negative effect on the expectations of the fourth industrial revolution, but active internet activities have mitigated it or turned it into a positive. This study will contribute as basic data for more active responses in the economic structure facing the 4th industrial revolution.

• The Journal of the Korea Contents Association
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• v.21 no.8
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• pp.478-488
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• 2021

This study analyzes the change in the contribution of the elderly to income inequality by using the Gini coefficient and the decile distribution ratio from the data of the Korea Welfare Panel Survey from 2007 to 2018 on economic inequality in old age. According to the study, the Gini coefficient of total income gradually decreased from 0.430 in 2007 to 0.383 in 2018. As a result, inequality decreased. Also, the higher the income quintile, the higher the income growth rate. Market income inequality has increased and inequality between public and private transfer income has decreased. Analysis of the contribution of income inequality to total income confirmed that public transfer income has replaced the role of private transfer income in reducing inequality over time. The expansion of public transfer income for the maintenance of basic living of the elderly is an important source of income for the elderly despite the crowding-out effect of private transfer income, market income, public and private transfer income, which are components of the income structure of the elderly, mutually complement total income. Therefore, it is important to identify income sources that contribute to alleviating income inequality among the elderly and reflect them in policy-making process.

• Earthquakes and Structures
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• v.22 no.6
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• pp.539-548
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• 2022

Steel plate shear walls (SPSWs) are one of the most important and widely used lateral load-bearing systems. The reason for this is easier execution than reinforced concrete (RC) shear walls, faster construction time, and lower final weight of the structure. However, the main drawback of SPSWs is premature buckling in low drift ratios, which affects the energy absorption capacity and global performance of the system. To address this problem, two groups of SPSWs under cyclic loading were investigated using the finite element method (FEM). In the first group, several series of circular rings have been used and in the second group, a new type of SPSW with concentric circular rings (CCRs) has been introduced. Numerous parameters include in yield stress of steel plate wall materials, steel panel thickness, and ring width were considered in nonlinear static analysis. At first, a three-dimensional (3D) numerical model was validated using three sets of laboratory SPSWs and the difference in results between numerical models and experimental specimens was less than 5% in all cases. The results of numerical models revealed that the full SPSW undergoes shear buckling at a drift ratio of 0.2% and its hysteresis behavior has a pinching in the middle part of load-drift ratio curve. Whereas, in the two categories of proposed SPSWs, the hysteresis behavior is complete and stable, and in most cases no capacity degradation of up to 6% drift ratio has been observed. Also, in most numerical models, the tangential stiffness remains almost constant in each cycle. Finally, for the innovative SPSW, a relationship was suggested to determine the shear capacity of the proposed steel wall relative to the wall slenderness coefficient.

• Journal of Korea Trade
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• v.24 no.7
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• pp.54-72
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• 2020

Purpose - This study explores the contextual factors that affect the relationship between CEO overseas experience and firm internationalization. This study incorporates a wide range of contextual factors, including mega, macro, and micro variables. In particular, this study goes a step further from prior studies by incorporating a higher-order variable i.e., the global financial crisis that can constrain the managerial discretion of a CEO. Design/methodology - To structure the balanced data set before and after the 2008 global financial crisis, we used the data for the years from 2002 to 2014 from a sample of Korean manufacturing firms. Ultimately, 1101 firm-year unbalanced panel observations from 101 firms were used for the analysis. Findings - Our main findings can be summarized as follows. CEO overseas experience is positively related to firm internationalization. However, this relationship varies depending on the CEOs level of managerial discretion. As for the constraining moderation, the global financial crisis weakened the positive relationship between CEO overseas experience and firm internationalization. As for the enabling moderation, the CEOs tenure strengthened the relationship. Originality/value - This study adopted the knowledge, skills, and abilities (KSA) framework to explain the relationship between CEO overseas experience and firm internationalization. Moreover, we argue that the CEO-internationalization relationship depends on the specific context of the managerial discretion, focusing on the 2008 global financial crisis. Empirically, this study adopted the 2SLS procedure to correct endogeneity. Instead of taking the actual value of prior internationalization as a control, we estimated prior internationalization using the instrument variables at an industry level. This procedure made our estimation more robust.

• Coupled systems mechanics
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• v.11 no.6
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• pp.557-586
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• 2022

In spite of extensive testing of the individual shear wall and the coupling beam (CB), numerical and experimental researches on the seismic behavior of CSW are insufficient. As far as we know, no previous research has investigated the affectations of position of CB regarding to the slab level (SL). So, the investigation aims to enhance an overarching framework to examine the consequence of connection positions between CB and SL. And, three cases have been created. One is composed of the floor slab (FS) at the top of the CB (FSTCB); the second is created with the FS within the panel depth (FSWCB), and the third is employed with the FS at the bottom of the CB (FSLCB). And, FEA is used to demonstrate the consequences of various CB positions with regard to the SL. Furthermore, the main measurements of structure response that have been investigated are deformation, shear, and moment in a coupled beam. Additionally, wall elements are used to simulate CB. In addition, ABAQUS software was used to figure out the strain distribution, shear stress for four stories to further understand the implications of slab position cases on the coupled beam rigidity. Overall, the findings show that the position of the rigid linkage among the CB and the FS can affect the behavior of the structures under seismic loads. For all structural heights (4, 8, 12 stories), the straining actions in FSWCB and FSLCB were less than those in FSTCB. And, the increases in displacement time history response for FSWCB are around 16.1-81.8%, 31.4-34.7%, and 17.5% of FSTCB.