• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.159-162
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• 2000

Novel simulated floating inductor (SFI) using fully-differential operational transconductance amplifier (FOTA) is presented. The SFI only consists of two FOTA and a capacitor. A ladder-type third-order elliptic low-pass filter is also presented for the SFI’s application. The theory of operations described and the simulation results are used to verify theoretical predictions. The SFI shows close agreement between predicted behavior and simulation performance. The simulation results that the SFI have The temperature coefficient of-179 ppm/$^{\circ}C$ and Q factor of 120 at 200kHz at supply voltage ${\pm}$5 V.

• Korean Journal of Optics and Photonics
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• v.10 no.4
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• pp.294-300
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• 1999

The density matrix is solved more rigorously, compared with the third-order pertubation method used in the conventional theory, for a semiconductor laser amplifier. Then the coupled wave equations are derived to explain the wavelength conversion due to the spectral hole burning in the semiconductor optical amplifier. It is shown that our results can explain the effect of saturation of the population density on the electric polarization, which affects the four-wave mixing and wavelength conversion, better than the conventional theroy where the third-order pertubation is used.

• Advances in nano research
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• v.8 no.3
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• pp.203-214
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• 2020

This paper investigated bending of magneto-electro-elastic (MEE) nanobeams under hygro-thermal loading embedded in Winkler-Pasternak foundation based on nonlocal elasticity theory. The governing equations of nonlocal nanobeams in the framework parabolic third order beam theory are obtained using Hamilton's principle and solved implementing an analytical solution. A parametric study is presented to examine the effect of the nonlocal parameter, hygro-thermal-loadings, magneto-electro-mechanical loadings and aspect ratio on the deflection characteristics of nanobeams. It is found that boundary conditions, nonlocal parameter and beam geometrical parameters have significant effects on dimensionless deflection of nanoscale beams.

• Journal of Families and Better Life
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• v.17 no.4
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• pp.47-60
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• 1999

The predictions derived from Sternberg's triangular theory of love were tested in order to explain the love relationships in marriage among Korean people. We were first interested in whether the subjective love experiences of respondents could be characterized by three components: intimacy passion and commitment we then attempted to examine the time course of each component as the marital relationships continued. 16897 married men and women were asked to complete the questionnaire including the love scale developed by researchers based on Sernberg's and other researchers' work. The results are as follows: First the love experienced by Korean men and women in their marriage can be classified by 3 dimensions: intimacy passion and commitment. Secon intimacy is the most powerful indicator of love in marital rlationships follows bgy passion and commitment. Third each of the 3 dimensions of marital love showed a U-shaped pattern as the marriage continued. Fourth commitment was more table than the other 2 dimensions throughout the marriage. The resultso f the study showed that Sternberg's triangular theory of love is useful to explain the marital love among Korean people.

• Journal of the Korean Society of Clothing and Textiles
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• v.41 no.3
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• pp.556-574
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• 2017

This study explored the appearance management experiences of breast cancer patients undergoing mastectomy. For data collection, one-on-one interviews were held with 18 Korean females diagnosed with breast cancer from the first stage to the third stage from 2008 to 2015. The data was analyzed through a three-step analysis of grounded theory. QSR NVivo 11.0 for Mac was applied in order to avoid biased results according to the subjective viewpoint of researchers. From open coding results, six paradigms and 15 categories were drawn. The results of axial coding showed that the psychological changes category was the central phenomenon. Additionally, three categories (skin changes, scalp/hair changes, and general reactions) were found to be causal conditions, and five paradigms (clothing behavior, skin care behavior, makeup behavior, scalp/hair-care behavior, and shopping behavior) were found to be action/interaction strategies. Last, selective coding integrated fragmented qualitative data through open coding and axial coding in order to derive explanatory narratives. A comprehensive examination of the appearance management behaviors of breast cancer patients suffering from extreme stress due to physical/psychological changes enables this study to provide a foundation for related studies to be activated in the clothing and textiles discipline.

• Structural Engineering and Mechanics
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• v.59 no.1
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• pp.153-186
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• 2016

This paper addresses temperature-dependent nonlinear vibration and instability of embedded functionally graded (FG) pipes conveying viscous fluid-nanoparticle mixture. The surrounding elastic medium is modeled by temperature-dependent orthotropic Pasternak medium. Reddy third-order shear deformation theory (RSDT) of cylindrical shells are developed using the strain-displacement relations of Donnell theory. The well known Navier-Stokes equation is used for obtaining the applied force of fluid to pipe. Based on energy method and Hamilton's principal, the governing equations are derived. Generalized differential quadrature method (GDQM) is applied for obtaining the frequency and critical fluid velocity of system. The effects of different parameters such as mode numbers, nonlinearity, fluid velocity, volume percent of nanoparticle in fluid, gradient index, elastic medium, boundary condition and temperature gradient are discussed. Numerical results indicate that with increasing the stiffness of elastic medium and decreasing volume percent of nanoparticle in fluid, the frequency and critical fluid velocity increase. The presented results indicate that the material in-homogeneity has a significant influence on the vibration and instability behaviors of the FG pipes and should therefore be considered in its optimum design. In addition, fluid velocity leads to divergence and flutter instabilities.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.63-64
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• 2020

The purpose of this study is to find out how construction sites workers experience adaptation processes in relation to the prevention of safety accidents in the workplace through the method of grounded theory. In order to understand the experience of preventing safety accidents of workers at construction sites, a grounded theory analysis method was chosen. In order to achieve the purpose of this study, the first questionnaire was sent to 17 people working in the construction site by e-mail, and the participants of the study were met one by one for in-depth interviews. As a result of this study, the paradigm model of the experience of preventing safety accidents of workers at construction sites was classified into causal conditions, contextual conditions, central phenomena, intervening conditions, action/interactions, and outcomes. The conclusions of this study are as follows. First, forming a safety culture that can improve the safety awareness of construction sites is a priority. Second, it is necessary to improve self-management capabilities so that construction workers can accurately diagnose their current state such as their own body, emotion, and cognition and provide appropriate safety education. Third, providing safety education for construction workers with negative thoughts or distorted beliefs about safety accidents needs to include psychological treatment and counseling, such as methods of emotional purification, methods of relieving and managing stress, and methods of removing trauma.

• International Area Studies Review
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• v.16 no.1
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• pp.123-146
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• 2012

In this paper, we did on the new theory, policy, institution and legal research on the international competition order and justice society for 21st century. At first, we introduced the basic of competition law for fairness of trade in the new international market order under WTO. Secondly, we are researched on the economic approach of the competition law, market competition order and justice society in the new globalism. Third, we studied the international circumstance through the analysis of the patterns of the anti-competition practices and the regulation systems for competition order. We also reviewed the execution criteria and precedents of the fairness theory and competition laws in the USA, EU, Japan, and Korea, briefly. Finally, we presented to the alternative policies that based on our study about the new theory, policy, institution, competition law in opinion from reach the international market competition, fairness society and economic justice for 21st century under WTO.

• Journal of Distribution Science
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• v.13 no.10
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• pp.73-82
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• 2015

Purpose - This paper aims to investigate whether information asymmetry could explain capital structures in Korean corporations. According to Myers (1984), firms prefer internal funding to external financing due to the costs associated with information asymmetry. When external financing is necessary, firms prefer to issue debt rather than equity by the same reasoning. Since Shyam-Sunder and Myers (1999), numerous studies continue to debate the validity of the theory. In this paper, we show how the theory depends on assumptions and incorporated variables. We hope our investigation can provide helpful implications regarding capital structure, information asymmetry, and other firm characteristics. Specifically, our empirical results are complementary to the analysis of Son and Lee's (2015), a recent study that examines the pecking order theory prediction for Korean retail firms. Research design, data, and methodology - We test empirical models that are some variants of model used in Shyam-Sunder and Myers (1999). The financial and accounting data are provided by WISEfn for the firms listed on the KOSPI during 1990 to 2013. Bond ratings are supplied by the Korea Investor Service (KIS). We take into account the heterogeneity in debt capacity; a firm's debt capacity is measured by using the method of Lemmon and Zender (2010) based on its bond ratings. Finally, we estimate empirical models suggested by Shyam-Sunder and Myers (1999), Frank and Goyal (2003), and Lemmon and Zender (2010). Results - First, we find that Shyam-Sunder and Myers' (1999) prediction fails to explain total debt changes of Korean firms. Second, we find a non-monotonic relationship between total debt changes and financial deficits with respect to debt capacity. This contradicts the prediction of Lemmon and Zender (2010) that argues the pecking order theory survives with a monotonically increasing relationship. Third, we estimate a negative correlation coefficient between financial deficit and current debt changes. The result is the complete opposite of the prediction of Lemmon and Zender (2010). Finally, we also confirm the non-monotonic relationship between non-current debt changes and financial deficits with respect to debt capacity. Yet, the slope of coefficient is smaller than that of total debt change case. Indeed, the results are, to some extent, consistent with the prediction of pecking order theory, if we exclude the mid-debt capacity firms. Conclusions - Our empirical results complementary to the analysis of Son and Lee (2015), a recent study focusing on capital structure in Korean retail firms; their paper suggests interesting topics regarding capital structure, information asymmetry, and other firm characteristics in Korean corporations. Contrary to Son and Lee (2015), our results show that total debt changes and current debt changes are inconsistent with the prediction of Shyam-Sunder and Myers (1999). However, similar to Son and Lee (2015), non-current debt changes are consistent with the pecking order prediction, in the case of excluding the mid-level debt capacity firms. This contrast allows us to infer that industry characteristics significantly affect the validity of the pecking order prediction. Further studies are needed to analyze the economics behind this phenomenon, which is beyond the scope of our paper. In addition, the estimation bias potentially matters regarding the firm-level debt capacity calculation. We also reserve this topic for future research.

• Steel and Composite Structures
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• v.22 no.6
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• pp.1239-1259
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• 2016

The modified couple stress-based third-order shear deformation theory is presented for sigmoid functionally graded materials (S-FGM) plates. The advantage of the modified couple stress theory is the involvement of only one material length scale parameter which causes to create symmetric couple stress tensor and to use it more easily. Analytical solution for dynamic instability analysis of S-FGM plates on elastic medium is investigated. The present models contain two-constituent material variation through the plate thickness. The equations of motion are derived from Hamilton's energy principle. The governing equations are then written in the form of Mathieu-Hill equations and then Bolotin's method is employed to determine the instability regions. The boundaries of the instability regions are represented in the dynamic load and excitation frequency plane. It is assumed that the elastic medium is modeled as Pasternak elastic medium. The effects of static and dynamic load, power law index, material length scale parameter, side-to-thickness ratio, and elastic medium parameter have been discussed. The width of the instability region for an S-FGM plate decreases with the decrease of material length scale parameter. The study is relevant to the dynamic simulation of micro structures embedded in elastic medium subjected to intense compression and tension.