• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.2
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• pp.257-266
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• 1999

In this paper, a spline-type divided-difference interpolation technique is proposed to efficiently evaluate the impedance matrix elements in the MoM analysis of layered medium problems. This method is combined with the fast computational method of the basis-expanded and tested dyadic Green's functions (expressed in the spectral domain integrals) in a recent literature. For the sake of its validity, the proposed method is applied to analyze the characteristics of a microstrip gap discontinuity, a microstrip filter, and an aperture coupled patch antenna. Numerical results obtained by this approach are in good agreement with those of other approaches.

• Korean Journal of Child Studies
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• v.27 no.4
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• pp.165-184
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• 2006

This ethnography explored the construction of a social network and its function in a classroom of toddlers in a day-care center located in Vermont. The classroom activities of 9 two-year-old toddlers were observed for about two months, compiled and categorized. Then, the themes of psychological functions were reconstructed in data analysis. Results showed that toddlers constructed multiple relations with all peers beyond the dyadic. They also transmitted information to teachers as well as peers in indirect ways. These direct-multiple interactions as well as indirect interactions reflect the social network of Lewis' (2005) theory. In the construction of social networks, the toddlers developed communication skills, turn-taking skills, leadership, and imitation.

• Speech Sciences
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• v.5 no.1
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• pp.23-33
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• 1999

Mallat has shown that, with a proper choice of wavelet function, the local maxima of wavelet transformed signal indicate a sharp variation in the signal. Since the glottal closure causes sharp discontinuities in the speech signal, dyadic wavelet transform can be useful for detecting abrupt change in the voiced sounds, i.e., epochs. In this paper, we investigate the glottal closure instants obtained from the wavelet analysis of speech signal and compare them with those obtained from the EGG signal. Then, we detect pitch period of speech signal on the basis of these results. Experimental results demonstrated that local maxima of wavelet transformed signal give accurate estimation of epoch and pitch periods of voiced sound obtained by the proposed algorithm also correspond to those from EGG well.

• 한국벤처창업학회:학술대회논문집
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• 2022.04a
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• pp.157-161
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• 2022

Building on the DC interaction model between a parent company and its spin-offs, we examine that a dyadic relationship can be differentiated within the functions of space, motivation, and time. We investigate that these three factors encompassing the parent-spin-off DC relationship can be applicable to both linear(i.e., geographic proximity and low spin-off CEO's salary is positive) and nonlinear(i.e., too much frequency of new spin-off creation is as harmful as too little) effects on determining the performance of spin-off firms. The direction of causality is underpinned by social capital, human capital, and compensation-activation theory rather than by the normal consequences of previous empirical research. Further, our results suggest the overlap between DC and entrepreneurship; namely, spin-off firms create, learn, and exploit opportunities through a reconfiguration of parent DC so that DC establishes itself as a key concept in the entrepreneurship domain.

• Information Systems Review
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• v.19 no.1
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• pp.147-168
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• 2017

We investigated perceptual similarity and the difference between client and vendor in information technology (IT) outsourcing projects. Specifically, we focused on each player's perception of how the fit of governance and peripheral knowledge affects the performance of IT project outsourcing. For 107 IT projects, we surveyed both client and vendor in the same IT projects and compared the responses of each side. Through a dyadic analysis, we first found that both client and vendor put more weight on the vendor's peripheral knowledge than that of the client as a positive influencer of project performance. However, regarding the governance style of an IT project, client and vendor showed completely different perspectives. The client believed that the vendor's peripheral knowledge positively contributes to the performance of IT project under the governance of outcome control. However, the vendor showed that its peripheral knowledge creates synergy effects under the governance of process control. Our interpretation of the perceptual similarity and difference between client and vendor delivers managerial implications for businesses that process IT projects.

• Child Health Nursing Research
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• v.24 no.4
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• pp.383-392
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• 2018

Purpose: The purpose of this study was to identify factors associated with smartphone overdependency in preschool children based on an analysis of mother, child, and their mutual dyadic relationships. Methods: Data were collected from 171 mothers of preschool children enrolled at daycare centers and kindergartens from January to March 2018. The data were analyzed by descriptive statistics, the t-test, analysis of variance with $Scheff{\acute{e}}$ post hoc test, Pearson correlation coefficient, and hierarchical regression analysis using SPSS version 24. Results: The self regulation of preschool children (${\beta}=-.358$, p<.001) was the factor most closely associated with smartphone overdependency. The second most closely associated factor was children's use of a smartphone 0.5-1 hour daily (${\beta}=-.249$, p=.005). Additional associated factors were mothers' use of a smartphone for 3-4 hours daily (${\beta}=.217$, p=.002), children's use of a smartphone for less than 0.5 hour daily (${\beta}=-.212$, p=.006), and children's use of a smartphone for 1-2 days per week (${\beta}=-.205$, p=.026). Conclusion: Based on the results of this study, it is necessary to try to develop guidelines and programs to prevent smart phone overdependency in preschool children.

• Journal of Music and Human Behavior
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• v.14 no.1
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• pp.85-108
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• 2017

The purpose of this study was to examine how a therapeutic drumming intervention would impact middle school students with regard to school violence prevention. Participants were all in the third-year class of a middle school in Korea. A school music teacher and a music therapist designed and implemented the program collaboratively, and mainly used dyadic, synchronized, and improvisational drumming based on the Social Emotional Learning core competencies. A total of 65 students participated in a weekly 45-minute program for 10 weeks. Ten participants out of 65 were selected for interviews and the rest of the 55 participants were asked to fill out an open-ended survey. Content analysis of the survey and interviews produced 492 meaningful statements, which were categorized into seven themes: somatic responses to drumming, emotional processing, group cohesion, empathy, relationship with peers, self-esteem, and self-regulation. The findings indicated that dyadic, synchronized, and improvisational drumming may promote prosocial behaviors in students of this age. The author discussed that drumming produces physical input directly from the instruments, which prompts students to identify and empathize with their own or others' emotions. This study therefore suggests that collaborative work between school music teachers and music therapists may positively impact middle school students' prosocial behaviors, as they pertain to school violence in Korea.

• 한국노년학
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• v.41 no.3
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• pp.421-444
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• 2021

The purpose of this research is to examine the reciprocal relationships between depression and marital satisfaction among older couples. For longitudinal dyadic analysis, this study sets up a research model based on the Actor-Partner Interdependence Model, the Common Fate Model, and Autoregressive Cross-Lagged Model. Data came from four annual waves from the 10th year (2015) to the 13th year (2018) of the Korean Welfare Panel Survey and the final sample comprised a total of 1,383 married couples over 60 years of age in 2015. Structural Equation Modeling identified the reciprocal relationship between depression and marital satisfaction among older couples, with higher marital satisfaction of older couples leading to lower depression of husbands' and wives', and with higher depression of husbands' and wives' inducing lower marital satisfaction of the couples. Thus, this study suggested that longitudinal interplay between depression and marital satisfaction can lead to a vicious cycle. Based on these findings, the need to intervene at both the individual level and the couple level was discussed in order to reduce depression and improve marital satisfaction.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.677-680
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• 2008

The paper deals with the analysis of radiation characteristics of antenna in the multi-layered media structures. The dyadic Green's function for three layer medium is complex because the Green's functions belonging to the kernel of the integral equation are expressed as Sommerfeld integrals, in which surface wave effects are automatically included. When certain condition are met, the integral can be evaluated approximated by the method of Saddle-point integration. In this study, we propose a method to calculate a radiation pattern for several antennas by using the method of Saddle-point integration. Numerical results show how the radiation characteristics are affected by parameter of dielectric media.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.931-939
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• 2001

The slot coupling characteristics was analysed in a radial-line slot antenna for its design. The previously proposed waveguide model with a periodic boundary condition on its narrow walls and periodically arranged slots on its wide wall was used. The magnetic field integral equation and two dyadic Green\`s functions for respective regions was derived and the method of moments was used. To maximize the efficiency of numerical analysis and to extract singularities, two different kinds of basis functions, the entire domain basis function and the sub-domain one, are used. In addition, the Ewald sum technique for the rectangular waveguide and the Shanks transform for the half space were used to accelerate the computation of the slowly convergent potential Green\`s functions. Simulation results expressed the effects of the various design parameters on the slot coupling.