• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1391-1392
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• 2008

The modulation quality of the I/Q modulator in a wireless transmitter usually affects system performance and it mostly depends on both a nonlinearity and a distortion, from the third order intermodulation(IM3) signal and the imperfection features such as an input amplitude error and a local phase error, respectively. This paper focused on how much the Single Sideband Ratio(SSR), which indicates the signal distortion, changes according to the variation of the imperfection features. Since a desired signal, side band and IM3 signals at the I/Q modulator output are also represented with those power series coefficients and the imperfection features, the effects of the imperfection features on SSR can be clearly analyzed.

• Journal of Electrical Engineering and Technology
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• v.7 no.4
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• pp.570-575
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• 2012

In a wireless communication RF transmitter, the output of a quadrature modulator (QM) is distorted by not only the linear imperfection features such as in/quadrature-phase (I/Q) input gain imbalance, local phase imbalance, and local gain imbalance but also the nonlinear imperfection features such as direct current (DC) offset and mixer nonlinearity related to in-band spurious signal. In this paper, we propose the unified QM model to analyze the combined effects of the linear and nonlinear imperfection features on the performance of the QM. The unified QM model consists of two identical nonlinear systems and modified I/Q inputs based on the two-port nonlinear mixer model. The unified QM model shows that the output signals can be expressed by mixer circuit parameters such as intercept point and gain as well as the imperfection features. The proposed approach is validated by not only simulation but also measurement.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1992.03a
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• pp.83-102
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• 1992

As shear localization is observed in different deformation modes, an attempt is made to understand the conditions for shear localization in general deformation modes. Most emphasis in put upon the effects of pre-localization deformation mode on the onset of shear localization and all the other well-recognized effects of subtle constitutive features and imperfection sensitivity studied elsewhere are not investigated here. Rather, an approximate perturbation stability analysis is performed for simplified isotropic rigid-plastic solids subjected to general mode of homogeneous deformation. Shear localization is possible in any deformation mode if the material has strain softening. The incipient rate of shear localization and shear plane orientations are strongly dependent upon the pre-localization deformation mode. Significant strain softening is necessary for shear localization in homogeneous axisymmetric deformation modes while infinitesimal strain softening is necessary for shear localization in plane strain deformation mode. In any deformation mode, there are more than one shear plane orientation. Except for homogeneous axisymmetric deformation modes, there are two possible shear plane orientations with respect to the principal directions of stretching. Some well-known examples are discussed in the light of the current analysis.

• Steel and Composite Structures
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• v.5 no.1
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• pp.1-15
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• 2005

Important characteristics of the previously proposed reduced stiffness method and a summery of its design curves for the buckling of the axially loaded sandwich cylindrical shells is presented. Comparison of the lower bound obtained with FEM analysis with that from the reduced stiffness analysis shows that the proposed reduced stiffness method can provide safe lower bounds for the buckling of geometrically imperfect, axially loaded sandwich cylindrical shells. One of the attractive features of the reduced stiffness elastic lower bound analysis is that it provides safe estimates of buckling loads that do not depend on the specification of the precise magnitude of the imperfection spectra. As a result, designers can readily apply this method without being worried about possible geometrical imperfections that might be generated during fabrication and construction of sandwich cylindrical shells.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.570-572
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• 2008

The modulation quality of the I/Q modulator in a wireless transmitter usually affects system performance and it mostly depends on both a nonlinearity and a distortion, from the third order intermodulation($IM_3$) signal and the error components such as an input amplitude error and a local phase error, respectively. This paper focused on how much the Single Sideband Ratio(SSR), which indicates the signal distortion, changes according to the variation of the error components. Consequently, since a desired signal, side band signal at the I/Q modulator output are also represented with those power series coefficients and the error components, the effects of the error components on SSR to meet the EVM specification of the WPAN can be clearly analyzed.

• Journal of Fashion Business
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• v.7 no.5
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• pp.45-53
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• 2003

Rei Kawakubo is known for her provocative aesthetics: she often deliberately seeks beauty in what is seen by convention as taboo. With her highly informed and invariably provocative aesthetic, Rei Kawakubo has advanced historical forms of dress using radical functional and structural transpositions. She is considered as a pioneer showing firmly important elements of modern fashion design in her works by fashion journalists. In this paper, I'd like to analysis features of modern fashion design through Rei Kawakubo's works. I will analysis important elements of Rei Kawakuvo's design and devote study of the connection between the feature of her design and the feature of modern fashion design.

• Korean Journal of Childcare and Education
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• v.10 no.6
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• pp.291-311
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• 2014

This research is to understand young children ontologically by examining features of young children in the picture books for the early childhood. For the purpose, under the consultation with a picture book specialist and three level process of selection, 4 picture books were chosen as analytic objects. The study questions is as follows. What is ontological understandings on young children throughout picture books for the early childhood? Under this purpose the books chosen were John Burningham's , David Wiesner's , Hina Back's , Peter Sis's . The books went through dramaturgical coding and were thematised based on the theories of ontological phenomenology. Study results show that young child-being appearing in the picture-books are thematised as 'multi layered being with Ntwurf and Geworfenheit(Aldo)', 'responsible being risen above greed(Plotsam)', 'reflective being on face of others(Fairy of Jangsutang)', 'being who encourages educational response of adults.(Madlenka's Dog)' These results revealed that young child-being have features not different from (multi layered aspect of being), unique from(encouraging educational response), and beyond adult-being(responsibility and response towards others). Despite several limitations, this study helped understand the young children ontologically by revealing that they, not only as developmental beings with imperfection, dependence, and immaturity but as multi layered and requesting, responsible being, having the same features as adults and, at times, rise above adult-being.

• Cross-Cultural Studies
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• v.42
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• pp.23-46
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• 2016

This article focused on heterotopian spaces of modern Korea in the colonial era. This paper attempted to understand the features of heterotopia in the era. Heterotopia was slightly grotesque in modernity, but in the colonial era, people expected to realize the hope of contemporary society. Also, while analyzing discourses on heterotopia, this study identified another point of view on modernity in the era,. Pagoda Park, where March First Independence Movement was conducted and the psychiatric hospital East Ward Eighth, were heterotopian spaces at the times. Those spaces are represented as failure of modernity. Nevertheless, those spaces functioned as utopia, where people could speak freely on 'the independence'. But the governing system considered such speech as deceptive strange stories. Strange stories that inexplicably, revealed imperfection of the governing system and caused anxiety about the foundation of daily life. In conclusion, this article could provide understanding of another side of acceptance of modernity in the colonial era i.e., anxiety. It was revealed through the finding of heterotopia and analyzing discourses on heterotopia in the colonial Korea.