• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.3
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• pp.35-42
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• 2000

A cross-shaped microstripline-fed printed slot antenna having wide bandwidth Is presented in this paper. The proposed antenna is analyzed by using the Finite-Difference Time-Domain (FDTD) method. It was found that the bandwidth of the antenna depends highly on the length of the horizontal and vertical feedline as well as the offset position of the feedline. The maximum bandwidth of this antenna is from 1.975 GHz to 4.725 GHz, which is approximately 1.3 octave, for the VSWR $\leq$ 2. Experimental data for the return loss and the radiation pattern of the antenna are also presented. and they are in good agreement with the FDTD results.e FDTD results.

• Korean Journal of Optics and Photonics
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• v.11 no.1
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• pp.37-42
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• 2000

We have numerically solved rate-equations of semiconductor optical amplifier (SOA) to understand the characteristics of SOA. The rate-equations we have used can describe injection carrier density, amplified spontaneous emission and signal photon density in spatial and time domain by dividing the cavity into multi-section. We have investigated injection carrier density, amplified spontaneous emission and signal photon density as a function of position and time in the case of single channel input in the form of square pulse. Also we have analyzed the non-linear phenomena of SOA in the case of injecting multi-channel wavelengths as in WDM. Intermodulation distortion (IMD) caused by beat among channels has significant effects on the signal distortion as the channel spacing becomes narrower, and channel crosstalk becomes larger as the power of signals increases. In the case of the injection of another CW laser whose wavelength is far enough from the signal wavelengths, the crosstalk and the output signal distortion can be significantly reduced. duced.

• International Journal of Naval Architecture and Ocean Engineering
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• v.6 no.3
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• pp.562-577
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• 2014

A reliable steady/transient hydro-elastic analysis is developed for flexible (composite) marine propeller blade design which deforms according to its environmental load (ship speed, revolution speed, wake distribution, etc.) Hydro-elastic analysis based on CFD and FEM has been widely used in the engineering field because of its accurate results however it takes large computation time to apply early propeller design stage. Therefore the analysis based on a boundary element method-Finite Element Method (BEM-FEM) Fluid-Structure Interaction (FSI) is introduced for computational efficiency and accuracy. The steady FSI analysis, and its application to reverse engineering, is designed for use regarding optimum geometry and ply stack design. A time domain two-way coupled transient FSI analysis is developed by considering the hydrodynamic damping ffects of added mass due to fluid around the propeller blade. The analysis makes possible to evaluate blade strength and also enable to do risk assessment by estimating the change in performance and the deformation depending on blade position in the ship's wake. To validate this hydro-elastic analysis methodology, published model test results of P5479 and P5475 are applied to verify the steady and the transient FSI analysis, respectively. As the results, the proposed steady and unsteady analysis methodology gives sufficient accuracy to apply flexible marine propeller design.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.275-280
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• 2014

Leucine-responsive Regulatory Protein (Lrp) from Escherichia coli is an 18.8 kDa protein composed of 164 amino acids. Wild type Lrp (Lrp Wt) does not possess any tryptophan amino acid which has strong intrinsic fluorescence, whereas the mutant Lrp R145W contains a single tryptophan at the position 145 in the leucine-responsive domain. To investigate the fluorescence character, the Lrp R145W and Lrp Wt proteins were purified. The fluorescence intensity of Lrp R145W is much higher than that of wild type protein, and the intensity of Lrp R145W was decreased by binding to its specific DNA designed from ilvIH operon and to L-leucine. In addition, the tryptophan fluorescence intensity of Lrp R145W was strongly quenched by addition of acrylamide even in the least amount of concentration as well as by urea. The data obtained from this study may give valuable information on the three dimensional structure of Lrp R145W.

• Journal of the Korean Institute of Educational Facilities
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• v.27 no.2
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• pp.35-47
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• 2020

The need for communication is emphasized in decision making, design methods and processes for the educational environment that contain new curricula and learning methods. In this study, we tried to find the direction and agenda of learner-centered environment restructuring through the 'user-integrated platform' in which various subjects related to school space environment understand each other's position and overcome the barriers and prejudices of each sector. The project was planned in a 'bottom-up process' method that uncovered the singularities of the previous stage and led the main contents of the next stage. The various subjects who participated in the project shared their own experiences and different positions regarding the school space. At the workshop, the topics of the participating teams were divided into two categories. The teams in the category of the 'school culture and space' insisted innovation of 'the school culture' as a premise for the restructuring of the 'school space', and proposed schools with different interpretations of 'authority and rules of school', 'the meaning of learning and play' and 'the main character of school. The teams in the category of the 'school borders and spaces' focused on 'communication' and proposed schools containing 'emotional care of students', 'borders between schools and villages', 'village community schools', and 'interspace and niche time'. After the workshop, we were able to derive the direction and architectural strategy of the school space restructuring by analyzing the works of the participants. Through this study, we confirmed the possibility of translating user's ideas into the professional domain through careful planning, preparation, facilitation, and analysis in Participatory Design.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.10a
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• pp.702-704
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• 2017

In case of dismantling of nuclear power generation facility or radiation accident, the accurate information of gammaray source is essential for rapid decontamination. In order to more efficiently represent the position of the gamma ray to be removed, we create a spatial domain based on the real image. And we can perform decontamination of gamma-ray source more quickly by expressing the distribution of radiation source. The developed gamma ray imaging device overlaps with the visible image after gamma - ray detection and provides only two - dimensional image, but it does not show the distance information to the source. In this paper, we have developed a operation environment using the 3D visualization model for reporting effective decontamination operation.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.3
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• pp.290-295
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• 2011

On the basis of DCPA(Distance to Closest Point of Approach) and TCPA(Time to CPA), the conventional algorithms for collision avoidances have a drawback that the '72 CORLEGs(International Regulations for Preventing Collisions at Sea, 1972) has not taken into account to prevent collisions between ships. In this paper, the proposed algorithm decides whether the own ship is a give-way vessel or a stand-on vessel by observing the relative bearing of the encountered ship. To determine the ship position and time for collision avoidance, the proposed algorithm utilizes the ellipse model for ship safety domain. The computer simulation is done to represent the process of adversive behavior. Using the proposed method, the past maritime accident is analyzed. The proposed method can be effectively applied to collision avoidance by CORLEGs even when the target ship's navigational lights is invisible in poor weather and/or in the restricted visibility.

• Journal of Family Relations
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• v.21 no.4
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• pp.99-117
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• 2017

Objectives: The purpose of this study is investigate the influences of childhood abuse experience, discipline styles and social support on childcare efficacy according to socio-demographic backgrounds of childcare teachers. Method: For this study's purpose, 200 childcare teachers working at children's schools in J city were surveyed and analyzed for child abuse experience, discipline styles, social support and childcare efficacy. Frequency analysis, t-test, ANOVA and multiple regression analysis were used as study methods. Results: The results of this study are as follows. First, there were statistically significant differences in childhood abuse experiences according to the general characteristics of childcare teachers in the sub-domain of occupational position and marriage status. Second, childcare efficacy and social support were positively correlated, and discipline styles and childcare efficacy were negatively correlated, but there was no correlation between social support and abuse experience. Third, general teaching efficacy regarding childcare efficacy showed a statistical influence of physical abuse, which is a sub-variable of childhood abuse experience. The general efficacy of teaching showed a statistically significant influence on logical discipline and coercive discipline, which are sub-variables of discipline methods. The general teaching efficacy in terms of childcare efficacy showed a statistically significant influence in the family variable which is a sub-variable of social support. The personal teaching efficacy within childcare efficacy showed a statistically significant influence in the logical discipline, a sub-variable of physical abuse, and disciple styles, a sub-variable of childhood abuse experience. Conclusion: From these findings, childcare teachers' childhood abuse experience was a factor affecting childcare efficacy in discipline, social support, and sub-variables. Therefore, it is necessary to remedy the effects of childhood abuse experience, encourage appropriate discipline styles, and to encourage social support in order to improve the childcare efficacy among childcare teachers.

• Ocean Systems Engineering
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• v.11 no.1
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• pp.17-42
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• 2021

Articulated loading platforms (ALPs) belongs to a class of offshore structures known as compliant. ALP motions have time periods falling in the wind excitation frequency range due to their compliant behaviour. This paper deals with the dynamic behavior of a double hinged ALP subjected to low-frequency wind forces with random waves. Nonlinear effects due to variable submergence, fluctuating buoyancy, variable added mass, and hydrodynamic forces are considered in the analysis. The random sea state is characterized by the Pierson-Moskowitz (P-M) spectrum. The wave forces on the submerged elements of the platform's shaft are calculated using Morison's Equation with Airy's linear wave theory ignoring diffraction effects. The fluctuating wind load has been estimated using Ochi and Shin wind velocity spectrum for offshore structures. The nonlinear dynamic equation of motion is solved in the time domain by the Wilson-θ method. The wind-structure interactions, along with the effect of various other parameters on the platform response, are investigated. The effect of offset of aerodynamic center (A.C.) with the center of gravity (C.G.) of platform superstructure has also been investigated. The outcome of the analyses indicates that low-frequency wind forces affect the response of ALP to a large extent, which otherwise is not enhanced in the presence of only waves. The mean wind modifies the mean position of the platform surge response to the positive side, causing an offset. Various power spectral densities (PSDs) under high and moderate sea states show that apart from the significant peak occurring at the two natural frequencies, other prominent peaks also appear at very low frequencies showing the influence of wind on the response.

• BMB Reports
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• v.55 no.4
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• pp.192-197
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• 2022

Cell signals for growth factors depend on the mechanical properties of the extracellular matrix (ECM) surrounding the cells. Microtubule acetylation is involved in the transforming growth factor (TGF)-β-induced myofibroblast differentiation in the soft ECM. However, the mechanism of activation of α-tubulin acetyltransferase 1 (α-TAT1), a major α-tubulin acetyltransferase, in the soft ECM is not well defined. Here, we found that casein kinase 2 (CK2) is required for the TGF-β-induced activation of α-TAT1 that promotes microtubule acetylation in the soft matrix. Genetic mutation and pharmacological inhibition of CK2 catalytic activity specifically reduced microtubule acetylation in the cells cultured on a soft matrix rather than those cultured on a stiff matrix. Immunoprecipitation analysis showed that CK2α, a catalytic subunit of CK2, directly bound to the C-terminal domain of α-TAT1, and this interaction was more prominent in the cells cultured on the soft matrix. Moreover, the substitution of alanine with serine, the 236th amino acid located at the C-terminus, which contains the CK2-binding site of α-TAT1, significantly abrogated the TGF-β-induced microtubule acetylation in the soft matrix, indicating that the successful binding of CK2 and the C-terminus of α-TAT1 led to the phosphorylation of serine at the 236th position of amino acids in α-TAT1 and regulation of its catalytic activity. Taken together, our findings provide novel insights into the molecular mechanisms underlying the TGF-β-induced activation of α-TAT1 in a soft matrix.