• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.161-168
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• 2009

There are many research for efficient, robust and invisible watermarking system that protects the digital contents like a image and animation according to growth of IT industry. First of all, frequency domain watermarking system like DWT(Descrete Wavelet Transform) is excellent because of minimum loss of original image and robustness of external attack. But, if we raise the insertion strength of watermark, then blazing of image occurs on existing DWT watermarking system and we should have a regular square image. In this study, we research the overflow check for preventing image from blazing and a robust and invisible watermarking algorithm. And we research a free-size DWT watermarking system using padding bytes, without a dependency of size.

• Proceedings of the Safety Management and Science Conference
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• 2011.11a
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• pp.717-725
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• 2011

This study carried out surveys for 197 nail shop practitioners and 195 customers 1) to study the real condition of their hygiene awareness and safety consciousness and 2) to grasp their awareness of the necessity of legislating a related bill so as to build an independent domain of business and to propose data on the national qualification system of nail care. As a result, it was found that the level of the nail care practitioners' experiences of safety education was very low, and that the customers attached importance to the necessity of nail salon practitioners' certificate and license and the nail treatment-related bill more than the nail care practitioners themselves. In conclusion, the preparation of a nail art-related bill is required at the state level for the management of the safety and hygiene of national health, and systematic and regular education related to hygiene should be carried out.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.4
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• pp.38-44
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• 2004

The motion response analysis of a submerged elliptic cylinder in waves is presented and the elliptic cylinder is a simplification of the section of submarine in this paper. The method is based on boundary integral method and two-dimensional 3 degree motions are calculated in regular harmonic waves. The fully nonlinear free surface boundary condition is assumed in an numerical domain and this solution is matched along an assumed boundary as a linear solution composed of transient Green function, The large amplitude motions of an elliptic cylinder are directly simulated and effects of wave frequency, wave amplitude and the distance from buoyancy center to gravity center are discussed.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2001.05a
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• pp.163-167
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• 2001

Modem stag setting construction method is tend to deversity and difficult to take a regular form. Each production is consituted by interpretion of the producer. It has been reproducting a new work of production. The domestic of large stage system and play conditions other stage's variety structure or divert various of reality conversion that how to used to give attention to reality. We have a stage plan a part of stage domain and in consideration of conversion system through a play stage's plan construction and purpose basic data in other to supply.

• International Journal of Naval Architecture and Ocean Engineering
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• v.4 no.3
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• pp.281-290
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• 2012

Hydrodynamic analysis of a surface-piercing body with an open chamber was performed with incident regular waves and forced-heaving body motions. The floating body was simulated in the time domain using a 2D fully nonlinear numerical wave tank (NWT) technique based on potential theory. This paper focuses on the hydrodynamic behavior of the free surfaces inside the chamber for various input conditions, including a two-input system: both incident wave profiles and forced body velocities were implemented in order to calculate the maximum surface elevations for the respective inputs and evaluate their interactions. An appropriate equivalent linear or quadratic viscous damping coefficient, which was selected from experimental data, was employed on the free surface boundary inside the chamber to account for the viscous energy loss on the system. Then a comprehensive parametric study was performed to investigate the nonlinear behavior of the wave-body interaction.

• Journal of the Korean Mathematical Society
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• v.53 no.6
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• pp.1211-1223
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• 2016

Let M be an n-dimensional $K{\ddot{a}}hler$ manifold with positive holomorphic bisectional curvature and let ${\Omega}{\Subset}M$ be a pseudoconvex domain of order $n-q$, $1{\leq}q{\leq}n$, with $C^2$ smooth boundary. Then, we study the (weighted) $\bar{\partial}$-equation with support conditions in ${\Omega}$ and the closed range property of ${\bar{\partial}}$ on ${\Omega}$. Applications to the ${\bar{\partial}}$-closed extensions from the boundary are given. In particular, for q = 1, we prove that there exists a number ${\ell}_0$ > 0 such that the ${\bar{\partial}}$-Neumann problem and the Bergman projection are regular in the Sobolev space $W^{\ell}({\Omega})$ for ${\ell}$ < ${\ell}_0$.

• International Journal of Naval Architecture and Ocean Engineering
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• v.12 no.1
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• pp.297-313
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• 2020

An Arctic Spar is characterized by its conical shape near the waterline. In this case, the nonlinear effects from its irregular hull shape would be significant if there is either a large amplitude floater motion or steep wave conditions. Therefore, in this paper, the nonlinear effects of an Arctic Spar are numerically investigated by introducing a weakly nonlinear time-domain model that considers the time dependent hydrostatic restoring stiffness and Froude-Krylov forces. Through numerical simulations under multiple regular and irregular wave conditions, the nonlinear behavior of the Arctic Spar is clearly observed, but it is not shown in the linear analysis. In particular, it is found that the nonlinear Froude-Krylov force plays an important role when the wave frequency is close to the heave natural frequency. In addition, the nonlinear hydrostatic restoring stiffness causes the structure's unstable motion at a half of heave natural period.

• Advances in nano research
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• v.14 no.5
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• pp.399-407
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• 2023

As Sensor plays an important part in day-to-day life. Sensors are used almost in each domain wherein humans are not able to sense or measure some parameters. Say from sensing a real-time activity of a person to sensing the tiny molecules of any gas or structures. Now sensors combined with advanced fabrication techniques with nanotechnology can be said as a game-changing combination. As the modern world is evolving every minute, the size of the components, instruments, and different equipment is shrinking rapidly. For example, the sensor or any other element which was used 10 years ago is reduced up to 5 times its original size and all of this is possible because of continuous advancement done in the manufacturing and fabrication techniques that are being used nowadays. Apart from this, it is not necessary that the term nano should only justify the size of the sensor. Nanotechnologically fabricated, refers to a sensor or any other element which may be large enough as compared to the regular one but they may be structured using some nano-particles.

• Journal of the Korean Mathematical Society
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• v.61 no.4
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• pp.797-836
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• 2024

We consider the following strongly damped wave equation on ℝ³ with memory u_tt - αΔu_t - βΔu + λu - ∫₀^∞ κ'(s)∆u(t - s)ds + f(x, u) + g(x, u_t) = h, where a quite general memory kernel and the nonlinearity f exhibit a critical growth. Existence, uniqueness and continuous dependence results are provided as well as the existence of regular global and exponential attractors of finite fractal dimension.

• Journal of Gifted/Talented Education
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• v.22 no.1
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• pp.23-37
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• 2012

The purpose of this study is to design a more satisfactory and efficient teaching strategy for the gifted by comparing teaching type and learning environment preferred by the gifted with that preferred by normal students. As a result, the following findings are obtained. First, while the normal class students show higher preference for clarification and organization, gifted students prefer for diversification and specialization. Second, with the respect to the gender-related forms of mathematics classroom environment, the overall female preference and the average score are higher, indicating significant difference in the area is only a psychological domain. Third, compared to the regular classroom, the gifted have significantly different preference for teaching method, classroom and teachers' attitude between in the gifted class and regular class.