• Korean Journal of Mathematics
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• v.17 no.3
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• pp.331-340
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• 2009

We show the existence of nonconstant periodic solution for the nonlinear Hamiltonian systems with some nonlinearity. We approach the variational method. We use the critical point theory and the variational linking theory for strongly indefinite functional.

• Korean Journal of Mathematics
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• v.16 no.1
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• pp.85-90
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• 2008

We consider Fourier multiplier operators whose symbols satisfy a generalization of $H{\ddot{o}}rmander^{\prime}s$ condition and establish their Sobolev-type mapping properties on the homogeneous Besov-Lipschitz spaces by making use of a continuous characterization of Besov-Lipschitz spaces. As an application, we derive Sobolev-type imbedding theorem.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2006.08a
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• pp.8-9
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• 2006

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.231-236
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• 2000

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2002.11a
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• pp.95-101
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• 2002

• The Science & Technology
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• v.8 no.12 s.79
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• pp.61-64
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• 1975

An expression for the vibrational frequency of diatomic molecular is obtained by using molecular gas temperature T and molecular gas mean-free path λ. And when λ/T →2.59, beca use of the damped vibration, a diatomic molecular gas is Impeded about transportation. If transfortation is not attained with this condition, rectilinear motion of a diatomic molecular gas can't maintain for the equilibrium state.

• Communications of the Korean Mathematical Society
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• v.34 no.1
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• pp.145-154
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• 2019

The notion of hypercyclicity was localized by J-sets and in this paper, we will investigate for an equivalent condition through the use of open sets. Also, we will give a J-class criterion, that gives conditions under which an operator belongs to the J-class of operators.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.3
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• pp.361-368
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• 2011

Purpose : The aims of this study was to identify the activation of the mirror neuron system during action observation in people with stroke and the difference between left hemisphere and right hemisphere and to provide possibility of the use of action observation as a clinical method for improving motor function after stroke. Methods : Seventeen participants were asked to observe 3 different stimulation conditions for 80 seconds. A 30 second rest period was given between stimulations. Electroencephalogram(EEG) signals from electrodes on the participant's scalp were recorded during action observation. The activation of the mirror neuron system(MNS) between the picture observation condition and action observation condition was compared with a paired t-test. An independent t-test was used to compare difference between C3 and C4 on the activation of the mirror neuron system in the action observation condition. Results : Result of paired t-test showed a significantly decreased log ratio in the activation of the mirror neuron system in the action observation condition compared to the picture observation condition. Result of the independent t-test indicated no significant differences in the activation of the mirror neuron system in the right and left hemisphere. Conclusion : The mirror neuron system showed greater activation in the action observation condition than in the picture observation condition and activation in the both hemisphere during action observation. We conclude that these findings suggest that this may possibly be an efficient clinical intervention method for improving motor function.

• Korean Journal of Adult Nursing
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• v.12 no.1
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• pp.5-16
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• 2000

The aim of this study was to investigate the differences in the level of disease condition and ADL by self-efficacy in patients with rheumatoid arthritis. The subjects of the study consisted of eighty-four outpatients with rheumatoid arthritis at a university hospital in Taegu between July 20, 1999 and August 25, 1999. The instruments used in this study were the self-efficacy developed by Lorig et al. (1989), the pain scale developed by Lee and Song(1987), the erythrocyte sedimentation rate(ESR), the pain joint count to measure disease condition scale, and the ADL scale developed by Katz et al. (1970) and Barthel(1973). Analysis of data was done by use of descriptive statistics: Pearson Correlation, Chi-square test, t-test, ANOVA and Scheffe, with the SPSS program. The major findings can be summarized as follows: 1. The first hypothesis, "There will be differences in the level of disease condition by self-efficacy in patients with rheumatoid arthritis" was partially supported. 1-1. "There will be differences in the level of pain by self-efficacy in patients with rheumatoid arthritis" was supported(F=3.422, p=.037). 1-2. "There will be differences in the level of ESR by self-efficacy in patients with rheumatoid arthritis" was the Disease Condition and supported (F=3.314, p=.041). 1-3. "There will be differences in the level of pain joints count by self-efficacy in patients with rheumatoid arthritis" was rejected(F=2.602, p=.080). 2. The second hypothesis, "There will be differences in the level of ADL by self-efficacy in patients with rheumatoid arthritis" was supported(F=7.067, p=.001). With the above results, it can be concluded that the higher level of self-efficacy contributed to the better level of disease condition and ADL in patients with rheumatoid arthritis. Therefore, by providing nursing intervention to promote the level of self-efficacy of rheumatoid arthritis patients with low self-efficacy, disease condition and ADL would be much better.

• Ocean Systems Engineering
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• v.5 no.1
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• pp.1-19
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• 2015

The water jetting system for a jack-up spudcan requires the suitable design considering the platform/spudcan particulars, environments, and soil conditions, either the surficial clay or surficial sand. The usage of water jetting depends critically on soil conditions. The water jetting is usually used for the smooth and fast extraction of the spudcan in the surficial clay condition. It is also required for inserting spudcan up to the required depth in the surficial sand condition, which is investigated in this paper. Especially, it should be very careful to use the water jetting during an installation of spudcan in the surficial sand condition, because there is a risk of overturning accident related to the punch-through. Therefore, in this study, the effect of water jetting flow rate and time on the change of soil properties and penetration resistance is analyzed to better understand their interactions and correlations when inserting the spudcan with water jetting in surficial sand condition. For the investigation, a wind turbine installation jack-up rig (WTIJ) is selected as the target platform and the multi layered soil (surficial sand overlaying clays) is considered as the soil condition. The environmental loading and soil-structure interaction (SSI) analysis are performed by using CHARM3D and ANSYS. This kind of investigation and simulation is needed to decide the proper water jetting flow rate and time of spudcan for the given design condition.