• Progress in Superconductivity
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• v.2 no.2
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• pp.65-70
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• 2001

$Pb/Bi_2Sr_2CaCu_2O_{8+\delta}$-single-crystal junctions with the tunneling direction along the c axis of the crystal were fabricated to obtain an s-wave-superconductor/d-wave-superconductor Josephson junctions. The tunneling R (T) curves and current-voltage characteristics show distinct features which can be explained only under the assumption that the order parameter of high-$T_c/Bi_2Sr_2CaCu_2O_{8+{\delta}}$ superconductors has a pure d-wave symmetry, which is in contrast to the case of $YBa_2Cu_3O_{7+{\delta$}}$erconductors where a minor s-wave component is also present..

• Bulletin of the Korean Mathematical Society
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• v.52 no.6
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• pp.1945-1962
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• 2015

This paper is mainly concerned with the formation of delta standing wave for the scalar conservation law with a linear flux function involving discontinuous coefficients by using the self-similar viscosity vanishing method. More precisely, we use the self-similar viscosity to smooth out the discontinuous coefficient such that the existence of approximate viscous solutions to the delta standing wave for the Riemann problem is established and then the convergence to the delta standing wave solution is also obtained when the viscosity parameter tends to zero. In addition, the Riemann problem is also solved with the standard method and the instability of Riemann solutions with respect to the specific small perturbation of initial data is pointed out in some particular situations.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1809-1810
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• 2007

본 논문에서는 뇌파인식을 위한 입력패턴을 추출하고 패턴 인식을 위한 뇌파 학습 알고리즘을 설계하였다. 입력패턴의 구성은 일반적인 상황에서 인식률을 더욱 높이기 위하여 기존의 Alpha-wave, Beta-wave, Theta-wave, Delta-wave등의 비율을 비교하는 방식에서 Delta-wave와 Theta-wave의 합, Alpha-wave, Delta-wave와 Theta-wave의 합에 Alpha-wave로 나눈 값, Beta-wave의 4가지 입력패턴으로 구성하였다. 그리고 신경망의 한 종류인 역전파 알고리즘을 이용하여 동일 조건이나 비슷한 조건에서의 수면과 비수면의 구분이 아닌 각기 다른 조건 상태에서의 수면과 비수면에 대한 패턴분류를 시뮬레이션 하였고 일반적인 조건에서도 감성 상태를 분류 할 수 있음을 보였다.

• Journal of Society of Preventive Korean Medicine
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• v.4 no.2
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• pp.214-234
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• 2000

This study was carried to identify whether acupuncture of several acupuncture points can affect the brain and to observe which aspects appear in EEG mapping, using electroencephalography. Those results are as follows ; 1. The pattern of resting computerized EEG map in intact human is appered normal 2. Each Acupuncture in Kwan Weon or Jog Sam Ri meridian points bring about the increase in $\theta,\;\alpha-wave$ activity and at various area of the cerebrium and the decrease in $\delta,\;\beta-wave$ activity. It strands to reason that brain function is elevated On the other hand , synchronous acupuncture bring about the decrease of brain function in view of the decrease of $\delta,\;\theta-wave$ activity at frontal area, and the unstable brain state in view of the increase of $\beta-wave$ activity. 3. Acupuncture in Hyeon Jong meridian point bring about the increase of $\delta,\;\theta-wave$ activity at frontal area and $\beta-wave$ activity at temporal area. From these we deduce that brain function is declined and brain is unstable. Synchronous acupuncture with other meridian points reversly showed that brain function is elevated. 4. Synchronous acupuncture in Kwan Weon , Jog Sam Ri, Hyeon Jong bring about the decrease of the brain function and the unstable brain state, showing the pattern of increased $\delta,\;\theta-wave$ activity at frontal, parietal area, and increased $\beta-wave$ activity at temporal area.

• Convergence Security Journal
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• v.2 no.2
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• pp.155-164
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• 2002

A design implemented the $\delta$SAcc234bit Mask Data Insertion algorithm that can let the Mask which commercialized Wave Steganography had improved the problem that a filter ring was able to easily become and raised Capacity and extend the width that Cover-data was alternative. Also, it applied 3-Tier file encryption algorithm with a proposal in order to improve a security level of Mask. 3-Tier file encryption algorithm is the algorithm that a specific pattern improved the problem that appeared in Ciphertext according to a file. A design implemented the StegoWaveK model carried out Wave Steganography, using $\delta$SAcc234bit Mask Data Insertion algorithm and the 3-Tier file encryption algorithm that proposed in this paper.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.121-126
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• 2006

Modern Ocean wave forecasting systems predict the mean sea state, as characterized by the wave spectrum, in a box of size ${\Delta}x{\Delta}y$ surrounding a grid point at location x. It is shown that this approach also allows the determination of deviations from the mean sea state, i.e. the probability distribution function of the surface elevation. Hence, ocean wave forecasting may provide valuable information on extreme sea states.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.6
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• pp.1800-1805
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• 2008

Shiro-abhyanga is one of treatments of Ayurveda, which is the ancient system of health care and medicine in India. In this essay, I examined the effect of Shiro-abhyanga for relaxing stress of women in twentieth by the means of the brain wave test. The brain wave test showed that Shiro-abhyanga reduced Delta and Theta waves of the left brain but increased $\alpha$, SMR, Low-$\beta$ waves of the right brain. Delta and Theta waves are usually found in sleeping time. Their high measurement in awakening instructs the stress and depressing situations of objects. However the treatment of Shiro-abhyanga made the decrease of Delta and Theta waves and the increase of Alpha wave in working time. Alpha wave appears while objects are comfortable and peaceful from the relaxation of body and mind. Therefore the growth of Alpha wave says that the treatment of Shiro-abhyanga has an effect on mitigation of stress.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.30-34
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• 2003

For an inhomogeneous superconductor, we reveal a relation of an observed superconducting gap, $\Delta$$_{obs}$ and the intrinsic true gap, $\Delta$$_{i}$, $\Delta$$_{obs}$(equation omitted) where band filling, 0＜$\rho$<$\leq$1. $\Delta$$_{obs}$ is the effect of measurement when 0＜$\rho$＜1. The true gap is observed only when $\rho$=1. Parring symmetry analyzed by a coherence-peak shape of density of states, observed in B $i_2$S $r_2$CaC $u_2$ $O_{8}$＋$\chi$ superconductors, is s- wave.X> $O_{8}$＋$\chi$ superconductors, is s- wave. wave.

• Journal of Korean Ophthalmic Optics Society
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• v.6 no.2
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• pp.11-16
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• 2001

The polariscope to measure :he stress in lens was made up quarter-wave plate polarizer and we analyzed two components of light's wave $E_1$ and $E_2$ following the steps. It is clear that the principal-stress difference ${\sigma}_1-{\sigma}_2$ can be determined in 2-D model if fringe order N is measured each point in sample moreover. the optical axes of sample coincide with the principal-stress directions. The birefringence acted to a light wave and a phase retardation were in proportioned to the principal-stressed difference (${\sigma}_1-{\sigma}_2$) and the intensity of final light wave was proportioned to $sin^2({\Delta}/2)$, when ${\Delta}/2=n^{\pi}$ (n=0, 1, 2, ...) and the extinction occurs. As a experimental result, the extinction band shifted owing to a magnitude of lens' external stress.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.3
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• pp.145-152
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• 2001

Low Rayleigh number thermal convection in a fluid layer confined between two-infinite horizontal walls kept at spatially sinusoidal temperature distributions, T_L=T_m+\Delta T\sin \kappax,\;T_U=T_m+\Delta T\sin(\kappax-\beta)$, is theoretically investigated by a regular perturbation expansion method. For small wave numbers, an upright cell is formed between the two walls at $\beta$=0. The cell is tilted, as the phase difference increases, and a flow with tow counter-rotating eddies occurs at $\beta=\pi$. when the wave number is large, isolated eddies are formed near the lower and upper walls, for all the phase differences. There exists a wave number at which maximum heat transfer rate at the walls occurs, at each of the phase differences. And the wave number increases with increase of the phase difference. for a fixed wave number, the heat transfer rate decrease with increase of the phase difference.