• Kyungpook Mathematical Journal
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• 제48권4호
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• pp.613-622
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• 2008

In this article we introduce some difference sequence spaces defined by Orlicz function and study different properties of these spaces like completeness, solidity, symmetricity etc. We establish some inclusion results among them.

• Kyungpook Mathematical Journal
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• 제53권3호
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• pp.319-332
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• 2013

The sequence space $m(M,{\phi})^F$ of fuzzy real numbers is introduced. Some properties of this sequence space like solidness, symmetricity, convergence-free etc. are studied. We obtain some inclusion relations involving this sequence space.

• 천문학회지
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• 제54권4호
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• pp.113-119
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• 2021

It is difficult for observers to conduct an optical alignment at an observatory without the assistance of an optical engineer if optomechanical parts are to be replaced at night. We present a practical tilt correction method to obtain the optimal optical alignment condition using the symmetricity of optical aberrations of a wide-field on-axis telescope at night. We conducted coarse tilt correction by visually examining the symmetry of two representative star shapes obtained at two guide chips facing each other, such as east-west or north-south pairs. After coarse correction, we observed four sets of small stamp images using four guide cameras located at each cardinal position by changing the focus positions in 10-㎛ increments and passing through the optimum focus position in the range of ±200 ㎛. The standard deviation of each image, as a function of the focus position, was fitted with a second-order polynomial function to derive the optimal focus position at each cardinal edge. We derived the tilt angles from the slopes converted by the distance and the focus position difference between two paired guide chip combinations such as east-west and north-south. We used this method to collimate the on-axis wide-field telescope KMTNet in Chile after replacing two old focus actuators. The total optical alignment time was less than 30 min. Our method is practical and straightforward for maintaining the optical performance of wide-field telescopes such as KMTNet.

• 대한기계학회논문집
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• 제18권3호
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• pp.690-700
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• 1994

The effects of thermal stratification on the flow of a stratified fluid past a circular cylinder were examined in a wind tunnel. In order to produce strong thermal stratifications, a compact heat exchanger type variable electric heater is employed. Linear temperature gradient of up to $250^{\circ}C/m$ can be well sustained. The velocity and temperature profiles in the cylinder wake with a strong thermal gradient of $200^{\circ}C/m$ were measured and the smoke wire flow visualization method was used to investigate the wake characteristics. It is found that the temperature field effects as an active contaminant, so that the mean velocity and temperature profiles can not sustain their symmetricity about the wake centerline when such a strong thermal gradient is superimposed. It is evident that the turbulent mixing in the upper half section is stronger than that of the lower half of the wake in a stably stratified flow.

• 대한자기공명의과학회:학술대회논문집
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• 대한자기공명의과학회 2001년도 제6차 학술대회 초록집
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• pp.133-133
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• 2001

Purpose： To determine the relationship between anatomical variation at A-com. artery area an hemodynamically induced aneurysm-mimicking findings on 3D-TOF MRA clinically a experimentally. Method： Sixty-two patients who had no aneurysm at A-com artery on DSA were evalua with MRA. MRA was performed with 1.5T MR machine(Vision, Siemens). Scan parameters o MRA included TR/TE/FA=30/6.4/25$\psi$$\circledR$˙¡, 512＊192 of matrix with MIP technique. The occurrence of signal defect at shoulder area of bifurcated A-com artery on MRA was evalua for the relationship between the symmetricity of bilateral ACA and the patency of A-c artery. DSA images were acquired at both ICA and VA. To analyze hemodynamical facto of signal defect, experimental studies of MRA and DSA were peformed with elastic silic phantom using conducting pulsatile pump. We also compared the results with those o computational fluid dynamics(CFD).

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.218-224
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• 2011

A supersonic inlet at angle of attack has anti-symmetric pressure distribution, and it can make flow instability and structural problem. In this study, numerical analysis of three-dimensional inviscid flow was conducted under various throttle ratio and angle of attack conditions. Throttle ratio was defined as the ratio of the exit area to the smallest cross section area at inlet, and the ratio is controlled from 0 to 2.42. At various angle of attack, the characteristics of steady and unsteady flow around supersonic inlet is observed under different throttling ratios. From these results, pressure recovery curves and pressure history curves were plotted by post processing. Using pressure history data, FFT analysis is also carried out. Through these processes, it shows the tendency of pressure distribution anti-symmetricity and changing dominant frequency as increasing angle of attack.

• Kyungpook Mathematical Journal
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• 제50권3호
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• pp.389-397
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• 2010

In this paper we introduce the new generalized difference sequence space $\ell_\infty$($\Delta_v^n$, M,p,q,s), $\bar{c}$($\Delta_v^n$,M,p,q,s), $\bar{c_0}$($\Delta_v^n$,M,p,q,s), m($\Delta_v^n$,M,p,q,s) and $m_0$($\Delta_v^n$,M,p,q,s) defined over a seminormed sequence space (X,q). We study some of it properties, like completeness, solidity, symmetricity etc. We obtain some relations between these spaces as well as prove some inclusion result.

• 전자공학회논문지S
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• 제34S권2호
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• pp.79-93
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• 1997

This paper presents a linear shift-invariant system euqivalent to morphological dilation for a memoryless uniform source in the sense of the power spectral density function, and comares it with dialtion. This equivalent LSI system is found through spectral decomposition and, for dilation and with windwo size L, it is shown to be a finite impulse response filter composed of L-1 delays, L multipliers and three adders. Th ecoefficients of the equivalent systems are tabulated. The comparisons of dilation and its equivalent LSI system show that probability density functions of the output sequences of the two systems are quite different. In particular, the probability density functon from dilation of an independent and identically distributed uniform source over the unit interval (0, 1) shows heavy probability in around 1, while that from the equivalent LSI system shows probability concentration around themean vlaue and symmetricity about it. This difference is due to the fact that dilation is a non-linear process while the equivalent system is linear and shift-ivariant. In the case that dikation is fabored over LSI filters in subjective perforance tests, one of the factors can be traced to this difference in the probability distribution.

• 복식
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• 제17권
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• pp.83-91
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• 1991

I observed the meaning and the symbolic charaeters about the color and style of clothes appearing at "GER GA JAP BOK GO" written by Kyu Soo Park. The black color of Hyun Eui as a ceremonial dress of man symbolizes Heaven and Virtue. The yellow color of Whang Sang as a ceremonial dress of man symbolizes the Earth and the Impartiality. The blue or black decoration line over white ground of Sim Eui as ordinary dress of man symbolizes also Filial Piety. In woman ordinary upper garment, So Eui, black texture edging with blue line implies the mutual symmetricity with her husband's. Besides, white color texture lining So Eui symbolical to a Devine Nature and Homage implies also the deep concealment of feminine body. The black ground color of child dress "Chi Po Eui" symbolizes Naivety, and the red silk color of it's decoration line, belt and tress ornaments implies the praise of the Virtue & Learning and also "Expel the Evil" of our traditional national characteristics. As described above the meaning and symbolic characters about the color and style of clothes appearing at "GER GA JAP BOK GO" has a very Chinese disposition, but it's author Kyu Soo Park modified somewhat to be in harmony with the real social situation of our Country during that latest stage of Yi Dynasty, because he was one of the prominent pragmatist at that time.

• 대한기계학회논문집
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• 제18권5호
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• pp.1322-1329
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• 1994

The effect of thermal stratification on the stratified flow past a circular cylinder was examined in a wind tunnel. Turbulent intensities, the rms values of temperature and turbulent convective heat flux as well as the velocity and temperature profiles in the cylinder wake with a strong thermal gradient of $200^{\circ}C/m$ were measured by using a hot-wire and cold-wire combination probe. It is found that the temperature field affects as an active contaminant, so that the vertical growth of vortical structure is suppressed and the strouhal number decreases with increasing the extent of stratification. And also, the wake structure can not sustain their symmetricity about the wake centerline and vertical turbulent motion dissipates faster than that of the neutral case when such a strong thermal gradient is superimposed. It is evident that the turbulent mixing in the upper half section is stronger than that of the lower of the wake in a stably stratified flow because the turbulent intensities and convective heat flux in the upper half section are larger than those of the lower half of the wake.