• 대한수학회지
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• 제35권4호
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• pp.881-890
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• 1998

Sufficient conditions for forced oscillations of the solutions of impulsive nonlinear parabolic differential-difference equations are obtained.

• 한국컴퓨터정보학회논문지
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• 제16권7호
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• pp.173-181
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• 2011

본 연구에서는 자아개념이 충동구매와 구매 후 감정반응에 어떤 영향을 미치는지 알아보고자 하였다. 이를 위해서 자아개념의 사회의존성-독립성에 따라 2개의 집단으로 나누어 충동구매와 구매 후 감정에 미치는 영향을 분석하였다. 충동구매는 계획성 정도에 따라 충동구매 집단과 비충동구매 집단으로 나누어 구매 후 감정을 비교하였다. 또한 심사숙고성-즉흥성 정도를 이용하여 자아개념과 구매 후 감정과의 관계를 재 검정하였다. 연구결과를 보면, 충동구매집단은 죄책감, 후회, 행복감에서 비충동구매 집단보다 높았고 자긍심에서는 비충동구매 집단이 높았다. 자아개념은 충동구매에 유의적 영향을 미쳤으며, 죄책감, 후회, 행복감에서 충동구매의 구매 후 감정에 미치는 영향을 조절하였다. 그러나 자긍심에 대해서는 조절효과가 나타나지 않았다. 이런 결과는 사회적으로 독립적인 자아개념을 가진 소비자들이 충동구매 후에 높은 부정적 감정(죄책감, 후회)과 함께 긍정적 감정(행복감)을 갖지만, 충동구매자체에 대해서는 바람직한 구매전략으로 보지 않고 있음을(낮은 자긍심) 나타낸다고 할 수 있다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.355-360
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• 2001

This study addresses a computational work of the impulsive wave which is discharged from the open end of a pipe. An initial compression wave inside the pipe is assumed to propagate toward atmosphere. The over pressure and wave-length of the initial compression wave are changed to investigate the characteristic values of the impulsive wave. The second order total variation diminishing (TVD) scheme is employed to solve the axisymmetric, compressible, unsteady Euler equations. The relationship between the initial compression wave form and impulsive wave is characterized in terms of the peak pressure of the impulsive wave and its directivity. The results obtained show that for the initial compression wave of a large wave-length the peak pressure of the impulsive wave does not depend on the over pressure of the initial compression wave, but for the initial compression wave of a very short wave-length, like a shock wave, the peak pressure of the impulsive wave is increased with an increase in the over pressure of the initial compression wave. The directivity of the impulsive wave to the pipe axis becomes significant with a decrease in the wave-length of the initial compression wave.

• 대한기계학회논문집B
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• 제20권7호
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• pp.2375-2385
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• 1996

As a compression wave is emitted from a duct, an impulsive wave generates and causes an impulsive noise that is at present a serious environmental noise pollution. In order to clarify the acoustic characteristics of the noise and to reduce their pressure levels, a series of model experiments were conducted on the impulsive waves emitted from an open end of a shock tube. The impulsive waves with various intensities were obtained by controlling the operation pressure ratio of the shock tube. Various kinds of silencers such as the exit boxes with baffle plates, were applied to the duct exit to reduce the impulsive noises. The effects of geometry of silencers and shock Mach number on the noise reduction were clarified. From the measurements of sound pressure level, it was found that installing the baffle plate into the exit box is effective in lowering the noise level at far fields, and that the recommendable geometries of silencer are L/D=1, H/D=1 and H/D=0.75.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1494-1498
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• 2007

Impulsive shooting noise is basically complex phenomenon which contains the linear and non-linear characteristics. For those reasons, numerical analysis of impulsive shooting noise has the difficulties in control of the numerical stability and accuracy on the simulation. In this research, Wave-number Extended Finite Volume Scheme (WEFVS) is applied to the numerical analysis of impulsive shooting noise. In the muzzle blast flow simulation, the generation of the precursor wave and the induced vortex ring are observed. Consequently, blast wave. vortex ring interaction and vortex ring. bow shock wave interaction are evaluated on the shooting process using the accurate and stable scheme. The sound generation in the interactions can be explained by the vorticity transport theorem. The shear layer is evolved behind the projectiles due to the jet flow. In these computations, the impulsive shooting noise is generated by the complex interaction with shooting process and is propagated to the far-field boundary. The impulsive shooting noise generation can be observed by the applications of WEFVS and analyzed by the physical phenomena.

• 한국정밀공학회지
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• 제25권10호
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• pp.107-114
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• 2008

The aim of this study is to obtain the useful design guideline for high impulsive force device with an isolation system by the analytic approach of dynamics characteristics. In this study, the high impulsive force system was modeled and analyzed in view of multi-body dynamics, and verified the modeling and analysis result by the experiment of the high impulsive force device. Additionally, the dynamic analysis was performed for the isolation system with the selected coefficients of elastic spring and damper selected. Experimental result for the high impulsive force device with the isolation system was compared and analyzed. From the result, it was confirmed that the design guideline for the isolation system of the high impulsive force device was useful.

• 한국통신학회논문지
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• 제30권9C호
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• pp.899-906
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• 2005

이 논문에서는 충격성 잡음 감쇄 채널에서 가장 비슷함을 바탕으로 최적 갈퀴수신기를 이끌어 내고, 얼개가 간단한 준최적 갈퀴수신기를 얻는다. 잡음이 충격성이면 충격성 환경을 고려한 갈퀴수신기가 정규 잡음에 최적화된 갈퀴수실기보다 성능이 좋다는 것을 모의실험으로 보인다. 또한, 갈퀴수신기의 가락 수가 늘어날수록, 충격성 환경에 알맞게 만든 갈퀴수신기는 성능이 나아지지만, 정규 잡음에 최적화된 갈퀴수신기는 충격성 환경에서 성능이 떨어짐을 보인다.

• 대한기계학회논문집B
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• 제21권9호
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• pp.1095-1104
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• 1997

When a high-speed railway train enters a tunnel, a compression wave is generated ahead of the train and propagates along the tunnel, compressing and accelerating the rest air in front of the wave. At the exit of the tunnel, an impulsive wave is emitted outward toward the surrounding, which causes a positive impulsive noise like a kind of sonic boom produced by a supersonic aircraft. With the advent of high-speed train, such an impulsive noise can be large enough to cause the noise problem, unless some attempts are made to alleviate its pressure levels. For the purpose of the impulsive noise reduction, the present study investigated the effect of a vertical bleed duct on the compression wave propagating into a model tunnel. Numerical results were obtained using a Piecewise Linear Method and testified by experiment of shock tube with an open end. The results showed that the vertical bleed duct reduces the maximum pressure gradient of compression wave front by about 30 percent, compared with the straight tunnel without the bleed duct. As the width of the vertical bleed duct becomes larger, reduction of the impulsive noise is expected to be greater. However the impulsive noise is independent of the height of the vertical bleed duct.

• 한국통신학회논문지
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• 제36권10B호
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• pp.1210-1215
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• 2011

이 논문에서는 다중경로 특성과 충격성 잡음이 있는 수중 통신 채널에 대해 확률밀도함수 정합 방법에 근거한 적응등화 알고리듬을 소개하고 결정 궤환을 적용한 확률밀도함수 정함 알고리듬을 제안하였다. 기존의 제곱평균오차 기반의 최소평균제곱 (LMS) 알고리듬은 수중통신 채널의 충격성 잡음과 다중경로 채널을 보상하지 못하는 현상을 보였다. 충격성 잡음에 효과적인 면역성을 보인 선형 확률밀도함수 정합 알고리듬도 열악한 다중경로 환경에서는 만족스럽지 못한 성능을 나타났다. 한편, 제안한 결정 궤환 구조의 비선형 확률밀도함수 정합 알고리듬은 수중 통신 채널의 다중경로 특성과 충격성 잡음에 대해 탁월한 강인성을 가짐을 모의실험을 통해 입증되었다.

• 한국의류학회지
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• 제26권3_4호
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• pp.379-389
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• 2002

The purposes of this study were 1) to examine the conceptual structure of purchasing situations and affective states, 2) and to fine out the relationships among impulsive buying behavior, purchasing situations, and affective states in boutiques. The questionnaire was completed by 345 boutiques customers in Busan. Demographics showed that the customers were higher educated and had higher incomes than the average consumer in Busan. Data were analysed by factor analysis, and t-test. First, the purchasing situation perceived by boutiques customers consisted of five factors; Crowding, Atmosphere/service, Exhausting/salesman's attire, Display, and Price. The affective states related to the impulsive buying behavior in boutiques composed of three factors; Pleasant, Unpleasant, and Insecure. Second, the impulsive buyer perceived Exhausting/salesman's attire and the pleasant affection in stores higher than the unimpulsive buyer, and the unimpulsive buyer made higher scores than the impulsive buyer in the situation of C개wding, Atmophere/service, and the Unpleasant affection at boutiques. The results showed that impulsive buyer was influenced by purchasing situations and affective states in stores. They provided informations about impulsive buying useful to consumer behavior researchers and retailers related to boutiques.