• 한국콘텐츠학회논문지
• /
• 제6권4호
• /
• pp.11-18
• /
• 2006

본 논문에서는 두 가지 새로운 임펄스 잡음 검출기를 설계하고 총변량(total variation) 최적화를 통하여 영상에 존재하는 임펄스 잡음을 제거하는 방법을 제안한다. 설계된 임펄스 잡음 검출기는 적응 미디언 필터(AMF:Adaptive Median Filter)를 기반으로 하고 있으며 기존의 검출기에 비해 잡음검출의 정확도가 높고 영상의 디테일 정보를 잡음으로 오인하는 확률을 줄였다. 또한 제안하는 검출기는 잡음발생 확률에 무관하게 우수한 성능을 유지한다. 영상에서의 잡음제거는 제안된 검출기에 의해 얻어진 잡음후보 화소에 대해서만 총변량 최적화를 적용하므로 불필요한 계산을 줄이고 영상의 경계선을 잘 보존하면서 잡음을 제거할 수 있다. 실험결과 제안하는 2단 구조의 잡음제거 알고리즘은 다양한 형태의 잡음 밀도에 대해서 기존의 알고리즘에 비해 약 2dB 정도의 화질개선 효과를 얻었다.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제48권7호
• /
• pp.550-555
• /
• 1999

This paper deals with the effect of lightning impulse current on electrical characteristics of ZnO blocks used in distribution lightning arrester. The electrical characteristics of ZnO blocks are degraded by overtime impulse current, and the degraded ZnO block is brought to a thermal runaway and finally destroyed. It is therefore important to estimate the change of electrical characteristics of ZnO blocks. In this study, an impulse current generator which can produce 8/20$[\mus]$, 3[㎄] and 4/10$[\mus]$, 5[㎄] waveform is designed and fabricated to simulate the lightning impulse current of power systems. Total energy applied to the ZnO blocks at each time is 739[J] in 8/20$[\mus]$, and 523[J] in 4/10$[\mus]$, impulse current, respectively. From the experimental results, the 3rd harmonic of the leakage current increases continuously with the number of applied impulse current, but no significant changes in residual voltage and in reference voltage are observed until the ZnO block is destroyed. Also, it is confirmed that the main factor on degradation of ZnO blocks is rather the total energy applied to ZnO blocks than the peak value of the impulse current.

• 한국추진공학회:학술대회논문집
• /
• 한국추진공학회 2008년도 제31회 추계학술대회논문집
• /
• pp.145-148
• /
• 2008

현재 항우연에서 개발 중인 우주발사체 터보펌프에 사용되는 터빈은 단단 충동터빈을 적용하고 있다. 우주발사체의 안정성을 위해 팁 간극을 비교적 많이 허용하고 있는데, 효율적인 면에서는 반동터빈 보다 다소 뒤지지만, 높은 출력비를 가지는 충동터빈이 팁 간극이 커질 때 어떤 효율경향을 나타내는지 알아보는 일은 의미 있는 일이다. 실험은 아음속 조건에서 실험하였고, 팁 간극을 각각 코드기준 1%$\sim$20%일 경우 충동과 반동 각각의 경우에 대하여 하류 전압손실을 측정하였다. 측정결과 팁 간극이 10%보다 더 커지면, 충동터빈이 오히려 전압손실량이 반동터빈보다 더 작아진다. 이것은 팁 간극이 비교적 큰 조건에서 충동터빈이 반동터빈보다 효율이나 출력비 면에서 더 나은 성능을 나타냄을 의미한다.

• 패션비즈니스
• /
• 제19권6호
• /
• pp.1-13
• /
• 2015

This study aimed to determine the relationship between consumer regulatory focus and impulse buying of apparel products and the mediating effect of consumer fashion innovativeness. A large portion of consumer buying behavior is based on impulse. However, impulse buying is difficult to predict; moreover, factors that explain consumers' impulse buying tendencies are not yet fully identified. In this study, consumer regulatory focus was considered as a factor that explains consumers' impulse buying tendencies. The purpose of this study was to examine how fashion innovativeness and impulse buying tendencies differ, based on the consumer regulatory focus. A structural equation modeling was conducted to validate the research model. A questionnaire agency conducted online survey for 1 week and of the 400 copies distributed, total of 400 were collected. Promotion-focus and fashion innovativeness were positively correlated, which in turn had an effect on rational, emotional, and situational impulse buying. The promotion-focus had a negative effect on fashion innovation, but a positive effect on emotional impulse buying. On the other hand, prevention-focus had negative effect on emotional impulse buying, and situational impulse buying. Consumer regulatory focus and fashion innovativeness were useful predictors different consumer tendencies of impulse buying of apparel.

• 한국조리학회지
• /
• 제23권8호
• /
• pp.27-39
• /
• 2017

This study was to examine how consumption value of female consumers affects impulse consumption and purchase satisfaction when they buy bakery goods, present specific determinant factors that affect them, and identify its influencing factors. The survey was conducted with those who have bought bakery goods of female consumers in Seoul and Kyonggi area, using a convenience sampling method. After a total of 400 responses was collected, 366 responses were included for the multiple regression analyses in order to test the hypotheses. To summarize findings from this study, analysis of the first hypothesis showed that "emotional impulse buying," "stimulating impulse buying," "reminder impulse buying," and "situational impulse buying" among impulse buying factors in consumption value factors had positive effects. The second hypothesis analyzed that "emotional impulse buying," "stimulating impulse buying," and "situational impulse buying" gave positive impacts on "purchase satisfaction," while "reminder impulse buying" had no influence. Analysis of the third hypothesis demonstrated that "consumption value" had positive effects on "purchase satisfaction." These findings were significant to examine consumption value that show the consuming pattern of consumers, analyze influencing factors on impulse buying of female consumers, and further present marketing strategies used for advantageous tools with competing stores to bakery owners or marketers.

• 한국정밀공학회지
• /
• 제22권8호
• /
• pp.174-181
• /
• 2005

We analyzed the pressure, impulse on 24 sensors location under the foot using the Parolee system. Total 7 kinds of shoes, i.e. sport shoe, high heel shoes (5cm heel, 8cm heel, 13cm heel), platform shoe, inline skate, and heelys were evaluated for 20 normal subjects. Compared with those of sport shoe, greater pressure and impulse were shown on the 1 st phalange and the 1 st metatarsal head and greater impulse on the medial tarsal bone in high-heel shoes. Greater pressure and impulse were shown on medial metatarsal bone and the lateral tarsal bone in platform shoe. Greater impulse was shown on the medial tarsal bone in inline-skate. Heelys shoe showed smaller impulse on the central area of foot. The result of this study is expected to provide useful information about the relationship between the shoe type and the foot pathologies.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 춘계학술대회 논문집
• /
• pp.61-62
• /
• 2009

This paper describes the characteristics of lightning impulse current of ZnO block for transmission line arrester with external gap. The ageing parameters of lightning arresters ate impulse current, moisture ingress, temperature ageing and so on. Especially it is important to estimate the change of electrical characteristics by impulse current. Total energy applied to the ZnO arrester each time is $4/10{\mu}s$, 30kA and $2/20{\mu}s$, 10kA impulse current. Before and After the test, the residual voltage variation of varistors passed was below 5%. According to the test, it is thought that the ZnO arrester shows good stability with impulse current test.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
• /
• pp.458-459
• /
• 2007

This paper describes the characteristics of lightning impulse current of ZnO block for transmission line arrester with external gap. The ageing parameters of lightning arresters are impulse current, moisture ingress, temperature ageing and so on. Especially it is important to estimate the change of electrical characteristics by impulse current. Total energy applied to the ZnO arrester each time is $4/10{\mu}s$, 30kA and $2/20{\mu}s$, 10kA impulse current. Before and After the test, the residual voltage variation of varistors passed was below 5%. According to the test, it is thought that the ZnO arrester shows good stability with impulse current test.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제49권12호
• /
• pp.685-690
• /
• 2000

Multiple-lightning impulse currents are a general feature of the lightning ground f=flash. It is therefore necessary for lightning arresters used in power systems to be estimated by applying not only a single-lightning impulse current but also a multiple-lightning impulse currents. This paper presents the effects of multiple-lightning impulse currents on deterioration of ZnO arrester blocks. The multiple-lightning impulse generator which can produce quadruple 8/20$[\mus]$ 5[kA] with separation time of 30~120[ms] is designed and fabricated. The total energy applied to the arrester block at each impulse is about 1,200[J]. In experiment, various parameters such as leakage current component, reference voltage, and temperature are measured with the number of applied impulse current. Also, micro-structure changes of the ZnO blocks after applying the single and the multiple-lightning impulse currents of 200 times are compared. The experimental results indicate that the types of arrester blocks are more vulnerable to deterioration or damage by multiple-lightning impulse currents.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2002년도 학술대회지
• /
• pp.151-154
• /
• 2002

The twin impulse wave leads to very complicated flow fields, such as Mach stem, spherical waves, and vortex ring. The twin impulse wave discharged from the exits of the two tubes placed in parallel is investigated to understand detailed flow physics associated with the twin impulse wave, compared with those in a single impulse wave. In the current study, the merging phenomena and propagation characteristics of the impulse waves are investigated using a shock tube experiment and by numerical computations. The Harten-Yee's total variation diminishing (TVD) scheme is used to solve the unsteady, two-dimensional, compressible, Euler equations. The Mach number $M_{s}$, of incident shock wave is changed below 1.5 and the distance between two-parallel tubes, L/d, is changed from 1.2 to 4.0. In the shock tube experiment, the twin impulse waves are visualized by a Schlieren optical system for the purpose of validation of computational work. The results obtained show that on the symmetric axis between two parallel tubes, the peak pressure produced by the twin-impulse waves and its location strongly depend upon the distance between two parallel tubes, L/d and the incident shock Mach number, $M_{s}$. The predicted Schlieren images represent the measured twin-impulse wave with a good accuracy.