• Journal of applied mathematics & informatics
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• 제29권5_6호
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• pp.1381-1393
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• 2011

In this paper, we consider two-species periodic Gilpin-Ayala competition system with delay and impulsive effect. By using some analysis methods, sufficient conditions for the permanence of the system are derived. Further, we give the conditions of the existence and global asymptotic stable of positive periodic solution.

• 대한가정학회지
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• 제48권8호
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• pp.99-111
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• 2010

The purpose of this study was to identify the factors, which influence impulsive buying at duty-free shops. This involved an investigation into the effects of demographic characteristics, the types of purchased items, and the situational and emotional factors affecting impulsive purchasing behaviour in consumers, who had bought items from duty free shops in the past three years. The findings are as follows. Firstly, while beverage and cosmetic items were found to encourage impulse buying, in general demographic variables and type of product had only a slight influence. Secondly, the situational factors of price benefits, overseas luxury branding, and ease of access in the duty free shopping area all had a definite positive influence. Thirdly, with regard to emotional factors, positive emotion was found to have strong augmenting effect on impulsive purchasing. The findings can be used in the development of educational materials to prevent impulsive purchasing and promote sensible consumer behaviour.

• 가정과삶의질연구
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• 제19권5호
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• pp.189-202
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• 2001

The purpose of this study was to investigate the effects of perceived parents-adolescent communication style on adoescent’s self-efficacy. The subjexts of this study were 625 students selected at random from first and second grade of high school in Daegu. A questionnaire was used as survey method. Factor analysis, MANOVA and cluster analysis for data analysis and Scheffe test for post-hoc analysis were employed. The man findings were as follows: Firs, there were significant differences in the degree of adolescent’s self-efficacy according to perceive father-adolescent communication style. In case that adolescents perceived their father’s communication style as reasonable, the degree of self-control, self-confidence and attribution were higher than those of other cases such as non-interferential or impulsive communication style. The adolescents who perceived the father’s communication style as reasonable showed higher preference of difficult task than those who perceived it as non-interferential style. The adolescents who perceived father’s communication style as reasonable and non-interferential showed higher attribution than those who perceived it as impulsive style. Second, there were significant differences in the degree of adolescent’s self-efficacy according to perceived mother-adolescent communication style. In case that adolescents perceived their mother’s communication style as reasonable, the degree of self-control was higher than that of other cases such as non-interferential and impulsive communication style. The adolescents who perceived their mother’s communication style as reasonable showed higher self-confidence than those who perceived as impulsive style.

• 한국해안·해양공학회논문집
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• 제27권3호
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• pp.175-181
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• 2015

본 연구에서는 2차원 수리실험을 통해 충격파 및 비충격파 조건에서의 직립식구조물의 월파량 산정식을 제안하였으며, 연구결과는 EurOtop(2007)의 결과와 비교하였다. 특히, 최근의 월파량 산정기법의 연구동향을 고려하여 도표형태가 아닌 함수형태로 월파량 산정식을 제안하였다. 상대여유고와 무차원 월파량의 관계를 비충격파 조건은 지수함수, 충격파 조건은 거듭제곱 함수 형태로 제시하였다. 또한 경사형 상치콘크리트가 월파량에 미치는 영향계수를 제시하였다. 경사형 상치콘크리트의 설치위치가 월파량에 미치는 영향을 검토한 결과에 의하면 설치위치에 따른 차이는 크지 않은 것으로 나타났다.

• 한국자동차공학회논문집
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• 제14권4호
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• pp.139-148
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• 2006

Valve train is one of the important noise sources in idling engines. Valve train noise comes mostly from two different impacts. One is the impact between cam and tappet at the beginning of the valve open period, which is an important source of impulsive noise of valve trains. The other is the impact between valve and valve seat at the closing of the valve open period. In case of mechanical lash adjusters, it is very difficult to control the initial impact. In this paper, we designed various types of cam profiles, especially in the opening ramp design, and investigated the effect of cam profiles on the magnitude of the initial impact. The effects that some cam design parameters have on the impulsive noise are also observed.

• 소음진동
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• 제11권2호
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• pp.241-248
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• 2001

The present paper describes experimental and computational work to augment the magnitude of the impulsive wave. An experiment was performed using a simple shock tube with an open end and numerical calculations were carried out to solve the unsteady, axisymmetric, inviscid, compressible governing equations. The control strategy applied was to alter the exit geometry of a straight tube to a sudden enlargement tube and a flare tube. The effects of the configurations of the tube exit on the magnitude of the impulsive wave were investigated over the range of the weak shock Mach number from 1.01 to 1.10. The results obtained were compared to those of the straight tube tests. The numerical result predicted the magnitude of the experimented impulsive waves with a good accuracy. The present passive control technique enabled the magnitude of the impulsive wave to augment by about 23 percent, compared to that of the straight tube of no control.

• International Journal of Human Ecology
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• 제13권1호
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• pp.159-169
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• 2012

This study examined how financial education, impulsive buying, and socio-demographic factors affect saving behavior of 500 Korean college students. The descriptive results show that students who received financial education reported more positive saving behavior compared to students who did not receive financial education in school. The OLS results indicate that all else being equal, students with financial education reported more positive saving behavior than those without financial education. As predictors of saving behavior among Korean college students, the OLS results also reveal that impulsive buying, gender, and age were statistically significant. This study concludes that receiving financial education early, such as in elementary school, plays an important role in determining the saving behavior of Korean college students.

• 한국통신학회논문지
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• 제23권4호
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• pp.950-956
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• 1998

In this paper, we investigate the effects of impulsive noise on the DS/SSMA system using TCM. We obtain the bound on the probability of bit error of the system, considering bothing impulsive noise and Rician fading, which are unavoidable in mobile communication environments. it turns out that we can achieve some coding gain by using TCM under impulsive noise environment. It is observed that the bit error probability is dominated by the background noise variance when the SNR is low and by the tail noise variance when the SNR is high.

• Human Ecology Research
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• 제54권4호
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• pp.385-395
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• 2016

This study examines the effects of consumer socialization on Korean adolescent impulsive buying behavior. The current study used the third and sixth waves from the Korean Education and Employment Panel (KEEP) survey that has been administered by the Korea Research Institute for Vocational Education and Training since 2004. The subjects were high school juniors and university sophomores in 2006 and 2009, respectively. The final sample for panel regression analysis included 1,718 individuals. Two major agents of socialization (school and parents) were utilized in our model. Parent financial behavior (if the parents had savings) and the effectiveness/helpfulness of economics education in middle or high school were included in our estimation model. Two categories were included as individual factors: (1) psychological aspects and personal traits covering variables such as stress from self-image, academic stress, self-regulation, and a tendency of risky behavior and (2) financial behavior and attitudes, which include work experience, amount of money in hand, shopping habits, and if parental financial support is expected after high school graduation. The results from a random effects model revealed that the effects of consumer socialization through school was marginally significant, while through parents was not. Stress from self-image and the level of self-regulation were found to be significant. Neither risky behavior nor academic stress were a significant factor for impulsive buying behavior. The amount of money available in hand and shopping habits showed a significant influence. Implications for educators, parents and policy makers are identified.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제14권4호
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• pp.225-247
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• 2010

In this paper, we establish a two-competitive-prey and one-predator Holling type II system by introducing a proportional periodic impulsive harvesting for all species and a constant periodic releasing, or immigrating, for the predator at different fixed time. We show the boundedness of the system and find conditions for the local and global stabilities of two-prey-free periodic solutions by using Floquet theory for the impulsive differential equation, small amplitude perturbation skills and comparison techniques. Also, we prove that the system is permanent under some conditions and give sufficient conditions under which one of the two preys is extinct and the remaining two species are permanent. In addition, we take account of the system with seasonality as a periodic forcing term in the intrinsic growth rate of prey population and then find conditions for the stability of the two-prey-free periodic solutions and for the permanence of this system. We discuss the complex dynamical aspects of these systems via bifurcation diagrams.