• Industrial Engineering and Management Systems
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• 제12권2호
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• pp.95-102
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• 2013

It is difficult to determine an appropriate discount price for daily perishable products to increase profit from a long-term standpoint. Even if the discount pricing is efficient to increase profit of the day, consumers memorize the sales price and they might hesitate to purchase the product at a regular price the following day. The authors discussed the inventory clearance pricing for a single period in our previous study by constructing a mathematical model to derive an optimal sales price to maximize the expected profit by considering the reference price effect of demand. This paper extends the discussion to handle the discount pricing for multiple periods. A mathematical analysis is first conducted to reveal the properties on an objective function, which is the present value of total expected profits for multiple periods. An algorithm is then proposed to derive an optimal price for asymmetric consumers. Numerical experiments investigate the characteristics of the objective function and optimal pricings.

• 가정과삶의질연구
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• 제27권6호
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• pp.229-242
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• 2009

This study investigates how bioecological variables affect the child's multiple intelligence through independent and interactional ways. The subjects of this study were 147 pairs of 5-year-old children and their mothers, and the Project Spectrum was employed to measure multiple intelligences. Each mothers was asked to answer a questionnaire on her child's temperament, her maternal parenting style, 'goodness of fit' and 'the fit of child's intelligence'. Data were analyzed using a factor analysis and a hierarchical multiple regression with SPSS WIN 15.0. The main findings were as followings; First, 'the goodness of fit' to the child's temperament moderated the effect of a maternal parenting style that would foster child's dependency on the mathematical intelligence through interaction. 'The fit of child's intelligence' also moderated the effect of maternal positive parenting style to the child's mathematical intelligence. Second, in language intelligence, girls were more verbally intelligent than boys. In that regard, because the sex variable entails a combination of both inherent attribute and social-cultural effects, that result can be interpreted as an interaction between the individual and the environment. Lastly, a maternal parenting style that would foster child's dependency moderated the effect of the child's regular temperament on interpersonal intelligence. This means that the child's regular temperament can be a protective factor for the negative effect of a maternal parenting style that would foster child's dependency This study suggests that interactional factors such as 'goodness of fit' should be considered in studies involving children.

• 물과 미래
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• 제29권3호
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• pp.143-152
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• 1996

도시하천의 복개구간내 흐름의 수리는 복개슬라브를 지지하는 말뚝군 주위에 발생하는 과류의 중첩 및 간섭효과 때문에 대단히 복잡하다. 본 연구에서는 말뚝군의 여러 가지 배치에 따른 배수위 상승효과를 정량적으로 산정하기 위한 방법을 제안하기 위해 광범위한 실험적 연구를 수행하였다. 배수위 상승을 지배하는 인자로는 말뚝군으로 인한 흐름단면의 축소율과 흐름의 Froude 수, 흐름 방향으로의 말뚝군 간격, 복개구간의 총길이 등으로 밝혀졌다. 흐름방향에 직각인 방향으로 교각을 설치한 경우 단면 축소율과 흐름의 Froude수가 배수위 상승에 미치는 영향을 분석하였으며 배수위 상승량의 산정을 위한 다중회귀분석식을 도출하였다. 흐름의 횡방향 및 종방항으로 배치시킨 말뚝군이 배수위 상승에 미치는 영향도 단면 축소율, 흐름의 Froude 수, 흐름방향의 말뚝간 간격 및 복개구간의 총길이 등의 항으로 분석하였으며, 실험자료의 다중회귀분석에 의해 이들 영향인자를 사용하여 배수위 상승률을 산정할 수 있는 경험식을 도출, 제안하였다.

• 한국해양공학회지
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• 제6권1호
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• pp.96-104
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• 1992

Aircraft structures and engineering structures are always subject to variable amplitude loads. Variable amplitude loads include some kind of loading history; for example, constant amplitude load, single peak overload and block overload etc. Crack growth under variable amplitude loading exhibits retardation effect. In this study, the 4 point bending fatigue test was performed by hydrolic servo fatigue testing machine on 7075-T6 Al-alloy. The retardation effect of overload ratio and numbers of overload cycle was quantitatively studied. 1) Change of retardation effect against increment of overload ratio is more evident when the multiple overload is applied than single overload is done. 2) The number of overload cycle is very important factor about the crack growth retardation effect when the overload ratio is more than 1.75; that is not when the overload ratio is less than 1.75. 3) Overload affected zone size increased gradually by increment of crack growth retardation effect. 4) Crack driving force is more greatly reduced when the crack tip branched off two direction than it sloped to one direction.

• 한국의류학회지
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• 제30권2호
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• pp.266-274
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• 2006

This study aims to examine the effect of mass media on fashion leadership of make-up and fashion products. The subjects of the study were 168 women consumers who lived in Seoul. Data were collected during September in 2003. Statistical analyses used in this study were frequency, Cronbach's $\alpha$, ANOVA, Duncan test, t-test, and multiple regression. The results of this study were as follows; 1. As a result of multiple regression for the effect of mass media on fashion leadership of make-up, there was a significant effect of movies on fashion leadership of make-up. 2. As a result of multiple regression for the effect of mass media on fashion leadership of fashion product, there were significant effects of magazines, internet, and movies on fashion leadership of fashion product. 3. In regard to the effects of consumer characteristics on fashion leadership, there were significant effects of consumer characteristics on fashion leadership of make-up and fashion product.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.257-262
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• 2004

A series of preliminary model tests are performed to find out the wave attenuating effect of the pneumatic breakwater of environment friendly type, which is a bubble screen generated by releasing compressed air from a submerged multiple parallel manifold Rising bubbles induce vertical current, which produces horizontal currents flowing away from the bubble-screen area in both directions. Near bottom, the corresponding currents flow toward the bubble screen, thus completing the circulation pattern. The surface current moving against the direction of wave propagation causes some attenuation of the waves. It becomes more effective as the relative depth (d/ L) increases (short-period waves in deep water). With the same air-discharge, the multiple parallel manifold can be more effective for the attenuation of longer waves through optimum arrangement of manifold number. installation depth, manifold gap, etc. The pneumatic breakwater will give a wide utilization as a device for protecting harbor facilities and as a simple, mobile breakwater.

• 한국수소및신에너지학회논문집
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• 제20권4호
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• pp.265-273
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• 2009

Proton Exchange Membrane Fuel Cell (PEMFC) has low operating temperature and high efficiency. And PEMFC consists of many components as bipolar plate, gas diffusion layer, membrane etc.. Flow-field in bipolar plate roles path for transporting reactants to membrane. Therefore a design of flow-field has an effect on PEMFC's performance. In this study, Computational Fluid Dynamics (CFD) simulations were performed for comparing mixed multiple serpentine (MMS) flow-field and multiple serpentine (MS) flow-field. And we studied an effect according to change mixing region design in MMS flow-field. Finally the applicability of results is verified by performing CFD simulation about fixed MMS flow-field which is combined good designs.

• 한국자동차공학회논문집
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• 제15권4호
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• pp.76-82
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• 2007

This paper described the effect of the multiple injections on the stability of combustion and emission characteristics in a direct injection diesel engine at various operating conditions. In order to investigate the influence of multiple injections in a diesel engine, the fuel injection timing was varied one main injection and two pilot injections at various conditions. The experimental apparatus consisted of DI diesel engine with four cylinders, EC dynamometer, multi-stage injection control system, and exhaust emissions analyzer. The combustion and emission characteristics were analyzed for the main, pilot-main injection, pilot-pilot-main injection strategies. It is revealed that the combustion pressure was smoothly near the top dead center and the coefficient of variations is reduced due to the effect of pilot injection. Also, $NO_x$ emissions are dramatically decreased with pilot injection because the decrease of rate of heat release. However, the soot is increased at early pilot injection and main injection.

• 한국시뮬레이션학회논문지
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• 제13권1호
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• pp.41-50
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• 2004

The purpose of this paper is to analyse the manager's policy to maximize the profit in a multiple-server queueing facility with a limited queue capacity. We assume that the level of advertizing effects on the arrival rate of customers to the facility. The model without ‘word of mouth effect’ is assumed that the arrival rate is independent on the qualify of service level. We estimate the service quality by the balking rate of customers from system. We extend this to the model with ‘word of mouth effect’. To achieve the maximum profit, the most important factor is the considerably high utilization of facility for both models. Given service rate, we should maintain an effective arrival rate to some extent. To this end, among the available options, an increase of advertizing effort is more desirable than reducing the fee if the service value of customers remains unchanged. We also investigate whether the variability of service time has a significant impact on determining the optimal policy. The cost of service variability is not so expensive as that in a single server model due to the reduced variability of service times in a multiple-server model.

• 한국국방경영분석학회지
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• 제6권2호
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• pp.69-88
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• 1980

A stochastic fundamental duel with continous interfiring times is considered for including the kill effect of multiple hits and fixed duel time. Two alternatives, 'vital hit' and 'damage coefficient' approaches, are developed. Since a large quantity of ammunition is consumed when a sure kill is obtained through repetitive multiple hits, limitation of initial ammunition supply is included in the stochastic duel models with multiple hits and fixed duel time. General solutions are obtained and examples with negative exponential interfiring times and geometric ammunition supply are given.