• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.168-173
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• 2007

인터넷 쇼핑몰들은 저조한 수익성에도 불구하고 소비자를 끌어들여 매출을 증대시키기 위해 다양한 유인가격전략을 사용하고 있으나 이러한 유인전략이 과연 효용성이 있는가 하는 문제를 주제로 6 개 인터넷 쇼핑몰의 실제 web logdata 를 활용하여 소비자의 실제 쇼핑행동을 파악하여 유인가격전략의 효용성을 실증적으로 측정하였다. 방대한 클릭데이터를 효과적으로 정리하는 방법을 제시했고 인터넷 쇼핑몰 업체의 유인가격전략 수립에 대한 가이드를 제시하였다.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.294-298
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• 2012

In sweet cherry (Prunus avium L.) growing there are several severe problem which have to be overcome to produce highly graded fruits because of fruit rots and fruit crackings, if there is frequent precipitation during immature fruit step and picking season. In order to reduce fungicide sprayings and produce qualified fruits in areas with rainy season like as South Korea, rain-sheltered growing is necessary absolutely. Sweet cherry blooms early to medium April in southern area of South Korea. If we depend on honeybees (Apis mellifera) distributed in natural ecosystem, it is not easy to get normal fruit-set every season because of low temperature around blooming time. And also bee keepers seldom sell honeybee hives as a pollinator during spring, instead they keep honeybee hives to get honey. Recently use of B. terrestris as a pollinator of cherry tomato, oriental pumpkin etc. grown in protected cultivation system increase abundantly. Therefore, in this study we studied B. terrestris as an alternate of honeybee to pollinate sweet cherry grown in rain shelter. In part of foraging activity B. terrestris shows staying on a cherry flower for about six second and visiting frequency of 11 flowers per minute. However A. mellifera stayed about 15 second on a flower and visited 4~5 flowers per minute. There were no significant difference in fruit-setting rate and fruit characteristics after using B. terrestris and A. mellifera as pollinators of sweet cherry. Consequently there is no negative effect when we use B. terrestris as an alternate pollinator of A. mellifera in sweet cherry cultivation under rain shelter.

• Journal of applied mathematics & informatics
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• v.25 no.1_2
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• pp.455-470
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• 2007

In phylogenetic tree construction the neighbor-joining algorithm is the most well known method which constructs a trivalent tree from a pairwise distance data measured by DNA sequences. The core part of the algorithm is its cherry picking criterion based on the tree structure of each quartet. We give a generalized version of the criterion based on the exact box model of quartets, known as the tight span of a metric. We also show by experiment why neighbor-joining and the quartet consistency count method give similar performance.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.1
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• pp.1-14
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• 2009

The efficiency of transportation requests fulfillment can be increased through extending the problem of vehicle routing and scheduling by the possibility of subcontracting a part of the requests to external carriers. This problem extension transforms the usual vehicle routing and scheduling problems to the more general integrated operational transportation problems. In this contribution, we analyze the motivation, the chances, the realization, and the challenges of the integrated operational planning and report on experiments for extending the plain Vehicle Routing Problem to a corresponding problem combining vehicle routing and request forwarding by means of different sub-contraction types. The extended problem is formalized as a mixed integer linear programming model and solved by a commercial mathematical programming solver. The computational results show tremendous costs savings even for small problem instances by allowing subcontracting. Additionally, the performed experiments for the operational transportation planning are used for an analysis of the decision on the optimal fleet size for own vehicles and regularly hired vehicles.

• Communications of the Korean Mathematical Society
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• v.25 no.1
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• pp.149-160
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• 2010

Among the distance based algorithms in phylogenetic tree reconstruction, the neighbor-joining algorithm has been a widely used and effective method. We propose a new algorithm which counts the number of consistent quartets for cherry picking with tie breaking. We show that the success rate of the new algorithm is almost equal to that of neighbor-joining. This gives an explanation of the qualitative nature of neighbor-joining and that of dissimilarity maps from DNA sequence data. Moreover, the new algorithm always reconstructs correct trees from quartet consistent dissimilarity maps.

• Management Science and Financial Engineering
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• v.11 no.3
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• pp.95-107
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• 2005

As online shopping malls have emerged as a substantial shopping channel, they have used various sales promotion strategies to acquire new customers. Most of these strategies have been applied by offline malls for years. One, loss-leader pricing, is a type of promotional pricing in which stores sell well known products below their marginal cost, in order to attract customers and induce them to purchase more goods through impulse buying. This strategy is based on the expectation that customers will factor transaction costs into their purchasing decisions. However, its application to online malls fails to recognize that transaction costs are lower online, and that customers will behave differently as a result. Our study predicts that loss-leader pricing will not work online because online malls entail lower searching and moving costs than offline malls The study examines the effectiveness of loss-leader pricing with empirical data from a survey as well as log data from a Korean online shopping mall. The results show that while loss-leader pricing does attract customers to online shopping malls, it encourages cherry-picking rather than impulse purchases of regular-price goods.