• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.2
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• pp.35-54
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• 2009

The recent economic crisis not only reduces the profit of department stores but also incurs the significance losses caused by the increasing late-payment rate of credit cards. Under this pressure, the scope of credit prediction needs to be broadened from the simple prediction of whether this customer has a good credit or not to the accurate prediction of how much profit can be gained from this customer. This study classifies the delinquent customers of credit card in a Korean department store into homogeneous clusters. Using this information, this study analyzes the repayment patterns for each cluster and develops the credit prediction system to manage the delinquent customers. The model presented by this study uses Kohonen network, which is one of artificial neural networks of data mining technique, to cluster the credit delinquent customers into clusters. Cox proportional hazard model is also used, which is one of survival analysis used in medical statistics, to analyze the repayment patterns of the delinquent customers in each cluster. The presented model estimates the repayment period of delinquent customers for each cluster and introduces the influencing variables on the repayment pattern prediction. Although there are some differences among clusters, the variables about the purchasing frequency in a month and the average number of installment repayment are the most predictive variables for the repayment pattern. The accuracy of the presented system leaches 97.5%.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.405-408
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• 2004

This paper describes an architecture information management system using XML. The purpose of the system is to manage the information stored in standard format, XML, that has many valuable properties. The proposed architecture information consists of project information, drawing information, and material information. Each information is expressed using XML and for each information, XML schema is presented in this paper. In this system, detail information of materials that exists on the supplier's homepage can be displayed when the user of the system wants to check the detail information. Also, drawings stored in STEP data can be browsed in this system. The reports of each information are prepared using XSL. The proposed system shows that XML can be used for a format to store architecture information and various functions can be implemented based on XML related standards.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.1
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• pp.35-55
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• 2015

In this research, we analyze the effects of price discounts and scarcity message (both quantity limitation message and time limitation message) on the purchase intention in the smart-phone environment. The purchase intention becomes higher at high discount rate and with scarcity message (both quantity limitation message and time limitation message). We also analyze the moderating effects of consumer's shopping value and distance between the consumer and the store on the effects of price discounts and scarcity message (both quantity limitation message and time limitation message) on the purchase intention. On average, the effects of price discount, time limitation message and quantity limitation message on the purchase intention become the highest levels for consumers pursuing hedonic shopping value. The effects of price discount, time limitation message and quantity limitation message on the purchase intention become higher when they are offered within a short distance between the coupon provider and the target customer.

• Journal of the Korean Operations Research and Management Science Society
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• v.39 no.3
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• pp.63-82
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• 2014

The main objective of this research is to investigate whether the RFM (recency-frequency-monetary value) information of a customer's redemption behavior of loyalty points can improve the prediction of future value of the customer. The conventional measurement of customer value has been primarily based on purchase transactions behavior although a customer's future behavior can be also influenced by other interactions between the customer and the firm such as redemption of rewards in a loyalty program. We theorize why a customer's redemption behavior can influence her future purchases and thereby the customer's total value based on operant learning theory, goal gradient hypothesis, and lock-in effect. Using a dataset from a major book store in Korea spanning three years between 2008 and 2010, we analyze both purchase transactions and redemption records of over 10,000 customers. The results show that the redemption-based RFM information does improve the prediction accuracy of the customer's future purchases. Based on this result, we also propose an improved estimate of customer lifetime value (CLV) by combining purchase transactions and loyalty points redemption data. Managerial implications will be also discussed for firms managing loyalty programs to maximize the total value customers.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.2
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• pp.275-282
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• 2015

Since a NAND-flash memory is able to keep data during electricity-off and has small cost to store data per bytes, it is widely used on hand-held devices. It is necessary to use an index in order to process mass data effectively on the flash memory. However, since the flash memory requires high cost for a write operation and does not support an overwrite operation, it is possible to reduce the performance of the index when the disk based index is exploited. In this paper, we implement the fixed grid file index and evaluate the performance of the index on various conditions. To do this, we measure the average processing time by the ratio of query operations and update operations. We also the compare the processing times of the flash memory with those of the magnetic disk.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.3
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• pp.134-142
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• 2002

Quadtree, which is a hierarchical data structure, is a very important data structure to represent binary images. The linear quadtree representation as a way to store a quadtree is efficient to save space compared with other representations. Therefore, it has been widely studied to develop efficient algorithms to execute operations related with quadtrees. The window operation is one of important geometry operations in image processing, which extracts a sub-image indicated by a window in the image. In this paper, we present an algorithm to perform the window operation of binary images represented by quadtrees, using three-dimensional $n{\times}n{\times}n$ processors on RMESH(Reconfigurable MESH). This algorithm has constant-time complexity by using efficient basic operations to route the locational codes of quardtree on the hierarchical structure of $n{\times}n{\times}n$ RMESH.

• The KIPS Transactions:PartA
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• v.14A no.3 s.107
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• pp.151-158
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• 2007

Quadtree, which is a hierarchical data structure, is a very important data structure to represent images. The linear quadtree representation as a way to store a quadtree is efficient to save space compared with other representations. Therefore, it has been widely studied to develop efficient algorithms to execute operations related with quadtrees. The computation of block location is one of important geometry operations in image processing, which extracts a component completely including a given block. In this paper, we present a constant time algorithm to compute the block location of images represented by quadtrees, using three-dimensional $n\times n\times n$ processors on RMESH(Reconfigurable MESH). This algorithm has constant-time complexity by using efficient basic operations to deal with the locational codes of quardtree on the hierarchical structure of $n\times n\times n$ RMESH.

• The KIPS Transactions:PartA
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• v.10A no.3
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• pp.207-214
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• 2003

Quadtree, which is a hierarchical data structure, is a very important data structure to represent binary images. The linear quadtree representation as a way to store a quadtree is efficient to save space compared with other representations. Therefore, it has been widely studied to develop efficient algorithms to execute operations related with quadtrees. The linear translation is one of important operations in image processing, which moves the image by a given distance. In this paper, we present an algorithm to perform the linear translation of binary images represented by quadtrees, using three-dimensional $n{\times}n{\times}n$ processors on RMESH (Reconfigurable MESH). This algorithm has constant-time complexity by using efficient basic operations to route the locational codes of quardtree on the hierarchical structure of n${\times}$n${\times}$n RMESH.

• The Journal of Bigdata
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• v.5 no.2
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• pp.1-15
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• 2020

The duty-free industry before COVID-19 has continuously grown since 2000, along with the increase of demand in tourism industry. To cope with the increased demand, the duty free companies have kept the strategies which focused on the sales volume. Therefore, they have developed the ways to increase the volume and capacity, not the efficient operations. In the most of previous research, however, authors have proposed the better strategies for marketing and supporting policies. It is very hard to find the previous research which dealt with the operations like logistics and inventory management. Therefore, in this study, it has been predicted the future demand of frequently purchased items in airport duty free shops based on the estimated number of departing passengers by the linear regression, which concluded with the appropriate inventory level. In addition, it has been analyzed the expected effects by introducing the inventory management policy considering the cost and efficiency of operations. Based on the results of this study, it may be possible to reduce total cost and improve productivity by predicting the excessive inventory problems at duty-free shops and improving cycles of supplying items.

• Proceedings of the IEEK Conference
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• 2002.07a
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• pp.458-461
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• 2002

The consumer in the 21$\^$st/ century e-business era is developing a taste fur greater professionalism diversity, internationalism and large-scale integration of his or her demands. With these changes in the consumers preferences in mind, e-businesses need to develop a real time track and trace system to accommodate their logistical and consumer service operations. This research paper discusses the development of a object-oriented logistics tracking database system and a web service tracking component necessary to efficiently store and manage the movements of postal goods and provide real time information on logistics trading.