• Korean Journal of Mathematics
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• v.29 no.1
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• pp.105-120
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• 2021

In this paper, we extend some results related to the growth rates of entire functions by introducing the relative logarithmic order ����g(f) of a nonconstant entire function f with respect to another nonconstant entire function g. Next we investigate some theorems related the behavior of ����g(f). We also define the relative logarithmic proximate order of f with respect to g and give some theorems on it.

• Journal of the Ergonomics Society of Korea
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• v.15 no.2
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• pp.113-124
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• 1996

This study was initiated to suggest the optimal size intervals for mail-order clothing. The questionnaire survey was carried at 360 women and 50 men who purchased apparels by mail-order. The garment sizes providing at the various mail-order companies in Korea were compared. The garment sizes that consumers wanted to purchase were also investigated. The collected data were analyzed and optimal size intervals for mail-order clothing were decided by the loss function. The results are as follow. 1) The optimal size intervals were varied from 4cm to 7cm. The total expected loss of the apparel sizes suggested in this study was less than that of the current mail-order apparel sizes. When the number of sizes for mail-order clothing is increased, the expected loss was reduced considerably. 2) The mail-order clothing is made for consumers with average body size. 30 The number of garment sizes available by mail-order was under three. 4) Subjects tend to select larger size garments, when the right size garments are not available.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.1
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• pp.43-53
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• 1996

This study was initiated to investigate (1) the current sizing system for mail-order clothing, (2) consumers' preference for sizing systems, and (3) consumers' satisfaction with garment size. The apparel items and the sizes available at various mail-order companies in Korea were also reviewed. This investigation of consumers' preferences for various size description systems includes a survey of 410 men and women who had purchased garments by mail-order. The data were analyzed by Statistical Analysis System/pc. The major results are as follows; 1. The sizing system of mail-order clothing was different by garment items. The number of apparel sizes available for mail-order purchasing was three or less. The most mail∼order garments were labeled by the numerical size codes of body girth nleasurements or letter code (S, M, L). 2. The size description system most prefered by female subjects(N : 360) was the numerical size code of a body measurement(55.4%). The combination of bust-hips-height measurements size codes were prefered by 13.3% . The pictogram was least premiered by the subjects. 3. The apparel items that subjects wanted to buy using mail-order were underwear, home -weat and night-wear. The heavy users of mail-order purchasing, however, also wanted to purchase expensive garments requiring precise fit. The subjects aged from 20's to 80's wanted to purchase childern's wear by mail. 4. The desire for diversity of garment item and size of mail-order apparel was relatively high. The subjets also wanted to purchase special size garments by mail-order, e. g., garment sizes for full or tall figure.

• Proceedings of the Society of Korea Industrial and System Engineering Conference
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• 2002.05a
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• pp.349-357
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• 2002

This research is basically deals with an inventory distribution system with several regional sales branches. Under the continuous review policy, each sales branch places an order to its supplier whenever on hand plus on order inventory falls on the order point, and the order quantity is received after elapsing a certain lead time. This research first shows the method how to apply the product with low lever of demand into the continuous review policy. For the application, we use an order level as the maximum level of inventory during an order cycle. Also we analyze the lost sales case as a customer behavior. Further we use variable demands and variable lead times for more realistic situation. Based on the above circumstances, the research mainly discusses those methods to decide the optimal order level, order point, and order quantity for each sales branch which guarantees the system wide goal level of service, while keeping the minimum level of the system wide total inventory.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.25 no.3
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• pp.78-84
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• 2002

This research is basically deals with an inventory distribution system with several regional sides branches. Under the continuous review policy, each sales branch places an order to its supplier whenever on hand plus on order inventory falls on the order point, and the order quantity is received after elapsing a certain lead time. This research first shows the method how to apply the product with low lever of demand into the continuous review policy. For the application, we use an order level as the maximum level of inventory during an order cycle. Also we analyze the lost sales case as a customer behavior. Further we use variable demands and variable lead times for more realistic situation. Based on the above circumstances, the research mainly discusses those methods to decide the optimal order level, order point, and order quantity for each sales branch which guarantees the system wide goal level of service, while keeping the minimum level of the system wide total inventory.

• Korean Management Science Review
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• v.21 no.3
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• pp.101-113
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• 2004

In the rapidly propagating Internet based electronic transaction environment. the importance of real time order confirmation has been more emphasized, In this paper, using data mining techniques, we develop intelligent operations decision model to allow real time order confirmation at the time the customer places an order with required delivery terms. Among various operation plannings used for order fulfillment. mill routing is the first interface decision point to link the order receiving at the marketing with the production planning for order fulfillment. Though linear programming based mathematical optimization techniques are mostly used for mill routing problems, some early orders should wait until sufficient orders are gathered for optimization. And that could effect longer order fulfillment lead-time, and prevent instant order confirmation of delivery terms. To cope with this problem, we provide the intelligent decision model to allow instant order based mill routing decisions. Data mining techniques of decision trees and neural networks. which are more popular in marketing and financial applications, are used to develop the model. Through diverse computational trials with the industrial data from the steel company. we have reported that the performance of the proposed approach is effective compared to the present heuristic only mill routing results. Various issues of data mining techniques application to the mill routing problems having linear programming characteristics are also discussed.

• Korean Journal of Mathematics
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• v.17 no.4
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• pp.361-374
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• 2009

We characterize a fuzzy partial order relation using its level set, find sufficient conditions for the image of a fuzzy partial order relation to be a fuzzy partial order relation, and find sufficient conditions for the inverse image of a fuzzy partial order relation to be a fuzzy partial order relation. Also we define a fuzzy lattice as fuzzy relations, characterize a fuzzy lattice using its level set, show that a fuzzy totally ordered set is a distributive fuzzy lattice, and show that the direct product of two fuzzy lattices is a fuzzy lattice.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.61-62
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• 2003

In this paper, the new higher order wall boundary conditions are proposed for solving the incompressible flows. The square driven cavity flows are simulated by using the variable order method of lines with the present wall boundary conditions. The variable order method of lines is constructed by the spatial discretization, i.e., the variable order proper convective scheme for convective terms and the modified differential quadrature method for diffusive terms, and time integration. The 2nd, 4th, and 6th order solutions are presented and these results show this higher order boundary conditions are very promising for the incompressible flow simulations.

• Journal of Korean Institute of Industrial Engineers
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• v.25 no.2
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• pp.192-203
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• 1999

This paper deals with the order release problem for minimizing weighted earliness and tardiness as well as Work In Process (WIP) in dynamic job shop environments. A newly designed hierarchical order release mechanism is developed for efficient real-time control of the earliness/tardiness and WIP. The hierarchical order release mechanism consists of the order release plan and the order release control which is composed of two procedures. The experimental results show that the proposed order release mechanism is superior to other four order release mechanisms under overall simulation conditions of utilization rate, due-date allowances, and earliness/tardiness cost structures. In addition, the difference of total cost among the four dispatching rules is much more reduced in the proposed order release mechanism than in other release mechanisms.

• Journal of Navigation and Port Research
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• v.33 no.7
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• pp.477-482
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• 2009

In this paper the order picking problem in warehouses is considered, a topic which has received considerable attention from the international academic body in recent years. The order picking problem deals with the retrieval of order items from prespecified locations in the warehouse, and its objective is usually the minimization of travel time or travel distance. Hence, a well-thought order picking policy in combination with an appropriate storage policy will enhance warehouse efficiency and reduce operational costs. This paper starts with a literature overview summarizing approaches to routing order pickers, assigning stock-keeping units to pick locations and designing warehouse layouts. Since the layout design might affect both storage and routing policies, the three factors are interdependent with respect to order picking performance. To test these interdependencies, a simulation experiment was set up, involving two types of warehouse layout, four types of storage policy, five well-known heuristics and five sizes of order picking list. Our results illustrate that from the point of view of order picking distance minimization it is recommended to equip the warehouse with a third cross aisle, although this comes at the cost of a certain space loss. Additionally, we propose a set of most appropriate matches between order picking heuristics and storage policies. Finally, we give some directions for further research and recommend an integrated approach involving all factors that affect warehouse efficiency.