• The Journal of the Korea Contents Association
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• v.7 no.8
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• pp.13-20
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• 2007

Decision tree is one of the most useful analysis methods for various data mining functions, including prediction, classification, etc, from massive data. Decision tree grows by splitting nodes, during which the purity increases. It is needed to stop splitting nodes when the purity does not increase effectively or new leaves does not contain meaningful number of records. Pruning is done if a branch does not show certain level of performance. By pruning, the structure of decision tree is changed and it is implied that the previous splitting of the parent node was not effective. It is also implied that the splitting of the ancestor nodes were not effective and the choices of attributes and criteria in splitting them were not successful. It should be noticed that new attributes or criteria might be selected to split such nodes for better tries. In this paper, we suggest a procedure to modify decision tree by Fuzzy theory and splitting as an integrated approach.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.11
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• pp.2367-2372
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• 2009

Recently, Many studies have been progressing to path-finding adapted dynamic information on the Terminal Based Navigation System(TBNS). The algorithms proposed are based on $A^*$ algorithm. Path-finding algorithms which use heuristic function may occur a problem of the increase of exploring cost. Path-finding with an abstract graph which expresses real road network as a simple graph is proposed for reducing dependency of heuristic and exploring cost. In this paper, two abstract graph that are different method of construction, Homogeneous Node merging($AG^H$) and Connected Node Merging($AG^C$), are implemented. In result of evaluation of performance, $AG^C$ has better performance than $AG^H$ at construction cost and the number of node access but $AG^C$ has worse performance than AGH at exploring cost.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.245-248
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• 2009

Recently, Many studies have been progressing to path-finding with dynamic information on the Terminal Based Navigation System(TBNS). However, the most of existing algorithms are based on $A{\ast}$ algorithm. Path-finding algorithms which use heuristic function may occur a problem of the increase of exploring cost in case of that there is no way determined by heuristic function or there are 2 way more which have almost same cost. In this paper, two abstract graph(AG) that are different method of construction, Homogeneous Node merging($AG^H$) and Connected Node Merging($AG^C$), are implemented. The abstract graph is a simple graph of real road network. The method of using the abstract graph is proposed for reducing dependency of heuristic and exploring cost. In result of evaluation of performance, $AG^C$ has better performance than $AG^H$ at construction cost but $AG^C$ has worse performance than $AG^H$ exploring cost.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.2
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• pp.19-29
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• 2015

The purpose of this study is to suggest the grid search method for selecting an optimal decision tree model. It chooses optimal values for the maximum depth of tree and the minimum number of observations that must exist in a node in order for a split to be attempted. Therefore, the grid search method guarantees building a decision tree model that shows more precise and stable classifying performance. Through empirical analysis using data of job satisfaction of workplace reserve force commanders, we show that the grid search method helps us generate an optimal decision tree model that gives us hints for the improvement direction of labor conditions of Korean workplace reserve force commanders.

• ETRI Journal
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• v.27 no.6
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• pp.733-746
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• 2005

In the context of multi-protocol label switching (MPLS) traffic engineering, this paper proposes a scalable constraintbased shortest path first (CSPF) routing algorithm with multiple QoS metrics. This algorithm, called the multiple constraint-based shortest path first (M_CSPF) algorithm, provides an optimal route for setting up a label switched path (LSP) that meets bandwidth and end-to-end delay constraints. In order to maximize the LSP accommodation probability, we propose a link weight computation algorithm to assign the link weight while taking into account the future traffic load and link interference and adopting the concept of a critical link from the minimum interference routing algorithm. In addition, we propose a bounded order assignment algorithm (BOAA) that assigns the appropriate order to the node and link, taking into account the delay constraint and hop count. In particular, BOAA is designed to achieve fast LSP route computation by pruning any portion of the network topology that exceeds the end-to-end delay constraint in the process of traversing the network topology. To clarify the M_CSPF and the existing CSPF routing algorithms, this paper evaluates them from the perspectives of network resource utilization efficiency, end-to-end quality, LSP rejection probability, and LSP route computation performance under various network topologies and conditions.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.382-386
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• 2011

This study aims to identify the cause for low appearance of flowers in 'Heukgoosul' grapevines, and determine basic characteristics of the axillary buds and types of necrosis in order to find out their influence on necrosis. As for $1^{st}$ to $4^{th}$ node, the closer buds were located to cane, the smaller the size of buds became. However, there was no difference in the size of an axillary bud in the upper part of the shoot above the 4th node. The bud necrosis occurrence in the $1^{st}$ node was the highest with 32% while buds in $4^{th}$ to $10^{th}$ node were normal with 84~96%. The size of buds in July was the largest with 6.40 mm, while buds showed no difference from August to October. The bud necrosis and main bud necrosis occurred most frequently in October, however accessory bud necrosis took place from July demonstrating no difference since then. The analysis on the relationship between shoot vigor and necrosis of axillary buds showed that the shoot diameter and internodes' length have no co-relationship with axillary bud necrosis, but there were negative relationship between the size of buds and necrosis occurrence, which was the most related to accessory bud necrosis. Therefore, despite the low occurrence of bud necrosis and healthy buds in 'Heukgoosul' grapevines, there was little appearance of flowers in the grapevines, which was attributable to the necrosis in the first bud. In conclusion, the research suggests spur pruning with three nodes kept intact yield.

• Journal of KIISE:Databases
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• v.36 no.5
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• pp.341-351
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• 2009

Recently high utility pattern (HUP) mining is one of the most important research issuer in data mining since it can consider the different weight Haloes of items. However, existing mining algorithms suffer from the performance degradation because it cannot easily apply Apriori-principle for pattern mining. In this paper, we introduce new high utility pattern mining approach by using a prefix-tree as in FP-Growth algorithm. Our approach stores the weight value of each item into a node and utilizes them for pruning unnecessary patterns. We compare the performance characteristics of three different prefix-tree structures. By thorough experimentation, we also prove that our approach can give performance improvement to a degree.

• Journal of Korea Spatial Information System Society
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• v.11 no.4
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• pp.39-46
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• 2009

Generally, Path-finding algorithms which use heuristic function may occur a problem of the increase of exploring cost in case of that there is no way determined by heuristic function or there are 2 way more which have almost same cost. In this paper, we propose an abstract graph for path-finding with dynamic information. The abstract graph is a simple graph as real road network is abstracted. The abstract graph is created by fixed-size cells and real road network. Path-finding with the abstract graph is composed of two step searching, path-finding on the abstract graph and on the real road network. We performed path-finding algorithm with the abstract graph against A* algorithm based on fixed-size cells on road network that consists of 106,254 edges. In result of evaluation of performance, cost of exploring in path-finding with the abstract graph is about 3~30% less than A* algorithm based on fixed-size cells. Quality of path in path-finding with the abstract graph is, However, about 1.5~6.6% more than A* algorithm based on fixed-size cells because edges eliminated are not candidates for path-finding.

• Horticultural Science & Technology
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• v.18 no.4
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• pp.503-507
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• 2000

This study was conducted to investigate the effect of shoot training method on the plant growth and fruit quality and yield of 'Sinsakigake-2' and 'Shishito' peppers (Capsicum annuum L.) grown in the glasshouse. Plants were either left untrained as control or trained at the third node leaving two or four shoots per plant. The untrained control plants had no pruning and therefore had all the lateral branches. The growth was enhanced in plants with two trained shoots in both cultivars. Fruit length and width, fruit weight, and pericarp thickness were not affected by the number of shoots trained. However, the percent marketable fruits was the highest in plants with two trained shoots, and the number of marketable fruits per plant was the highest in plants with four trained shoots. Marketable yield in plants with four trained shoots increased 15% in 'Sinsakigake-2' and 5% in 'Shishito' as compared to that of the control. Results of this study showed that yield and quality of pepper fruits were promoted by training with four shoots and the effect was more pronounced in 'Sinsakigake-2' than 'Shishito' pepper.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.407-412
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• 2011

The germination of the buds in 'Hongisul' grapes is poor and especially the high ratio of shoots where the flowers failed to emerge it was difficult to secure a sufficient amount of harvest. Thus, in this study, the necrosis and the periodical change in the buds were observed morphologically and also the cause of necrosis of the bud was investigated in order to understand what was causing the low germination and flowering. There was no change in the size of the bud after June and based upon external observation, there wasn't any retrogression or withering. However, based on a microscopic examination, the ratio of whole bud and main bud necrosis of the 'Hongisul' grapes continued to increase after August, and specially the ratio of the main bud necrosis continued to increase up to October. As for the size of the buds on the shoots, the buds located on the $1^{st}-3^{rd}$ nodes from the basal part were small whereas the buds located on the $4-10^{th}$ nodes were comparatively larger in its size. The ratio of necrosis of the bud was the highest at the $1^{st}$ and $2^{nd}$ bud, meaning that the buds located at the basal part of the shoot were defective compared to those located at the end of the shoot. It was also found that when the growth of the shoot is active and the shoot diameter is thick, it hindered the development of the buds. Therefore, it was judged that long pruning of 'Hongisul' grapes would help the emergence of the flowers as you could use the buds that have comparatively developed better.