• Spatial Information Research
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• v.7 no.2
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• pp.271-282
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• 1999

In this paper, we derived an efficient indexing scheme, SJ tree, which handles multi-attribute data and spatial join operations efficiently. In addition, a number of algorithms for manipulating multi-attribute data are given , together with their computational and I/O complexity . Moreover , we how that SJ tree is a kind of generalized B-tree. This means that SJ-tree can be easily implemented on existing built-in B-tree in most storage managers in the sense that the structure of SJ tree is like that of B-tree. The spatial join operation with spatial output is benchmarked using R-tree, B-tree, K-D-B tree, and SJ tree. Results from the benchmark test indicate that SJ tree out performance other indexing schemes on spatial join with point data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.59-62
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• 1999

Inception and propagation of electrical tree and properties of Partial discharge(PD) pulses accompanying with tree as a function of needle tip radius in low density polyethylene were discussed. To study on these characteristics in different tip radius, we used specimens with needle-plane electrode system made of LDPE, observed inception and propagation of electrical tree by optical microscope with computer and investigated the characteristics of the phase resolved PD pulses accompanying with propagation of electrical tree. The PD quantities detected and analysed were PD magnitude, mean phase angle, average discharge, and the statistical characteristics of the PD pulses. As the tip radius ${\gamma}$ increases, tree inception stress E$\sub$i/ converges to constance value. This result suggests that tree inception stress E$\sub$i/ increases due to stress relaxation when the tip radius is small. Branch-type electrical tree was formed When E$\sub$i/ is 640-750[kV/mm]. bush-type electrical tree when E$\sub$i/ is 370∼400[kV/mm], branch-like electrical tree when E$\sub$i/ is 370-400[kV/mm].

• Journal of the Korean Society of Food Culture
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• v.33 no.2
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• pp.104-111
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• 2018

This study aims to compare and analyze a willow tree (Salix Koreensis andersson) extract's antioxidant and anti-inflammatory activity by investigating its: total polyphenol, flavonoid content, SOD-like activity, DPPH vitality. the willow tree was induced with LPS to determine its active anti-inflammatory effects. as a result, the willow methanol extract showed a higher total polyphenol and flavonoid content than those of willow distilled water extract, but the willow distilled water extract showed a higher SOD than that of willow methanol extract. in its DPPH scavenging ability, the willow methanol extract's antioxidant activity was higher than that of the willow distilled water extract. the willow extract's measurements such as the production of NO, inflammatory cytokine ($TNF-{\alpha}$, IL-6 measurement) were significantly reduced as its concentration level went down. according to the research outcomes, when induced, he will extract's macrophage produces mediator-like substances such as NO and inflammatory cytokine that can be used to alleviate the inflammatory response. therefore, the willow tree proved to be a useful raw plant material for the products designed to combat inflammatory activities due to its natural antioxidant and anti-inflammatory response substances such as NO and cytokine.

• The Journal of Korean Medical History
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• v.33 no.1
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• pp.43-57
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• 2020

Essence of the Hwangchil tree (黃漆樹 Dendropanax morbiferus H.Lév.) has been used for various purposes, like waxing emperor's armors, covering an astrology board, or, during the Silla Dynasty, burying it to block something bad in the soil symbolically. Essence of the Hwangchil tree was known to have remarkable preservation effects such as waterproofing, damp-proofing, rust-proofing, and moth-proofing as well as not being easily peeled off from even soft surfaces like paper. There is a record in Prescriptions for Epidemic diseases of Cows, Horses, Sheep, and Pigs (牛馬羊猪染疫病治療方), published in 1541, of Hwangchil that is local to Jeju Island being used instead of benzoin (安息香), of burning Hwangchil, and of making cows inhale its smoke to prevent plague among them. Along the same lines, there are records in the Local Chronicle of Tamra (耽羅志) and the Book of Earth Geography (輿地圖書) that identify Hwangchil with benzoin. In Seonghosaseol (星湖僿說), a book written by Lee Yik in around 1760, it is acknowledged that Hwangchil could be medicinal herb. In 2000, Ahn Duk-Kyun registered the roots and branches of Hwangchil tree as 'Boncho' (本草 herbal medicine) in the Pictorial Book of Korean Medicinals (韓國本草圖鑑) and presented the method of taking it for medical purpose. Researchers have suggested that Hwangchil essence as well as diverse parts of the plant such as its roots, branches, leaves, flowers, fruits, and gum have various meaningful medicinal properties. Regarding the history and recent researches of using Hwangchil tree, it has various medicinal probabilities such as, 'dispersing miasma' (辟邪), 'opening holes' (開竅), 'waking the heart' (醒心), 'smoothing spirits' (安神), 'piercing the block' (疎泄), 'removing the old and welcoming the new' (去故生新). This paper contributes ideas about how to expand the uses of Hwangchil Tree.

• Proceedings of the Korea Database Society Conference
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• 1997.10a
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• pp.472-482
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• 1997

Multi-dimensional data play a crucial role in various fields, as like computer graphics, geographical information system, and multimedia applications. Indexing method fur multi-dimensional data Is a very Important factor in overall system performance. What is proposed in this paper is a new dynamic access method for spatial objects called HL-CIF(Hierarchically Layered Caltech Intermediate Form) tree which requires small amount of storage space and facilitates efficient query processing. HL-CIF tree is a combination of hierarchical management of spatial objects and CIF tree in which spatial objects and sub-regions are associated with representative points. HL-CIF tree adopts "centroid" of spatial objects as the representative point. By reflecting objects′sizes and positions in its structure, HL-CIF tree guarantees the high spatial locality of objects grouped in a sub-region rendering query processing more efficient.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.31-33
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• 2007

Devising an efficient one-pass frequent pattern mining algorithm has been an issue in data mining research in recent past. Pattern growth algorithms like FP-Growth which are found more efficient than candidate generation and test algorithms still require two database scans. Moreover, FP-growth approach requires rebuilding the base-tree while mining with different support counts. In this paper we propose an item-based tree, called I-Tree that not only efficiently mines frequent patterns with single database scan but also provides multiple mining scopes with multiple support thresholds. The 'build-once-mine-many' property of I-Tree allows it to construct the tree only once and perform mining operation several times with the variation of support count values.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.454-457
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• 2005

Mining frequent patterns in transaction databases, time-series databases, and many other kinds of databases has been studied popularly in data mining research. Most of the previous studies adopt an Apriori-like candidate set generation-and-test approach. However, candidate set generation is still costly, especially when there exist prolific patterns and/or long patterns. And calendar based on temporal association rules proposes the discovery of association rules along with their temporal patterns in terms of calendar schemas, but this approach is also adopt an Apriori-like candidate set generation. In this paper, we propose an efficient temporal frequent pattern mining using TFP-tree (Temporal Frequent Pattern tree). This approach has three advantages: (1) this method separates many partitions by according to maximum size domain and only scans the transaction once for reducing the I/O cost. (2) This method maintains all of transactions using FP-trees. (3) We only have the FP-trees of I-star pattern and other star pattern nodes only link them step by step for efficient mining and the saving memory. Our performance study shows that the TFP-tree is efficient and scalable for mining, and is about an order of magnitude faster than the Apriori algorithm and also faster than calendar based on temporal frequent pattern mining methods.

• Journal of Korea Multimedia Society
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• v.6 no.5
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• pp.753-768
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• 2003

In this paper, we propose a multi-dimensional index structure, tailed a VA(Vector Approximate)-tree that is constructed with vector approximates of multi-dimensional feature vectors. To save storage space for index structures, the VA-tree employs vector approximation concepts of VA-file that presents feature vectors with much smaller number of bits than original value. Since the VA-tree is a tree structure, it does not suffer from performance degradation owing to the increase of data. Also, even though the VA-tree is MBR(Minimum Bounding Region) based tree structure like a R-tree, its split algorithm never allows overlap between MBRs. We show through various experiments that our proposed VA-tree is a suitable index structure for large amount of multi-dimensional data.

• Journal of KIISE:Databases
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• v.34 no.2
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• pp.109-118
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• 2007

Recently, flash memory is used to store data in mobile computing devices such as PDAs, SmartCards, mobile phones and MP3 players. These devices need index structures like the B-tree to efficiently support some operations like insertion, deletion and search. The BFTL(B-tree Flash Translation Layer) technique was first introduced which is for implementing the B-tree on flash memory. Flash memory has characteristics that a write operation is more costly than a read operation and an overwrite operation is impossible. Therefore, the BFTL method focuses on minimizing the number of write operations resulting from building the B-tree. However, we indicate in this paper that there are many rooms of improving the performance of the I/O cost in building the B-tree using this method and it is not practical since it increases highly the usage of the SRAM memory storage. In this paper, we propose a BOF(the B-tree On Flash memory) approach for implementing the B-tree on flash memory efficiently. The core of this approach is to store index units belonging to the same B-tree node to the same sector on flash memory in case of the replacement of the buffer used to build the B-tree. In this paper, we show that our BOF technique outperforms the BFTL or other techniques.

• Journal of Forest and Environmental Science
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• v.25 no.1
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• pp.1-24
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• 2009

Teak (Tectona grandis) is one of the most valuable timber yielding species in the world, with predominant distribution in tropical or sub-tropical countries. However, natural teak available only in few countries like India, Myanmar, Laos People's Democratic Republic and Thailand. Teak grows well in deep, well-drained alluvial soils, fairly moist, warm, tropical climate with pH ranges from 6.5-7.5. Teak is cultivated in many Asian, African and South American countries for timber production. The global teak plantations are estimated to be three million hectare with major share in India (44%) followed by Indonesia (33%). India is considered as richest genetic resources of teak with large areas of natural teak bearing forests (8.9 million ha), plantations (1.5 million ha), clonal seed orchards (1000 ha) and seed production areas (5000 ha). The studies on diversity of teak populations showed that teak is an out crossing species with major portion of diversity present within the populations. The productivity and quality of teak timber varies depending upon the site and environmental conditions. Teak wood is moderately heavy, strong and tough,straight grained, coarse textured and ring porous with specific gravity varies from 0.55 to 0.70. The sapwood is white to pale yellow in colour and clearly demarcated while heartwood is dark brown or dark golden yellow in colour. Teak is one of the most durable timbers in the world, practically, impervious to fungus and white ant attack and resistant to decay. Teak wood is used in ship and boat constructions, furnitures and aesthetic needs. Genetic improvement programmes have been undertaken in countries like Thailand, India, Malaysia and Indonesia. The programme includes provenance identification and testing, plus tree selection and clonal multiplication, establishment of seed orchards and controlled hybridization. Several aspects like phenology, reproductive biology, fruit characteristics, silvicultural practices for cultivation, pest and diseases problems, production of improved planting stock, harvesting and marketing, wood properties and future tree improvement strategy to enhance productivity have been discussed in this paper.