• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.161-169
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• 2013

This study was carried out to examine characteristics of physical and chemical current status and problems of Salix spp. communities based on growth characteristics by tree age and height of the tree species in around Namgang Dam reservoir area. Tree density in 4 survey areas was 5,284 trees/ha, but all areas need to control high tree density. Tree crown area in 4 survey areas was 9,786.4 $m^2/ha$ and crown area of Salix spp. was the most dominant among tree species in watershed of the Jinyang lake. Mean soil depth in 4 survey areas was 65.5 cm higher in the sedimental deposit soil (78 cm) than in forest soil (12.5 cm) near the watershed. Soil bulk density was also higher in the sedimental deposit soil than in forest soil because of poor porosity in the sandy sediment. Soil pH was higher in sedimental deposit soil (A, B horizon:pH 6.7) than in forest soil (A horizon:pH 5.3; B horizon:pH 5.2) because of originated from non-point source polution and detergent of domestic sewage. The results suggest that growth of Salix spp. could be poor because of low fertility with low cation exchange capacity in sedimental deposit soil.

• Journal of Korea Foresty Energy
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• v.22 no.3
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• pp.20-28
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• 2003

This study was subjected to compare seasonal changes of survival rate, relative growth rate, and chlorophyll contents of major oak tree species including Quercus acctissima, Quercus mongolica, Quercus serrata, Quercus varibilis seedlings grown in Quercus acctissima forest under different light intensities. Three light intensities were 81% of sunlight, 34% of sunlight and 21% of sunlight. In each treatment, 100 tree seedlings were planted and survival rate, growth rate, and chlorophyll contents were measured. The highest survival rate was Quercus acctissima in 73% seedlings compared with those subjected to the other tree seedlings in 45~66%. Lowest survival rate was Quercus vnriabilis seedlings in 41%. Oaks tree species of the height, the root collar diameters of the relative growth were better in the seedlings grown in 81% light intensities of full sun. But growth rates decreased rapidly in the shade treatment of 21% light intensities of full sun. Lowest chlorophyll contents(chlorophyll a, b and total) were shown at 21% light intensities of full sun, lowest light intensity treatment in this study This result is thought growth and chlorophyll contents associated with light intensity Also, Physiological characteristics has to be investigated in near future because photosynthesis and chlorophyll contents were strongly related to tree growth with long periods.

• Journal of the Korea Society of Computer and Information
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• v.20 no.5
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• pp.1-12
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• 2015

NAND flash memory has being used for storage systems widely, because it has good features which are low-price, low-power and fast access speed. However, NAND flash memory has an in-place update problem, and therefore it needs FTL(flash translation layer) to run for applications based on hard disk storage. The FTL includes complex functions, such as address mapping, garbage collection, wear leveling and so on. Futhermore, implementation of the FTL on low-power embedded systems is difficult due to its memory requirements and operation overhead. Accordingly, many index data structures for NAND flash memory have being studied for the embedded systems. Overall performances of the index data structures are enhanced by a decreasing of page write counts, whereas it has increased page read counts, as a side effect. Therefore, we propose an index management method using a page mapping log table in $B^+$-Tree based on NAND flash memory to decrease page write counts and not to increase page read counts. The page mapping log table registers page address information of changed index node and then it is exploited when retrieving records. In our experiment, the proposed method reduces the page read counts about 61% at maximum and the page write counts about 31% at maximum, compared to the related studies of index data structures.

• Journal of Korean Society of Forest Science
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• v.34 no.1
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• pp.21-30
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• 1977

Japanese larch (Larix leptolepis) is one of main timber species in Korea that could find much plantation and growing stands on all over the country. It is thought to be in meaningful that a guiding diagram for density control of Japanese larch stands is made to estimate easily the density conditions in the quantitaive, ecological and economic viewpoint. Sample plots for this study are selected from the stands that have not been thinned in recent years, and mean height, mean diameter, dominant height, tree numbers per hectare and stem volume of mean tree are calculated from the each sample plots among total 165 plots In this study, especially, the theory of slenderness of mean tree are applied, that have been identified through the results of the spacing trial. Relative growth characteristics of this species are calculated from the general logistic curve and its formula is $Y=ax^b$. Relatwion between the measured items are found out as follows: 1. Relation between the mean height and tree numbers per hectare by slender class is showing the high correlation as table 1 and fig. 2, and between mean diameter and tree numbers per hectare is also high correlation as table 1 and fig 3. 2. The stem volume can be correctly estimated from height in case that slender class may be known, as showing in table 3 and fig. 4. 3. The stem volume can be more correctly estimated from the relation with $D^2H$ as formula, $Log_e\;V=0.9569\;Log_eD^2H-9.8431$, and relation between stem volume of single tree or volume per hectare and tree numbers per hectare are as following formulas: $Log_e$ stem volume=9.5026-1.6800 $Log_e$ tree numbers per hectare $Log_e$ stem volume per hectare=9.4911-0.6784 $Log_e$ tree numbers per hectare. Stem volume of mean tree, tree numbers per hectare and stem volume per hectare correspond to the mean tree height are calculated to slender class as table 5, 6, 7. Through the above steps, the diagram for density control of Japanese larch are produced as fig. 9. It is thought that this diagram could be applied to control the density of Japanese larch stands.

• Journal of Life Science
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• v.23 no.1
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• pp.24-30
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• 2013

The purpose of this study was to identify genetic polymorphisms of the mitochondrial cytochrome b (mtDNA cyt b) gene in Korean black (KB) cattle breed and to analyze the genetic relationship between the KB and other breeds. We determined the complete sequence of the mtDNA cyt b gene in 38 KB cattle. We also analyzed their genetic diversity, and phylogenetic analysis was performed by comparison with Korean cattle (KC, called Hanwoo) and breeds from China and Japan. A nucleotide substitution was detected in the KB cattle, and two haplotypes were defined. In the neighbor-joining (NJ) tree, the haplotypes of KB were located in Bos taurus lineage with those of KC, Japanese black (JB), Yanbian and Zaosheng breeds. However, the haplotypes of Chinese breeds, excluding Yanbian and Zaosheng, were separated into B. taurus and B. indicus lineages. In the NJ tree of breeds based on Dxy genetic distances, Chinese breeds mixed with B. taurus and B. indicus lineages were located between B. indicus and B. taurus lineages. KB was contained within B. taurus lineage and was determined to be genetically more closely related to two Chinese (Yanbian and Zaosheng) breeds than to KC and JB. The haplotype distribution and the results of the phylogenetic analysis suggest that KB and KC have genetic differences in their mtDNA cyt b gene sequences.

• Journal of Forest and Environmental Science
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• v.36 no.2
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• pp.143-155
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• 2020

A juniper pocket rot fungus, Pyrofomes demidoffii is a basidiomycetous fungus responsible for damage of living Juniperus spp. However, its effect on the residual strength and on the extent of decay of juniper's trunk was not determined in any prior studies. The purpose of this study was to study the features of J. procera infected by P. demdoffii, and to estimate the level of strength loss and decay severity in the trunk at D.B.H height using different five formulas. Infected juniper stands were examined in two Ethiopian forests through Visual Tree Assessment (VTA) followed by a slight destructive drilling of the trunk at D.B.H height. The decayed juniper tree is characterized by partially degraded lignin material at incipient stage of decay to completely degraded lignin material at final stage of decay. In the evaluated formulas, results of ANOVA showed that a significantly higher mean percentage of strength loss and decay severity were recorded in the trees of larger D.B.H categories (p<0.001). The strength loss formulas produced the same to similar patterns of sum of ranks of strength loss or decay severity in the trunk, but the differences varied significantly among D.B.H categories in Kruskal Wallis-test (p<0.001). In conclusion, the employed formulas showed similar to different degree of variability in quantification of strength loss or decay severity in the trunk. The findings of our study could be used as the baseline for further study on juniper's strength loss or decays in the trunk of Juniperus spp. and unequivocally helps to design the corresponding management as result of P. demidoffii.

• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.289-295
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• 2003

This is a part of study on the hydrolysis of seaweed using microorganisms. A microflora sample obtained from a decayed pine tree was purified by pure culture of 4 times. As the result, 16 isolated strains were obtained from the microflora sample and then each strain was incubated in a liquid medium with sea tangle powder for 3 weeks. Ratios of reduced sugar to total sugar of 08A211, 08C221 and 08B121 strains were highest. Accordingly, these three strains were incubated in 3 different liquid media of sodium alginate, sea tangle powder, and sea mustard powder for 3 or 4 weeks. The ratios of reduced sugar to total sugar and cell growth were measured once a week. Cell growth and ratios of reduced sugar to total sugar was highest for 08B121 in all the liquid media.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.6
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• pp.721-729
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• 2018

GABAergic control over dopamine (DA) neurons in the substantia nigra is crucial for determining firing rates and patterns. Although GABA activates both $GABA_A$ and $GABA_B$ receptors distributed throughout the somatodendritic tree, it is currently unclear how regional GABA receptors in the soma and dendritic compartments regulate spontaneous firing. Therefore, the objective of this study was to determine actions of regional GABA receptors on spontaneous firing in acutely dissociated DA neurons from the rat using patch-clamp and local GABA-uncaging techniques. Agonists and antagonists experiments showed that activation of either $GABA_A$ receptors or $GABA_B$ receptors in DA neurons is enough to completely abolish spontaneous firing. Local GABA-uncaging along the somatodendritic tree revealed that activation of regional GABA receptors limited within the soma, proximal, or distal dendritic region, can completely suppress spontaneous firing. However, activation of either $GABA_A$ or $GABA_B$ receptor equally suppressed spontaneous firing in the soma, whereas $GABA_B$ receptor inhibited spontaneous firing more strongly than $GABA_A$ receptor in the proximal and distal dendrites. These regional differences of GABA signals between the soma and dendritic compartments could contribute to our understanding of many diverse and complex actions of GABA in midbrain DA neurons.

• The Journal of the Korea Contents Association
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• v.7 no.7
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• pp.11-23
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• 2007

Applications involving moving objects require index structures to handle frequent updates of objects' locations efficiently. Several methods to index the current, the past and the future positions of moving objects have been proposed for the applications. Most of them are based on R-tree like index structures. Some researches have made efforts to improve update performance of R-trees that are actually focused on query performance. Even though the update performance is improved by researchers' efforts, the overhead and immaturity of concurrency control algorithms of R-trees makes us hesitate to choose them for moving objects. In this paper, we propose an update efficient indexing method that can be applicable for indexing the past, the current and the future locations. The proposed index is based on B+-Trees and Hilbert curve. We present an advanced Hilbert curve that adjusts automatically the order of Hilbert curve in subregions according to the data distribution and the number of data objects. Through empirical studies, we show that our strategy achieves higher response time and throughput.

• Toxicological Research
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• v.23 no.1
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• pp.19-24
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• 2007

We demonstrate that paclitaxel, an antitumor agent derived from yew tree, inhibits LPS- and $IFN-{\gamma}$-induced NF-kB/Rel activation in RAW 264.7 cells. Previously, paclitaxel ($>10{\mu}M$) has been known to induce iNOS gene expression in macrophages. However, in the previous report we described that the pretreatment of macrophages with low concentration of paclitaxel ($0.1{\mu}M$) for 8 h inhibited LPS-induced iNOS gene expression. Pretreatment of RAW 264.7 cells with paclitaxel significantly inhibited NF-kB/Rel transcriptional activation. Electrophoretic mobility shift assay further confirmed that pretreatment of macrophages with paclitaxel inhibited NF-kB/Rel DNA binding. Taxotere, a semisynthetic analog of paclitaxel, also inhibited LPS- and $IFN-{\gamma}$-induced iNOS gene expression. Collectively, these series of experiments indicate that paclitaxel inhibits iNOS gene expression by blocking NF-kB/Rel activation.