• Journal of Forest and Environmental Science
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• v.18 no.1
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• pp.45-52
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• 2001

This paper investigated external factors (height. crown width. diameter breath height, clear length) of tree and electric resistance ($k{\Omega}$) in damaged forest by Thecodiplosis japonensis Uchida et Inouye. The height. crown width and diameter breath height of tree external factors have high a coefficient of correlation. but clear length has not a coefficient of correlation. In relationship of electric resistance and external factor. big tree that height. crown width. diameter breath height has lower electric resistance value than that of small tree. (low electric resistance value is high tree vigor, high electric resistance value is low tree vigor)) Dead tree have smaller diameter breath height. crown width. higher clear length than survival tree in damaged forest by Thecodiplosis japonensis Uchida et Inouye. To investigation of relationship external factors according to electric resistance value. electric resistance value was divided three class (< $l4k{\Omega}$, possible of survival. $14{\sim}20k{\Omega}$, > $20k{\Omega}$, possible of dead). In lower class(< $l4k{\Omega}$), external factors have bigger which was height. crown width. diameter breath height and lower which was clear length than them of higher class ($14{\sim}20k{\Omega}$, > $20k{\Omega}$). Linear regression solutions of electric resistance and external factors were Y = -0.572 ${\times}$ Height - 1.163 ${\times}$ crown width - 0.242 ${\times}$ diameter breath height + 0.757 ${\times}$ clear length + 25.765. Regression solutions were significant in 5%.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.6
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• pp.605-614
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• 2015

Drone imaging, which is more cost-effective and controllable compared to airborne LiDAR, requires a low-cost camera and is used for capturing color images. From the overlapped color images, we produced two high-resolution digital surface models over different test areas. After segmentation, we performed tree identification according to the method proposed by , and computed the tree height and the canopy crown size. Compared with the field measurements, the computed results for the tree height in test area 1 (coniferous trees) were found to be accurate, while the results in test area 2 (deciduous coniferous trees) were found to be underestimated. The RMSE of the tree height was 0.84 m, and the width of the canopy crown was 1.51 m in test area 1. Further, the RMSE of the tree height was 2.45 m, and the width of the canopy crown was 1.53 m in test area 2. The experiment results validated the use of drone images for the extraction of a tree structure.

• Journal of Forest and Environmental Science
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• v.39 no.1
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• pp.20-26
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• 2023

Cow pea (Vigna unguiculata) was intercropped with Ziziphus spina-christi as summer forage in two consecutive seasons of 2017 and 2018. The aims to find out suitable agroforestry practice for saline soils of Khartoum State. And to investigate effect of tree spacing on forage biomass yield under semi -irrigated systems. Completely randomized block design with 3 replicates was conducted for this trial. Thus Z.spina-christi that fixed at 4×4 m was intercropped with cowpea at 1 m and 1.5 m spacing from trees trunk. Tree growth parameters were measured in terms of tree height, tree collar diameter, tree crown diameter and fruit yield per tree. While crop were parameters were determined in terms of plant height, number of plant, forage biomass yield per ha and land equivalent ratio. Soil profile of 1×1 m and 1.5 m depth was excavated and its features were described beside its chemical and physical properties were analyzed for 0-10 cm, 0-30 cm, and 30-60 cm and 60-100 cm layers. The results revealed that soil pH, CaCO₃, SAR, ESP, and EC ds/m were increased by increasing soil depths. Meanwhile tree growth in terms of tree height was significant in the first season 2017 when compared with tree collar diameter and tree crown diameter. Also significant differences were recorded for tree growth when compared with sole trees in the second season in 2018. Tree fruit showed marked variations between the two seasons, but it was higher under intercropping particularly at ZS2. Crop plant height was highly significant under sole cropping than intercropping in first season in 2017. In contrast forage biomass yield was significant under intercropping in ZS1 and ZS2 treatments. Land equivalent ratio was advantageous under this agroforestry system particularly under ZS2. Thus it recorded 5 and 9 for ZS2 in the two consecutive seasons respectively. Therefore, it is feasible to introduce this agroforestry system under such arid lands to provide summer forage yield of highly nutritive value and low cost for animals feed as well as to increase farmers' income and to halt desertification and to sequester carbon.

• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.758-762
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• 2008

Embedded systems usually utilize Flash Memories with very nice characteristics of non-volatility, low access time, low power and so on. For the multimedia database systems, R-tree is an indexing tree with nice characteristics for multimedia access. MR-tree, which is an upgraded version of R-tree, has shown better performance in searching, inserting and deleting operations than R-tree. Flash memory has sectors and blocks as a unit of read, write and delete operations. Especially, the delete is done on a unit of 512 byte blocks with very large operation time and it is also known that read and write operations on a unit of block matches caching nature of MT-tree. Our research optimizes MR-tree operations in a unit of Flash memory blocks. Such an adjusting leads in better indexing performance in database accesses. With MR-tree on a 512B block units we achieved fast search time of database indexing with low height of MR-tree as well as faster update time of database indexing with the best fit of flash memory blocks. Thus MR-tree with optimized operations shows good characteristics to be a database index schemes on any systems with flash memory.

• Journal of Korean Society of Forest Science
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• v.21 no.1
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• pp.39-45
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• 1974

The objects of this study are to induce the experimental equation suitable to estimate the height growing process, and to get some information that could be to reduce the error percent on determining the site index. The height growing process per sample plot were made up from the height age curve getted through the stem-analysis of the dominant tree. The 11 equations were calculated in the functional formulas between the age and the dominant height of Alnus hirsuta, Larix leptolepsis, L. Gmelini, P. koraiensis, Abies holophylla, P. rigida, Q. acutissima and Q. aliena. The suitable equation for estimating the guide curve were selected with the highest correlation and the low standard error with comparision on the age-height distributed map as Fig. 2. The suitable equation is different between the species as their calculated results as follows; The growing process of tree height are occasionally found to be polymorphous in the growth pattern as Fig. 3. By this result, the site index are practically found to be always not constant but shows variation to age in same plot as example 5. So, that the site index are estimated from the height-growth curve to age drawing by the stem-analysis or the polymorphic-curve, are concluded to be suitable on the study of site evaluation.

• Proceedings of the Korean Society of Life Science Conference
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• 2000.09a
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• pp.96-96
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• 2000

• Journal of Climate Change Research
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• v.6 no.4
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• pp.379-388
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• 2015

The purpose of the this study was to provide basic data on reasonable management for Abies koreana in Mt. Jiri through analysis the ecological characteristics of Abies koreana forests on Seseok. Due to low soil pH (4.26), high organic matter (10.5%) and total N (0.32%), the soil properties of A. koreana forest on Seseok are different from those of other forest soil in Korea. According to the result of importance value analysis, A. koreana (70.5) for tree layer, A. koreana (37.6) and Rhododendron schlippenbachii (20.8) for subtree layer and A. koreana (12.6), Sasa borealis (11.5) and Acer pseudosieboldianum (11.2) for shrub layer were high, respectively. The species diversity of Shannon was 0.425 for tree layer, 0.869 for subtree layer and 1.320 for shrub layer. Evenness and dominance for all layers ranged from 0.365 to 0.894 and 0.187 to 0.635, respectively. Height growth according to DBH of A. koreana on Seseok was relative high. Annual mean tree ring growth of A. koreana showed up 1.372, 1.557 and 1.483 mm/yr for small, middle and large diameter tree, respectively. Considering the importance value, distribution of seedling, height growth and ring growth, A. koreana forest on Seseok in Mt. Jiri will be maintained as the major population from now on.

• Journal of Forest and Environmental Science
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• v.16 no.1
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• pp.34-41
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• 2000

This study investigated tree vigor of damaged forest by Thecodiplosis japonensis Uchida et Inouye. In damaged forest by pine gall midge, the investigation result of damaged rate section (severe, moderate, light) indicated that severe stand showed higher value of electric resistance ($k{\Omega}$) than that of light stand, the investigation result of tree density section(crowed, middle, little) indicated that crowed stand showed higher value of electric resistance than that of little stand (the value of electric resistance at which low reading show high vigor tree and high reading low vigor tree). The crown width and DBH (diameter of breast height) of external factors showed lower value of electric resistance than that of small size. The results of comparative between Crown area and value of electric resistance in each stand were $13.4m^2$ in severe stand, $10.9m^2$ in moderate stand and $7.9m^2$ in light stand. Therefore, the tree which have big crown showed low value of electric resistance (below $15k{\Omega}$)that has high possible of survial.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.634-643
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• 2016

In this study, we compare the quality of the mango cv. Irwin cultivated in Jeju and Okinawa by evaluating the total soluble solids (TSS) and antioxidant activity (AA) from ethanol extracts of the fruit. TSS and AA were higher in fruit cultivated at the Research Institute of Climate Change and Agriculture in Jeju (RICA) and Okinawa farm, where the low tree height cultivation method is used, than in fruit cultivated on farm in Jeju. Also, the mangiferin content of the Okinawa farm was higher than those produced on the RICA and Jeju farm house. These results suggest that the lowering tree height cultivation method improves the quality of the mango cv. Irwin.

• Journal of the Korean Wood Science and Technology
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• v.47 no.5
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• pp.633-643
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• 2019

Growth characteristics [stem diameter (D), tree height (H)] and wood properties [Pilodyn penetration (P) and stress-wave velocity (SWV)] were measured for 65 families of 6-year-old Acacia mangium trees planted in Indonesia, in order to characterize their variation in D, H, P, and SWV. Therefore, the correlations between the measured characteristics were also determined, and their significant differences observed. Furthermore, their low to moderate values of narrow-sense heritability was obtained, and the results indicated the characteristics to be genetically controlled in A. mangium. In addition, highly significant positive correlations were observed among the growth characteristics, suggesting a close relationship, while there was no significant association between the growth characteristics and P, as well as SWV, indicating their independent. Therefore, these results demonstrate a potential for the improvement of both growth and wood properties of A. mangium trees, using the appropriate breeding programs. In addition, 18 families showed good performance in D and SWV, signifying their positive prospect of being considered as plus trees for the next generation breeding cycles.