• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.24 no.68
• /
• pp.21-30
• /
• 2001

The purpose of this study is to present methods for determining the k most vital arcs (k-MVAs) in the minimum spanning tree problem(MSTP) using evolutionary algorithms. The problem of finding the k-MVAs in MSTP is to find a set of k arcs whose simultaneous removal from the network causes the greatest increase in the total length of minimum spanning tree. Generally, the problem which determine the k-MVAs in MSTP has known as NP-hard. Therefore, in order to deal with the problem of real world the heuristic algorithms are needed. In this study we propose to three genetic algorithms as the heuristic methods for finding the k-MVAs in MSTP. The algorithms to be presented in this study are developed using the library of the evolutionary algorithm framework(EAF) and the performance of the algorithms are analyzed through the computer experiment.

• Journal of Life Science
• /
• v.15 no.1 s.68
• /
• pp.21-26
• /
• 2005

This study officially selected Kalopanax pictus. The root cutting and investigation conducted how the production process of the rooting ratio according to its age and its length gives some influence to the rooting ratio and what is the usage value in the effect of rooting ratio of an accelerant of plant growth and IBA treatment. The ages and ratio of rooting are one year $92.0\%$, two years $80.0\%$, and three years $67.0\%$. As shown above, one year cutting showed the highest growth. The rooting ratio by the length of the cutting-tree is $75.0\%$ in 5cm, $92.0\%$ in 10cm and $89.0\%$ in 15cm. There is a little differences according to the result of each analysis in the rooting ratio by the length of the cutting tree. Two groups having the length 10cm and 15cm showed the similar rooting ratio, while the group having the length 5cm showed that the rooting ratio is very low. The rooting ratio treated by the hormone, IBA showed that the treated group was $94\%$ and the untreated group was $92\%$. Although the treated group showed a little high rooting growth ratio, there was no significant difference. Thus, it is said that the treatment of IBA in the cutting tree is insignificant.

• Journal of Conservation Science
• /
• v.38 no.2
• /
• pp.109-116
• /
• 2022

This study identified Korean red pine (Pinus densiflora) and exotic pines (Pinus resinosa, Pinus sylvestris) with a similar anatomical structure using a dendro-anatomical method that applied dendrochronology, tracheid length, and uniseriate ray cell size. Korean red pine samples were collected from 13 national parks, while exotic pine samples were secured from two wood importers. Tracheid length was measured by distinguishing earlywood from latewood, and uniseriate ray height and cell number were determined. As the exotic pine tree-ring chronology was consistent with the foreign standard tree-ring chronology and displayed high statistical significance, the country and region where the pine samples had been felled and the exact felling date were confirmed. According to the results, which compared tracheid length and uniseriate ray size, no difference was observed between the Korean red and Russian pines. However, the tracheid length of the Russian pines turned out to be slightly longer than the length of the Korean red pine. Additional research securing a larger number of exotic pines (P.resinosa, P.sylvestris) is required to yield more accurate results in the future.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.07a
• /
• pp.476-480
• /
• 2003

Polyethylene used as insulating material of power cable is nonpolar and low dielectric loss polymer. But it has defects of tree generation and accumulation of space charge by an applied voltage resulting in the decreased life and performance. To solve these problems, mixed films with LLDPE and EVA that is similar to LLDPE at physical properties in case of low VA contents were made and tested due to the blend ratios of 80:20, 70:30, 60:40 and 50:50[wt%] respectively. We investigated AC electrical treeing characteristics to acquire the best mixture ratio and effect of the tip radius of needle electrode to develop excellent treeproof materials. The degree of crystallity calculated with XRD pattern is higher for pure LLDPE, 50:50 and 70:30. For DSC analysis, it is confirmed that the melting points of mixed specimens are lower than that of pure LLDPE and higher than pure EVA's. The shape of tree propagation showed that pure EVA was electrical tree shape of the branch type, pure LLDPE and blended specimens was able to confirm tree shape of the bush type. As the tip radius go up in the blend ratio 70:30 specimen, the tree inception voltage rise. Probably the reason is the relaxation of electric field in the specimen with bigger tip ratio. As the 6 specimens were applied AC 5[KV],7.5[KV],10[KV] respectively, tree growth length is far shorter in the specimen with blend ratio 70:30, 50:50 than in pure EVA and pure LLDPE specimen. Conclusively, it is confirmed that specimens of which blend ratio are 70:30 and 50:50 are good in electrical tree retardant characteristics, especially, 70:30 has lower dielectric loss than 50:50 and its mixture ratio is the best.

• Journal of Digital Convergence
• /
• v.11 no.6
• /
• pp.221-233
• /
• 2013

This study aims to develop the severity-adjusted length of stay(LOS) model for acute stroke patients using data from the hospital discharge survey and propose management of length of stay(LOS) for acute stroke patients and using for Hospital management. The dataset was taken from 23,134 database of the hospital discharge survey from 2004 to 2009. The severity-adjusted LOS model for the acute stroke patients was developed by data mining analysis. From decision making tree model, the main reasons for LOS of acute stroke patients were acute stroke type. The difference between severity-adjusted LOS from the decision making tree model and real LOS was compared and it was confirmed that insurance type and bed number of hospital, location of hospital were statistically associated with LOS. And to conclude, hospitals should manage the LOS of acute stroke patients applying it into the medical information system.

• Animal cells and systems
• /
• v.14 no.2
• /
• pp.137-145
• /
• 2010

Four specimens of unknown Coilia sp. were collected for the first time from the Yellow Sea in 2008 and compared with Coilia mystus and Coilia nasus. Coilia sp. showed similar morphology to C. mystus and C. nasus, but differed in that its tail was considerably shorter. We conducted an analysis of the morphological and genetic characteristics in an effort to clarify the taxonomic position of Coilia sp. In counts and measurements, Coilia sp. were well distinguished from C. nasus by the number of scutes (42-44 in Coilia sp. vs. 40-45 in C. mystus vs. 45-55 in C. nasus), ratio of dorsal base length to head length (43.4-47.6 vs. 37.9-47.6 vs. 33.0-41.0), and eye length to head length (19.2-20.8 vs. 17.0-22.4 vs. 13.8-18.2). In caudal skeleton of Coilia sp., urostyle, hypural and epural bones were not observed; instead of them, caudal fin rays were supported by the last vertebra, neural and haemal spines' extension. The molecular phylogenetic relationship was analyzed using 414 base-pair 12S rRNA mitochondrial DNA sequences. The Kimura-2-parameter distance between Coilia sp. and C. mystus was 0.3%, but was 1.3% between Coilia sp. and C. nasus. Both the neighbor-joining tree and maximum-likelihood tree showed that Coilia sp. are closely clustered with C. mystus. Therefore, our results suggest that the Coilia sp. may be a deformed fish of C. mystus.

• Advances in environmental research
• /
• v.3 no.3
• /
• pp.207-216
• /
• 2014

A study was conducted to determine the phytotoxic effect of mercury on seed germination and seedling growth of an important arid legume tree Albizia lebbeck. The seeds germination and seedling growth performance of A. lebbeck responded differently to mercuric chloride treatment (1 mM, 3 mM, 5 mM and 7 mM) as compared to control. Seed germination of A. lebbeck was significantly (p < 0.05) affected by mercury treatment at 1 mM. Root growth of A. lebbeck was not significantly affected by mercury treatment at 1 mM, and 3 mM. Shoot and root length of A. lebbeck were significantly (p < 0.05) affected by 5 mM concentration of mercury treatment. Increase in concentration of mercury treatment at 5 mM and 7 mM significantly (p < 0.05) reduced seedling dry weight of A. lebbeck. The treatment of mercury at 1 mM decreased high percentage of seed germination (22%), seedling length (10%), root length (21.85%) and seedling dry weight (9%). Highest decrease in seed germination (51%), seedling (34%), root length (48%) and seedling dry weight (41%) of A. lebbeck occurred at 7 mM mercury treatment. A. lebbeck showed high percentage of tolerance (78.14%) to mercury at 1 mM. However, 7 mM concentration of mercury produced lowest percentage of tolerance (51.65%) in A. lebbeck. The seed germination potential and seedling vigor index (SVI) clearly decreased with the higher level of mercury. Plantation of A. lebbeck in mercury-polluted area will help in reducing the burden of mercury pollution. A. lebbeck can serve better in coordinating in land management programs in metal contaminated areas. The identification of the toxic concentration of metals and tolerance indices of A. lebbeck would also be helpful for the establishment of air quality standard.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.10a
• /
• pp.585-588
• /
• 2010

The prediction of user location within a building can be applied to many areas like visitor guiding. The existing methods for solving this problem consider limited number of locations a user visited in the past to predict the current location. It cannot model the complex movement patterns, and makes the system inefficient by modeling simple ones too detail. Also it causes prediction errors. In this paper, there is no restriction on the length of past movement patterns to consider for current location prediction. For this purpose, a modified search tree is used. The search tree is constructed to make exact matching as needed for location prediction. The search tree makes the efficient and accurate prediction possible.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.6 no.5
• /
• pp.28-39
• /
• 2003

This study was carried out to elucidate effective restoration measures for natural forest with recycling native tree un site from November 2001 to October 2002 to obtain a basic information for revegetation measure, eight experimental treatment was done and the length of stump, root-ball size of stump, antisepsis treatment of trunk cut, Planting season and contents of organic matter in soil were effective on regrowth of root-stock. Thirteen tree species including Quercus acutissima among twenty tree species showed outstanding sprout and survival rate(over 90 percent), Planting in November and combinated planting with 5 trees and 9 shrubs of root-stock per 100$m^2$ plot showed a good growth. And 10 percent of organic matter plot showed a good crown coverage.

• Journal of Korean Society of Forest Science
• /
• v.111 no.4
• /
• pp.548-556
• /
• 2022

In this study, basic data were obtained to determine the optimal cultivation method to achieve stable fruiting and yield increase in "Cheonhwang" jujube trees. Accordingly, thefructification, fruit characteristics, and yield according to tree age were analyzed. The mean (and range of) tree height, crown area, stem diameter near the root, clear stem length, number of main branches, and distance between main branches were 235.6 (217.4-253.8) cm, 3.5 (3.1-4.1) m², 5.5 (4.0-7.1) cm, 70.6 (66.2-72.7) cm, 9.7 (8.6-10.5), and 10.4 (7.9-14.2) cm, respectively. Correlationanalysis results indicated that tree age was positively correlated with crown area, stem diameter near the root, and clear stem length but not with the number of main branches. The mean number (and range) of fruit per fruit-bearing mother shoot and tree were 18.3 (16.7-18.3) and 170.7 (157.9-178.3), respectively. Tree age was not significantlycorrelated with fruiting characteristics (i.e., the numbers of fruit-bearing mother shoots per main branch, fruit-bearing shoots per fruit-bearing mother shoot, fruit per fruit-bearing shoot, and fruit per tree). Given that the shape of jujube trees is constantly managed according to the growing area and greenhouse type, the tree growth characteristics were more affected by tree management techniques than by tree age. The mean (and range of) fruit weight, fruit hardness, and soluble solid content were 28.6 (27.7-30.3) g, 29.4 (28.5-30.4) N, and 20.4 (19.3-21.0) °brix, respectively, and these fruit characteristics were not significantly correlated with tree age.The average yield per tree of the 'Cheonhwang' jujube cultivar was 4.9 (4.8-5.0) kg, which was not significantly correlated with tree age.