• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2060-2062
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• 1999

When the high voltage is applied on insulation materials that have voids and impurities inner one, then probability of electrical tree inception is increased at defects. Electrical tree gives a profit to degradation analysis, because it is possible to observe by eyes and provides electrical degradation step. And electrical tree is divided to three types in usual - tree type, bush type and chestnut type tree. But these three types are divided not by method of quantitative analysis but visual and experiential analysis. In this paper, three types of electrical tree were calculated by quantitative analysis using fractal mathematics and classified to fractal dimensions (FD). FD of tree types are 1.1$\sim$1.4, bush types are 1.4$\sim$1.6 and chestnut type trees have above 1.6 FD.

• Journal of the Korean Wood Science and Technology
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• v.13 no.3
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• pp.41-48
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• 1985

In near future about 500,000 hectares of Japanese larch and pitch pine need thinning to improve crop-tree spacing and reasonable species composition in Korea. Although thinned trees show very little high quality wood, in fact, all the sawed products are suitable for construction and farming materials. Studies on the utilization of thinned small-diameter trees have been implemented in order to increase lumber yield and display the skeleton of farm buildings. The results obtained in this study were summarized as follows: 1. According to Korean Conifers Log Grading System, log grade 3 was 87.4 percent in Japanese larch bolts and 95.8 percent in pitch pine bolts from thinned trees. The ability to identify defects was essential for grading logs. 2. Cutting diagrams of sawing were developed for 1-sided sawing, 2-sided sawing and 3-sided sawing by small end diameter class of bolt and cutting sizes also were found to use effectively lumber with wane. 3. Lumber recovery of Pitch pine was a little higher than that of Japanese larch. The maximum lumber yields of pitch pine by sawing patterns were 87.2 percent for 1-sided sawing, 80.8 percent for 2-sided sawing an 64.1 percent for 3-sided sawing, up yield compared with 58.1 percent for 4-sided sawing. The lumber yield of 1, 2 and 3-sided sawing significantly was higher value than that of 4-sided sawing. 4. Lumber was inspected and graded. Lumber quality of diameter class 12cm was a little better than that of diameter class 8cm, but 90 percent of lumber in diameter c1ass 16cm fell into grade 3. The lumber grade was classified by Korean standard grades of confiers lumber. 5. Lumber from 1, 2 and 3-sided sawing was used to build the skeleton of a farm house ($53m^2$) and greenhouse ($60m^2$) in order to display more efficient use of small diameter trees from thinning 6. Total volume of timber for building a farm house was $8.1m^3$ of imported timber. Timber of $7m^3$, 70 percent of total volume would be substituted imported timber for domestic timber.

• Journal of the Korean Institute of Intelligent Systems
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• v.9 no.4
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• pp.367-374
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• 1999

This paper suggests an integrated method based on concept ascension and attribute reduction for efficient induction of decision rules from a large database. We study an automatic scheme to generate concept trees by a clustering technique, a method for generalizing databases by the concept ascension technique, an optimal reduction method by means of attributes reduction using the sibmificance of attributes, and an efficient way of reduction of attribute values applying the discernible matrix and functions. The method can be used for the decision making tasks such as an investment planning or price evaluation, the construction of knowledge bases for diagnosis of defects or medical diagnosis, data analysis such as marketing or experimental data, information retrieval for high level inquiries, and so on.

• Journal of Korean Society of Forest Science
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• v.107 no.4
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• pp.344-350
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• 2018

This study was carried out to improve the forest management method considering the use of high value added timber in the natural broadleaf forests. For this purpose, the criteria for evaluating the quality grade of standing trees were established and applied to the oak stand in the central region of Korea. The evaluation factors of the grade were bending of stem, branch, stem damage, and other defects. If the logs are divided into 2.1 m units and three logs up to 6.3 m are available, they are classified as Grade I (G-I). If two logs are available, they are classified as Grade II (G-II), If only one log is available, it is classified as Grade III (G-III). When any log is not available as timber, it is classified as Grade IV (G-IV). As a result of applying the grade to the oak stand, G-I was 6.7 %, G-II was 28.0 %, G-III was 38.3 %, and G-IV was 27.0 %. The ratio of standing trees by oak species of higher than G-III was 88.2 % for Quercus acutissima, 88.1 % for Q. variabilis, 83.5 % for Q. serrata, 56.3 % for Q. aliena, and 50.3 % for Q. mongolica, respectively. The G-IV ratio for Q. variabilis and Q. mongolica tended to decrease with increasing diameter at breast height. The order of major defect affecting the grading level was bending of stem > branch > stem damage > other defects. Considering the grade level and oak species distribution, it was concluded possible to produce high quality hardwood timber when we concentrate forest tending techniques on Q. acutissima and Q. variabilis stand. In order to improve the accuracy of grading, it is necessary to continuous complement through the monitoring research for evaluation factors.

• Tuberculosis and Respiratory Diseases
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• v.43 no.2
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• pp.251-256
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• 1996

Kartagener's syndrome, a congenital disease transmitted as an autosomal recessive illness with a prevalence of approximately 1:20,000 persons, is characterized by the triple association of situs inversus, bronchiectasis, and sinusitis. Affected persons have an incoordination of ciliary motility that leads to defective mucociliary transport, chronic bronchial infections. Kartagener's syndrome is a subset of the immotile cilia syndrome and therefore all patients with Kartagener's syndrome have immotile cilia with obvious ultrastructural defects in the ciliary axoneme. In the respiratory tract this inability presumably causes impaired clearance of mucus and inhaled particles and results in the chronic infections of the sinuses and bronchial trees that are characterized of the disease. The end-stage phenomenon in Kartagener's syndrome, respiratory or heart failure is a less common event and heart-lung transplantation is becoming an accepted therapy for patients with end-stage pulmonary disease in Kartagener's syndrome in many institutes. We report one case of Kartagener's syndrome in a 25-year-old young woman who was presented as respiratory and right heart failures, with review of literatures.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1552-1563
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• 2016

To examine the cognitive function of onion (Allium cepa L.) beverages (odourless and fortified), we analyzed in vitro neuronal cell protection against $H_2O_2$-induced cytotoxicity and performed in vivo tests on amyloid beta ($A{\beta}$)-induced cognitive dysfunction. Cellular oxidative stress and cell viability were evaluated by DCF-DA assay and MTT assay. These results show that fortified beverage resulted in better neuronal cell protection than odourless beverage at lower concentration ($0{\sim}100{\mu}g/mL$). Fortified beverage also showed more excellent acetylcholinesterase (AChE) inhibitory activity ($IC_{50}$: 4.20 mg/mL) than odourless beverage. The cognitive functions of odourless beverage and fortified beverage in $A{\beta}$-induced neurotoxicity were assessed by Y-maze, passive avoidance, and Morris water maze tests. The results show improved cognitive function in both groups treated with beverages. After in vivo tests, cholinergic activities were determined based on AChE inhibition and acetylcholine levels, and antioxidant activities were measured as SOD, oxidized glutathione (GSH)/total GSH ratio, and MDA levels in mouse brain tissue. In a Q-TOF UPLC/MS system, main compounds were analyzed as follows: odourless beverage (five types of sugars and three types of phenolics) and fortified beverages (six types of phenolics and two types of steroidal saponins).

• Korean Journal of Plant Resources
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• v.29 no.1
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• pp.136-142
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• 2016

Lespedeza species are mainly used for wildlife food and cover and for erosion control. The germination of these species can be enhanced after a fire occurrence in forest, which is known as fire-activated seeds to germinate. While the heat treatment could break seed dormancy of Lespedeza, its germination rate was quite low. We investigated that chemical scarification could promote germination of L. tomentosa. Seeds were soaked in 100% sulfuric acid (H₂SO₄) for 0, 1, 3, 6, 12, 24, 48, 96, 192, and 384 min, and then washed in distilled water for 24 h. Very few seeds were germinated in control (H₂SO₄ for 0 min). More than 90% of seeds were germinated in H₂SO₄ for 24, 48, and 92 min. However, some damage was observed in roots and cotyledons of seedling dipped in H₂SO₄ for a long time. To search the optimal soaking time in H₂SO₄ without defects, seeds scarified in H₂SO₄ for 30, 60, 90, 120, 150, 180, and 300 min were sown the commercial soil medium. Seeds treated with H₂SO₄ for 90 min and 150 min emerged by about 92% and 84%, respectively. Therefore, H₂SO₄ treatment could break the seed dormancy of Lespedeza species, and especially in case of L. tomentosa the optimal treatment time in sulfuric acid was one to two hours. Germination of L. tomentosa began promptly following the scarification and was completed within about one month, indicating that seeds has no physiological dormancy, just has physical dormancy.