• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.1
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• pp.17-25
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• 1986

Discussions on this paper are related to the effects of organic materials to treeing phenomena of low density polyethylene. As additives, 11 kinds of organic compounds are selected by considering the respective features such as melting point, boiling point, electron affinity as well as molecular structure, and then the specimens of low density polyethylene are prepared by blending with 10wt% of the selected additives. For the comparison of effectiveness of treeing resistance and interpretation of the mechanism of compounds as treeing retardants, several investigations such as the tree acceleration test, the prestressed test and the measurement of internally occurred partial discharge are carried out. As the results, meta-Cresol is regard as the most effective retardant among those, and it is supposed that this aromatic compound to be comprised of radical having large electron affinity has strong capability to accept energetic electron to prevent or delay the growth of discharge streamer. Furthermore, by activating partial discharge at the wall of tree pit through the function of trapped electron at this material, the gas pressure in the pit is increased up to prevent the growth of streamer.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.2 s.115
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• pp.26-35
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• 2006

The purpose of this research is to suggest the planting methods and the reasonable target levels of IGS for promoting green streetscape in Seoul. Using the three dimensional computer simulations, various greening methods were applied to evaluate effectiveness of promoting green streetscape. The results of this study suggest that promoting tree planting on car lane is more effective than on pedestrian side walks. In wide streets, the height of tree has positive effects on promoting green streetscape. In both car lane and pedestrian side walks, the greening effects of tree planting both in zig-zag pattern and in parallel pattern were similarly most high. The width of strip in side strip planting has positive effect on promoting green streetscape. Promoting stratified planting is very effective. Promoting greening wall on pedestrian side walks is more effective than on car lane. Combined the results of IGS survey with the public officials and complex simulations, suggest that the optimal levels of IGS is ranging from 12.0% in alleys to 54.0% in car lanes among arterial roads.

• Journal of the Korean housing association
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• v.15 no.1
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• pp.153-161
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• 2004

The purpose of this study is to analysis the environmental characteristics in the small urban village consist of the detached houses. Three detached houses with the different urban structure and physical characteristics are selected, we survey the physical characteristics and investigate the residential satisfaction. As a result of the study, (1) A loop street pattern is more desirable for a community than a grid pattern, (2) The wall of the residential boundary makes residents get the sense of territory and community, and it facilitates no wall or tree fence of the each detached house. (3) The community spaces have an effect up on the sense of community. (4) It is desirable that the residents participate in a management of the detached housing area.

• Journal of agriculture & life science
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• v.45 no.1
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• pp.9-14
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• 2011

Larix kaempferi is a tree with a major economic impact and is processed in large quantity every year in Korea. This study was carried out to collect basic data for the reasonable use of Larix kaempferi and to investigate the relation between anatomical properties and modulus of rupture (MOR) for heartwood and sapwood. As the length of earlywood tracheid and the radial wall thickness of earlywood tracheid and latewood tracheid increased, the modulus of rupture (MOR) increased, but decreased with increasing microfibril angle. Statistical analysis by the stepwise regression technique shows that the main factors affecting the modulus of rupture (MOR) of heartwood are the microfibril angle and the radial wall thickness of latewood tracheid, while those affecting MOR of sapwood are the length of earlywood tracheid and the microfibril angle.

• Journal of Korean Society of Forest Science
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• v.34 no.1
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• pp.47-56
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• 1977

I have investigated and compared the morphology of vascular bundle shown in the section of culm wall of bamboo trees growing on Mt. Jiri which were classified by Grosser and Liese with their methods of morphological classification. The results obtained were as follows: 1. It was shown that there are no b.g.i. types of bamboo classified by Grosser and Liese among the bamboo trees on Mt. Jiri (Phyllostachys and Sasa). 2. As for the thickness of the culm wall in the culm, it was shown that the culm wall of the Phyllostachys becomes thinner in proportion to its nearness to the upper part of the tree, but no distinctive difference appeared in the Sasa. 3. The c, d, and e types of Sasa were the same as those of the Phyllostachys, but there was a vascular bundle type of the a' type, which was quite different from that of the Phyllostachys. 4. It was shown that the a', d, and e types of Sasa were distributed in a zone less than 500m above sea level, but no a' type was distributed in the high mountain area except for the c, d and e types which ranged from 600m to 1000m above sea level. Such facts mean that the vascular bundle sheath has changed in quantity because of the height of mountain. 5. In general, as compared with the Phyllostachys, the Sasa (types a, c, d and e which included a new type a) have fewer vascular bundles. 6. Considering the above results, it is thought that not by the current Sasa classification method based on observation of the the study of Sasa form the outside, but by a new method of classification based on the aspect of the physiological construction as seen from the inside wall is advanced. I believe this new method of classification to be a first step towards an epoch-making methodological advance and encourage the further study of it.

• Journal of Chest Surgery
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• v.18 no.3
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• pp.474-481
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• 1985

Pulmonary cavity is the result of necrosis of lung parenchyma with evacuation of the necrotic material via the tracheobronchial tree. A communication with the tracheobronchial tree permits air to enter the area of necrosis, so the radiologic result show the a lucent defect. The radiologic characteristics of the wall of a cavity are determined by the reaction of the lung parenchyma to the pathologic process. Therefore, the shadows of the chest films in cavitary lesion were variable in its nature. The author, in 42 cases which have a cavitary lesion in X-ray findings among 172 cases resected lung obtained in P.N.U.H. from 1979 to June, 1985, studied similarities and differences between the pathogenesis of these lesions and the radiologic findings. The author reviewed the 42 cavitary lesions and the following results were obtained. 1. The cavitary lesions were seen in 42 [24.4%] out of 172 cases of resected lung disease. 2. Histopathologically, pulmonary tuberculosis was 47.6% and primary lung cancer was 9.5%. 3. The most common site of the lesion was right upper lobe. 4. The most common size of the cavity was from 3 to 6 cm in diameter. 5. Lobectomy was the most common operated method.

• ALGAE
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• v.22 no.2
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• pp.57-67
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• 2007

We analyzed the nuclear-encoded large subunit ribosomal RNA gene (LSU rDNA) sequences of 19 dinoflagellates occurring in costal waters off Korea and reconstructed a phylogenetic tree containing 74 representative species from 37 distinct genera. Of these, the LSU rDNA sequences of Amylax triacantha (Jörgensen) Sournia, Gonyaulax verior Sournia (= Amylax diacantha Meunier), Gyrodinium fissum (Levander) Kofoid et Swezy, Katodinium glaucum (Lebour) Lebour III, Noctiluca scintillans (Macartney) Kofoid et Swezy, Oxyphysis oxytoxoides Kofoid, and Pyrophacus steinii (Schiller) Wall et Dale are reported for the first time. Our LSU rDNA tree consistently placed Oxyrrhis marina Dujardin and N. scintillans at the most primitive positions, giving rise to a strongly supported monophyletic group of typical dinoflagellate species belonging to the Dinophyceae. The phylogenetic relationships among the typical dinoflagellates, however, were not resolved in the higher taxonomic levels in general. Only genera at terminal branches were usually supported with high confidence. The Dinophysiales, represented by Dinophysis species and O. oxytoxoides, formed a strongly supported monophyletic assemblage. The Gymnodiniales and Peridiniales were recovered as polyphyletic groupings. Members of the Gonyaulacales were consistently grouped together, but lacked statistical support. Within this order, the Ceratiaceae and Goniodomataceae each formed a monophyletic group, but the Gonyaulacaceae was polyphyletic. The phylogenetic relationships of the Gonyaulacaceae were generally congruent with differences in the combinations of the apical pore complex, hypothecal organization and thecal formula.

• The Korean Journal of Food And Nutrition
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• v.22 no.1
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• pp.97-102
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• 2009

In order to obtain a non-toxic and more active and stable microorganism-produced tyrosinase inhibitor, we isolated actinomycetes F-97, a producer of tyrosinase inhibitor, from soil. The aerial hyphae of this strain were gray in color with tree types. Under the microscopic examination, the isolate formed a spiral aerial spore mass with a smooth surface. The analysis of cell wall acid hydrolysate of the isolate revealed the presence of LL-diaminopimelic acid(LL-DAP). No specific sugar was detected. From these results and the cultural and physiological characteristics described in the Bergey's Manual, actinomycetes F-97 was identificated as, or best-matched to, Streptomyces aburaviensis.

• Journal of the Korean Wood Science and Technology
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• v.22 no.2
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• pp.61-70
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• 1994

This study was executed to find the applicability of press drying of tree disk by investigating the shrinkage and drying defect and to form appropriate model by comparing the actual moisture content(MC) and internal temperature in respect of drying time with calculated values based computer simulation to which was applied finite difference method. In press drying disk, heating period, constant drying rate period maintained plateau temperature at 100$^{\circ}C$ and falling drying rate period were significantly distinguished. Actual MC and internal temperature were analogous to those calculated at comparing points. Heat transfer model formed by Fourier's law using specific heat of moist wood and conduction coefficient considering fractional volume of each element of wood cell wall, bound water, free water and air showed applicability as basic data to developing heat expansion, shrinkage and drying stress during press drying. Also mass transfer model formed by Fick's diffusion law using water vapor diffusion coefficient showed applicability. Longitudinal shrinkage was developed by pressure of hot press and tangential shrinkage was restrained by hygrothermal recovery. The heart check, surface check and ring failure were occurred differently in species, but V-shaped crack didn't develop.

• Journal of Chest Surgery
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• v.14 no.4
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• pp.350-353
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• 1981

The pulmonary sequestration is an uncommon congenital anomaly characterized by the presence of a part of lung tissue which is supplied by an aberrant artery from the aorta or its branch and usually has no communication with the normal bronchial tree. It was first presented by Hubber in 1777 and presented in details by Pryce in 1946. We present a case of extralobar pulmonary sequestration experienced recently with a case of intralobar type experienced in 1962. The patient was 11 year old male with the complaint of chronic productive cough. Serial chest films showed a large cyst with or without the air-fluid level on the posterobasal segment area of the left lower lobe. Bronchography showed no definite communication between the cyst and bronchial tree. On operation, the cystic lesion was supplied by an aberrant artery from the descending thoracic aorta 5 cm above the aortic hiatus and was sited at the posterobasal segment area of the left lower lobe. We performed the sequestrectomy and the sequestration was surrounded by its own pleura, 6.8x3.9x3.2 cm in size, contained the pale brown mucoid secretion in a large cyst and showed the primitive alveolar structure of the wall. The aberrant artery was 1 -5 cm long, 0.3 mm in internal diameter and arterio-sclerotic. We also compared 6 cases of collection, 5 intralobar and 1 extralobar type, presented in Korea.