• The Journal of the Acoustical Society of Korea
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• v.15 no.2
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• pp.33-39
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• 1996

A theoretical study of the forced vibration response of a cantilevered beam with non-linear dry friction damping is analyzed by various slip displacements and force levels for the position coordinates of spring-mass-damper and external exciting force. A component mode analysis is carried out based on the constraint conditions and Lagrange multipliers to treat physical systems with non-linear damping. The analysis has shown that the basic phenomena observed for a simply supported beam with a dry friction damper attached are also observed for cantilevered beam.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2008.04a
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• pp.364-369
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• 2008

The public facilities are essential of resident life, the public facilities affect quality of life. The purpose of this study is to analyze the present condition of social welfare service and local cultural welfare program of public facilities complex in Seoul. To achieve these study, www.oklife.go.kr is used for data. The results of this study are showed as followings : First, most of the public facilities' program are composed of educational program and program for middle-age. Second, most of the program for infant and elderly age are composed of welfare program and most of the program for teenager, young people and middle age are composed of educational program.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2002.11a
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• pp.223-228
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• 2002

This study is a preference reversal about a policeman image and evaluation by roadside higher stories meeting dwelling pot to the center, and it is an examination, the thing that it analyzed by proposals. Preference anger Was high, and as for the results, the pot which I gave, and bronze was mixed, and formed the skyline with a change appeared with a height and a form of reveal a cross section in meeting dwelling pot star preference evaluation results cluster older brother contrariety. Also, it was arranged the parallel that older brother was parallel in the printing which was monotonous if I wore 1, and the pot that time a little shielding anger was high was evaluated because preference anger was low. Therefore, consideration about a the number of layers interval change must be in order a higher stories meeting dwelling pot reduces that I go for a closing of crossways in the future, and to be able to feel variety with a form enemy.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 2005.11a
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• pp.311-314
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• 2005

Our city structure is being complicated from the development of industry and the increase in population. It makes the ground space overcrowded, so underground space is systematized for use. Because this underground space has very complicated configuration, people have difficulty in finding the route in the underground space. Therefore It is demanded to comprehend configuration of the various space structure, predict pattern of the moving and analyze induction factor of the moving. When people are in the conflagration or dangerous situation, they are in the habit of using the route which they are used to go to and from. It is needed to analyze moving pattern of the pedestrian who usually use the underground space for the sake of dealing with conflagration in the underground space. Finally, this study suggested that general characteristic, distribution, moving route of the pedestrian and factors influencing that they choose the route which the research finds out.

• Journal of Navigation and Port Research
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• v.33 no.4
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• pp.289-294
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• 2009

The living performances of crews and passengers in cabins have been less received attention, while Korea is a top leading country in ship building industry. To develop a high value added ships like 5-star cruisers, researches on the comfort and productivity in cabins should be carried out with urgent. The purpose of this study is to measure and analyze of the ship's indoor thermal conditions in spring, summer and winter, and also to compare the seasonal differences, of which conditions are supplied from and controlled by marine HVAC The temperature, humidity and air supply volume of 5 different needs of cabins on a training ship were measured through a year, which was launched at Dec. 2005 and totally 246 crews can go on board for education. The following results were obtained: (1)In the spring, the temperature in cabins was measured as $20{\sim}25^{\circ}C$ and humidity was below 30%. (2)In the summer, the temperatures was controlled at $21{\sim}27^{\circ}C$ in almost cabins and humidity was between $40{\sim}60%$ which is known as comfort conditions. (3)In the winter, temperature and humidity was maintained between $19{\sim}26^{\circ}C$, and humidity was between $10{\sim}50%$. (4)It is clear that the humidity conditions in cabins are not properly controlled at all through a year to satisfy the Comfort Standards provided by ASHRAE and/or ISO, In conclusion, humidification and dehumidification of cabins must be treated with importance for more comfort living and working environments for crews and passengers.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10a
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• pp.114-115
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• 2000

Aralia elata is found in mountain areas all over Korean peninsula. Aralia elata is the scientific name for Japanese angelica tree. The tree belongs to the family Araliaceae, commonly known as ginseng family. Bud sprouts from apical shoot tip of the plants are rich in flavor and thus mainly used for both folk medicine and vegetable. The stalks with apical buds are gathered in the early spring and planted in sandy soil or water in the greenhouse. The sprouting buds are then collected and sold as fresh vegetable. Although the plants have been used for food, they have been cultivated in a very small scale. In spring, local farmers just go around mountain areas to search the trees and gather the stalks as much as they get and sell them to the market. No conservation efforts have been made to stop the exploitation or to save the dwindling population. We tried to provide local farmers with the plants that may be used as an alternative to stalks from wild populations. This will bel! p conserve the wild populations. However, it is hard to propagate them either by conventional cuttings or by seed germination in a short period of time. Mass propagation using tissue culture systems have shown a great promise with several woody plants. Recently we developed a mass propagation technique via somatic embryogenesis system using mature and/or juvenile explants for Aralia elata. Several factors affecting somatic embryogenesis system including SE(somatic embryo) induction, embryogenic callus proliferation, SE germination, plant regeneration and transplanting to field frill be presented. And some problems arising for the somatic embryogenesis system will be also discussed.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10b
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• pp.16-17
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• 2000

Aralia elata is found in mountain areas all over Korean peninsula. Aralia elata is the scientific name for Japanese angelica tree. The tree belongs to the family Araliaceae, commonly known as ginseng family. Bud sprouts from apical shoot tip of the plants are rich in flavor and thus mainly used for both folk medicine and vegetable. The stalks with apical buds are gathered in the early spring and planted in sandy soil or water in the greenhouse. The sprouting buds are then collected and sold as fresh vegetable. Although the plants have been used for food, they have been cultivated in a very small scale. In spring, local farmers just go around mountain areas to search the trees and gather the stalks as much as they get and sell them to the market. No conservation efforts have been made to stop the exploitation or to save the dwindling population. We tried to provide local farmers with the plants that may be used as an alternative to stalks from wild populations. This will hel! p conserve the wild populations. However, it is hard to propagate them either by conventional cuttings or by seed germination in a short period of time. Mass propagation using tissue culture systems have shown a great promise with several woody plants. Recently we developed a mass propagation technique via somatic embryogenesis system using mature and/ or juvenile explants for Aralia elata. Several factors affecting somatic embryogenesis system including SE(somatic embryo) induction, embryogenic callus proliferation, SE germination, plant regeneration and transplanting to field will be presented. And some problems arising for the somatic embryogenesis system will be also discussed.lso discussed.

• Journal of the Speleological Society of Korea
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• no.84
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• pp.10-21
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• 2008

In order to accumulate the basic informations to assess the scientific and natural values of the Hoe-ok Cave located in Mountain Chi-ak, Seong-nam 2 ri, sin-rim myeon, the natural environments in the cave were investigated from November 2004 to June 2005. The results are as follows; The average temperature in the cave was 2.5$^{\circ}C$ in the winter, 5.5$^{\circ}C$ in the spring, 6.8$^{\circ}C$ in the summer. The average humidity in the cave was 82.5％ in the winter, 86.0％ in the spring, 86.0 in the summer. this results show that the temperature was 10$^{\circ}C$ lower, and the humidity was 4$\sim$10％ lower than those in the Go-su Cave. Inside of the Heo-og Cave, the damages from the garbages and smoke stains by the reckless civilians are expanding. It is necessary to execute the research on the geological facts of the cave and the reassessment on its values in the natural history.

• Journal of Forest and Environmental Science
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• v.38 no.4
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• pp.219-228
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• 2022

This study examined the relationship between the number of forest fires and days with no rainfall based on the national forest fire statistics data of the Korea Forest Service and meteorological data from the Open MET Data Portal of the Korea Meteorological Administration (KMA; data.kma.go.kr) for the last 30 years (1991-2021). As for the trend in precipitation amount and non-rainfall days, the rainfall and the days with rainfall decreased in 2010 compared to those in 1990s. In terms of the number of forest fires that occurred in February-May accounted for 75% of the total number of forest fires, followed by 29% in April and 25% in March. In 2000s, the total number of forest fires was 5,226, indicating the highest forest fire activity. To analyze the relationship between regional distribution of non-rainfall periods (days) and number of forest fires, the non-rainfall period was categorized into five groups (0 days, 1-10 days, 11-20 days, 21-30 days, and 31 days or longer). During the spring fire danger season, the number of forest fires was the largest when the non-rainfall period was 11-20 days; during the autumn fire precaution period, the number of forest fires was the largest when the non-rainfall period was 1-10 days, 11-20 days, and 21-30 days, showing differences in the duration of forest fire occurrence by region. The 30-year trend indicated that large forest fires occurred only between February and May, and in terms of the relationship with the non-rainfall period groups, large fires occurred when the non-rainfall period was 1-10 days. This signifies that in spring season, the dry period continued throughout the country, indicating that even a short duration of consecutive non-rainfall days poses a high risk of large forest fires.

• Korean Journal of Ichthyology
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• v.3 no.1
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• pp.24-35
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• 1991

Fish larvae were collected monthly from coastal water around Hamduck, northern part of Cheju Island from April 1989 to March 1990. During the study period, a total of sixty four species, representing 35 genera and 27 families, were observed, of these 4 species appeared to be major groups which comprised about 66% of total fish larvae abundance, including Ammodytes personatus (February-March), Scomber japonicus(September-March), Enneapterygius etheostomus(June-September), and Engraulis japonica(August-November). Seasonally, the maximun numbers of species and individuals appeared in summer and in spring, and in summer, respectively, while the minima numbers of species and individuals appeared in winter. Inshore species were composed of 44 species(62.9%) and 557 individuals(70.4%), which were much higher both in the species numbers and individuals than those of offshore species.