• Title/Summary/Keyword: Natural period of ground

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The Effects of Vestibular Sensory Stimulation Training on Balance and Gait in the Patients with Stroke (전정감각 자극훈련이 뇌졸중 환자의 균형과 보행에 미치는 영향)

  • Jeong, Hye-Yeon;Choi, Jong-Duk
    • The Journal of Korean Physical Therapy
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    • v.26 no.5
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    • pp.365-371
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    • 2014
  • Purpose: The aim of this study is to examine the effects of training in vestibular sensory stimulation on balance and gait of stroke patients. Methods: Twenty patients were randomly assigned to either the experimental group (n=10) or the control group (n=10). Patients in the experimental group received rotational stimulation training, vertical-horizontal stimulation training, gait training on a flat surface with vestibular sensory stimulation, and gait training on soft ground with vestibular sensory stimulation. Patients in the control group received general treadmill gait training. The intervention was applied four times per week, 25 minutes each time, for a period of four weeks. We measured Berg Balance Scale (BBS), Biodex Balance System, Timed up to Go (TUG) test and Dynamic Gait Index (DGI) to evaluate balance and gait ability. Results: BBS differed significantly in both groups between before and after the intervention (p<0.05) and changes in BBS after the intervention differed between the two groups (p<0.05). According to the Biodex Balance System test result, only the experimental group showed significant changes in balance in the conditions of static eyes open (SEC), dynamic eyes open (DEO), and dynamic eyes closed (DEC) (p<0.05). TUG test results differed significantly between prior to and after the training in both the experimental group and the control group (p<0.05) and changes in TUG after the intervention differed significantly between the two groups (p<0.05). DGI results showed significant change after the intervention in the experimental group only (P<0.05). Conclusion: Training in vestibular sensory stimulation was effective in improving static-dynamic balance and gait ability of stroke patients.

Variations in Catches of Fisheries according to the Climate Change of Korea (우리나라에서 기후 변화에 따른 어업 생산량의 변동)

  • Kim, Jong-Gyu
    • Journal of the Society of Disaster Information
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    • v.18 no.1
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    • pp.194-201
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    • 2022
  • Purpose: This study investigated the relationship between climate factors and the catches in Korean offshore fisheries in recent three decades (1981 to 2010). Method: This study focused on seven types of fish species preferred in Korean cuisine. In the study, 10-year moving averages were used so that long-term trends could be easily identified. Results: Both air temperature and sea surface temperature (SST) on the coast of Korea rose in the period (p < 0.05). The rise in SST was significantly correlated with the rise in air temperature (p < 0.05), but not with precipitation. In the 2010s compared to in the 1981, catches of anchovy and squid greatly increased (p < 0.05), while catches of Alaska / walleye pollock has been almost extinct over the past 30 years. As such, cold-water fish species decreased or disappeared, and their fishing ground was replaced by warm-water fish species. Conclusions: These findings indicate that fish species caught in offshore fisheries of Korea have changed due to climate change, especially warming. This suggests that the warming of the Korean Peninsula may have a significant impact on the supply of fishery products and food security to Koreans in the near future.

Dynamic Analysis for Base Isolated Structure with Shear Keys (쉬어키를 가진 면진건축물의 동적해석)

  • Han, Duck-Jeon;Kim, Tae-Ho
    • Journal of Korean Association for Spatial Structures
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    • v.7 no.1 s.23
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    • pp.45-53
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    • 2007
  • Recently, high-rise base isolated building structures with shear keys are often constructed in Japan which frequently occurs earthquakes. High-rise buildings are less damaged because those buildings have longer natural period than md or low rise buildings. The shear key is device that prevents the base isolators operating by the wind loads not by the earthquake loads. In case of big base shear force acts on the shear keys by earthquake, this device is broken and base isolator is operated. Therefore, seismic intensities play a role in acting on the shear keys. If wind loads are hither than the earthquake loads, the shear keys designed by wind loads are not operated in earthquakes. So, the requirements of shear keys in high-rise base isolated building structures must be examined in Korea with moderate seismic legions. In this study shear keys are applied with 5 and 15 stories base isolated building structures and investigated their dynamic responses to original and 1/2 scale downed El Centre NS(1940) ground motions. The results show that the yield shear forces of the shear keys affect significantly the dynamic behavior of base isolated building structures

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A Study on the Nature observation and Scientific methodology in Zhōuyì周易 - Focusing on its association with Contemporary Science (『주역(周易)』의 자연관찰과 과학적 방법론에 관한 연구 - 『주역(周易)』에 나타난 현대자연과학적 의미를 중심으로 -)

  • Shin, Jungwon
    • (The)Study of the Eastern Classic
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    • no.71
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    • pp.99-128
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    • 2018
  • Zhōuyì周易 is intended to explain the affairs of human beings by observing the images and works of all things in the universe, abstracting them into the $b{\bar{a}}gu{\grave{a}}$八卦, calculating the process and inducing the outcome by the method of stalk divination, in which this paper finds the origin of natural scientific thought of Zhōuyì. The way of Zhōuyì's thought on the natural science is distinguished from that of the Western's. In the West, people dismantled the objects into the parts until they reached the atom and analyzed them by the principle of causality to draw an axiomatic truth. In the meantime Zhōuyì observed and studied the dynamic functions and changes of all things for the convergence of the whole. While the way of Zhōuyì's thinking could have not contributed to the development of modern scientific development, that of the West overwhelmed Asian development passing through the period of enlightenment during 16-17 century. This paper tries to articulate the points where Zhōuyì can share its theory with the contemporary science by finding the traces of scientific thoughts in Zhōuyì. It encounters its ground from the methodology of natural science and scientific statements proposed by Zhōuyì. The essential concepts of Zhōuyì are induced from all things in nature. This can be considered as the idea of '法自然'(emulating the patterns and examples from nature). Also they observed the images and changes seen by the habits of animals, plants and human beings to sense and perceive their laws. These are regarded as the methodology of natural science in Zhōuyì. As a book of divination, the way of stalk divination is designed to calculate the future by using the system of 'numbers'. 'tàijí太極', ' yīnyáng陰陽', 'four symbols四象', '$b{\bar{a}}gu{\grave{a}}$八卦' and 'wǔxíng五行' are the essential concepts of Zhōuyì to represents the dynamic phenomena and changes of the natural order. Among them '$b{\bar{a}}gu{\grave{a}}$八卦' is a presentment to explain the structure of the world not by the individual analysis of things but by the unification of the whole through the contradictions and interchanges among them to reach the new orders. As of now, the studies of Zhōuyì in Korea have focused on the traditional perspectives, such as political and ethical philosophy. Some of recent studies, having interpreted Zhōuyì with scientific inclination have generated controversy 'Can Zhōuyì be a science?', for which scholars have hard time to reach the agreement. This paper tries to find the headwaters of the contemporary natural science by elaborating the methodology of natural science stated in Zhōuyì.

Typical Seismic Intensity Calculation for Each Region Using Site Response Analysis (부지응답해석을 이용한 지역별 대표 진도 산출 연구)

  • Ahn, Jae-Kwang;Son, Su-Won
    • Journal of the Korean GEO-environmental Society
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    • v.21 no.1
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    • pp.5-12
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    • 2020
  • Vibration propagated from seismic sources has damping according to distance and amplification and reduction characteristic in different regions according to topography and geological structure. The vibration propagated from the seismic source to the bedrock is largely affected by the damping according to the separation distance, which can be simply estimated through the damping equation. However, it is important to grasp geological information by location because vibration estimation transmitted to the surface are affected by the natural period of the soil located above the bedrock. Geotechnical investigation data are needed to estimate the seismic intensity based on geological information. If there is no Vs profile, the standard penetration tests are mainly used to determine the soil parameters. The Integrated DB Center of National Geotechnical Information manages the geotechnical survey data performed on the domestic ground, and there is the standard penetration test information of 400,000 holes. In this study, the possibility of quantitation the amplification coefficient for each region was examined to calculated the physical interactive seismic intensity based on geotechnical information. At this time, the shear wave column diagram was generated from the SPT-N value and ground response analysis was performed in the target area. The site coefficients for each zone and the seismic intensity distribution for the seismic motion present a significant difference according to the analysis method and the regional setting.

The Interrelationships between Yield, Transpiration of the Tobacco Plant, and Seasonal Meteorological Factors during the Growing Season I. Interrelationship between Change of Soil Moisture and Transpiration during the Growing Season (연초재배기간중(煙草栽培期間中) 증산량(蒸散量) 및 수량(收量) I. 연초생육기간(煙草生育期間)동안의 증산량변화(蒸散量變化)와 토양수분(土壤水分)과의 상호관계(相互關係))

  • Hong, Soon-Dal;Kim, Jai-Joung;Cho, Seong-Jin;Lee, Yun-Hwan
    • Korean Journal of Soil Science and Fertilizer
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    • v.22 no.3
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    • pp.228-233
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    • 1989
  • Successive changes of transpiration by the tobacco plant during the growing season with pot trial treated with 30cm and 100cm ground water tables were compared with change of soil moisture content in rhizospere of field under natural rainfall conditions. Transpiration from the 41st to the 60th day after transplanting was the highest showing about 50% of total transpiration of whole cultivation period. As the result, soil moisture condition in rhizospere of field was kept insufficiently during the above period. Transpiration by the plant was so remarkably affected by the meteorological environment that the transpiration on rain-cloudy day was one third of that on clear day at middle stage of the growth. Maximum transpiration in a clear day was obtained from 14:00 to 16:00 at the 58th day after transplanting.

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Embryonic Development of Eggs, Larvae and Juveniles of the Hemitripterus villosus (삼세기 Hemitripterus villosus의 산란생태, 난발생 및 자치어의 형태발달)

  • Park, Ae-Jeon;Han, Kyeong-Ho;Lee, Sung-Hoon;Kim, Hui-Jin;Kim, Seung-Yong;Lim, In-Hyeon
    • Korean Journal of Ichthyology
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    • v.26 no.1
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    • pp.34-41
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    • 2014
  • The present study describes the spawning ecology and early morphological development of Hemitripterus villosus. The natural spawning ground consisted of bedrock and pebbles was the intertidal coast at Taean (Chungnam) and its depth was about 5~10 m. Spawning period was mainly from the end of October to December, when the water temperature and salinity were $6.0{\sim}15.8^{\circ}C$ and mean 32.0‰, respectively. There were no difference of the body shape and color between female and male of Hemitripterus villosus, however its reproductive organs showed clear differences. The male had tube shaped genital papilla, which was connected with testis, and the female had seminal recepacle, which was the lower part of oviduct connected with ovary. Genital papilla of male came out of its body at spawning period and then male copulated. After copulation, female stored the sperm in its seminal recepacle and fertilized when it spawned. Fertilized eggs were reached 8 cells stage after fertilization at rearing water temperature $8.2{\sim}14.9^{\circ}C$. At 29 hours after fertilization, it reached morula stage, and at 146 hours after fertilization, its embryo was clearly formated. Hatching was begun from 1,488 hours (62 days) after fertilization with $8.2{\sim}14.9^{\circ}C$ water temperature. The newly hatched larvae were 12.99~15.46mm(mean $14.16{\pm}0.65$ mm) in TL (Total Length), and its mouth and anus were open. At 7 days after hatching, its yolk sac was completely absorbed and the myotomes were 15+25=40, measuring 15.23~15.54mm(mean $15.39{\pm}0.22$ mm, n=5) in TL. At 75~80 days after hatching, it was measured mean $30.06{\pm}0.76$ mm in TL, and it had reached the juvenile stage with the complete set of fin rays.

Ecological Role of Urban Stream and Its Improvement (도시하천의 생태학적 역할과 개선방안)

  • Son, Myoung-Won
    • Journal of the Korean association of regional geographers
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    • v.4 no.1
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    • pp.15-25
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    • 1998
  • A stream plays an important role as the source of drinking water, the ecological space and the living space. But the today's urban stream whose ecosystem is destroyed and water quality become worse in consequence of covering, concrete dyke construction, and the adjustment of high-water-ground[dunchi], is deprived of the function as a stream. Therefore this paper aims to elucidate the role that urban stream plays ecologically and to try to find a improvement to the problem. A stream is the pathway through which several types of the solar radiation energy are transmitted and the place which is always full of life energy. In the periphery of a stream, primary productivity is high and carrying capacity of population is great. Thus ancient cities based on agricultural products grew out of the fertile surroundings of stream. In Korea most cities of the Chosen Dynasty Period based on the agriculture have grown out of the erosional basins where solar energy is concentrated. The role of a stream in this agricultural system is the source of energy and material(water and sediment) and a lifeline. In consequence of the growth of cities and the rapid growing demands of water supply after the Industrial Revolution, a stream has become a more important locational factor of city. However, because cities need the life energy of urban streams no longer, urban streams cannot play role as a lifeline. And As pollutant waste water has poured into urban streams after using external streams' water, urban streams have degraded to the status of a ditch. As the results of the progress of urbanization, the dangerousness of inundation of urban stream increased and its water quality became worse. For the sake of holding back it, local governments constructed concrete dyke, adjusted high-water-ground[dunchi], and covered the channel. But stream ecosystem went to ruin and its water quality became much worse after channelization. These problems of urban stream can be solved by transmitting much energy contained in stream to land ecosystem as like rural stream. We should dissipate most of the energy contained in urban stream by cultivating wetland vegetation from the shore of stream to high-water-ground, and should recover a primitive natural vigorous power by preparation of ecological park.

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A Study of collapsed conditions of the stone pagoda in Mireuk Temple Site (미륵사지석탑 붕괴상태 고찰)

  • Kim, Derk-Moon
    • Korean Journal of Heritage: History & Science
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    • v.38
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    • pp.305-327
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    • 2005
  • Although the stone pagoda in Mireuk Temple site, Iksan, Cholla Province has been collapsed long time ago, few historical record has clearly explained the reason why the pagoda was collapsed and when. The west side of the pagoda have been destroyed from top to the sixth floor and the broken or damaged stone materials have been piled up in disorder. the lower part in the west was reinforced and enclosed by a stone embankment levelled to the height of the first storey of the pagoda. With no record informing the historical fact when it was made and by whom, it is only presumed that the embankment may have been built long time ago in order to prevent remains from further destruction. In the second chapter of the study, it has been tried to restore a reasonable historical background of the pagoda based on records or comments found in literatures such as traditional poetry and essays in chronological order. The collapsed slope in the west side, just above the embankment surrounding the lower part of the pagoda, was concreted in 1915 during the Japanese colonial period. Then in 1998, the Jeollabukdo has examined the structural safety of the pagoda. The Cultural Properties Committee has decided have the concrete layer removed and moreover to take apart the whole pagoda. It is also included that the disassembled stone materials should be given proper conservation treatments before being put into the place where they were in the reassembling process. The front view of the collapsed phase of the pagoda was revealed when the concrete-covered layer was removed. A hypothesis was built that there may be as many different appearances of collapsed pagoda depending on natural causes such as earthquake, sunken foundation, flood and typhoon. In chapter three, characteristic features were classified by examining various images of pagodas destroyed by different natural reasons mentioned in historical records. The chapter four dealt with comparison and analysis on the conditions shown in the stone pagoda in Mireuk Temple site and other examples studied in advance. The result of the study revealed that though having been made higher than the ground surface, the podium or the base of the pagoda actually has been eroded by rain and water. The erosion is supposed not only to have been proceeded for a long time without break but also to have caused the first storey body stone in the west inclined to outward. It has come to a conclusion that the pagoda may have been lead to collapse when the first storey body stone, supporting the whole weight from the upper storeys, became out of upright position and lost its balance. However, no such distinctive features of structural changes shown in pagodas collapsed by natural causes like earthquake, typhoon or sunken basement, have been found in the stone pagoda in Mireuk Temple site.

Nest Characteristics of the Chinese Egret (Egretta europhotes) in South Korea (한국에서 번식하는 노랑부리백로 Egretta europhotes의 둥지 특성)

  • Kang, Jung-Hoon;Kim, In-Kyu;Lee, Hansoo;Kim, Dal-Ho;Rhim, Shin-Jae;Lee, Joon-Woo
    • Korean Journal of Environment and Ecology
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    • v.29 no.6
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    • pp.850-857
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    • 2015
  • This study was aimed to identify the characteristics of nest and breeding site conditions of Chinese Egret (Egretta europhotes) that breed in the uninhabited islets of the western coast of South Korea. It is expected that the information collected through this study can contribute to providing basic information required when building and managing artificial nests in their natural breeding habitats. Chinese Egrets make their nests in the shrub layers of Long Leaf Elaeagnus (Elaeagnus macrophylla), Arrow Bamboo (Pseudosasa japonica), and Baby Brier (Rosa multiflora). A total of 50 breeding nests of Chinese Egret were investigated in June and July 2013, with area-wise distribution as follows: Seomando (11 nests), Hwangseodo (14 nests), Mokdo (10 nests), and Napdaekiseom (15 nests). Vegetation coverage (cover, %), height from the ground to the top (height, cm), thickness from top to bottom of the nest (thickness, cm), reuse period, major axis (cm), minor axis (cm), and depth (cm) of each nest were measured. According to the results of the study on the nest characteristics of 4 breeding groups, the nests in Hwangseodo had the highest coverage, the nests in Mokdo were built in the highest places, the nests in Napdaekiseom showed the longest reuse period, and the nests in Mokdo had the greatest depth. The differences in height and reuse period were significant between Mokdo and Napdaekiseom. Moreover, there were significant differences in reuse period and depth between Seomando and Hwangseodo. There were significant differences in cover, minor axis, and depth between breeding groups that built nests on Arrow Bamboo (Mokdo and Napdaekiseom) and Baby Brier (Seomando and Hwangseodo). Nest characteristics of Chinese Egret were generally similar, while some variables showed different values for different breeding groups.