• Title/Summary/Keyword: Natural change

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Effects of Shading Rate and Method of Inside Air Temperature Change in Greenhouse (차광율 및 차광방법이 온실내부의 온도변화에 미치는 영향)

  • 이석건;이현우;김길동;이종원
    • Journal of Bio-Environment Control
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    • v.10 no.2
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    • pp.80-87
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    • 2001
  • This study was conducted to provide basic data for the design of shading facility of greenhouse. The proper distance between external shading screen and roof surface, transmissivity of shading materials, and shading effects of external and internal shadings were analyzed. About a distance of 10 cm between inclined external shading screen and roof surface was enough to guarantee the external shading effect in the greenhouse without roof vent. The inside temperature of greenhouse installed with 85% internal shading screen was lower the maximum of 4$^{\circ}C$ and mean of 2$^{\circ}C$ than that with 55% internal shading screen in both natural ventilation and no ventilation condition. The difference of soil temperature between shading and no shading greenhouse was great, but the difference by shading rate or shading method was small. The performance of external shading for controlling inside temperature down was superior to that of the internal shading. The externally inclined shading screen parallel to the roof surface of greenhouse was more effective than the externally horizontal shading screen in controlling inside temperature of greenhouse without roof vent.

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Patterns of Waterbirds Abundance and Habitat Use in Rice Fields (논습지에 도래하는 수조류의 서식지 이용과 개체군 특성)

  • Nam, Hyung-Kyu;Choi, Seung-Hye;Choi, Yu-Seong;Yoo, Jeong-Chil
    • Korean Journal of Environmental Agriculture
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    • v.31 no.4
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    • pp.359-367
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    • 2012
  • BACKGROUND: As natural wetlands are decreased by increment of human demand, the importance of rice fields as an alternative habitat for waterbirds is well documented. However, the relationship between waterbirds use and management practice of rice fields has not been fully understood. The present study attempted to understand the changes in temporal abundance of waterbirds and their preference for habitat types in rice fields all year round. METHODS AND RESULTS: Waterbirds census were conducted in rice fields around Asan bay in Korea during April 2009-March 2010 and April 2011-March 2012. In the bird counts, the locations of the observed birds on a 1/2,500 map were recorded along with the local habitat type (paddy, ditch, levee, road). Thirty five species of waterbirds recorded in the rice fields during the survey period and three major groups (shorebirds, herons, and waterfowls) were characterized according to season and micro-habitat use. Shorebirds visited a flooded paddy for feeding during their spring migration season (April-May), and herons used the rice field as feeding sites during their breeding periods (April-October). Most waterfowls were observed in a dry paddy to feed a fallen rice seed and stubs during the winter season (September-March). Waterbird groups selectively used micro-habitats in rice field. Shorebirds and waterfowls mainly preferred at rice paddies, while herons were attracted to most habitat types. CONCLUSION(S): Rice fields supported various waterbirds all year round and waterbird communities using the rice fields were dramatically changed according to seasonal change of rice field condition.

A Case Study of Foraging Time Budget and Habitat Selection of Oriental White Storks (Ciconia boyciana) in Natural State (자연상태에서 황새의 섭식 행동과 서식지 선택에 대한 사례연구)

  • Sung, Ha-Cheol;Cheong, Seok-Wan;Kim, Jung-Hee;Kim, Su-Kyung;Park, Shi-Ryong
    • Korean Journal of Environmental Biology
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    • v.26 no.2
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    • pp.121-127
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    • 2008
  • As a step toward developing conservation and restoration plans for an endangered species of the Oriental White Stork (Ciconia boyciana), we studied daily foraging behavior and ecology. We released two individuals, male and female, after enclosing study site with a fence and cutting out a part of two or three feathers of primaries. Research was conducted from 16 June to 11 July, 2007 for 25 days at Whawonri, Mewonmyung, Chungbuk province. We investigated diural and daily variation of foraging time budget, diet composition, and habitat selection of the feeding individuals. The storks quadratically invested for foraging time and resting time according to time of day, but no significant variation in the foraging time and resting time appeared daily over 25 days. As a result, the storks mainly used wetland as a foraging site in the center of the study area to that in the edge as well as to other types of habitat. The high usage for wetland in the center did not change over the 25 days while Rice field decreased and Wetland in the edge and Pathway increased. Female invested more time for foraging than male, but the foraging efficiency did not differ between them. We discussed the significance of foraging behavior and habitat selection for management plan.

Effects of High-Intensive Exercise Duration on Hematologic Properties and Cytokines in Rats (고강도운동 지속시간이 rat의 혈액학적 조성과 사이토카인에 미치는 영향)

  • Hyun, Kyung-Yae
    • Journal of Life Science
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    • v.21 no.7
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    • pp.1039-1045
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    • 2011
  • The effects of duration and time-dependent, high-intensity exercise on hematological properties and inflammation-related parameters in rats were studied. 20, 60, and 120 min of high-intensive exercise were performed daily for 8 weeks. None of the complete blood count (CBC) factors were affected by the exercise, except for the leukocyte concentration which, in the 20 min group, showed an increase of 47% compared to the control, but this was decreased after 60 min by 30% compared to the control. As exercise was performed for 60 min or longer, serum concentrations of $Fe^{++}$, unsaturated iron biding capacity (UIBC), and total iron biding capacity (TIBC) were significantly elevated in comparison to the control, where 20 min of exercise did not show any change. Both levels of interleukin-6 (IL-6), a pro-inflammatory cytokine, and interleukin-10 (IL-10), an anti-inflammatory cytokine in the serum, were elevated in response to the high-intensity exercise, however the rate of IL-6 increase was higher than the rate of exercise intensity increase, thus the offset of inflammation might be suggested. The concentration of nitric oxide (NO) in the serum became high in response to the exercise. Overall, the current observation suggests that inflammation-like responses to high-intensity exercise might be due to high circulation of blood flow and high oxygen requirement, resulting in systemic damages. However, under the current high-intensity exercise conditions, more than 20 min of exercise might not be suggested for health care purposes.

Genetic Diversity and Population Genetic Structure of Exochorda serratifolia in South Korea (가침박달 집단의 유전다양성 및 유전구조 분석)

  • Hong, Kyung Nak;Lee, Jei Wan;Kang, Jin Taek
    • Journal of Korean Society of Forest Science
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    • v.102 no.1
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    • pp.122-128
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    • 2013
  • Genetic diversity and population genetic structure were estimated in nine natural populations of Exochorda serratifolia in South Korea using ISSR marker system. Average of polymorphic loci per primer was 5.8 (S.D.=2.32) and percentage of polymorphic loci per population was 78.7% with total 35 loci from 6 ISSR primers. In AMOVA, 27.8% of total genetic variation came from genetic difference among populations and 72.2% was resulted from difference among individual trees within populations. Genetic differentiations by Bayesian inference were 0.249 of ${\theta}^{11}$ and 0.227 of $G_{ST}$. Inbreeding coefficient for total populations was 0.412. There was significant correlation between genetic distance and geographic distance among populations. On the results of Bayesian cluster analysis, nine populations were assigned into three groups. The first group included 5 populations, and the second and the third had two populations per group, respectively. These three regions could explain 10.0% of total genetic variation from hierarchical AMOVA, and the levels of among-population and among-individual were explained 19.7% and 70.3%, respectively. The geographic distribution of populations following the three Bayesian clusters could be explained with mountain range as Baekdudaegan which is the main chain of mountains in Korea. The mountains as the physical barrier might hamper gene flow in the pearlbush. So when protected areas are designated for conservation of this species, we should consider those three regions into considerations and would better to choose at least one population per region.

A Study on the Reinforcement Effect Analysis of Aging Agricultural Reservoir using Surface Stabilizer (표층안정재를 사용한 노후 농업용 저수지의 보강효과 분석에 관한 연구)

  • Kim, Jae-Hong;Kim, You-Seong;Cho, Dae-sung
    • Journal of the Korean Geosynthetics Society
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    • v.19 no.2
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    • pp.13-21
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    • 2020
  • In Korea, small reservoirs have been constructed for the supply of agricultural water, but most of them have been over 50 years from the year of construction. Aging agricultural reservoirs are being investigated for serious defects such as leaks and movements in slope, which are very vulnerable to safety. Accordingly, grouting methods are used to reinforce aging agricultural reservoirs in Korea. However, cement used as a grouting injection material consumes natural resources and generates a large amount of greenhouse gases during production. In addition, there is a problem that sufficient reinforcement is not made due to various factors such as the injection amount, the compounding ratio, the injection pressure, and etc. Therefore, due to these problems, the development of new materials and methods that can replace the grouting method and cement is required. In order to solve these problems, this study conducted an laboratory test on the surface stabilizer used to secure the stability of road and rail slopes. In addition, the program was analyzed and the reinforcing effect was examined when the surface stabilizer was used as reinforcement material for aging agricultural reservoir. As a result of the laboratory test, when the surface stabilizer is mixed, the increase of cohesion is possible up to 9% and there is no change in the friction angle. The results of the program analysis showed that the 1.0m reinforcement of slopes increased the factor of safety by 1.4 times, making it possible to reinforce the aging agricultural reservoir using surface stabilizers. And as a reinforcement method, it was analyzed that it is most appropriate to reinforce the slope and the bottom of slope simultaneously.

A Consideration of Look Reflecting Time in Fashion (패션에 있어서 시간성이 반영된 룩에 관한 고찰)

  • Joo Mi-Young;Kim Young-In
    • Journal of the Korean Society of Costume
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    • v.56 no.6 s.105
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    • pp.1-15
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    • 2006
  • The purpose of this study is to present a new viewpoint in look by closely examining fashion and look through the past, present, and future. Specifically, the concept of time is studied and fashion is considered based upon the concept of time, finally, looks in fashion related to time are analysed. For this study, the literature of retro, modern, contemporary, futuristic looks that express the past, present, and future, and the classic look, the popularity of which transcends the concept of time was considered focusing on 20th century women's fashion. Design characteristics of these looks were analyzed utilizing photographs of collection images. The results of the study are as follows: first, although the retro look of different periods regularly rotate and appear, they change and develop in new and various ways depending on the Periodic background of the time they appear in, and thus show simultaneously the cyclical and straight nature of time. Second, the modern look includes not only the moaning of time concept of the present, but also of interpreting anew the formal significance of modernism in the present. In other words, because it cyclically repeats the times of past modern periods, the look can be said to focus on the cyclical nature of time. Third, the contemporary look is a style that expresses current time most exactly as it exists, and it can be said to be the look in which current time is most vividly expressed. Fourth, the time concept in futuristic look is a subjective time that selectively accommodates and expresses the objective time of the future which has not yet come, and that can be the look's most important point. Last, the classic look possesses an objective value that transcends the concept of time, and it keeps returning, showing the cyclical nature of time. The closer this study came to the present, it could be seen that a look communicated more complex meanings, Influenced by periodic phases such as diversification, individualization, and eclecticism, and that while it could not be defined as any one look, various elements were expressed eclectically by being mixed and matched with each other, and it could utilize more natural forms, colors, and materials.

Viewing afar of Nature and Aesthetic Character in Sijo (시조(時調)에 나타난 산수자연(山水自然)의 원망(遠望)과 그 미적(美的) 성격(性格))

  • Choi, Dong-Kook
    • Sijohaknonchong
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    • v.30
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    • pp.9-20
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    • 2009
  • The purpose of this study is to consider factors such as one's sight of viewing afar, expressional principles, and basic aesthetic category, which are treated importantly by the poets of the Joseon Dynasty era in appreciating nature. 'Afar' of the viewing afar is actual distance and aesthetic distance at the same time. Viewing afar is to find geographical features, depth, and details of a mountain, seeing the whole nature at a high place. Also, it can make possible escape from the external limitation of nature and get mental superiority and enhancement. Ultimately, viewing afar is to find out everlasting change of the nature and reason of natural creation. One's sight in viewing afar makes an appreciator's mind empty and calm, and it makes chance to harmonize human with nature. Viewing afar is to unite human nature to naturality beyond realistic value, idea, and artificiality. The mind from viewing afar has peacefulness and it is a state of serenity without any secular atmosphere. Viewing afar is an eye for beauty to leap toward an endless free state from narrow sight about objects. It rejects modification and technics in achieving an world of harmony. It means that objects should not be restrained by human's recognition. There are three expressions, which are high, horizontal, and transcendental viewing afar. The aesthetic category and beauty of peaceful mental state are realized by the expressions. The peaceful mental state makes peaceful mind from realistic conflicts and makes us experience a profound reason of nature.

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A Study on resource plants around the provincial park in Mt. Unmun(Cheongdo-gun, Gyeongsangbuk-do) (운문산(경북 청도) 군립공원 일대의 자원식물상 연구)

  • Park, Seon-Joo;Song, Im-Geun;Park, Seong-Jun;Lee, Won-Hyoung;Jang, Soon-Young;An, Bo-Ram
    • Korean Journal of Plant Resources
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    • v.23 no.4
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    • pp.327-349
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    • 2010
  • This study was carried out to investigate the distribution of vascular plants and their use from 2007 to 2009 in Mt. Unmum(Cheongdo-gun, Gyeongsangbuk-Do). The vascular plants were summarized as 605 taxa including 98 families, 304 genus, 514 species, 3 subspecies, 68 varieties, and 20 forma. Among the investigated 605 taxa, 21 rare and endangered plants, 29 Korean endemic plants were included. Based on the list of specially designated plants by Ministry of Environment, 70 taxa included Iris odaesanensis and Gastrodia elata were recorded in the investigated area. The naturalized plants were identified as 23 taxa and the percent of naturalized index(NI) was 3.8% of total 605 taxa vascular plants. Usage of 605 taxa were consists of 225 taxa(37.2%) of edible plants, 191 taxa(31.6%) of medicinal plants, 64 taxa(10.6%) of ornamental plants, 46 taxa(7.6%) of pasture plants, 18 taxa(3.0%) of timber plants, 14 taxa(2.3%) of fiber plants, and 3 taxa(0.5%) of industrial plants. To management of natural resource, we suppose that it is required to establish an ecological learning area to minimize human disturbance and an effective managemet strategy by continuous monitoring for ecosystem change.

Covering Types and Covering Ratio Changes of Planted Species on an Extensive Green Roof (관리조방형 옥상녹화 식재식물의 피복률 변화 및 피복유형)

  • Jang, Ha-Kyung;Lee, Eun-Heui
    • Korean Journal of Environment and Ecology
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    • v.25 no.3
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    • pp.404-411
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    • 2011
  • The purpose of this study was to analyze the characteristics of plant covering in the extensive green roof site. Eighteen herbaceous perennial grass such as Caryopteris incara and sedum species such as Sedum Kamtschaticum were planted on an experimental green roof with 10cm substrate depth in 2007. This study investigated vegetation change over 3 growing seasons 2007-2009. The covering rates of planted species mostly increased in 2008, but declined in 2009 except 6 species such as sedum specis and Thymus quinquecostatus var. japonica etc. There were four categories of covering characteristics generated from the results of this study. These include the type of sustain planting site, the type of encroach adjacent site, the type of creeps and spreads, and the type of scatters and spreads. The covering models of eight planted species were drawn by simple regression analysis. However more monitoring of various plants will be needed to establish the information for sustainable roof planting plan.