• Title/Summary/Keyword: 온난기

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지구온난화의 원인과 대책

  • 정진택
    • Journal of the KSME
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    • v.44 no.7
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    • pp.14-17
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    • 2004
  • 지난달부터 상영 중인 영화 ‘Tomorrow(원제 : The Day After Tomorrow)’ 는 이상기후라는 색다른 주제를 다루고 있다. 기상 이변으로 지구 북반구 전체에 빙하기가 시작되어 인류가 최악의 위기를 접하게 된다는 설정의 블록버스터 재난 영화이다. 이상기후현상과 관련하여 가장 심각하게 인식되고 있는 것이 바로 지구온난화일 것이다. 지구온난화라는 말이 학술적으로 사용되기 시작한 지 그리 오래되지 않았음에도 불구하고 현재 대부분의 사람들이 이 용어에 친숙해 있는 것은 그만큼 이러한 지구온난화현상의 심각성에 대해 폭넓게 이해하고 있다는 것을 의미할 것이다.(중략)

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Effects of Gas Velocity and Temperature on $CO_2$ Reaction Characteristics using Dry Sorbent $NaHCO_3$ in Fluidized Bed Reactor (유동층 반응기에서 건식 sorbent $NaHCO_3$를 이용한 $CO_2$ 흡수반응에 미치는 유속과 온도의 영향)

  • 유영우;이봉희;홍선욱;조성호;이창근
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2003.05a
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    • pp.667-672
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    • 2003
  • 화석연료의 연소로 생성되는 $CO_2$는 지구온난화의 주범으로, 대부분 화력발전 등 에너지 산업에서 발생되는 배가스로 대기 중에 방출되고 있으며, 많은 나라들이 규제를 정하고 있다. 우리나라도 선진국과 같이 2008년부터 자발적 의무를 부담할 것을 요구하는 등 국제적인 요구가 증대되고 있다.(중략)

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A Study on the Erosion and Sedimentation Traces According to the Sea Level Changes Since the Medieval Warm Period in the Hwaseong Coast (화성 연안의 중세온난기 이후 해수면 변동에 연동된 침식·퇴적 흔적 연구)

  • Yang, Dong-Yoon;Han, Min;Kim, Jin Cheul;Park, Sujeong;Lim, Jaesoo
    • Journal of The Geomorphological Association of Korea
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    • v.26 no.2
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    • pp.39-54
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    • 2019
  • In this paper, based on evidence of coastal sediment, we show that erosion and sedimentation environments are very sensitive to sea level changes during the Medieval Warm Period (MWP) and the Little Ice Age (LIA). We identified four sedimentary units(4.57-3.07m), which formed in the Dark Age Cool Period (DACP), MWP and LIA were classified based on the lithostratigraphy, grain size distribution, magnetic susceptibility and geochemistry of a drilling core taken from the west coast of Hwaseong City. The unconformity surfaces as boundaries of the units were also identified by the lithostratigraphy shown on the drilling core. We propoese that sedimentation was dominant in the area during the periods of sea level rise, whereas erosion prevailed during the periods of sea level fall. Particularly, extreme events, such as floods and typhoons are believed to have accelerated these processes, and we found the associated evidence in sediments of two units. This study provides an example of estimating the relative sea level variation using coastal sediments and may be useful for studying past sea level changes around the Korean Peninsula.

Impacts of Climate Change and Follow-up Cropping Season Shift on Growing Period and Temperature in Different Rice Maturity Types (미래 기후변화 및 그에 따른 재배시기 조정이 벼 생태형별 생육기간과 생육온도에 미치는 영향)

  • Lee, Chung-Kuen;Kwak, Kang-Su;Kim, Jun-Hwan;Son, Ji-Young;Yang, Won-Ha
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.56 no.3
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    • pp.233-243
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    • 2011
  • This experiment was conducted to investigate the effect of future climate change on growing period and temperature in different rice maturity types as global warming progressed, where Odaebyeo, Hwaseongbyeo, Ilpumbyeo were used as a representative cultivar of early, medium, and medium-late rice maturity type, respectively, and A1B scenario was applied to weather data for future climate change at 57 sites in Korea. When cropping season was not adjusted to climate change, entire growing period and growing temperature were shorten and risen, respectively, as global warming progressed. On the other side, when cropping season was adjusted to climate change, growing period and temperature after heading date were not changed in contrast to growing period and growing temperature before heading which were more seriously shortened and risen as global warming progressed than in not adjusted cropping season. It is supposed that adjusting cropping season to climate change can alleviate rice yield reduction and quality deterioration to some degree by improving growing temperature condition during grain-filling period, but also still have a limit such as seriously shortened growing period indicating that there need to develope actively new rice cultivation methods and varieties for future climate change.

Present Distribution of Cryophilous Plants and Palaeoenvironment in the Korean Peninsula (한반도 한지선호식물의 분포와 고환경)

  • Kong, Woo-seok
    • The Korean Journal of Quaternary Research
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    • v.5 no.1
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    • pp.1-13
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    • 1991
  • The distribution of cryophilous arctic-alpine and alpine plants in Korea is reviewed in connection with palaeoenvironment, along with a discussion to their origins, patterns of migration, and their refugia. At present, the estimated number of Korean arctic-alpine and alpine species is 419, and this includes 75 arctic-alpine species, 239 alpine species and 105 Korean endemic alpine species. The disjunctive distribution of cryophilous arctic-alpine and alpine plants is likely to be due to first, the downslope and southward expansion of those species towards the Korean peninsula as a primary refugia from the arctic region as the Pleistocene glacial phases approached, and then their subsequent isolation upslope in mountain areas toward a secondary refugia as the interglacial and post-glacial climatic ameliorations followed; secondly, the expansion of forest tree communities on lowland and montane areas subsequent to the end of the Pleistocene has had the effect of dividing formerly high mountains as a result of the increased competition; and thirdly, the general disapperance or restriction of available habitats for arctic-alpine and alpine species because of post-glacial climatic amelioration. The existence of 139 alpine species exclusively in the north of Korea may be due to the following reasons; first, frequent exchanges of alpine floras with other neighbouring East Asian regions would have been facilitated; secondly, there are numerous high mountains available for the alpine plants to survive and prosper during the post-glacial period; thirdly, the existence of easy accesses between mountains within the north, which has enabled alpine floras to migrate when necessary; and finally, the availability of diverse environments and habitats for the alpine flora of the north. However, the continued survival of those species in Korea at the world's or East Asia's southernmost limits of their distribution for many species is in danger if global warming associated with the greenhouse effect takes place.

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The Vegetational and Environmental History of the Pre-Holocene Period in the Korean Peninsula (한반도 식생 및 환경변천사(홀로세 이전 시대를 중심으로))

  • Kong, Woo-Seok
    • The Korean Journal of Quaternary Research
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    • v.6 no.1
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    • pp.1-11
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    • 1992
  • The reconstruction of the vegetational and environmental history of the Korean peninsula by the use of various fossil floral data from the Carboniferous period to the Pre-Holocene is reviewed. Though the oldest plant fossil in Korea (Neuropteris) dates back to the Carboniferous period, the first appearance of many of the present-day floristic genera indeed dates back to the Oligocene (c. 40 to 20 million years B.P.), and includes many thermophilous genera. The presence of thermophilous genera in the Oligocene at up to four degrees north of their present distributional limits implies that the climate of the Oligocene was warmer than that of today. The occurrence of similar thermophilous floristic element at up to six degrees north of their present range during the Middle Miocene suggests a maximum northward expansion of warmth-loving evergreen broadleaved vegetation for, recent Korean vegetation history. The continued occurrence of numerous present-day genera since the Oligocene period indicates a long-term stability of Korean vegetation, along with minor fluctuations within it. The admixture of evergreen coniferous plants and deciduous breadleaved plants, however, indicates a probable temperate climate for much of the Middle Pleistocene. There are couple of evidences which are indicative of an early-stage anthropogenic disturbance of natural vegetation during the Middle Pleistocene of Korea. The presence of cold-episodes during the Upper Pleistocene caused a general expansion of deciduous plants and cryophilous evergreen coniferous, plants. It is likely that the maximum southward expansion of cryophilous arctic-alpine and alpine floras in Korea occured during the penultimate glacial period. The disappearance of some cryophilous genera from 10,000 years B.P. marks the continued climatic amelioration since then, along with minor climatic fluctuations during the Holocene period.

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Holocene climate characteristics in Korean Peninsula with the special reference to sea level changes (해수면 변동으로 본 한반도 홀로세(Holocene) 기후변화)

  • Hwang, Sangill;Yoon, Soon-Ock
    • Journal of The Geomorphological Association of Korea
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    • v.18 no.4
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    • pp.235-246
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    • 2011
  • Sea level fluctuations during the Holocene reconstructed by the results of age dating, microfossils researches and sedimentary facies from coastal alluvial plains contain the valuable informations on climatic changes. The sea level during 'maximum phase of transgression' during 6,000~5,000 yr BP was slightly higher than the present by approximately 0.8~1.0 m and the summer temperature conditions seemed to be higher than those of the present by 2~3℃ in the Central Europe when the period of 'Climatic Optimum' might be dominant. The sea level in Korean Peninsula was assumed by 0.8~1.0 m higher at that time compared to the present and climate seemed to be warmer. At 2,000~1,800 yr BP in Korean Peninsula, the sea level reached the higher stand than the present by approximately 1.1~1.3 m and the climatic conditions might be warm similar to the period of 'Climatic Optimum'. Although the temperature in the Central Europe during the period of 'Subboreal' was about 2~3℃ cooler, it is supposed that the sea level in Korean Peninsula was relatively higher than the present. The sea level at 2,300 yr BP might be similar to that of the present, which was the lowest level since the mid-Holocene. From the fact, climatic environment during the cold period might not be reflected exactly in the sea level.

Phytogeographic study on the Holocene hypsithermal relict plant populations in the Korean peninsula (한반도 홀로세 기후최적기 잔존집단의 식물지리학적 연구)

  • Kim, Jin-Seok;Chung, Jae-Min;Kim, Sun-Yu;Kim, Jung-Hyun;Lee, Byoung-Yoon
    • Korean Journal of Plant Taxonomy
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    • v.44 no.3
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    • pp.208-221
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    • 2014
  • The Holocene Hypsithermal Interval(or climatic optimum) was the warmest post-glacial period: temperatures rose to as much as $1-4^{\circ}C$ above present temperatures. We hypothesize that southern plants expanded northward and upward during the Hypsithermal Interval. The Hypsithermal relict populations are defined as populations which distribute mainly in Is. Cheju and Southern subregions and have populations of short-distance dispersion separated by more than 100 km from the nearest distribution. The Hypsithermal relict species were identified and their distributions were mapped based on botanical floras and checklist, herbaria specimens, ecological studies, and field surveys of selected species. Evaluation of the hypothesis was based on reviews of published pollen stratigraphic and paleoecological studies. The results showed that the Holocene Hypsithermal relicts such as Corylopsis coreana Uyeki, Carpinus turczaninowii Hance, Stewartia koreana Nakai ex Rehder were expanded northward during the Holocene Hypsithermal Interval.

Pollen Analysis form the Holocene Fluvial Deposits of the Jangdaedong Yuseong (대전시 유성구 장대지역 홀로세 하성 퇴적층에서 산출된 화분분석)

  • 윤혜수
    • The Korean Journal of Quaternary Research
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    • v.12 no.1
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    • pp.99-109
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    • 1998
  • 유성구 장대동 지역의 홀로세 하성퇴적층에서 보존 상태가 양호한 화분, 포자가 풍 부하게 산출되었다. 이들 미화석산출을 근거로하여 두 개의 화부대가 설정되었다. 제 I 화분 대는 낙엽성활엽수의 목본화분이 풍부하게 산출괴며 반면에 초본화분은 상대적으로 빈약한 상태로 산출되는 것이 특징이다. 제 II화분대는 초본화분 중 벼과(재배종)화분이 우점으로 산출되며 소나무속도 비교적 풍부하게 산출되는 반면 낙엽성활엽수의 목본화분은 빈약하게 산출되는 것이 특징이다. 시대설정은 인접한 지역에서 화분분석과 함께 절대연령측정이 수 행된 기존의 연구자료와 비교하여 이루어졌다. 따라서 제 I화분대는 1,500 year B.P 이전 제 II화분대는 1,500 year B.P∼현재를 나타낸다. 제 I화분대에서는 인간간섭의 영향을 받기 전 인 자연식생관계를 나타내지만 제 II화분대에서는 농경과 벌목이 본격적으로 시작된 시기로 나타났다, 기후조건은 제 I화분대 동안은 온난한 온대의 습한 환경이었고, 제 Ii화분대 동안 은 현재와 비슷한 한랭한 온대의 습한 환경이었던 것으로 판단된다, 인간의 정착과 농경생 활의 시기에 대한 해석에 있어서 화분분석자료와 고고학자료가 서로 잘 일치하는 것으로 본 연구에서는 나타났다.

10kW Charger consist of Grid-connected inverter and 2-stage DC-DC converter for EV (계통연계인버터와 2단 DC-DC 컨버터로 구성한 전기자동차용 10kW급 충전기)

  • Kim, Kyeong-Tae;Jeong, Jong-Kyou;Chu, Kyeong-Ho;Park, Seung-Hui;Seo, An-Sik;Lee, Seul-Gi;Lee, Jun-Young
    • Proceedings of the KIPE Conference
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    • 2011.07a
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    • pp.553-554
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    • 2011
  • 환경오염의 의한 지구온난화가 세계적 이슈가 되고 있으며 화석연료의 고갈 등으로 기존의 자동차들이 점점 설 자리를 잃어 가는 게 현재 상황이다. 따라서 화석연료 자동차를 대체해야하는 많은 새로운 형태의 자동차가 제시 되고 있는데 그중에 현재 가장 경쟁력과 경제성을 가진 전기자동차가 대두되고 있는 시점에 이를 충전하기 위한 여러 장치들이 나오고 있다. 그중에 우리는 3상계통 인버터와 고효율 DC-DC 컨버터로 구성 된 충전기를 소개하고자한다.

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