• Title/Summary/Keyword: Cold Season

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On the Etymology and Definition of Changma (장마의 어원과 정의에 대하여)

  • Ryoo, Sang-Boom
    • Atmosphere
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    • v.11 no.2
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    • pp.6-12
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    • 2001
  • The East Asian monsoon is generally accompanied with the quasi-stationary front along the northern and northwestern periphery of the subtropical anticyclone in the boundary zone of the polar cold air mass and the tropical warm air mass. The rainy season in Korea has been called as Changma since the middle of 1500s. In meteorology, the rainy season with the quasi-stationary front, the Changma front, during the early summer has been defined as the Changma since 1905. The difference of meaning on Changma between meteorologists and the general public sometime does give a confusion. For example, the heavy rainfall event after the retreat of Changma is recognized as Changma by the general public, but not by most of meteorologists. The decision of the onset and retreat dates of Changma among the meteorologists is also ambiguous because of different viewpoints on the definition of Changma. In this study we survey the etymology and definition of Changma.

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Operational Strategy of Anaerobic Digesters Considering Energy Balance (에너지수지를 고려한 혐기성소화시설의 운영방안)

  • Hong, Seong-Gu;Kwun, Soon-Kuk
    • Journal of The Korean Society of Agricultural Engineers
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    • v.50 no.4
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    • pp.59-66
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    • 2008
  • Anaerobic digestion system is getting more attractive in that it produces biogas in the process of organic waste stabilization. Net energy production is important when biogas production is concerned. In this study, net energy production was evaluated with respect to biogas production and heat losses in a hypothetical digester. Under the condition of digester operation with slurry inflow of 5% of TS, additional fuel is required to maintain digester temperature during the winder season. Substrate therefore, needs to have higher VS contents through co-digestion of silage or food waste that has greater values of methane production rate. Heating input slurry is important in cold season, which covers over 80% of heating requirement. Heat recovery from digestate is valuable to reduce the use of biogas for heating. It seems desirable to minimize slurry inflow when temperature is very low. Psychrophilic digestion may be a feasible option for reducing heating requirement.

Variation of the Insolation by Cloud Cover over Pusan in Korea (釜山地方의 雲量에 따른 日射量의 變化)

  • Cho, Byoung-Gil;Lee, Bu-Yong;Moon, Sung-Euii
    • Journal of Environmental Science International
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    • v.4 no.1
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    • pp.13-18
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    • 1995
  • In order to examine the effect on the insolation of cloud cover, we analyzed the data of the insolation, cloud cover and surface air pressure in Pusan during the period of 1991. 10 - 1993.1. At first, we investigate the atmospheric transmissivity A(t) using the Beer's law at clear skies. The atmospheric transmissivity is characterized by cold season high and warn season low. From this atmospheric transmissivity, the empirical formula that shows the variation of the insolation due to the cloud cover is obtained. The result formula is I : l0 A(tn)·( 0.7-0.05×m ). 1 is the insolation that reaches the surface when cloud cover is m and to is solar constant. Although the result is some rough it seems meaningful that the estimation of insolation can be made only from the routine data.

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A study on the application Heat Pump to Rolling Stock Air conditioner (히트펌프식 냉난방장치의 철도차량 적용에 관한 연구)

  • Kweon, Tae-Kyun;Song, Young-Jeong;Jeong, Gwang-Moo
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1689-1696
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    • 2008
  • Heat pumps transfer heat by circulating a substance called a refrigerant through a cycle of evaporation and condensation. But Heat pumps system by only using heat-source is not efficient. Because the mean temperature of North Korean winter season is low, economy of air heat-source heat pump descend. This paper is practiced the simulation on evaluation criteria for Heat pump heating and cooling systems to Rolling Stock. Efficiency of the heat pump in order improving from certainly the development of the technique will be able to prevent a freezing actual condition must proceed. As a result, Below $-10^{\circ}C$ used heating and cooling systems of heat pump format even in cold winter season and is serviceable confirmed with heat source supply circle of the Rolling Stock.

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The temperature distributions of the curing space according to blocking the opening of gang-form at the apartment in the cold weather (동절기 공동주택 갱폼 개구부 천막보양에 따른 보양 온도 분포 분석)

  • Cho, Hong-Bum;Song, Jin-Hee;Kim, Young-Sun;Choi, Ji-Su;Lee, Kyu-Nam
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.04a
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    • pp.140-141
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    • 2022
  • CFD analysis was performed to analyze the temperature distribution of the inner space of the curing house according to blocking the opening of the gang-form with a tent in case of concrete pouring and heat curing of the apartment house during the winter season. If the gang-form opening is closed with a tent during internal heating using a hot air blower in the winter, the internal temperature rises compared to the non-reserved due to air-tightness of the curing spaces, and uniform temperature distribution can be ensured. In addition, it is possible to increase curing efficiency by reducing the amount of heat supplied and shortening the heating time.

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Analytical Model of Salt Budget in the Upper Indian River Lagoon, Florida USA

  • Kim, Young-Taeg
    • Ocean and Polar Research
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    • v.26 no.1
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    • pp.33-42
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    • 2004
  • Effect of freshwater discharge on the long-term salt balance in the Northern and Central Indian River Lagoon (IRL) is successfully simulated by a new analytical solution to a water balance-based one-dimensional salt conservation equation. Sensitivity tests show that the salinity levels drop abruptly even during the dry season (November to May) due to the high surface runoff discharge caused by tropical storms, depressions, and passage of cold fronts. Increasing surface runoff and direct precipitation has risen by ten times, lowering the salinity level down to 12psu in the Northern Central zone, and to 17 psu in the Northern zone. However, the salinity level in the Southern Central zone has decreased to 25 psu. High sensitivity of the Northern Central zone to freshwater discharge can be partially explained by a rapid urbanization in this zone. During the dry season, less sensitivity of the Southern Central zone to the increased surface runoff is attributed to the proximity of the zone to the Sebastian Inlet and a strong diffusion condition possibly resulting from the seawater intrusion to the surficial aquifer at the Vero Beach. During the wet season, however, the whole study area is highly sensitive to freshwater discharge due to the weak diffusion conditions. High sensitivity of the IRL to the given diffusion conditions guarantees that the fresh-water release occurs during strong wind conditions, achieving both flood control in the drainage basin and a proper salinity regime in the IRL.

Sea Cucumber Apostichopus japonicas Growth in Pond-bottom and Lantern-net Cultures (노지양식장에서 채롱양식과 바닥양식에 따른 해삼(Apostichopus japonicus)의 성장특성)

  • Jeong, U-Cheol;Han, Jong-Cheol;Kang, Seok-Joong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.49 no.3
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    • pp.337-342
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    • 2016
  • Sea cucumbers have been an important part of human diets throughout history; demand is increasing every year, making the species a target for coastal resource development. New harvesting technologies have been developed in response to demand, including nursery production and insemination aquaculture, but such methods produce relatively few individuals and productivity per unit area is very small. For example, captures are prohibited during July and August due to the breeding season, and sea cucumbers aestivate during the hot season and hibernate during the cold season, all factors that limit natural-environment production in Korea. Problems with slow growth of sea cucumbers have been encountered in previous rearing experiments. To assess the importance of feeding ecology on sea cucumber growth, we conducted pond-bottom and lantern-net culture experiments. Results showed that sea cucumbers in bottom cultures grew from 3.06 to 102.59 g, but those in lantern cultures only grew from 25.60 to 28.03 g.

Mechanism for Bank Erosion and Local Scouring in Estuary of the Hangang River

  • Lee, Samhee;Han, Hyeongjun;Choo, Jeongho
    • Journal of Wetlands Research
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    • v.16 no.4
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    • pp.453-462
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    • 2014
  • The levee and bridge pier in estuary of the Hangang River are exposed in a dangerous condition due to bank erosion and local scouring occurred since the summer season in 2011. At first, it is presumed that the high sandbar formed in river channel of the study area was an important element in the occurrence of bank erosion and local scouring. It can be presumed that the record-breaking depth of freezing due to cold wave for the long term during the winter season between 2010 and 2011 as well as the heavy intensive rainfall of 2011 had a decisive effect on the first damage of A section. The second damage of B section mainly occurred around the bridge pier constructed on the high water channel before it was washed away during the winter season between 2011 and 2012. It is considered that the second damage was caused by ice formation and ice floes.

A Study on Exterior Features and Characteristics of Gloves in the Modern Fashion (현대패션에 나타난 장갑의 외적 형태와 특성에 관한 연구)

  • Kim, Sun-Young
    • The Research Journal of the Costume Culture
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    • v.16 no.2
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    • pp.235-248
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    • 2008
  • This study is on the characteristics of gloves in the modern fashion and has the purpose to review the style and the feature of gloves coordinated with clothes variously. The study started firstly with reviewing the related literature for the information of the origin, the process of development and the sort of gloves and then verified the results with photographs in the fashion magazines and collections at home and abroad since 1990s. The first characteristic is utility. Lining and covered materials use the materials excellent for keeping warm as the original purpose of wearing gloves is to protect hands against cold weather. It is demonstrated in the fashion collections that coordinating sieves appeals more often in fall-winter season than in spring-summer season. The second is sense of fashion. Gloves are normally coordinated with same materials and colors of clothes. But, gloves could create infinite varieties, make sufficient images through stressing splendid colors on achromatic colored clothes, shaping unique styles, transforming with various materials and ornaments. The last is sense of deconstruction. Gloves are transformed as a sort of clothes beyond the original use. Gloves are coordinated transcending the conventional thoughts, which makes it possible that Stoves appear in summer season, not in winter. Coordinating gloves appears free and unique through atypical formation.

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Influence of Rainfall on Germination of Malting Barley at Harvesting Season (수확기의 강우가 맥주보리 발아에 미치는 영향)

  • 김석현;최창휴
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.6
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    • pp.705-710
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    • 1995
  • In order to find out the effect of rainfall at harvesting season on germination of malting barley, the seeds sampled from Cheju island and southern part of Korea were examined. The germination rate of seeds from Cheju island where rainfall was frequent at harvesting season, ranged from 46 to 71%, even though disease infection of the seeds was not that serious as would be expected. High sugar content of seed was resulted from the degradation of carbohydrates during the harvest season. From TZ test the rainfall - affected seeds were found to be highly viable but in the state of secondary dormancy. Results of cold germination test showed that the seeds were recovered from the secondary dormancy. Therefore, it was recommended that the seeds affected by the rainfall at harvesting season should be utilized after 12 months when the dormancy period terminated. The germination percent of the seeds was significantly enhanced by prechilling and / or 1 ppm gibberellic acid treatment. Different seed lots showed different rate of germination and the degree of dormancy.

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