• Title/Summary/Keyword: December cold

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The Effect of Clothing Habits on Cold Acclimatization (의복착용 습관이 추위적응 능력에 미치는 영향)

  • 이종민;이순원
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.3
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    • pp.536-543
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    • 1997
  • The subjects wearing cool clothing (C group) or warm clothing (W stoup) in daily life from September to February of the following year were tested to examine whether cold acclimatization takes place by clothing habits. Subjects rested at 25$\pm$1$^{\circ}C$, then were exposed to 15$\pm$1$^{\circ}C$, 50$\pm$5% R.H. for 90 min in September, November, December, and February. Rectal temperature (Tre) of C group after 90 min cold exposure did not drop below the Tre in $25^{\circ}C$ throughout the study. W group's Tre, however, dropped below the temperature in 25t from December. Shivering stopped after December in C group while W group continued to show it for the whole study. In resting, C group showed higher heat production than W group in February, and the rate of increase in heat production during cold exposure was smaller in C group than W group in February. C group showed less cold sensation than W group in the same coldness. These results suggest that the level of cold acclimatization may be improved by the habits wearing less clothes in daily life.

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Seasonal Change in the Reproductive Pattern of the Marine Cladoceran Podon polyphemoides in Korean Waters

  • YOO Kwang-Il;KIM Se-Wha
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.23 no.2
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    • pp.141-144
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    • 1990
  • Seasonal change in the reproductive pattern of the marine Cladoceran Podon polyphemoides, was studied using materials collected monthly during the period from January to December 1986 in Yongil Bay, Korea. The relative abundance of P. polyphemoides exceeded $10\%$ of total zooplankton in July. While the species remained as a minor components of the zooplankton community during the other periods of occurrence from June to December. Occurrence of sexual individuals of P. polyphemoides (males and gamogenetic females) in higher proportion in cold months ($30\%$ in November and $40\%$ in December) suggests that resting egg production of this species is largely confined to cold monthis in Korean waters as an overwintering strategy.

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Ultrastructural Changes in the Cortical Cell Mulberry Trees(Morus)during Wintering Period (越冬期 뽕나무 가지 皮層部 細胞內 微細構造의 變化)

  • 최영철;유근섭;안영희
    • Journal of Sericultural and Entomological Science
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    • v.40 no.2
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    • pp.91-96
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    • 1998
  • In relation to cold acclimation, this experiment was carried out to understand the changes of the cortical cells in the living barks of the mulberry during wintering period. The living barks of three mulberry varieties(Kaeryangppong, Shinilppong and Yongcheonppong) were sampled from December, 1995 to March, 1996. The result of this experiment was summarized as follows. The cortical cells in the living barks of the mulberry in December were filled with small vacuoles. Plastids and mitochondrias were located near the nucleus. At this time, almost all starch granules disappeared from the plastids. In January and February, mitochondria, palstids and microbodys of the cortical cell were observed. As increasing temperature from March, dictysomes and polysomes were sparse. Again, starch granules disappeared were observed in the plastids. From the above result. starch granules in plastide of the cortical cell of the mulberry disappeared during cold acclimation stage. After late January, Proplastid was observed in the cortical cell and the ultrastructures of cortical cell were actively changed.

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Assessment of Climate Variability over East Asia-Korea for 2015/16 Winter (2015/16 겨울 동아시아-한반도 기후 특성 분석)

  • Jeong, Jee-Hoon;Park, Tae-Won;Choi, Ja-Hyun;Son, Seok-Woo;Song, Kanghyun;Kug, Jong-Seong;Kim, Baek-Min;Kim, Hyun-kyung;Yim, So-Young
    • Atmosphere
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    • v.26 no.2
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    • pp.337-345
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    • 2016
  • This paper is to assess the state of climate over East Asia and Korea during 2015/16 winter. There was a distinct intraseasonal climate variation during the period: the record-breaking warmth in December 2015 vs. strong cold surge outbreaks in January 2016. It is suggested that the anomalous warming in December 2015 was contributed by an intensification of Kuroshio anticyclone associated with 2015/16 El $Ni{\tilde{n}}o$ and polar vortex intensification. In January 2016, a strong cold surge outbroke over East Asia bringing severe cold more than two weeks. The cold surge was a blocking-type one which followed extremely negative AO developed from early January. It was suggested that the intensification of cold surge might be contributed indirectly by a strong Arctic warming and MJO activity during the period.

Local Enhancement Mechanism of Cold Surges over the Korean Peninsula (한반도 한파의 지역적 강화 메커니즘)

  • Lee, Hye-Young;Kim, Joowan;Park, In-Gyu;Kang, Hyungyu;Ryu, Hosun
    • Atmosphere
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    • v.28 no.4
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    • pp.383-392
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    • 2018
  • This study investigates synoptic characteristics of cold surges over South Korea during winter season (December-February). A total of 63 cold events are selected by quantile regression analysis using daily mean temperature observations from 11 KMA stations for 38 years (1979/80-2016/17). Large-scale pressure pattern during the cold surges is well characterized by high over Siberia and low over Aleutian regions, which elucidates cold advection over the Korean peninsula. However, the large-scale pattern cannot successfully explain the observed sudden decrease of temperature during the cold surges. Composite analyses reveal that a synoptic-scale cyclone developing over the northern Japan is a key feature that significantly contribute to the enhancement of cold advection by increasing pressure gradient over the Korean peninsula. Enhanced sensible and latent heat fluxes are observed over the southern ocean of Korea and Japan during the cold surges due to temperature and humidity differences between the near surface and the lower atmosphere over the ocean. The evaporated water vapor transported toward the center of the surface cyclone and condenses in the lower-to-middle troposphere. The released energy likely promotes the development of the surface cyclone by inducing positive PV near the surface of the heating region.

Improvement of roll force precalculation accuracy in cold mill using a corrective neural network (보정신경망을 이용한 냉연 압하력 적중율 향상)

  • 이종영;조형석;조성준;조용중;윤성철
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1083-1086
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    • 1996
  • Cold rolling mill process in steel works uses stands of rolls to flatten a strip to a desired thickness. At cold rolling mill process, precalculation determines the mill settings before a strip actually enters the mill and is done by an outdated mathematical model. A corrective neural network model is proposed to improve the accuracy of the roll force prediction. Additional variables to be fed to the network include the chemical composition of the coil, its coiling temperature and the aggregated amount of processed strips of each roll. The network was trained using a standard backpropagation with 4,944 process data collected from no.1 cold rolling mill process from March 1995 through December 1995, then was tested on the unseen 1,586 data from Jan 1996 through April 1996. The combined model reduced the prediction error by 32.8% on average.

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Effect of Cooling Hands in the Cold Water for the Physiological Responses and Clothing Comfort -Focused on Vascular Hunting Reaction, Thermal Sensation and Pain Sensation- (손의 한랭자극이 인체생리반응과 의복의 쾌적성에 미치는 영향 -한랭혈관반응, 온랭감각, 한랭통증을 중심으로-)

  • 이원자
    • The Research Journal of the Costume Culture
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    • v.12 no.2
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    • pp.279-289
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    • 2004
  • This study was conducted to compare the hunting reaction of finger in the cold water. Finger skin temperature is measured the left middle finger tip immersion in cold water of 5℃ for 30 minutes and measurements were made on finger skin temperature(Ts), thermal comfort, and cold pain sensations during the experiment at the spring (March) and Winter(December). Results were follows. Is before immersion was at the highest in spring and at the lowest in winter and was closely related to the indoor temperature Ts during immersion and recovery. Mean of finger skin temperature(MST), the skin temperature at the first rise(TTR) and amplitude of finger skin temperature reaction during immersion(AT) were significant higher in spring than that in winter(P<.01). The lowest skin temperature(LST) during the cold water immersion were significantly higher in spring than that in winter (P<.05). The frequency of the appearance of cold-Induced vase dilation(CIVD) was higher in spring than that in winter. However, time for the first temperature(TTR) and recovery time(RT) had no seasonal variation. In addition, cold pains during immersion were felt more strongly in spring than in winter. Local thermal sensation, finger thermal sensation in dynamic state during hand immersion was different from that in the Winter. Spring was slowly cold in cold water immersion.

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Studies on the Mulberry Graftages IV. Cold Hardiness in December (뽕나무 접목묘에 관한 연구 IV. 12월 중의 내동성)

  • Lee, Won-Ju;Lee, Ju-Won;Park, Gwang-Jun
    • Journal of Sericultural and Entomological Science
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    • v.31 no.2
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    • pp.65-68
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    • 1989
  • Cold hardiness of mulberry graftages was examined with two varieties, Kaeryangppong and Keomseolppong in early December. Exposure temperatures were three levels (-5, -10 and -15$^{\circ}C$) at the 4 exposure times (6, 12, 24 and 48 hrs). No damage showed at -5$^{\circ}C$ for 48 hrs. Survival rate decreased sharply from -10$^{\circ}C$, regardless exposure times. There was no survivals from -10$^{\circ}C$ for 12 hrs in Kaeryangppmong and from -15$^{\circ}C$ for 6 hrs in Keomseolppong. This suggested Keomseolppong was stronger in cold than kaeryangppong. Regrowth decreased drastically from -10$^{\circ}C$.

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Characteristic Features Observed in the East-Asian Cold Anomalies in January 2011 (2011년 1월의 동아시아 한랭 아노말리 특성)

  • Choi, Wookap;Jung, Jiyeon;Jhun, Jong-Ghap
    • Atmosphere
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    • v.23 no.4
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    • pp.401-412
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    • 2013
  • East Asia experienced extremely cold weather in January 2011, while the previous December and the following February had normal winter temperature. In this study National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data are used to investigate the characteristic features observed in the meteorological fields such as temperature, sea-level pressure, geopotential height, and wind during this winter period. In January the planetary-wave pattern is dominated by stationary-wave form in the mid-to-high latitude region, while transient waves are significant in the previous month. To understand the planetary-wave features quantitatively, harmonic analyses have been done for the 500-hPa geopotential height field. In the climatological-mean geopotential heights the wave numbers 1, 2, and 3 are dominant during the whole winter. In January 2011 the waves of number 1, 2, and 3 are dominant and stationary as in the climatological-mean field. In December 2010 and February 2011, however, the waves of number 4, 5, and 6 play a major role and show a transient pattern. In addition to the distinctive features in each month the planetary-wave patterns dependent on the latitude are also discussed.

Nursing Protocols of Cold Application in Different Medical Institutions in Korea (전국 의료기관의 냉 요법 실무지침 및 임상간호사의 냉 요법 실무 현황)

  • Shin, Yong Soon
    • Journal of Korean Clinical Nursing Research
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    • v.21 no.3
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    • pp.355-365
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    • 2015
  • Purpose: The purpose of this study was to evaluate nursing protocols for superficial cryotherapy in different medical institutions. Methods: The study was conducted with a cross-sectional descriptive design. The medical institutions including general hospitals, hospitals, and geriatric hospitals were randomly selected. A total of 435 nurses from 126 institutions completed a questionnaire. Data were collected from December 2014 to June 2015. Results: Forty-two institutions (39.5%) had nursing protocol for cryotherapy. The nurses reported that durations of cold application were 2 minutes to 5 hours. Frequently used cold therapy devices in order of frequency were frozen gel packs, ice packs, and frozen IV fluid bags. There were variances in the duration of cold application according to the types of institution ($x^2=7.78$, p=.020) and nursing units ($x^2=26.42$, p<.001). In addition, intervals of cold application were different according to the nursing units (x=12.23, p=.032). There were differences in cold application instruments by regional groups (x=70.38, p<.001). Most of the nurses (95.6%) responded that national nursing protocol for superficial cryotherapy were needed. Conclusion: There were difficulties in providing consistent nursing interventions because of the practical differences and absence of evidence-based guidelines for cryotherapy. The researchers recommend that basic studies with various instruments be conducted and proper nursing protocols be developed for cryotherapy.