• Title/Summary/Keyword: Over winter

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Why Are Peak Loads Observed during Winter Months in Korea?

  • KIM, JEE YOUNG;OH, HYUNGNA;CHOI, KYUNG-MEE
    • KDI Journal of Economic Policy
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    • v.41 no.1
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    • pp.43-58
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    • 2019
  • Since 2009, electricity consumption has developed a unique seasonal pattern in South Korea. Winter loads have sharply increased, and they eventually exceeded summer peaks. This trend reversal distinguishes these load patterns from those in the USA and the EU, where annual peaks are observed during the summer months. Using Levene's test, we show statistical evidence of a rise in temperature but a decrease in variance over time regardless of the season. Despite the overall increase in the temperature, regardless of the season there should be another cause of the increased demand for electricity in winter. With the present study using data from 1991 to 2012, we provide empirical evidence that relatively low electricity prices regulated by the government have contributed significantly to the rapid upward change in electricity consumption, specifically during the winter months in the commercial sector in Korea.

A Comparative Analysis on Concentration of Pollutants in Housing Indoor-Air between Winter and Summer (주택 실내 공기중 오염물질 농도의 동절기와 하절기 비교 분석)

  • Nam, Ki-Cheul;Lee, Young-Han;Choi, Bong-Seok
    • KIEAE Journal
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    • v.17 no.3
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    • pp.125-131
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    • 2017
  • Purpose: The study is to measure concentrations of indoor air pollutants in housing and to analyze the characteristics of pollutants in housing indoor-air between summer and winter comparatively. The research result could be used as data for public health through indoor air quality management of existing housing and more as a reference for new housing. Method: It was investigated 24 middle class housings of metropolitan area in winter which have been built for the past 30 years. Concentration of HCHO, TVOC was investigated in living room at morning and night and concentration of $CO_2$ was investigated in living room and master bedroom at morning and night. SKT100-X5 was used for concentration of HCHO, TVOC and ZGm053UK for concentration of $CO_2$. The characteristics of HCHO, TVOC, $CO_2$ concentration in winter were analyzed and then the concentrations in winter were analyzed the concentrations in summer being preceding research comparatively. Result: Average concentration of TVOC in winter was 2.7 times more than that of TVOC in summer, average concentration of HCHO in winter was about 2.0 times more than that of HCHO in summer. Average concentration of $CO_2$ in the morning at living room in winter was 1.3 times more than that of $CO_2$ in summer. Average concentration of $CO_2$ in the morning at master bedroom in winter was 1.1 times more than that of $CO_2$ in summer. Average concentration of TVOC was 1.31 times more than that of HCHO and standard deviation of that was 1.73 times higher. Average concentration of $CO_2$ was almost nearly close or over to 1,000ppm being criteria of the Ministry of Environment.

Near Future Projection of Extreme Temperature over CORDEX-East Asia Phase 2 Region Using the WRF Model Based on RCP Scenarios (RCP 시나리오 기반 WRF를 이용한 CORDEX-동아시아 2단계 지역의 가까운 미래 극한기온 변화 전망)

  • Seo, Ga-Yeong;Choi, Yeon-Woo;Ahn, Joong-Bae
    • Atmosphere
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    • v.29 no.5
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    • pp.585-597
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    • 2019
  • This study evaluates the performance of Weather Research and Forecasting (WRF) model in simulating temperature over the COordinated Regional climate Downscaling EXperiment-East Asia (CORDEX-EA) Phase 2 domain for the reference period (1981~2005), and assesses the changes in temperature and its extremes in the mid-21st century (2026~2050) under global warming based on Representative Concentration Pathway (RCP) scenarios. MPI-ESM-LR forced by two RCP scenarios (RCP2.6 and RCP8.5) is used as initial and lateral boundary conditions. Overall, WRF can capture the observed features of temperature distribution reflecting local topographic characteristic, despite some disagreement between the observed and simulated patterns. Basically, WRF shows a systematic cold bias in daily mean, minimum and maximum temperature over the entire domain. According to the future projections, summer and winter mean temperatures over East Asia will significantly increase in the mid-21st century. The mean temperature rise is expected to be greater in winter than in summer. In accordance with these results, summer (winter) is projected to begin earlier (later) in the future compared to the historical period. Furthermore, a rise in extreme temperatures shows a tendency to be greater in the future. The averages of daily minimum and maximum temperatures above 90 percentiles are likely to be intensified in the high-latitude, while hot days and hot nights tend to be more frequent in the low-latitude in the mid-21st century. Especially, East Asia would be suffered from strong increases in nocturnal temperature under future global warming.

A Study on the Current State of Korean Military Winter Uniform Tops (한국 군용 방한복 상의에 대한 실태조사)

  • Jeong, Mi-Ae;Nam, Yun-Ja
    • Journal of the Korean Society of Costume
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    • v.66 no.5
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    • pp.66-81
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    • 2016
  • This study is designed to understand the problems of existing Korean male soldiers' winter uniform tops by researching its current state, and contribute to developing uniforms with improved size and motion appropriateness. Military bases were visited to research satisfaction of size and motion appropriateness of the current winter uniform tops. 193 soldiers were surveyed and interviewed, and the shape and fit of the standard sizes of the inner and outer layers of the current winter uniform were analyzed. Findings of this study are as follows. 1) Compared to the new combat uniforms that soldiers were wearing in their appropriate size (of the 44 sizes), there were many cases where the soldiers were not wearing winter uniform inner (of the 8 sizes) or outer (of the 18 sizes) layers in the correct size for their body. 2) A total of 37 combat uniform sizes appropriate for the body shapes were expected to be newly applied, and inside and outside layers of winter tops would be presented as sets of 14 different sizes in step with the new combat uniform sizes, instead of the existing 8 inside layer sizes and 18 outside layer sizes. 3) The inner and outer layer of the existing winter uniform tops had several problems with the shape and fit. First, the inner layer was shorter than the combat uniform. Its shoulder width was wide, but the sleeve length was short creating lack of coverage, and the angle connecting the sleeve and bodice was very small creating a high sleeve cap curve and narrow sleeve width that make motions difficult and cause discomfort. As for the outer layer, the hem moved up when soldiers bent over or adjusted the waist string so the top could not sufficiently cover, the shoulder width was wide and the sleeve length was short, requiring improvements.

Long-term Variation in the Catch of Major Small Pelagic Fishes Related to Winter Warming in the South Sea, Korea

  • Lee, Seung-Jong;Go, You-Bong
    • Fisheries and Aquatic Sciences
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    • v.10 no.1
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    • pp.43-52
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    • 2007
  • The relationships among long-term climatic change in the southern part of the Korean peninsula, oceanic conditions of the South Sea, Korea, and winter catches of major small pelagic fishes were analyzed using 33 years of time-series data from 1971-2003. In the early 1990s, winter climatic conditions in the southern part of the Korean peninsula shifted to a warmer regime with higher air temperature, weaker wind speed, and lower relative humidity. Also, winter sea surface temperature (SST) became consistently higher in the South Sea. The annual catch of major small pelagic fishes in the South Sea increased dramatically in the mid 1990s, whereas the catch of total fishes decreased in the late 1980s. In particular, the winter catch started to increase markedly in the late 1980s, and has remained over 120,000 M/T since the late 1990s. Correlation analysis of the winter catch of major small pelagic fishes and environmental factors showed that catch was correlated with air temperature (r=0.468, P< 0.01), wind speed (r=-0.732, P< 0.01), relative humidity (r=-0.73l, P< 0.01), and SST (r=0.672, P< 0.01). Multiple regression analysis between the winter catch of major small pelagic fishes (Y) and environmental factors (X) resulted in the equation: $Y=-0.017-0.217\;X_3-0.486\;X_4+0.325\;X_5(R^2=0.754,\;P<0.000)$.

Intraspecific Variation in Leaf Life Span for the Semi-evergreen Liana Akebia trifoliata is Caused by Both Seasonal and Aseasonal Factors in a Temperate Forest

  • Kohei, Koyama;Kikuzawa, Kihachiro
    • Journal of Ecology and Environment
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    • v.31 no.3
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    • pp.207-211
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    • 2008
  • We investigated the leaf demography of a temperate woody liana, Akebia trifoliata, in a temperate forest in Japan, Akebia is semi-evergreen: some leaves are shed before winter, while others remain through the winter. Previous studies of semi-evergreen species found that variation in leaf life span was caused by variation in the timing of leaf emergence, Leaves that appeared just before winter over-wintered, while leaves appearing earlier were shed, However, it is unclear whether leaves of the same cohort (i.e., leaves that appear at the same time within a single site) show variation in life span under the effect of strong seasonality. To separate variation in life span among the leaves in each cohort from variation among cohorts, we propose a new method - the single leaf diagram, which shows the emergence and death of each leaf. Using single leaf diagrams, our study revealed that Akebia leaves within a cohort showed substantial variation in life span, with some over-wintering and some not. In addition, leaves on small ramets in the understory showed great variation in life span, while leaves on large ramets, which typically reach higher positions in the forest canopy, have shorter lives, As a result, small ramets were semi-evergreen, whereas large ramets were deciduous, The longer lives of leaves on small ramets can be interpreted as a shade-adaptive strategy in understory plants.

A Fingerprint of Global Warming Appeared in Winter Precipitation across South Korea (우리나라 겨울철 강수에 나타난 지구온난화의 징후)

  • Choi, Gwang-Yong;Kwon, Won-Tae
    • Proceedings of the Korea Water Resources Association Conference
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    • 2008.05a
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    • pp.992-996
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    • 2008
  • In this study, changes in precipitation across South Korea during snow seasons (November-April) and their potential are examined. Current (1973/74-2006/07) and future (2081-2100) time series of snow indices including snow season, snow-to-precipitation ratio, and snow impossible day are extracted from observed snow and precipitation data for 61 weather stations as well as observed and modeled daily temperature data. Analyses of linear trends reveal that snow seasons have shortened by 3-13 days/decade; that the snow-to-precipitation ratio (the percentage of snow days relative to precipitation days) has decreased by 4-8 %/decade. These changes are associated with pronounced formations of a positive pressure anomaly core over East Asia during the positive Arctic Oscillation winter years since the late 1980s. A snow-temperature statistical model demonstrates that the warming due to the positive core winter intensifies changes from snow to rain at the rate of $4.7cm/^{\circ}C$. The high pressure anomaly pattern has also contributed to decreases of air-sea thermal gradient which are associated with the reduction of snow could formation. Modeled data predict that a fingerprint of wintertime global warming causing changes from snow to rain will continue to be observed over the 21st century.

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Analysis of Regional Occurrence of Hail over Korean Peninsular (국내의 지역별 우박 발생 빈도 분석)

  • Lee, Young-Kyu;Lee, Jae-Soo;Lee, Sung-Su;Kim, Hak-Sun
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.81-84
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    • 2007
  • Data for occurrence of hail over Korean Peninsula for the period 1961-2005 are obtained from the Korea Meteorological Administration (KMA). According to the average occurrences during each season in Korea Peninsular, hail days are almost distributed uniformly in the spring, fall and winter, except the summer and have averages of 5 days for each season. Analysis of regional occurrence of hail shows that inland of Korea Peninsular is vulnerable to hail in the spring and summer and the islands of Ullung, Baegryeong and Cheju and the coastal regions vulnerable in the fall and winter. It can be postulated that these seasonal patterns of hail is affected by the Monsoon effect.

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Characteristics of Micromiling, Farina Milling, and Cooling Quality of Farina Spaghetti from Kansas Hard Red Winter Wheat (켄사스 경질 붉은밀의 소규모 시험 제분 및 페리나 제분 특성과 이들로부터 제조된 스파게티의 조리특성)

  • 김혁일;김창순
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.23 no.4
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    • pp.686-697
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    • 1994
  • The hardness of hard red winter (HRW) wheat had an effect on the yield of farina , as it positively correlated with the coarse fraction (over 34W) and negatively correlated with the flour fraction from farina milling. But it did not show any significances on flour milling from the micromilling process. The flour yields was better correlated with the break flour fraction (r=0.730 than with reduction flour (r=0.27). The farina yield was controlled by a fraction over 34W (coarse granule0. Protein was the most important single factor for the quality of cooked farina spaghetti, but not for flour milling or farina milling. On the other hand, hardness was important in the production of farina milling , whereas it did not govern spaghetti cooking quality, Environmental factors affected the quality of cooked spaghetti as much as varieties of HRW wheats. The quality of cooked farina spaghetti generally correlated with the protein in the location composites of wheats. Higher protein content wheats showed better spaghetti cooking quality.

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Gruwth Charateristics and Chemical Components of Forage Rye in Southern-Region of Korea (남부지방에서 청예호밀의 생육특성 및 성분함량)

  • 안계수;정동희;황종진;임준택;권병선
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.14 no.1
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    • pp.42-49
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    • 1994
  • To examine the productivity, growth characteristics, and nutritive value of forage rye at the southern region of Korea, fourteen varieties of rye were sown at Nov. 13, 1992 at the plot of experiment farm of Crop Experiment Station, Mokpo Branch, and over winter survival rate, heading date, yield, yield components and nutritional values were measured. All the varieties used in this experiment showed 100% over winter survival rate at the sowing date of Nov. 13. Heading dates of all the varieties ranges from Apr. 25 to May 10, which seems to be early enough to get high yield. The varieties, Paldal-hod, and Danko introduced from Japan appear to be the most recommended ones in the southem region of Korea. They showed early heading date of Apr. 25, large plant height, greater number of leaves, high yield, low content of crude fiber and crude fat, high crude protein, NFE, and crude a5h.

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