• Title/Summary/Keyword: Low-level event

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Atmospheric Vertical Structure of Heavy Rainfall System during the 2010 Summer Intensive Observation Period over Seoul Metropolitan Area (2010년 여름철 수도권 집중관측기간에 나타난 호우 시스템의 대기연직구조)

  • Kim, Do-Woo;Kim, Yeon-Hee;Kim, Ki-Hoon;Shin, Seung-Sook;Kim, Dong-Kyun;Hwang, Yoon-Jeong;Park, Jong-Im;Choi, Da-Young;Lee, Yong-Hee
    • Journal of the Korean earth science society
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    • v.33 no.2
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    • pp.148-161
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    • 2012
  • The intensive observation (ProbeX-2010) with 6-hour launches of radiosonde was performed over Seoul metropolitan area (Dongducheon, Incheon Airport, and Yangpyeong) from 13 Aug. to 3 Sep. 2010. Five typical heavy rainfall patterns occurred consecutively which are squall line, stationary front, remote tropical cyclone (TC), tropical depression, and typhoon patterns. On 15 Aug. 03 KST, when squall line developed over Seoul metropolitan area, dry mid-level air was drawn over warm and moist low-level air, inducing strong convective instability. From 23 to 26 Aug and from 27 to 29 Aug. Rainfall event occurred influenced by stationary front and remote TC, respectively. During the stationary frontal rainy period, thermal instability was dominant in the beginning stage, but dynamic instability became strong in the latter stage. Especially, heavy rainfall occurred on 25 Aug. when southerly low level jet formed over the Yellow Sea. During the rainy period by the remote TC, thermal and dynamic instability sustained together. Especially, heavy rainfall event occurred on 29 Aug. when the tropical air with high equivalent potential temperature (>345 K) occupied the deep low-middle level. On 27 Aug. and 2 Sep. tropical depression and typhoon Kompasu affected Seoul metropolitan area, respectively. During these events, dynamic instability was very strong.

Analytic comparison of Clothing Purchase Behavior between Rural and Urban Housewives (농촌.도시 주부의 의복 구매 행동 비교 분석)

  • 이지연;박재옥
    • Journal of the Korean Home Economics Association
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    • v.40 no.1
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    • pp.209-224
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    • 2002
  • In this study, Rural and urban housewives were compared in terms of their clothing practical use and clothing buying behavior. For the analysis, a nation-wide stratified sampling was made across the rural and urban areas. As a result, 400 subjects of housewives were selected and were asked to answer the questionnaire. Results of the analysis were as follows: 1. Both rural and urban housewives were found to have reliable knowledge about the kinds of clothes they are possessing. However, there were significant differences in the knowledge level of clothing practice methods, in clothing patterns of one′s favor, and in clothing buying behavior by the type of clothing. 2. With regard to the clothing buying behavior by the type of clothing, several differences were found between rural and urban housewives. Purchase motivation for formal wear, was found to be "I don′t have one" in overall, yet having a significant frequency difference between rural and urban housewives. Major evaluation criteria were "color and design" and "fits to me" for formal wear and "comfort and fitness" and "price" for casual wear, also having a significant frequency difference between rural and urban housewives. 3. Rural area housewives bought their formal wear in stores offering "low price or sale" while urban housewives looked at "quality and variety". The major source of information was "display and direct observation" and "previous experience" in both cases. The rural housewives bought clothes when they had any "event" and urban housewives bought them when they had "extra money or sale".

Lysosomal acid phosphatase mediates dedifferentiation in the regenerating salamander limb

  • Ju, Bong-Gun;Kim, Won-Sun
    • Animal cells and systems
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    • v.14 no.2
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    • pp.73-81
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    • 2010
  • In this study, monoclonal antibodies against lysosomal acid phosphatase (LAP) of a salamander, Hynobius leechii, were used to determine the spatial and temporal expression of the LAP in the regenerating limbs. The Western blot and immunohistochemical analysis in the limb regeneration revealed that LAP was highly expressed at the dedifferentiation stage, especially in the wound epidermis and dedifferentiating limb tissues such as muscle and cartilage. With RA treatment, the LAP expression became upregulated in terms of both level and duration in the wound epidermis, blastemal cell and dedifferentiating limb tissues. In addition, in situ activity staining of LAP showed a similar result to that of immunohistochemistry. Thus, the activity profile of LAP activity coincides well with the expression profile of LAP during the dedifferentiation period. Furthermore, to examine the effects of lysosomal enzymes including LAP on salamander limb regeneration, lysosome extract was microinjected into limb regenerates. Interestingly, when the lysosome extract was microinjected into limb regenerates with a low dose of RA($50\;{\mu}g/g$ body wt.), skeletal pattern duplication occurred frequently in the proximodistal and transverse axes. Therefore, lysosomal enzymes might cause the regenerative environment and RA plays dual roles in the modification of positional value as well as evocation of extensive dedifferentiation for pattern duplication. In conclusion, these results support the hypothesis that dedifferentiation is a crucial event in the process of limb regeneration and RA-evoked pattern duplication, and lysosomal enzymes may play important role(s) in this process.

Feasibility Study for College of Medicine Establishment in Western Region of Chungcheongnam-do (충청남도 서부권 의과대학 설립에 대한 타당성 연구)

  • Kim, Jeong-Koo;Lee, Young-Shin;Kim, Woong-Yi;Yi, Jin-Bok
    • Journal of radiological science and technology
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    • v.43 no.4
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    • pp.289-295
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    • 2020
  • This study investigated the feasibility of establishing a college of medicine in the western region of Chungnam to fill the gap in the medical doctor in charge of essential medical care in the region. Currently, the level of medical services in Chungnam is low compared to provinces across the country and in particular, 7 cities and towns, which account for 760,000 people, one-third of Chungnam's population, are located in the western regions of Chungnam. Because of this, in the event of an emergency patients, it is necessary to travel to Cheonan, Daejeon, Seoul, etc. where the regional emergency medical center is located for more than 1 hour and 30 minutes. In the case of critically ill and emergency patients transfer, it is a situation that misses the golden time and causes valuable loss of life. In order to improve the medical environment in the western region of Chungnam and improve the lives of residents in vulnerable areas of medical services, it is believed that establishing a college of medicine in the western region of Chungnam is essential.

Implementation of Under Voltage Load Shedding for Fault Induced Delayed Voltage Recovery Phenomenon Alleviation

  • Lee, Yun-Hwan;Park, Bo-Hyun;Oh, Seung-Chan;Lee, Byong-Jun;Shin, Jeong-Hoon;Kim, Tae-Kyun
    • Journal of Electrical Engineering and Technology
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    • v.9 no.2
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    • pp.406-414
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    • 2014
  • Significant penetration of induction motor loads into residential neighborhood and commercial regions of local transmission systems at least partially determine a vulnerability to a fault induced delayed voltage recovery (FIDVR) event. Highly concentrated induction motor loads with constant torque could stall in response to low voltages associated with system faults. FIDVR is caused by wide spread stalling of small HVAC units (residential air conditioner) during transmission level faults. An under voltage load shedding scheme (UVLS) can be an effective component in a strategy to manage FIDVR risk and limit the any potential disturbance. Under Voltage Load Shedding take advantage of the plan to recovery the voltage of the system by shedding the load ways to alleviation FIDVR.

Numerical simulations of mountain winds in an alpine valley

  • Cantelli, Antonio;Monti, Paolo;Leuzzi, Giovanni;Valerio, Giulia;Pilotti, Marco
    • Wind and Structures
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    • v.24 no.6
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    • pp.565-578
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    • 2017
  • The meteorological model WRF is used to investigate the wind circulation in Valle Camonica, Italy, an alpine valley that includes a large subalpine lake. The aim was to obtain the information necessary to evaluate the wind potential of this area and, from a methodological point of view, to suggest how numerical modeling can be used to locate the most interesting spots for wind exploitation. Two simulations are carried out in order to analyze typical scenarios occurring in the valley. In the first one, the diurnal cycle of thermally-induced winds generated by the heating-cooling of the mountain range encircling the valley is analyzed. The results show that the mountain slopes strongly affect the low-level winds during both daytime and nighttime, and that the correct setting of the lake temperature improves the quality of the meteorological fields provided by WRF significantly. The second simulation deals with an event of strong downslope winds caused by the passage of a cold front. Comparisons between simulated and measured wind speed, direction and air temperature are also shown.

Analysis of Reflux Cooling in the SG U-Tubes Under Loss of RHRS During Midloop Operation with Primary System Partly Open

  • Son, Young-Seok;Kim, Won-Seok;Kim, Kyung-Doo;Chung, Young-Jong;Chang, Won-Pyo
    • Nuclear Engineering and Technology
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    • v.30 no.2
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    • pp.112-127
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    • 1998
  • The present study is to assess the applicability of the best-estimate thermal-hydraulic codes, RELAP5/MOD3.2 and CATHARE2V1.3U, to the analysis of thermal-hydraulic behavior in PWRs during midloop operation following the loss of RHRS. The codes simulate an integral test, BETHSY 6.94, which was conducted in the large scale test facility of BETHSY in France. The test represents the accident where the loss of RHRS occurs during midloop operation with the pressurizer and upper head vents open and the sight level indicator broken. Besides, the hot legs are half filled with water and the upper parts of the primary cooling system are filled with nitrogen, with a letdown line open and only one SG available. The purposes of this study are to understand the physical phenomena associated with reflux cooling in the 5G U-tubes when noncondensable gas is present under low pressure and to assess the applicability of the codes to simulate the loss of RHRS event by comparing the predictions with the test results. The results of the study may contribute to actual applications for plant safety evaluation and description of the emergency operating procedure.

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A Study on the Synoptic Structural Characteristics of Heavy Snowfall Event in Yeongdong Area that Occurred on 20 January, 2017 (2017년 1월 20일 발생한 강원 영동대설 사례에 대한 대기의 구조적 특성 연구)

  • Ahn, Bo-Young;Lee, Jeong-sun;Kim, Baek-Jo;Kim, Hui-won
    • Journal of Environmental Science International
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    • v.28 no.9
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    • pp.765-784
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    • 2019
  • The synoptic structural characteristics associated with heavy snowfall (Bukgangneung: 31.3 cm) that occurred in the Yeongdong area on 20 January 2017 was investigated using surface and upper-level weather charts, European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data, radiosonde data, and Moderate Resolution Imaging Spectroradiometer (MODIS) cloud product. The cold dome and warm trough of approximately 500 hPa appeared with tropopause folding. As a result, cold and dry air penetrated into the middle and upper levels. At this time, the enhanced cyclonic potential vorticity caused strong baroclinicity, resulting in the sudden development of low pressure at the surface. Under the synoptic structure, localized heavy snowfall occurred in the Yeongdong area within a short time. These results can be confirmed from the vertical analysis of radiosonde data and the characteristics of the MODIS cloud product.

Information Effect of New Office Investments and Determinant of Firm Value (사옥신축의 정보효과와 기업가치 결정요인에 대한 연구)

  • Lee, Jin-Hwon;Lee, Po-Sang
    • Asia-Pacific Journal of Business
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    • v.11 no.3
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    • pp.95-106
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    • 2020
  • Purpose - This study examines the information effect of the disclosure of new office investments on the Korean stock market and investigates determinant of performance of sample firms. Design/methodology/approach - The sample consists of companies listed on the Korean Exchange that announced investments in new office construction for eleven-years from January 2007 to December 2017. It analyzes excess return using event study methodology and studies the determinants of abnormal return with multiple regression analysis. Findings - We find that abnormal returns of the short and long window are positive on average and statistically significant. In particular, CAR of high growth subsample is a larger positive return than that of the low one both short and long window. Difference in abnormal returns by investment size is observed only in short time window. But there is not observed difference by cash holding level. Research implications or Originality - This finding is able to be added to the evidence of the theory of corporate value maximization academically. Moreover, it shows the possibility that building a new office can have a positive effect on corporate value. It is expected to help investors make decisions because it can provide useful information to market participants in practice.

Pohang City Fire Vulnerable Area Prediction and Fire Damage Rating Measurement by Administrative District (포항시 화재 취약지역 예측 및 이에 따른 행정구역별 화재 피해 등급 측정)

  • Lim, Jung-Hoon;Kim, Heon-Joo
    • The Journal of the Korea Contents Association
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    • v.21 no.4
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    • pp.166-176
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    • 2021
  • Due to urbanization and industrialization, the importance of large-scale fire prevention, management and measures is increasing day by day. However, the fire site arrival rate in Golden Time, which is a factor that can minimize large-scale fire damage, of Pohang, a large city with a population of over 500,000, is relatively low. So additional fire fighting power deployment and infrastructure investment are required. However, as budget and manpower are limited, it is necessary to selectively deploy fire fighting power and invest in infrastructure. Therefore, this study attempted to present a fire damage rating that can compare the level of fire damage, which is an index that can help selectively provide fire fighting services in Pohang and make related decisions. For the index, the OD cost matrix was used to predict fire vulnerable areas with a high probability of increasing the fire scale in the event of a fire. Also fire damage was measured by predicting the level of fire damage in the event of a fire according to population, building density, and access of fire trucks. It is expected that the fire damage rating will be able to help in various decisions related to fire fighting service deployment and services not only in Pohang city, but also in other regions.