• Title/Summary/Keyword: Weather conditions

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Atmospheric Dispersion Characteristics of Radioactive Materials according to the Local Weather and Emission Conditions

  • An, Hye Yeon;Kang, Yoon-Hee;Song, Sang-Keun;Kim, Yoo-Keun
    • Journal of Radiation Protection and Research
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    • v.41 no.4
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    • pp.315-327
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    • 2016
  • Background: This study evaluated the atmospheric dispersion of radioactive material according to local weather conditions and emission conditions. Materials and Methods: Local weather conditions were defined as 8 patterns that frequently occur around the Kori Nuclear Power Plant and emission conditions were defined as 6 patterns from a combination of emission rates and the total number of particles of the $^{137}Cs$, using the WRF/HYSPLIT modeling system. Results and Discussion: The highest mean concentration of $^{137}Cs$ occurred at 0900 LST under the ME4_1 (main wind direction: SSW, daily average wind speed: $2.8ms^{-1}$), with a wide region of its high concentration due to the continuous wind changes between 0000 and 0900 LST; under the ME3 (NE, $4.1ms^{-1}$), the highest mean concentration of $^{137}Cs$ occurred at 1500 and 2100 LST with a narrow dispersion along a strong northeasterly wind. In the case of ME4_4 (S, $2.7ms^{-1}$), the highest mean concentration of $^{137}Cs$ occurred at 0300 LST because $^{137}Cs$ stayed around the KNPP under low wind speed and low boundary layer height. As for the emission conditions, EM1_3 and EM2_3 that had the maximum total number of particles showed the widest dispersion of $^{137}Cs$, while its highest mean concentration was estimated under the EM1_1 considering the relatively narrow dispersion and high emission rate. Conclusion: This study showed that even though an area may be located within the same radius around the Kori Nuclear Power Plant, the distribution and levels of $^{137}Cs$ concentration vary according to the change in time and space of weather conditions (the altitude of the atmospheric boundary layer, the horizontal and vertical distribution of the local winds, and the precipitation levels), the topography of the regions where $^{137}Cs$ is dispersed, the emission rate of $^{137}Cs$, and the number of emitted particles.

A Method of All-Weather Construction Application in Construction Sites (건설분야 전천후 공법 적용방안)

  • Lee, Han-Woo;Lee, Byung-Soo;Bang, Chang-Joon
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.11a
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    • pp.193-194
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    • 2012
  • Construction work is affected by the weather; e.g. snowfall, rainfall and low-high ambient temperature, especially at a site in a severe climate. The influence of the weather is one of the possible reasons for delays in a construction schedule and quality deterioration. To protect the worksite from severe weather conditions, the temporary roof and wall could be installed on the outside of main structures designed in advance and the temporary structures could be took down after a period use. The greater coverage all-weather construction method is applied, the larger the effect. so, it is important and needs that the temporary roof and wall can be widely applied, designed to effectively about structure and layout.

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The Analysis of the Supercomputer Trends in Weather and Climate Research Areas (기상 및 기후 연구 분야의 슈퍼컴퓨터 보유 추이 분석)

  • Joh, Minsu;Park, Hyei-Sun
    • Atmosphere
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    • v.15 no.2
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    • pp.119-127
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    • 2005
  • It is challenging work to predict weather and climate conditions of the future in advance. Since ENIAC was developed, weather and climate research areas have been taking advantage of the improvements in computer hardware. High performance computers allows researchers to build high quality models that allow them to make good predictions of what might happen in the future. Statistics on the high performance computers are one of the major interest to not only manufacturers but also the users such as weather and climate researchers. For this reason, the Top500 Supercomputer Sites Report has been being released twice a year since 1993 to provide a reliable basis for tracking and detecting trends in high performance computing. Using the Top500 Report, a short review on the supercomputer trends in weather and climate research areas is provided in this article.

A STUDY OF SHOULDERING OF COMPENSATORY LIABILITY FOR DELAYED CONSTRUCTION FERIODS FOLLOWING BAD WEATHER CONDITIONS

  • Tae-Sang Jeong ; Yong-Su Kim
    • International conference on construction engineering and project management
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    • 2005.10a
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    • pp.705-708
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    • 2005
  • In the case that construcion period is delayed because of the force majeure such as a typhoon or a flood, the owners in general should compensate the damages caused by those. But with exception the weather worsening of ordinary level is paid by contractors, while that of exceptional level by the owners. It is critical that it is difficult to distinguish objectively between ordinary and exceptional level weather worsening. Although the term of "ordinary" itself is too abstractive, we can reduce the disputes between owners and contractors by setting the appropriate and objective standard of distinction. For example in the case of rainfall it may be the standard of distinction whether the days of actual rainfall exceed those of average rainfall or not. If the days of actual rainfall don't exceed those of average rainfall contracters should pay the damages because it is distinguished with a ordinary level weather worsening. Besides the standard of distinction in another weather worsening such as severe cold/hot, strong wind etc. which have a effect on delaying the term of works could be settled as a similar model.

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Study of the Relationship between the Pain and the Weather (통증과 날씨와의 관련성 연구)

  • Lee, Chong-Woo;Kwon, Young-Dal
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.21 no.2
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    • pp.571-577
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    • 2007
  • The purpose of this study was to investigate the relationship between the pain and the weather. One hundred ninety three patients treated for pain were recruited for this study. All subjects completed a 8-item weather and pain questionnaire to find out whether the pain are related to change in the weather, Of all subjects, 126 patients(65.3%) believed that change in the weather affected their pain. Of theses 126 patients, 85 patients(67.5%) reported that their pain was affected before weather changes, 44 patients(34.9%) stated that their pain was affected during weather changes. Damp/Rainy(n=91, 72.2%) and cold(n=60, 47.6%) conditions were mostly considered to have influence on pain. Of all subjects, 125 patients(64.8%) believed that change in the weather affected their mood. In the female group, a tendency to have pain or mood sensitivity to change in the weather was significantly higher than the male group(p=0.006, p=0.003) In the non-religious group, a tendency to have pain or mood sensitivity to change in the weather was significantly higher than the religious group(p=0.006, p=0.004). Of the pain sensitive group to change in the weather, 97 patients(77.0%) reported that they also have mood sensitivity to change in the weather(p=0.000). In the pain or mood sensitive group to change in the weather, their pain intensity(VAS) was significantly higher than the other group(p=0.000, p=0.021). The results of this survey give support to the idea that most patients with pain believe that weather has an important impact on their pain. Further investigations are needed to identify the mechanisms involved in the effects of weather changes on pain.

Field Application of High Strength Concrete under Cold Weather Conditions (650kgf/$\textrm{cm}^2$ 고강도 콘크리트 한중 시공사례)

  • 정재동;노재호;한정호;조일호
    • Proceedings of the Korea Concrete Institute Conference
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    • 1994.04a
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    • pp.260-265
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    • 1994
  • High strength concrete(65MPa) was used for construction of the bulk cement storage silo by using sliding form. This paper presents mix design, production, quality control and experience with field application of high strength concrete under cold weather conditions. It is shown to be possible to produce high strength concrete of compressive strength of 50~60 MPa by using high-range water reducer to lower w/c ratio with appropriate quality control.

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Tropospheric Anomaly Detection in Multi-Reference Stations Environment during Localized Atmospheric Conditions-(2) : Analytic Results of Anomaly Detection Algorithm

  • Yoo, Yun-Ja
    • Journal of Navigation and Port Research
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    • v.40 no.5
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    • pp.271-278
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    • 2016
  • Localized atmospheric conditions between multi-reference stations can bring the tropospheric delay irregularity that becomes an error terms affecting positioning accuracy in network RTK environment. Imbalanced network error can affect the network solutions and it can corrupt the entire network solution and degrade the correction accuracy. If an anomaly could be detected before the correction message was generated, it is possible to eliminate the anomalous satellite that can cause degradation of the network solution during the tropospheric delay anomaly. An atmospheric grid that consists of four meteorological stations was used to detect an inhomogeneous weather conditions and tropospheric anomaly applied AWSs (automatic weather stations) meteorological data. The threshold of anomaly detection algorithm was determined based on the statistical weather data of AWSs for 5 years in an atmospheric grid. From the analytic results of anomaly detection algorithm it showed that the proposed algorithm can detect an anomalous satellite with an anomaly flag generation caused tropospheric delay anomaly during localized atmospheric conditions between stations. It was shown that the different precipitation condition between stations is the main factor affecting tropospheric anomalies.

Setting of the Operating Conditions of Stereo CCTV Cameras by Weather Condition

  • Moon, Kwang;Pyeon, Mu Wook;Lee, Soo Bong;Lee, Do Rim
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.32 no.6
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    • pp.591-597
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    • 2014
  • A wide variety of image application methods, such as aerial image, terrestrial image, terrestrial laser, and stereo image point are currently under investigation to develop three-dimensional 3D geospatial information. In this study, matching points, which are needed to build a 3D model, were examined under diverse weather conditions by analyzing the stereo images recorded by closed circuit television (CCTV) cameras installed in the U-City. The tests on illuminance and precipitation conditions showed that the changes in the number of matching points were very sensitively correlated with the changes in the illuminance levels. Based on the performances of the CCTV cameras used in the test, this study was able to identify the optimal values of the shutter speed and iris. As a result, compared to an automatic control mode, improved matching points may be obtained for images filmed using the data obtained through this test in relation to different weather and illuminance conditions.

Analysis of the Outdoor Design Conditions for Greenhouse Heating and Cooling Systems in Korea (온실의 냉난방시스템 설계용 외부기상조건 분석)

  • Nam, Sang-Woon;Shin, Hyun-Ho
    • Journal of Bio-Environment Control
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    • v.25 no.4
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    • pp.308-319
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    • 2016
  • In order to set the outdoor weather conditions to be applied to the design standard of the greenhouse heating and cooling system, outdoor air temperature and heating degree-hour for heating design, dry bulb temperature, wet bulb temperature and solar irradiance for cooling design were analyzed and presented. For every region in Korea, we used thirty years from 1981 to 2010 hourly weather data for analysis, which is the current standard of climatological normal provided by KMA. Since the use of standard weather data is limited, design weather conditions were obtained using the entire weather data for 30 years, and the average value of the entire data period was presented as a design standard. The design weather data with exceedance probability of 1, 2.5, and 5% were analyzed by the TAC method, and we presented the distribution map with exceedance probability of 1% for heating and 2.5% for cooling which are recommended by design standards. The changes of maximum heating load, seasonal heating load and maximum cooling load were examined by regions, exceedance probabilities, and setpoint temperatures. The proposed outdoor design conditions can be used not only directly for the greenhouse heating and cooling design, but also for the reinforcement of heating and cooling facilities and the establishment of energy saving measures. Recently, due to the climate change, sweltering heat in summer and abnormal temperature in winter are occurring frequently, so we need to analyze weather data periodically and revise the design standard at least every 10 years cycle.

A Study on The Relationship Between Driver Expectancy and Variable Speed Limit Under the Adverse Weather Conditions By Using A Driving Simulator (악천후 시 운전자 기대심리와 가변 제한속도간 관계정립을 위한 가상주행 시뮬레이터 연구)

  • Kim, Yongseok;Lee, Sukki;Kim, Soullam
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.15 no.6
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    • pp.138-149
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    • 2016
  • The study reviewed the effects of the variable speed limit under adverse weather conditions by using a driving simulator. The study assumed that the display of the reduced speed limit without any change of the weather condition and the display of the same speed limit under the change of the weather conditions violate the expectancy of drivers, so it brings the negative effects on the safety. The study regards drivers conformance as the index of the degree of the compliance of driver expectancy, and utilizes the cumulative probability density within the certain range of the speed including displayed speed limit as the quantitative measure of effectiveness. The study reviewed this assumptions by using a driving simulator. As the results, the cases assumed to violate the expectancy of drivers showed the negative effects on the driving behaviour of driver relatively.