• 한국환경과학회지
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• 제31권4호
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• pp.329-339
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• 2022

Better understanding the mechanism of black ice occurrence on the road in winter is necessary to reduce the socio-economic damage it causes. In this study, intensive observations of road weather elements and surface information under the influence of synoptic high-pressure patterns (22^nd December, 2020 and 29^th January, and 25^th February, 2021) were carried out using a mobile observation vehicle. We found that temperature and road surface temperature change is significantly influenced by observation time, altitude and structure of the road, surrounding terrain, and traffic volume, especially in tunnels and bridges. In addition, even if the spatial distribution of temperature and road surface temperature for the entire observation route is similar, there is a difference between air and road surface temperatures due to the influence of current weather conditions. The observed road temperature, air temperature and air pressure in Nongong Bridge were significantly different to other fixed road weather observation points.

• 대기
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• 제15권2호
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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.

• 한국건축시공학회지
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• 제5권3호
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• pp.91-99
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• 2005

It is required to study systematical on the concrete quality management to extend structure life because rebuilding effect is reducing under present condition of large sized and high stories structure. Concrete, which shows its intensity by hydrating action and a big change in quality according to hot weather and temperature, produces a lot of qualify problem under hot and cold weather Because of each specification and construction plan which does not have basic standard on site, concrete's quality is irregular and makes some defect. As a result, Daegu is turned out to be the longest area after investigating application period and days focused on 8 cities weather information about relationship between hot weather circumstance and construction environment. Therefore, we first surveyed the concrete material in the region and found out the problem of quality nanagement. Then figure out the way of solution. Moreover, we integrated concrete material quality management, which is applied differently to each site, to have equal quality and to reduce defect from construction site. And then, based on various test of construction condition and analysis of quality management item, we suggest effective concrete quality management to make concrete material construction standard guide and plan under hot weather.

• 대기
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• 제26권3호
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• pp.461-471
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• 2016

A quality check algorithm for the Weather Information Service Engine pulsed Doppler wind lidar is developed from a view point of spatial and temporal consistencies of observed wind speed. Threshold values for quality check are determined by statistical analysis on the standard deviation of 3-component of wind speed obtained by a wind lidar, and the vertical gradient of horizontal wind speed obtained by a radiosonde system. The algorithm includes carrier-to-noise ratio (CNR) check, data availability check, and vertical gradient of horizontal wind speed check. That is, data sets whose CNR is less than -29 dB, data availability is less than 90%, or vertical gradient of horizontal wind speed is less than $-0.028s^{-1}$ or larger than $0.032s^{-1}$ are classified as 'doubtful', and flagged. The developed quality check algorithm is applied to data obtained at Bucheon station for the period from 1 to 30 September 2015. It is found that the number of 'doubtful' data shows maxima around 2000 m high, but the ratio of 'doubtful' to height-total data increases with increasing height due to atmospheric boundary height, cloud, or rainfall, etc. It is also found that the quality check by data availability is more effective than those by carrier to noise ratio or vertical gradient of horizontal wind speed to remove an erroneous noise data.

• 정보처리학회논문지B
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• 제14B권6호
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• pp.445-452
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• 2007

본 논문에서는 도로 상에 설치된 CCTV의 영상정보에서 날씨정보를 검출하기 위한 방법으로 도로날씨정보 검출알고리즘을 제안한다. 도로 상의 CCTV 영상정보에서 날씨정보를 얻는 방법으로 맑은 날의 영상에서 RGB 평균값을 얻고 이를 기준으로 흐린 날 혹은 비 오는 날, 눈 오는 날, 안개 낀 날 등의 영상을 구분한다. 본 논문에서 제안하는 도로날씨정보 검출알고리즘은 많은 시간비용과 공간비용이 소모되는 날씨 데이터베이스를 활용하는 기존의 기법에 비하여, 시간비용과 공간비용이 적게 들기에 시스템을 구축함과 동시에 현장에 적용할 수 있다는 장점이 있다. 또한 본 알고리즘에서는 온 습도 정보와 일자 정보를 이용하여 검출된 날씨 정보를 재검증함으로 보다 정확한 날씨 정보를 검출할 수 있다.

• 대기
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• 제29권2호
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• pp.183-196
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• 2019

High-quality and high-resolution meteorological information is essential to reduce damages due to disastrous weather phenomena such as flash flood, strong wind, and heat/cold waves. There are many meteorological observation stations operated by Korea Meteorological Administration (KMA) in Seoul Metropolitan Area (SMA). Nonetheless, they are still not enough to represent small-scale weather phenomena like convective storm cells due to its poor resolution, especially over urban areas with high-rise buildings and complex land use. In this study, feasibilities to use additional pre-existing networks (e.g., operated by local government and private company) are tested by investigating the effects of network density on the gridded horizontal distribution of two meteorological variables (temperature and precipitation). Two heat wave event days and two precipitation events are chosen, respectively. And the automatic weather station (AWS) networks operated by KMA, local-government, and SKTechX in Incheon area are used. It is found that as network density increases, correlation coefficients between the interpolated values with a horizontal resolution of 350 m and observed data also become large. The range of correlation coefficients with respect to the network density shows large in nighttime rather than in daytime for temperature. While, the range does not depend on the time of day, but on the precipitation type and horizontal distribution of convection cells. This study suggests that temperature and precipitation sensors should be added at points with large horizontal inhomogeneity of land use or topography to represent the horizontal features with a resolution higher than 350 m.

• 대기
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• 제20권2호
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• pp.101-109
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• 2010

The service of health information was provided through internal and external weather agency web sites. The purpose of this study was to analyze current status of the weather agency web sites dealing with health information in the internet, and to evaluate their contents and technical aspects. The evaluation tool consisted of five area (appropriateness, accessibility, supportiveness, feedback, and continuance) with nineteen items. For the public confidence, web sites were limited to national meteorological administration and representative weather agencies. The evaluating web sites were fourteen from eight countries. The evaluation scores of fourteen web sites were 37.8 out of 53.0 in total. Each subcategory score were 5-12 out of 12 in appropriate, 4-12 out of 12 in accessibility, 4-10 out of 11 in supportiveness, 2-8 out of 9 in feedback, and 2-8 out of 9 in continuance. The score of feedback was the lowest. Survey results indicated that Korean Meteorological Administration homepage was middle status compared with the others in side of depth of health information and feedback from expert. Climate change affect human health, so it will be possible to prevent some disease at first through climate information. It should be developed to provide high quality health information and system related climate on KMA homepage.

• 대기
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• 제30권2호
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• pp.169-181
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• 2020

We conducted a study on the impact of observation station density; this was done in order to enable the accurate estimation of spatial meteorological variables. The purpose of this study is to help operate an efficient observation network by examining distributions of temperature, relative humidity, and wind speed in a test area of a three-dimensional meteorological observation project in the Yeongdong region in 2019. For our analysis, we grouped the observation stations as follows: 41 stations (for Step 4), 34 stations (for Step 3), 17 stations (for Step 2), and 10 stations (for Step 1). Grid values were interpolated using the kriging method. We compared the spatial accuracy of the estimated meteorological grid by using station density. The effect of increased observation network density varied and was dependent on meteorological variables and weather conditions. The temperature is sufficient for the current weather observation network (featuring an average distance about 9.30 km between stations), and the relative humidity is sufficient when the average distance between stations is about 5.04 km. However, it is recommended that all observation networks, with an average distance of approximately 4.59 km between stations, be utilized for monitoring wind speed. In addition, this also enables the operation of an effective observation network through the classification of outliers.

• 대기
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• 제25권2호
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• pp.339-351
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• 2015

The purpose of this study is for the fundamental understandings about building morphological parameters and aerodynamic roughness parameters of Seoul, Korea using the detailed urban geographic information datasets. Applied roughness parameter calculations are based on a digital map of buildings with lot area polygons. The quality of the developed roughness length ($z_0$) of Seoul was evaluated with densely installed 107 automatic weather stations. The correlation coefficient results between averaged wind speeds of AWS data and averaged $z_0$ is -0.303 in night and -0.398 in day (200 m radii circles case). Further $z_0$ enhancement should follow by considering other surface features such as high tree and orography of Seoul. However, this study would meet the needs to for local- or meso-scale meteorological modeling applications of Seoul. However, further studies would require for enhancing the $z_0$ applications of Seoul.

• 한국환경과학회지
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• 제28권11호
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• pp.1047-1059
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• 2019

To address the increase of weather hazards and the emergence of new types of such hazards, an optimization technique for three-dimensional (3D) representation of meteorological facts and atmospheric information was examined in this study as a novel method for weather analysis. The proposed system is termed as "meteorological and air quality information visualization engine" (MAIVE), and it can support several file formats and can implement high-resolution 3D terrain by employing a 30 m resolution digital elevation model. In this study, latest 3D representation techniques such as wind vector fields, contour maps, stream vector, stream line flow along the wind field and 3D volume rendering were applied. Implementation of the examples demonstrates that the results of numerical modeling are well reflected, and new representation techniques can facilitate the observation of meteorological factors and atmospheric information from different perspectives.