• Title/Summary/Keyword: wind direction data analysis

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Analysis of the Spatial Distribution of Pan Evaporation Trends (Pan 증발량 추세분포 분석)

  • Rim, Chang-Soo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.30 no.3B
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    • pp.243-255
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    • 2010
  • The spatial distribution of pan evaporation and pan evaporation trends have been studied. In this study, pan evaporation data from 1973 to 1990 for 56 climatological stations were analyzed. In addition to annual average daily pan evaporation, monthly average daily pan evaporation in April, July, October and January were analyzed, considering seasonal effect. The study results indicate that in case of annual average daily pan evaporation, 38 stations out of 56 stations show decreasing trend. In case of average daily pan evaporation in January, 33 stations show decreasing trend. In April, 38 stations show increasing trend. In July, 47 stations show decreasing trend. In October, 35 stations show increasing trend. Therefore, on the whole, pan evaporation tended to decrease in January, July, and annual basis. On the other hand, pan evaporation tended to increase in April and October. Furthermore, pan evaporation trend in each individual region shows also different trend even though the region is located nearby, indicating that there are geographical and topographical effects on pan evaporation trend. Pan evaporation data and climatic data from 1973 to 2006 for 11 climatological stations were used for trend analysis. Climatic variables such as temperature, relative humidity and wind speed show same or opposite trend direction compared with pan evaporation in annual or monthly basis. Annual and monthly solar radiation trends show the same direction compared with pan evaporation; however, annual and monthly precipitation trends show the opposite direction compared with pan evaporation.

A Phenomenological Perspective and Meaning of joint-pain's Experience of Women's in an island (관절통을 경험한 도서지역 여성의 체험연구)

  • Kim, Gan-Woo
    • Journal of muscle and joint health
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    • v.5 no.2
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    • pp.265-285
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    • 1998
  • This Qualitative nursing research was made with a hermeneutic phenomenological approach to find out the meaning and nature of human's experience. The purpose of the inquiry is to find out the meaning and to understand the nature of Joint pain's experience of women in the island and to apply the result to nursing practice. The study was guided by Shin Kyung Rim's four step that revised van Manen's method for doing research. The method of inquiry included : turning to interesting phenomenon. inquiring and investigating experience as it was lived rather than as conceptualized ; reflecting and analyzing essential themes which characterize phenomenon ; and describing phenomenon through art and literature. Multiple strategies for data collecting were needed : deep face to face interview ; analysis of joint pain of women's writings ; describing and analysis of examples of the phenomenon in art, literature. Through this process essensial them of the experience was emerged : Misery that I would like to cut off my body, Sea wind soaking deeply into the bones, Dull pain from the postpartum cold wind, The another suffer I should endure by myself, Recrudesce despite all the try I have made, Often forgetting the pain of every Joint for hardship of life. Findings from artistic and creative inquiry further was validated and meaning was discovered. The study illuminated meaning and simultaneously validated the phenomenological research process. Essential themes for understanding women joint pain's experience, implications, for education, research and practice, direction and need for continuing inquiry were identified.

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Optimization of Fugitive Dust Control System for Meteorological Conditions (기상조건별 비산먼지 관리체계 최적화 연구)

  • Kim Hyun-Goo
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.6
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    • pp.573-583
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    • 2005
  • Fugitive dust, which is emitted in the ambient air without first passing through a stack or duct designed to control flow, is frequently generated by means of wind erosion from storage yards at Pohang Steel Wokrs. The size distribution of fugitive dust is mostly in the range of coarse particulate which is deposited as soon as emitted and less harm to human health; however $20\%$ of fugitive dust contains PM 10 known as one of most harmful airborne pollutant. Consequently, effective control and reduction of fugitive dust is strongly requested by the local society, but it is not easy so far because the generation and dispersion of fugitive dust highly depends on meteorological conditions, and it being occurred for irregularity. This research presented a fugitive dust control system for each meteorological condition by providing statistical prediction data obtained from a statistical analysis on the probability of generating the threshold velocity at which the fugitive dust begins to occur, and the frequency occurring by season and by time of the wind direction that can generate atmospheric pollution when the dispersed dust spreads to adjacent residential areas. The research also built a fugitive dust detection system which monitors the weather conditions surrounding storage yards and the changes in air quality on a real-time basis and issues a warning message by identifying a situation where the fugitive dust disperses outside the site boundary line so that appropriate measures can be taken on a timely basis. Furthermore, in respect to the spraying of water to prevent the generation of fugitive dust from the storage piles at the storage yard, an advanced statistical meteorological analysis on the weather conditions in Pohang area and a case study of fugitive dust dispersion toward outside of working field during $2002\∼2003$ were carried out in order to decide an optimal water-spraying time and the number of spraying that can prevent the origin of fugitive dust emission. The results of this research are expected to create extremely significant effects in improving surrounding environment through actual reduction of the fugitive dust produced from the storage yard of Pohang Steel Works by providing a high-tech warning system capable of constantly monitoring the leakage of fugitive dust and water-spray guidance that can maximize the water-spraying effects.

Analysis of Meteorological Features and Prediction Probability Associated with the Fog Occurrence at Chuncheon (춘천의 안개발생과 관련된 기상특성분석 및 수치모의)

  • Lee Hwa Woon;Lee Kwi Ok;Baek Seung-Joo;Kim Dong Hyeok
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.3
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    • pp.303-313
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    • 2005
  • In this study, meteorological characteristics concerning the occurrence of fog are analyzed using 4-years $(2000\~2003)$ data at Chuncheon and the probability of prediction is investigated. From the analysis of meteorological characteristics, the fog at Chuncheon occurred before sunrise time and disappeared after that time and lasted for $2\~4$ hours. When fog occurred, on the whole, wind direction was blew the northerly and wind speed was below 2.1m/s. Especially, about $42\%$ of foggy day fell on the calm $(0\~0.2\;ms^{-1})$ conditions. The difference between air temperature and dew point temperature near the surface were mainly less than $2^{\circ}C$. For the lack of water surface temperature, the water surface temperature was calculated by using Water Quality River Reservoir System (WQRRS) and then it was used as the surface boundary condition of MM5. The numerical experiment was carried out for 2 days from 1300 LST on 14 October 2003 to 1300 LST on 16 October 2003 and fog was simulated at dawn on 15 and 16 October 2003. Simulated air temperature and dew point temperature indicate the similar tendency to observation and the simulated difference between air temperature and dew point temperature has also the similar tendency within $2^{\circ}C$. Thus, the occurrence of fog is well simulated in the terms of the difference between air temperature and dew point temperature. Horizontal distribution of the difference between air temperature and dew point temperature from the numerical experiment indicates occurrence, dissipation and lasting time of fog at Chuncheon. In Chuncheon, there is close correlation between the frequency of fog day and outflow from Soyang reservoir and high frequency of occurrence due to the difference between air and cold outlet water temperature.

The Performance Assessment of Special Observation Program (ProbeX-2009) and the Analysis on the Characteristics of Precipitation at the Ulleungdo (울릉도 특별관측 수행평가 및 강수특성 분석)

  • Kim, Ki-Hoon;Kim, Yeon-Hee;Kim, Do-Woo;Chang, Dong-Eon
    • Atmosphere
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    • v.21 no.2
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    • pp.185-196
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    • 2011
  • The performance assessment in radiosonde observation on the special observation program (ProbeX-2009) is performed and the characteristics of precipitation using Auto Weather System (AWS) and radiosonde data in 2009 at the Ulleungdo are investigated. The launching time, observation time, and maximum altitude of radiosonde are satisfied with the regulation from Korea Meteorological Administration (KMA) and World Meteorological Organization (WMO) but the duration of observational time of radiosonde is much shorter than that of the ProbeX-2007 because the altitude of launching site is higher than others in 2007. From the analysis of trajectories of radiosonde, most radiosondes at the Ulleungdo tend to move into the east because the westerly prevail at the middle latitude. However, when the Okhotsk high is expanded to the Korean peninsula and the north-westerly winds strengthen over the East Sea as the subtropical high is retreated, radiosonde tends to move into the south-west and south-east, respectively. Maximum distance appears at the end of observation level before May but the level of maximum distance is changed into 100 hPa after June because the prevailing wind direction is reversed from westerly to easterly at the stratosphere during summer time. The condition of precipitation was more correlated with the dynamic instability except Changma season. Precipitation in 2009 at the Ulleungdo occurred under the marine climate so that total precipitation amounts and precipitation intensity were increased and intensified during nighttime. The local environment favorable for the precipitation during nighttime was while the wind speed at the surface and the inflow from the shoreline were strengthened. Precipitation events also affected by synoptic condition but the localized effect induced by topography was more strengthened at the northern part of Ulleungdo.

Air Quality Impact Analysis for Point Sources Using Three-Dimensional Numerical Models (삼차원 수치모델을 이용한 점오염원의 대기환경영향 평가)

  • 김영성;오현선;김진영;강성대;조규탁;홍지형
    • Journal of Korean Society for Atmospheric Environment
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    • v.17 no.4
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    • pp.331-345
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    • 2001
  • The increase of carbon monoxide in the ambient air due to the emissions from point sources without control was estimated using three -dimensional numerical models. The target area was Ulsan where one of the largest industrial complexes was located. As a typical example using numerical models for air quality impact analysis of criteria pollutants that will determine whether the air quality standards would be exceeded or not, the following approaches were suggested. They include: (1) investigation of pre-existing atmospheric conditions, (2) identification of major factors causing high concentrations, (3) selection of episode days. (4) preparation of three-dimensional meteorological data, (5) confirmation of agreement between measured and predicted concentrations in the emission conditions of episode days, and (6) estimation of the impact due to changes of the emission conditions. In the present work, daily meteorological conditions for the specific period were classified into four clusters of distinctive features, and the episode days were selected individually from each cluster. Emphasis was placed on the selection of episodes representing meteorological conditions conducive to high concentrations especially for point sources that were sensitive to the wind direction variations.

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Topic Model Analysis of Research Trend on Renewable Energy (신재생에너지 동향 파악을 위한 토픽 모형 분석)

  • Shin, KyuSik;Choi, HoeRyeon;Lee, HongChul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6411-6418
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    • 2015
  • To respond the climate change and environmental pollution, the studies on renewable energy policies are increasing. The renewable energy is a new growth engine technology represented by the green industry and green technology. At present, the investments for the renewable energy supply and technology development projects of three main strategy sectors such as sunlight, wind power and hydrogen fuel cell are implemented in our country, while they are still in the early stage, accordingly reducing those uncertainty for the research direction and investment fields is the most urgent issue among others. Thus, this study applied text mining method and multinominal topic model among the big data analysis methods on our country's newspaper articles concerning the renewable energy over the last 10 years, and then analyzed the core issues and global research trend, forecasting the renewable energy fields with the growth potential. It is predicted that these results of the study based on information and communication technology will be actively applied on the renewable energy fields.

Impact by Estimation Error of Hourly Horizontal Global Solar Radiation Models on Building Energy Performance Analysis on Building Energy Performance Analysis

  • Kim, Kee Han;Oh, John Kie-Whan
    • KIEAE Journal
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    • v.14 no.2
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    • pp.3-10
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    • 2014
  • Impact by estimation error of hourly horizontal global solar radiation in a weather file on building energy performance was investigated in this study. There are a number of weather parameters in a given weather file, such as dry-bulb, wet-bulb, dew-point temperatures; wind speed and direction; station pressure; and solar radiation. Most of them except for solar radiation can be easily obtained from weather stations located on the sites worldwide. However, most weather stations, also including the ones in South Korea, do not measure solar radiation because the measuring equipment for solar radiation is expensive and difficult to maintain. For this reason, many researchers have studied solar radiation estimation models and suggested to apply them to predict solar radiation for different weather stations in South Korea, where the solar radiation is not measured. However, only a few studies have been conducted to identify the impact caused by estimation errors of various solar radiation models on building energy performance analysis. Therefore, four different weather files using different horizontal global solar radiation data, one using measured global solar radiation, and the other three using estimated global solar radiation models, which are Cloud-cover Radiation Model (CRM), Zhang and Huang Model (ZHM), and Meteorological Radiation Model (MRM) were packed into TRY formatted weather files in this study. These were then used for office building energy simulations to compare their energy consumptions, and the results showed that there were differences in the energy consumptions due to these four different solar radiation data. Additionally, it was found that using hourly solar radiation from the estimation models, which had a similar hourly tendency with the hourly measured solar radiation, was the most important key for precise building energy simulation analysis rather than using the solar models that had the best of the monthly or yearly statistical indices.

An Agroclimatic Data Retrieval and Analysis System for Microcomputer Users(CLIDAS) (퍼스컴을 이용한 농업기후자료 검색 및 분석시스템)

  • 윤진일;김영찬
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.38 no.3
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    • pp.253-263
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    • 1993
  • Climatological informations have not been fully utilized by agricultural research and extension workers in Korea due mainly to inaccessbilty to the archived climate data. This study was initiated to improve access to historical climate data gathered from 72 weather stations of Korea Meteorological Administration for agricultural applications by using a microcomputer-based methodology. The climatological elements include daily values of average, maximum and minimum temperature, relative humidity, average and maximum wind speed, wind direction, evaporation, precipitation, sunshine duration and cloud amount. The menu-driven, user-friendly data retrieval system(CLIDAS) provides quick summaries of the data values on a daily, weekly and monthly basis and selective retrieval of weather records meeting certain user specified critical conditions. Growing degree days and potential evapotranspiration data are derived from the daily climatic data, too. Data reports can be output to the computer screen, a printer or ASCII data files. CLIDAS can be run on any IBM compatible machines with Video Graphics Array card. To run the system with the whole database, more than 50 Mb hard disk space should be available. The system can be easily upgraded for further expansion of functions due to the module-structured design.

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Feasibility Study for Derivation of Tropospheric Ozone Motion Vector Using Geostationary Environmental Satellite Measurements (정지궤도 위성 대류권 오존 관측 자료를 이용한 대류권 이동벡터 산출 가능성 연구)

  • Shin, Daegeun;Kim, Somyoung;Bak, Juseon;Baek, Kanghyun;Hong, Sungjae;Kim, Jaehwan
    • Korean Journal of Remote Sensing
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    • v.38 no.6_1
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    • pp.1069-1080
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    • 2022
  • The tropospheric ozone is a pollutant that causes a great deal of damage to humans and ecosystems worldwide. In the event that ozone moves downwind from its source, a localized problem becomes a regional and global problem. To enhance ozone monitoring efficiency, geostationary satellites with continuous diurnal observations have been developed. The objective of this study is to derive the Tropospheric Ozone Movement Vector (TOMV) by employing continuous observations of tropospheric ozone from geostationary satellites for the first time in the world. In the absence of Geostationary Environmental Monitoring Satellite (GEMS) tropospheric ozone observation data, the GEOS-Chem model calculated values were used as synthetic data. Comparing TOMV with GEOS-Chem, the TOMV algorithm overestimated wind speed, but it correctly calculated wind direction represented by pollution movement. The ozone influx can also be calculated using the calculated ozone movement speed and direction multiplied by the observed ozone concentration. As an alternative to a backward trajectory method, this approach will provide better forecasting and analysis by monitoring tropospheric ozone inflow characteristics on a continuous basis. However, if the boundary of the ozone distribution is unclear, motion detection may not be accurate. In spite of this, the TOMV method may prove useful for monitoring and forecasting pollution based on geostationary environmental satellites in the future.